This PDF file contains the front matter associated with SPIE Proceedings Volume 9903, including the Title Page, Copyright information, Table of Contents, Introduction (if any), and Conference Committee listing.

Optical phantoms are commonly used to validate and calibrate biomedical optical devices in order to ensure accurate measurement of optical properties in biological tissue. However, commonly used optical phantoms are based on homogenous materials that reflect neither optical properties nor multi-layer heterogeneities of biological tissue. Using these phantoms for optical calibration may result in significant bias in biological measurement. We propose to characterize and fabricate tissue simulating phantoms that simulate not only the multi-layer heterogeneities but also optical properties of biological tissue. The tissue characterization module detects tissue structural and functional properties in vivo. The phantom printing module generates 3D tissue structures at different scales by layer-by-layer deposition of phantom materials with different optical properties. The ultimate goal is to fabricate multi-layer tissue simulating phantoms as a traceable standard for optimal calibration of biomedical optical spectral devices.

Precision roller with microstructures is the key tooling component in the precision embossing by roller process such as Roll-to-Roll to manufacture optical plastic plates or films with three dimensional (3D)-microstructures. Measurement and analysis of 3D-microstructures on a precision roller is essential before the embossing process is being undertaken to ensure the quality of the embossed surfaces. Different from 3D-microstructures on a planar surface, it is difficult to measure and characterize the 3D-microstructures on the cylindrical surface of a precision roller due to the geometrical complexity of such integrated surfaces such as V-groove microstructures on a cylindrical surface. This paper presents a study of method and algorithms for the measurement and characterization of 3D-microstructures on a precision roller surface. A feature-based characterization method (FBCM) is proposed to analyze the V-groove microstructures. In this method, a normal template is generated based on the design specifications, and the measured data is fitted with the feature points. Hence alignment and matching of the measured data to the normal template based on the derived feature points are undertaken. After that the V-groove is characterized by some feature parameters such as pitch, depth, angle of the V-grooves. The method also provides an approach for the analysis of burs generated during the machining of Vgroove microstructures. A precision roller with V-groove microstructures has been machined by a Four-axis ultraprecision machine and the machined surface is measured by a contact measuring instrument. The measured data are then characterized and analyzed by the proposed FBCM. The results are presented and discussed, and they indicate the dominant and regular machining errors that are involved in the machining of the V-groove microstructures on roller surfaces.

Carbon fiber reinforced polymers has been widely used in all kind of the industries. However the internal defects can result in the change of material or mechanical properties, and cause safety problem. In this study, step-heating thermography is employed to measure the time series temperature distribution of composite plate. The principle of heat conduction in a flat plate with defect inside is introduced. A temperature separation criterion to determine the depth of defect inside the specimen is obtained experimentally. Applying this criterion to CFRP specimens with embedded defects, the depth of embedded defect in CFRP can be determined quite well from the time series thermograms obtained experimentally.

This paper describes a method of non-contact distance measurement in high temperature environments by video extensometer. In order to detect the distance of a pair of marked lines on the surface of the specimen, dual fitting algorithms are proposed. The first fitting method which is least squares curve fitting utilizes hyperbolic tangent function to fit a serial of discrete gray level points to a curve. So a set of edge points on the marked line was located. The second is to use orthogonal linear least squares method to fit two sets of edge points to two lines respectively. After the two lines are located, the distance of two lines can be computed. A video extensometer system which enables a high temperature distance measurement up to 1200°C is presented and demonstrated by experimental measurements.

Digital Image Correlation (DIC) is a full-field technique based on white-light illumination for displacement and strain measurement. But radiation on the specimen surface at high temperature affects the quality of acquired speckle pattern images for traditional DIC measurement. In order to minimize the radiation effect in high temperature measurement, this paper proposes a two-dimensional ultraviolet digital image correlation system (2D UV-DIC) containing UV LED and UV band-pass filter. It is confirmed by experiments that images acquired by this system saturate at higher temperature in comparison with DIC using filtered blue light imaging system. And the UV-DIC remains minimally affected by radiation at the temperature which is nearing the specimen’s maximum working temperature (about 1250°C). In addition, considering the heat disturbance that can’t be ignored in actual high temperature measurement, this paper also proposes a method using an air controller in combination with image average algorithm, and the method was then used to obtain the thermal expansion coefficient of the Austenitic chromium-nickel stainless steel specimen at different temperatures. By comparing the coefficients with the results calculated by other method, it shows that this comprehensive method has the advantages of strong anti-interference ability and high precision.

A new type femtosecond laser tracker is one high precision measurement instrument with urgent need in science research region and industrial manufacture field. This paper focuses on the operational principle and the structure development of the femtosecond laser tracer, and the method of error compensation as well. The system modules were studied and constructed. The femtosecond frequency comb module was firstly analyzed and developed. The femtosecond laser frequency comb performed perfectly high precise distance measurement for laser tracker. The experimental result showed that the stability of repetition rate reached 3.0×10^-12@1s and the stability of carrier envelop offset reached 1.0×10^-10@1s. The initial experiment showed that measurement error was less than 1ppm. Later the error compensation module was introduced, and the optoelectronic aiming and tracking control module was built. The actual test result showed that the stability of miss distance was better than 2.0 μm, the tracking speed could reach 2m/s.

Flat panel displays have been used in a wide range of electronic devices. The defects on their surfaces are an important factor affecting the product quality. Automated optical inspection (AOI) method is an important and effective means to perform the surface defection inspection. In this paper, a kind of defect extraction algorithm based on one dimensional (1D) Fourier theory for the surface defect extraction with periodic texture background is introduced. In the algorithm, the scanned surface images are firstly transformed from time domain to frequency domain by 1D Fourier transform. The periodic texture background on the surface is then removed by using filtering methods in the frequency domain. Then, a dual-threshold statistical control method is applied to separate the defects from the surface background. Traditional 1D Fourier transform scheme for detecting ordinary defects is very effective; however, the method is not where the defect direction is close to horizontal in periodic texture background. In order to tackle the problem, a mean threshold method based on faultless image is put forward. It firstly calculates the upper and lower control limits of the every reconstructed line scanned image with faultless and then computes the averages of the upper and lower limits. The averages then act as the constant double thresholds to extract the defects. The experimental results of different defects show that the method developed in the paper is very effective for TFT-LCD panel surface defect inspection even in the circumstance that the defect directions are close to horizontal.

In order to compensate three-dimensional (3D) angle errors of two-dimensional (2D) stage in motion, a 3D angle errors detection and compensation system using a modified DVD pick-up head has been developed in this paper. The modified DVD pick-up head, which consists of a commercial DVD pick-up head without objective lens and voice coil motor, is used as an angle sensor. The mechanism of the angle sensor is based on optical auto-collimation, and each sensor can detect two deflection angles of the stage simultaneously. Utilizing the angle error information obtained by two angle sensors which are set along X and Y moving direction respectively, the controlling system adjusts the nano-positioning stage by controlling the piezoelectric ceramic actuators’ movement to compensate the angle errors of the stage. This system can achieve the measurement and compensation of yaw angle error, pitch angle error and roll angle error of the stage. Experimental results show that the angle detection range of this system is ±110", the resolution is about 0.2", and the repeatability error is about 2″. After compensating, the 3D angle errors of 2D stage can be controlled within 3″. This system has the advantages of compact structure, low cost, etc.

The reasonable permanent magnetic field distribution has an important influence on improving the measuring accuracy in intelligent ball joint. In view of the defects on the ring permanent magnet in the previous experiment scheme, a new method on Square Pane Permanent Magnet (SPPM) is put forward. It possesses distinct advantages on orientation identification and model simplification. This paper proposes an optimized theory model of the magnetic field distribution of SPPM and gives the magnetic field theoretical expressions. The experiments have shown that the experimental data basically agreed with the theory value which is less than 4.3% error in full scale. This result verified the correctness of the analytic work and paves the way for improving the measurement accuracy in intelligent ball joint.

Motion error of slider plays key role in 3-PUU parallel coordinates measuring machine (CMM) performance and influence the CMM accuracy, which attracts lots of experts eyes in the world, Generally, the analysis method is based on the view of space 6-DOF. Here, a new analysis method is provided. First, the structure relation of slider and guideway can be abstracted as a 4-bar parallel mechanism. So, the sliders can be considered as moving platform in parallel kinematic mechanism（PKM）. Its motion error analysis is also transferred to moving platform position analysis in PKM. Then, after establishing the positive and negative solutions, some existed theory and technology for PKM can be applied to analyze slider straightness motion error and angular motion error simultaneously. Thirdly, some experiments by autocollimator are carried out to capture the original error data about guideway its own error, the data can be described as straightness error function by fitting curvilinear equation. Finally, the Straightness error of two guideways are considered as the variation of rod length in parallel mechanism, the slider’s straightness error and angular error can be obtained by putting data into the established model. The calculated result is generally consistent with experiment result. The idea will be beneficial on accuracy calibration and error correction of 3-PUU CMM and also provides a new thought to analyze kinematic error of guideway in precision machine tool and precision instrument.

According to the dynamic tension testing requirements of the multi-rope winder rope, this paper designs the sensor used to measure the tension of steel wire rope directly. The sensor uses the strain shear measuring principle, and has many features with small size, big measuring range, easy to install, don’t change the structure of connected devices and so on. Application of the finite element analysis software makes the structure of the sensor optimized, and then enhance the static and dynamic performance of the sensor.

Pressure transducer is widely used in the field of industry. A calibrated pressure transducer can increase the performance of precision instruments in the closed mechanical relationship. Calibration is the key to ensure the pressure transducer with a high precision and dynamic characteristic. Unfortunately, the current calibration method can usually be used in the laboratory with a good condition and only one pressure transducer can be calibrated at each time. Therefore the calibration efficiency is hard to meet the requirement of modern industry with high efficiency. A dynamic and fast calibration technology with a calibration device and a corresponding data processing method is proposed in this paper. Firstly, the pressure transducer to be calibrated is placed in the small cavity chamber. The calibration process only contains a single loop. The outputs of each calibrated transducer are recorded automatically by the control terminal. Secondly, LabView programming is used for the information acquisition and data processing. The performance of the repeatability and nonlinear indicators can be figured out directly. At last the pressure transducers are calibrated simultaneously in the experiment to verify the suggested calibration technology. The experimental result shows this method can be used to calibrate the pressure transducer in the practical engineering measurement.

The signal quality of traveling wave and the measurement accuracy of parasitic time grating can be improved by optimiz ing its structure. This optimization process can be guided through building the electrical traveling wave equation with respect to the structure and the traveling wave signal generation principle. Based on Ansoft Maxwell simulation, the important electromagnetic parameters and the main uncertainty sources were analyzed and determined respectively. In the simulation parameters such as the excitation signal frequency, the gap width, the relative area of the probe, the coils number, the excitation signal amplitude and the core length were set to different values. It can be seen from the simulation results that excitation signal frequency, the gap width, the relative area between the probe and the rotor are the major factors to influence the angular measuring accuracy of parasitic time grating sensor. Meanwhile, the coils number, the excitation signal amplitude and the core length are the secondary factors. The analysis result can be utilized to optimize the structure of parasitic time grating and correct measurement error.

At National Institute of Metrology, China (NIM), a portable and real-time self-calibration angle encoder was developed to meet the requirement of angular measurement with high accuracy, high speed, and high adaptability in limited size. In the development, the special arrangement of reading heads, the structure of bearing was designed base on the novel selfcalibration method, and the corresponding signal acquisition and processing system was set up with capability of high speed and multi-channel synchronous data acquisition and processing. The max rotary speed of this angle encoder gets 18 r/min (110°/s) in real-time mode. This angle encoder was compared with NIM’s primary angle standard. The calibration result shows that this angle encoder has angle measuring accuracy better than ±4″.

The grating projection measurement method has broad applications in surface 3D topography measuring due to its measurement speed and accuracy. Along with the grating, the phase-shift method is usually adopted for calculating the field phase. This is achieved by projection scanning in order to obtain more grating fringe images. The higher the projection fringe density is, the higher resolution can be achieved. However, because the results of the projected grey value periodically change, once the fringe period is over the single-period, the absolute-phase will become wrapped-phase. Always obtain the absolute phase by means of an unwrapping algorithm because the traditional projection unwrapping algorithm, which is based on phase continuity and changing conditions, it is not suitable for step-height measuring. Aiming to solve this problem, an unusual sub-step projection scanning method for variable widths of grating periods is proposed. According to the principle of minimum error, using the step-by-step phase estimation and connection method, we can directly determine the high-density fringe projection absolute-phase.

This paper presents the intrinsic fluorescence characteristics of vitamin B1, B2 and B6 measured with 3D fluorescence Spectrophotometer. Three strong fluorescence areas of vitamin B2 locate at λex/λem=270/525nm, 370/525nm and 450/525nm, one fluorescence areas of vitamin B1 locates at λex/λem=370/460nm, two fluorescence areas of vitamin B6 locate at λex/λem=250/370nm and 325/370nm were found. The influence of pH of solution to the fluorescence profile was also discussed. Using the PARAFAC algorithm, 10 vitamin B1, B2 and B6 mixed solutions were successfully decomposed, and the emission profiles, excitation profiles, central wavelengths and the concentration of the three components were retrieved precisely through about 5 iteration times.

Based on the relative theories of quality resource management system and “Internet +”, this paper combines the “Internet +”and quality resource management system. By using quality management process approach and taking computers and databases technology as tools, the system collects, archives and manages the quality data in process network, to supervise and control the process of the quality resource management system more effectively. Based on the quality control process in production site and the characteristics of the process, the paper constructs the frame of the resource management system. By taking the STM32F103 series microcontroller as core controller, the system achieves a network system and collects data automatically. The results show that the system can be positioning problem accurately timely and improves the productivity and quality of products.

In order to realize online real-time monitoring of the hydraulic bracket support, improve the existing communication system, and improve the reliability of data transmission, this paper set up the communication simulation system and platform to simulate the coal mine communication based CAN bus. Based on the design and analysis of system hardware and software, this paper completed the construction of the whole hardware and the debugging of communication system. The debug end can communicate simulate by the CAN protocol simulation device, and realized the work of the entire communication system. Experiments showed that the monitoring system can work reliably.

Based on dean-flow-coupled elasto-inertial effects, 3D particle focusing in a straight channel with asymmetrical expansion–contraction cavity arrays (ECCA channel) is achieved. First, the mechanism of particle focusing in both Newtonian and non-Newtonian fluids was introduced. Then particle focusing was demonstrated experimentally in this channel with Newtonian and non-Newtonian fluids using three different sized particles (3.2μm, 4.8 μm, 13 μm), respectively. The influences of flow rates on focusing performance in ECCA channel were studied. Results show that in ECCA channel particles are focused on the cavity side in Newtonian fluid due to the synthesis effects of inertial and dean-drag force, whereas on the opposite cavity side in non-Newtonian fluid due to the addition of viscoelastic force. Compared with the focusing performance in Newtonian fluid, the particles are more easily and better focused in non- Newtonian fluid. A further advantage is three-dimensional (3D) particle focusing in non-Newtonian fluid is realized according to the lateral side view of the channel while only two-dimensional (2D) particle focusing can be achieved in Newtonian fluid. Conclusively, this Dean-flow-coupled elasto-inertial microfluidic device could offer a continuous, sheathless, and high throughput (>10000 s^-1) 3D focusing performance, which may be valuable in various applications from high speed flow cytometry to cell counting, sorting, and analysis.

With respect to orifice throttling or compensating, capillary throttling has following advantages: smaller mass flow rate and stronger anti-interference ability. This paper firstly gives the required average pressure of air-film when shipping a piece of LCD glass. Then, dimensional flow model of the capillary throttling of air-flotation unit is established. Based on the model, we firstly analyze the flowing process of the lubricated air through the capillary. Secondly, the pressure distribution equation of air-film is derived from the Navier−Stokes Equation. Furthermore, the approximate functional relations between model parameters and static characteristics of the air-film, such as mass flow rate, static bearing capacity, are obtained and then influence of the former on the latter is analyzed . Finally, according to the continuity of air flow, the function relation between model parameters and pressure of core nodes in the air-film is also derived. On foundation of theoretical analysis, the impacts of each model parameter on static characteristics of the air-film flow field, are respectively simulated and analyzed by CFD software Fluent. Based on these simulations and analysis, radius and length of the capillary, density of the gas supply orifices and other model parameters are optimized. Finally, the best unit model is acquired, which greatly improves the static working performance of air-film in air-flotation unit. Research results of this paper can provide guidance and basis for the design and optimization of air-flotation transporting system.

The calibration of acoustic emission sensor is important for acoustic emission quantitative evaluation. To carry out the sensor calibration, one way is to find a reference acoustic emission source, such as a falling solid ball, a fracturing pencil lead, with energy evaluation to obtain the characteristics of the reference source. One way is to use a reference sensor to measure the pressure or the normal velocity at the surface, including the capacitive transducer and the laser interferometer. The other is using reciprocity method. Frequency characteristics of amplitude of absolute sensitivity of both the Rayleigh and longitudinal waves could be determined by purely electrical measurement without the use of mechanical sound sources of reference transducers. In this paper, the progress of the methods of the AE sensor calibration was given. The principles and the merits and faults of each method are discussed. In this paper the rapid calibration method by pulse exciting transducer was also discussed in different wave mode, as well as Face to Face method.

Glass hydrometers are simple but effective instruments for measuring the density of liquids. Glass hydrometers calibration based on the Archimedes law, using silicon ring as a reference standard solid density, n-tridecane with density stability and low surface tension as the standard working liquid, based on hydrostatic weighing method designs a glass hydrometer calibration system. Glass hydrometer calibration system uses CCD image measurement system to align the scale of hydrometer and liquid surface, with positioning accuracy of 0.01 mm. Surface tension of the working liquid is measured by Whihemy plate. According to twice glass hydrometer weighing in the air and liquid can calculate the correction value of the current scale. In order to verify the validity of the principle of the hydrostatic weighing method of glass hydrometer calibration system, for measuring the density range of (770-790) kg/m³, with a resolution of 0.2 kg/m³ of hydrometer. The results of measurement compare with the Physikalisch-Technische Bundesanstalt(PTB) ,verifying the validity of the calibration system.

A parallel common path phase-shifting interferometer is presented using a digital reflective grating realized by a digital micromirror device (DMD). The interferometer based on a modified Michelson architecture is constructed by a beamsplitter, a pinhole mirror, a digital reflective Ronchi grating and two lenses with same focal length to build a 4f optical system. In the interferometer, the pinhole mirror is used to low-filter the input-beam to act as reference beam, and the grating is used to introduce phase shift among +1, 0, and −1 diffraction orders of the input-beam to act as object beam. Then the specimen phase can be reconstructed from the three phase-shifted interferograms recorded in one shot using a normalize algorithm. The theoretical analysis and experiments are carried out to demonstrate the feasibility and accuracy of the proposed method.

As a typical comprehensive error measurement method, the double-ball-bar (DBB) has been invented and used widely for evaluating and diagnosing the accuracy of NC machine tools. However, due to the expansion length of DBB’s bar is very limited, the working efficiency of the DBB is greatly reduced and different length bars are mostly used to realize different measurement ranges. In this paper, a novel DBB with two spatial linkages and one spherical joint was presented to implement a wide detection range and simplify the operation. The structure of the proposed device was firstly introduced. The working principle of the device was then described, and the mathematical model for detecting machine’s accuracy was also built. According to the angle of spatial linkages and lengths of two bars, circular motions trajectory which is caused by interpolation movement of two shafts can be calculated and compared with theoretical value to evaluate machine tool’s accuracy. Finally, the simulation was done to validate the feasibility of the proposed device. The results show that the proposed DBB has reasonable structures. Moreover, the measuring range can cover a large region of space and it is continuous.

In lithography process, the precision of wafer pattern to a large extent depends on the geometric dimensioning and tolerance of photomasks when accuracy of lithography aligner is certain. Since the minimum linewidth (Critical Dimension) of the aligner exposing shrinks to a few tens of nanometers in size, one-tenth of tolerance errors in fabrication may lead to microchip function failure, so it is very important to calibrate these errors of photomasks. Among different error measurement instruments, deep ultraviolent (DUV) microscope because of its high resolution, as well as its advantages compared to scanning probe microscope restrained by measuring range and scanning electron microscope restrained by vacuum environment, makes itself the most suitable apparatus. But currently there is very few DUV microscope adopting 248nm optical system, means it can attain 80nm resolution; furthermore, there is almost no DUV microscope possessing traceable calibration capability. For these reason, the National Institute of Metrology, China is developing a metrological 248nm DUV microscope mainly consists of DUV microscopic components, PZT and air supporting stages as well as interferometer calibration framework. In DUV microscopic component, the Köhler high aperture transmit condenser, DUV splitting optical elements and PMT pinhole scanning elements are built. In PZT and air supporting stages, a novel PZT actuating flexural hinge stage nested separate X, Y direction kinematics and a friction wheel driving long range air supporting stage are researched. In interferometer framework, a heterodyne multi-pass interferometer measures XY axis translation and Z axis rotation through Zerodur mirror mounted on stage. It is expected the apparatus has the capability to calibrate one dimensional linewidths and two dimensional pitches ranging from 200nm to 50μm with expanded uncertainty below 20nm.

With the wide development of injection molding process, the embedded monitoring system based on machine vision has been developed to automatically monitoring abnormality of injection molding processing. First, the construction of hardware system and embedded software system were designed. Then camera calibration was carried on to establish the accurate model of the camera to correct distortion. Next the segmentation algorithm was applied to extract the monitored objects of the injection molding process system. The realization procedure of system included the initialization, process monitoring and product detail detection. Finally the experiment results were analyzed including the detection rate of kinds of the abnormality. The system could realize the multi-zone monitoring and product detail detection of injection molding process with high accuracy and good stability.

The condition detection of wind turbine is always an important issue which attract more and more attentions because of the rapid development of wind farm. And the on-line data analysis is also difficult since a lot of measured data is collected.

In this paper, the abnormal data rejection and normal condition evaluation of wind turbine is processed. At first, since there are large amounts of abnormal data in the normal operation of wind turbine, which is probably caused by fault, maintenance downtime, power-limited operation and failure of wind speed sensor, a novel method is proposed to reject abnormal data in order to make more accurate analysis for the wind turbine condition. The core principle of this method is to fit the wind power curves by using the scatter diagram. The data outside the area covered by wind power curves is the abnormal data. The calculation shows that the abnormal data is rejected effectively. After the rejection, the vibration signals of wind turbine bearing which is a critical component are analyzed and the relationship between the vibration characteristic value and the operating condition of wind turbine is discussed. It will provide powerful support for the accurate fault analysis of wind turbine.

In order to improve the engine vibration signal process method for the engine cylinder pressure and engine revolution speed measurement instrument, the engine cylinder pressure varying with the engine working cycle process has been regarded as the main exciting force for the engine block forced vibration. The forced vibration caused by the engine cylinder pressure presents as a low frequency waveform which varies with the cylinder pressure synchronously and steadily in time domain and presents as low frequency high energy discrete humorous spectrum lines in frequency domain. The engine cylinder pressure and the rotation speed can been extract form the measured engine block vibration signal by low-pass filtering analysis in time domain or by FFT analysis in frequency domain, the low-pass filtering analysis in time domain is not only suitable for the engine in uniform revolution condition but also suitable for the engine in uneven revolution condition. That provides a practical and convenient way to design motor revolution rate and cylinder pressure measurement instrument.

The wavelength of laser interferometer used widely in precision measurement instrument is affected by the refractive index of surrounding air, which depends on the temperature, relative humidity (RH) and air pressure. A low-cost mini chamber based on the natural convection principle with high-precision temperature-controlled and humidity-suppressed is proposed in this paper. The main chamber is built up by acrylic walls supported by aluminum beam column and are tailored according to the required space. A thin layer of vacuum insulation panel (VIP) with an ultralow thermal conductivity coefficient is adhered around the walls so as to prevent heat exchange with room air. A high-precision temperature sensor measuring the temperature near the instrument’s measuring point provides a feedback signal to a proportional-integral-derivative (PID) controller. Several thermoelectric coolers uniformly arranged on the ceiling of the chamber to cool the air inside the chamber directly without any air supply system, yielding a vibration-free cooling system. A programmable power supply is used as the driver for the coolers to generate different cooling capacities. The down-flowing cool air and the up-flowing hot air form a natural convection, and the air temperature in the chamber gradually becomes stable and finally reaches the temperature set by the PID controller. Recycled desiccant contained silica gels that have high affinity for water is used as a drying agent. Experimental results show that in about two hours the system’s steady state error is 0.003°C on average, and the variation range is less than ± 0.02°C when the set temperature is 20°C, the RH is reduced from 66% to about 48%. This innovative mini chamber has the advantages of low-cost, vibration-free, and low energy-consumption. It can be used for any micro/nanomeasurement instrument and its volume can be customer-designed.

As the main electrical component for the reactive power compensation, the power capacitors are widely applied in many fields. And since the insulation condition of power capacitor could be identified accurately by using the on-line monitoring system, it attracts more and more attentions in recent years.

In this paper, a novel on-line monitoring equipment for power capacitor based on wireless sensor network is presented. The operation data which includes the current and voltage of every capacitor is collected at first, and then the FFT is utilized to calculate the amplitude and phase of every signal, thus the insulation condition and the fault symptom could all be diagnosed accurately by analyzing the FFT results. In order to realize the effective isolation and the reliable communication between the sensing part and the merging unit, the wireless sensor network is adopted. The high reliability and transmission rate could be realized by using 2.4GHz UHF and 5GHz ISM radio bands. Thus the on-line monitoring system could be manufactured, and the lab test is carried at last. The testing results illustrate that this system could satisfy the requirement of on-site real-time measurement.

To film the moving fish in the glass tank, light will be bent at the interface of air and glass, glass and water. Based on binocular stereo vision and refraction principle, we establish a mathematical model of 3D image correlation to reconstruct the 3D coordinates of samples in the water. Marking speckle in fish surface, a series of real-time speckle images of swimming fish will be obtained by two high-speed cameras, and instantaneous 3D shape, strain, displacement etc. of fish will be reconstructed.

The installation verticality between the optical axis of CCD and the working plane of intelligent laser cutting machine is one of the most important factors in determining image quality of the processed object which comes from computer vision system. In this paper, an innovative method is proposed which can make it possible to use the equipment of own system of intelligent laser cutting machine to detect installation verticality between the optical axis of CCD and the working plane. Experimental results show that the method presented in this paper is a feasible solution for measuring the installation verticality between the optical axis of CCD and the working plane of intelligent laser cutting machine.

Online analytical instruments have been increasingly widely applied to various kinds of industrial facilities. And the Raman spectrum analyzer is one of the typical representatives, which has been widely used in chemical,environment, biological, medical, court and identification science, geology, material, oil and other fields of study. With the rapid development of Chinese economy and sharp increase in demand of fossil fuels, it’s crucial to figure out how to measure the intensity of Raman spectra in high precision and how to use the Raman spectra to acquire the high precision result of each component in natural gas. Therefore, how to process the natural gas Raman spectra’s base has become one of a vital and indispensable steps. So this paper proposes a new method to acquire the base which based on the designed Raman spectrometer structure system. The designed laser Raman gas analysis system shown as the following figure 1. The method of real-time difference which has been used to eliminate the background noise of basement can be fulfilled by adjusting the black baffle position up or down. By this way, intensity of gas signal spectra can be obtained. Compared to the method of using argon basal calibration, the hardware operation to preprocess the basement is more simple, and what just need to do is to adjust the electromagnetic valve to control the upper and lower position of the panel. It has important practical application value for saving cost and implementing easily.

Giant magnetostrictive material (GMM) is an attractive material for sensors because of its characteristics including high relative permeability and high magneto-mechanical coupling coefficient. Based on the Villari effect and crystal anisotropy theory of this material, the mathematical models which describe the relation between GMM rod permeability and its pressure, the relation between induction coil inductance and its relative permeability were established in this paper. The models were simulated and analyzed by using MATLAB software. The results show that there is a good linear relationship between the pressure exerted on the GMM rod and the inductance of induction coil, which lays a theoretical basis to design a three-dimensional force sensor with high precision, high stability and good output characteristics.

This investigation applied the digital image correlation technique (DIC) on a pressure vessel that contained several surface pit defects under high pressure. Data on the deformation of the defects and peripheral area is obtained by this method. The results show that the stress and strain increase with the depth among different pits and are the largest at the bottom of any given pit. This method has proven to be a good choice for this type of experiment, where elastic and plastic surface strains need to be measured. The DIC can satisfy the requirements of being in situ, in real time, full-field and make non-contact measurements with more accurate and obvious experimental results compared with traditional measurement methods and pressure vessel test regulations. Also, it is a new, effective way for monitoring defects in online pressure vessels as well as a reliable basis for pressure vessels’ safety evaluation.

In this article, a blade synchronous vibration measurement method based on tip-timing at constant rotating speed is presented. This method requires no once-per revolution sensor, which makes it more generally applicable, especially for high pressure compressors of the dual rotor engines. The vibration amplitude and engine order are identified with this method. The theoretical analysis is presented, and the least square method is utilized for vibration parameter identification. The method requires at least four tip-timing sensors if the Campbell diagram is previously known and five sensors if the Campbell diagram is unknown. The method has no strict requirement on the angles among sensors which facilitate the installation of the sensors in the measurement. In some special conditions the method will fail and these conditions are analyzed. Experiments are conducted on a high speed rotor with a fiber based tip-timing system, and the experimental results indicate that the theoretical analysis is correct and the method is feasible.

The contact position’s accurate measurement is the key part of the realization of high voltage switchgear’s on-line monitoring. Based on the position measurement, the speed and trip of the switchgear could also be obtained. Thus, the health level and the operation status can be evaluated. The insulation condition and the fault symptom can also be identified. In this paper, the on-line measuring principle for the contact position is presented at first. The indirect measuring method is adopted, and the incremental photoelectric encoder is utilized to realize the measurement of angular displacement. The position could be calculated by establishing the relationship between the angular displacement and the contact’s linear displacement. After that, the technical difficulties of the on-line measuring system are demonstrated. The selection of encoder, the difficult parts of hardware design and software design are all discussed deeply. The lab test of the whole measuring system is processed at last, and the measuring results are satisfactory. It will provide powerful support for the realization of on-line monitoring equipment of the high voltage switchgear.

Due to high-precision, self-cleaning, anti-interference, non-contact and the other advantages, pneumatic measuring has been widely used in the high-precision, non-contact measurement. Traditional back-pressure measurement had been used in ever cases, but with small measuring range (200μm), its application is limited. While reflection-type pneumatic sensor can be used for online, non-contact measurement, and with large measuring rang (4~5mm) and high-precision (5~10μm), it may also be applied to the sensor calibration. But structural design of its measuring head has a huge impact on the range and accuracy of the sensor. In this paper, the operation principle of a new large range non-contact dimension measuring device is introduce, based on hydrodynamics, a finite element model of the measuring head is systematically constructed, by using finite element simulation software, the influence of sensitivity and linear rang from multiple structural parameters and flow parameters would be analyzed. Through simulation results under different parameters, we obtained optimal geometrical parameters of reflection-type pneumatic head, so as to achieve the purpose of optimizing the design of reflection-type pneumatic head. From the simulation results, the characteristic curve after optimization has good linearity and large measurement range.

Traditional matching algorithms cannot be directly applied to the fisheye image matching for large distortion existing in fisheye image. Therefore, a matching algorithm based on uncorrected fisheye images is proposed. This algorithm adopts a local feature description method which combines MSER detector with CSLBP descriptor to obtain the image feature. First, the two uncorrected fisheye images captured by binocular vision system are described by the principle of epipolar constraint. Then the region detection is done with MSER and the ellipse fitting is used to the obtained regions. The MSER regions are described by CSLBP subsequently. Finally, in order to exclude the mismatching points of initial match, random sample consensus (RANSAC) algorithm has been adopted to achieve exact match. Experiments show that the method has a good effect on the uncorrected fisheye image matching.

A method of error separation on the principle of multiple signal superposition is introduced for time grating angular displacement sensors. According to the theory of error compensation, the accuracy of time grating sensors can be improved by compensating the separated errors. Errors of time grating angular displacement sensors caused by stators and rotors during manufacturing are separated and majority long-periodic and short-periodic errors are removed using this method. Thus, error compensation model can be established for these separated errors using the method of harmonic analysis. Circular indexing errors caused by slots of stators and rotors of time grating sensors can be compensated using this model. The accuracy is improved significantly to a field-type time grating by the error compensation model. The precise is 2.8″ after calibrating. Experiments prove that the method of error separation is very effective for removing indexing errors and the established error compensation model shows obvious effect in calibrating errors of time grating angular displacement sensors.

Along with the rapid development of the science and technology in fields such as space optics, multi-scale enriched freeform surfaces are widely used to enhance the performance of the optical systems in both functionality and size reduction. Multi-sensor technology is considered as one of the promising methods to measure and characterize these surfaces at multiple scales. This paper presents a multi-sensor data fusion based measurement method to purposely extract the geometric information of the components with different scales which is used to establish a holistic geometry of the surface via data fusion. To address the key problems of multi-sensor data fusion, an intrinsic feature pattern based surface registration method is developed to transform the measured datasets to a common coordinate frame. Gaussian zero-order regression filter is then used to separate each measured data in different scales, and the datasets are fused based on an edge intensity data fusion algorithm within the same wavelength. The fused data at different scales is then merged to form a new surface with holistic multiscale information. Experimental study is presented to verify the effectiveness of the proposed method.

In the present application of Coordinate Measuring Machines (CMMs), generally only the estimated value of the measured quantity can be computed while its corresponding measurement uncertainty can not. It is well known that a result without its uncertainty is incomplete. However, uncertainty evaluation has always been one difficult issue in application of CMM because error sources causing measurement uncertainty of CMM are very complex. Based on Geometrical Product Specifications (GPS), the three measurement strategies of CMM application, i.e. conventional measurement, substitution measurement and compensation measurement strategies, are studied in this paper. For each measurement strategy, the uncertainty sources are analyzed, and the corresponding task-oriented uncertainty evaluation model is established. In this paper, the hole diameter measurement of one workpiece is taken as an example. The uncertainty is evaluated respectively according to the three different strategies, and the results are compared. The comparison result shows that the influence of different measurement strategy on measurement result is different, the maximum difference is about 2 times, and the accuracy of measurement can be improved through selecting proper measurement strategy for specific measurement task.

All-day star sensor makes it possible to observe stars in all-day time in the atmosphere. But the detecting performance is influenced by atmospheric turbulence. According to the characteristic of turbulence in long-exposure model, the modulation transfer function, point spread function and encircled power of the imaging system have been analyzed. Combined with typical star sensor optical system, the signal to noise ratio and the detectable stellar magnitude limit affected by turbulence have been calculated. The result shows the ratio of aperture diameter to atmospheric coherence length is main basis for the evaluation of the impact of turbulence. In condition of medium turbulence in day time, signal to noise ratio of the star sensor with diameter 120mm will drop about 4dB at most in typical work environment, and the detectable stellar limit will drop 1 magnitude.

With the development of science and technology, field emission scanning electron microscope (FESEM) plays an important role in nano-material measurements because of its advantages of high magnification, high resolution and easy operation. A high-quality secondary electron image is a significant prerequisite for accurate and precise length measurements. In order to obtain high-quality secondary electron images, the conventional treatment method for non-conductive materials is coating conductive films with gold, carbon or platinum to reduce charging effects, but this method will cover real micro structures of materials, change the sample composition properties and meanwhile introduce a relatively big error to nano-scale microstructure measurements. This paper discusses how to reduce or eliminate the impact of charging effects on image quality to the greatest extent by changing working conditions, such as voltage, stage bias, scanning mode and so on without treatment of coating, to obtain real and high-quality microstructure information of materials.

Stochastic resonance as a means of signal detection and enhancement, is always based on the general simple bistable system, this research extends the general one into a new complex fractional order bistable system, which is established on the over-damped fractional Langevin equation, the dynamic characteristic of the new system is analyzed by simulation, the generation and enhancement of stochastic resonance as well as its relation with the internal parameters is studied. The system when applied with weak periodic signal and external noise is also researched, we found that the stochastic resonance phenomenon can be generated and improved by changing the fractional order, frequency of input periodic signal and the external noise, the power spectrum of weak signal being detected is boosted thus making it more easily to be detected.

A circuit processing method is present to restrain DC drift after analyzing the traditional signal processing method of interferometry for micro vibration measurement. At first, the circuit diagram is designed and its mathematical model is built, then the theoretical equations of the output signal are derived with the practical parameters. By using SIMULINK simulation, the process for restraining DC drift is present on the conditions of the variations of background intensity. The validity of feedback circuit was verified through analyzing the real experiment data. Theoretical predictions match simulation results, showing that this method effectively restrains DC drift for interferometry of micro vibration measurement and it greatly improves the system’s stability.

In this paper, air hammer instability of nozzle-floating plate institution in gas lubricated force sensor were studied. Through establishment of the theoretical model for the analysis of the nozzle-floating plate institution stability, combined with air hammer stability judgment theorems, we had some simulation research on the radius of the nozzle, the radius of the pressure chamber, pressure chamber depth, orifice radius and the relationship between air supply pressure and bearing capacity, in order to explore the instability mechanism of nozzle-floating plate institution. For conducting experimental observations for the stability of two groups nozzle-floating plate institution, which have typical structural parameters conducted experimental observations. We set up a special experimental device, verify the correctness of the theoretical study and simulation results. This paper shows that in the nozzle-floating plate institution, increasing the nozzle diameter, reduced pressure chamber radius, reducing the depth of the pressure chamber and increase the supply orifice radius, and other measures is conducive to system stability. Results of this study have important implications for research and design of gas lubricated force sensor.

As regards the problems of using absolute linear time grating sensors as the position detector for full closed-loop CNC system, it is necessary transform temporal information to spatial information with time-space transformation algorithm for absolute linear time grating sensors. Time grating sensor’ signal interpolation model is established with time series. The purpose is to extract the relation mapping between future measurement value and past measurement value. In this way, original absolute displacement signal sampled in equal time interval can be converted to continuous incremental pulses required by full closed-loop CNC system. Furthermore, the predicted error model is proposed to improve the interpolation accuracy. The experiment results prove that the interpolation accuracy can reach 0.65 μm, the resolution can reach 0.1 μm.

To enrich the sensing mechanism of the FBG sensors, the cantilever FBG sensor is taken as an example to analyze the effect of the deflection on the embedded stress distribution and structure parameters of the FBG, and a widely applicable analysis method is thus proposed. Models of the single-core and multi-core FBG sensor are built by the proposed method and a modified transmission matrix method is utilized to simulate the built models. The lateral resolution of the multicore FBG sensor is proved to be 1500 times higher than the single-core FBG sensor. Simulation results of the proposed models indicate that this approach is tally with the experiment of other researches, and it can be used to analyze the performance of the designed sensors, such as spectrum signal and resolution, or as a guide of designing FBG sensors.

Defects exist for a few of IC chips during fabrication and packaging. The cost for follow-up processes can be reduced if chips with defect size of impacting chip quality can be inspected and removed during the earlier sorting process. Products will be more cost-effective and competitive. According to the inspecting requirements for microphone chips, developed AOI system has to detect the boundary flaws and hole-inside defects with size of greater than criteria from chips backside. Both the length and width of chip size are less than 5 mm and there’s depth difference between the surface of chip backside and the hole-inside membrance. Thus image acquisition device is designed and implemented by an area scan imager and a telecentric lenses with a coaxial LED lighting module. Therefore we can ignore the image radiometric and geometric calibration, and keep off the shadow inside the rim of hole. An algorithm to detect defects and derive their size based on the edge pixels statistic distribution and binary chip edge image is selected. Developed AOI system then can meet the requirements of real-time defect inspection with high accuracy and performance.

Frame opto-mechanical device has the spatial resolution of 5μm and FOV of 6.4 x 5.1 mm. And defect inspection can be completed within 150 ms for the chip size of 2.5 x 3.0 mm. The processes of image acquisition and defect inspection can be accomplished during the chip sorting process to satisfy the real-time online inspection. Inspected chips are placed in GO/NG trays in real-time according to their quality. From the verification results compared with the ones by microscope, the inspection accuracy is better than system requirements. The over kill rate is less than 0.3% and 3% for chip boundary flaws and hole-inside defects respectively. But it still can’t be inspected correctly for the hole-inside defects of only one membrance breakage. In the future, we will improve the illumination and detecting algorithm to solve this imperfection. Inspection systems have been integrated into our customer’s chip sorters, and successfully delivered to and accepted by end-users for online operations. Our system also can be accommodated to other customer’s chip sorters with specific requirements for chip backside inspection.

Freeform surfaces are widely used in precision components to realize novel functionalities. In order to evaluate the form qualities of the manufactured freeform parts, surface matching/fitting is required. The uncertainty of the obtained form deviations needs to be estimated to assess the reliability of form error evaluation. The GUM approach is extensively adopted for uncertainty assessment in precision metrology, but it is not suited for assessing the nonlinear matching/fitting problems of freeform models. In this paper a Monte-Carlo method is developed to estimate the uncertainty of the fitted position, shape and form error metrics. Based on the correlation analysis, the effects of objective functions in numerical optimization, noise amplitudes in measurement, shapes of freeform surfaces and so on are determined. Then the significant factors dominating the reliability of the fitted results can be identified. Henceforth the matching/fitting procedures can be arranged appropriately to reduce the uncertainty of the evaluation results and improve the reliability of freeform surface characterization.

To solve the problem of the small field of the view caused by CCD in the process of the hologram record, the hologram mosaic algorithm based on the Harris corners is proposed. The Harris corners in multi-scale are extracted and the mismatching points are removed. The final homography is calculated by using the improved RANSAC algorithm based on L-M algorithm. Finally, the stitched hologram with high quality can be obtained based on the weighted average fusion algorithm. It can overcome the influence to the hologram that the incident angles of the object beam are not consistent. Two experiments carried out with different reconstructed distance demonstrate that the proposed algorithm can realize the measurement of the big object by using the hologram method. Furthermore, it has high accuracy and strong robustness.

A high-resolution transducer of linear displacements is presented. The system is based on semiconductor laser illumination and a diffraction grating applied as a length master. The theory of the optical method is formulated using Doppler description. The relationship model among the interference strips, measurement errors, grating deflection around the X, Y and Z axes and translation along the Z axis is built. The grating interference strips' direction and space is not changed with movement along the X (direction of grating movement), Y (direction of grating line), Z axis, and the direction and space has a great effect when rotating around the X axis. Moreover the space is little affected by deflection around the Z axis however the direction is changed dramatically. In addition, the strips' position shifted rightward or downwards respectively for deflection around the X or Y axis. Because the emitted beams are separated on the grating plane, the tilt around the X axis error of the stage during motion will lead to the optical path difference of the two beams resulting in phase shift. This study investigates the influence of the tilt around the X axis error. Experiments show that after yaw error compensation, the high-resolution diffraction grating interferometric transducer readings can be significantly improved. The error can be reduced from ±80 nm to ±30 nm in maximum.

The technology of multi-scale optical systems could be used to achieve a balance of the field-of-view and F-number, and helpful enhance the system image quality. This paper designed a multi-scale optical lens, and finished the work of demonstrating theoretically the feasibility of curved image together with the array lens. An idea has been proposed in this paper, using the approximately concentric chief rays combining with balance aberrations in each channel of the array lens to alleviate the aberrations of the whole optical system. Lastly, we designed a specific optical path and completed the experimental analysis. Experimental results show that the optical layout of the multi-scale optical lens can achieve a field of view of 60 degree while the aberration balance is well.

DBH(diameter at breast height) is an important factor to reflect of the quality of plant growth, also an important parameter indispensable in forest resources inventory and forest carbon sink, the accurate measurement of DBH or not is directly related to the research of forest resources inventory and forest carbon sink. In this paper, the principle and the mathematical model of DBH measurement device were introduced, the fixture measuring device and the hardware circuit for this tree diameter were designed, the measurement software programs were compiled, and the precision measuring device of tree diameter growth was developed. Some experiments with Australia fir were conducted. Based on experiment data, the correlations among the DBH variation of Australian fir, the environment temperature, air humility and PAR(photosynthetically active radiation) were obtained. The effects of environmental parameters (environment temperature, air humility and PAR) on tree diameter were analyzed. Experimental results show that there is a positive correlation between DBH variation of Australian fir and environment temperature, a negative correlation between DBH variation of Australian fir and air humility , so is PAR.

The absolute distance measurement was experimentally demonstrated by using the fiber femtosecond optical frequency comb in air. The technique is based on the measurement of cross correlation between reference and measurement optical pulses. This method can achieve accuracy better than the commercial laser interferometer. It is attained sub-micrometer resolution in large scale measurement by using the fiber femtosecond optical frequency comb. It will be benefit for future laser lidar and satellite formation flying mission.

In order to realize the space camera which on satellite optical axis pointing precision measurement, a monocular vision measurement system based on object-image conjugate is established. In this system the algorithms such as object-image conjugate vision models and point by point calibration method are applied and have been verified. First, the space camera axis controller projects a laser beam to the standard screen for simulating the space camera’s optical axis. The laser beam form a target point and has been captured by monocular vision camera. Then the two-dimensional coordinates of the target points on the screen are calculated by a new vision measurement model which based on a looking-up and matching table, the table has been generated by object-image conjugate algorithm through point by point calibration. Finally, compare the calculation of coordinates offered by measurement system with the theory of coordinate offered by optical axis controller, the optical axis pointing precision can be evaluated. Experimental results indicate that the absolute precision of measurement system up to 0.15mm in 2m×2m FOV. This measurement system overcome the nonlinear distortion near the edge of the FOV and can meet the requirement of space camera’s optical axis high precision measurement and evaluation.

An automatic flatness detection system for micro rings is developed. It is made up of machine vision module, ring supporting module and control system. An industry CCD camera with the resolution of 1628×1236 pixel, a telecentric with magnification of two, and light sources are used to collect the vision information. A rotary stage with a polished silicon wafer is used to support the ring. The silicon wafer provides a mirror image and doubles the gap caused by unevenness of the ring. The control system comprise an industry computer and software written in LabVIEW Get Kernel and Convolute Function are selected to reduce noise and distortion, Laplacian Operator is used to sharp the image, and IMAQ Threshold function is used to separate the target object from the background. Based on this software, system repeating precision is 2.19 μm, less than one pixel. The designed detection system can easily identify the ring warpage larger than 5 μm, and if the warpage is less than 25 μm, it can be used in ring assembly and satisfied the final positionary and perpendicularity error requirement of the component.

The precision of the calibration factor of a superconducting gravimeter (SG) using an absolute gravimeter (AG) is analyzed based on linear least square fitting and error propagation theory and factors affecting the accuracy are discussed. It can improve the accuracy to choose the observation period of solid tide as a significant change or increase the calibration time. Simulation is carried out based on synthetic gravity tides calculated with T-soft at observed site from Aug. 14th to Sept. 2nd in 2014. The result indicates that the highest precision using half a day’s observation data is below 0.28% and the precision exponentially increases with the increase of peak-to-peak gravity change. The comparison of results obtained from the same observation time indicated that using properly selected observation data has more beneficial on the improvement of precision. Finally, the calibration experiment of the SG iGrav-012 is introduced and the calibration factor is determined for the first time using AG FG5X-249. With 2.5 days’ data properly selected from solid tide period with large tidal amplitude, the determined calibration factor of iGrav-012 is (-92.54423±0.13616) μGal/V (1μGal=10^-8m/s²), with the relative accuracy of about 0.15%.

With the rapid development of aviation and aerospace, the demand for metal coating parts such as antenna reflector, eddy-current sensor and signal transmitter, etc. is more and more urgent. Such parts with varied feature dimensions, complex three-dimensional structures, and high geometric accuracy are generally fabricated by the combination of different manufacturing technology. However, it is difficult to ensure the machining precision because of the connection error between different processing methods. Therefore, a precise positioning method is proposed based on binocular micro stereo vision in this paper. Firstly, a novel and efficient camera calibration method for stereoscopic microscope is presented to solve the problems of narrow view field, small depth of focus and too many nonlinear distortions. Secondly, the extraction algorithms for law curve and free curve are given, and the spatial position relationship between the micro vision system and the machining system is determined accurately. Thirdly, a precise positioning system based on micro stereovision is set up and then embedded in a CNC machining experiment platform. Finally, the verification experiment of the positioning accuracy is conducted and the experimental results indicated that the average errors of the proposed method in the X and Y directions are 2.250 μm and 1.777 μm, respectively.

When a working cylinder of the pressing machine working cylinder was stuck and underwent retracted conversion, pressure shock was high in working cylinder cavity and flow pulsation was distinct in the pipeline due to the high working pressure and frequent retracted transformation of the working cylinder, which not only shortened the service life of the pressing machine, but also exerted serious impacts on the machining precision and quality, especially after the pressing machine applied loads and high-pressure oil in work rod end cavity of working cylinder needed to be relieved in a short time. In order to research and analyze the better pressure relief characteristics of the two types of pressure relief circuits of the pressing machine, the paper established models, carried out simulation and analysis and then made contrastive analysis of the working cylinder rod velocity, rod acceleration and port pressure pulsation according to the simulation results.

Accurate measurement of sound speed is important to calibrate a sound velocity profiler which provides real-time sound velocity to the sonar equipment in oceanographic survey. The sound velocity profiler calculates the sound speed by measuring the time-of-flight of a 1 MHz single acoustic pulse to travel over about 300 mm path. A standard sound velocimeter instrument was invited to calibrate the sound velocity profiler in pure water at temperatures of 278,283, 288, 293, 298, 303 and 308K in a thermostatic vessel at one atmosphere. The sound velocity profiler was deployed in the thermostatic vessel alongside the standard sound velocimeter instrument and two platinum resistance thermometers (PRT) which were calibrated to 0.002k by comparison with a standard PRT. Time of flight circuit board was used to measure the time-of-flight to 22 picosecond precision. The sound speed which was measured by the sound velocity profiler was compared to the standard sound speed calculated by UNESCO to give the laboratory calibration coefficients and was demonstrated agreement with CTD-derived sound speed using Del Grosso's seawater equation after removing a bias.

This paper presents a novel impact piezoelectric linear-rotary motor which is driven by a single piezoceramic tube with two parts of electrodes. From the inner and outer electrodes, longitudinal displacement of the tube is generated and used to actuate the shaft with linear motion ability. From the grooved helical interdigitated electrodes, torsional displacement is generated and used to actuate the shaft with rotary motion ability. Working principle and structural design of the motor are introduced and quasi-static longitudinal and torsional displacements of the tube are estimated. With established kinematics model of the motor, the working behaviors of the motor are investigated numerically with MATLAB/Simulink software. The stepping characteristics of the linear and rotary motions are analyzed, compared, and discussed. With optimized material selection, structural design, and driving parameters, the proposed linear-rotary motor will provide remarkable performances as a miniaturized multi-degree driving device for complex positioning and manipulation applications.

The power transformer is the key equipment of the power system; its insulation condition will directly influence the security and reliability of the power system. Thus, the on-line monitoring of power transformer is urgently required in order to guarantee the normal operation of the power system. Moreover, the dielectric loss factor is a significant parameter reflecting the condition of transformer bushing, so the on-line measurement of dielectric loss factor is really important. In this paper, the phase-to-phase comparison method is selected as the on-line monitoring method based on the overall analysis and discussion of the existing on-line monitoring methods. At first, the harmonic analysis method is utilized to calculate the dielectric loss of each phase of the three-phase transformer bushing, and then the differences of dielectric loss between every two phases are calculated and analyzed. So the insulation condition of each bushing could be achieved based on the careful analysis of different phase-to-phase dielectric loss. The simulation results of phase-to-phase comparison method are carried out in this paper, and the validity is verified. At last, this method is utilized in an actual equipment of on-line monitoring.

This study presents the electromechanical response of a piezoelectric laminated micro plate under the excitation of an ultrasonic wave. The laminated plate consists of a piezoelectric layer (AlN), an elastic layer (SiO₂) and two electrode layers (Au and Pt). Since the whole thickness of the plate is in micro scale, the size dependence of the dynamic behavior of the laminated plate is evaluated using the couple stress theory. The results show that the bending rigidity of the micro plate increases when the size effect is considered and the amplitudes of output of electric charge and voltage are reduced accordingly when the plate is excited by ultrasonic wave. Also the resonant frequency of the laminated plate increase because of the enhancement of the bending rigidity of the plate. The analysis results can provide a reference for the design of micromachined piezoelectric sensors.

Differential box-counting (DBC) method has been widely used to calculate fractal dimension. analyzing the result of fractal dimension with background image by estimating this traditional method,we find that this algorithm has the limitation to estimate fractal dimension of images with background accurately. In order to solve this issue ,in this paper, an improved differential box-counting(IDBC) method has been proposed to eliminate influence of background on fractal dimension .The mainly improved steps of IDBC as follow: firstly ,the background pixels values G_b of image need to be found out using probability .Secondly, the n_q ( n_q is the numbers of boxes in a grid) is set to zero when the maximum and minimum in a grid are equal to image background values. To validate IDBC method’s performance ,we designed an experiment that the fractal dimension of both original texture images and these ones put in different size frame with black-background are estimated and compared through four different algorithms, including DBC, relevant differential box-counting (RDBC) method, shifting differential box-counting (SDBC) method and IDBC method. The experimental results demonstrate that the IDBC method developed in this work has the ability to improve the measurement accuracy by avoiding the influence caused by background.

An active ultra-low frequency vertical vibration isolator is presented in this paper, which could isolate the vibration from the earth. It could create an inertial reference point for precision physics research and experiments such as high precision absolute gravity measurement. This system is based on a structure with two-stage vertical suspension springs. For the second-stage spring, the suspension point is forced to track the suspended mass through closed loop control, and the length of the spring is almost constant and the restoring force of the mass is closed to zero. Consequently, a system with an ultra-low frequency is realized. With precision mechanical design, high resolution photoelectric detection method, and analog circuit feedback control, a vertical vibration isolation system has been constructed with a period of up to about 40s. This vibration isolator meets the demand of high precision absolute gravity measurement and is promisingly applied to the homemade T-1 absolute gravimeter.

The articulated arm coordinate measuring machine (AACMM) is a new type of non-orthogonal coordinate measuring machine (CMM). Unlike the traditional orthogonal CMM which has three linear guides the AACMM is composed of a series of linkages connected by rotating joints. Firstly, the coordinate systems of the AACMM are established according to D-H method, the homogeneous transformation matrixes from the probe to the base of the AACMM are derived. And the graphic simulation system of the AACMM is built in Matlab, which verify the magnitude and direction of the joint angles qualitatively. Then, the data acquisition software of the AACMM is compiled by Visual C++, and there is a statistical analysis on the calculated measuring coordinates and actual coordinates, which indicates that the kinematic model of the AACMM is correct. The kinematic model provides a basis for measurement, calibration and error compensation of the AACMM.

The posture and size of workpiece in pixel level can be determined through optimization of the internal parameters of the camera, utilizing the enclosing rectangle method based on rotation axis to position the workpiece. After selecting ROI of the object, the sub-pixel edge of workpiece is extracted using the bilinear interpolation algorithm and Hessian paradigm line fitting is utilized to find the object edge accurately. The industrial camera with 5 million pixels is used, and the sizes from 80mm to 150mm of the workpiece are measured under the condition of panorama shooting, with measurement repeatability reaching 0.015mm.

The influences of pulse, including the pulse width T_p and the peak pulse power I_peak, on phase-sensitivity optical time domain reflectometer (φ-OTDR) based distributed vibration sensor are investigated in this paper. A numerical simulation is performed to illustrate the relationships between pulse and fluctuations ratio coefficient (FRC) as well as visibility of interferential Rayleigh backscattering light. The simulation results show that the method of amplifying I_peak is benefit for increasing the FRC induced by vibration, while it is useless for improving the visibility. In contrast, the method of broadening T_p is useful for increasing the FRC by improving the visibility. Laboratory experiments are implemented by using the φ-OTDR prototype with an electro-dynamic vibration table producing stable vibration signals. The good agreement of experimental with simulated results validates the theoretical analysis.

In view of the faults of traditional method, a computer vision-based swing center testing method for flexible joint was presented. The first step is to obtain original measurement date by a single industrial camera continuously capturing images of two circular marks which were fixed in the swinging object. The second step is to achieve stable and accurate multi-feature extraction in complex environment by a circular feature extraction method presented by our research group. And the final step is to obtain test results through the markers center coordinate and the swing center computing model. The experimental results indicate that the peak value (PV) error of this method is 1.6mm. This method is effective and it is better than traditional testing methods.

In view of the problems of inflexible saving and calling data and low reliability and being difficult to compatiable with other system for domestic stage video monitoring system, the authors proposed a video supervision and scheduling system of stage based on IP camera. Audio and video technology, multimedia technology and computer network technology were used in the stage video surveillance and scheduling system. The structure of the system were designed and the main functions of the system were tested. The results show that this system can satisfy the modern stage performance effect and monitoring requirements.

PID control is the most common used method in industrial control because its structure is simple and it is easy to implement. PID controller has good control effect, now it has been widely used. However, PID method has a few limitations. The overshoot of the PID controller is very big. The adjustment time is long. When the parameters of controlled plant are changing over time, the parameters of controller could hardly change automatically to adjust to changing environment. Thus, it can’t meet the demand of control quality in the process of controlling piezoelectric ceramic. In order to effectively control the piezoelectric ceramic and improve the control accuracy, this paper replaced the learning algorithm of the BP with the mutation particle swarm optimization algorithm(MPSO) on the process of the parameters setting of BP-PID. That designed a better self-adaptive controller which is combing the BP neural network based on mutation particle swarm optimization with the conventional PID control theory. This combination is called the MPSO-BP-PID. In the mechanism of the MPSO, the mutation operation is carried out with the fitness variance and the global best fitness value as the standard. That can overcome the precocious of the PSO and strengthen its global search ability. As a result, the MPSO-BP-PID can complete controlling the controlled plant with higher speed and accuracy. Therefore, the MPSO-BP-PID is applied to the piezoelectric ceramic. It can effectively overcome the hysteresis, nonlinearity of the piezoelectric ceramic. In the experiment, compared with BP-PID and PSO-BP-PID, it proved that MPSO is effective and the MPSO-BP-PID has stronger adaptability and robustness.

Infrared touch overlay has some problems in multi-touch recognition and trajectory smoothness. In order to deal with these problems, this paper adjusts the Kalman filter for infrared touch overlay. Before the application, it estimates the noise of process and measurement. It analyzes the process noise and measurement noise from test of three different touch trajectories. And then the paper choses the proper parameter for the Kalman filter on infrared touch overlay. The experimental results demonstrate that the Kalman filter with the noise parameter works much better in filtering of the infrared touch overlay's track, compared to the original recognition algorithm.

The hidden danger exists in the power capacitor of power system due to long-time operation under the environment of high voltage. Thus, it is possible to induce serious fault, and the on-line detection system is urgently required. In this paper, two methods of the on-line detection system are compared in order to realize the better real-time condition detection. The first method is based on the STM microprocessor with an internal 12 bit A/D converter, which converts analog signals which is arrived from the sample circuit into digital signals, and then the FFT algorithm is used to accomplish the measurement of the voltage and current values of the capacitor. The second method is based on the special electric energy metering IC, which can obtain RMS (Root Mean Square) of voltage and current by processing the sampled data of the voltage and current, and store RMS of voltage and current in its certain registers. The operating condition of the capacitor can be obtained after getting the values of voltage and current. By comparing the measuring results of two methods, the second method could achieve a higher measurement accuracy and more simple construction.

Evaluation of vibration characteristics for wind turbine blades is one of the important contents in the wind turbine research. This paper uses the compressible flow equations with the preconditioning technique, based on the finite volume method and combined with the LU-SGS algorithm for solving the flow area; meanwhile adopts the two degree of freedom of vibration equation with the vertical and torsional vibration for blades to simulate the vibration trajectory of blade under the aerodynamic force, uses the motion grid algorithm for changes in grid computing domain. Calculation program was developed autonomous in the C ++ platform, and the development of software correctness was verified by contrast the results of the classic cylindrical examples. Finally, the vibration characteristics of a wind turbine blade was given, and the software developed in this paper can provide technical support for wind turbine blade vibration study.

The plasma temperature and electron density is an important content of the research. It is useful for the study mechanism of laser induced breakdown. Two Nd:YAG pulse laser induce iron alloy formation plasma obtaining the 250~370nm spectrum diagram in the experiment. Double pulse spectra and single pulse spectra are compared, the electron density of double pulse is 2×10¹⁷ cm^-3 by Lorentz linear fitting; it is 0.3×10¹⁷ cm^-3 higher than single pulse. The plasma temperature of double pulse is 1.3×10⁴K by using Saha-Boltzmann multi line graph method. The advantages of double pulse laser are over single pulse comparing relationship between electron density and plasma temperature with delay time. Finally, the plasma in local thermal equilibrium based on the experimental results; plasma state meet the sufficient condition of calculation method.

In recent years, semi-passive vibration damping using Synchronized Switching Damping on Inductor (SSDI) technique has been intensively investigated. In this paper, a self-powered semi-passive vibration damping system based on self sensing approach is proposed and investigated. With the self-sensing technique, the same piezoelectric element can be used as a sensor and an actuator. Compared with the other self-powered SSDI approaches, this technique can not only detect switching time without lag, but also reduce the number of piezoelectric elements. Furthermore, a low-power circuit for semi-passive piezoelectric vibration control based on self-sensing technique is designed. Experimental results demonstrate that the self-sensing SSDI system has good damping performance. The performance of the self-sensing SSDI system is also compared with the externally powered system.

While the equipment of Micro-jet wave-guided laser was assembled, high-precision of concentricity and coaxiality between nozzle and cavity are required, which directly or indirectly influent the laser coupling precision of nozzle, the micro-jet stability and the steady length of micro-jet as well. As a result, the measurement of concentricity and coaxiality is important to improve the processing quality of Micro-jet wave-guided laser Through the new digital universal tool microscope measuring both ends of micro nozzle and diameter of nozzle, more resolution the other hand, the backlight detection the edge of nozzle is utilized. When the position of the center of a circle is indirect measured and then find out the concentricity through the uncertainty of the measurement and calculation method. V shaped groove is utilized to make certain its position. Otherwise, digital imaging through setting fixture and the use of new digital universal tool microscope and processed by software, which will cause to reduce measurement human error in tradition, after that, error theory analysis will be carried out, uncertainty theory will be utilized to make the experiment more sure at the same time. Above all, the reliability of data is obtained, compared with the traditional measurement methods are more accurate. Therefore, the processing quality of laser drilling will be enhanced significantly.

A new test method and a measurement system was proposed and developed to evaluate the bending and twisting properties of textile fabrics. The measurement system and the test method is based on the mechanical device, sensors and microelectronics and simulates the dynamic process during the fabric is bent and twisted. The virtual instrument based system can measure the dynamic changes of the signals due to the bending and twisting loads. Derived from the test data, a series of indices are defined to characterize the bending and twisting properties. The test and evaluation method, the experiments and the test results are reported. The analysis of the variance for intra-laboratory test was performed to determine the precisions of the test method and the measurement system. The measurement system provides a method for objective measurement and evaluation of bending and twisting properties of textile fabrics.

Nonlinearity error in double passage heterodyne interferometer is mainly caused by the nonideal properties of optical components. To solve this problem, in this paper, the nonlinearity error caused by nonideal properties of polarization beam splitter(PBS) including transmission coefficient and azimuth is numerically analyzed, and then the mathematical model for nonlinearity error is established and simulated. The results show that the nonlinearity error of the displacement increases from 0.0153 nm to 2.2766 nm with the azimuthal error ranging from 1° to 12°, and the nonlinearity error caused by the transmissivity and reflectivity of PBS is minor and can be ignored. The research results provide a theoretical basis for the reduction of the nonlinearity error in the double passage heterodyne interferometer.

A mathematical model of space target illumination characteristics is established based on the basic theory of radiation by considering geometry, background, and material characteristics of the space target. Using the model, the spatial distribution of scattering light intensity from the space target is calculated with the modeling and blanking technique of target when being illuminated by the sun. The relations of specular reflection with the position, geometry, materials and other attributes of the space target are analyzed. Furthermore, the effect of specular reflection on space target detecting is discussed. A method of characteristic simulation of space target is presented. The simulation result indicates that polyhedral structure, mirror surface, or solar sail is easy to cause specular reflection. It shows the effect of specular reflection is helpful for space target detection and identification.

A new flexible method to calibrate the external parameters of two cameras with no-overlapping field of view (FOV) is proposed in our paper. A flexible target with four spheres and a 1D bar is designed. All spheres can move freely along the bar to make sure that each camera can capture the image of two spheres clearly. As the radius of each sphere is known exactly, the center of each sphere under its corresponding camera coordinate system can be confirmed from each sphere projection. The centers of the four spheres are collinear in the process of calibration, so we can express the relationship of the four centers only by external parameters of the two cameras. When the expressions in different positions are obtained, the external parameters of two cameras can be determined. In our proposed calibration method, the center of the sphere can be determined accurately as the sphere projection is not concerned with the sphere orientation, meanwhile, the freely movement of the spheres can ensure the image of spheres clearly. Experiment results show that the proposed calibration method can obtain an acceptable accuracy, the calibrated vision system reaches 0.105 mm when measuring a distance section of 1040 mm. Moreover, the calibration method is efficient, convenient and with an easy operation.

Fractal dimension is an important quantitative characteristic of a image, which can be widely used in image analysis. Differential box-counting method which is one of many calculation methods of a fractal dimension has been frequently used due to its simple calculation . In differential box-counting method, a window size M is limited in the integer power of 2. It leads to inaccurate calculation results of a fractal dimension. Aiming at solving the issues , in this paper, an improved algorithm is discussed that the window size M has been improved to be able to accommodate non-integer power of 2, and making the calculated fractal dimension error smaller. In order to verify superiority of the improved algorithm, the values of fractal dimension are regarded as parameters, and are applied for image segmentation combined with Ostu algorithm . Both traditional and improved differential box-counting methods are respectively used to estimate fractal dimensions and do threshold segmentation for a thread image . The experimental results show that image segmentation details by improved differential box-counting method are more obvious than that by traditional differential box-counting method, with less impurities, clearer target outline and better segmentation effect.

With the development of technology capability of submarine launching heavy torpedo and the demand of intellectualized combat, the paper raises the concept of torpedo maneuver search and analyses maneuver search opportunity. It is necessary to realize the long range heavy torpedo’s maneuver search that heavy torpedo’s maneuver search can cover the target’s location error which results from launching platform’s position precision and the target’s intentional maneuver when the torpedo is launched. The technology framework of the heavy torpedo’s maneuver search trajectory is set up.

The precision of dimensional measurement plays an important role in guaranteeing the assembly accuracy of its internal components during the upgrading phase of EAST device. In this paper, the experimental research and analysis were done based on three dimensional combined measurement systems, combining Laser Tracker, flexible Measure ARM and measurement fiducials network, which are used for alignment and measurement of EAST components during the assembly process. The error sources were analyzed, e.g. temperature, gravity, welding, and so on. And the effective weight of each kind of error source was estimated by the simulation method. Then these results were used to correct and compensate the actual measured data, the stability and consistency of the measurement results was greatly improved in different measurement process, and the assembly precision of the EAST components was promised.

As the equipment based on Embedded Systems always runs into the interference of 50Hz frequency signal, we usually adopt digital filters to filter 50Hz frequency signal and reserve useful signals. But in order to meet the requirements for real-time processing, we hope the transfer function of the filter will be as simple as possible and the coefficient is integer. This article discusses the design methods of integer coefficients comb filter and gives out two integer coefficients comb filters which meet the requirements for real-time processing.

Au heater is one of the core components of thermo optic effect devices. The reliability of Au heaters affects the lifetime of whole devices directly. In order to explore the influence of shape parameters on lifetime of Au heater, the accelerate life test (ALT) was designed and conducted. Samples with different shape parameters were prepared for the ALT in which the applied current was 500mA and the test temperature was 150°C. The results showed that failure mode of all the different samples was open circuit. The electromigration was found the reason for this kind of failure in test conditions. According to the experimental and finite element simulating results, the fusing break appeared in the transition arc area where temperature gradient was the maximum. It is also can be found that the larger the radius, the later the failure. In other words, lifetime of the thin-film heater with larger transition radius was longer.

Publisher’s Note: This paper, originally published on 26 January 2016, was withdrawn. If you have any questions please contact SPIE Digital Library Customer Service for assistance.

Based on the structure platform of the gas turbine engine, the components of variable cycle engine were simulated by using the component method. The mathematical model of nonlinear equations correspondeing to each component of the gas turbine engine was established. Based on Matlab programming, the nonlinear equations were solved by using Newton-Raphson steady-state algorithm, and the performance of the components for engine was calculated. The numerical simulation results showed that the model bulit can describe the basic performance of the gas turbine engine, which verified the validity of the model.

In view of problem of the existing coal mine belt conveyor is no field bus communication function, two levels belt conveyor electric control system design is proposed based on field bus. Two-stage belt conveyor electric control system consists of operation platform, PLC control unit, various sensors, alarm device and the water spraying device. The error protection is realized by PLC programming, made use of CC-Link bus technology, the data share and the cooperative control came true between host station and slave station. The real-time monitor was achieved by the touch screen program. Practical application shows that the system can ensure the coalmine production, and improve the automatic level of the coalmine transport equipment.

Abide by the design principles of mine intrinsically safe circuit, according to the need of underground communication in coal mine, the paper proposed a design scheme of DC carrier telephone which can dial. The design circuit of the telephone is introduced in detail. The telephone’s voice signals are generated by the microphone. After enlarged then the voice signals are modulated to frequency signals by LM567 chip. The frequency signals are coupled by transformer and then transmitted by 12V DC power supply line to the other voice terminals. In the voice terminal the signals are demodulated by LM567 demodulation circuit and enlarged by LM386, then, the amplified audio signals are output from a speaker. The dialing circuit is designed based on the STM32 MCU. The dial information is transmitted to the other telephone terminals by CAN bus. The measured distance calls is greater than 2000m, volume is larger than 85dB, good results.

The medium-low orbit satellite is used as observation satellite to make parameters estimation and error analysis of the spacecraft orbit. Based on the variable mass particle dynamics, the simplified motion equation of observation satellite was numerically solved by the Runge-Kutta method, and the position of the observation satellite at any time was calculated more accurately. Based on the variable mass particle dynamics, the orbit estimation equation of the spacecraft was given, and the position and the velocity data of the spacecraft at any time were numerically solved by the Runge- Kutta method, and then the fitting curves of these data were obtained. The residual analysis was made to test the output from the model, which indicated that this model is acceptable and valid.

The properties of a solid specimen depend on its elastic property and microstructures, which are not only in nano size but also in micro-sized scale. Impulse acoustic microscope is a technology, employing a focused ultrasound probe beam in immersion to penetrate into a solid specimen, and to detect the internal micro-sized structure by acoustic imaging for a solid bulk material. Acoustic lens produces such a probe beam into a specimen and receives response radiations reflected from the specimen. The characters of an acoustic lens determine the precision and quality of acoustical imaging; and the relevant controlling techniques are also important peripheral elements for the system. But it is ignored or has not raised attention that the acoustic interaction behavior between the focused ultrasound probe beam and an internal micro-sized structure in a bulk — diffraction, scatter phenomena — usually also presents an inevitable impact on acoustic images. In this paper, the authors try to introduce these principles to demonstrate that these factors are the fundamental keys, to promote the performance of Impulse Scanning Acoustic Microscopy.

The angle measurement technology is very important in precision manufacture, optical industry, aerospace, aviation and navigation, etc. Further, the angle encoder, which uses concept ‘subdivision of full circle (2π rad=360°)’ and transforms the angle into number of electronic pulse, is the most common instrument for angle measurement. To improve the accuracy of the angle encoder, a novel self-calibration method was proposed that enables the angle encoder to calibrate itself without angle reference. An angle deviation curve among 0° to 360° was simulated with equal weights Fourier components for the study of the self-calibration method. In addition, a self-calibration algorithm was used in the process of this deviation curve. The simulation result shows the relationship between the arrangement of multi-reading heads and the Fourier components distribution of angle encoder deviation curve. Besides, an actual self-calibration angle encoder was calibrated by polygon angle standard in national institute of metrology, China. The experiment result indicates the actual self-calibration effect on the Fourier components distribution of angle encoder deviation curve. In the end, the comparison, which is between the simulation self-calibration result and the experiment self-calibration result, reflects good consistency and proves the reliability of the self-calibration angle encoder.

It's necessary for automobile to detect and adjust four-wheel alignment parameters regularly, due to the significant effect on improving stability, enhancing security and reducing tire wear of automobiles. In order to measure the parameters that determined by relative position and posture of four wheels to the automobile cab, this paper proposes a method which applies monocular vision of linear structure light to wheel pose measurement. Firstly, space coordinates of feature point cloud are calculated out from the principle of structured light. Then, an algorithm is designed to determine the normal vector of wheel tangent plane and measure the wheel pose. Finally, actual experiments that by evaluation of adjusted wheel angle measurement are carried out to verify the system accuracy. The corresponding studies can be applied in designing and developing 3D four-wheel alignment system that based on structured light.

Considering the relatively low price, convenience and potential high accuracy of Digital Fringe Projection techniques (DFP), it has begun widely to use in static or even in dynamic scene for object three-dimensional reconstruction. A conventional DFP system utilizes projector to project a sinusoidal fringe patterns onto object surface, which is generated by computer. By further fringe analysis, it could retrieve the phase for reconstruction. However, this technique is not trouble free for various factors such as camera noise, nonlinear intensity response between camera and projector, especially Gamma effect, which seriously distort the sinusoidal wave. Since 1-bit binary structure patterns would not be affected by Gamma effect, S Lei proposed squared binary defocusing techniques to overcome the limitation of DFP techniques above. However, by defocusing the projector, squared binary defocusing technique has low SNR property, whose precision will be affected by various error factors easily. This paper proposes two types of error elimination algorithms of squared binary defocusing techniques. Principle of each technique will be presented, and the experimental results show the differences between the two algorithms.

As a method of non-contact, binocular vision technique is important for vibration test. When measuring the vibrating objects, the frame rate of cameras must match the vibration frequency of the object. If the objects vibrate in high-frequency, it will lead massive image data. However, the speed of data transmission is limited by massive data. Thus, in order to deal with these data, data compression is inevitable before data transmission. Binarization is a simple and fast process to minimize the size of the image data. But the pixel locations of the marked points may change after binarization, which will inevitably affect the reconstruction of the marked points and further influence the precision of the measurement data. In this paper, the parameters which influence the position of various types of marked points are studied after binarization for dynamic test. A vibration table is employed to provide a standard moving motion. The frequency and amplitude is given by the controller of the vibration table. Three types of marked points, dot, circle and cross, are studied in this research. The obtained images in the dynamic test are minimized after binarization, and the pixel locations of the marked points are obtained. The change of pixel location is studied for the different types of the marked points with the comparison experiments and the precision of the reconstruction is investigated later.

Calibration is the basis of three-dimensional (3D) reconstruction for machine vision technology. Nowadays, the most widely used calibration method among computer vision is the technique for binocular stereo measurement. However, binocular stereo vision has limited view field which is difficult to measure large-scale mechanical components synchronously. Thus, enlarging the view field is urgent in need for the large scale measurement. With the application of multi-camera system, the calibration for cameras with different focal lengths is required. In this paper, a method aiming at calibration problems for multi-camera system of different focal lengths is proposed. An imaging model for multi-camera system with various focal lengths is analyzed. The Harris corner detector is applied to determine the relationship between signal camera and checkerboard. Finally, the external parameters of different cameras can be obtained by the link with the checkerboard. The calibration results indicate that the calculation method used in this work can calibrate multi-camera with various focal lengths.

Multi-cameras calibration using spheres is more convenient than using planar target because it has an obvious advantage in imaging in different angles. The internal and external parameters of multi-cameras can be obtained through once calibrat ion. In this paper, a novel mult i-cameras calibration method is proposed based on multiple spheres. A calibration target with fixed multiple balls is applied in this method and the geometric propert ies of the sphere projection model will be analyzed. During the experiment, the spherical target is placed in the public field of mult i-cameras system. Then the corresponding data can be stored when the cameras are triggered by signal generator. The contours of the balls are detected by Hough transform and the center coordinates are determined with sub-pixel accuracy. Then the center coordinates are used as input information for calibrat ion and the internal as well as external parameters can be calculated by Zhang's theory. When mult iple cameras are calibrated simultaneously from different angles using multiple spheres, the center coordinates of each sphere can be determined accurately even the target images taken out of focus. So this method can improve the calibration precision. Meanwhile, Zhang's plane template method is added to the contrast calibrat ion experiment. And the error sources of the experiment are analyzed. The results indicate that the method proposed in this paper is suitable for mult i-cameras calibrat ion.

Energy harvesting (EH) derives from the idea of converting the ambient energy into electric energy, which can solve the problem of DC supply for some electronic equipment. PZT is a typical piezoelectric material of inorganic, which has been developed as EH devices to transfer ambient vibration energy into electric energy. However, these PZT devices require relatively violent excitation, and easy to be fatigue fracture under the resonance condition. In this paper, PVDF, which is a kind of soft piezoelectric polymer, is adopted for developing transducer. The PVDF devices are flexible and have longer life time than PZT devices under the harmonic environment. The EH researches are mainly focused on the development of energy transfer efficiency either by the mechanical structure of transducer or the improvement of circuit. However, the practicality and stability of the EH devices are important in the practical engineering applications. In this paper, a charge amplifier is introduced in the circuit in order to guarantee the stability of the battery charging under small ambient vibration conditions. The model of the mechanical structure of PVDF and the electric performance of circuit are developed. The experimental results and simulation show that the stability of battery charging is improved and the working time of DC equipment is prolonged.

An online multi-node microfludic pressure measuring system was designed in the paper. The research focused on the design of pressure test circuit system and methods on dealing with pressure data collecting. The MPXV7002 micro-pressure sensor was selected to measure the chip inside channel pressure and installed by a silicone tube on different micro-channel measured nodes. The pressure transmission loss was estimated in the paper, and corrected by the filtering and smoothing method. The pressure test experiment was carried out and the data were analyzed. Finally, the measuring system was calibrated. The results showed that the measuring system had high testing precision.

Aiming at the problems of existing crack extraction algorithms which are difficult to achieve fast and accurate crack extraction of image, an algorithm of crack detection based on Median Filter and Hessian Matrix is proposed. Firstly, median filter of crack gray image in 4 directions, Level, 45 degree, vertical and -45 degree, is conducted, by which noises are removed and roughly extracted crack is obtained. Then according to the Hessian matrix feature of extracting image linear feature, convolution of Differential operation of the Hessian matrix is adopted, and crack is further extracted through eigenvalues response and changing standard deviation of Gaussian function. The proposed algorithm validity is verified by comparison with other crack extraction algorithm. The results show that this algorithm has obvious accuracy rate in crack extraction.

In order to find the best measurement method to get the most reasonable result, the test on oblique elliptical cylinder of transfer arm precision component is studied in this paper. The oblique elliptical cylinder is measured through Qindos 7.0 of PMM-C. Firstly, pivoting support is adopted to compensate the tilt angle. Then coordinates is set approximately to get a standard elliptic equation which result in an axis. This axes will be used to modify the coordinates set previously. Such a modification is repeated multiple times until to get a more precise axes. Meanwhile multi-constraint approaches successively to measure major and minor axis of ellipse. Experiment shows that sophisticated parts can be tested through the method stated in this paper and the result is more precise.

In order to enrich the production method of micro-fluidic chip and simplify its processing technology, the paper discussed the double-sided adhesive layer for channel layer, with PMMA (polymethyl methacrylate) for fabrication of microfluidic chip with the cover plate and the bottom plate. Taking 40 mm (long) x 20 mm (wide) x 2.2 mm (thick) liquid drop to separate the microfluidic chip as an example, details the design and machining process of the chip. Experiments show that surface quality is high and processing speed is fast when using this technology to process the chip. Thus, it can realize the mass production of micro fluidic chip.

Speckle interferometry is a method of measuring structure’s tiny deformations which requires accurate phase information of interference fringes. The phase information is acquired by micro-displacement produced by piezoelectric ceramic (PZT). In order to drive the PZT micro-displacement actuator, a multi-functioned and programmable PZT power supply with high precision is designed. Calibration experiment has been done to the PZT micro-actuator in speckle interferometry. Some experiments were also done to test its relevant characteristics. The experiment results show that it has high linearity, repeatability, stability, low ripple and can meet the requirement of the reliability and displacement accuracy in speckle interferometry.

A new relative orientation w local parameter optimization method of the essential matrix for the large scale close range photogrammetry is presented in this paper to improve the accuracy and stability of the measurement system. For the matched images, according to the closed-loop polynomial algorithm, the essential matrix is initialized, and an iterative algorithm based on local parameter optimization is proposed. Then the relative exterior orientation parameters are solved from the essential matrix, and only one correct solution is determined by the Cheirality constraints. The orientation experiment of the expandable truss microwave antenna profile measurement is carried out to verify the accuracy and reliability of the new method. Compared with the traditional methods, this new method has minimum projection error and the least iterations, and it will play a key role in the performance improvement of the whole system.

During the spacecraft assembly process, the posture of the aerospace camera to the spacecraft coordinate system needs to be measured precisely, because the posture data are very important for the earth observing. In order to measure the angles between the camera optical axis and the spacecraft coordinate system’s three axes x, y, z, a measurement scheme was designed. The scheme was based on the principle of space intersection measurement with theodolites. Three thodolites were used to respectively collimate the camera axis and two faces of a base cube. Then, through aiming at each other, a measurement network was built. Finally, the posture of the camera was measured. The error analysis and measurement experiments showed that the precision can reach 6″. This method has been used in the assembly of satellite GF-2 with satisfactory results.

Current infrared touch overlay has problems on the touch point recognition which bring some burrs on the touch trajectory. This paper uses the target tracking algorithm to improve the recognition and smoothness of infrared touch overlay. In order to deal with the nonlinear state estimate problem for touch point tracking, we use the extended Kalman filter in the target tracking algorithm. And we also use the data fusion algorithm to match the estimate value with the original target trajectory. The experimental results of the infrared touch overlay demonstrate that the proposed target tracking approach can improve the touch point recognition of the infrared touch overlay and achieve much smoother tracking trajectory than the existing tracking approach.

The purpose of this study is to develop with low cost, high precision, low contact force micro-CMM that has fiveaxis scanning touch probe. In this study, the measurement performance of the proposed system is enhanced through the use of a rigid aluminum double-arch-bridge structure to support the five-axis scanning touch probe. Furthermore, the reliability of the scanning probe mechanism of three degrees of freedom was analyzed and validated. in addition two axis (A-axis and C-axis) was added on the scanning probe. This design can be achieved independent of measurement, and minimize the dynamic error. In terms of software, a PC-Based controller was integrates five-axis motion systems with the measurement system through a five-axis control card and a data acquisition card. It also completed the functional modules of Set, Manual and Measurement. In the measurement system, we used our own developed coordinate measurement software, with the XYZ platforms system, rotating mechanism and scanning probe to achieve complex surface measurements. The micro-CMM has a working volume the micro-CMM has a working volume of 80×80×40 mm³ , and the overall dimensions is 486 × 486 × 448 mm.

A key technology of multi-camera visual measurement system is global calibration. The global calibration methods existed either has disadvantages such as high cost and complicated operation, or has limited application areas only for visual system based on stereo vision. A convenient global calibration method for multi-camera system based on two planar targets is proposed in this paper, and the pose relation between the two targets can be unknown. This method is not only suitable for system based on stereo vision, but also for system based on monocular vision. It has been used in the factory-calibration of four-wheel aligner consisted of 2 or 4 cameras, and calibration precision meet the requirement.