In order to eliminate the noise and information coupling in the sensing information of the multi-sensor information measuring system, the paper propose a new modeling method, which adopts a distributed sensing mode, uses wavelet multiscale method and multivariate interpolation decoupling approach based on multiscale characteristic respectively in the de-noising and decoupling of sensing information, then uses scalars weighting method under minimum variance to estimate each sensor's contributing rate, and finally obtains the optimal fusion estimation of multi-sensor information. The experiments on the liquid component measurement in complex environment indicate that the precision of the modeling method can reach ±1.5%.
Dynamic error separation is still an important subject and research high tide nowadays. Along with the development of
time series and modern spectrum analysis, dynamic error separation combined with Mathematical Modeling becomes a
main trend. A new algorithm for separating dynamic error is proposed in this paper. It is based on time series and modern
spectrum modeling principle. Firstly, dynamic random error is separated by dint of time series model combining
recursive instrumental variables and Kalman filter. Then the trending component and the harmonic component are
respectively identified by using Stepwise Rejection-Accept Regression Analysis and Pisarenko spectrum analysis
method. Finally, compared with the prior information, dynamic system error is mostly separated. Separation of the error
components is verified through simulation experiment. The performances of algorithm are illustrated according to the
results obtained from simulation. It shows that 99.53% of random errors are separated, in addition, the estimation of trend
component and frequencies of periodic components (the corresponding amplitudes) of system error are also obtained.
Proc. SPIE. 7130, Fourth International Symposium on Precision Mechanical Measurements
KEYWORDS: Manufacturing, Control systems, Process control, Integration, Computer aided design, Data conversion, Automatic control, Global Positioning System, Standards development, Design for manufacturability
For the purpose of design, manufacture and verification, a consistent geometrical model for the product function is
required. In the product life circle, full implementation of the GPS standard is to effectively analyze, optimize and
control the factors related to the quality of product geometrical dimension. It's very difficult for the designer to manage
them. This paper first analyzed GPS's role in product's quality control, then typical CAx data format and interface are
studied to realize data bidirectional transform. The method is proposed to integrate GPS standards in typical CAx by
using TOOLKIT interface provided by Pro/ENGINEER. Associate GPS modules are embedded. Finally, integrated
platform is developed. The integrated platform can reduce the application costs of GPS standards; moreover, it can
achieve the automatic control and optimization of product's geometric quality.
Virtual instruments (VIs) require metrological verification when applied as measuring instruments. Owing to the
software-centered architecture, metrological evaluation of VIs includes two aspects: measurement functions and software
characteristics. Complexity of software imposes difficulties on metrological testing of VIs. Key approaches and
technologies for metrology evaluation of virtual instruments are investigated and analyzed in this paper. The principal
issue is evaluation of measurement uncertainty. The nature and regularity of measurement uncertainty caused by software
and algorithms can be evaluated by modeling, simulation, analysis, testing and statistics with support of powerful
computing capability of PC. Another concern is evaluation of software features like correctness, reliability, stability,
security and real-time of VIs. Technologies from software engineering, software testing and computer security domain
can be used for these purposes. For example, a variety of black-box testing, white-box testing and modeling approaches
can be used to evaluate the reliability of modules, components, applications and the whole VI software. The security of a
VI can be assessed by methods like vulnerability scanning and penetration analysis. In order to facilitate metrology
institutions to perform metrological verification of VIs efficiently, an automatic metrological tool for the above
validation is essential. Based on technologies of numerical simulation, software testing and system benchmarking, a
framework for the automatic tool is proposed in this paper. Investigation on implementation of existing automatic tools
that perform calculation of measurement uncertainty, software testing and security assessment demonstrates the
feasibility of the automatic framework advanced.
According to the nonlinear dynamic characteristics and uncertainty of Multi-sensor Integrated System(MSIS), the Multi-sensor Cooperative Measurement Mechanism(MSCMM) is studied based on Synergetics. By dint of analogy method, the MSCMM is described deeply and its model with the dynamic cooperation-competition-harmony course is proposed. Then dynamics equation of MSCMM model is established. With the Slaving Principle(SP), eliminating stable modes, the potential function of order parameters equation is acquired. Through deducing instability limit of potential function, the cooperative degree ξ is obtained. After the MSIS becomes stable, the uniform expression of accuracy η of multi-dimension uncertainty is achieved. Sequentially, the assessment index system is confirmed, including cooperative degree ξ, accuracy η, iterative error ψ and stability steps L. Finally, the application in multi-parameter safety monitoring for electric transmission line is introduced. The experiment results show that the MSCMM possesses self-association and self- recover, enlarges greatly time-space range of multi-sensor system and decreases effectively uncertainties.
To obtain the suspending state and position of object in opaque liquid is significantly important and there often meet
many problems especially in the condition that suspending object will interact with the liquid. Traditional detection
methods measurement accurate is too low or it's harmful to human health. One novel ultrasonic detect method was
brought forward. Through analyzing the test environment and the features of ultrasonic test, positive and negative
differential ultrasonic measure principle is presented. The experimental plat is setup and applied to secondary magnetic
buoyancy object position measurement in the novel magnetic fluid inertial sensor. The results show that the secondary
magnetic buoyancy position and its suspending state are accurately measured.
Traditional cantilever accelerometer generally has the problems of mechanical friction and the distort invalidation of elements which the magnetic fluid (MF) acceleration sensor presented in this paper utilizing a moving magnet fully suspended in MF could solve. This MF sensor is simple in the mechanism with controllable measurement range and precision. The moving magnet was balanced by the repulsive force of magnet in axial and MF second-order buoyancy in radial respectively. Its sensor model was brought forward and simplified to obtain its mathematical model. The MF magnetoviscous property that can realize the controllability of viscosity was discussed. The relations of sensor kinetic characteristic to various parameters including MF viscosity, acceleration and magnetic field energy were analyzed. The results show the moving trend is uniform under different acceleration. Through adjusting the magnetic field intensity to modify MF viscosity, it will get good astringency and keep balance time within 0.2s.
In the circumstances of low luminance, visible assistant light is not available or convergence is very similar to the background or syncretism to each other, research on the local 3-D image restoration method is of great sense. Generally to restore 3-D image from binocular 2-D image, active vision is in need. Otherwise the application would be only constrained in objects of simple shape. A local 3-D image restoration method based on infrared grid raster was proposed in the paper. Its principal is irradiating the goal object by non-structure infrared grid raster, catching the object area image by double CCD infrared camera and distilling the grid data from the image. Then the 3-D grid image of the target was restored by the binocular image matching from the grid data. Finally, the practice 3-D image of the object is fitted from the 3-D grid image. By using the infrared grid raster, the target could be added with additional grid without frightening it and the process was quite efficient. At present, the stereo image restoration based on grid and grid raster was realized. Thus, through optimizing the existing image pretreatment technology, character distilling technology and stereo matching technology, the clear local 3-D image of the target would be restored faster even in the case of lower environment luminance while the visible assistant light is forbidden.
A robust-fusion optic fiber sensor technology of proximity distance and orientation integration is studied in this paper. A novel optic fiber sensing head with redundant information, which can measure distance and orientation in any pose as well as compensate fluctuation caused by changing parameters such as surface reflectivity, light intensity and characteristic shifting from photoelectric-converter device, is proposed. The implement method of sensor network compensation is introduced.
An improved BP network arithmetic, which can enhance the dynamic characteristic and measurement accuracy of the sensing system, is presented. To speed up the convergence rate of BP network training, GA -BP training method is applied. An intelligent signal detecting and processing system based on DSP is designed, the strong data processing ability of DSP makes the system hardware structure simplified. The method of moderate output light power control is put forward for enlarging the measuring range. Experiment result shows that robust-fusion optic fiber proximity sensor system has the distance measuring range of 0.1~19.9mm and the orientation measuring range of 0~25°. The measuring time of each point is 92.5ms.
A novel optical fiber proximity sensor for robot is proposed, which has fairly storng compensation abilty to such factors as variation of optical source power and object reflectance. Composed of four receiving optical fiber, the sensor has a simple structure. Utilizing rotation freedom degree of robot's manipulator, it can measure the orientation and distance of the manipulator relative to the object. This paper introduces the operating principle, the necessary and sufficient condition of the sensor's measuring pose, the optimum structure designing method which taking the mininum of measuring values relative error as objective function, emphasis is lays on the detecting technology based on Self Scan Photo Diode Array and the method for measure range enlarging,the sensor's measuring attittude adjusting and real-time data processing of sensor are also gone into detail.
Considering the diameter of steel-pipe is from 910mm to 1500mm, the weight is from 1000Kg to 10000Kg, the length is above 6 m and the request of factory, this paper presented the length and weight measuring system for steel-pipe in fieldwork. The relative measuring method with double CCD (Charge Coupled Device) cameras, capturing and processing the images and acquiring the length of steel-pipe with industrial control computer is put foreword. With emphasis on the system structure, measuring principle, demarcating technology and method how to improve the system reliability are investigated. Comprising simple hardware this system is easy to build and demarcate, and the info-benchmark determining and specially the image recognition are depended on software technology, which choosing homologous equivalent image cell weight to convert the length and get higher measuring precision by studying the character of the shape and placement of the pipe termination point image. Via locale run, this system was proved to be firm and the measuring error is less than 10/00.
Screw assembly takes certain proportion in assembly work, and to achieve automatic screw flexible assembly is a difficulty in automatic flexible assembly system. In view of special requirements in robot screw flexible assembly, the paper proposes a new optic fiber sensing structure which detects the orientation and position errors of screws. The paper proposes a novel multi-optic-fiber-sensor measurement and treatment method based on SSPA that works under photoelectric diode electrical charge storage style and has high detecting sensitivity. At the same time, the multi-route signals going through the same SSPA apparatus make the system have higher capability/price ratio. As the signals are serially sampled in an instant by the same apparatus (SSPA), the measured object's actual situation is reflected and the influent factors such as changes caused in different time by light path and measured object are eliminated. And the precision of the sensor is also increased. A new method by changing clock frequency of SSPA and controlling the output of light source power is proposed to enlarge SSPA's detecting range. Through the treatment method of partitioning the multi-output BP network into several single-output ones and the subsection of variables' value between input and output, the dynamic capability is improved consumedly; At the experimental platform based on the opticfiber- sensing-technology the experiment successively accomplishes the initial screwing process of M8 screw and bolt with orientation warp of 0~100 and position error of 4—12mm. When the orientation warp is 9.24° and initial position error is 8.72mm, the time spent at initial screwing process is 20 seconds. If the pose warp is smaller, the time will be shorter.
Considering that the resistance of macromolecule resistor varies in a wide range and humidity sensor component is sensitive to temperature as well, a intelligent high- precision macromolecule resistance temperature/humidity instrument was proposed in this paper, the instrument is based on the integration of frequency-and-period-measuring method, and sensing characteristic calculation and compensation using interpolation. Practical applications show that the instrument has the advantages of high precision, simple peripheral circuit, low cost, suitability for remote measurement, strong ability of anti-interference and wide operation range.
A novel four-eyes robust optical fiber distance and orientation measuring integrated proximity sensor is presented in this paper. The transducer can measure the distance and orientation of the objects surface at the same time, and is insusceptible to the fluctuation of the optical power output and variation of the object surface's reflectivity. The transducer's measuring attitude control is one of the important content studied in this paper. Based on the prior research, which verifies that the measuring pose does exist and there is only one such attitude, further study on optimize the attitude adjusting control is done to improve the systems real time performances. In view of the complexity of the transducer's mode, an improved BP neural network data processing method is proposed to solve the difficulty in real time data processing. By partition the multi-output BP network into several single output ones and subsection the range of input variables, the sensor's accuracy of pose estimation is significantly increased.
The accuracy of intensity modulation optical fiber sensors worsens greatly due to disturbances such as temperature fluctuation. This paper reports a novel m X n network compensation technique which can be simultaneously applied to many fiber sensors to minimize the degradation. We demonstrate a m X n network (m, n are integers and greater than 1) can compensate (m-1)(n-1) sensors at one time. Further analysis indicates that a m X n compensation network can be looked as the combination of (m- 1)(n-1) four-node networks or three-node networks depending on its structure. Furthermore, its compensation potential is similar to elementary single-sensor networks.