This paper describes a vision-based system that monitors the yarn density of woven fabrics on-line. The system is described in terms of its two principal modules, namely, the image acquisition and the image analysis subsystems. The image acquisition subsystem is implemented with standard components on a low-cost personal computer platform. These components consist of a line-scan camera, a DSP-based image acquisition and processing card, and a host personal computer. The image acquisition process is controlled by a software module that runs on the DSP board and accumulates a 2D image suitable for the density measurement algorithm. The image analysis subsystem, which also runs on the DSP board, implements a novel, yet straightforward, algorithm that utilizes the discrete Fourier transform for monitoring the yarn density of the fabrics from the acquired images. In this algorithm, the Fourier spectrum of the images is covered by contiguous, concentric annular regions that have a prespecified width. THe spectrum values within each annular region are summed, normalized, and subsequently used to produce a 1D signature. Simple statistics of the obtained signatures are the basis for characterizing the fabric in terms of its yarn density. The described system is tested on seven fabrics with common properties but varying yarn densities and has shown to be accurate within 2 yarns per inch in either direction. It is also shown that the obtained accuracy, which is primarily a function of the image resolution, can be greatly improved.

We have developed an automated pattern verification technique. The output of an automated optical inspection system contains many false alarms. Verification is needed to distinguish between minor irregularities and serious defects. In the past, this verification was usually done manually, which led to unsatisfactory product quality. The goal of our new automated verification system is to detect pattern features on surface mount technology boards. In our system, we employ a new illumination method, which uses multiple colors and multiple direction illumination. Images are captured with a CCD camera. We have developed a new algorithm that uses CAD data for both pattern matching and pattern structure determination. This helps to search for patterns around a defect and to examine defect definition rules. These are processed with a high speed workstation and a hard-wired circuits. The system can verify a defect within 1.5 seconds. The verification system was tested in a factory. It verified 1,500 defective samples and detected all significant defects with only a 0.1 percent of error rate (false alarm).

Conventional computer vision approaches towards object recognition and pose estimation employ 2D grey-value or color imaging. As a consequence these images contain information about projections of a 3D scene only. The subsequent image processing will then be difficult, because the object coordinates are represented with just image coordinates. Only complicated low-level vision modules like depth from stereo or depth from shading can recover some of the surface geometry of the scene. Recent advances in fast range imaging have however paved the way towards 3D computer vision, since range data of the scene can now be obtained with sufficient accuracy and speed for object recognition and pose estimation purposes. This article proposes the coded-light range-imaging method together with superquadric segmentation to approach this task. Superquadric segments are volumetric primitives that describe global object properties with 5 parameters, which provide the main features for object recognition. Besides, the principle axes of a superquadric segment determine the phase of an object in the scene. The volumetric segmentation of a range image can be used to detect missing, false or badly placed components on assembled printed circuit boards. Furthermore, this approach will be useful to recognize and extract valuable or toxic electronic components on printed circuit boards scrap that currently burden the environment during electronic waste processing. Results on synthetic range images with errors constructed according to a verified noise model illustrate the capabilities of this approach.

A novel optical information processing system by synthesis of the coherence function is proposed. By modulating the frequency of a laser diode in an interferometer with appropriate waveform, the system synthesizes the coherence function into a delta-function-like peak at a depth tunable by the frequency modulation parameter, and thus can extract 2D images from 3D object at arbitrary depth in the form of interference component. To detect selectively the interference component, a 2D optical lock-in amplifier with the microchannel spatial light modulator is developed, so that the limitation to the depth resolution introduced by the holographic detection which was used in our previous systems is overcome, Selective image extraction is demonstrated successfully with neither mechanical scanning nor digital calculation.

Two novel self-calibration methods are proposed for calibrating fringe-interpolation errors of interferometers with nanometer resolution, and the basic characteristics of the methods are discussed. The one method owes its accuracy to the repeatability of the displacement of PZT actuator which gives input displacement to the calibrated interferometer. This method needs only one interferometer. The other method uses two interferometers, which has been proposed for the calibration of linearity error of general displacement sensors. The calibration accuracy of this method theoretically approaches the resolution limit of the interferometer, which is determined by the signal-to-noise ratio and the stability of the measurement system. A compact differential interferometer that uses a laser diode as the light source has been developed in order to demonstrate the viability of the proposed former calibration method. As the specimens for the other method interferometers using optical fiber have been developed. The reflected beam from the one end of the optical fiber and that from the target mirror make interference fringes in this interferometer. The conventional fringe-counting and phase modulation methods are combined in order to extend the measurement range and improve the resolution of these error which causes interpolation error in the interferometer. The calibration results have shown that both methods can attain nanometric accuracy judging from the repeatability. Therefore it was confirmed that the absolute nanometric calibration is realized with each method when the wave length of the interferometer is known.

This paper presents a new algorithm for matching two sets of 3D data points. It has a better polynomial time complexity, O(N^2.5), over previous techniques. There is not restriction on the amount of missing point-pair correspondence between the two sets of data, provided that a majority of the data points between the two images are consistent in terms of rigidity constraints. The algorithm makes use of the Hough bucketing technique for determining the optimal solution, with a modest 1D Hough space for the rotational space search. The search in the translational space is carried out sequentially. No restrictions on al six transformation parameters are imposed and any arbitrarily shaped surface can be registered provided a unique solution exists. The only assumption made is that the surface be piece-wise smooth to allow surface normal calculations on most regions except at discontinuity boundaries. Experimental results showed successful registrations of a simple bottle and a couple of anatomical surfaces captured in 64 by 64 range images with the execution time of about half a minute per registration on a personal computer.

An optical probe for profile inspections of mirror surfaces is developed. This probe can detect the displacement and angle at one point on the measured surface simultaneously. Both the displacement meter and the angle meter of the probe use position sensing detectors (PSD) to detect the position of the optical spot. The principle of the displacement meter is the image formation system, and that of the angle meter is the autocollimation. The displacement meter and the angle meter have two important characteristics. One is the good linearity, the other is that they can detect the displacement and angle independently without interfering with each other. An optical fiber output is used as the light source so that the probe is made compact and to have good characteristics. To eliminate influences of disturbance lights, the light intensity of the laser diode is modulated by a sine wave of 20 kHz, only the position signal is taken out from signals obtained from the PSD in the demodulation circuit. According to the geometrical relation and the active size of the PSD, the displacement meter can measure more than 1000 micrometers and 120 minutes (arc) with good linearity, respectively. Estimating from the signal to noise ratio of the system, the displacement resolution and the angle resolution are 10 nm and 0.1 arcsec, respectively. Some experimental results to confirm the performance of the proposed probe are shown in this paper.

It is well known that the low-coherent light source being used in interferometer permits to register the zero path difference with comparably wide range of measurement definition. This property is often used to determine the surface displacements by corresponding moving of the reference mirror and measuring its position. The conditions of measurement definition become more complex when the object being inspected has a non-smooth surface and there are many surface points which to zero path-difference condition are satisfied in different referent mirror positions. Such conditions were analyzed statistically by means of calculation of intensity cross-correlation functions of interference patterns performed in initial and consequent non-smooth surface positions. The tolerant range of the meanings of angular spectrum frequency deviations and lateral displacements of rough surface was determined by computer simulations. Different spectral characteristics and coherence lengths of interferometer illumination were verified and capacity of researched method was confirmed.

To secure clean water, we need to monitor water quality and detect out harmful materials, if any contained in the water, as early as possible. In general, fish are believed to be more sensitive to water quality than humans are. When fish are moving slowly in a cluster, the water quality is believed to be good enough. However, fish keep afloat on the water or they behave wildly when poisonous materials are added into the water. This paper describes the system which visually inspects water quality by analyzing the motionality of fish. The motionality features are defined by characterizing changes of behavioral patterns of fish. These features are then used in making a fuzzy decision about water quality. The methodology described in this paper is expected to be reliable, and to enable quick and accurate detection or assessment of hazardous chemicals contained in the water.

In this paper we summarize our results and methods in modeling and representing free-form objects by implicit polynomials, and outline the application of this approach to the industrial inspection problem. Implicit polynomials have been widely used in the computer vision and graphics communities for many years with their flexibility, robustness and invariant features. The effectiveness of the use of this representation hinges upon two factors; the stability of the implicit polynomial fitting procedure and the segmentation of the object shape into manageable pieces. In much of the previous work, algebraic invariants of implicit polynomials have been used for estimation or recognition. In this paper, we propose a general multi-scale free-form object modeling and recognition framework where shape information at different scale is captured by different degree and size polynomials (patchlets). We also show that pose estimation and in turn object recognition can be done without using the algebraic invariants. To accomplish this a closed-form pose solution is obtained by comparing the corresponding patchlets. An overview of a free-form object recognition and inspection system built upon these results is given in the paper.

The paper present a parallel implementation of an image processing algorithm for the on-line, non-destructive quality assurance of the non-woven, fibrous web materials. The task of the algorithm is to compute the material microstructure descriptors. The premise underlying this work is that the microstructure determines the performance of the material and characterization of the microstructure may be used to predict material performance. The algorithm for estimating material performance is derived for the use on the cellular neural network universal machine, fast parallel analog architecture which lends itself to real-time processing.

We discuss the uniqueness of 3D shape recovery of a polyhedron from a single shading image, and propose an approach to uniquely determine the concave shape solution by using interreflections as a constraint. We show that if interreflection distribution is not considered, multiple convex (or concave) shape solutions usually exist for a pyramid with three or more visible facets. However, if interreflection distribution is used as a constraint to limit the shape of polyhedron, polyhedral shape can be uniquely determined. Interreflections, which were considered to be deleterious in conventional approaches, are an important constraint for shape-from-shading.

Solder paste inspection, i.e. reconstruction of the 3D shape of the solder paste printed on surface mount technology component pads, is a major inspection task in the printed circuit board manufacturing process. We have investigated the use of machine vision methods based on structured light and phase measurement for on-line solder paste inspection. With these methods a periodic light pattern is projected onto the object and imaged by a camera from a different viewpoint. Since the imaged pattern is phase-modulated according to the topography of the object, suitable phase- extraction techniques enable reconstruction of the 3D shape. In a previous paper we have shown that the Fourier-based phase-extraction technique allows recovery of the 3D shape of solder paste on pads but is too slow for effective on- line inspection. In this paper we describe a new profilometry technique which uses a fast demodulation scheme and simple DSP operators such as comb filters and moving averages. Experimental results show that the new technique is equivalent to the Fourier technique with respect to reconstruction of the 3D shape of solder paste and computation times measurements indicate that it is roughly 20 times faster.

3D profile measurement of work-piece by non-contact optical methods has been studied extensively because of its importance in the automated manufacturing processes and quality control of components. In this paper, a projection method and its calibration algorithm of parallel projection means for 3D profile measurement system was presented. The proposed method used the pin-hole theory. An arc light which was assumed to be a point light source was positioned in the focal point of a parabolic mirror. After it was reflected by the parabolic mirror, uniform parallel light beams were projected. Using alignment collimator and telescope, the best positions of all of the optical elements in the system can be adjusted. Parameters of CCD lens, image center, arc light source and their relative positional relationship were also calibrated. This ensures the overall accuracy of the projection system. For most of the structured light optical methods, the size and shape of the dot laser beam or the length and width of a line laser beam of the projected slits were functions of the measurement range. A lot of efforts and caution have been conducted int he calibration process and mathematical manipulations are required to assure the measurement accuracy. The proposed parallel projection beam method eliminates above mentioned difficulty. It could be a robust and efficient non-contact optical method for the measurement of 3D profile.

The paper has provided an optoelectronic method that used a four-quad detector to detect the property of common axis of active-following axis. On the basis of careful consideration, the paper determines the working principle and designs the mathematical model of the whole system. It is shown by computer simulation that this method is feasible. Compared to conventional mechanic micrometer method, it has the properties of reliability, precision and accuracy.

In this paper, the principle of structured light 3D vision is briefly introduced and the method of establishing its general mathematical model is given in detail. Applying perspective, translation and rotation transforms in homogeneous coordinate system to structured light 3D vision, the model possesses the advantages of high accuracy, great simplicity and high generality. This gives the conveniences on reconstructing the surface coordinate of an object.

Two new and simple methods for measuring the 3D rigid body line displacements and 3D rigid body angle displacements are proposed. And at the same time, two laser diodes and two new CMOS image sensors are used as light sources and photodetectors, respectively. Moreover, the experimental results are presented, which demonstrate the new methods have high accuracy, high processing speed, high reliability, and are easily realized.

This paper focuses on realizing the three important aspects of bar code scanner: generating a high quality scanning light beam, acquiring a fairly even distribution characteristic of light collection, achieving a low signal dynamic range over a large depth of field. To do this, we analyze the spatial distribution and propagation characteristics of scanning laser beam, the vignetting characteristic of optical collection system and their respective optimal design; propose a novel optical automatic gain control method to attain a constant collection over a large working depth.

In this paper, a system for measuring perpendicularity and parallelism derivation using a laser diode fiber aligned beam and CCD detector is described. A stable aligned laser diode beam is used to form datum planes by rotating scanner equipped with pentagonal prism. Using a linear array CCD detector as the sensing probe, the system can detect the deviation of height related to the datum plane directly and absolutely. The experiment result is shown in the paper.

A high-speed automatic agricultural produce grading and sorting system using color CCD and new color identification algorithm has been developed. In a typical application, the system can sort almonds into tow output grades according to their color. Almonds ar rich in 18 kinds of amino acids and 13 kinds of micro minerals and vitamins and can be made into almond drink. In order to ensure the drink quality, almonds must be sorted carefully before being made into a drink. Using this system, almonds can be sorted into two grades: up to grade and below grade almonds or foreign materials. A color CCD inspects the almonds passing on a conveyor of rotating rollers, a color identification algorithm grades almonds and distinguishes foreign materials from almonds. Employing an elaborately designed mechanism, the below grade almonds and foreign materials can be removed effectively from the raw almonds. This system can be easily adapted for inspecting and sorting other kinds of agricultural produce such as peanuts, beans tomatoes and so on.

A new high-speed computer color testing and matching system with the receptor of photoelectronic diode array is presented in this paper. The system is used in automatic inspection of dyed textiles not only off-line for the laboratory, but also on-line for dye shop.

Scanning mirror uniformity directly effects the exposure area of exposure sample in the chamber of soft x-ray lithography beamline and station. The exposure uniformity control system consists of a scanning mirror, an in-situ Moire fringe grating system, a coupling glass fiber and a silicon photodiode, a high speed A/D interface and on-line microcomputer. Our main study is how to measure uniformity signal finest and how to transfer signal data into computer on-line fast enough. The required driving variation is programmed by a single piece computer which communicates with an IBM PC computer used to control main systems of lithography beamline. The system works so well in HESYRL. But the exposure uniformity is relative to stepping motor vibration frequency. it is not so easy to find a good frequency to get exposure uniformity as best as the system does. In this paper we will discuss on-line real control system in lithography beamline and its basic character. Some results analyzed and new ideas will have more potential prospects on industry application and other applications.

In this article, the basic principle and the key technique of an optoelectronic type of electric current transducer system are discussed. The system is used to measure the primary current in a high-voltage and large-capacity power system.It has many advantages such as wide current range, high precision, simple insulation structure and high price- performance ratio. The signals of electric current at the high-voltage side are converted to digital signals, which are coded according to a special mode and transmitted with a special baud rate. In order to ensure the measuring accuracy, a fast quasi-synchronous weighting algorithm is adopted to do data processing at the low-voltage side.

This paper presents a new phase unwrapping algorithm to deal with the problem of phase restoration from an interferogram that is in presence of both high-level random noise and segmented discontinuity. The algorithm is based on a composite template matching to simultaneously identify unreasonable phase jumps caused by speckle noise and segmented discontinuities such as holes and borders int he wrapped phase map. Examples unwrap with the interferograms generated by the computer and real speckle fringe patterns taken from double-pulsed speckle interferometer are included to show that the technique is efficient and simple to implement.

This project was to calculate the effect of illumination based on optical principles, structure of bulb and reflectors, and refracting unit of optical lens. This software can make designers clear of what the results are. Thus the modification time can be reduced when testing and cost will be saved. So far, a comprehensive software for simulative calculating and display of illumination of luminaire has been developed initially. This article discusses the basic principle and mathematic models of programming with respect to the structure of bulb, reflectors and optical lenses, simulation calculation and display of illumination. The article also introduces the function of the program and the results of calculation.

The maximum rang finding ability of laser range finder (LRF) is greatly influenced by various factors under field conditions, and these factors are changing constantly. In this paper, the advantages and shortcomings of traditional test method 'dissipated light power ratio method' through field object target are analyzed. A computerized instrument is developed, this instrument has no influence with field environment and characteristics of targets, it is simple, effective, accurate and quantitative to test comprehensive ability of range measurement which LRF system itself has. This paper introduces optimal formulas by use of computerized instrument to estimate the measuring rang of LRF, studied the theory of equations of measuring range by laser, and made a breakthrough of test method at program control of time-delay simulating space range and transmission and receiving of LRF under field conditions. This computerized test instrument has highly practical application and theoretical guiding meaning in demarcating checking and accepting of product produced by factories.

Speckle photography has been used to measure the instantaneous deformation of gear teeth when gears are rotating under load. Double exposure photograms are recorded with a pulse ruby laser, and correlation fringes formed by spatial filtering of the developed film. A new technique is presented for eliminating the influence of diffraction halo. A method reducing the noise level is proposed. As a conclusion, the values of gear tooth dynamic deformation are a little larger than those of the analytical calculated by finite element method in static condition, but the regulation both the measurement results and analytical ones is in good agreement.

An essential part of a machining system in the unmanned flexible manufacturing system, is the ability to automatically change out tools that are worn or damaged. An optoelectronic method for in situ monitoring of the flank wear and breakage of cutting tools is presented. A flank wear estimation system is implemented in a laboratory environment, and its performance is evaluated through turning experiments. The flank wear model parameters that need to be known a priori are determined through several preliminary experiments, or from data available in the literature. The resulting cutting conditions are typical of those used in finishing cutting operations. Through time and amplitude domain analysis of the cutting tool wear states and breakage states, it is found that the original signal digital specificity (sigma) ²_x and the self correlation coefficient (rho) (m) can reflect the change regularity of the cutting tool wear and break are determined, but which is not enough due to the complexity of the wear and break procedure of cutting tools. Time series analysis and frequency spectrum analysis will be carried out, which will be described in the later papers.

A new Chinese patent 'micropore imager of industrial television supervision' is introduced in this paper. Three ways of transmission is compared. The author invent a flame- proof 'micropore imager' to image close quarters high- temperature at normal temperature area, obtain 'first image' then use television-camera to shoot the image into television system, transmit it to supervision center. The micropore imager is based on the principle of small aperture imaging and it applies image sharpening technology to make image fitting for supervision requirements, it also attaches accessories to prevent blocking. This method has been proved by doing experiments on boilers in power station.

To guideways of machine tools, precision instruments and rectilinear motion. 3D straightness instrument which uses the electronic spirit level and applies the principle of photoelectric automatic collimation. And it can determine the 3D straightness precision at the same time. The 2D electronic spirit level is an nonlinear sensor and the readings of the two dimensions are not completely independent of each other. Methods are given in this paper to resolve these problems.

A new concept for roughness measurement is presented in this paper. The new concept is the mean surface that describes the summation of the shape, error and waviness of a profile surface measured by the interferometric microscope. The mean surface is fitted by the Zernike polynomials in a least squares sense. When the mean surface is subtracted from the profile data, the roughness can be calculated. The numerical simulations show that the accuracy is enough high.

A passive IR remote sensing system is developed. This system works in the wavelength range of 8-12 micrometers with high sensitivity. The spectra of some pollution clouds have been obtained from the field test. The pattern recognition and a series of preprocessing techniques are also studied. Using the spectra of specified materials which one are interested in, if the pattern recognition training is carried out, then this chemical compound could be qualitatively auto- discriminated in the coming field test.

In this paper we proposed a scheme of on-line measurement of screw-thread steel bar in real-time, which its operation principle is discussed in detail. With the aid of real-time, we have taken the following procedures: 1) By means of self- adjusting threshold voltage-level, the binary image is obtained through hardware. 2) By using run-length coding, the binary image is compressed furthermore and the sum of data to be processed is greatly reduced. 3) A special organization of the coding data, as well as a flexible employment of a novel dual-port RAM, make the CPU of computer capable of reading and saving the data directly from the storage buffer.

In the steel-plates' shearing course of steel and iron plants, the industrial dimensions such as the length and width of the steel-plates must be measured on-line with the control of computer and the shearing position is guided precisely and dynamically. The paper presents the method of measuring the geometrical dimensions with face lattice CCD cameras, then taking measuring and shearing of steel plates as an example. The composition and scheme of the measuring system of steel plates are given in detail.

In this report, an optoelectronics instrument is introduced, in which the technology of laser alignment, the technology of computer image identification, and the principle of optical triangulation are used to inspect the contour and the internal surface quality of rifling in artillery barrel with real-time and automatically. This instrument is composed of laser aligning system, optical triangulation system, CCD camera system, computer image processing and identification system and computer-controlled system, the photoelectric targets of the caliber gauging system, of the CCD camera system and of laser aligning system, are all fixed in the chamber of the cutter of the boring tool, and they compose the photoelectric probe. When the boring tool bores the barrel, the light coming from the semiconductor laser which is located in the photoelectric probe, is reflected by the internal surface of the barrel and then received by 1D CCD. By the aid of optical triangulation operation, the radius of the rifling can be obtained, in the mean time, the image information of internal surface of the barrel, which is obtained by CCD is fed to be processed by computer image processing and identification system, and then the classified results can be given. The magnitude of deviation of the boring cutter from its ideal boring line, is provided by the laser aligning system with real time, the feedback system can revise the position of the boring tool whenever necessary. The caliber gauging precision of this instrument is +/- 0.005mm.

A heterodyne interferometric system is presented. It is characterized by surface selectivity, high resolution and time saving measurement by using a short coherence length light source and a position sensitive detector. The tilt of a surface under test is converted into the deviation of a light spot from a fiducial point and measured by the position sensitive detector. With such a system an angular resolution of 0.1 second is obtainable.

Due to the demand of shorter cycle times of measurement tasks, CMMs are expected to be used at high speeds. In such measuring process dynamic errors will have greater influence on the accuracy. The dynamic error properties should by analyzed in this case. Considering the analysis of a specific CMM, a dynamic error assessment model is established in this paper. The major deflections at the probe position due to accelerations are obtained by using the finite element calculations and the error data fitting polynomials of three coordinates are established. With a laser interferometer, the dynamic rotation errors of the CMM at the probe position are measured. By comparing the results of the measured dynamic errors using the laser interferometer and the ones obtained by the errors fitting polynomials, it is shown that dynamic error compensation for a specific CMM is possible in a certain degree.

This paper presents a new 2D measuring system-profile measurement of extruding tire tread by laser. It includes the thickness measurement of extruding tire tread by laser and the width measurement of extruding tire tread using Moire Fringe. The system has been applied to process line of extruding tire tread. Two measuring results have been obtained. One is a standard profile picture of extruding tire tread including seven measuring values. Another one is a series of thickness and width values. When the scanning speed < 100mm/sec and total width < 800mm. The measuring errors of width < +/- 0.5mm. While the thickness range is < 40mm. The measuring errors of thickness < +/- 0.1mm.

The theoretical and experimental studies of pulse-heating infrared thermography non-destructive testing technique are presented in this paper. Our home-made pulse-heating infrared thermography non-destructive testing system is introduced. The system mainly consists of an infrared thermal imager and pulse-heating sources. The infrared thermal imager can acquire images continuously at the speed of 25 frames per second. The imaging and analyzing processes are controlled by a computer. The special software was designed for this system. In order to get a high inspection resolution, the heating source must be an adequately fast pulse. In our system, two flash-tubes are used as pulse- heating sources to launch thermal waves on the target. About 7kj energy is discharged through two xenon tubes each time. Steel, aluminum and plastics testing samples are inspected by using this system. The inspection results are given. The advantages of this technique are no physical contact, large area, fast and quantitative non-destructive testing.

A new untouchable measurement method, i.e. displacement sensing with laser interference is presented in this paper. This method is used for real-time and continuous measurement of displacement and vibration for engineering structures, and has the advantages of wide measurement adjusting range, high stability of interference fringes and low sensibility to environment. In this paper, the principle of the method is described, and the measuring results of typical structures are given. The prospects of the applications in measuring displacement and vibration for engineering structures are also discussed.

Phase measuring technique has been widely used in optical precision inspection for its extraordinary advantage. We use the phase-measuring technique and design a practical instrument for measuring 360 degrees profile of 3D object. A novel method that can realize profile detection with higher speed and lower cost is proposed. Phase unwrapping algorithm based on the second order differentiation is developed. A complete 3D shape is reconstructed from a series of line- section profiles corresponding to discrete angular position of the object. The profile-jointing procedure is only related with two fixed parameters and coordination transformation.

The rotating mirror high-speed camera control system is an important part of the camera. Chip microprocessor technique is the core of this system. By means of software combined with hardware, the camera can automatically finish the whole high-speed photograph control. This paper introduces its structure operating principle methods and specifications.

An improved signal processing method for laser interferometer is investigated to measure the radius of large precision centrifuge. Based on phase and integer periodic phase measurement, it not only makes the resolution up to 1 in 2000 of a wavelength, but also enlarges the range of the interferometer. The absolute radius measurement of the 5m centrifuge with the accuracy of +/- 3.4micrometers is achieved.

The paper shows how the laser measurement method may be applied in mechanical engineering. Double-exposure speckle photography is used to measure the dynamic deformation of spur gear tooth. A series of experiments of gears with different speed, load and accuracy have been done and double-exposure speckle patterns at different meshing positions have been shot. The dynamic information of spur gear tooth during the whole meshing procedure is obtained by means of automatic image processing.

The principle and method of straightness curvature measurement by using tangent method and the creation of its theoretical made is introduced in this paper, and the measurement system made up of position-sensitive-device, auxiliary electrical circuit and personal computer is generalized also, the error source of this system is provided and the way to improve precision is discussed as well. At the end of this paper the experiment results are given out. The results proved that this system is high- efficient, high-reliable and high-precise, and can be applied in the measurement of certain kinds of shape and position error.

In this paper, the principle using linear CCD to measure geometrical dimension is introduced, and the edge distribution of the light intensity under the practical noncoherent illumination and the diffraction light on the straight flange is theoretically analyzed. It is suggested that the discrete image signal output of CCD is smoothed and the zero-passing moment of the second derivative of the smoothed signal is detected to obtain the point of inflection on the light intensity distribution. An experimental installation has been designed. it is stated that the experiment can carry the resolution in one-fourth of a pixel size, for example, the resolution of a TCD132D image sensor with the pixel distance of 14micrometers can carry about 3.6micrometers .

It is very complicated to determining the speed of object in random motion. A special instrument is described in this paper in order to detecting the object's speed in random motion. There is a column of photoelectric detecting units in the instrument. The speed and the position of the spherical object center in random motion in the vertical photoelectric detecting plane can be derived from the data gotten by inspecting of the photoelectric devices.

Moire topography has been used as a noncontact method for grasping the 3D shapes of objects, but it is not easy to judge whether the surface is convex or concave from one moire picture. It is difficult for automatic measurement. In this paper, a new computer-based technique for automatic 3D shape measurement, tracking of carrier coded fringe pattern is proposed. It can accomplish fully automatic distinction between a depression and an elevation of the object shape. Therefore, it can accomplish automatic measurement. Validity of this proposal is experimentally verified.

A new technique of the fringe analysis is proposed to automatically measure the 3D object shape. A grating pattern is projected onto an object, and the grating pattern deforms in accordance with the 3D object. This deformed grating image is analyzed by means of subfringe integration algorithm, the phase distribution and the object shape are given at every pixel at measured object. In contrast to FOurier transform profilometry (FTP), this technique processes fringe in its spatial domain instead of the frequency domain, so it is faster and more convenient than FTP.

A new method of geometrical aberration measurement for an optical system with large aperture is proposed by using a series of holographic gratings, which are linearly recorded with 0 and +/- 1 order diffractions or nonlinearly recorded with more order diffractions. According to the aberration property (symmetry or unsymmetry) of the optical system undertest, one or two dimension gratings can be used. Some experimental results are given and related problems are discussed.

This paper is concerned with an application of a multilayer feedforward neural network for the vision detection of industrial pictures, and introduces a high characteristics image processing and recognizing system which can be used for real-time testing blemishes, streaks and cracks, etc. on the inner walls of high-accuracy pipes. To take full advantage of the functions of the artificial neural network, such as the information distributed memory, large scale self-adapting parallel processing, high fault-tolerance ability, this system uses a multilayer perceptron as a regular detector to extract features of the images to be inspected and classify them.

This paper introduces a novel method of non-contact dynamic measurement of liquid level position with an instance of the monitoring system of liquid-steel level position; presents an important aspect to improve the system sensitivity and stability, and explores the system measurement theory and the resolution speed.

The veiling glare of an optical system is the major specification for appraising its image quality. Black-spot method for measuring the veiling glare is a currently common-used technique. Instability in the power supply and devices directly affects the measuring accuracy. Comparing the two beams from a same source of light, using a bridge differential circuit, displaying the balance with a galvanometer, and taking the resistance with a precision resistance box, we can calculate the veiling glare index. It is proved by the calculation and experiments that the measuring accuracy is as high as 10^-4.

Up to now, the measurement of the contact pattern of gears is made by vision. This paper introduces an automatic measuring device for contact pattern of gears based on photoelectric scanning and discusses the measuring principle of the device briefly.

The kinematics of deformation of the object to be studied is combined with the formation of this holographic image by using the tensor analysis as a mathematical means. A relational expression for the surface and interior strain of a diffused object versus its rotation measurement is derived from the optical-path difference. With the ZFC method of a single hologram, a herculite container, as an experiment, is measured. The experimental results are in agreement with a strain gage.

Utilizing micro-optics components, a new technique for measuring the properties of optical system is developed in this paper. The micro-optics components have been composed of a microlens array and a matched array of pinholes. Passing through the micro-optics array components, the light beam projects into the tested optical system, and is detected as a power spectrum by CCD plane array at last. By processing and analyzing the information from CCD detector, some main properties of tested optical system can be obtained. The experimental results are satisfactory due to the 2D plane symmetry and high power efficiency of the micro-optics array components.

A new measurement of the curved surface has been developed. The paper provides an effective, real time and dynamic optical measurement which is suitable for the measurement of airfoil, turbine blade, car and tank's curved surface. The system consists of a laser probe, a charge couple device (CCD), a computer, three servomotors. Consideration is also given to the design of the laser probe and CCD driving circuit.

A new kind of analytics method based on laser heterodyne interferometer to achieve high lateral resolution is presented. This system needs no special platform and the size of the laser beam is several micron. The Gaussian distribution theory and the phase sum theory of laser beam are used to set up mathematics model for measuring the edge of micrograph. Modern multivariable regression techniques are applied to estimate the edge position of step. The estimation accuracy of this method is only related to measurement accuracy of measured variable. The lateral positioning accuracy of this system can reach the order of 0.1micrometers . On the other hand, the errors caused by the frequency mixing of the laser beam of the common-path optical system are also analyzed. The calculated curves of the errors are given and the method to reduce these phase errors is also introduced.

This presented paper describes a high-precision goniometer system with a ring laser gyro (RLG). The principle of the goniometer is introduced. The key techniques for improving the measuring accuracy are analyzed. As the central element of the goniometer, RLG is investigated, including its error items, such as scalefactor, bias and random walk coefficient. The experimental results are provided.

A new non-contact method for determination of elastic constants with laser ultrasonic waves is presented. A confocal Fabry-Perot interferometer and whole non-contact measure system have been developed for detecting laser- generated ultrasound on rough surfaces. The elastic constants are determined by measured velocities of longitudinal and Rayleigh wave. The experimental results demonstrate that laser ultrasonic techniques are practical and effective.

When the phase of interference signals is directly subdivided, nonlinear errors, some of which are periodic, will be produced due to the improper assembly and defects of optical elements. In order to compensate for such errors, this paper puts forward a principle of compensation and introduces a device including two (lambda) /4 wave plates or two orthogonal axes and a V-shaped double-plate splitter, by which a beam is divided into two. This device is theoretically proved int his paper.

The phase compensation method presented by A. Lien is a precise and convenient tool to measure the cell gap of filed twist nematic liquid crystal cells. But in the paper the equations which were used to calculate the thickness of LC layer are not enough to distinguish the two phase difference which does correspond to different cell gap. In this paper, the conditional equations were given and the factors affected the accuracy of phase compensation were discussed.

In this paper, a new method for edge location-laser half- focus edge checkout is introduced. To ensure high precision of the edge checkout, many comprehensive techniques such as self adaptive tracking for compensation, laser modulating and compensating for modulated amplitude, fixed-point sampling technique by differentiation and fine dividing technique for the step of step motor, etc., have been used. A theoretical model for the edge checkout using laser half- focus and the result of computer simulating are also given. In addition, a system of measuring diameter adopting this method is described. The measuring uncertainty 2 (sigma) of the system is within 3 micrometers .

In this paper, Fourier transform evaluation of fringe phase is proposed for moire deflectometry. Using this method, high-precision and automatic measurement for axisymmetric gas temperature field has been accomplished.

Nonlinear control of double Fabry-Perot interferometer (DFPI) has been investigated. A parallel subsystem of hardware simulation for compensating the influences of atmosphere and other shifts was suggested by author in 1982 but the nonlinear control theoretical analysis and how to improve the performance of DFPI are further discussed in this paper.

This paper states the cam's data processing algorithm in detail in high accurate camshaft measurement system. It contains: 1) using minimum error of curve symmetry to seek the center position of the key slot; 2) Calculating the minimum error by cam's curve in theory to search top area; 3) According to cam's tolerance E(i) function and minimum angle error at cam top, seeking the best position of cam top and getting the best angle value and error curve. The algorithm is suitable for measuring all kinds of symmetry or asymmetry cam, and plain push-rod or spherical push-rod cam, for example, bus camshaft, car camshaft, motor camshaft, etc. Using the algorithm, high accuracy measurement can be achieved.

This article intends to talk about the characteristics of a kind of intelligent optical measuring equipment and the technical method to realize its intellectualization. Meanwhile, in the following three aspects, this article points out the prominent difference between intelligent optical equipment and conventional optical measuring equipment. 1) Intelligent optical measuring equipment has the ability to compensate the errors from part or subassembly of system itself. 2) Intelligent optical measuring equipment has self-adaptation ability to changes of environment. 3) Intelligent optical measuring equipment has the ability to analyze and determine fault.

The characteristics of a laser-scanned measuring system relate to many factors such as laser, optics, electronics and fine mechanics, etc. The mechanism of the interaction among various factors is much complex, too. Based on the research work for many years, authors of the paper made systematical and theoretical analysis for the characteristics of the laser optics system, photoelectric converting electronics systems and optics and mechanics systems of the laser-scanned measuring system, gave relatively mathematical expressions, established the mathematical model of the system.

The relationship of position and dimension with the parameters of optical system as well as the included angle relationship of one dimension charge coupled devices (CCD) with the optical axis were derived by using optical principles, they provided theoretical basis for design of the system. On the basis of the above, a laser position and dimension on-line inspection system was introduced in the paper. In the system, He-Ne laser was taken as light source and CCD as photoelectric position sensor. The working principle, overall structure and electronic system for photoelectric information processing of the system were discussed specially. The measuring precision of the system was verified by experiment.

The basic principle and overall structure of a non-contact steel products dynamic on-line inspection instrument was described in the paper. During production of rolled steel, it performs auto-measurement of diameter and ellipticity of all kinds of wires, rods and steel pipes in red-hot and fast-moving situations, having high speed and high precision. Formulae of ellipticity error for rolled steel were derived and analyzed. The computer real-time data processing and control system were discussed in detail.

In this paper, we analyze the functional theory of infrared dynamic automatic inspecting technology, and describe the features of this system using this technology.

This paper raises a photoelectric integrated flexible synthetical measuring technology according to the inspecting requirements of a flexible manufacturing system, which is suitable for measuring the size, formal error and positional error of all kinds of worked parts such as rotating body, case body and plate with a high accuracy, high efficiency and non-contact and on-line.

This paper describes an automatic non-contact measuring method for the formal and positional errors of the flywheel and gear-ring assembly of an automobile. It emphasizes on the overall structure and working principles of the measuring machine, and theoretically analyzes its errors.

This paper introduces a non-contact three-coordinate measuring machine using laser inspecting technology, and focuses on the discussion about the working principles of the laser probe and related theories.

The paper describes the basic principle and overall structure of a semiconductor laser-scanned multi-functional on-line inspection system, which is used to realize high speed and high accuracy, non-contact and on-line inspection for rotating body type of parts and various formal and positional errors by using semiconductor laser-scanned principle. It mainly discusses the following three aspects: first, laser-scanned emitting system composed of a semiconductor laser, a laser power source, a scanner and a scanning optical system; secondary, a laser-scanned receiving system composed of a receiving optical system and an optoelectronic converting electronic system; thirdly, a master controlling system with micro-controller as the core, real-time control and data processing system.

This paper is concerned with the discussion of the application of the optics and the systematic designs involved by means of the tensor A B C D law and the semiconductor laser.

This paper discusses the working principle of a photoelectric auto-inspecting system which is used to measure three formal and positional errors of a workpiece at the same time, design of the fine mechanical system and accuracy analysis. This system is very suitable for dynamic and non-contact measurement and has a very good developing future.

This paper describes a photoelectric non-contact surface displacement measuring system using reflection light displacement differentiate method. In this system light source is semiconductor laser, photoelectric receiver is semiconductor position sensor device, using transverse photoelectromotive force effect in the PSD's p-n junction to detect irradiates position of incident light point. In has accurate, fast and harmless characteristics. In order to improve measurement accuracy, a microprocessor is added into this system to complete digital filter, linear correcting and statistic processing in the course of measurement. Especially, this paper introduces stabilizing electronically light, extracting PSD signals and processing data with computer, etc in detail.

In machining rotating body parts, which make up a large ratio among all parts to be worked, the radial size and axial size of any locations must be inspected. The photo- electronic 2D auto-inspecting system for rotating body parts made by us has been already used in a factory. A laser- scanned measuring system and a grating displacement measuring system have been adopted to measure the diameter and the axial size of each section respectively. This system can also be used to measure various formal and positional errors, and shapes of rotating body pats. This paper mainly describes the working principles, some problems related to the design and accuracy analysis.

This paper describes the principle and the optical arrangement of three kinds of bidirectional shearing interferometer for collimation testing. The interference fringes expression formula and the collimation testing accuracy are also given in this paper. The results obtained show that the testing accuracy is higher.

It is usually difficult to reach an expected testing accuracy using general methods to measure the scanning prism. So this paper puts forward a new method of testing the angular error and pyramidal error of the scanning prism by the Haidinger interference. The relative formulas are deduced, the testing method and instrument are presented in the paper. We also analyzed the testing accuracy. The actual testing accuracy of this method is about 0.5 inches. It is one of the best methods with high accuracy at present. In addition, this method can be used to estimate the surface deviation according to the interferogram. This method belongs to common path interference. The fringe is stable and reliable.

A simple photoelectric system is devised in this essay. An optimum diaphragm is chosen through measuring the optical transfer function of double-ringed diaphram in different dimension. In this way, it is proved that the quality of speckle pattern diffraction halos can be increased and a complex calculation can be avoided. The calculation and the photos provided here prove the reliability of the measurement.

This paper deals with a laser scanning device used in a space-encoding rangefinder. At first the principle of space- encoding is introduced. And then the error expressions of the rangefinder are given on the basis of establishing its mathematical model. Furthermore are deduced the functional relations between the measurement errors and parameters of the laser scanning device as well as errors of the parameters. At last approaches to reduce the measurement errors caused by the laser scanning device are found out according to the above said error expressions and functional relations.

A method based on total internal reflection is presented for determining the refractive index of materials. A focused light beam and a semicyclindrical lens in contact with materials are used in the experimental apparatus. The dependence of the internal reflective intensity or reflectivity on the angle of incidence is measured by a photodetector, e.g. linear CCD camera. The critical angle and therefore the refractive index can be obtained from the spacial distribution of internal reflective light. If a monochrometer is chosen as the light source, the chromatic dispersion curve of materials can be determined directly and quickly. The simple method can easily be controlled by computer techniques and applied to both tiny transparent and opaque samples whether they are solid or liquid. The several experimental results have shown that the method is reliable and very useful. It will play a role in many areas relative to the refractive index.

Now days, the most popular commercial non-contact measurement system uses the triangulation method. To obtain the accurate and quick results of measurement system, the calibration of the system is a must. In this paper, the ANN technology has been used along with laser scanning measurement systems. The image of the given object is measured with the help of a CCD camera and is fed as the input layer to the neural network, whereas the geometrical data of the object surface is the output layer. If the network is properly trained, it will provide the accurate surface fitting. The perceptron model has been adopted and trained by using an improved back-propagation algorithm. The results of the experiments have concluded the higher accuracy of the proposed measurement technique, as well as it is an easy and fast method. It has also eliminated the influence of lens aberration and other factors.

This paper will discuss how to improve the dividing quality of radial grating and introduce the method which corrects the dividing errors of radial gratin automatically. Through analyzing the dividing errors of radial grating, the changing regulation of main error sources can be seen and the mathematical formula is also given. Photoelectric device and microcomputer are utilized to control the special transmission device which makes radial grating rotate an additional angle. The additional rotation of grating will counteracts the dividing errors of radial grating.

The methods of vision recognition, position and orientation in a flexible automatic coordinate measuring system (FACMS), which is formed by integrating computer vision and computer aided inspection planning with CNC-coordinate measuring machine, are discussed in this paper. The working principle and working process of multiple orientation run length coding, the vision recognition method used in the FACMS, are presented elaborately. Based on the moment of inertia of the binary image of workpiece, the methods of position and orientation are presented here. The research work in this paper shows that it is feasible and effective to integrate computer vision with measuring systems, so as to increase their flexibility and automation.

An interferometric method is used to evaluate the refractive index deviation in the infrared materials. The deformations of the surfaces on the sample are precisely measured by phase shifting interferometer working at 0.6328 micrometers and the errors introduced by the surface deformations are removed from the results. The accuracy of this method reaches the order of 10^-5.

This paper describes theory and performance of a self- developed IR phase-shifting digital interferometer which uses a CO₂ laser as light source, this instrument comprises of a Fizeau interferometer whose aperture reaches (Phi) 250mm with accuracy better than (lambda) /50, and a Twyman spherical interferometer. Using piezoelectric transducer to shift reference mirror, phase measurement interferometry can be carried out as well as the temperature modulation of PEV target. A series of software packages used as wavefront fitting, image quality evaluation, are incorporated into the instrument. With the help of microcomputer, this interferometric system can measure refractive-index homogeneity of IR transmitting materials, wavefront error of IR optical system and surface quality of rough surface etc., which can all be shown by detailed data of optical path difference, vivid 2D contour and 3D surface.

Up to now, as large as seven times of Rayleigh-range or more is needed in measuring the far-field Gaussian beam divergency. This method is very inconvenient for the determination of the output beam divergency of the industrial product such as He-Ne lasers and the measuring unit will occupy a large space. The measurement and the measuring accuracy will be greatly influenced by the environment. Application of the Ronchi ruling to the measurement of far-field divergency of Gaussian beam in near-field is analyzed in the paper. The theoretical research and the experiments show that this measuring method is convenient in industrial application. The measuring system consists of a precision mechanical unit which scans Gaussian beam with a microdisplaced Ronchi ruling, a signal sampling system, a single-chip microcomputer data processing system and an electronic unit with microprinter output. The characteristics of the system is stable and the repeatability errors of the system are low. The spot size and far-field divergency of visible Gaussian laser beam can be measured with the system.

By means of two improved methods on particle field measurement in flame flow, the parameters of particle are obtained. The influences of high brightness of flame and severe disturbance of uneven density field are overcome.

A comprehensive test system with unitary light source is described, which is a combination structure. The system can provide the whole function of formerly several common instruments for the test of image tubes. It can test the light quantum parameters, such as photo cathode sensitivity, luminance gain, automatic brightness control specification, equivalent background input, signal-to-noise ratio and output brightness uniformity, and geometry parameters, such as resolution, distortion, image alignment and magnification. The measuring uncertainty of the parameters is 1.7 percent to approximately 3.7 percent. The total uncertainty of system is 4.6 percent. On the basis of the structure designed, the system can be developed to an automatic instrument for testing the optical-electric performance of low-level-light image intensifiers.

This article introduces a kind of structure for realizing CCD infrared three-color temperature sensor, which consists of narrow and parallel light, CCD components with line matrix, and infrared three-color filter. This method can increase the symmetry and instant function for gathering signal of original radiation light because of the characteristics of CCD components. According to theory of heat radiation, real temperature of the body can be measured directly when technology of computer gathering and handling is used.

In this paper, we introduce a new type of multi- piezoelectric 2D light scanner and analyze the scanner's principle, characteristics of construction and property.

The problem of propagation of (2 + 1) dimensional optical pulse with time-space asymmetry in a saturable Kerr medium is discussed. That pseudo-momentum and energy of the optical pulse keep conservative along propagation is obtained by using variational method. The impacts of initial asymmetry, saturable strength and coupling strength on pulse width, beam width are studied by using numerical method.

The analogy between dispersive pulse propagation in time and spacial diffraction or focusing has been known and discussed for many years. In this paper, we corrected the choice of parameters and defined the p parameter, analogous to q parameter in space domain again, with p parameter we analyzed the Gaussian light pulse propagation in dispersive fiber and the dispersion compensation of light pulse with stimulated Raman scattering amplifier. In the end, we predicted that the source of the most effective compensation is from the broadening pulse with suitable changing the phase.

The symmetric two beams are first used to irradiate a single laser angle sensor overlapping and the reflected films are plated on the reflecting plane of LAS. It breaks through the limitation of the measured angle area limited by the full internal-reflection angles. This method makes the measured angle area to be increased to 140 degrees in the static state and 76 degrees in the dynamic state, the experimental errors of angle measurement are reduced to 0.007 degrees. The output of measured angles is displayed as numbers and printed by a computer.

The paper presents tow kinds of new optical methods for measuring electric power. They are respectively called indirect optical method for measuring electric power and direct optical method for measuring electric power. The principles and signal processing technique of the two kinds of methods are discussed comprehensively and systematically. The study shows that the two kinds of methods can be used to measure the electric power when the current is large and/or the voltage is high.

With the method of JOnes matrix, formulas for intensity of transmitted light through the optical analyzer of various composition of electro-optical effect with magneto-optical effect are derived. The results show that the output beam from the analyzer carriers information on current, voltage, active power and apparent power. We can use the electric filter circuit to pick out this information for measuring active power, apparent power etc. The paper discusses what quantities measured when the analyzer set on certain definite values, and points out the optimum selection for various measurements.

Laser measuring is one of the main methods in precision measuring. Two-frequency laser measuring using Zeeman effect is a usual measuring method, which has better anti-jamming characteristic and higher measuring accuracy. But because of higher cost and lower motion velocity of the measured workpiece, its application is restricted. Acousto-optical modulated laser heterodyne measuring which has many advantages is researched and discussed in theory in this paper. And the realization of the measuring instrument is studied carefully. The method shows a new way for measuring the displacement with lower cost and higher accuracy.

Based on the statistical properties of laser speckle, the response for laser speckle passing through a linear shift- invariant system is studied. This paper presents a method for testing the modulation transfer function (MTF) of charge-coupled devices below the Nyquist frequency. A new scattering microcrystalline glass material generates laser speckle. The instrument is designed and test results show that this technique is a variable MTF measurement approach. The difference of the results of each test is within 0.03.

For ultra fine particles to be manufactured, vibration mill is one of the most effective machines whose dynamics is the key factor for the efficiency of the mill and the quality of the product and the foundation of the analysis of structural response. Different from the researches presented up to now, this paper deals with the nonlinear dynamics of the high efficiency vibration mill with steel rods as grinding media which has an amplitude up to 15mm and a vibrating strength of 15g. Because it is difficult to measure the system signals, the high-speed cinematography is introduced. By this means it is found that the principal impact is generated between the machine body and the mass center of the grinding media during the operation whose frequency is equal to that of the exciting force. The super and subharmonic vibration components are also observed. The results mentioned above are proved by the frequency spectrum analysis with other method. It can be concluded that high- speed cinematography is efficient and reliable for the research of complex dynamic systems.

Particle sizing by laser diffraction provides a prospective method for real-time detection of weight and size information of coal mine dust. Quickness, accuracy and ability to measure total and respirable dust weighs are some of the basic requirements for inversion method of the coal mine dust transducer. This paper presents a quick inversion scheme that can be referred to as pattern recognition of laser diffraction field. Single-chip computer system simulation results show that this method not only furnishes excellent estimates of both total and respirable dust weights in a very short time but also features high anti- noise ability and stability.

In this paper, we introduce a new method to inspect the soft and smooth surface, especially the corneal topography. The method is based on the fact that smooth surfaces have the property of reflecting light. Special-shaped gratings are used as projecting device, that is, different grating for different inspected object, according to the topographic condition. For example, a grating with the form of a series of concentric circular rings is good for corneal topography inspection. When the image which contains the topographic information of the object being tested is reflected, it is recorded by a CCD camera. Then the 2D image obtained is processed and calculated by a computer to make out a 3D profile of the surface. This article emphatically reckons a new algorithm which can deduce the corneal topography.