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Issue 5 ， 2003
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Present state and perspectives of micromachined inertial sensors
Abstract：A review is given to the present state of micromachined inertial sensor-micro-accelerometers and micro-gyro. These sensors have a number of significant advantages, such as lower cost, smaller form factor and lower power consumption. Their manufacturing process, transfer mechanism, control system and interface technique are described in detail.Keywords：Micromachine;inertial sensor;accelerometer;gyro- 37
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Published：2020-08-12 -
Development of cell injection pipette puller
Abstract：In order to be able to produce cell injection pipette pullers in China, tests were run on test machines using Chinese-made material at different heating temperatures, pulling forces and pulling velocities based on variance analysis to study the variation of glass capillary pre-pull force within the permissible strength limits of 1 280 g～1 310 g, and the effect of heating temperature on length of pipette. Round pipettes to be used for micro-flow analysis were trial produced on test machines to study the effect of pull stroke and heating temperature on the inner diameter of pipette and diversify the performance of instruments. A design scheme is proposed for commercialization of pipette pullers.Keywords：microinjection;micropipette puller;glass micropipette;microchannel- 38
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- 5
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- 10
Published：2020-08-12 -
New pan-Cassegrain telescope system
Abstract：A new optical system with a fairly large field of view and excellent image quality can be designed by making both the surfaces of primary and secondary mirrors in the Cassegrain system spherical, adding two or more correcting lenses in front of the focal plane, and adding a 4th order term to one surface of the parallel plates as a hermetically sealed chamber. The aspheric surface of the plate with 4th order term is concave, and it can be made spherical by grinding it with hinge support around and equal loads applied, and after the equal loads being released, the surface springs back to form the desired aspherical surface with 4th order term. So, from the viewpoint of optical technology, this system has spheres and planes only. Four systems with relative apertures of F/3, F/5, F/8 and F/10 have been designed with the same effective diameter and field of view: φ=300 mm and 2 ω=1°, and the image quality is close to or reaches the diffraction limit.Keywords：parallel plate;pan-Cassegrain system;4th order term;equally-spaced load;hinge support- 37
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- 11
Published：2020-08-12 -
Optical design of high resolution echelle spectrograph
Abstract：The general theories behind echelle and its applications in astronomy are briefed, and the differences between echelle spectrograph and plane grating spectrograph are analyzed and compared. An optical design, which features the use of white pupil collimator system, R4 echelle with large blaze angle, and the fold and off-axial Schmidt camera without center obstruction, has been made for a high resolution echelle spectrograph (Large Sky Area Multi-Object Fiber Spectroscopic Telescope) under development, a more powerful tool for astrophysical research using high-resolution spectroscopy in China.Keywords：astronomical optics;spectrograph;echelle grating- 39
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- 9
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- 22
Published：2020-08-12 -
Adaptive alignment of fixed mirror by phase detection
Abstract：In order to keep the dynamic alignment Fourier transform spectrometer (FTS) between the moving mirror and the fixed mirror while the mirrors are moving and the temperature is changing, a phase detecting method is proposed for magnitude and tilt direction. The structure of dynamic alignment system and the basic principle of the phase detection are discussed. Fast steering mirror is adopted in the self-alignment system. The features and structure of the fast steering mirror are detailed. Alignment results show that dynamic alignment has obvious effects on performance.Keywords：phase detection;adaptive alignment;collimation;piezoelectric fast steering mirror- 35
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- 5
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- 9
Published：2020-08-12 -
Optical design for wedge-adjusted Talbot interferometer
Abstract：A wedge-adjusted Talbot interferometer, which includes one phase mask and two UV-reflected mirrors, has been developed to change the process of writing fiber Bragg grating. The interference fringe period formed by the ?1 order diffractive beams is changed by adjusting the reflected angles of two mirrors, and the fiber placed in the tuned interference fringe can then be fabricated to the fiber Bragg grating with various inscribed Bragg wavelengths. The changing ratio of the inscribed Bragg wavelengths and the displacement ratio of the diamond bridge of interfering fringe can be defined by selecting the wedges with different tilt angles.Keywords：Talbot interferometer;Fiber Bragg grating;Bragg wavelength;Displacement;UV reflector- 31
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Published：2020-08-12 -
Spectrophotometer for full-auto-biochemical analyzer
Abstract：Spectrophotometer is one of the key components in a full-automatic biochemical analyzer and it has its direct effect on the accuracy of the entire system. An ultraviolet-visual spectrophotometer has been developed for full-automatic biochemical analysis by using holographic aberration-reduced grating as spectroscope and photoelectron diode array as detector. Composite light coming from lamp-house is absorbed by sample solution first and then illuminated to the surface of the concave holographic aberration-reduced grating. The photoelectron diode array can receive 12 beams of light signal at the same time for fast measurement, and this is why it is referred to as back-dividing-light technologyKeywords：biochemical analyzer;spectrophotometer;concave holographic aberration-reduced grating;photoelectron diode array detector- 39
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- 5
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- 2
Published：2020-08-12 -
Development of light incidence system for laser resonance ionization mass spectroscopy
Abstract：An equation has been established for the transmission of optical parameters in a two-lens system using the Gaussian optical theory, and in the light of the structural features of NINT3000 laser resonance ionization mass spectrometer, an optical system and a laser path adjustment device were then designed using the above equation to achieve precise location and focusing of laser beam in the ion source cavity. The radius of the laser focal spot is 160 μm, and the adjusting precision being 10 μm. The system has now been installed in the laser resonance ionization mass spectrometer, and the homochromatic two-photon resonance ionizations of lutetium has been realized.Keywords：Gaussian laser beam;optical design;laser path adjustment device;resonance ionization- 35
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- 10
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- 1
Published：2020-08-12 -
Optimization of parameters structural design of lightweight reflector
Abstract：A parametric structure model has been established using FEA software ANSYS for an aspherical primary reflector with lightening sector holes. With some structural parameters having significant effect on mechanical properties of reflector, such as thickness of reflector, and location and size of sector hole, used as design variables, and feasible domains established in accordance with reflector machining and assembly processes for these design variables, an optimal design is done for the structure of a reflector using the zero-order optimization method provided in the Design Opt module of ANSYS. Mechanic analyses show that the optimized structure of the reflector is much lighter and stronger than the original design.Keywords：aspherical primary reflector;lightening;parameter optimization- 44
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- 16
Published：2020-08-12 -
Dynamic analysis for supporting structure of crossed-plate type
Abstract：Supporting structure of crossed-plate type is a typical secondary mirror supporting structure for a large-scale telescope, which determines the stability and veracity of LOS. A dynamic model has been established by selecting mode functions using the plate and shell theory and Rayleigh method. Numerical simulation and finite element analysis done with different structural parameters show that they both follow the same law and their results are generally in agreement, and therefore, this method can be used for calculating dynamic properties of similar structures.Keywords：supporting structure;shell and plate theory;numerical simulation;finite element analysis- 50
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- 6
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Published：2020-08-12 -
Prediction of micro drill break through thrust monitoring
Abstract：With 50 HSS twist drills of 0.4 mm in diameter used as samples on a CNC high speed precise drilling machine, limit thrust values of micro drill breaks were examined while No.45 carbon steel was drilled. It is concluded from parameter evaluation and statistics that the limit thrust values obey the logarithm normal distribution law. The way of monitoring the threshold of thrust was also developed using the reliability theory. Experimental on-line monitoring was run at different reliable levels. When the reliable level selected was 0.999 and the drill utilization ratio was the same as that of in ordinary drills, the drill break ratio of 10 drills decreased from 30% to 0.Keywords：micro drill;drilling thrust;on-line monitoring- 56
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- 9
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- 2
Published：2020-08-12 -
Method of calculating negative pressure-and-adsorption air cushion annular slide
Abstract：Negative pressure adsorption slide is a new air static pressure slide widely used for high precision, high speed and light load applications. A systematical mathematic model has been established in the light of the operating principle, and hydromechanics load-carrying capacity and gas film thickness of the slide. Some conclusions are drawn on four structural parameters, gas source pressures, load-carrying capacity and gas thickness, and finally, the slide's performance was verified through experiments. When gas thickness varies in 1～3 μm, the load-carrying capacity is stable ,maximal variation is about 10%, and the error between calculating stiffness and experimental stiffness is less than 12%. So, this slide can be used for mobile components or bearing components of precise appliances.Keywords：negative pressure and adsorption annular slide;load-carrying capacity;stiffness- 47
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- 7
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- 4
Published：2020-08-12 -
Automatic measurement of turbine rotor bend using laser scanning technology
Abstract：For the great importance of measuring turbine rotor bend for both inspection and repair of turbines, an automatic measurement system, which uses a rotating mirror for scanning, double slots for scanning speed calibration, an optoelectric detector for optoelectric change-over, and a microprocessor for processing, display and printing of data, is proposed for measuring turbine rotor bend using laser scanning technology. Experimental results show that the automatic measuring system is capable of doing remote non-contact measurements of turbine rotor bends with an accuracy of ±5 μm from 4 m away.Keywords：turbine rotor bend;laser scanning;non-contact measurement- 49
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- 8
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- 2
Published：2020-08-12 -
2D-Platform with cross diffraction grating as displacement measurement sensor
Abstract：The platform consists of coarse and fine stages, and the coarse stage is driven by a plane linear motor while the fine one by piezoelectric ceramics. The method of fast location control is proposed according to the driving range and precision of motors and piezoelectric ceramics. A circuit was designed to process grating signals to drive motor piezoelectric ceramics. The actual resolution of position measurement was computed from the practical precision of grating grid. Direct current amplification was chosen by analyzing a few high voltage circuits to drive these ceramics.Keywords：2D displacement platform;cross diffraction grating;four-pin detector;piezoelectric ceramics- 41
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- 9
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Published：2020-08-12 -
Design of real-time digital image processing system based on digital signal processor TMS320C6202
Abstract：Acquisition and real-time digital processing of images is realized by using high-performance digital signal processor TMS320C6202 as the core, large-scale programmable logical array CPLD for logic control, and field programmable grate array FPGA for preprocessing of images. The hardware composition of and the theory behind the real-time digital image processing system, and the application of the image processing algorithm are discussed in detail.Keywords：Digital signal processor;digital image processing;Automatic target recognition- 30
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Published：2020-08-12 -
Optical heterodyne scanning holography
Abstract：The theories behind both optical heterodyne scanning holography, a novel 3-D imaging technique, and circular grating optical scanning holography, a holographic technique based on optical heterodyne scanning holography, and its advantages over traditional optical heterodyne scanning holography, are discussed in detail, and some of optical heterodyne scanning holograph's potential applications, including 3-D remote sensing and medical imaging, are presented with typical examples given.Keywords：optical heterodyne scanning holography;Fresnel zone plate;circular grating optical scanning holography;3-D imaging- 32
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- 9
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- 3
Published：2020-08-12 -
Application of complex programmable logic device technology in graphic generator
Abstract：Field programmable gate array (FPGA) and complex programmable logic device (CPLD) are the mainstream of application specific integrated circuits (ASIC), and FPGA with million logic gate capacity has become a proven modern electronic research and development means. In the aerospace ground observation TV camera system with limited space available, CPLD design schemes are adopted to lower system power consumption, shorten R & D cycle and improve system reliability.Keywords：pattern generators;field programmable gate array;programmable logic device;integrated circuit- 57
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- 6
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- 1
Published：2020-08-12 -
Multi-target recognition with improved BP algorithm
Abstract：An improved BP algorithm has been proposed for realization of multi-target recognition. The principle followed is addition of an alternating momentum factor to the step function, i.e., the step length is doubled when the gradient directions of two consecutive iterations are the same, and the step length is halved when the gradient directions of two consecutive iterations are opposite. Due to the adaptive adjustment of step length in the iteration process, error function E approaches the minimum point in different directions on the super curved surface in accordance with the step length to realize the optimization of goal function. The recognition rates achieved using the improved BP algorithm with optimized goal function are better than 98%, and the improved BP algorithm's convergence speed is four-times fast than the convergence speed of traditional BP algorithm.Keywords：neural network;target recognition;BP algorithm- 44
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Published：2020-08-12 -
Image fusion based on neighborhood features of wavelet coefficients
Abstract：Selection of fusion-factors is essential for an image fusion process, and it is therefore studied by using wavelet transformation to do image fusion. In order to make better use of the excellent spatial-frequency characteristics of wavelet transformation, it is suggested to use the neighboring region features of wavelet coefficients, such as variance, to define the fusion factors. The performance of fusion algorithm should be evaluated by both the increase in information and the distortion degree of fused images, the entropy of fused image is used to express the amount of information contained in the image, and the crossing-entropy of fused image is used to express the distortion degree of fused image. Experimental results indicate that the algorithm proposed is excellent, and can be used to obtain very good fused medical images.Keywords：image fusion;wavelet-coefficient;fusion-factor;variance;medical image- 41
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Published：2020-08-12 -
Automatic optimization of image board parameters based on entropy
Abstract：In order to simplify computation and reduce system response time, an algorithm has been proposed for automatic optimization of image board parameters. Maximum entropy is obtained by establishing nine different states of image entropy from statistics at both ends of image histograms, dynamically adjusting the image board parameters in accordance with the states of image entropy, and then changing the brightness and contrast of images. Experimental results indicate that under the condition of single-frame time delay, this algorithm can be applied for adaptive optimization of image board parameters.Keywords：image board;entropy;Histograms;response time- 38
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Published：2020-08-12 -
Thinning of binary image based on stroke trend analysis
Abstract：In order to overcome the drawbacks of thinning based on the axle wire of the original image and eight-neighborhood, which causes some straight-lines with noise to become curves, and stroke distortion at the cross or crotch of strokes, an improved thinning algorithm based on stroke trend analysis is proposed for binary image by analyzing and improving Zhang thinning algorithm, and it can make a skeleton with strictly eight-connected structure available to keep a good symmetry, and control the deformation at the cross or crotch of strakes so that each image can be quickly skeletonized more perfectly.The algorithm proposed in this paper has been successfully applied to vehicle license identifying system.Keywords：image process;thinning;distortion;stroke trend analysis- 46
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Published：2020-08-12 -
Effect of input image size and elastic factor on 2D Morlet wavelet transform
Abstract：For a given size of 2D Morlet wavelet matched filter, both input image size and elastic factor have significant effect on experimental results. The study of the effect of elastic factor on wavelet transform through computer simulation shows that an excessively large elastic factor blurs the edge of transformed image, and the study of the effect of input image size on wavelet transform through computer simulation and optical means shows that experimental results are in agreement with results of computer simulation, and 2D Morlet wavelet transform can extract clear image edge features only when a suitable input image size is chosen to ensure that the frequency spectrum of input image is in agreement with the frequency spectrum of wavelet matched filter.Keywords：Morlet wavelet transform;Morlet wavelet matched filter;input image size;elastic factor- 49
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Published：2020-08-12 -
Application of Fuzzy controller with self-adjusting function for DC motor speed-regulating system
Abstract：A control algorithm, which combines the fuzzy controller with self-adjusting function with the binary function Lagrange interpolating algorithm and is used in a DC motor speed-regulating system is discussed. The type of self-adjusting function is an index function. According to different instances and requests. The parameters in self-adjusting function can be adjusted from the keyboard using the burst double Lagrange interpolating algorithm. This control algorithm has been proved to be reasonable and effective.Keywords：self-adjusting function;Fuzzy control;binary interpolating;DC speed-regulating- 47
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Published：2020-08-12
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