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Issue 8 ， 2008
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Research of Recognition Method for
Abstract：In order to realize the measurement of multiple targets position on the ground , a project of recognition for multiple targets track is established, and the recognition method in pixel coordinates for large area optical electronic measurement sets is researched . This method creates an evaluation function based on target motion, such as the direction, speed and acceleration, then decides the membership degree between point and track by the evaluation function, in this way the multiple targets track recognition is accomplished. During the curse of recognition, the author thinks the phenomenon of some points are lost in some frames, then replenishes the lose point by the track data with Kalman filter, thus the track continual isn’t destroyed. The correctness of the recognition method is affirmed by simulation and actual multiple targets track data. This method meets the requirement of multiple targets position measurement.Keywords：optical measurement;Multiple targets;Large area;Track recognition;Intersection measurement- 48
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Published：2020-08-12 -
Material removal efficiency in ion figuring process for optical components
Abstract：The removal efficiency and the relative removal efficiency between two different materials with three performance factors, normal removal rate, volume removal rate and sputtering yield are analyzed in the ion beam figuring process. With the Sigmund sputtering theory, build up are the relation models between these three factors and the processing parameters, such as ion energy, ion flux and ion incident angle. Experiments with samples of Zerodur, SiO2 and K4 are made to analyze these relations. The experimental results verify the theoretical models. The models and experimental results indicate that the removal rate increases with ion current linearly and is about proportional to the square root of the ion energy. The removal rate increases with incident angle and climbes the summit at about 60~80°; the relative removal efficiency is independent of ion flux; the energy effect of the relative removal efficiency can be ignored and the angle effect is rather obvious.Keywords：optics fabrication;ion beam figuring;ion sputtering;material removal efficiency- 45
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Published：2020-08-12 -
Numerical analysis of the Yb/Er co-doped double cladding fiber amplifier
Abstract：Numerical analysis of the Yb/Er co-doped double cladding fiber amplifier pumped at 980nm has been performed. The gain of the amplifier with different signal power, the distribution of population inversion, pump power and signal power along the axis direction of the fiber have been analyzed at stable-state. The calculated slope efficiency accords with the experimental result at a higher initial value of signal power.Keywords：fiber amplifier;Yb/Er co-doped double cladding fiber;Numerical analysis- 43
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Published：2020-08-12 -
Optical system design for MEMS based digital sun sensor
Abstract：Based on scalar diffraction theory, imaging model of digital sun sensor optical system is developed. The optical system has a structure of circular aperture. Simulation has been carried out on computer and parameter of optical system is designed on the results of these simulations. The ground experiment was carried out for this optical system by sun simulator. The results show that the optical system is designed well and is conform to the requirements of miniaturization and high accuracy of sun sensor.Keywords：digital sun sensor;optical system;diffraction- 53
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Published：2020-08-12 -
Study of Stray light Suppressing Measure by electrochemistry for 4J32 alloys
Abstract：In order to realize stray light suppressing for 4J32 alloy in Optical System, stray light suppressing coatings were prepared on 4J32 alloy from a conventional anoditation-plating bath containing Ce and duable salt additive. The bath formula and rational process parameters were investigated making use of orthogonal test. By testing the influences such as concentration of K2Cr2O7, MnSO4, (NH4)2SO4 , in electrolyte solution , galvanic voltage , operating temperature , anodizing time, etc. on the anodizing films of TC4 alloys , the optimal process condition were gained as follows: 20g/L K2Cr2O7,20g/L MnSO4, 20g/L (NH4)2SO4, 15g/L Ce and duable salt additive temperature of 25℃、last time of 20min、voltage of 30V. A black stray light suppressing film were gained by the process. The results of reflection testing, thick testing and shock testing showed that 4J32 stray light suppressing coating has low-reflecting ratio( reflecting ratio 1.5%±0.5%), few dimension change (<0.8μm) and good adhesion to substrate. The film are suitable to suppress the stray light in optic system.Keywords：4J32 alloy;electrochemistry method;stray light- 60
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Published：2020-08-12 -
Research on a Fiber-Typed Variable Optical Attenuator
Abstract：The attenuation detectable device of a Variable Optical Attenuator (VOA) is designed. The basic enactments of the two tapered fiber parameters are: The fiber core radius a =20 , the lateral displacement u =158 , the longitudinal superposed length L =100 , the tapered angle , the fiber core refractive rate =1.47, and the envelope refractive rate =1.46. Then, based on coupling theory, through changing one parameter above, the relations between the attenuation and the corresponding parameter are analyzed, and the wavelength minim-loss characteristic which can guarantee the reliability and singleness of the gas concentration when the gas concentration measurement and identity are done is discussed.Keywords：VOA;tapered fiber;coupling;wavelength minim-loss;attenuation- 33
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Published：2020-08-12 -
Analyze and Optimal Design of Illuminator for Leadless Tin Solder Joint Inspection
Abstract：This paper presents an illuminator for Leadless tin solder joint inspection. Firstly, the structure of the designed illuminator is introduced. Secondly, the radiance model of the illuminator and the irradiance model of the solder joint are developed. Thirdly, the dimensions of the illuminator are optimized based on the irradiance model. Finally, the simulation and experimental results verify the validity of the design.Keywords：AOI;LED;Illuminator;machine vision;Solder Joint Inspection- 30
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Published：2020-08-12 -
Null Corrector for Φ1.2m F/1.5 Paraboloidal Mirror
Abstract：Null corrector forΦ1200 F/1.5 paraboloidal mirror must compensate 0.087mm surface departure from the best fitting sphere, and realize the surface error less than 0.033λ（RMS）. The design, error analysis, manufacturing, certification and final application of the corrector are introduced in detail. The certification by computer-generated hologram (CGH) in advance shows that the shape and conic errors produced by corrector are 0.012λ（RMS）and 0.0064%, and the final null testing results, surface and conic error, of primary mirror are 0.027λ（RMS）and 0.0306%,all these are consistent with the tolerance analysis. The results indicate the design ，tolerance analysis and quality of corrector are rational and reliable, and this has laid solid foundation for the null test of larger fast primary mirror.Keywords：optical fabrication;Asherical testing;Null test;Corrector design;Corrector certification- 47
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Published：2020-08-12 -
Study on the Method of Emulate Design of the Saddle -shaped Parallel Tracking Platform
Abstract：Abstract:Using the saddle-shaped parallel tracking platform, the emulate design method combining the Matlab emulate code with the ADAMS emulate analyses is given in this paper so as to improve the emulate design velocity of the parallel device. Compiling the Matlab emulate code to optimize the saddle-shaped parallel tracking platform and using the optimum design size to realize the 3D reconstruction. The 3D model is analyzed in the ADAMS environment and the saddle-shaped parallel tracking platform experiment sample is manufactured by using the emulate result. The correctness of the emulate results are proved by compiling the data monitor module code to monitor the velocity of the experiment sample drive poles and comparing the monitor results and the emulate results. Study shows that, this emulate design method can avoid the problem of repeated 3D reconstruction and the emulate design periodicity is half of the current method periodicity.Keywords：Saddle-shaped;Parallel tracking platform;Emulate design;Experimental verification- 49
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Published：2020-08-12 -
Fabrication of a flexible three-dimensional neural microelectrode array
Abstract：The interface between neurons and electrodes is one of the key issues in implantable microdevices and bioelectronics. However, the traditional sandwich-type planar mciroelectrtode arrays are not well suited for effectively stimulating or recording due to no tight contact between the neuron and the planar electrode. To overcome this problem, we proposed a method to fabricate the flexible 3D protruding microelectrode arrays (MEAs) for neural applications. A photosensitive polyimide (Durimide 7510) was used as substrate materials, and the MEAs with the structure of pyramide-shaped microelectrode was fabricated by the procedures of wet etching, photolithography, lift-off, electrochemical etch release and so on. The pyramid-shaped electrode configuration allows electrode sites to get closer to target neurons. A comparison between the planar and 3D protruding electrode configuration was performed by simulaiton and resistance test. The results show that a better stimulation can be obtained with the 3D electrode devices.Keywords：artificial vision;Three-dimensional flexible electrode;Microelctrode array;Surface area of electrodes- 36
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Published：2020-08-12 -
Study and improvement on Ablation System in Mass Spectrograph
Abstract：The MS melt-like system includs Two types, Laser fusion-like and Melting-like graphite furnace. Laser Ablation System (LAS) is usually commercial module, whose function operation and process control are relatively independent. When used in MS, the LAS is restricted in centralized controll and coordinated operation. To improve the ablation precision, efficiency and automation of the LAS in MS, this subject regarded the Inert Gas Isotope-MS as experimental subject, and made a study on intelligent Laser Ablation System in MS. A two-dimensional sample worktable is redesigned, the Automation of Graphite Furnace Injection System is also Designed.A series of control subroutine are designed, and the vision system is calibrated. The realization of Intelligent Laser Ablation System provide a base for the current intelligent development of MS.Keywords：Intelligent;laser ablation system;mass spectrograph (MS);calibration- 36
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Published：2020-08-12 -
An approach for determining the mean line in surface metrology applying B-Spline filter
Abstract：According to Z-transform representations of discrete B-Spline functions, the fitting and decomposing of the signal in B-Spline space can be implemented by FIR filters and IIR filters. Based on that and variational calculus, the B-Spline filter constructed to determine the mean line in surface roughness measurement comes into being. The difference equations for B-Spline filter is deduced by the technique of zero phase shift filtering. The experiment in the surface profile of a workpiece validate this method. The B-Spline filter also bears the characteristic of zero phase shift and has more computing efficiency than other methods.Keywords：B-Spline filter;Signal fitting;Mean line;surface roughness- 50
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Published：2020-08-12 -
Experimental study of borosilicate glass film bending with CO2 CW-laser
Abstract：Experiment of borosilicate glass film bent by CO2 CW-laser was presented．The effects of process parameters (laser power (P), scanning velocity (V), number of scanning (n)) and work piece geometry (specimen width(d))on the bending angle are investigated, then the experimental phenomenon was analyzed．A extent diagram of the value of P，V was generalized for the bending progress，meanwhile，several groups of processing parameters were obtained．Experimental result indicates that the borosilicate glass film could be bent an angle up to 24°using CO2 CW-laser．Keywords：laser bending;borosilicate glass;thermal stress;bending angle- 42
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Published：2020-08-12 -
Evaluation Method for Spatial Straightness Errors Based on Multi-target Optimization
Abstract：Based on the conditions of minimum zone method, a non-linear programming model is build for spatial straightness error evaluation. This non-linear model is further proved, in essence, to be a multi-target optimization problem, and can be transformed into a single-target optimization problem. A unified and efficient successive quadratic programming method ( SQP algorithm) is proposed to solve these model. As the non-linear programming model is convex and SQP algorithm can retain such non-linear information, the method has very loose requirements on initial parameters. Also, this method is very stable, reliable and highly efficient in optimization. Several experiments of Spatial straightness error evaluation fit the requirements for convex programming’s global optimization very well which has proved these conclusion.- 24
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Published：2020-08-12 -
An underground pipeline detecting system based on PSD
Abstract：An underground pipeline detecting system is required because trenchless technology is common. In this paper, we designed a device to detect the orientation of the pipes underground which composed PSD (Position Sensitive Device) and other components by combining the data at different measuring site. Based on the analyzing result of experiment, an instance supplied by a trenchless company shows the relative error of the detecting method can meet the requirement of detecting in practical construction.Keywords：PSD;trenchless;underground pipeline;interposition- 41
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Published：2020-08-12 -
Study on the Adaptive Capacity of Stewart Platform
Abstract：Abstract: In order to process the ground test for aerial cameras of different types, a stewart platform was needed that is with load adaptive capacity. Considering the range of cameras’ weight and the electrical-mechanical structure of the stewart platform that has been designed, the relationship between the load(aerial cameras) and the potentiometer(position feedback devices) signal amplitude was studied. A method to measure the moment of inertia of the load automatically was advanced using numerical calculation method. The method can be achieved easily, and it does not need to add any device for most digital control systems that have existed. Simulation experiments showed that the measuring error was 0.03967.Keywords：key words:;adaptive capacity;moment of inertia;measure- 23
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Published：2020-08-12 -
Study on the Phase Transformations of the Ground Monocrystalline Silicon Wafers Surfaces
Abstract：In order to understand the material removal mechanism during wafer rotation grinding, this study investigates the phase transformations on the ground silicon wafer surface with the aid of Raman microspectroscopy. The results show that，the amorphous silicon (-Si ), Si-III phase, Si-IV phase and Si-XII phase existing on the semi-fine and fine ground wafer surface indicate that the Si-I phase is transformed to ductile metal phase (Si-II phase) during grinding. The Si-II phase is ductile and easily removed by ductile mode. There is no obvious polycrystalline silicon on the rough ground wafer surface. Only very small amount -Si is observed. The material was removed by brittle mode. From rough grinding to fine grinding, the material removal mode changes from micro-fracture mode to ductile mode gradually. During the transition from rough grinding to semi-fine grinding, with the increasing of the phase transformation degree, the ductile mode removal degree increases. During the transition from semi-fine grinding to fine grinding, the ductile mode removal degree increases as the phase transformation degree decreases.Keywords：Silicon wafers;grinding;Phase transformations- 44
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Published：2020-08-12 -
Research of Single Axis Attitude Control and Energy Storage System with Two Flywheels
Abstract：A single axis double flywheel integrated power and attitude control system (IPACS), including its working principle and configuration, are given to simulate the charge, discharge and attitude control process during the full sun and the eclipse. According to simulation analysis, it proves to be feasible that single axis double flywheel integrated power and attitude control system, and the impact of the system parameter on the control precision is discussed, then the parameter optimization approach is offered. The experiment equipment of single axis attitude control and energy storage system is founded and the experiments on 20000 rpm speed show that the system can be used to store and release energy while adjusting the attitude of the platform, as well as of the satellite. The angle of the platform can be controlled to stabilize within 1.5 º and 1.2', respectively. At one time, the bus DC voltage is 24V and the fluctuating is less than 1.8%. After eliminating unbalance affection, such as the difference from motors, the scheme using flywheels to perform the energy storage and attitude control in the satellite is efficiency.Keywords：satellite attitude control;integrated energy storage and attitude control system;double flywheel in single axis;Computer simulation;experiment study- 48
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Published：2020-08-12 -
SVM Generalization Error Estimation for Facial Features Selection
Abstract：According to statistical learning theory, feature selection is realizable by valid heuristic search stage, which minimizes an estimated generalization error or some other related performance measure of SVM. In this paper, we introduce a facial features selection method. The optimal features subset is selected by minimizing VC leave-one-out (LOO) error or span error estimate of support vectors, which are regarded as the feature selection criterion of wrapper approach, through recursive feature elimination (REF). Face recognition is essentially a pattern recognition problem with typical small-sample size in sparse hyper-high dimensional space. The basic or most important part is how to obtain the significant features for classification. Theoretically, combing feature selection with classification model design outperforms traditional feature extraction or feature selection methods. Therefore, we propose a novel framework of the facial features selection based on filter (WT+KPCA) and wrapper (minimizing generalization error estimation) approaches. Experimental results on UMIST face database indicates that the proposed feature selection framework is time efficiency and has a significant improvement on the classification accuracy.Keywords：SVM generalization error;facial features selection;Filter;Wrapper;RFE- 17
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Published：2020-08-12 -
Illumination compensation based on multi-level wavelet decomposition for face recognition
Abstract：The appearance of a face will vary dramatically when the illumination changes, which makes face recognition even more challenging. In this paper, an illumination compensation method by means of multi-level wavelet decomposition and spline interpolation is proposed to reduce the effects of illumination variations on face recognition. A lighting change in an image can be modeled as an additive noise in addition to a multiplicative one. The additive noise, called background, can be estimated and taken out by multi-level wavelet decomposition followed by spline interpolation; the multiplicative one, called gain, can be done as the similar way in the logarithm domain. Experimental results on Yale B face database show that the proposed method achieves 2~11% recognition rate upper than the others. It can efficiently composite the facial images under varying illumination conditions, as well as improve the recognition rate and robustness of face recognition.Keywords：face recognition;Illumination composition;Multi-level wavelet decomposition;Slpine interpolation- 24
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Published：2020-08-12 -
Random Sampling Subspaces Locality Preserving Projections for Face Recognition
Abstract：In pattern recognition, combining multiple discrepant and complementary classifiers can improve the accuracy and stability of identification system. Bagging, boosting and random subspace methods are commonly used to combine multiple weak learners. A random sampling subspaces locality preserving projections (RSSLPP) method is proposed to improve the recognition performance of a single locality preserving projections (LPP) in this paper. At the training stage, several random sampling principle components subspaces are generated by random sampling the principle components subspace of training set. Then, multiple discrepant and complementary locality preserving projections subspaces are generated by applying locality preserving projections method to the projected samples of training set on the random sampling principle components subspaces. At the recognition stage, test sample is successively projected into each random sampling principle components subspaces and the corresponding LPP subspaces. On each LPP subspaces, the nearest neighbor classifier is used for classification. Finally, majority voting criterion is used to fuse the recognition results of each LPP subspaces. Experiments on FERET subset illustrate that random sampling subspaces locality preserving projections method effectively combines the complementary information of each LPP subspaces and improves face recognition accuracy.Keywords：Random Sampling Subspaces LPP;LPP;Subspaces;face recognition- 28
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Published：2020-08-12 -
Facial Expression Recognition Based on Supervised Kernel Local Linear Embedding
Abstract：Manifold learning method can discover intrinsic low-dimensional submanifold embedded in the high-dimensional image space, it attracts more and more attention in the research area of biometrics and cognitive science. However, manifold learning is an unsupervised learning method, the discriminative ability of the low-dimensional feature obtained by the algorithm is often lower than those obtained by the conventional dimensionality reduction methods. Furthermore, manifold learning methods don’t have direct mapping for new example, so it’s difficult to acquire the low dimensional features of new example. To address the two problems, this paper introduces a novel supervised kernel local linear embedding (SKLLE) method for facial expression recognition, it maps face images to high dimensional kernel space through nonlinear kernel mapping, then fuses prior class-label information and nonlinear facial expression submanifold of real face images to extract discriminative features for expression classification. SKLLE can not only gains a perfect approximation of facial expression manifold, but also enhances local within-class relations. It also does well on the new samples. Experimental results show that the proposed method can improve face expression classification performance effectively.Keywords：manifold learning;kernel trick;local linear embedding (LLE);supervised learning;facial expression recognition.- 19
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Published：2020-08-12 -
Image Encryption Algorithm Applied to Rectangular Image Based on New Two-dimensional Map
Abstract：Nowadays image encryption methods are mostly confined to a square image encryption, it proposed a new encryption algorithm which can be applied to both square and rectangular image encryption. Apply the new map that based on image segmentation to the location scrambling, and carry out image gray scrambling by using spread function that contain chaos map, so as to get an image encryption algorithm which combine position and gray scrambling. The results of Simulation show that this algorithm can achieve good image encryption of any size, and has a large key space, key sensitivity and it also has many other advantages such as withstand statistical and known expressly attack.Keywords：image encryption;scrambling;diffusion;chaotic map- 22
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Published：2020-08-12 -
Optical Implementation Method of Mallat Algorithm
Abstract：For the existing optical wavelet transform were implemented all based on continuous wavelet transform, rather than discrete wavelet transform，its applicability was restricted . To solve this problem, the principle of the optical implementation method of discrete wavelet transform algorithm (Mallat algorithm) utilizing optical 4f system was analyzed, and its optical implementation method was proposed. For SLM(Spatial Light Modulator) can only implement nonnegative real function and CCD can only record light intensity, one design method of optical wavelet filters which were applied to optical 4f system was given. With this kind of optical wavelet filter, the wavelet decomposition in Mallat algorithm was implemented utilizing optical 4f system, and the wavelet reconstruction in Mallat algorithm was implemented by use of numerical computation. Experimental results verify the methods.Keywords：information optics;Mallat Algorithm;Optical wavelet transform;Optical 4f system- 62
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Published：2020-08-12 -
The Research of Cell injection Device Based on TMS320DM642 and S3C2410
Abstract：Cell injection device are generally adopted manual operate machine at present and have the problem of low efficiency and low velocity, consequently, The experiment device that use DSP chip TMS320DM642 to accomplish image sample and process, And store the result to special RAM. Use ARM9 chip S3C2410 to accomplish man-machine conversation 、macro-micro dual drive control is present. Use the HPI interface of TI to transfer data between DSP and ARM. The experiment results show that the pixel level positioning precision can obtained, Increased the velocity of image process and motion precision of system, resolve the problem of heavy workload、inaccurate precision and low efficiency when manual operate cell injection device at present.Keywords：Cell injection device;macro-micro dual drive;vision servo control;HPI interface- 50
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Published：2020-08-12 -
Research on automatic focusing techniques based on illumination optimum
Abstract：This paper discusses the opinion that illuminating intensity will seriously affect the effectiveness of automatic focusing techniques in the microscopic vision research field. An automatic lighting control system is developed to provide experimental conditions in illumination research. Firstly, a tool of Fast Fourier Transform (FFT) is used to analyze spectrum of a sequence defocused images and a sequence images under different lighting intensity, proving that lighting intensity conditions impact significantly on the high frequency energy of images. Then, a function that can evaluate high-frequency energy of images is proposed. Finally, some auto-focusing experiments are executed. Experimental results show that lighting intensity has a great impact on focusing curves, and higher accuracy can be achieved after illumination optimization than usual method.Keywords：microscopic vision;automatic focusing;illumination;optimum- 49
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Published：2020-08-12 -
Research on Surface Irregularity Influence of On-axis TMA Mirror
Abstract：On-axis TMA (Three Mirror Anastigmatic) is a popular form used in lightweight high resolution space-borne camera. Mirrors of on-axis TMA are often aspherical, whose surface accuracy are influenced by environment and manufacturing. Environment endurance is decided by structure design, and manufacturing is connected to time and cost. So, every factor should be synthesized and analyzed to ensure the designed resolution of optical system, and do not lead to any waste. Take some actual on-axis TMA system with a Φ600mm primary mirror for example, surface irregularity influence to Gaussian focus wave-front error is analyzed, and mathematic expression of the influence is acquired.. Circle field fixed Zernike polynomial is used as a opt-mechanic interface to analyze the environment influence on primary mirror and system performance degeneration. Taking the result as reference, supporting structure of primary mirror is improved. Based on the Marechal criterion and environment endurance, the manufacturing accuracy of primary mirror is deduced, which should precede λ/36.5.Keywords：on-axis TMA;Zernike polynomial;surface accuracy;wave-front error- 40
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Published：2020-08-12 -
The relationship between swath width of space borne optical sensor and orbital elements
Abstract：The swath of space borne optical sensor is an important index in many space missions. For satisfying the swath requirement of optical payload, besides a reasonable design of optical system, a suitable design of orbital elements is also needed. Sun-synchronous orbit (SS-O) is one of the most frequently used orbits for earth observation missions, and orbital altitude is a challenge attention index in SS-O design. The key point of satisfying mission requirement is designing a suitable SS-O. The relationship between swath width and orbital elements (especially the orbital altitude) is discussed in this paper; a method of SS-O design satisfying the swath width requirements of space borne optical sensor is also given. Firstly, this paper discusses the theory of non-spherical earth perturbations and the definition of SS-O. Afterwards, the relationship among nodal period, fundamental interval and orbital altitude will be educed, with deriving the definition of fictitious node. Finally, we get the restriction condition of orbit altitude satisfying swath width requirement, based on the discussion above. The definition of fictitious node, which is very helpful to comprehend the theory on SS-O, is first put forward. Furthermore, the mathematical relationship between SS-O nodal period and orbital semimajor axis is deduce, which is available for SS-O design.Keywords：sun-synchronous orbit;non-spherical earth perturbations;fictitious node;nodal period;fundamental interval- 37
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Published：2020-08-12 -
Research of Switch Arithmetic for quick small satellite Attitude Maneuver
Abstract：Much more functions and higher quick maneuver were required with the development of aerospace technology. Thus the development of large currently, quick small satellites with high precision and stabilization has been one of the key trends. And from the comprehensive survey of satellite development in foreign countries, the Single Gimbal Control Moment Gyroscope (SGCMG) is a commonly used controller in the control system of large satellites. The SGCMG is excelled from traditional flywheel systems from the performance, but existed singularity problems. Especially used SGCMG in the small satellite, the singularity problems is all the more prominence. Therefore, the research on SGCMG is concentrate don’t he steering law study for avoiding singularity. This paper, aimed at crucial problems in the application of SGCMG to quick small satellites, is studied to afford basis for the application of moment gyroscope in aerospace engineering. Used model of small satellites with rigid bodies, Educed switch control for with reason adjust toques of small satellite with SGCMG, and avoided saturation singularity. Used pseudo-inverse steer lay with zero-motion control SGCMGs. As a result of the simulation, small satellite has been all right capability of large angle maneuver, rotated 45° at 14s, average rate achieve 3.2°/s. Proved out this switch Arithmetic has meet need of quick small satellite.Keywords：quick small satellite;attitude maneuver;switch Arithmetic;SGCMG- 87
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Published：2020-08-12 -
Design of New Type Spaceborne Lightweighted Primary Mirror Support
Abstract：Abstract：With the increase of the spaceborne telescope primary mirror size，the gross weight of the whole optical system is increasing leaped. It’s in contradiction to the desire of the optical system development trends which is smaller and Lighter. In order to satisfied the development desire, the article started with the lightweighted design of the primary mirror sub-assembly structure.The influence of the material thermal math, lightweight pattern and optimal support structures was considering during the mechanical/thermal design process. In the article a higher resolution Cassegrain optical payload which primary mirror isφ650mm was designed and it’s specially support system made reflectors of the space remote sensor keep both high rigidity of structure and fine stability of thermal dimension better. Considering the telescope manufacture and work station, a reasonable and optimal structure of the primary mirror sub-assembly is taken finally, and its PV is less thanλ/10 which is satisfied to the high resolution satellite primary design requirements.Keywords：lightweight;Primary mirror;Support- 68
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Published：2020-08-12 -
Research on momentum management
Abstract：In recent years, with the continuous development of space technology and space missions, the fast slew maneuvers of small satellites are required. Now research and produce small satellites which can slew fast is becoming the emphases in many countries. Adopt control moment gyro (SGCMG) which has a high torque output and control precision can upgrade the slew maneuvers of small satellites. Successfully developed SGCMGs to small satellites in outer space exploration will have an important national defense and military significance in China. This paper expatiated the basic theory of the SGCMG, designed SGCMG prototype, and had completed the SGCMG hardware - in - loop simulation experiment. The result indicates that the SGCMG which used to control small satellite attitude ,can complete fast slew maneuvers in little time. This paper is for SGCMG’s small satellite applications in a few key issues and conducting research for the SGCMG in China on small satellites to provide the basis for practical engineering applications.Keywords：SGCMG;small satellites;fast slew maneuvers;attitude control- 29
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Published：2020-08-12 -
Research on the satellite attitude control simulation test bed based on Variable-Speed CMGs
Abstract：The paper describes the details of a new kind of 3-axis air bearing test bed based on variable-speed control moment gyro for satellite attitude determination and control system simulation. The base of the test bed is a 3-axis air bearing platform newly developed by CIOMP. The main actuator of the system is a cluster of four variable speed control moment gyros constructed in pyramid mounting arrangement. The system also includes six gas thrusters to assist VSCMGs avoid singularity. The attitude determination system is also introduced which consists of three fiber optical gyros, a horizon sensor and a magnetometer. The details of main parameters of all parts and analysis of them are given to illustrate the platform can be used in the simulation and validation of many algorithms for modern agile small satellite. It can be used for reference by other facilities in this research field.Keywords：attitude control;3-axis air-bearing test bed;VSCMG- 37
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Published：2020-08-12 -
Design of high precision Small Satellite Constellation Laser Communication Simulation Platform
Abstract：One new high precision small satellite constellation laser communication simulation system is introduced, based on the demand of small satellite constellation laser communication between satellites. The system consists of two simulative satellites and a control center. The simulative satellite based on high precision triaxial flotation Turntable is comprised of satellite computer and diversified attitude sense organs and attitude executers on satellite. High precision triaxial flotation Turntable can afford the working environment for satellite, the satellite computer and the attitude sense organs and attitude executers manage to make the triaxial flotation Turntable get high pointing accuracy. The simulation system can work in many modes, including Master-Slave mode for double satellites, cooperative mode for double satellites, Master-Slave mode for three satellites, cooperative mode for three satellites and single satellite failure mode. The paper established coordinate for the system and bring forward mathematic model. At the end, the simulation is given, and the simulation can satisfy the demand of small satellite constellation laser communication.- 38
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Published：2020-08-12 -
The Design and optimize analysis of a Lightweight Outer Baffle for a Space Camera
Abstract：In this paper，the structure of the outer baffle that designed for a space camera are investigated. In order to achieve the minimum weight, the finite element optimization method is presented for the design of the outer baffle. According to the dimension of baffle and the inequalities relating to baffle’s mode and camera parameters given in this work, the thickness of the outer baffle and optalstop can be determined. The optimization result reduces the weight by 38.9% but the modes of the baffle change a little and the impulsion in the progress of the launch reduced simultaneously. Then the static analysis and dynamical analysis are provided by means of finite element methods , the results satisfy the desires of design which can be used in the work.Keywords：Outer baffle;Optimum design of structures;finite element analysis- 49
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Published：2020-08-12
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