Observability of optical monitoring data based on single space-based satellite is poor when the orbit is improved, iteration cannot be converged and even normal equation would be ill-conditioned, which would cause failure of cataloging and orbit determination of a large number of space targets. Features and difficulties of application of single-satellite optical monitoring to determine the orbit of space target were analyzed. Then the rank deficiency of orbit determination based on space-based monitoring and the observability of orbit determination of single-satellite optical monitoring were studied. On the basis of priori orbit information, a virtual ranging model was established. An orbit improvement method that combined virtual ranging and space-based angle measurement data was put forward, which improves the observability of optical monitoring data orbit determination system based on single space-based satellite. The verification was implemented on the basis of measured data of more than 400 targets monitored in 40 days in 2015 by the first space-based monitoring test satellite of China. After virtual ranging was added, success rate of orbit determination is increased from less than 10% to 90% above and the precision of orbit determination is improved as well.

To correct and improve calibration and measurement precision of optical element performance at 5—140 nm waveband covered by metrology beamline, a scheme for higher-order harmonic suppression was designed based on spectral radiation standard of State Synchrotron Radiation Laboratory and distribution of higher-order harmonic of the metrology beamline. The distribution of the higher-order harmonic of metrology beamline at 5—140 waveband was studied by use of 3 500, 840 1/mm gold-film self-support transmission gratings and a photodiode detector. Thus a method to suppress higher-order harmonics at different wavebands with Si, Al, Al/Mg/Al filter and LiF window and MgF2 window was put forward. Experimental result shows that the content of higher harmonic without filter is extremely low in 5—15 nm waveband, the proportion of higher-order harmonic with quantum efficiency corrected by detector can be suppressed below 1.8% in 5—40 nm waveband when proper filter is added at the corresponding waveband; LiF window and MgF2 window can basically make higher-order harmonic proportion zero in 105—140 nm and 115—140 nm wavebands. The scheme for suppression of harmonic waves with filters at whole waveband is effective.

In order to eliminate the surface microdefect after the direct polishing of RB-SiC substrate, reduce the surface roughness and increase the surface quality, Si was selected as the modified material based on the features of large aperture SiC, where a 2 m-level RB-SiC substrate was modificated by using the magnetron sputtering technology. The silicon film was deposited by a developed Φ3.2 m magnetron sputtering coating machine, and the SiC substrate was polished and modificated based on the computer control optical molding method. The result indicates that the thickness of modified level reaches 15 μm; the thickness uniformity of the film level is better than ±2.5% within the diameter of 2.04 m; the surface roughness decreases from 5.64 nm (RMS) to 0.78 nm. Therefore a the magnetron sputtering technology can be used in the surface modification of the large aperture RB-SiC, and the performance of the modificated RB-SiC substrate can meet the requirements of high-quality optical systems.

In view of the importance of surface shape fitting precision of free-form surface model in researches such as free-form surface representation and selection of initiating structure of surface shape, the influence of different sampling point distribution patterns on surface shape fitting precision of the Gaussian Radial Basis Function Based on Slope( Gaussian RBF-BS) model was investigated. An off-axis quadric surface and an bumpy paraboloid were fitted with different sampling point distributions which were uniformly random points and edged-clustered points. The results show that the uniformly random grid is better for surface shape fitting due to the high precision. The influence of sampling point quantity on fitting precision remains constant when certain fitting precision is reached. The off-axis Three Mirror Anastigmat(TMA) system was optimized experimentally by using initial surface shapes generated with different sampling methods. The results show that, by using initial surface shape generated from uniformly random sampling method for the system optimization, the average Modulation Transfer Function (MTF) of whole field of view is more than 0.72, which is much higher than that by using surface shape generated by edge cluster sampling points. Thus the theoretical research results were verified.

The factors and its mechanism which influence 4f imaging systemic resolution in practice were studied to guide the design and adjustment of the system. Firstly, the influence of the aberration caused by adjustment error on the system optical transfer function (MTF) in theory, whereby the mathematic model for describing the relationship of them was established. Based on the model, the adjustment error of 4f optical imaging system of 1 μm resolution was derived, and the influence of lens eccentricity, incline and displacement on the MTF was simulated, thus the variations of the resolution with the errors were achieved. The result indicates that within the incline of 15″, the eccentricity error is 0.02 mm and the displacement is within 0.01 mm. The adjustment error results in the decline of the resolution. Although the resolution increases while the incline within a minimum scope, the total trend will not change. The relationship figure of adjustment error and resolution can provide the reference for the error estimation of high-resolution 4f imaging system.

In order to extract laser stripe centers accurately and quickly and provide more suitable extraction results for binocular vision measurement of feature dimension, a laser stripe center extraction method with equivalent matching point was proposed. The gray centroid method was employed to extract central points of laser stripe, to calculate gray-gradient directions and to determine boundaries of laser stripe. Then coarse extraction results of laser stripe in the left and right images were used to determine reference laser stripe, with which the interpolation of corresponding laser stripe in another image was conducted. The laser stripes were extracted again based on gray-gradient directions and interpolation results and then sub pixel center coordinate with equivalent matching point was gained. Afterwards, the central point extraction results of the laser stripe were used to reconstruct surface feature information of ceramic plate, metal plate and forge piece on processing site. Experimental results show that, matching ratio for extraction of laser stripe centers of ceramic plate and metal plate with this method reaches 99.887% and 98.276% respectively as well as relative error for reconstruction of width is 0.638% and 0.488% respectively. Center extraction results of laser stripe can rebuild surface feature information of forge piece effectively and can meet measurement accuracy, speed and robustness requirement on industrial site.

An improved exact measuring angle algorithm is proposed for parameter calibration of area array cameras. Based on a given estimated principal point of camera, the algorithm calculated deviation between the estimated and actual principal points and focal distance of the camera by using the corresponding relationship between intersection angle of two beams of parallel lights and image point of projection on the camera. The influence of image feature extraction error on intersection angle measurement accuracy of parallel lights was analyzed and an optimal estimation based on the minimum intersection angle error of parallel lights was employed so as to promote the calibration accuracy of internal parameter of the camera. Simulation experiment was conducted to analyze the influence of image feature extraction accuracy and intersection angle measurement accuracy of parallel lights on camera parameter calibration precision. The results show that the calibration accuracies of principal point and focal distance can reach 0.56 pixel and 0.06 mm respectively when image characteristics extraction accuracy is 0.1 pixel and two-dimensional rotary table accuracy is 0.5″. An two-dimensional rotary table with accuracy reaching 0.5″ is used for parameter calibration of the camera. In comparison of intersection angle error of parallel light calculated based on image point and calibration results with the calibration result, the error of the improved algorithm is 68.6% of the classic exact measuring angle method. This proves that the proposed algorithm has a better accuracy in parameter calibration of area array camera.

A portable bio-aerosol short-rang lidar-measuring system which meets laser irradiation eye-safe requirement was established to realize real-time warning and monitoring of aerosol of biological warfare agent in human activity areas. Taking a 405 nm semiconductor laser with high-frequency modulation as the excitation light source and a 200 mm-caliber Cassegrain telescope system as the signal light collection system, the portable bio-aerosol laser radar short-range lidar-measuring system based on pseudo-random modulation was mounted. The system was equipped with 4 synchronizing detection channels: parallel polarization scattering and vertical polarization scattering light detection, 450 nm and 530 nm waveband fluorescence detections. Bacillus subtilis, staphylococcus aureus and yeast was taken as examples in the preliminary test of the laser radar system. The out-field experiment shows that the spatial resolution of the bio-aerosol lidar-measuring system is 1.5 m and detection distance of fluorescence channel is 100 m; the false alarm rate of back substitution for variety recognition of three bio-aerosols is 9%, 11.5% and 14.5% and crossing false alarm rate is 113%. The laser energy of the lidar system is lower than the requirement of laser irradiation eye-safe standard and it realizes identification of bio-aerosols basically.

To improve the stray light testing ability and calibration accuracy of the stray light equipment used in test of the Point Source Transmittance (PST), a calibration lens was proposed to calibrate the testing range and testing accuracy of the equipment in a large off-axial angle. By using a simple physical model, the calibration lens was designed in a laboratory. The physical parameters of the calibration lens were measured, then these parameters were taken into the TracePro to calculate the PSTs in different off-axial angles. Finally, the calculated result and the tested result of PSTs were compared, and the test accuracy of the equipment were obtained. The experimental results indicate that the difference between calculate results and testing results of the calibration lens is better than lg/0.5, meeting the need of testing accuracy calibration of the stray light equipment in testing PSTs and providing a reliable reference for the absolute measurement of PSTs. This technology solves the problem in testing accuracy calibration of PST measuring systems.

Based on ultrasonic vibration added in radial direction of saw-cutting ultra-thin abrasive cutting wheel, two kind of optical glasses with different physical properties were fabricated to explore the influence of radial ultrasonic vibration on saw-cutting process. The sawing force and sawing energy were deduced theoretically, and the cutting paths of single abrasive in conventional and ultrasonic assisted sawings were represented. Then K9 glass and quartz glass were machined by ultrasonic assisted sawing, during the process the effects of ultrasonic vibration on sawing force and sawing energy were tested. Experimental results show that, compared with common sawing method, apart from influence of processing parameters, ultrasonic vibration can reduce the sawing forces in the processes of K9 and quartz by 30%—50% and 50%—65% respectively, and the specific energies accordingly by 30%—45% and 50%—60%. Radial ultrasonic vibration-assisted sawing breaks the material slightly and reduces the sawing force and sawing energy, therefore can promote sawing efficiency of optical glass materials and improve processing quality.

On the basis of Arrhenius theory and molecular vibration theory, the elastic and hyper elastic contact among the soft polishing particles, fused glass and the polishing pad was analyzed, then the material removal mechanism of fused glass using soft particles in polishing process was explored. According to the theoretical research mentioned above, a lots of polishing experiments were carried out and a material removal rate model was established. Theoretical calculation and experimental results show that the material is mainly removed by the interfacial tribo-chemical effect between polishing particles and fused glass in chemical mechanical polishing. The depth of a single particle embedding into the fused glass is 0.05 nm and the material removed by a single particle is a molecular scale. The superficial molecules of fused glass are easier to gain enough energy to implement chemical reactions, so that the materials could be removed easily. Moreover, the polishing pressure, the chemical reagents in polishing liquid, and the relative movement speed between the fused glass and the pad determine the material removal rate of fused glass.

The effects of various uncertain factors in the conduction path of a micro-expansion type heat switch on its thermal characteristics including OFF thermal resistance, ON thermal resistance and ON/OFF ratio were researched using parameter sensitivity analysis method. By comparing with the property experiment, the validity of heat switch finite element thermal model was verified. Based on the model, the relevance between thermal conductivity of structural components, thermal contact conductance of mating surfaces and OFF thermal resistance, ON thermal resistance and other thermal characteristics was analyzed. Then, the sensitivity of uncertain factors was classified by the absolute/relative variation of performance indexes. Research shows that the thermal conductivity of positioning shaft is the sensitive parameter about OFF thermal resistance and ON/OFF ratio, and the sensitivity indexes are 6.716 m0.5·K/W and 5.129 m0.5·K0.5/W0.5 respectively. The thermal contact conductance between cold side and disc is the sensitive parameter about ON thermal resistance, and the absolute variation and the sensitivity index are 1.865 K/W and 0.267 m·K/W respectively. The thermal contact conductances of other mating surfaces are the insensitive parameters about ON thermal resistance. Moreover, the shaft thermal facet-contact conductance is the sensitive parameter about OFF thermal resistance and ON/OFF ratio, and the absolute variations (sensitivity indexes) are 56.495 K/W (0.307 m·K/W) and 32.936 (0.235 m·K0.5/W0.5) respectively. These conclusions could provide the targeted reference for the structure-performance optimization of micro-expansion type heat switches.

To handle the high heat load obtained by photon absorbers located in the front-end of Shanghai Synchrotron Radiation Facility (SSRF), the structure design and optimization of photon absorbers were researched. The dispersion strengthened copper called GlidCop AL-15 was used to manufacture the absorbers. Direct water cooling and grazing incidence structures were used to improve thermal controlled-release ability of the front-end photon absorbers. The Petukhov formula and Darcy-Weisbach formula were selected to optimize cooling water channels. After thermal analysis with ANSYS for the temperature and thermal stress distributions of photon absorbers with different structure parameters, the structure optimization parameters of photon absorbers were determined. It shows that the diameter of cooling channels is 6 mm, the distance of photon confining surfaces to cooling channel walls is 9 mm, corner radiuses of two adjacent photon confining surfaces are bigger than 2 mm and the directions of cooling channels are parallel to the beam approximately. As compared to the original ones, the maximum temperatures of the photon absorbers and their cooling channel walls have declined by 8% and 1/4 respectively, the maximum equivalent stresse is only by half of the original ones. These results entirely satisfy the design requirements of SSRF front-end.

As most of the Computer Aided Tolerancing tools can only deal with the CAD models with an ideal surface and can not reflect manufacturing errors in physics and geometry, this paper explores a multi-scale representation method for skin model shapes in the Geometrical Product Specification. A discrete data modeling method was proposed for the simulation of topographic errors of surfaces and section profiles of a product in macroscopic and microcosmic scales based on new-generation geometrical product specification. Firstly, a simulation method for multi-scale surface topographic errors based on discrete wavelet was presented. Then, discrete wavelet was used to simulate multi-scale surface topography errors for sampling data of the surfaces and section profiles of a part. Finally, multi-scale surface topography errors were composed and skin models for two-dimentional profile and three-dimentional surface were acquired. The simulation and experiment results show that the proposed method represents skin models with multi-scale surface topographic errors and the average relevant error between the results of Ra obtained by a white-light interferometer and the proposed simulation method is less than 4%. The results verify the correctness and applicability of the proposed method, and provide a valid way for more comprehensive representation of skin model in new-generation geometrical product specification.

The installation errors leaded by deflections from two axes of a measured encoder and a reference encoder were researched in the process of dynamic measurement to improve the accuracy and reliability of photoelectric encoders. The effect of installation errors on measurement accuracy of the measuring accuracy of the measured encoder was analyzed and the installation error formula and a error control range formula were derived. To reflect the actual measuring accuracy of the encoder by encoder dynamic measurement, the allowed ranges of the maximum deflection αmaz and the maximum height difference Dmax were given. The measurement experiments were performed based on a 21 bit reference encoder to measure 15 bit encoders, and measuring results and error curves were compared and analyzed under conditions of little, small, and severe deflections. Experimental results show that the installation deflection should be controlled lower than 0.36° for ensuring the measurement effectiveness of 15 bit encoders, The error formula and error control strategy proposed in this paper can be applied to different kinds of measurement systems with different accuracies and they have a great value to improve the accuracy and reliability of photoelectric encoder measurement.

In order to research the performance of off-axis reflective optical system against the dynamic environment, the random vibration and fatigue analysis is presented. The finite element model of optical system structures is established and its modal analysis is performed by the finite element software MSC/Patran. The boundary conditions are used as the connecting hole of the base frame which in the actual assembly. The analysis results are obtained by constraint to the each node, and it shows that the change of translation and rotation in three directions are very small. Content the accuracy requirement of the measurement system in the space environment. Finite element analysis of the optical system is carried out in the three directions random vibration load. The results show that the maximum stress of the optical system internal structure are 151, 267 and 280, respectively. According to the S-N fatigue curve with aluminum alloy A709, and the PSD Spectrum of stress response, made the fatigue analysis of off-axis reflective optical system against the dynamic environment with Palmgren-Miner assumption, the results meet the system requirements.

A two-degree-of-freedom cantilever beam piezoelectric generator was explored to improve the generation performance of the cantilever beam piezoelectric generator under the variety of the ambient vibration energy sources. The theoretical model of the frequency characteristics of the two-degree-of-freedom cantilever beam piezoelectric generator was established and finite element analysis was performed for the proposed theoretical model. The theoretical results show that the theoretical analysis and finite element simulation are in agreement well. A numerical simulation was carried out for the frequency characteristic model of the two-degree-of-freedom cantilever beam piezoelectric generator and the results show that the ratio of the 1st modal frequency to the 2nd modal frequency will be a minimum value with the increase of the length ratio, width ratio, thickness ratio and the mass ratio, and the minimum value of the ratio of the 1st modal frequency to the 2nd modal frequency can be obtained at the length ratio of 0.8, width ratio of 2.0, thickness ratio of 1.0, and the mass ratio of 0.5. The results demonstrate that the frequency-band of the two-degree-of-freedom cantilever beam piezoelectric generator is expanded by optimizing the structure parameters to reduce the distance between the 1st modal frequency and the 2nd modal frequency. Finally, the two-degree-of-freedom cantilever beam piezoelectric generator was designed and the broadband generation performance of the generator verified.

According to the performance requirements of a high-resolution space camera for the bottom support structure, a flexible and damping support structure composited by a fillet feet frame and a straight beam was designed. Firstly, the bottom supporting structure of the space camera was designed based on the request of a satellite structure, and a optimized design model for the random response was established. The flexible link for the leg of two-feet frame structure was proposed with the size optimization technology, and the minimum thickness of the flexible link is 2.5 mm. Then, the support structure at the bottom of the camera was analyzed in engineering. The analysis results show that the weight of support structure components is 1.26 kg, and the fundamental frequency is 1 624 Hz. Finally, the support structure components of the space camera were tested by the random vibration test, obtained results show that the structure joint maximum response RMS value of the camera is 21.4 grms, and the random response maximum relative magnification is 0.93, satisfying the requirement of the support structure vibration of the space camera. These results verify the reliability of the design and analysis in this paper and provide a guiding for design of camera support structures of similar satellites.

As the damages on nonmetallic pipes, especially early damages, are difficult to be detected by ultrasonic guided wave, this paper proposes a nonlinear ultrasonic guided wave with signal delay to detect and localize the defects on nonmetallic pipes. Based on the nonlinear ultrasonic wave theory, the damage states of nonmetallic pipes were analyzed and an incentive method with mixed signals from the same end of the signal delay was developed to generate signal delay according to different speeds of the mixing signals and to implement nonlinear modulation. The instantaneous characteristics of delay signal were extracted by HHT(Hilbert-Huang Transformation), and damage location was achieved by analyzing different nonlinear modulation groups with signal delay. PVC(Polyvinyl chloride) pipes were used for experiments. In intact condition, the standardized reference values of signal delay groups is 0.518 8. In damage of one crack, standardized value of signal delay groups is 0.593 7 and the relative error is 3.277%. Moreover, in damage of two cracks, the standardized value of signal delay groups are 0.593 7 and 0.607 3, and the absolute error is less than 4mm. Compared to the wavelet envelope location approach, the relative error with one crack rises to 36.4%. These results turn out that the approach proposed in this paper is effective and accurate for the damage detection and location of nonmetallic pipes, and is available for the multi-damaged pipes.

To efficiently create the ultra-smooth surface of brittle crystals, an ultraviolet induced nanoparticle colloid jet machining system was established and the interaction mechanism between the nanoparticles and the surface of a workpiece in the process was investigated. Firstly, the characteristics of TiO2 nanoparticles and monocrystalline silicon surface used in the experiment were measured and investigated. Then, the plane-wave pseudopotential calculation method based on first-principles was used to study the geometrical structures and formation energies of TiO2 molecular cluster in chemically adsorbing on hydroxyl monocrystalline silicon surface. Finally, adsorption experiments of TiO2 nanoparticles and monocrystalline silicon surface were carried out. Calculation results show that the OH is chemically adsorbed on TiO2 cluster and silicon surface, respectively. In the adsorption process between TiO2 nanoparticles and silicon surface, new Ti-O-Si bonds and H2O molecule are formed to reduce the system energy. Infrared spectral experiment results also show that there exits a new generation of Ti-O-Si bond between the interfaces of TiO2 nanoparticles and silicon surface. The new chemical bond between the interfaces satisfies the chemical reaction mechanism in the process of ultraviolet induced nanoparticle colloid jet machining.

An optimization design method for elliptical flexure hinges is researched. As the traditional calculation formula for the stiffness of elliptical flexure hinges is more complex, this paper deduces a approximate theoretical formula by nonlinear fitting method with power function. Based on the approximate theoretical formula, it analyzes the precision characteristics of the flexure hinges and their maximum stresses at working. Then, the global optimization solver GlobalSearch and local optimization solver Fmincon are used to design optimally the maximum stiffness of an elliptical flexure hinge at a working direction. Finally, the applicability of the approximate theoretical calculation equation and the accuracy of the optimization results are assessed by comparison with the results from finite element analysis and experimental data. The results show that the relative errors between the finite element simulation, experimental data and the approximate theoretical calculation for the stiffness of elliptic hinge are within 5%. It concludes that the method avoids establishing the complex finite element mode and the processes of calculation and modification, and greatly improves the design efficiency. Moreover, it can obtain the maximum stiffness of the elliptical flexure hinges by optimization calculation.

According to the control requirements of the active reflector surface in the 110 m radio telescope at QiTai(QTT) Xinjiang, a new displacement actuator and a new displacement control system were designed and manufactured and then their characteristics were tested by a dual-frequency laser interferometer in the micro-displacement laboratory. The displacement actuator was designed by a scheme of high precision worm and roller screw structures, and the displacement control system was based on a ARM micro-processor. Finally, the S curve acceleration control methods were used to design the hardware platform and software algorithm for the active reflection surface of the control system. The test experiments were performed based on the laser metrology system on an active reflector close-loop antenna prototype for large radio telescope. Experimental results indicate that it achieves a 30 mm working stroke and 5 μm RMS motion resolution. The accuracy (standard deviation) is 3.67 μm, and the error between the determined and theoretical values is 0.04% when the rated load is 300 kg, the step is 2 mm and the stroke is 30mm. Furthermore, the active reflector integrated system was tested by the laser sensors with the accuracy of 0.25 μm RMS on 4-panel radio telescope prototype, the measurement results show that the integrated precision of the active reflector closed-loop control system is less than 5 μm RMS, and well satisfies the technical requirements of active reflector control system of the QTT radio telescope in 3 mm wavelength.

For requirements of the mirror in a space remote sensor for support function, a compound support structure used in the mirror with a large aperture in the space field was designed. The compound support structure includes a peripheral support composed of an A frame and a tangential pull rod and a back support composed of three groups of whiffletree structures. The support principle and engineering realization of the compound support structure were researched. Then, the design idea of function allocation and index allocation was used to design the compound support structure. The statics and dynamics simulations were carried out on the design result by the finite element analysis, and the relative test was performed on the actual mirror support component. Experimental results show that the surface shape error of the mirror with the compound support structure is better than λ/50(λ=632.8 nm), the rigid body displacement of mirror and the dip angle are smaller than 0.01 mm and 2″ respectively, and the mass of mirror component is less than 50 kg. Furthermore, the component has a reasonable modal distribution, and the fundamental frequency is 161 Hz, higher than the requirement of 120 Hz. The simulation and test results demonstrate that the compound support structure has good support effects, which meets the demand of space remote sensors for high reliability and high stability.

The experiments and modeling of thermal error compensation for the spindle system of a Computer Numerical Control (CNC) lathe were researched. A thermal error compensation model for the Spindle system of CNC lathe at axial and radial directions was established to enhance its error compensation ability and to improve the machining precision. A test platform for the thermal error of the spindle system was built. The five point method was used to test the thermal error of the spindle system, and a thermocouple and a infrared thermal imager were taken to measure the temperature changes of the spindle system. Then the gray comprehensive correlation analysis method was used to identify the temperature-sensitive measurement points and to construct thermal error prediction model based on re-sampling step particle swam optimization to evaluate the model effect. The prediction results on the thermal error compensation model based on re-sampling step particle swam optimization show that the axial residual thermal error is -1.29 μm—1.55 μm, and the modeling accuracy is 9504%. The thermal residual error along y direction is -4.68×10-6°—9.66×10-6°, and the modeling accuracy is 91.26%. The thermal residual error along z direction is -5.83×10-6°—8.59×10-6°, and the modeling accuracy is 93.24%. The research shows that the thermal error compensation model has high precision and a strong engineering application value.

The image fusion of infrared and visible light is susceptible to noise and the target information is weakened easily. Therefore, a new fusion algorithm based on target area extraction and compressed sensing was proposed. Firstly, the infrared image was detected in a salient region at frequency-tuned domain to obtain a corresponding salient map. Under the guidance of the salient map, the infrared target area was extracted together with region growing method to effectively overcome the effects of noise and complex background interference on target segmentation. Then, non-subsampled shearlet transform was adopted to decompose the source images and the high and low frequency sub bands in the target and backgound regions were fused respectively. Finally, a new fusion rule was proposed based on multi-resolution singular value decomposition and compressed sensing, and the fused image was reconstructed by the non-subsampled shearlet inverse transform. As compared with the other algorithms, experimental results show that the algorithm highlights the target area, preserves the details of the source images and suppresses the noise interference. The image fusion quality evaluation indexes including information entropy, standard deviation, mutual information and transferred edge information have increased by 3.94%, 19.14%, 9.96% and 8.52%, respectively.

As the accuracy and stability of a blood glucose level model is affected by the noise in near infrared non-invasive blood glucose detection process, an improved complete ensemble empirical mode decomposition method with adaptive noise was proposed for denoising of near infrared spectroscopy signals. Meanwhile, a mode selection method based on Frechet distance combining with the feature of curve curvature was proposed for the selection of Intrinsic Mode Functions(IMFs). Firstly. the complete ensemble empirical mode decomposition method with adaptive noise was introduced in the denoising processing of near infrared spectroscopy, and the basic principles and concrete realization processes of empirical mode decomposition, ensemble empirical mode decomposition, complementary ensemble empirical mode decomposition and the complete ensemble empirical mode decomposition based on adaptive noise were described. Then, an improved complete ensemble empirical mode decomposition method with adaptive noise based on curvature and discrete Frechet distance was applied in denoising for simulation signals and spectral signals, and their standard deviation and the Signal to Noise Ratio(SNR) were taken as the evaluation indexes. The simulation and experimental results show that the standard deviation of the improved method based on curvature and discrete Frechet distance in the near infrared spectral signal is 0.179 4, and the SNR is 19.117 5 dB, which extracts useful information, realizes the separation of signal and noise, and improves the quality of reconstructed signals. The proposed method has a good adaptability to effectively identify and separate the signal and noise components.

A novel fusion method of infrared and visible images was proposed based on Non-subsampled Dual-tree Complex Contourlet Transform(NSDTCT) and sparse representation to overcome the shortcomings of traditional image fusion method based on wavelet transform. With the proposed method, morphological transform was used to deal with source images, and then the source images were decomposed by the NSDTCT to obtain the low frequency sub-band coefficients and high frequency sub-band coefficients. According to the different characteristics of the low and high frequency coefficients, an Improved Sparse Representation (ISR) fusion rule was proposed for the low frequency sub-bands; Then, the improved spatial frequency was used as the external input of a pulse coupled neural network, and a fusion method based on the improved adaptive dual channel pulse coupled neural network (2APCNN) was presented for the high frequency sub-bands. Finally, the fused image was obtained by performing the inverse NSDTCT. Experimental results indicate that the proposed method outperforms the conventional image fusion methods in terms of both objective evaluation criteria and visual quality. As compared with conventional NSCT-SR method, the fusion quality indexes, Mutual Information(MI), Mount of edge Information(QAB/F ), Average Gradient(AG) and Standard Deviation(SD) have increased by 9.89%, 6.39%, 104.64%, 55.09%, and 953%, 17.77%, 95.66%, 52.89%, respectively.

As rail images show uneven gray distribution, general image segmenting methods can not accurately segment rail images. To address this issue, this paper presents an improved Otsu method using weighted object variance(WOV) for rail image segmentation to separate the defect from its background. Firstly, the property of a rail image was analyzed and the problems of the Otsu method and other global threshold methods for segmenting rail images were summarized. Then, the Otsu method was improved. By taking the cumulative probability of defect occurrence for the weighting, the object variance of between-class variance was weighted, and the threshold will always be a value that locates at two peaks or at the left bottom rim of a single peak histogram. Finally, the misclassification error (MCE), the detection rate and false alarm rate of the defect image were calculated to validate the effectiveness of proposed method. The experimental results demonstrate that the improved Otsu method accurately segments various kinds of rail images and the MCE value is close to 0. As comparing to the Otsu method, other improved Otsu method and maximum entropy threshold method, the proposed method provides better segmentation results, the detection rate and false alarm rate for the rail defected image are 93% and 6.4% respectively. It is suitable for the applications in machine vision defect detection in real time.

Traditional moving target detection under a moving base has a problem of larger background interference, and its detection accuracy is effected by the noise interference. This paper proposes a moving target detection method under the moving base by using orthogonal Fourier transform and kernel-grayscale chart to overcome the influence of a larger illumination change and background noise on moving target detection accuracy. Firstly, the evaluation function was introduced the selection of a feature matching block to implement the sub-block matching of video backgrounds. Then, global motion compensation parameters were estimated by using a phase-correlation algorithm based on orthogonal Fourier transform, and each Gaussian kernel value of each sub-block of the image was calculated to build a nuclear function-gray chart and to determine the area of moving target according on the change of the adjacent frame Gaussian kernel value. Finally, the image sub-block with moving target was divided and processed, and the moving target detection was implemented. The simulation in comparison with conventional moving object detection algorithm shows that when the evaluation coefficient in the evaluation function is set to be 0.7, and inter tile similarity threshold to be 0.3, the algorithm can effectively inhibit the background interference from illumination changes and background noise and can detect the moving target under the moving base. The algorithm has fast calculation speeds and meets real-time requirements of engineering.

To improve the usability of a foggy video, an improved video defogging method based on fog theory was proposed. By using dark channel prior knowledge, Retinex method and image fusion, the method applies the values of global atmospheric light and a medium transmission map estimated from the video backgrfound image to defogging of all the video frames. The effects of the defogging for the video image were evaluated by three methods in subjective qualitative evaluation, objective quantitative evaluation and operation speeds. Experimental results demonstrate that the proposed method runs at 5.45 frame/s for a video image of 480×640, and it not only obtains a fast processing speed but also effectively avoids color jump during the process of restoring image. As the modified method uses the interval estimation to estimate the value of global atmospheric light, and combinates image restoration and image enhancement to obtain the value of medium transmission map, it improves the visibility and contrast of restored video image effectively as well as color effect as compared with the traditional video defogging methods.

For the auto landing precisely of an Unmanned Aerial Vehicle(UAV), the longitudinal control law for the auto landing of the UVA was designed based on Adaptive Internal Model Control (AIMC) principle. By taking a small wheeled UVA as a working platform, the longitudinal nonlinear model was decoupled and linearized. Then, the ground speed and sink rate were selected as control targets and longitudinal control law was designed based on the AIMC and applied to control system design. The filter parameter was adjusted to improve the dynamic characteristics of the system and the model was identified to enhanced the robustness of the system. The AIMC system was simulated digitally under the conditions of ownwind or headwind in a speed of 6 m/s, and the results show that the landing precision of system is in a scope of 30 m for forward or backward directions. Finally, a hardware test platform was established to verify the simulation results and the hardware-in-loop-simulation (HILS) proves the harmony and integrality of the system.

Because the boundary pixels are easy to be classified as a background in the multi ship target detecting processing, this paper proposes a multi-ship saliency detection method based on patch fusion by color clustering. Firstly, this method detects the color similarity of the pixels in the neighbourhood, and the adjacent pixels with the similar color are gathered as an image patches. Then, the image patches are expanded to make them include some pixels of other patches, so as to enhance the contrast value of the pixels of patches. Then, edge pixels are marked in the background index to calculate the saliency ability of the pixels in image patches and the threshold segmentation method is used to obtain the saliency region of the target. As the image patches have the features of partial overlap, the weight values are used to fuse the saliency images with the partial overlaps, so that the saliency detection results on a whole image for the multi-ship targets are obtained. The experimental tests are carried out for the multi-ship target images, and the results from the proposed algorithm in this paper and the current advanced detection algorithms are compared. The results show that the proposed method based on patch fusion by color clustering has the recall rate more than 78%, the accurate above 92%, and its comprehensive evaluation index Fβ is more than 0.7. Both for comparisons of the single index or the entire indexes in this experiments, the algorithm is superior to other methods.

A Fractional Lower Order Cyclic Correlation (FLOCC)-based MUSIC method was proposed for estimation of the Direction of Arrival (DOA) and polarization parameters for a single electromagnetic vector sensor in mixed α and Gaussian noises and cycle stable interference signals. On the basis of the cyclic stability of signals, the FLOCC function was used to suppress the cyclic stationary disturbance signal and the mixed α and Gaussian noises. Then, MUSIC method was used to estimate the DOA and polarization parameters of the single electromagnetic vector sensor, and the mutual independence between the DOA parameters and the polarization parameters was used to simplify the four dimensional search of traditional MUSIC method into two times of two dimensional search to reduce the calculated amount of the algorithm. The proposed algorithm was compared with the traditional MUSIC method based on fractional lower order moment in the simulation. The results show that the proposed method can sufficiently suppress any of cyclic stationary disturbances with different cycle frequencies. When the mixed signal to noise ratio of α and Gaussian noises is 0 dB and the signal to interference ratio is 3 dB, the root mean square error of the estimation of DOA and polarization parameters is 0.3° and 0.7 °, respectively, being superior to that of the traditional MUSIC method.