As workspace Measurement and Positioning System(wMPS) has lower calibration efficiency,complex algorithms and relying on auxiliary equipment,this paper presents a novel self-calibration method by using inter-scanning method.According to the multi-place intersection theory and system application characteristics,the automatic calibration was implemented by a inter-scanning technology on receivers mounted on the laser stations whose coordinates were known in advance.On the basis of two laser stations,the mathematical theory of the method was described,and the optimal algorithm(adjustment model) based on the geometrical constraint characteristics of the system was given in detail.The method was verified on a wMPS experimental platform developed by Tianjin University and was compared with the standard rule calibration method.The experimental results demonstrate that the inter-scanning method is an efficient solution for calibration of the stations,and the accuracy of the system achieves 0.6 mm in the space 5 m away from the station.Thus,the method proposed improves the calibration efficiency of the system while maintaining the measurement accuracy.

An angular-spectrum method with a scaling factor between the observation and the source plane was proposed for the laser propagation in an optical system to evaluate its performance and to analyze its tolerance.As the laser diffraction propagation in the optical system could be calculated by the Collins integral formula,the formula coordinate was transformed and an angular spectrum method was derived by coordinate substitution.Then,a scaling factor was introduced to make the choice of the observation-plane more flexibility and the calculation of the laser propagation more accurate.A laser optical system was designed,and its tolerance was analyzed by the angular-spectrum method.The evaluating criterion was the laser spot radius in the far field,which was defined by 86.5% Power in Bucket(PIB).Experiments show that when the radius of the laser spot is 0.8—1.4 mm in a distance of 90 m,the expected value calculated by the tolerance analysis is 0.92 mm and the measured result is 101 mm.Moreover,when that is 0.42—0.73 mm in the distance of 47 m,the expected value and the measured result are 0.48 mm and 0.46 mm,respectively.Both the experiment results match the data of the tolerance analysis well.The focal shift for laser propagation in the optical system was validated by the tolerance analysis.The theoretical analysis by the proposed method is verified experimentally,which confirms the feasibility proposed method in design of laser focus optical systems.

The performance of laser fuze is vulnerable to be scattered and absorbed by atmospheric aerosols while it propagates in atmosphere.In this work,the backscattering polarization characteristics of a pulsed laser in water fog were researched by using Mie scattering theory and Monte Carlo simulation.By simulating 19 kinds of fog particles with diameters of 1—10 μm,the Mean Contrast of Polarization(MCOP) of backscattering laser was obtained for typical wavelengths and diameters.An experimental system for the backscattering polarization characteristics of a coaxial pulsed laser was established in water fog.Five kinds of man-made fog particles with different diameters were obtained by changing the concentration of an ultrasonic humidifier.The man-made fog particles were measured experimentally,and the results show when fog particle diameters are in 1—10 μm,the MCOP of laser backscattering is from 0.30 to 0.65.Experimental results agree well with the simulation data,thus verify the validity of laser backscattering theory model and Monte Carlo simulation,and provide a method for laser fuze anti-interference of clouds and fogs.

The micro-forming experiments of Ti foils were performed under a laser driven flyer indirect shock with high strain load features to overcome the micro-forming problems of difficult deformed materials.The forming properties of Ti foils under the laser indirect shock were explored from three aspects,the integrity of flyer,the fitability and the ratio of thickness to thinning of workpieces.In this experiment,the mold was fabricated by micro Electrical Discharge Machining(micro-EDM) and curved surface grinding.AISI 1090 die steel was used as the material of mold.The Ti foils with the thickness of 20 μm were employed as flyers.Furthermore,Ti foils with the thickness of 35 μm were used as workpieces.The flyers and workpieces were observed under a KEYENCE VHX-1000C digital microscope.The results indicate that the flyers show good integrity and provides a uniform shock pressure,so that the workpieces with good surface quality and fitability are fabricated.The cold-mounted technique was used to characterize the thicknesses of workpieces and to discuss the ratio of thickness to thinning,which shows that the maximum thinning rate is 19.8% and the minimum thinning rate is 2%.The results demonstrate that the workpieces have uniform thickness distribution.The laser indirect shock micro-forming technique has good forming properties on difficult deformed materials and reduces the thickness thinning effectively.

Due to the limits of light sources,the sizes of rotating platforms and the propagation of assembling errors,traditional methods of lens centering are not suitable for the assembly of large-aperture and multi-lens optical systems.Thus a new high-precision mechanical measurement method for lens centering was proposed based on a three Coordinate Measuring Machine(CMM).Principles and algorithms for measuring off-centering of the large aperture lens using the high-accuracy CMM were introduced.In the measurements,the angle between the optic axis of lens and the reference axis was calculated after the figure fitting of the measuring points,and then the centering of deviation was calculated.The method was verified by the assembling of a long focal length and large aperture imaging system.The assembling result shows that the lens off-centering is 6.47″ and the repeatability error is(1.16×10-4)″.As changing the optical measurement into a mechanical measurement,this proposed method ensures the accuracy,reduces the difficulty and improves the efficiency of lens assembly.It is able to be applied to the high-precision assembly of large aperture transmitting optical systems.

To measure the dynamic deformation of an object surface in real time accurately,this paper proposes a spatial carrier phase-shifting shearing speckle system based on a slit aperture.A Michelson interferometer was used to generate a shearing distance and a spatial frequency shift by tilting a small angle in one of the two mirrors.A slit aperture was used to control the speckle size and the spatial spectral width.The Fourier transform and inverse transform were applied to accurate calculation of the phase and to obtain the phase distribution by using only a single image.Finally,the shearing speckle system was used to measure the dynamic deformation of a circumferentially fixed thin aluminum plate with a point load at the center.The effects of optical system parameters on the measuring results were analyzed.The experimental results show that when the shearing distance is 25 mm and the slit aperture size in X direction is 1 mm,it is possible to obtain a better phase-map quality by using a higher spatial frequency CCD camera with a pixel size of 4.65 μm×4.65 μm and an image lens with a focus length of 8 mm.It demonstrates that the shearing speckle system obtains the information of deformation in real time under a capturing rate of 25 frame/s and an angle of view field 43.6°,and the measurable range of displacement peak value is from 0.5 μm to 30 μm.

A double-angle polarizing atmospheric corrector(DPAC) on an airborne platform is established for the quantification of remote sensing data.This sensor acquires spectral,angle and polarization information in image areas by time synchronization and space covering to implement the high-precision retrieval of aerosols and water vapors.Then,by taking these atmospheric parameters obtained by atmospheric retrieval as an input,the high-precision atmospheric correction for optical remote sensing images is achieved with a radiation transfer model.The DPAC has two detecting directions,one is along the nadir angle(0°) and the other is a forward angle(55°).It covers 8 wavebands ranging from 0.49 μm to 2.25 μm,among which five wavebands are designed for polarizing measurement.To overcome the polarization measurement errors caused by detection target inconsistent,the higher precision and integrated structure is designed to ensure the field overlap accuracy of polarization detection channels.The results of lab calibration and test show that the viewing field coincidence is better than 95% and the polarization accuracy is better than 1%(DoLP=03),which meets the requirements of the DPAC for specifications.

The applications of neutron radiograph were introduced.As adding directly neutron-absorbing atoms into Micro-channel Plate(MCP) glass would make the MCP sensitive to neutrons,and the advantages of a MCP event counting imaging detector would be successfully extended to the imaging detection technologies,this paper explores the thermal neutron sensitive MCPs.By adding directly 3 mol% natGd2O3 into MCP glass composition and using a conventional fabrication process,the large format neutron-sensitive MCPs with diameters of 50 mm and 106 mm were fabricated and the high efficiency event-counting thermal neutron imaging experiments were completed by using this Gd doped neutron-sensitive MCPs.The theory and experiments verify that this 3 mol% natGd2O3 doped neutron-sensitive MCP realizes the detection efficiency of 30%—50% for thermal imaging or cold neutrons.This work now is further proceeding to develop a sealed neutron sensitive MCP intensified tube,because the compact neutron camera based on a hybrid sensor configure via optical couple to a CCD or a CMOS camera is a promising approach to high temporal and spatial resolution neutron radiographic nondestructive test technology.

To quickly and accurately solve the path length corresponding with the oxygen absorptivity of oxygen absorption passive ranging technology,this paper explores the mathematical model on oxygen absorptivity and path length.Firstly,the strong correlation of different absorption coefficient distributions under different temperatures and pressures was verified and the relation between absorption coefficient distributions and temperatures,pressures was given.Then,the mathematical model on oxygen absorptivity and path length was established by using Correlation-K Distribution(CKD) method and surface Earths model.Finally,the theoretical analysis and experimental checking were performed.The results show that this mathematical model not only well adapts to altered atmospheric models,but also quickly and accurately calculates the oxygen absorptivity curves of specified path and the target distances.The relative ranging error is 4.4% under average math mode,but the relative error is only 1% after eliminating background and reducing measurement errors.The conclusion shows that the math mode solves the ranging inverse problem of the oxygen absorption passive ranging technology,and provides some theoretical supports for the further optimiz and application of passive ranging technology.

A non-contact three coordinate measuring system was established to implement the measurement of 3D free-form surfaces accurately.A laser sensor was installed on the Z axis of a coordinate measuring machine via a probe head with two rotary axes,whose direction could be adjusted according to the shape of the measured surface.For the purpose of enabling the sensor to realize measurement functions in every orientations,a calibration method of laser beam direction based on a spherical target was proposed,and its principle was analyzed in detail.In the calibration procedure,the sensor moved in an equal distance along X,Y and Z axes and then equation sets were set up based on the bundle equations to compute the unit direction vector of the laser beam.Finally,a cube block with known dimensions was measured by the system to test the repeatability of the measuring system.The experimental result indicates that the measuring uncertainty of the system is 0.048 mm,which shows the good practicability of the calibration method.When the system was used to measure a sphere with a known diameter,the errors in every orientations are all smaller than 0.05 mm,which manifests that the calibration method proposed meets the requirements of reverse engineering.The method shows higher calibration precision and repeatability,and lays a basis for fast scanning of 3D free-form surfaces.

To find a suitable method for evaluating electromagnetic shielding properties of metallic mesh coatings,the shielding effectiveness of a general metallic mesh coating was explored.Firstly,a set of the formulas commonly used to calculate the photoelectric characteristics of metallic mesh was analyzed.It points out that the infinite conductive material assumption of formulas is not reasonable,and these formulas can not accurately forecast the electromagnetic shielding effectiveness of thin-film metallic mesh.Then,according to the theory that the shielding effectiveness is associated with the ratio of induction voltage to resistance,a method to estimate the shielding effectiveness of thin-film metallic mesh was proposed by using the shielding effectiveness calculation formula of the continuous conductive film with the square resistance,and the estimation concrete steps were given.Finally,three specimens of thin-film metallic meshes were prepared by the laser direct writing process to test the validity of the method.The results for 30 MHz to 1 500 MHz band show that the highest electromagnetic shielding efficiency of specimens is 30 dB by the coaxial test method,and the calculation value is 31.2 dB by using the method proposed in this paper,as the calculation value is 75 dB by commonly used method.These data indicate that the commonly used electrical characteristic calculation formula of metallic mesh can not accurately evaluate the electromagnetic shielding effectiveness of thin-film metallic mesh,and the method proposed in paper is convenient,accurate and feasible.

Based on the resonant coupling principle between the defect mode of a ring resonator and the line-defect waveguide,a four-channel Wavelength Division Multiplexing(WDM) system was designed by using the 2D triangular lattice photonic crystal.This system was composed of a line-defect waveguide,ring resonators and 60° bend waveguides.The band structure of the line waveguide was investigated by the plane-wave expansion method.The transmission characteristics of light wave with different frequencies in the system were simulated by the finite difference time domain method,the effects of factors on output efficiency and quality factor were analyzed and the system was improved.The analysis shows that the resonance frequencies depend on the radius of the dielectric rods.It is demonstrated that the transmission efficiencies of the system is improved greatly by changing the shapes of dielectric rods in the coupling region and adding the reflection dielectric rods at the end of bus waveguide.The numerical results indicate that the system has the ability to achieve the WDM for different wavelengths,and the transmission efficiencies of all the resonance wavelengths are still above 90%.The system is a simple structure and easy to be fabricated and processed.Moreorer,it has a smaller size,and could be large-scale integration.

According to the requirements of optical fields for metal micro devices with higher aspect ratios,a metal micro-grating with the high aspect ratio was fabricated on a metal substrate by using the UV-LIGA technology.The “exposure step by step” and “development once” were used to fabricate a SU-8 thick photoresist mold with high aspect ratio to overcome the technologic difficulty in fabrication processing.For the defects of electroforming layer caused by long operation time,the fractional electroforming and other methods were adopted to obtain the electroforming grating structure..At the same time,the line width compensation method was taken to solve the problem that line width of SU-8 photoresist mold was reduced by swelling.In the process of stripping photoresist after electroforming,the ultrasonic method and soaked method were alternately used.Finally,the metal micro-grating with a period of 130 μm,and a size of 900 μm×65 μm×243 μm was fabricated.The high aspect ratio of the metal micro-grating reaches 5,and its relative error on overall dimensions is lower than 1%.Moreover,the surface roughness of metal micro-grating is lower than 6.17 nm.This research breaks the height limitation and substrate fragile of the exciting fabrication methods for metal micro-gratings with high aspect ratios.

To form enclosed microchannels in microfluidic chips,a bonding method suitable for a polymer microfluidic chip was proposed to overcome the microstructure collapse of hot bonding and the microwarp of microfluidic chip fabricated by hot embossing and to ensure the subsequent bonding.A PC microfluidic chip was used in the research.The heating pressure method was used to prepare bonding tendons in two sides on microchannels of the microfluidic chip and the chemical solvent acetone was used to dissolve the surface of PC wafer slightly.Then the PC wafer and the microfluidic chip with bonding tendons were fitted,pressured and heated,and the bonding process was implemented.The bonding mechanism was analyzed and the bonding process parameters were also optimized.Experimental results illustrate that dissolving time and bonding temperature influence the bonding quality obviously.The microfluidic chip with acceptable quality is achieved when the bonding temperature is between 80° and 90℃ and the dissolving time is between 35 s and 45 s.Entire bonding process just needs 3 minutes.As compared with traditional process,this bonding process has improved the processing efficiency greatly and it not only can be used for the microfluidic chip with different channel widths,but also is suitable for the microfluidic chips fabricated by other polymers.

As synchronous periodic vibration forces are induced by both uneven distributed mass and magnetic center offset when the active-passive hybrid magnetically suspended rotor rotates at high speed,this paper proposes an autobalancing method to remove the vibration forces.Firstly,the offset parameters of the passive magnetic bearing were calculated from the synchronous periodic control currents extracted in the zero-displacement control condition.Then a general notch filter was designed to inhibit the synchronous current and to obtain the synchronous displacement at the same time.After carrying out the feedforward compensations of active-passive magnetic bearing displacement stiffness force and the offset of the passive magnetic center,the synchronous period force component of the active-passive magnetic bearings was removed entirely.The method was verified by simulations and experiments,and compared with an algorism without passive magnetic center offset compensation.The simulations indicate that the synchronous force has reduced to 6% of the algorithm without passive magnetic center offset compensation.Experimental results indicate that the synchronous vibration acceleration has reduced to 23.3% of that without passive magnetic center offset compensation.Simulation and experiment results demonstrate the effectiveness of the proposed method and show that the method is effective for elimination of synchronous vibration force and realizes the automatic balance control for rotors.

A novel surface plasmon resonance(SPR) sensor coated with poriferous molecularly imprinted polymers(MIPs)was developed to detect the trace microcystin-LR in water.The method to detect the trace microcystin-LR in water was explored.Firstly,the in situ self-assembly method was used to synthesize a poriferous thin MIPs film on the gold-plated glass.The SPR chip to specifically capture the microcystin-LR was obtained.Then,based on the typical Kretschmann prism coupling structure,a new type of SPR sensor based on wavelength interrogation was constructed by utilizing the MIPs coated gold-plated glass as the sensing chip.The sensor was used to detect different concentration of microcystin-LR solutions and microcystin-RR solutions and to obtain its measuring ranges and specificity parameters.The result indicates that the sensor is sensitive to microcystin-LR and completes a quantitative determination with a dynamic measure range of 2.1×10-9—1×10-6 mol/L.Moreover,the sensor did not have obvious response to microcystin-RR,the analogues of microcystin-LR.It means that the sensor has special selectivity to recognize the microcystin-LR.

To obtain the vibration amplitude-frequency characteristics of a in-orbit space camera,a space camera vibration parameter detection method by using TDICCD mechanical assembly technique was presented.According to TDICCD mechanical assembly technology,the images of same scene were taken by a TDICCD overlapping area at different moments,then the images were compared by using gray projection algorithm to derive the relative offset.Finally,the offset data were fitted,and the vibration parameters of the space camera were obtained according to the fitting result.Experimental results show that frequency measurement relative error and the amplitude measurement absolute error are less than 0.5% and 1 pixel respectively for the one dimensional single frequency vibration;and those are less than 3% and 2 pixel respectively for one dimensional mixed frequency vibration.Moreover,for two dimensional vibration which are both single frequency vibration along and vertical to the scanning direction,the frequency measurement error and the amplitude measurement error are less than 1% and 2 pixel,Respectively.Experimental results demonstrate the correctness of detection methods,reach the purpose of detecting vibration parameters without additional facilities except the camera structure,and provide a data base for the subsequent image restoration.

Based on an inverse piezoelectric inchworm motor researched and manufactured before,the influence of balanced stiffness of a clamping body with triangulation amplification on its output displacement and the performance of motor was researched.The research results show that rotary displacement is resulted by non-balanced stiffness of the clamping body and the horizontal displacement is reduced also.Then because the rotary displacement and the performance of the inchworm motor are lower,the extent of releasing guide is reduced.For overcomming this problems,a method to balance the equivalent extent stiffness in two sides of a piezoelectric stack was proposed by adding a piece of metal board,and the dimension of the board was calculated by Finite Element Method(FEM).After adding a metal board,it demonstrates that the horizontal displacement and response frequency of the clamping body are increased and the guide is approximate to be fully released.The performance of the inchworm motor is advanced dramatically.After balancing the stiffness,the response frequency is 450 Hz,the highest driving force is 7 N and the highest velocity is 1.49 mm/s.

As the double-rod structure in ruling system of a large diffraction grating ruling machine can not meet its accuracy requirement,this paper designs a single-rod structure to substitute it.The reasons of bending error of indexing direction of quarts guide rail in the grating ruling machine were discussed and the method to reduce the error was analyzed.Meanwhile the rod structure and the stress on a saddle slider were analyzed.Then,based on the theory of bending deformation of material mechanics,the model of bending error in indexing direction of quartz guide rail was established.On the basis of this model,the bending errors of quartz guide rails on the double-rod structure and the single-rod structure were simulated.Finally,a frequency laser interferometer was used to measure the two feature points on quartz guide rail.Experimental results indicate that the bendings at the measuring points of quartz guide rail are reduced from 50.36 nm to less than 10 nm by using the single-rod struture.It concludes that the single-rod structure basically meets the requirement of large diffraction grating ruling engine for the measuring precision of 5—10 nm.

Giant magnetostrictive actuators show hysteresis and displacement nonlinear characteristics when they are used in the field of precision actuation control.To overcome the shortcomings,a kind of control strategy combined with the Cerebellar Model Articulation Controller(CMAC)feedforward inverse compensation and the fuzzy PID control was presented.A dynamic inverse model of the GMA was established with the CMAC on-line learning method to compensate the hysteresis nonlinearity of the GMA.A fuzzy PID controller was introduced in GMA to achieve the precision control of the GMA.Using this controller,the learning error of CMAC was decreased,the disturbance was eliminated and the tracking control performance of system was improved.The results came from simulation and experiments show that the control method can effectively reduce the hysteresis error and the tracking error of the system is less than 5% and the displacement tracking error is 0.58(mean square error).In addition,this strategy is characterized by learning and controling at the same time,so that the control system adapts to the changes in the dynamic characteristics of controlled object and has a stronger robustness.Meanwhile,it eliminates external interference effectively and improves its adaptive control performance.

To eliminate the hysteresis phenomenon between the photodeformation and the photovoltage of PLZT(Lead Lanthanum Zirconate Titanate) under the irradiation of high energy light,a novel photostrictive constitutive equation in multi-energy fields was established and the influence factors of the hysteresis phenomenon were investigated by experiments.Firstly,the light-thermal-electric-elastic coupling mechanisms of the photostrictive effect under a lighting were analyzed theoretically and the constitutive relationship of photostrictive effect was established.After that,a novel constitutive equation was obtained by the derivation of anomalous photovoltaic effect,thermal effect,pyroelectric effect,thermal expansion effect and piezoelectric effect.Finally,the photostrictive constitutive equation was validated through the temperature screening test and photostrictive static experiments.Experimental results indicate that the temperature rise of PLZT ceramic is the main reason of hysteresis phenomenon;and the variation trends of experiment curves are agreed well with the theoretical results,which confirms the reasonability of the theoretical model.Moreover,the photodeformation of the PLZT in the experiment takes about 10 s to reach saturation after eliminating the temperature rise.It shows that reducing the temperature rise effectively eliminates the hysteresis phenomenon and improves the response speed of photodeformation.The novel constitutive equation provides a theoretical basis for driving and controlling of PLZT ceramics.

For higher fabrication costs and poor consistency of electrochemical seismic sensors,a new structure for an electrochemical seismic sensor with planar electrodes based on Micro-electric-mechanical System(MEMS) was presented.A 2D calculation model for the seismic sensor designed was built.The key structure parameters,such as the widths of electrodes,the space between electrodes and the height of the channel which might affect the performance of the seismic sensor,were calculated and optimized by the multi-field coupling numerical simulation method with Comsol software.Through the MEMS surface processes and quasi-LIGA(Lithographie Galvanoformung Abformung) process,the MEMS based electrochemical seismic sensor with planar electrodes was fabricated and packaged.Finally,the characteristic experiments of the frequency response and the tiny-vibration testing for the sensor designed and the traditional seismic sensor based on precise-machining(MET 2003) were carried out.The experiments show that the frequency bandwidth of the sensor designed is expanded from 1 Hz to 30 Hz as compared with that of the MET 2003 and the consistency between the sensor designed and MET 2003 is achieved to 0.887.The noise level is less than 120 dB at 1 Hz.

As the primary mirror seeing of a ground based large aperture telescope is directly related to its image quality,this paper researches the effect of environments on the primary mirror seeing.Through theoretical analysis,it points out that the size of the primary mirror seeing will increase with the temperature change between the primary mirror surface and the environments.Then using thermal analysis software Radtherm,the temperature changes and temperature distributions of a 2 m SiC lightweight primary mirror were analyzed under two different conditions of natural convection and natural flowing.Finally,the some temperature experiments on the 2 m SiC lightweight primary mirror under the working conditions mentioned above were performed to verify simulation results.The experiment results indicate that it takes about 4 hours to reach temperature equilibrium with the environment for the primary mirror in case of natural convection with initial 6 ℃ temperature difference;however,it takes only about 1.5 hours in case of natural flowing with initial 8 ℃ temperature difference.It shows the greater temperature difference but much less consumed time.These means that when the thermal control system and control method are forced to the large-aperture telescope system to perform the convective heat control,the mirror seeing will be controlled in a reasonable range more quickly and more effectively,and more telescope observation time can be obtained meanwhile maintaining much better image quality.

Traditional measurement methods for optical displacement have higher demands for the environment and it is difficult to improve the manufacturing precision of measuring devices.Therefore,a novel linear displacement measurement method was proposed by using the alternating light field as measuring medium.On the basis of the method,a light Intensity orthogonal modulation type displacement sensor was designed.The method combined two electrical standing waves with orthogonal changes into the electrical traveling wave signals,then,it measured the time sequence of traveling waves to achieve the spatial displacement measurement.In order to explore the sensing mechanism of the sensor,the actual measurement model of the sensor was derived,and the influence of key factors associated with the sensing mechanism on the measurement error was analyzed in detail.According to the analysis of the measuring principle and model theory,a sensor prototype was developed and various critical factors effecting on measurement error levels were tested.Then,sensor structures and parameters were optimized.The experimental results show that measuring errors of the optimized sensor are controlled within ± 0.5 μm in the measuring range of 108 mm,which demonstrates that proposed method is a new displacement detection solution without demands for precise photolithographic processing.

As the precision of a photo-turntable control system using rotary inductosyn depends on the dynamic angular position measuring precision of a rotary inductosyn,this paper explores the system error of the rotary inductosyn.The error mechanism of rotary inductosyn was analyzed,and the system error of the rotary inductosyn was quantitatively and dynamically measured by using an experimental platform.Finally,the system error model of the rotary inductosyn was put forward based on the data processing and error mechanism,and the output signals from the rotary inductosyn were compensated by the error model.The software compensation method was verified and the experimental results for the rotary inductosyn with 720 poles,12 bits show that the dynamic angle measurement accuracy is improved from 11.25″ to 1.17″,while the angular velocity estimation accuracy is improved from 0.72(°)/s to 009(°)/s.The test results show that the proposed method improves the dynamic measuring accuracy of the rotary inductosyn significantly and satisfies the accuracy demands of photoelectric platform pointing control systems.

To improve the actuator stroke of laminated piezoelectric ceramic and to let it be with the ability of reciprocating symmetrical actuation,a diamond piezoelectric micro displacement amplification mechanism was proposed based on the triangle amplification principle.The laminated piezoelectric ceramic was taken as a driving element of the mechanism.On the basis of the triangle displacement amplification principle,a two-way active output on both sides of the equilibrium position was achieved while amplifying the output displacement of the laminated piezoelectric ceramics.A corresponding driving method was proposed to achieve the control of direction and magnitude of the output.The working principle of the mechanism was analyzed,and the geometric calculation results show that the magnification is 2.9,which is close to the simulation calculation magnification result 25 based on finite element model.A test prototype was developed to test the performance of the mechanism.The experimental results indicate that the maximum output displacement of the mechanism is 32 microns(±16 microns) when the driving voltage is 200 V and its amplification is 2.4 for the displacement of the laminated piezoelectric ceramic,which is close to the theoretical calculation.The experiment also shows that the signal frequency has a minor effect on the displacement output.The mechanism achieves both of the displacement amplifications and two-way movement outputs as desired.

A novel method based on region classification and multi-resolution transform was presented for the fusion of infrared and visual images to retain their spatial information and thermal target information and to improve their observability and intelligibility.The fusion process contained the following three steps.Firstly,infrared and visual images were fused by the Non-sampled Contourlet Transform(NSCT) to get lowpass subband coefficients and bandpass directional subband coefficients.Lowpass subband coefficients were fused by the region energy rule and the bandpass directional subband coefficients was fused based on the correlation rule of the bandpass directional subband coefficients.Then,the Structural Similarity Index(SSIM) between original images and intermediate fused image was computed.Based on the obtained SSIM,the images were classified in regions and the similarity region classification maps were obtained.Finally,to generate general and complementary regions,pixels of original images were classified by the threshold of similarity.In accordance with the concentrated similarity of different regions,the original images were fused for the second time and the final fused images were obtained.In this method,the general and complementary regions of infrared and visual images were distinguished effectively.The experimental results show that the method is better in fusing infrared and visual images than some current methods,such as NCST,Dual-tree Complex Wavelet Transform(DTCWT),Redundant Discrete Wavelet Transform(RDWT),and Discrete Wavelet Transform(DWT).As compared with the NSCT method in two group images,their quality indexes have been increased by 16%,85%,54%,36% and 18%,102%,84%,41%,respectively.

The visual salience extraction model only considers visual contrasting information and it does not conform to the biology process of human eyes.Therefroe,a hybrid model based on Improved Salient Region Extraction(ISRE) algorithm was proposed in this paper.This hybrid model consists of a salience filtering algorithm and an improved Pulse Coupled Neural Network(PCNN) algorithm.Firstly,the salience filtering algorithm was used to get Original Salience Map(OSM) and Intensity Feature Map(IFM) was used as the input neuron of PCNN.Then,the PCNN ignition pulse input was further improved as follows:the point multiplication algorithm was taken between the PCNN internal neuron and the binarization salience image of OSM to determine the final ignition pulse input and to make the ignition range more exact.Finally,the salience binarization region was extracted by the improved PCNN multiply iteration.Based on ASD standard data base,some experiments on 1 000 images were performed.The experimental results show that the proposed algorithm is superior to the five existing salience extraction algorithms uniformly in visual effect and objective quantitative data comparison.The results display that the precision ratio,recall ratio,and the overall F-measure of the proposed extraction algorithm are 0.891,0.808,and 0.870,respectively.In a real context experiment,the proposed algorithm gets more accurate extraction effect,which verifies that the proposed algorithm has higher accuracy and execution efficiency.

An adaptive filtering algorithm based on the quality of information was proposed aiming at the visibility of pulsars in pulsar navigation.According to the analysis of the number of pulsars observed and the quality of information received,the dimension of observation matrix was determined,and an improved Kalman filter was designed to be adaptable to the observation of the information changes.The observed information quality was defined,then filtering equation was constructed according to the definition of pulsar navigation to improve the accuracy and the adaptability of the pulsar.In order to improve the precision of linearization and discretization,Runge Kutta method was used to solve the two body dynamics equation with J2 perturbation.A simulation experiment was performed to verify the improved Kalman filtering algorithm.The experimental results show that after the initial error is corrected,the position precision is 40 m and the velocity precision is 0.019 m/s when one or two pulsars are observed for navigation within 10 000 s.The simulation results show that this filtering algorithm is effective and feasible.

To track the real changes of dynamic target DOA(Direction of Arrival) quickly and accurately,the artificial bee colony theory and a corresponding algorithm are used to optimize the likelihood function and to implement the real time tracking of dynamic target DOA.First,an adaptive subspace updating algorithm with a variable forgetting factor is proposed,which could adjust adaptively the weights of current and historical data in a covariance matrix according to the DOA change speed and could obtain a smaller stable error while a better tacking speed.Then,by making use of the maximum likelihood algorithm with superior performance,this method avoids the repetitious feature values and singular value decomposition in the subspace tracking algorithms.Finally,the artificial bee colony algorithm is used to optimize the likelihood function and to reduce the computation of the algorithm.Experimental results on sampling in singe snapshot indicate that the Root Mean Square Error(RMSE) of DOA estimation is 0.995 2° under tracking estimation two signal sources with a SNR of 0 dB.It satisfies the requirements of design for target tracking method in an array signal processing.

A correction method for distortion sequences was proposed based on affine transform and multilevel B-spline registration to overcome the image distortion and pixel deviation from the atmospheric turbulence.As the pixel deviation caused by turbulence is nonlinear and random,and the global motion caused by the imaging system movement might exist in practice,the correction method divided the pixel into two parts,the global motion estimation and the local non-rigid registration.The affine transformation was adopted to eliminate the global motion.The multi-resolution strategy was introduced to process pixel distortion and the multilevel B-spline was adopted to register the local motion.On the basis of the symmetry constraint cost function,the control point gridding was fined further to improve the B-spline accuracy by evaluating the regions of interest with the gradient method.Finally,limited-memory Broyden-Fletcher-Glodfarb-Shanno(L-BFGS) algorithm was used to minimize the cost function to obtain the pixel deviation and to complement the correction of image distortion.Experiments demonstrate that the proposed method effectively reduces the pixel distortion from the atmospheric turbulence even for noisy and blurred conditions.

A novel method to fuse infrared and visible images was proposed based on compressive sensing theory.The method combined Contourlet Transform(CT) with Wavelet Transform(WT) to increase the sparsity of transformed coefficients and also to improve sample patterns and fusion rules.Firstly,the original images were decomposed in a Contourlet domain,and orthogonal wavelet transform was applied to the high level decomposed coefficients.Then,the composite double radially sampling mode with different sampling rates in each decomposition level was used to perform the linear measurements of coefficients and to fuse the measurement values using different rules in each level.Finally,the fused image was reconstructed by using nonlinear conjugate-gradient solution.The experimental results demonstrate that the detail information of fusion image by proposed method is more salient than that of discrete wavelet transform fusion image when sampling rate is 0.5.As compared with WTCS method,the mutual information,spatial frequency and the visual information fidelity of fused image from proposed method are increased by 10%.

In consideration of the demands of image compression algorithm in space application fields for computer complexity,this paper proposes a new “run-length coding of first 1 bit” algorithm.In this algorithm,the first 1 bit plane and above bit planes of Discrete Wavelet Transform(DWT) coefficients are encoded by signed adaptive binary run coding algorithm presented in this paper,and lower bitplane is directly ouput as its bit value.To be compatible with a lossless compression,the algorithm uses a 97 integer wavelet transform recommended by Consultative Committee for Space Data System(CCSDS).Because the dependencies between pixels and between bitplanes are considered,the data access times and coding complexity are far lower than that of the current algorithms.Moreover,the algorithm is an embedded coding algorithm,the compression ratio could be precisely controlled by truncating the bit stream,and the progressive transmission of the code stream could be supported.The experimental data show that the complexity of the algorithm is significantly reduced,and the compression performance is slightly higher as compared with that of the image compression algorithm recommended by the CCSDS.Meanwhile,the algorithm also supports bit plane independent parallel coding and improves compression speeds.The algorithm has met the space application requirements for the high-speeds,high performance,low complexity and the low power.

The three-axis tracking structure of vehicular opto-electronic equipment with a latitude axis range of ±20° can not track all secondary planets in the half-airspace.So,this paper explores the principle of satellitic tracking,derives the relationship formulas between three axes and gives a tracking tactic arithmetic for the STTA satellite by a simulation.When a secondary planet with a tracking elevation above 70° is tracked,the azimuth-position horizon tracking mode is adopted.It not only uses the superiority of the horizon gimbal mode with a lower tracking error,but also conquers the altazimuth gimbal with tracking dead zone.When a secondary planet with a tracking elevation bellow 70°is tracked,the azimuth gimbal and following up mode is adopted.It combines the superiority of the horizon gimbal and altazimuth gimbal and receives the better effect.This arithmetic not only has solved three-axis turntable vehicular space but also has ensured the secondary planet in an assuring range and can capture all secondary planets in the half-airspace.The experimentation is designed,which verifies that the tracking tactic arithmetic is effective and feasible.

A multilevel threshold image segmentation method based on hybrid Particle Swarm Optimization(PSO) and Gravitation Search Algorithm(GSA) was proposed to solve the weakness that a single algorithm in image segmentation has a lower local searching ability.A strategy of generalized opposition-based learning in image segmentation was proposed to improve the population diversity and to strengthen the global searching ability in optimizing processing.The normal mutation strategy on the best particle was conducted to extend the searching space and to avoid the premature convergence of the algorithm.Then,the multilevel threshold image segmentation method of hybrid PSOGSA with generalized opposition-based learning was implemented.Finally,complex image segmentation experiments were processed by proposed method and the results were compared with those of multilevel threshold segmentation methods of GSA and Firefly Algorithm(FA).Experimental results show the proposed method possesses a higher accuracy in multilevel threshold segmentation and the standard deviation of best objective values in continuous operation has decreased by up to 90%.Therefore,the image segmentation method of multilevel threshold using the hybrid PSOGSA with generalized opposition-based learning can be accurately and stably used in multilevel threshold image segmentation.

For the mismatching problem in computer vision,a fast local stereo matching algorithm based on seed pixel propagation was proposed to further improve the efficiency of matching algorithm.Firstly,the edge of an image was extracted using Canny operator in order to overcome the adverse influence of a fixed window on stereo matching by combining with the edge information to construct a dynamic matching window.Then,the AD-Census combined matching costs was used to realize the cost aggregation on the dynamic window,the initial disparity map was obtained by WTA search strategy and the disparity was filtrated to get seed pixels.Furthermore,the color difference between pixels was used to propagate the disparity of seed pixels to around unseeded pixels.Finally,the region voting and local rectification were adopted to refine the disparity and to get the accuracy dense disparity map.Experimental results show that the algorithm provides high-quality disparity map on Middlebury data set,the computing time is accelerated by 1.8 times as compared with that of newer local matching algorithms at present.It meets the demands of actual applications for accuracy and speeds.

The corresponding technologies for sharing information and 3D interaction by Web3D were described briefly.An efficient scene management scheme for real-time visualization of a large-scale underground scene was proposed to meet its demands for webpage visualization.Firstly,the raw data from the underground scene were preprocessed in lightweight,and a shell structure-aware scene analysis algorithm was employed for constructing a scene management structure.Then,some strategies were put forward according to the characteristics of the underground scene data,and those are a SOI-ExteriorShell strategy based on Sector Of Interest(SOI) management for outdoor scenes and a Portal-InteriorShell strategy supporting progressive loading for indoor ones.With the switch between indoor and outdoor scenes,the method dynamically chooses the corresponding strategy and makes it possible to roam in the large-scale underground scene online.From the final experiment,it concludes that the proposed method efficiently culls unnecessary scenes in a greatly large extent and is capable of meeting the requirements for real-time visualization of the large-scale underground scene over Internet.As the webpage has an advantage of cross-platform,the system supports users to roam and control the large-scale underground scene under cross-platform.

A three Field of View(FOV) celestial positioning and orientation system was established to achieve high-precision position and orientation.The concept of the three FOV celestial positioning and orientation was described,and the working principles of the system were introduced.A celestial positioning and orientation algorithm based on the minimum loss function was proposed to calculate the geographic position and the azimuth angle information of a carrier simultaneously.According to the structure characteristics of the three FOV system and traditional single FOV system,the advantages of the former on positioning and orientation performance were analyzed theoretically.Finally,the simulation analysis was performed on the effects of the dip angle errors of a carrier platform and the single star measuring errors of a star sensor on the celestial positioning and orientation,and a field experiment was executed with a prototype.Experimental results indicate that the positioning accuracy is 151.624 0 m,the orientation accuracy is 4.630 4″ and the positioning and orientation result is stable.These results satisfy the requirements of the high-precision celestial positioning and orientation.