A calibration model for determining the cotton content in cotton-terylene textile precisely was established.The near infrared spectra of 50 cotton-terylene textile samples were collected using self-designed accessory,and Savitsky-Goaly filter smoothing,first order derivative and second order derivative were used to pretreat the spectra.Calibration models for cotton content were established with Partial Least Square(PLS).The experimental results indicate that Savitsky-Goaly filter smoothing spectral treatments can not affect the performance of the model in this case,but NIR technique can analyze the cotton content in the textile precisely.The Root Mean Square Error of Calibration(RMSEC) and Root Mean Square Error of Prediction(RMSEP) are 0.022 and 0.018 respectively,and the error of analysis is restricted in ±0.05.In addition,several key aspects of this application were expressed.

Several effect factors on the radiometric calibration results of space ultraviolet remote sensing instruments in orbit were studied,for the diffuse reflection ratio of a diffuser was changed in space environment.A device to study vacuum ultraviolet radiation characteristics of diffuser by simulating space ultraviolet radiation environment was build up,and the vacuum ultraviolet radiation characteristics of Al+MgF2 diffuser in space ultraviolet remote sensing instrument were researched.The experimental results show that vacuum ultraviolet radiation accelerates the degradation of diffuser reflection ratio at 160～300 nm;the degradation value increases with the increment of radiation time;the degradation varies linearly at 160～300 nm and the degradation rate differs with the wavelengths.Finally,Factors that might cause degradation of diffuse reflection ratio were analyzed primarily.

A design of spectral tunable Light Emitting Diode(LED) light source composed of an integrating sphere and a large number of LEDs was described.The source was designed to produce different spectral distributions in the visible region,and it could simulate the spectral distributions for various light sources.A series of simulations were conducted to predict the performance of spectral distribution of the designed tunable source and a power control box in the source was designed to control every LED module accurately.Experimental results show that the uniformity of the source is 0.53%,and the performance of the angle is 0.77% in ±10°.This new type of source can be used as a transfer standard for radiometric application.

In order to get enough information,and to avoid the big chromatic aberration of wide spectrum and the complexity of optical system,a harmonic diffractive/refractive optical system was established by making the best use of science value of terahertz.A 14～50 μm terahertz wave was integrated into multi-band imaging system based on the special large dispersion capability of harmonic diffractive element,and the longitudinal aberration was simultaneously limited to less than 0.75 mm in the five harmonic wave bands (15.8～16.2 μm,18.5～20 μm,23～25 μm,30.5～33.5 μm and 46～50 μm).In each harmonic wave band,the magnification changed as a function of wavelength,which created image registration error.To compensate this shortcoming,a zoom optical system was designed by binary optical component.The design results show that the image height keeps 6.74 mm in every harmonic band and the zoom optical system can realize aberration compensation action.In the five bands,each optical transfer function approaches to the diffraction limit in 10 lp/mm.These results indicate that the system can meet the requirements for portability,minitype and easy fabrication.

In order to investigate the Atomic Force Microscope(AFM) based nanoindentation process of monocrystalline copper film,a three-dimensional molecular dynamic simulation model of nanoindentation process was established.The Morse potential was used to compute both the effect of interactions between the specimen atoms,and between specimen atoms and indenter atoms.Nanoindentation processes were conducted to evaluate the indentation depths (0,0.361,0.722,1.083 nm) on the indenter stress and variations of system potential energies.The results show that the plastic deformation via amorphous transformation is caused by the mechanism of nanoindentation of monocrystalline copper film.With the increase of indentation depth,both of the variations of system potential energies (range of -83 900～-83 400 eV at the maximum indentation depth) and the force (range of -0.3～70 nN at the maximum indentation depth) increase,which shows a strong size effect.

In order to improve the transmission property of Frequency Selective Surface (FSS) structure,a novel element FSS containing an improved cross element was presented.By applying modal matching approach,the novel element FSS was compared with the traditional cross element FSS theoretically.The influence of the changing angles of TE incidence and the polarizations of large angle incident waves on center frequency was researched.With coating technology and lithography,FSS samples with improved elements were made.The tests were carried out in a microwave darkroom.The measured curve shows a good agreement with the emulated curve.The results show that the traditional cross element FSS can not have angle independence on TE incident waves or polarization independence on large angle incidence,the drift of resonant frequency is 300 MHz for 0～45°TE incidence,and 800 MHz for different polarizations of 45° incident wave;In modified structure,the resonant frequency of FSS remains independent of incident angles,the drift of resonant frequency is only 100 MHz for 0～45° incident wave,also,the resonant frequency maintains the independence for different polarizations.

As a very important Resolution Enhancement Technology (RETs),Off-axis Illumination (OAI) is widely applied to optical projection lithography system.Application of Diffractive Optical Element(DOE) to OAI not only can cotrol precisely the flexible illumination shape and the intensity profile but also can retain a higher efficiency of light source.In this paper,the four kinds of DOEs with 8 phase levels were designed by using the step-iterative algorithm based Fourier transfer,and the four elements could realize dipole,quadrupole,annular and Bulls-Eye illuminations respectively.The simulation results show that the efficiencies of the light sources are all better than 80% and the RootMean-Squares(RMSs) of intensity profiles are all smaller than 7% as compared with that of the ideal one.

An optical design method for large aperture zoom optical system was introduced.The optical system was divided into two segments called front optical system and back optical system.The front optical system used a reflective system to meet the request of large aperture and the other one used a converse zoom objective.The two segments were assembled at the first imaging of the optical system to ensure the imaging quality of the optical system through optimizing the converse zoom objective of back optical system.This method is proved feasible from a design example,it also shows that designed system is simple and compact and easy to fucus for zoom lens with large aperture.

The spin drive principle of superconducting rotor and a fiber optic sensor measurement system used in spinning superconducting rotor instrument were introduced.The measurement system includes a displacement fiber optic sensor,a speed fiber optic sensor,a motor control fiber optic sensor and signal readout patterns.It can not only gauge suspension micro-displacement and the rotative velocity of rotor,but also can generate some necessary motor control signals to drive rotor.The experimental results of the suspension and rotation of rotor at liquid helium temperature (4.2 k) show that the measurement resolution of suspension micro-displacement of superconducting spherical rotor is 10 μm and the rotor rotary speed is 1 365 r/min,which can give some useful references for the further application of fiber optic sensor measurement system to monitoring operating position of a rotor accurately.

In order to realize one-to-many and many-to-many communications for optical waveguide matrix switch,a new type of optical waveguide matrix switch was designed.Two switch units were defined on analysis of the basic structure of Mach-Zehnder Interferometer (MZI).Then,based on this two units,the new structures of 2×2 and 4×4 optical matrix switches were proposed to realize the multiport interconnection of 1∶k(k>1).The influences of the intersection angles among waveguide links on the intersection-induced optical loss of system were studied in Banyan network and the total insertion losses of system were discussed after the performance simulation and the optimization of MZI construction.Finally,SiO2-based MZI units,2×2 and 4×4 optical matrix switches were fabricated based on Planar Lightwave Circuit (PLC) technology.The experimental results indicate that the insertion losses of 2×2 optical matrix switch and 4×4 optical matrix switch are 2.25 dB and 4.3 dB,respectively,and the response time is less than 1 ms.It concludes that this type of optical switch can primely fulfill the multiport switch function.

In the design of cubic phase plate testing system by taking Computer Generated Hologram(CGH) as a null lens,two very important principles are the wavefront aberration of cubic phase in propagation and the separation of diffraction orders.The cubic phase introduced higher order aberration in propagates was presented,and an expression for the aberration of cubic phase in propagating was deduced in detail.From the expression,it was shown that the high order aberration increases as the propagation distance l increase.The theoretical foundation for the diffraction order separation of testing wavefront diffracted by the CGH was discussed.To prove the theories,a cubic phase plate testing system was designed for an example.By introducing the 4th and the 5th order items,the wavefront aberration reduced from 0.7 λ to 0.007 λ.The results coincide with the theoretical formula well.

The multilevel diffraction spectrum of target image on the filtering plane produced by the periodic structure of Space Light Modulator(SLM) in Vander Luget Correlator(VLC) was obtained.In order to increase output correlation peak value,matched filters can be loaded at the positions of different diffraction spectra on the filtering SLM at the same time to perform matched filtering of multilevel diffraction spectra.Theoretical analysis results indicate the correlation spots from different diffraction spectrum outputs are at the same position of the output plane,and the correlation peak value is improved with coherent superposition of multilevel correlation spots.The experimental results show that the mean output correlation peak value by performing matched filtering for multilevel diffraction spectra of target image has increased about 32% than that of zerolevel spectrum.The output correlation peak value can be effectively increased using this method.

In order to measure accurately the refractive index of optical glass to improve the imaging quality of optical systems,several measuring methods of refractive index for optical glass were analyzed and both foreign and domestic development situations for optical glass measurement were introduced.A new method to calculate refractive index by measuring the three least deflection angles of three vertex angles of a prism was presented.Proposed new method made full use of the orientation dominance of complementary method or three-image method improve the accuracy of refractive index measurement,and it was characteriszed by the accuracy improvement of refractive index measurement with refractive index increasing.The formula of new method was deduced,the measurement accuracy was analyzed in the theory.Result indicates that measurement accuracy has improved more than twice as compare with that of traditional least deflection angle method,which can meet the requirement of high accuracy measurement of refractive index.

In order to solve the thermal effect problem of diode bar side-pumped laser slab,a temperature modeling of laser slab according to the practical situation was established based on analysing on the temperature field and thermal distortion field of diode bar side-pumped laser slab and discussing on its working characteristics.A novel solution of the Possion equation was established and the general analytical solutions of temperature field and thermal distortion field of laser slab were obtained.Then,by taking the Nd∶YAG slab as a model,the distributions of temperature field and thermal distortion field were analyzed.And the temperature fields of Nd:YAG slab under different pump powers and coupled radii were quantitative studied by considering on design requirements of all-solid-state lasers.Computational results indicate that when the YAG doped with a mass percent of 1.0% of Nd-ion is side-pumped by a diode bar with output power of 30 W,the Gaussian spot radius coupled on the side-face of laser slab is 150 μm,and the slab can get a maximum temperature rise of 102.3 ℃,and the maximum thermal distortions of 1.54 μm and 2.66 μm on the side-face and the end-face,respectively.This analytical solution of temperature field can improve the low precision of the numerical analysis method in research of diode laser side-pumped laser slab interior temperature field,and also can be used to analyze other thermal problems in laser systems.

To obtain the distortion of three-mirror off-axis,the calibration method and procedure of a system are presented,the principle and the composion of calibration system are also introduced.The distortion of three-mirror off-axi is analyzed,then a mathematical model for distortion calibration is established by means of least square regress method and the image distortion of a three-mirror off-axis is calibrated by combining a high accuracy turn table and a long focal length collimator.The results show that the calibration accuracy of absolute distortion is less than 2 μm(1σ),and the calibration accuracy of relative distortion is less than a 1×10-4(1σ),which shows that proposed method can meet the request of high accuracy calibration of the distortion for three-mirror off-axis.It is valuable for the practical application.

A high-precision optical angular measurement method is proposed to measure the torsion angle based on the Moiré fringe produced by double diffraction grating interference.In order to validate the validity of measurement equipment by Moiré fringe,the schematic design and experimental analysis are carried out.The torsional flexibility of a three-dimensional object is simulated by collimator simulation equipment adjusted by a fine-tuning mechanical structure.The measurement experiments are carried out on the independent foundation platform.By comparing different design proposals with experiments,a scheme of CCD target surface installed in the image surface of parallel light is selected to use in this measurement.In this scheme,the image processing technology of filtering thinning is used to obtain the stripe width by treating the collected Moiré fringe,and the torsional flexibility value is calculated by the mathematical model and the changes of stripes width.The experimental results show that the clearer Moiré fringe image can be gotten in the scheme when the collimator is circumgyrated by fine-tuning institution in the field of view of ±7′.And the measuring accuracy of torsion angle is 4.3″(3σ) by the algorithms process when the Moiré fringe width is 1 615~1 712 μm.This method meets the measurement requirements of high-accuracy of torsion angle between equipments,and it lays the foundation to enhance the photoelectric precision of measurement equipment.

An extraction algorithm for missile bullet multiple targets is researched.By OSTU method,the numeral image is changed into binary image,and the center position and the target area are extracted separately.At the same time,the target area is marked and the threshold of area is enacted.According to target area,the conglutination and obstruction are judged.Then,in term of the variety of grey histogram of conglutination region in wave peak and wave valley,the targets are separated to obtain the grey average of target,and the middle axes of targets are acquired by adopting Hough transforming and proximating.Finally,the obliquity angles of targets can calculated.In course of matching,searching region of target matching is forecasted by using Kalman filter;the data association of serial images and extraction of missile bullet multiple targets are accomplished by using improved eigenfunction after obtaining center position of target,target area,grey average of target and obliquity angles of target.The experimental results show that the right ratio of extraction target reaches up to 90%,which shows that the article uses a correct mathematical model and a reasonable algorithm.

In order to get the video image with large visual field in range instrumentation,a system of auto-stitching multi-lens image with large visual field is established and its applied algorithms,such as image matching,marking lapped area,seamless stitching and so on,are investigated.The theories of wavelet transformation and wavelet-packet are presented.An image-matching algorithm based on wavelet-transformation by matching wavelet parameters of image is analyzed.Then,the comparing and rotating algorithm to mark the lapped area is analyzed,in which the only lapped area is marked after sub-lapped areas are matched and rotated.Finally,the image seamless stitching algorithm based on wavelet-packet transformation is analyzed.After image wavelet-packet transformation,the wavelet parameters are merged by frequency and then the image is reconstructed using the result.Experimental results indicate that the system gets an image with 3.3°×1.76° large visual field by stitching four images with 1.1°×0.88° visual field,the stitched image is smooth and seamless ,the speed of the system can reach up to 10 frames/s.These results show that proposed stitching method can satisfy the requirements for range instrumentation in getting image with large visual field.

In order to satisfy the requirement of real-time tracing for photoelectric theodolite with multi imaging systems and to guarantee tracing precision and reliability,a new servo-control system according to Multiple Instruction Multiple Data Stream(MIMD) structure was proposed.The predictive filtering and data fusion of theodolite was derived theoretically.The results show that solution of data fusion needs a vast amount of numerical calculations.In order to satisfy the calculation requirement,a special parallel calculation system with three arithmetic units,two DSPs and a single FPGA was developed.The time outgoing of real-time calculation for each calculation unit was analysed.The simulation results show that the system can achieve 1.25 ms operation time in real-time for the theodolite with three imaging systems,while the CCD sampling frequency is 50 Hz and sampling frequency of photoelectric encoder is 800 Hz.

The turbulence and overshot come from switching tracking mode in theodolite system are investigated.A math model of the system switching is established and the reasons for these problems are figured out in theory.In order to improve the characteristics of transient response,an initial value compensation method based on compensating the difference outputs between current controller and former controller is proposed and compensated math model and response for this system are given.Simulation results indicate that the turbulence of miss-distance is restrained within 0.003°,which improves the dynamic process of the system and suppresses the turbulence in switching track mode.

The dimension and configuration of space camera is mainly determined by the optical system of the camera.for certain optical design specifications,it is necessary for realizing miniaturization,lightening and high reliability of camera to study several optical system constructions.This paper describes the high resolution visible space camera in sun synchronous orbit using TDI CCD push-bloom imaging method.In assuming the orbit height of 500 km,the ground pixel resolution of 0.5 m,six kinds of optical system configurations are analysed using the CODE V optical design software,the different F numbers and Fields of View(FOVs) are obtained,and useful optical design data are presented.The conclusions reported here suggest that the FOV should be determined by different widths of the ground covered,then the optical system configurations are chosen by need of FOV and small dimension.

In order to study the structure stability of fine support components made of Carbon Fiber Reinforced Polymer (CFRP) in a large-aperture space optical remote sensor,a CFRP joint cylinder between primary mirror and second mirror was designed and manufactured.The maximum deflection was calculated in the light of the angle change between primary mirror and second mirror,and the mechanical model of the joint cylinder was established according to actual load.The axial elastic modulus based on the model was calculated and the an appropriate layer sequence CFRP was determined by composite laminate theory.Then,the angle between the two mirrors and the modal distribution of support structure were calculated based on software ANSYS.Finally,the structure stability was validated by the crescent mechanic test and optical measurement method.The results show that the angle displacement between primary mirror and second mirror is less than 10″,the first-order natural frequency of CFRP support component is greater than 75 Hz.CFRP support has better structure stability,which satisfies the requirement of general technologic index.

Quantitative Fault Tree Analysis (FTA) is very effective in analyzing the reliability and safety of space camera software system.Aiming at the difficulty to get information of system faults and construct of fault tree,a method establishing software fault tree based on Rough set is put forward.Because software failure cause is anfractuous and available data are hard to get,a modelling method for bottom event is proposed based on Vague set to calculate the relative significance of bottom event and the occurrence probability of top event.Then,analyzed result from the model is used to guide design of software reliability.Experimental results show that the new method of software FTA can help designer improve system reliability by fault tolerance and error design.The results also show that the new method makes software quantitative analysis possible and optimizes the precision of software measurement.

In order to realize the thermal control of high-power Focal Plane Apparatus (FPA),the thermal design of FPA was studied according to the structure characteristics of the FPA by simulation and experiment.The main requirements of the thermal design of high-power FPA were introduced and the feature of thermal design of a focal plane assembly was analyzed.Then,the thermal performance was simulated by means of code TMG.A thermal test was carried out and the temperature fit curve of FPA according to the thermal test was given.Finally,the method for choosing the thermal control mode rationally was put forward according to thermal design example.The results show that the temperature of 50 W high-power FPA can be controlled to lower than 35℃ when it works for 2 min continuously in 12℃ cool source.It can meet the design requirements of FPA.

ICL7667 was used as a power MOSFET driver in stepper motor drive system in order to increase switching speed of the power MOSFET and to realize high-frequency chopping control for stepper motor.The gate capacitance and switching time of the power MOSFET were studied.The results show that the charge and discharge processes of gate capacitance affecte the switching speed of power MOSFET.So a method increasing the switching speed of the power MOSFET was introduced.Finally,ICL7667 was used as a power MOSFET driver to achieve a high-frequency chopping control for stepper motor.Simulation and test results indicate that the chopping frequency by using ICL7667 can reach up to 200 kHz when the power MOSFET is still in cut-off or deep saturation,which has increased by 10 times as compared with 20 kHz by using voltage division with resistor.In proposed system,stepper motor can run correctly under control of high-speed chopping signal.

In order to realize high precision image motion compensation,the requirements of space camera system was put forward by analyzing the effect of aerocraft attitude on image motion compensation.The image motion match characteristics demaned by Modulation Transform Function(MTF) of camera was analysed to determine the permitted errors of image motion matching.Then,the Monto-Carlo method (statistic distribution method) was used to analyse and calculate the errors of image motion velocity.Finally,the attitude accuracy suitable for image motion compensation was abtained.The conclusions drawn by calculation suggest that the attitude accuracy should be higher than 0.1° and the attitude stability accuracy higher than 0.005°/s,which can meet the requirements of errors of image motion matching of 96 TDI-CCD integration progression.The method is simple,easy to implement and suitable for the study of image motion compensation of space camera system.

The laminated photoresist sacrificial layer technology and residual stress control in micromirror fabrication were investigated.Pollution problems in electroplating related to the photoresist sacrificial layer were discussed and their solutions were proposed.Through experiments,a new fabrication process is developed to solve the problem that the solvent in upper photoresist penetrates the electroplating base metal layers and dissolves the sacrificial layer to damage middle layer;the thicknesses of two kinds of metal films with different stress states in evaporating and electroplating processes are controlled to remove the residual stress on the surface of a micromirror.Employing these new technologies,the perfect flat micromirror with the size of 620 μm×500 μm×2 μm,and air gap height of 12 μm is fabricated successfully.

In order to eliminate the deformation and improve transmission precision,the simulation method for deformation of flexible wheel is researched under actual situation.Under the condition of the load torque of great speed ratio frictional transmission in 2 N·m and the transmission ratio in 200,the flexible wheel is modeled with elastic mechanics theory and finite element method,and its different amounts of deformation caused by different loads are analyzed by ANSYS software.A device for testing deformation of flexible wheel is designed to use for an actual measurement and the angle amounts of deformation by different loads are tested with a 0.2″ electronic leveler.The tested results indicate that the difference between the theoretical values and pratical one is about 1.85″ when the load is 0.88 N·m,which shows that the experimental results are coincident with that analysed by elasticity and FEM.

On the basis of the six-wafer combustor used in a micro-gas turbine engine developed by Massachusetts Institute of Technology(MIT),a two-dimensional Computational Fluid Dynamics(CFD) simulation was employed in studying the effect of hydrogen/air ratio on the combustion performance in a micro combustor when the mixture mass flow rate was fixed.The CFD modeling includes the hydrogen/air flow path,combustion chamber as well as the solid walls of the micro-combustor,and the simulation analysis involves in the flow mechanics,heat transfer and the numerous chemical reactions occuring in the micro-combustor.The results show that the flame will be quenched finally in the chamber when the equivalence ratio of fuel/air mixture is 0.4 and the combustion is more stable when the equivalence ratio of fuel/air mixture is 0.5 or 0.6;the flame front will propagate to the upstream of the fuel/air mixture flow,burning in the recirculation jacket when the equivalence ratio is increased to 0.7.It comes to a conclusion that the present numerical simulation is helpful for the design and improvement of the micro-combustor.

A new non-IC method for fabricating micropipettes was presented to improve traditional micropipette fabrication from pulling of glass capillary to solve problems such as easily brittle fracture,hard to control length of microchannel and low efficiency of micro-jetting.By choosing the round cross section with lower flow resistance as the nozzle shape and embedding the multi-microchannels tightly into the plastic pipe by employing the rheologic flowing of plastic and the different shrinkage ratios of two materials in cooling,a conical pipe connecting microchannels and plastic pipe were formed by capillary and corrosion action.Meanwhile,the length of micronozzle was reduced.fabricated conical pipe characteristics by low cost,simple manipulation and safe process.The micropipettes with 4 and 10 micronozzles in inner diameter of 50 μm,and the length of 2.5 mm for micronozzle were fabricated,and the length of the conical pipes was 750 μm.The experiments of micro-jetting of aqueous liquid into oil phase and gaseous phase were carried out by employing digitalization of microfluid technology with the micropipettes and the microarray and micro-droplets with diameter of 80 μm were prepared.The experiments show that the micropipettes can well work at digitalization of microfluids technology.

For correcting the erroneous dropping of external stores on dropping mechanism of aeronautical weapons,a finite element technique was adopted to analyze on the hook,sector rocker and sector wheel to find out the reasons for erroneus dropping,and an improvement method was put forward without changing the structure of the dropping device.A mechanism applicable in micro space was designed with computer-aided 3-dimension motion analysis and interferometry.By using computer-aided statics,dynamics,thermo-elasticity and stability engineering analysis(CAE) techniques, the structural stability of the mechanism was studied in aspects of dropping sequence,energy requirements,rigidity and the intensity of stop. The results of calculation,experiment and aerial embarkation flight show that the theoretical power value consumed by the stop is 10 W,and measured value is 14 W;the measured value of tripping voltage is 7 V,and the theoretical value of the time sequence is 0.003 8 s,these values are much less than those of the dropping device itself.Experimental results show that improved mechanism acts safely and reliably,and avoids mutual interference between all moving accessories of the main body,which provides evidence for engineering application.

A new ship distortion measurement method based on image network transmitting technology was presented and the theory and the actual application of the new method were validated.The distortion measurement system of the ship was introduced,the characteristics of aggregative processing system were compared with that of distributed processing system.The comparison indicates that proposed new system has the technology advantage.The time characteristic of the new system was analyzed and system technology feasibility was demonstrated.Experimental results show that the system can expend 15 ms to complete an image capturing and processing for a measuring sensor with 16 cannels,which can meet the requirement for data capturing of the measuring system for a ship.

A new uncertainty estimation method was researched based on Monte Carlo evaluation,for some uncertainties of large-scale measurement could not be analyzed by conventional methods,especially for special fitting task.In proposed estimation,the simulated sample was obtained by simulating each measuring error source randomly and denoted as discrete point-clouds by computer vision,so as the uncertainty of given measuring object could be evaluated.By taking analyzing large-scale circular section part by laser tracker for example,the optimized measurement concepts including point symmetry,equal distribution and radius constraint were given.Finally,the optimized evaluation method was used in measuring practical tunnel components by laser tracker,results show that the uncertainty is decreased to 0.032 6 mm after radius constraint optimization,which is priority to average fitting uncertainty of circle center of 2.5525 mm by traditional method.It is proved that Monte Carlo evaluation and discrete point-cloud representation can evaluate accurately and intuitively the uncertainty for large-scale object and the optimum sampling strategy can improve the measuring precision.

The state-of-art of the related research for radial magnetic couplings was reviewed.A practical mathematical model and a novel criterion were set up.And then,improved Equivalent Magnetic Charge(EMC) method was compared with original one,Current Sheet Model(CSM) method and 3D FEA method in efficiency and accuracy.Finally,Design of Experiments(DOE) was introduced and an effective and practical optimizing process was proposed.The results show that the accuracy of improved EMC is increased by about 5% and the efficiency is increased by about 55% compared as that of the original EMC method.The error of the CSM method is big,though the efficiency of CSM is much higher.For the 3D FEA method,the circumstance is contrary.The proper initial values can be obtained only by using nine simulation models with the DOE method,and multiple sets of optimizing cases were obtained easily through standard optimization methods.The results show that proposed optimizing method can satisfy the requirements of practicability,higher precision as well as strong stabilization.

In order to provide high quality information security service in public network,a new scheme is developed for constructing a secure Virtual Private Network(VPN).In this scheme,security protocols are separated from operating system and integrated into the network equipment—safe Ethernet card.When a program makes use of network equipments,the protocols cannot be bypassed.So the scheme can be used in security communication and can prevent active attack.The hardware platform and inner software structure of the Ethernet card are introduced,and the multiple access manners of the VPN are discussed.A method accessing ADSL in VPN based on PPPoE in the card is presented,which is validated to achieve the expected purpose.

In order to improve the automatic light adjustment for traditional CCD camera system in engineering,a new full-automatic light adjustment method for CCD camera system was presented.In this method,light was adjusted by combining external trigger electronic shutter mainly and iris diaphragm assistantly.For obtaining a moderate image illumination,the electronic shutter time of CCD camera was adjusted by external trigger and the aperture of iris diaphragm was adjusted by motor controlled by single-chip.Feedback control quantity was obtained from the mean level of target region of image,so that the full-automatic light adjustment was implemented.Matlab simulation results show that histogram related to image of new light adjustment system is wide and uniform,and the peak value of its power spectrum is more than 7.5 dB.The image of the new light adjustment system is clean and high-contrast,which shows new system can satisfy requirements of the optimal full-automatic light adjustment for modern CCD camera system.

Based on original Nonnegativity and Support constraint Recursive Inverse Filtering(NAS-RIF) algorithm,an improved blind image restoration algorithm was proposed.In order to achieve the trade-off between the fidelity of observed image and the smoothness of restored image and to prevent noise amplification,a new cost function of the NAS-RIF algorithm was introduced by adding space-adaptive terms and a regularization term.The space-adaptive terms could be calculated through the local properties of the observed image and the the noise variance.A algorithm using conjugate-gradient routine to calculate the optimal result was proposed to estimate the noise variance in unknown transcendental condition.The improved algorithm and original algorithm were both used to restore three different degraded images.The experimental results show that the ΔSNRs by proposed algorithm are increased by 0.207 3 dB,1.023 9 dB,2.862 8 dB as compared with those of original NAS-RIF algorithm.It demonstrates that the improved algorithm is more efficient.

3D image merging is a key technique in large scale free-form surface measurement.Based on image-control-point-restraint theory,a new 3D image merging method is presented.In the method,a pseudo-random space code is firstly projected on a large object surface,and the images of the object are taken from different angles of view.Through matching the interest points on the overlapping region,the coordinate transformation matrix is obtained and 3D measurement of large-scale free-form surface can be realized.The experimental results show that this new image merging method by space code projection can measure large-scale 3D shape and the relative error of merging data is less than 0.8%.

Based on the invariance of cross-ratio and the collinear property of all points for one dimensional target,a global calibration method of multi-vision sensor system is proposed.The global coordinate frame is constructed based on the coordinate frame of one of the vision sensors,which is called the base vision sensor.The one dimensional target is positioned arbitrarily for at least twice in front of both the base sensor and the sensor to be calibrated.For each vision sensor, the image coordinates of the target feature points out of the view field are computed utilizing the image coordinates of at least three feature points captured by the vision sensor according to the invariance of cross-ratio.A transformation matrix from the coordinate frame of the sensors to be calibrated to that of the base sensor is solved by considering the distance restraint between target points and optimized solution is obtained by non-linear optimization method.The global calibration of multi-vision sensor system is realized by pair-wise calibration between the base vision sensor and each of the vision sensors to be calibrated.Experiment results show that proposed method can do calibration without any high-accuracy 3D measuring equipment,it is simple,flexible and applicable in various situations.Calibration result shows that the error of global calibration method is 0.041 mm.

For achieving high precision measurement of linear profile for micro-parts,an evaluation algorithm of linear profile based on discrete points is proposed according to the imaging characteristics.Firstly,an edge detector is used to obtain the edge of the micro-parts.Then,a series of points with tiny interval can be calculated by the expressions of designed profile and a system coordinate is build for corresponding the points of actual profile and the points of designed profile.Finally,the minimum distance between every point of actual profile and the point of designed profile is taken as the linear profile error of the point.The experimental results show that the error is less than 2 pixel,so the proposed algorithm can significantly improve the precision and efficiency in the measurement of linear profile.

In order to improve the accuracy of optical tracker,the macro pixel method is used for estimating initial target region.A term,valid pixel ratio,is put forward and then is applied to analyze the effects of noise and asymmetry on the location for initial target region.Finally,the most macro pixels and the restricting operation way with high-precision and strong anti-noise ability are obtained.For the unsymmetry target of 4 pixel×4 pixel in 128 pixel×128 pixel spot image,the most macro pixel is 36 pixels and target macro pixel is enlarged by 2 pixel.The value of r is 1 when SNR is 5 dB.Dynamic picture test shows that the method has the processing speed of 18～20 frame/s.

Several kinds of experiments by proposed methods is carried out based on combining interpolation and wavelet image fusion to improve the resolution of ultrasonic images,especially for transverse resolution.The experimental results show that it is feasible for improving the resolution of ultrasound image to determine image by comparing the region energy.The wavelet decomposition is used to decompose the interpolated images to the low frequency part and the high frequency part,then,the low frequency part is processed with the method of average,and the high frequency part with the fusion method of the largest region energy,which obtains better effect on improving the resolution of ultrasonic images.

In order to realize real-time rendering for medical images on PCs,a scheme combining multi factors for assigning optical attribute to resampling points is defined,and then a novel rendering algorithm for medical volumetric data is presented.The volumetric data are classified into the foreground voxels and background voxels,and the foreground voxels are resampled using Layer of Detail(LOD) technique.Then,the optical attributes of resampling points are determined by the defined method,which is reasonably associated with the distances between object and viewpoint,as well as object and light source.Finally,the background voxels are displayed by the accelerated method based on space leaping resampling.The experimental results indicate the presented algorithm can reach up to 2.5 frame/s clearly on PCs for 512×512×482×2 Byte volumetric data,when it reduced to 2/3 times of the original size.It comes to the conclusion that the interactive volume rendering can be implemented for most medical volume data on PCs.Moreover,tissues or organs can be displayed clearly,which is more coincident with the human vision.

Aiming at problems of both the contour initialization and the robustness in traditional segmentation methods for Intravascular Ultrasound(IVUS) images,a novel scheme is proposed to segment IVUS images of plaques based on the active contour model and the Contourlet multiresolution analysis.With the contourlet transform,the original image is decomposed into lowpass components and bandpass directional subbands.The template matching is adopted in lowpass components to yield the initial contours of lumen border and media-adventitia border.The anisotropic diffusion is then utilized in bandpass directional subbands to suppress the noise as well as preserve vascular boundaries,and the contour evolution in the boundary vector field is used to obtain final contours.The method is evaluated via 100 simulated images and 120 real images,and results demonstrate that the mean distance error and the percentage of area differences have increased by 3.04 pixels and 6.30%,respectively,as compared with those of the traditional active contour model.These results show that the proposed method can automatically and accurately extract two vascular borders.