The Optical Low Coherence Reflectometry (OLCR) is proposed to solve a problem that the reflective spectrum of a Fiber Bragg Grating (FBG) can be out of a shape under non-uniform strain loading. Based on a Michelson interferometer,an OLCR system is set to measure the pulse response of the FBG,and the time domain pulse response of FBG is converted into the frequency domain reflection response by Fourier transform. Then the spatial response of FBG relevant to Bragg wavelength is reconstructed with a lay peeling technology. Thus, the non-uniform strain distribution is calculated from the sensing model of FBG. With an effective system, the OLCR is illustrated in detail. An experiment of composite delamination in modeⅠis conducted, and the non-uniform strain distribution is obtained with reliability. The axial measurement resolution in the FBG is 13.2 mm, and the scanning precision of the system reaches 100 nm. The OLCR system demonstrates an excellent performance in demodulating the FBG non-uniform strain sensing, which shows that the system has a promising application prospect.

In order to achieve the focusing in real time and to obtain the high writing resolution and diffraction efficiency in the exposure process, a new maskless lithography based on a continuous-relief harmonic diffractive microlens (DMs) array is proposed. The lithography takes the continuous-relief harmonic diffractive microlens array as an objective array of the maskless lithography to integrate the defocus-detecting array and the writing array by taking both the writing resolution and diffraction efficiency into consideration, and to design the array with a deep relief to make the array fabrication easy. To verify its validity,the continuous-relief harmonic diffractive microlens array with F/7.5 and a design wavelength of 441.6 nm is designed, and fabricated after analysis on the characteristics of maskless lithography. Experimental results indicate that the developed array can be used to synchronously focus the writing laser and the autofocusing laser into the same spots, and can achieve a diffraction efficiency over 70% for both writing wavelength and defocus-detecting wavelength.

To characterize the size distribution of aerosol particles, a measuring simultaneously method for aerodynamic diameters and optic diameters of the aerosol particles is studied, and then the classifying count principle is described. Based on large-scale programmable logic chips and dual-port high-speed large-capacity memory chips, a high-speed and large-capacity classifiying count storage for aerosol particles is designed by using a multi-channel storage technology. By combining with the functions of single pulse counters and characteristic signal classifiying counters, the storage can offer the capacity up to 65 535 channels, each of which can count to 65 535 particles with a operating speed up to 15 ns. The storage has a simple circuit,and its multiple channel circuits make only up of two MACH435 and two IDT7009 chips.The characteristics of aerosol particles with the sizes of 0.5~20 μm in air is counted,and the particle distribution spectra are obtained. As a key storage component of the aerodynamic particle sizer developed by our institute, this storage satisfies the requirements of the measurement in real time for the speed and capacity.

A new high-performance laser scanning optical system for the Computed Radiography(CR) with a spatial resolution of 10 lp/mm was designed. In view of the performance difference of scanning methods, a scanning arm composed of a pentagonal prism and a scanning object lens was presented to replace the Fθ lens,and then a circular imaging plate was presented to implement the transport mechanism by bending film movement.As the scanning arm can collect synchronously luminescence as a receiving device,the system designed by this method has a simple structure and good performance. The effect of spot sizes on resolution was analyzed and the results show that the smaller the spot size is, the higher the system resolution will be. Many factors effecting on the spot sizes were analyzed in this system,and the dynamic performance of the scanning arm was simulated by using the finite element method in high speed rotating.Furthermore, the influence of an incident light out of the vertical incident flat of pentagonal prism and pentagonal prism displacement errors on the spot sizes were calculated, and the calculation reveals that the largest change of the diameter for the spot sizes is 0.07%,which proves that the system has good tolerance and practicability. Experiments were carried out to verity the performance of laser scanner,and the results indicate that the images obainted have good visual effects and can meet the requirements of industrial inspections.

In order to verify the validity of the liquid crystal adaptive optics imaging technology for the correction of the aberration caused by atmospheric turbulence and to improve the energy utilization of the optical system，Zemax is used to design the liquid crystal adaptive optical system and to evaluate the characteristics of the system.Obtained Modulation Transfer Function(MTF) of the liquid crystal adaptive optical system is very closed to the diffraction limit and the modulus of the MTF is 0.4 at 50 lp/mm.For the specific requirements of detection and correction for a optical path in the open-loop adaptive optical system,the specific tolerance principle is established.According to the tolerance analysis, it is shown that the adaptive optical system has a more relaxed tolerance condition,and it is easier to achieve processing and alignment.The limited resolution of the CCD is 31 lp/mm,which means the resources of CCD has been utilized effectively.After matching a 1 200 mm telescope,the focal length of the whole optical system is 19.9 m, the F number is 16 and the peak-valve(PV) value is 0.031 4λ.

The principle of a lock-in thermography for non-destructive tests was researched and the evaluation, defect depth measurement and its application to the detection of honeycomb structure materials and welding bearings were introduced.A Finite Difference Model(FDM) of 2D heat conduction was established and it then was used to compute the temperature variety process on the surface of samples under the condition of sine law modulated heat flux. The lock-in processing method was applied to extract the quasi-steady state temperature variety of the defect and non-defect regions and the phase differences between them was computed. Furthermore, a thermal-electronic equivalence modeling was established by analog to the fundamental laws of heat and electricity, and it was used to simulate the lock-in thermography. The relation between defect depth and phase difference of both incident and reflected thermal waves was obtained. Finally,non-destructive tests were carried out on a honeycomb structure sample with simulated defects and a real welding bearing by the lock-in thermography. Experimental results indicate that the phase deference between defect and non-defect regions obtained by the finite difference model and thermal-electrical equivalence modeling is close to the experimental result,and the bias error is less than 5% as well. The lock -in thermography can rapidly and exactly detect defect sizes and positions, and can be also used in the measurement for the curve surface of a structure.

To design a SX-700 monochromator for Shanghai Synchrotron Radiation Facility (SSRF) and to enable its main design index, the rotation angle repeatability of scanning photon energy,to be less than 0.43″, the error sources affecting the rotation angle repeatability of the grating sine mechanism are investigated and then the grating sine mechanism is simulated numerically by using the finite element software ANSYS. The errors for the rotation-angle-repeatability of the grating sine mechanism are analyzed according to the results of the numerical simulation, which shows that the rotation-angle-repeatability is 0.28″.Based on the analysis,a SX-700 monochromator is designed,and the angle repeatability of the grating sine mechanism is measured with an autocollimator system designed by us.Measured results indicate that the rotation angle repeatability of the designed monochromator is 0.15″,which meets the requirements of the grating sine mechanism for the rotation-angle-repeatability.

As the quality of filter in a solar magnetic field telescope with a birefringent filter directly affects the transmission band and the measurement of solar magnetic field,this paper researches the error factors that causes the shift of transmission band. By using computer program, the ray trace is simulated completely,and the variation of transmission band with different errors is obtained accurately. Analysis results provide the primary error terms that cause the band shift, band broadening, and the changes of maximum and minimum. Among these errors, the incident angle, optical axis tilt error of crystal, thickness error of crystal, and the optical axis azimuth error of quarter-wave plate affect the band shift.Moreover, the optical axis azimuth error of crystal affects the band broadening,and the transmission band will be broadened by 0.078% when the error is 2°. The optical axis azimuth error of a half-wave plate in a the wide field effects evidently on the maximum,and the maximum decrease by 0.487% when the error is 2°.Furthermore, the optical axis azimuth error of crystal, retardance error of half-wave plate in the wide field, and the optical axis azimuth error of quarter-wave plate have different effects on the minimum.

This paper introduces the measurement principle of a super-smooth surface by a Grazing X-ray Scattering(GXRS) method and an experimental facility based on an improved X-ray diffractometer. By using three kinds of wafers with different roughnesses as samples,the scattering distribution of the samples are treated by first-order vector perturbation theory. The results indicate that the calculated Power Spectral Density (PSD) by GXRS is in a good agreement with the results obtained from Atomic Force Microscope (AFM). It also analyzes the effects of the slit width of a detector and the divergence of incidence X-ray on experimental results,results show that when the slit width is 0.02 mm and the incidence divergence is 43″,the errors are both lower than 2% in the range of spatial frequency higher than 0.03 μm-1. It is concluded that the measuring errors decrease quickly with the reduces of the slit width and incidence divergence, and the PSD error also decreases quickly with the increase of spatial frequency. The repeatability of the experimental facility is better than 2.6%.

The aspheric surfaces are measured by an infrared interferometer with a long working wavelength (λ=10.6 μm). By using the phase-shifting infrared interferometer, the wavefront aberration between aspheric wavefront and reference spherical wavefront is measured. Then, the theoretical value of the wavefront aberration is computed based on the aspheric surface equation. Finally, the surface deviation of tested asphere is obtained by subtraction of the theoretical wavefront aberration from the measured one. Experimental results show that the measured wavefront aberration is 8.64 μm(PV), which is close to the theoretical wavefront aberration(8.11 μm) .Furthermore, the aspheric surface deviation is 1.20 μm(PV). In order to verify the accuracy of this method, the same asphere is measured by using a Computer Generated Hologram(CGH) method,and the results show that the two methods are coincident well. It is concluded that the method has advantages of easy operation and good flexibility,and can meet the measurement requirement of the aspheric surface manufacture.

With the aim to measure the relative curvature radius between the two segments in spherical segmented mirrors and to improve the matching accuracy of segments, a new method utilizing a Shack-Hartmann sensor and a high precision spherometer to measure the relative radius of each spherical segment is presented and an experiment system is also setup. The method firstly uses a co-focus technique to co-focus each segment; then uses the S-H sensor to measure the defocus in the optical axis direction and employs a PZT actuator behind the segments to make the defocus near zero. After the same co-focus process is undertaken again, the relative radius of each segment can be measured by the high precision spherometer. In the experiment, the segmented mirror consists of three spherical hexagonal segments with an opposite side of 300 mm and a curvature radius of 2 000 mm. The analysis and experiment indicate that the precision of the method is about 1 μm, which shows that the method is suitable for the measurement of relative curvature radius of large spherical segmented mirrors.

An optical fluoride probe was fabricated based on Microstructured Polymer Optical Fibers (MPOFs) modified by morin-Al complex doped silica gel films. The structure of this probe was based on microstructured polymer optical fibers with microholes and these microholes could be used as the substrate of sensing materials and minor reaction pools. The deposition of sensing layer was realized by a sol-gel process. When the sol doped with morin-Al was inhaled into the optical fiber, the sensing layer was formed on the inner wall. Furthermore,the trace liquid could be hold in the MPOF, and the process of sensing were carried out in the microholes of MPOF. The sensing process was undertaken based on fluorescence process, and the sensing probe shows different fluorescence intensities to different fluoride ion concentrations in the aqueous solution,for the fluoride ion has a stronger queeching effect to the morin-Al in gel matrix. Experimental results show that the range of response is 5-50 mmol/L under the condition of pH in 4.6.

To test precisely the aspheric surface in a 90 nm nodal point lithography projecting lens, an Offner compensator with three pieces of lenses is presented based on the aberration theory. The equal quantity of spherical error is introduced to compensate all orders of aspheric coefficients and a certain quantity of axial spherical aberration is brought in to compensate the deviation of aspheric surface in a normal direction. The results indicate that primary and high order aberrations are balanced well,therefore the residual aberration is small enough.Furthermore, the design wavelength is 632.8 nm, the MTF exceeds diffraction limit,and the wavefront error(RMS) is less than λ/1 250.As the F-number can achieve 1.64 and the longitudinal aberration is lower than 0.47 μm, the system can satisfy the basic image formation condition. Finally, a loosen distribution of the tolerance is presented based on the accuracy of measuring apparatus. Analysis results show that the total residual wave aberration of the system is less than 0.007 27λ, which satisfies the requirement of assembling accuracy.

In combination with holographic interferometry and the photoresist ashing, a straight and clean photoresist mask with a small line-to-period was fabricated on off-cut silicon (111) wafers. Then,the wet etching method was used to transfer the grating mask pattern on the native oxide layer as the mask of anisotropic etching to obtain the near-ideal grooves of sawtooth. With the blazed grating profile well controlled by this technique, a 1 200 gr/mm blazed grating with a blaze angle of 5.0° and smooth blaze facets about 0.2 nm (RMS) was fabricated. An atomic force microscopy was used to analyze the grating surface,results show that the surface roughness(RMS) is about 0.2 nm,and the diffraction efficiency measurement for the grating shows that the grating can offer excellent blaze properties at the wavelength of 135 nm. It is concluded that high-groove-efficiency blazed gratings used in the vacuum ultraviolet and soft X-ray wavelengths can be easily fabricated by this method at normal or near-normal incidences.

Combined with a strapdown inertial navigation technology, the effect of the technical parameters of a rudder on the performance of a roll autopilot was studied systematically. According to the roll-loop characteristics, the relationship between the roll-loop cut-off frequency and the rudder bandwidth was analyzed; and by comparing the simplified low-order model with the high-order model, the effect of the rudder bandwidth and phase angle on the roll-loop performance was studied based on a frequency domain analysis. In the step response form of a second-order system, the maximum angular velocity of the rudder was determined in combination with the downwash torque with the rolling steady-state command, which ensures the roll autopilot to operate on a linear area under the condition of maneuvering flight. Furthermore, considering the second-order system rudder model with the restrictions on angular velocity and angles and the maximum disturbing torque under different total attack angles, the roll-loop commands and the response state of roll in a saturated nonlinear area was examined,and the stability of roll-loop was proved. Experimental results show that the rudder bandwidth should be no less than 20 Hz and the damping ratio should be 0.6 or more when the missile time constant is 0.3 s, rudder surface moment efficiency is 42 N·m/rad,and the bandwidth of the roll autopilot needs to be more than 50 rad/s.

On the basis of the biological characteristics of human hands, a novel exoskeleton mechanical hand is presented for the rehabilitation of injured fingers. The exoskeleton hand developed by a modular design technology can be regulated for hands with different sizes and for driving fingers to do flexion and abduction/adduction motions independently,and it also can feedback the information of finger joints in real-time during the rehabilitation. The device keeps a rehabilitation force perpendicular to the finger bone under therapy and avoids the soft tissue damage surrounding the finger bone. The one DOF and two DOF structures of the driving mechanism are analyzed and then a kinematical model for the hand exoskeleton is established. Kinematics and dynamics of the hand exoskeleton are analyzed, and their equations are built. Furthermore, a controller architecture using an ARM processor as the kernel is presented based on SPI bus. Finally,the kinematics and dynamics simulations of the hand exoskeleton and the flexion rehabilitation experiment of the index finger are undertaken. The results indicate that the rehabilitation principle and method are correct and the repeatability is less than 5%, which demonstrates that the exoskeleton system can satisfy the rehabilitation requirements of the injured fingers.

The modeling methods for Room Temperature Vulcanization(RTV) adhesive in a reflective mirror structure were investigated. The modelling methods of node-connection(ignoring RTV adhesive)),isotropy(three elements and one element) and anisotropy materials were introduced, respectively. The Finite Element Analysis(FEA) models of lens sets were established by three methods and the simulated mode was analyzed. Furthermore, the mode test equipment was setup and the mode parameters were tested for lens sets. The results show that the error of the first-order free mode frequency between the modeling method of anisotropy and the test method is only 0.3%, and the errors obtained from the three modeling methods of the isotropy of three elements, isotropy of one element and node connecting by are 1.8％, 1.2％ and 13.9%,respectively. From the anlysis and test, it is concluded that the RTV adhesive can not be ignored in FEA and the modeling method of isotropy of one element is a best choice to reduce number of models and to satisfy engineering requirements.

In order to realize the rapid measurement for large dimension work-pieces in industrial fields, a new measuring system based on a stereo vision was proposed and implemented. The key algorithms used in the system, such as feature recognition, camera orientation, stereo matching, object coordinate 3D reconstruction and multi-view point cloud registration, were studied. Firstly, an improved ‘CANNY’ edge detecting method was presented to achieve the sub-pixel localization,and the experiential knowledge was used to eliminate miss-recognized reference points.By fitting point centers of the position, the ring of the reference points was sampled in multi-time to obtain a median and to constructed its ID. Then, the homonymous coded points in each photo pair were searched according to their unique IDs,and the relative orientation and absolute orientation were carried out.Secondly, the multi-image epipolar constraint method was utilized to implement the un-coded point matching and to remove the mismatching.Furthermore, the 3D coordinates of all reference points were calculated by the spatial intersection,and the interior and exterior parameters, image and object coordinates are corrected by the bundle adjustment synchronously. Finally, a binocular structure-light scanner was constructed to acquire the surface detail information of the work-pieces. An improved camera calibration approach was introduced and its calibration accuracy was compared with those of traditional methods.The multi-view point cloud global registration algorithm was also discussed in detail. Experiment results indicate that the new measuring system is suitable for the large work-piece measurement with an accuracy of 0.112 mm/3 m,and it can satisfy the precision and efficiency demands of the large dimension measurement.

The installation accuracy of angle sensors is an important factor relating to the measuring precision of an Articulated Arm Coordinate Measuring Machine (AACMM).In order to realize the dynamic calibration in real time for an AACMM, a coordinate system of the AACMM was established and a compensation expression for angle measuring errors was obtained from analyzing the effect of the off-center installed errors of circular gratings on the angle measurement. Theoretical analysis shows that a little eccentricity could cause a major error, so the angle data of circular gratings should be corrected in practical applications. A method using single-point repeatability as the objective function to identify the eccentricity parameters of the AACMM was introduced based on a simulated annealing algorithm and then it was applied to the identification and correction for the twelve eccentricity parameters of the AACMM. The result demonstrates that the repeatability of the AACMM has improved by 11.3%.

In order to improve the processing precision and quality of a connecting-rod splitting notch and to improve its manufacturing yield, two kinds of connecting-rod products were manufactured and laser processing parameters were also determined. The splitting notch processing on two kinds of connecting rods was carried out by a Nd∶YAG solid laser and then the influence of different cutting parameters on the cutting quality was analyzed and the laser cutting parameters were optimized. The result shows that the laser peak power, clearance between focus and plate, cutting speed, impulse frequency, assistant air pressure, and the angle of laser incidence have a great influence on the processing quality of splitting notch. When the peak power of laser is 2.4 kW and the impulse time is 0.4 ms, the depth of cutting notch is 0.453-0.457 mm. Moreover, when the ratio between impulse frequency and cutting speed is 3, the splitting notch processed is conductive to the splitting of connecting rod in the condition of the minus clearance between focus and plate, which can meet the demand of the splitting quality of M0406 connecting-rods.

In order to balance the response speed and steady state accuracy of flywheels, a new control method combining of the constant switching variable structure control and speed-changed integration control is established on the basis of analysis of a constant switching variable structure control and a speed-changed integration control. The speed-changed integration control with high stable precision can change the accumulation of integration speed to correspond to the size of the deviation,which is able to make up the shortcomings of the constant switching variable structure control with switching characteristics.On the basis of the flywheel motor model and dynamic equation,a control model is established, then the performance of the control model is analyzed and the experiment of speed tracking is carried out. The experimental results indicate that the system dynamic and static performance have been greatly improved. When the sine instruction gives a offset in 1 000 r/min, amplitude in 100 r/min, and the period in 0.01 Hz, the tracking error is 2 r/min. Moreover,the proposed method suppresses the overshoting of the switching range, improves the steady state accuracy within switching range and prevents the bufferiy. It can satisfy the system requirements for higher precision and speed.

The asymmetrical rotated piezoelectric actuator is mainly driven by a sawtooth wave,namely, a kind of asymmetrical wave. On the basis of the ability of symmetrical wave drive and the principle of the converse piezoelectric effect, a design scheme using symmetrical wave to drive the piezoelectric cantilever bimorphs is proposed. The symmetrical wave is acted on the piezoelectric cantilever bimorphs to get inertial impact forces in different directions to drive the rotated actuator to realize the movement. The dynamic model of the rotated actuator is constructed, whose movement principle is also analyzed.An experimental system is built and the rotated actuator’s velocity characteristics under different frequencies and voltages are tested. The results show that the asymmetrical rotated piezoelectric actuator realizes a stable and forward direction movement. When the voltage is 20 V and the frequency is 2 Hz square wave, its average step is up to 12 μrad and the rotation velocity is up to 24 μrad/s. The rotated actuator can provide the maximum stroke in 360°, carrying capacity to 300 g, resolving capability in 5 μrad, and rotation velocity in 4 000 μrad/s.

As traditional optical machining technologies can not test and control the subsurface damage in grinding precisely, a new optical machining process was introduced, in which a Magnetorheological Finish(MRF) was used to replace the lapping and to follow the grinding processing. A experiment to remove the subsurface damage caused by grinding was carried out by using a KDMFR-1000F polishing machine and KDMRW-2 water based MR. The experimental results indicate that after rough polishing for 156 min firstly, the 50 μm (depth) subsurface damage of the K9 flat glass has been removed and the surface roughness is 0.926 nm. Furthermore, with a fine polishing for 17.5 min, the 200 nm(depth) glass surface can be removed and the ripples caused by rough polishing are also eliminated, which improves the surface roughness to 0.575 nm. These results show that the propose optical machining processing with MRF can remove effectively the subsurface damage caused by grinding and can provide a high surface roughness below 1 nm.

In order to maintain a stable spin and high-speed rotation of superconducting spherical rotors at low temperatures, a spin drive device for superconducting rotors is designed based on the Meissner effect. The spin drive device includes a superconducting stator and a superconducting spherical rotor. The stator is fitted two-phase coils and the rotor is a hollow structure with four windows in its inner wall. The electromagnetic field generated by the stator coils can produce a rotating torque on the windows in the inner wall to drive the rotor to rotate. Then,the driving force is calculated using the Ansoft software, and analysis results show that the driving torque is approximately in proportional to the square of drive current. Rotation experiments are performed at 4.2 K, 30 Pa and rotation speed is up to 8 512 r/min in a drive current of 30 A. Experimental results indicate that the drive device can accelerate the rotor to an operating speed above 8 500 r/min, which provides valuable references for the further improvement of the design parameters of drive devices and the rotation stability of superconducting spherical rotors.

A novel 3D precision displacement system of large travel, nanometer level and displacement measurement by itself is developed to satisfy the need of precision displacement. The system is designed with a modular structure, in which the driving mechanisms of three directions adopt the same design structure and calls as X direction, Y direction and Z direction 1D worktables, respectively. The dual-stage actuators of coarse and fine driving have been applied in the precision displacement system in X, Y and Z directions and three sets of metrology gratings are installed in X, Y and Z directions respectively. In every direction,the AC servomotor combining with a precision lead screw and a linear guide is used to actuate the coarse driving,and a piezoelectric micro-displacement actuator combining with a flexure hinge is used to actuate the fine driving and then a set of metrology grating is set for the displacement measurements of the coarse driving and fine driving. Therefore the need of large travel, nanometer level and displacement measurement by itself of the displacement system can be satisfied. The structure design of the displacement system is introduced and the displacement resolution, measuring principle and the motion performance of this displacement system are also analyzed in details. Experiments indicate that the displacement difference between actual and setting are no more than ±0.030,±0.028 and ±0.033 μm respectively in X, Y and Z worktables in a range of 40 mm, which verifies the effectiveness of design of the displacement system and provides the theoretical basis for its development.

A sweep system with a double-helical screen whose rotation is driven by a motor is established to produce a steady and unique imaging space to realize real-time and high-resolution volumetric three-dimensional imaging. The imaging characteristics of projection spaces created by swept volume and static volume techniques are compared and analyzed,and the processing schemes of screen structure are designed. Using high strength photosensitive translucent resin materials and a supporting wall structure,the system is manufactured by rapid prototyping and directly digital manufacturing. Furthermore, the three dimensional model of helical sweep screen is established by Solidworks software and the dynamic testing is analyzed by the COSMOSWorks module. The simulation results show that the maximum displacement of screen rotating is 0.013 mm at 600 r/min,which is far less than the visual resolution range of realistic image synthesis, so the projection space based on the helical sweep screen can match imaging requirements. Finally,a system platform is built on the basis of the existing engineering and technological level. Experimental results indicate that the platform can produce a steady projection space (25 cm×Ф50 cm), and can supply excellent volumetric three-dimensional images.

The preload and precompact capacity of a two-piece outer ring self-aligning ball bearing are analyzed in this paper to ensure the preload effectivity. This bearing has the merits both from a double row angular contact ball bearing and a double row self-aligning ball bearing, so it not only can be preloaded to enhance stiffness, but also can self-align to compensate the misalignment. The maximum misalignment angle reaches 3°. In order to be preloaded properly, the outer ring is consisted of two spherical inner face raceways, which forms a spherical surface whose center is common to the bearing center and a in-between spacer. The preload is controlled by adjusting the thickness of the spacer. The relationship between preload and bearing supporting is analysed and formulated with the help of a mechanic theory. Meanwhile, based on the Hertz contact theory, the formula to determine the spacer thickness is given. This kind of bearing is adopted in a LAMOST telescope,test results show that the radial runout is less than 0.02 mm and axial runout is less than 0.03 mm for a φ1 100 mm bearing at an arbitrary angle of 50°. The tracking accuracy of focal rotation is better than 0.3″supported by this kind of bearings.

In order to achieve a rapid design and verify the performance of MEMS products, a new approach suited to establishing equivalent electrical representations of an integrated MEMS but different from the conventional signal-flow principle is proposed in this paper. Based on the structured design methodology of the MEMS,i.e., nodal analysis method, this approach starts from the functional decomposition of the system and MEMS device. Then, the nodal models of these decomposed elements (emphases laid on those transductional ones) are created and transformed as equivalent networks or components by rule of a certain electrical analogy, F-V analogy. Finally, according to the constraint relations for node variables (General Kirchhoff’s law), the equivalent networks (components) are hierarchically reconstructed as device-level models and system-level equivalent circuits. Aiming at the analysis and design of a comb-shaped electrostatic feedback micro-accelerometer, the approach is specifically illustrated and validated. The achieved “computational prototype” of such a mixed-domain system can be expediently implemented by OrCAD. Moreover, compared with VHDL-AMS models, it provides that proposed model has more explicit physical conception and more less computation time. It indicates that the approach has its application value in analysis and design of complex integrated MEMSs.

With the aim to model the hysteretic curve between the output displacement and applied voltage of the WTYD type piezoceramic micro-actuators, the Bouc-Wen model to characterize the hysteretic relationship between the output displacement and applied voltage of the piezoceramic micro-actuators is put forward by using the Bouc-Wen hysteretic operator to simulate the hysteretic component and then a corresponding parameter identification method is established. To evaluate the effectiveness of the developed model and the parameter identification method, the corresponding experimental setup is established and the model is validated. Research results indicate that the maximal absolute and relative errors of the proposed Bouc-Wen model are less than 3.78 μm and 5.79% respectively, which shows the proposed Bouc-Wen model and the parameter identification method can well simulate the hysteretic characteristics of the WTYD type piezoceramic micro-actuators.

The onboard calibration is a basis of a spaceborne Hyper-spectral Imager(HSI) to obtain accurately quantified spectral imaging data. In order to enhance the stability of the tungsten-halogen lamps of the spaceborne calibration integral sphere and to reduce the change of the integral sphere radiance, a kind of current stabilized source for the tungsten-halogen lamps was developed. The operating principle and current stabilized circuit with a soft start characteristic were introduced. And the effects of some performance parameters, inputting voltage load, temperature and so on , on the properties of current stabilized source were analyzed. Then a test was carried out for the current stabilized source. Experimental results show that the current stability can be up to 0.037% by changing the transistor's gain to adjust the time of soft start, collecting the voltage of the high precision resistor and computing the value of the current. Furthermore, the current stability can be up to 0.043% after the repetition. These results also indicate that the accuracy of the current stability can satisfy the requirements that the change of integrating sphere radiance should be less than 1%. The integrating sphere system has been successfully applied to a HSI onboard calibration.

An active disturbance rejection controller for an electro-optical tracking servo system is presented to track maneuvering targets fast and accurately and then its work principle is investigated. Based on the structure analysis of a tracking system, the target velocity is taken as the exterior unknown disturbance and the system parameter change is used as the interior unknown disturbance. A extend state observer and a tracking differentiator are used to estimate the disturbance accurately from the input and output information of system response, then the controller can compensate the disturbance further. Experimental results indicate that the system can fast track maneuvering targets at a maximal angular velocity of 40 mrad/s and an maximal angular acceleration of 8 mrad/s2 while the maximal tracking error and the maximal overshoot are less than 0.1 mrad and 10% respectively.These results show that the scheme has a good structure and robust performance, and can satisfy the system requirements without using the sensor to measure the target state.

Speaker clustering is a key component in many speech processing applications. To solve the problem of error propagating in the posterior clustering caused by the traditional online clustering, an improved online speaker clustering algorithm based on a decision tree is proposed. Unlike typical online clustering approaches, the proposed method constructs a decision tree to increase branches and to distinguish an audio segment clustering to reduce effectively the effect of error distinguishing on the posterior clustering. To shorten the operation time, a pruning strategy for candidate-elimination is also presented. Experiments indicate that the algorithm achieves good performance on both precision and speed. By using this method, the average speaker purity and the average cluster purity have improved by 0.9% and 1.1% respectively, and the time consuming is reduced by 57%. Experiments also show that this method is effective for improving the performance of the unsupervised adaptation as compared with the true speaker-condition.

To overcome the shortcomings of the traditional Mean-shift algorithm for object tracking such as the localization error caused by background pixels and the tracking failure from the object occlusion,an improved Mean-shift algorithm is proposed. Firstly, according to the difference of color distribution between the object and the background in the initial frame, a log-likelihood image is set up to select the discriminative color features for object modeling, and then the candidate modeling is established by the same way. By above operation,the effect of background pixels on the image has reduced greatly.Secondly, the whole candidate region is separated into several overlapped fragments, and every fragment is iterated by the Mean-shift.Then, the object localization is reset by the location of fragment in the candidate region, which matches mostly to the corresponding fragment in the object region. Experimental results show that the fragment based on the Mean-shift is very robust to partial occlusion. Furthermore,when object is severely occluded, the linear prediction can be used to estimate the probable location of the object in the next frame. These results prove that the tracking using the improved Mean-shift algorithms has good localization precision and is robust to partial and severe occlusions.

In combination of the characteristic of JPEG2000 and the network architecture of Wireless Sensor Networks (WSNs), a multi-node cooperative JPEG2000 image compression method based on neighbor clusters is proposed by using the concept of in network processing to improve their energy,meomory and computional power. Firstly, the images captured by the camera node are partitioned into tiles and the adaptive bit rate is allocated by a optimum method based on gradient magnitudes. Then the tiles are sent to the neighbor clusters and compressed by multiple nodes cooperatively to minimize the total energy consumption of the network. Simulation results show that the proposed image compression method not only realizes the JPEG2000 compression of big size images in the WSNs, but also balances the energy load among all nodes. Compared with the compressing image before sending it to the base station, the proposed method has decreased the energy consumption of the camera node to 3.4%. These results show that the lifetime period of the network has improved by 7 times.

In order to improve the assembly performance of Optical Burst Switching (OBS) networks, an adaptive assembly strategy for the edge node of OBS was presented in this paper. To be different from the traditional assembly strategy with a fixed threshold system, the proposed strategy measured the network traffic flow and chose a suitable assembly threshold dynamically by introducing a cross counter.Moreover, the step length of the assembly thresshold was modified by comparing the type of assembly threshold with the former one. Simulation results show that the strategy can reduce the burst loss probability by 69.07% and 38.89% as compared with the existing assembly strategy. The edge node hardware structure for a OBS testing bed was designed and realized,and the functions of assembly and schedule based on the hardware structure were tested, meanwhile, the prospective goal was achieved. Results show that the novel strategy not only can adjust the assembly threshold according to the traffic flow, but also can have lower burst loss probability under a strong self-similar case.

To alleviate the effect of local highlight and self occlusion of a random-pattern-projection-based binocular stereo measurement system, a novel method by using a single camera and the projector as a monocular measurement unit was presented. Firstly, a simple and effective calibration algorithm was proposed to construct the line functions of the rays emitted from every point of the random pattern plate through a projector lens,then the calibration was carried out by just taking several images (called calibrated images) of a white board with random illumination in different orientations. It is unnecessary to calibrate the distortion of projector lens, and the system precision is not affected by the distortion. Then, the object image captured in random illumination was matched with the calibrated image at sub-pixel location, and the 3D point cloud data of the object were obtained by triangulation principle. Finally, the standard plane and cylinder were measured to verify the accuracy of the proposed method, which demonstrates that the measurement uncertainty is less than 0.05 mm (3σ). Several other measurement examples indicate that two monocular measurement units working together can effectively avoid point losing caused by the highlight and occlusion.

In order to eliminate the cloud and mist from remote sensing images captured by cameras, a new non-local means algorithm is proposed to process the cloud and mist noise in remote sensing images. Based on the gradient feature under the shadow of cloud and mist in the remote sensing images, it is found that the intensity of the image declines obviously while the gradient only has a little change,therefore, the gradient information can be coupled into the weight computation. Then, the redundant information in image sequences is used to compute the new weights and the new weights are used to restore the image sequences. Two remote sensing image sequences are taken by UltraCamD in Xinjiang and Shanxi in China, and results show that the quality of restored image is improved significantly by this algorithm. Compared with the original images,the PSNR by proposed method has improved by more than 9 dB. Experiments show that the proposed algorithm can effectively restore remote sensing images without the motion estimation for the cloud and camera as well as the noise model.

A real-time color video capture system is established to realize the color video capturing by an area array CCD . The hardware and software designs of the color video capture system of area array CCD ICX424AQ presented by Sony company are analyzed, and the structure parameters of the area-array CCD and the color video gathering principle of the capature system are introduced. Then, the CCD control sequence and the timing logic of the whole capture system is realized. Furthermore,the noises of the video signal (KTC noise and 1/f noise) are filtered by using the Correlated Double Sampling (CDS) technique, and the signal-to-noise ratio of the system is enhanced. Because the area array CCD image sensor is covered by a Bayer Color Filter Array (CFA), each pixel has only one component of three primary colors. In order to obtain full chromaticity at every pixel, an enhanced bilinear algorithm is presented to obtain a compromise solution between the complex of hardware implementation and image quality through interpolating. The CCD is worked under progressive scan mode and all pixel signals can be read out simultaneously at the exposing time of 0.32 ms. The whole system is controlled by a Field Programming Gate Array(FPGA),and the pixel data readout is interpolated and then transmitted by the transmitting chip SiI1162. Finally, the designed video is displayed on a TFT-LCD in real time.