Tolerance modeling is used to present the tolerance accurately in CAD system and interpret the semantics correctly. In order to present the tolerance semantics in CAD system， small displacement torsor(SDT) was introduced in tolerance modeling. A new method of mathematical model of size tolerance for plane was proposed. The representation approaches of geometric elements based on SDT were introduced firstly. According to constraint, conditions of dimension chain， size tolerance for plane was divided into two types. SDTs have been used for representing the deviations. The constraint relationships of two types were developed systematically. The mathematical models of two size tolerances were founded which can interpret the semantics of size tolerance completely and can be used by the following processing. Finally， an example was given to illustrate the application of the proposed model in tolerance synthesis. The different torsors were given according to assembly requirements. Then the tolerances of plane size were obtained. The result shows that the size tolerance for plane can be figured out reasonably．

Four separating principles applied to solve physical contradiction depended on experience of engineering technical personnel in theory of invention problem solving. The procedures and innovating principles of solving physical contradiction with space separating principle were introduced in technical system and conceptual design frame was applied to expound condition of applying space-separating principle in mechanism design, which was physical contradiction with the property of mutual independence and accompany in requirement domain meeting realization of function domain. According to design of clamping test apparatus of water-jet peen hardening, physical contradiction was defined based on its design requirement and applied force was determined as contradiction parameter. The requirement of the applied force met condition of applying space-separating principle and the space-separating principle was determined. In accordance with procedures of space-separating principle for solving physical contradiction the two non-crossed operating spaces were selected. The “taking-off” principle of the ten innovating principles in space-separating principle was applied and the innovating program of the test apparatus was created. Space-separating method of mechanism design is composed of condition, procedures and innovating principle of applying space principle for solving physical contradiction in the process of mechanism design. The method is verified through the forming process of innovating design program on clamping test apparatus of water-jet peen hardening.

 To solve the problem of the traditional cathode with fixed tooth in processing mixed rifling， the design to divide work part of the cathode into 10 wheel plates was presented. Each wheel plate meshing with the gear possessing different modulus and number of teeth of gear， was driven by the micromotor inserting in the cathode body and rotate at various angles so that the cathode working tooth can be consistent with the direction of rifling angle separately. However， the separation， cavitations， and eddy current appeared near the ladder-shaped surface on each working tooth frequently. Four schemes to optimize tooth shape were designed， the time-averaged drag coefficient and ablation volume was calculated by programming. The results show that the relative error of the ablation volume by the fourth scheme is the smallest compared with the theoretical， the time-averaged drag coefficient reduces 70% compared with the non-modification. Finally， the shape parameter s=0.5 mm of the riblet structure on the working tooth was adopted for further optimization and the drag-reduction achieved 14.6%．

 Based on the Bekker soil pressure-bearing model， Janosi shear model and principles of plastic deformation, the interaction model of arch support of the lander and lunar soil and the aluminum honeycomb model were built separately， and on this basement a more accurate overall multibody dynamic model of lander was established by the ADAMS software. Combined with the measure method of force-angle stability， the authors have proposed a proper criterion for the safety of the soft landing stability for the lander. For the different circumstances of the moon surface and initial landing state of the lander， the authors have simulated the collision process of the soft landing on the rigid or simulative moon surface for the lander through numerical calculation. The impact of the landing circumstances and initial conditions on the stability of soft landing was specially analyzed， and the stability boundary curve of the relationship between different yaw angles and ultimate lateral speeds when the lander overturning is also obtained. Meanwhile， according to the stability boundary curve， the worst working case is found out， which happens when the yaw angle is 22.5° when the allowance of the ultimate lateral speeds is the smallest， and thereby the results provide the guidelines for choosing moon environment and initial conditions for implementing soft landing of the lander successfully．

 Bond-graph modeling approach to a hydraulic system was discussed. The bond-graph model of damper test-bed's hydraulic system was built according to the power bond graph theory. This model's dynamic simulation results， such as the velocity response and pressure response， were indicated in the environment of 20-sim software. Simulation results show that bond-graph modeling approach is feasible and correct. Further more， the Simulink model was built for a result contrast. Contrastive results prove that the modeling method is reliable. So， the whole result provides a new way in the field of dynamic modeling and simulation for hydraulic system．

According to entity modeling and finite element model analysis by computer software and testing experiment， a new structure of three-dimensional fine-tuning frame for avalanche photodiode receiver on one satellite laser ranging(SLR) system was designed. First， the 3D entity model of the frame was built by using UG software, then the finite element model was established by finite element software MSC.Patran to put up linear static and modal analysis， finally the vibration and precision tests were done to the frame entity. The results of the vibration test and the finite element analysis are consistent， which demonstrates the reliability of the finite element analysis. According to the design and analysis by software and the tests， the design of the frame is satisfied with the project requirement and can achieve the precise fine-tuning of the avalanche photodiode to make it work well．

In order to improve the accuracy of mathematical model of pneumatic artificial muscles(PAM) and enhance its usefulness， the experimental study has been carried out to test the working characteristics parameters of pneumatic artificial muscles， and experiment on mathematical model of describing characteristics of pneumatic artificial muscle was built. The static experimental system was set up for the characteristics of pneumatic artificial muscle， and the working characteristics of pneumatic artificial muscles for various indicators were measured. By least square method， the inflation pressure， load， and contraction ratio were combined with coefficient matrix organically and the experiment mathematical model of pneumatic artificial muscle was established. For a certain pneumatic artificial muscles， the built model is universal. Therefore， the conclusions have important significance for the control system design and implementation of accurate control of pneumatic artificial muscles．

 To reveal the influence disciplines of filling viscoelastic materials on vibration characteristic of circular saws， comparative researches were carried out on damping and dynamic character of unfluted saws and grooved ones filled with padding. Firstly， modal damping ratio was calculated on the basis of the Modal Strain Energy Method， structure damping were expressed by Rayleigh damping， and modal damping constant of two circular saw models were obtained; then， the response of vibration and curves of attenuation were presented by the transient dynamic analysis of circular saw， from which influence of filling materials on vibration of circular saw was analyzed. Finally， the curves of vibration response of two circular saw blade were obtained by means of test modal analysis. By comparing the numerical analysis with the experimental data， the two results agreed well， which proved the reliability of simulating method. The results show that， under the same dynamics condition， vibration frequency of each measuring point will decrease and the course of attenuation will be cut down due to filling viscoelastic materials. The results provide effective theory support for the inventory design and development of low-noise circular saw．

With the classic mechanics model, qualitydampingspring coiling the under-damped second-order linear system for research object, when the damping coefficient and intrinsic frequency of the system were subject to multiplicative Gaussian white noise, this article studied detailedly that stochastic resonance of the under-damped second-order linear system were used to resolve multiplicative noise. Theoretical analysis showed that this system produced the phenomenon of stochastic resonance. The average output amplitude gain (OAG) of this system presented not-monotonous variety. Under certain conditions, OAG was greater than that of second-order linear system with no noise, and adjusted the appropriate system parameters and noise intensity could improve the output amplitude gain. Therefore, the article used visual simulation software SIMULINK to establish a linear system simulation map of stochastic resonance and simulate some examples. Simulation further shows that appropriate system parameters can achieve weak signal detection of under-damped second-order linear system in the noise background so long as the system is in the resonance region. So it confirms that this method resolves multiplicative noise feasibly and effectively.

 In order to analyze the double lay long span space reticulate shells with high precise， the comprehensive analysis was carried out by the response spectrum method and the time history response method. The difference of analysis by the two methods was put forward， and then by means of regress method， the modified coefficients which used to correct the analysis result of the response spectrum method were studied. So the practical modified response spectrum method was put forward with the modified coefficient. The error caused by the response spectrum method is decreased. The method is not only simple but also high precise through the example. The calculation shows that the method is efficient and precise in the seismic response analysis of the complicate structures， such as double lay long span space reticulate shells. It provides the theoretical basis and guidance with convenience．

To achieve a precision positioning control of welding torch for welding mobile robot， this study put forward a novel method to design control system. The method realized a sensorless high-precision open loop control based on the adjustment of traveling-wave ultrasonic motor micro-step operating time when the welding torch followed the welding line. EDA technique and single chip processor were taken advantages of respectively. A combination of CPLD and single chip processor completed micor-step control to double traveling-wave ultrasonic motors. Experiment results show that the controller has features of high precision， efficiency， better maintainability and positions the welding torch with high accuracy without using high precision displacement sensor. The methods and results put forward have features of versatility and have broad prospect in application of  XY precision positioning table of two-dimension using traveling-wave ultrasonic motor．

 Since the fumigation bed temperature control has the features of nonlinearity and large hysteresis， a precise temperature control system based on single chip microcomputer was designed to shorten the lag time and reduce overshoot， in which the authors adopted differential preceding PID calculating with Pulse Width Modulation(PWM) technology. The test results indicate that effect of differential preceding PID control is better than that of other normal PID control. This system has good control performance and dynamic performance， the control system is stable and reliable， and the detection circuit and the serial communication program both have good versatility and portability．

 In order to reduce the velocity and acceleration of the antenna nodes， and the impact force on the satellite antenna as well，the deployment process of the tetrahedral truss antenna was analyzed, and  a method of exerting an active force to control the deployment process was given. An antenna model with 2 m caliber was fabricated. Based on the model， the control method was tested. Using the non-contact computer vision measurement system and the MATLAB program， the velocity and acceleration of the antenna nodes during the test was got. The test results show that the velocity and acceleration of the antenna nodes， and the impact force on the satellite are reduced efficiently after the control method was taken. The feasibility of the control method is confirmed．

In practical test， the output may be various when it fails. A great deal of information would be ignored if binary test was applied. Test precision and efficiency would also be decreased. Diagnosis strategy design algorithm based on extended multivalued dependency matrix was put forward. Multivalued dependency matrix was extended into binary dependency matrix， and then diagnosis strategy was designed based on AO* algorithm. Finally， the example proves that fault isolation precision is improved and the algorithm is effective. It offers an efficient algorithm to the diagnosis strategy design of uncertain system．

 CPW and fractal structure used together in antenna design have unique advantages in broadening the bandwidth of the antenna. A novel copper-cash-shaped ultrawideband(UWB) fractal antenna was proposed. By using fractal slot， the CPW-fed antenna had a wide bandwidth. Surface current distribution， return loss， directional patterns and gain of the antenna were investigated. Three iterative fractal antenna was fabricated and measured. The measured results show that the bandwidth is 2.6~16 GHz， larger than 6:1， and found in good agreement with the simulated results. Thus this antenna can be widely used in compact structure and UWB antenna design.

This paper designed an adjusting reflector with two-dimension, to compensate for the laser beam’s excursion of the laser, so as to improve the alignment accuracy of the high-energy laser launching system. This mechanism used double floors of a same base, and arc-faces with small curvature which was tangential to a bevel of little obliquity to achieve angle adjustment. It also had two kinds of control as manual and automatic. Besides advantages of angel adjustment with high precision and high stability, the new type adjusting system with two-dimension is also convenient to install, maintain with small volume, handy to adjust and can be used whether there is weight condition. Therefore it not only can be applied to the adjustment of light path, but also to the aviation and space industry, civil industry and other fields which have high requirement in angle adjustment．