元动作装配单元的可靠与否是机械产品能否稳定运行的关键所在。由于机械产品的多层次结构,使整机性能的分析与建模变得困难。开展了从整机到元动作的映射研究,提取出典型的元动作装配单元。根据元动作装配单元的实际装配行为选取过盈装

为获得具有较高运动精度、无寄生运动、放大比较大且可调的微动平台,基于直圆型柔性铰链的导向、传动原理及机构杠杆原理,设计出一种对称驱动且放大比可调的二级微动放大机构(设计放大比为1∶5),并提出压电陶瓷致动器驱动微动放大机构

微动机构是实现超精密定位的重要部件。本文基于平衡附加力原理设计一种放大比可调的精密微动放大机构，并完成机构强度、动态、运动学分析。基于平衡附加力原理设计了一种无附加力及位移的微动放大机构，可确保运动过程的安全性及精密性。采用有限元法完成了机构强度分析，结果表明系统强度满足设计要求。采用有限元法及实验分析完成了机构的动态性能分析，二者最大相对误差为9.41%,结果表明机构动态性能符合设计要求且运动过程中不会发生共振。采用理论计算、有限元分析及实验分析完成了机构运动学分析，在完成3种方法线性拟合基础上解析了机构运动方程，微动放大机构理论与实验分析相对误差为9.4%（二者最大绝对误差为0.85μm）,有限元与实验分析相对误差为7.8%（二者最大绝对误差为0.57μm）,运动线性拟合相关系数不小于0.998。结果表明微动放大机构具有强度及动态性能优良、运动精密、线性度高等优点。

A micro-drive system is a key part of macro-micro-drive technology and precision positioning technology in which a micro-drive reduction system can provide more precise motion and suitable small space motion. Therefore, it is necessary to study precision micro-drive reduction systems. In this paper, based on the design of a micro-drive reduction mechanism without force and displacement in non-motion direction, a precision micro-drive reduction system driven by a piezoelectric ceramic actuator (PZT) was designed, and the strength, dynamic and motion performance of the system was analyzed. First, based on the principle of a flexure hinge lever and the principle of balanced additional force, a type of precision micro-drive reduction mechanism with an adjustable reduction ratio was designed. Second, the strength performance of the system was analyzed by finite element analysis, and the dynamic performance of the system was analyzed by finite element analysis and experiments. Finally, the kinematic performance of the system was analyzed by theoretical analysis, the finite element method and experiment, and the motion linear equation was calculated based on the linear fitting equations of three methods. The study results showed that the system had good strength and dynamic performances, and the system's motion had the advantages of high precision and good linearity. This research has certain reference value for the design and performance research of micro-drive mechanisms.

In this paper, a sub-arc-second macro/micro dual-drive rotary system is designed, and the continuous compensation of the system error and its experimental research are completed. First, the macro-drive system is driven by a direct-drive motor, and the micro-drive system uses a piezoelectric ceramic to drive the micro-drive rotary mechanism; the system uses a micro-drive system to compensate the motion error of the macro-drive system, and uses circular grating to feedback the displacement of the macro/micro total output turntable to form a macro/micro dual-drive closed-loop control system. Second, based on the establishment of the system error model, the design of the system's continuous error compensation scheme is completed. Finally, the positioning accuracy testing of the system, direct error compensation of the macro-drive, manual error compensation of the macro-drive, error compensation performance of the micro-drive part and macro/micro compensation of the system are carried out in the study. The results show that the repeated positioning error and the positioning error of the system are reduced by 78.8% and 95.2%, respectively, after macro/micro compensation. The correctness and effectiveness of the designed system design, error compensation and control method are verified through performance tests, and its positioning accuracy is verified to the sub-arc-second (0.1 arcsecond) level. The research in this paper has important reference value for the development of ultra-precision macro/micro dual-drive technology.

In order to clearly express the reliability dynamic change process of mechanical meta-action units with recessive fault on continuous time series, this paper proposes a reliability analysis method for multistate systems with recessive failures of mechanical meta-action units based on the fusion of vibration signal analysis and Markov process. By analyzing the vibration signal, five major recessive fault types of mechanical meta-action units are determined. By analyzing the experimental data and based on the average time of the first occurrence of five major recessive faults, a performance level state representation model of mechanical meta-action unit based on fault importance weight is established. Then, based on the repairable characteristics of the mechanical element action unit, the two-way state transition model and state probability differential equation of mechanical meta-action units are established, and the state probability of each state is obtained. Next, under the condition of determining the initial state, the change process curves of the instantaneous availability, instantaneous average performance, and instantaneous average performance deficit of the mechanical meta-action unit are obtained by solving the reliability index calculation formula. Finally, this paper takes the worm rotation meta-action unit as an example to verify the law and probability of the state transition of the mechanical meta-action unit, and the performance level change accompanying the state transition process, by analyzing the failure modes and causes of recessive faults, the corresponding reliability control measures are formulated, and the control effects before and after reliability control are analyzed. The research results show that this method can effectively improve the accuracy of the state probability when calculating the state probability of each state, and compared with the discrete Markov model, when studying the reliability of complex multistate systems, this method can dynamically describe the change process of state probability, instantaneous availability, instantaneous average performance, and instantaneous average performance deficit in real time under the condition of continuous time-dependent variables. It has certain guiding significance for the reliability analysis of mechanical element action units in the long-term range.

In order to obtain motion with large travel and high precision, the micro-drive system is used to compensate for the motion error of the macro-drive system in the macro/micro dual-drive system. The research on the micro-drive rotary system lags behind the micro-drive linear system, so it is of great significance to study the designing and error compensation performance of a precision micro-drive rotary system. In this paper, a precision micro-drive rotary system is designed, the error compensation scheme of the system is proposed, and the system feasibility in design and error compensation is tested by FEM simulation analysis and performance experiments. Firstly, a precision micro-drive rotary system is designed to provide high-precision rotary motion, which consists of a micro rotary mechanism and PZT. In the system, the micro rotary mechanism is developed based on the compound motion principle of flexure hinge, which can accurately transform an input of linear motion into an output of rotary motion according to a certain relationship. Secondly, for finishing the error compensation scheme of the system, the maximum compensation modifier theta max ' is proposed based on the analysis of error compensation equations of point-to-point motion and continuous motion. Finally, in order to facilitate the use of engineering, the driven voltage equation of error compensation is derived by the error compensation performance experiment. The simulation and experiment results indicate that both the design and error-compensation-range of the system satisfy the needs of practical application.

The guide stiffness performance directly affects the motion of the micromechanism in accuracy and security. Therefore, it is crucial to analyze the guide stiffness precisely. In this paper, a high-precision guide stiffness analysis method for the micromechanism by the boundary element method (BEM) is proposed. The validity and accuracy of the analysis method are tested by a guide stiffness experiment. In order to ensure the accuracy and safety during the micromechanism motion, a guiding unit of the micromechanism was designed based on the guiding principle. The guiding unit can provide parasitic motion and additional force in the motion of the micromechanism. Then, the stiffness equations of the beam element are derived by the boundary element method. The stiffness equation of straight circular flexure hinge is analyzed by rigid discretization and rigid combination, and the guide stiffness of the mechanism is investigated by rigid combination. Finally, according to the actual situation, the stiffness matrix of the guide rail (K-b) was proposed, and the analytical value of the guide stiffness was calculated to be 22.2 N/mu m. The guide stiffness performance experiment was completed, and the experimental value is 22.3 N/mu m. Therefore, the error between the analysis method and the experimental results is 0.45%. This study provides a new method for the stiffness analysis of high-precision micromechanisms and presents a reference for the design and stiffness analysis of complex structures. This method is helpful for stiffness analysis of the microrotary mechanism with high accuracy.