微/纳米定位平台的动态特性分析与试验

为了分析微/纳传动平台的动态特性,应用拉格朗日方程,建立5自由度微/纳米定位平台的动力学模型,推导出固有频率及阶跃响应的解析式.采用有限元方法,仿真得到平台的前5阶固有频率和模态阵型.在不同驱动频率和不同加载下,分别进行静、动态试验,结果表明,平台的开环调节时间为0.812s;驱动频率为100Hz时,发生共振现象;加载小于10N时,平台具有较好的稳定性;动态试验得到压电陶瓷、电容传感器和平台的分辨率分别为4、10和45nm,且平台的重复定位精度为0.6μm.     

微/纳传动平台的位移耦合分析

根据机械设计、机械原理、有限元法及线性分析理论,建立微/纳传动平台的有限元模型,推导该平台的位移耦合计算公式,得到该平台沿各方向运动的解耦方程.结合耦合分析图,分析微/纳传动平台多尺度的位移耦合影响,获得该平台沿X、Y、Z轴移动以及绕X、Y轴转动的位移耦合规律,其中沿Z向运动引起的位移耦合最小,定位精度最高;沿X、Y向运动引起的位移耦合最大,对位移耦合影响较大的运动分支进行位移补偿.通过搭建的实验平台进行测试,将实验结果与有限元仿真和理论计算结果进行对比分析,结果基本一致,验证了该平台位移耦合分析方法的正确性.     

K-H类NW型行星运动机构的参数优化设计

对K-H类NW型行星运动输出机构在给定增速比的条件下进行了传动方案、参数优化设计,得出了这种机构在尺寸较小时的一组最优参数及传动方案,从而为这一机构的应用开发奠定了理论基础.     

叶片式风动锚杆钻机旋转切削机构优化设计

通过对叶片式风动锚杆钻机旋转切削机构的参数分析 ,以体积最小为目标 ,建立了该机构的优化设计数学模型 .根据该机构制造、装配与运动特点确定约束条件 ,利用 MATLAB进行优化设计 ,获得了最佳的设计方案     

压板机构的优化设计

本文针对服装整体熨烫机的压板机构进行了分析，并完成该机构的优化设计，机构的优化设计使用了复合形法，采用多级优化技术，得到了满意的结果，为结构设计提供了合理、可靠的数据。     

实现预期轨迹的自动落纱机拔管机构参数优化设计

针对平面连杆机构轨迹再现问题,本文以自主设计的自动落纱机拔管机构上料夹的运动轨迹为例,对实现预期轨迹的自动落纱机拔管机构参数进行优化设计。参考人手拔管过程中纱管所处的多个位置,对纱管夹紧装置中料夹的运动轨迹进行路径规划。同时,以机构实际轨迹与预期轨迹距离之差的平方和为目标函数,调用Matlab中的有约束最小化函数fmincon,求解得到双摇杆机构各参数的最优解,并根据得到的最优机构参数,在Adams中建立拔管机构仿真模型进行轨迹仿真。仿真结果表明,经过优化的机构,其实现的轨迹与预期轨迹基本一致,即拔管时,料夹的轨迹与人工拔管的轨迹基本相同,满足拔管机构工作过程中不得与落纱机其他装置干涉的要求,满足预期设计要求。该研究在我国纺织领域具有广阔的应用前景。     

基于ADAMS的横封机构冲击力分析及其优化设计

根据包装机横封机构的特点,利用ADAMS软件建立了简化的参数化模型,并通过设置目标函数与约束条件,对机构的冲击力这一关键因素进行了分析优化,从而得出最佳设计方案。     

汽车动态仿真器运动机构的优化设计

运用综合约束函数双下降法探讨了六自由度仿真器运动机构的优化设计，并得到六个作动器的最优安装位置及各自由度的极限运动范围。     

基于三角形原理放大机构的设计和有限元分析

针对叠层压电陶瓷输出位移小,不能满足微驱动领域行程要求的问题,提出了一种采用三角形原理的放大机构。并对设计的三角形原理放大机构进行了理论放大倍数的计算,利用有限元分析法对放大机构进行了静力学和动力学分析,得到了三角形原理放大机构的应力分析云图和模态分析云图,验证了设计的合理性。     

压电陶瓷选针机构及其驱动电路的设计

介绍了压电陶瓷电子提花机的特点和设计制造中的难点。在阐明压电陶瓷特性的基础上,结合电子提花机的实际要求,设计了压电陶瓷片作制动元件的选针机构。通过对驱动电路的工作原理的论证,完成相适应的驱动电路设计。设计原理和结构的可靠性已通过样机试运行证实。     

尺蠖型压电旋转驱动器的静动态特性研究

提出一种以压电叠堆为动力转换元件基于尺蠖驱动机理的精密旋转驱动器方案,驱动器定子上的传动单元均采用直角柔性铰链,对柔性铰链力学特性进行了分析,并建立了柔性铰链空间力学模型.对驱动器工作原理进行了分析,采用MSC Patran/Nastran软件对机械结构进行了仿真分析;并对所开发的驱动器样机进行了实验测试.测试结果与理论分析结果基本相符,所开发的驱动器样机具有定位精度高(单步绝对误差率<2%),性能稳定、可靠等优点,可望在超精密加工、精密光学等领域得到应用.     

Development of XY scanner with minimized coupling motions for high-speed atomic force microscope

The design and fabrication processes of a novel scanner with minimized coupling motions for a high-speed atomic force microscope (AFM) were addressed. An appropriate design modification was proposed through the analyses of the dynamic characteristics of existing linear motion stages using a dynamic analysis program, Recurdyn. Because the scanning speed of each direction may differ, the linear motion stage for a high-speed scanner was designed to have different resonance frequencies for the modes, with one dominant displacement in the desired directions. This objective was achieved by using one-direction flexure mechanisms for each direction and mounting one stage for fast motion on the other stage for slow motion. This unsymmetrical configuration separated the frequencies of two vibration modes with one dominant displacement in each desired direction, and hence suppressed the coupling between motions in two directions. A pair of actuators was used for each axis to decrease the crosstalk between the two motions and give a sufficient force to actuate the slow motion stage, which carried the fast motion stage. A lossy material, such as grease, was inserted into the flexure hinge to suppress vibration problems that occurred when using an input triangular waveform. With these design modifications and the vibration suppression method, a novel scanner with a scanning speed greater than 20 Hz is achieved.     

Optimal design of dynamic and control performance for planar manipulator

k]A design and optimization approach of dynamic and control performance for a two-DOF planar manipulator was proposed. After the kinematic and dynamic analysis, several advantages of the mechanism were illustrated, which made it possible to obtain good dynamic and control performances just through mechanism optimization. Based on the idea of design for control (DFC), a novel kind of multi-objective optimization model was proposed. There were three optimization objectives: the index of inertia, the index describing the dynamic coupling effects and the global condition number. Other indexes to characterize the designing requirements such as the velocity of end-effector, the workspace size, and the first mode natural frequency were regarded as the constraints. The cross-section area and length of the linkages were chosen as the design variables. NSGA-II algorithm was introduced to solve this complex multi-objective optimization problem. Additional criteria from engineering experience were incorporated into the selecting of final parameters among the obtained Pareto solution sets. Finally, experiments were performed to validate the linear dynamic structure and control performances of the optimized mechanisms. A new expression for measuring the dynamic coupling degree with clear physical meaning was proposed. The results show that the optimized mechanism has an approximate decoupled dynamics structure, and each active joint can be regarded as a linear SISO system. The control performances of the linear and nonlinear controllers were also compared. It can be concluded that the optimized mechanism can achieve good control performance only using a linear controller.     

Simulation optimal design of a compliant mechanism with circular notch flexure hinges based on the equivalent beam methodology

This paper presents an in-depth study of Equivalent beam model (EBM).Firstly three-dimensional (3D) finite element analysis (FEA) model for circular flexure hinge developed by Zettl et al.was verified by the comparison with Smith’s experimental results and the 3D FEA model was feasible within 5.5% error.Then the accuracy of Timoshenko short-beam due to shear force was verified based on finite element method.The results showed that the EBM has good accuracy within 5% error for 1≤r/t≤3.Finally the EBM methodology was applied for the simulation optimal design of a bridge-type compliant mechanism.The results showed that the EBM methodology has very high numerical efficiency and satisfactory accuracy for simulation optimal design of planar compliant mechanism with flexure hinges.     

Dynamic substructure model for multiple impact responses of micro/nano piezoelectric precision drive system

A dynamic substructure technique which considers the electromechanical coupling effect of the PZT and the inertial effect of flexible components is presented to study the multiple impact dynamic be- havior of micro/nano piezoelectric impact drive systems. It can investigate the step-like motion of ob- ject body and the multiple impacts behaviors reasonably by the comparison of the experimental data and the numerical solution of the spring-mass model. It is expected to have higher accuracy in the numerical s...     

盾构管片拼装机举升机构优化设计

分析了管片拼装机垂直升降油缸举升机构和平行四边形举升机构的异同,得出采用平行四边形举升机构在空间的布置以及结构性能方面都优于采用垂直升降油缸举升机构。通过对管片拼装机的平行四边形举升机构进行建模分析,并采用MATLAB优化工具箱对平行四边形举升机构进行优化设计,对比优化前后液压油缸受力曲线,得出优化后的液压油缸受力明显小于优化前。     

FAST中的宏/微机器人概念及索张力的优化配置

基于大射电望远镜ＦＡＳＴ创新设计中悬索与Ｓｔｅｗａｒｔ平台两级调节方案,提出了并联宏－微机器人的概念,建立了悬索柔性机器人的系统的逆运动学模型;针对悬索柔性的特点,在满足馈源电性能要求的前提下,提出了索系结构张力配置的优化方案,计算结果表明该方案可使悬索张力的分布更加均匀,并可避免悬虚牵,这一方案也可用于其他并联悬索结构的张力配置。     

改进蚁群算法在并联六自由度平台优化设计中的应用

蚁群算法在解决组合优化问题上有着良好的适应性,但直接应用于求解连续优化问题难以获得理想的效果．通过对蚁群算法中的全局搜索、局部搜索以及信息素更新规则等环节进行有效的改进,构成了可用于连续优化问题求解的改进蚁群算法．将该算法应用于以灵巧度为目标函数的并联六自由度平台结构设计问题中,通过与采用基本蚁群算法得到的优化结果进行比较,证实了改进蚁群算法具有较好的全局优化能力和较快的收敛速度,可以有效求解并联六自由度平台结构设计这一类连续优化问题．     

Research on critical technology of micro/nano bioparticles manipulation platform based on light-induced dielectrophoresis

On the basis of the research on the status and problems of micro/nano bio-particles manipulation using dielectrophoresis, the theoretical basis and the model simulation of micro/nano bio-particles manipu-lation using light-induced dielectrophoresis were discussed. The space distribution of electric field and dielectrophoresis forces in different heights were also obtained. On this basis, the core component of the micro manipulation system, that is, photoconductive layer of the chip, was completed in the mat...