新颖微型压电旋转关节的建模与仿真

Modeling and Simulation of a Novel Miniature Piezoelectric Rotary Joint

提出一种基于惯性冲击驱动原理的新颖微型压电旋转关节,用于关节臂式多自由度定位操作系统的旋转关节驱动.该旋转关节采用对称的整体结构设计,利用压电堆产生驱动力矩,通过碟形弹簧调整预紧力,具有运行稳定、驱动力矩大、易于微型化等优点.建立了该机构驱动模块的结构模型,运用ANSYS软件分析了定子结构的静态变形和固有振动特性;建立了该机构的动力学模型,应用MATLAB/Simulink软件获得了旋转轴的粘滑运动和步进位移特性.仿真结果表明,该压电旋转关节具有较好的步进位移输出能力和较宽工作频率范围,在1 000 V/mm激励电场下,步进位移达到0.07°,稳定的粘滑工作频率达到1 000 Hz以上.

A novel miniature piezoelectric rotary joint was proposed based on the inertial impact-driving mechanism, which is applied to the multi-DOF articulated positioning and manipulation systems. The ro-tary joint adopts symmetrical design for the whole structure, uses piezoelectric stacks to generate driving torque, regulates pre-pressure with disk springs, and enjoys such advantages as stable operation, large driving torque and easy miniaturization. Structural model of the driving module was established, in which static deformation and natural vibration characteristics of the stator were analyzed with ANSYS software. Dynamic model of the rotary joint was also established, in which stick-slip movement and stepping dis-placement characteristics of the rotary shaft were obtained through MATLAB/Simulink software. The sim-ulation results show that the proposed piezoelectric rotary joint possesses a good stepping displacement output ability and a wide operating frequency range. Under an electric field of 1000 V/mm, a stepping displacement of 0. 07° was achieved, and stable stick-slip operation remained over 1000 Hz.