三支链六自由度并联柔性铰微动机器人的研究

Research on a three-link six-DOF micromanipulator with flexure hinges

提出了一种过程中采用的新型三支链六自由度并联微动机器人结构。采用两端分别带有柔性球铰和柔性旋转铰的支杆以简化结构,整体加工包含三个二自由度单元的基平台来有效减小装配误差,并用压电陶瓷驱动弹性平板获得高分辨率高精度。根据运动影响系数理论对其运动学进行分析,求出了其平动台、支杆和柔性铰链的速度表达式。考虑柔性铰链的弹性变形,基于虚功原理建立了其刚度模型。分析了此类并联微动机器人的设计目标和柔性铰链设计原则,采用模块化精密定位控制器设计了控制系统。实验结果表明,所设计的微动机器人可达到纳米级精度,简化了六支链六自由度并联微动机器人的复杂结构,减小了装配误差。

A three-link six degree-of-freedom （DOF） parallel micromanipulator is presented. Three inextensible limbs with the spherical flexure joints and single-axis rotary flexure joints at the two ends are adopted to simplfy the complex stucture and a monolithic base plate that consists of three 2-DOF compliant units is utilized to reduce the assembly error. The piezoelectric elements are used as the high resolution actuators. The kinematics solutions are analyzed using the kinematic influence coeffi： cient theory, as a result, the velocity of a movable platform, the limbs and the flexure hinges are derived. The stiffness model of the micromanipulator is determined considering the elastic deformations of the flexure hinges based on virtue work principle. The design targets and the design principles are discussed and the precise position controller modules are used to control the micromanipulator. Finally, the primary experiment tests are performed and the results show that the nanometer scale precision is attained.