平面五杆并联机构优化的自重构方法

并联机构机械臂具有工作空间小、运动学和动力学运动特性复杂的缺点。基于优化技术，各种并联机器人运动综合技术只能相对地提高机械臂的运动性能，不能保证一定能得到满足实际要求的设计结果。本文提出了机构的动态重构思想，并以五杆并联机械臂为具体对象，研究了机构运动学各向同性的最优综合设计问题，指出可重构并联机构的两种运动阶段：正常运动阶段和机构重构运动阶段，这两个运动阶段可以采用统一的运动性能评价方法进行研究，从理论和方法上指出了一条从本质上提高并联机构运动性能的方法，以平面五杆并联机构为对象给出了计算实例和具体方法。

Optimization of Planar Five-bar Parallel Mechanism via Self-reconfiguration Method

The parallel mechanisms have the disadvantage of small workspace and complication in kinematics and dynamics. An optimizing design for the parallel mechanisms can improve the motion performance relatively, but not guarantee the design results which satisfy the various practical requirements simultaneously. In this paper, a dynamical and optimal synthesis method is proposed for parallel mechanisms based on the dynamical reconfiguration technique. As a specific, application, the problem of optimizing the kinematics isotropy of a five-bar planar parallel mechanism is studied. The motion of a reconfigurable mechanism can be parted into two phases, the natural motion phase and the reconfiguration phase. The two motion phases can be studied by the same performance evaluation methodology. This points out from both theory and practices a novel method for improving the motion performance of the parallel mechanisms. Simulation by a symmetrical five-bar planar parallel manipulator shows some aspects of the investigations.