一类运动支链逆解问题的旋量指数积求解方法

Solution to inverse kinematics of a type of kinematic chain using screw theory and exponential product method

针对RRSR支链,提出了一类新的子问题:即子问题"绕两平行轴线旋转到指定点的问题"及其扩展子问题"绕两平行轴线旋转后距离两点为指定距离";推导了这类子问题的求解方法.通过将RRSR支链逆解求解转化为该类子问题和一些已知的子问题,给出了该类运动链的逆解的求解过程,并对该支链的多解性问题给予分析,明确了逆解及多解条件的几何意义.最后给出实例计算,验证了求解方法的可行性和正确性.

A new category of sub-problems is proposed for the RRSR chain. They can be described as ＂rotating about two parallel axes to a given point＂ and the extended subproblem ＂rotating sequentially about two parallel axes to a point at the same distance to two given points＂. And the solution of these two subproblems is derived. After converting the inverse kinematics of the RRSR chain into several sub-problems, the solution procedures are presented. The multi-solutions are analyzed and the geometric meanings are explained. And the feasibility of this method is validated through an instance with exact parameters.