An Approach to Determine All Joint Motions of Parallel Robot and Its Software Development

Abstract

Inverse kinematics for all joint motions of parallel robot is the foundation for stiffness or dynamic analysis, and the prerequisite for motion monitoring during operation in case of collision or damage. The software equipped with a generalized inverse kinematic method is beneficial for the efficient motion solving of different parallel robots, and especially convenient for kinematic control development. Current inverse kinematic methods are either case-by-case studies or not amicable for programming. To tackle these problems, this paper proposes a generalized method to determine all the joint motions of parallel robot based on finite screw theory, including mechanism initialization, kinematic modeling and kinematic variable solving. Two parallel robots are taken as examples to verify the effectiveness and accuracy of the approach. After that, the method is applied for digital programming on the basis of computer technology, and a software is developed for the automatic inverse kinematic analysis. The advantages of this method lie in: the kinematic equation could be formulated in a general and concise manner independence of experience and observation; all the joint variables under given target pose are solved at the same time; it enables easy programming and realizes the automation of inverse kinematic analysis.