A constructive predictor-corrector algorithm for the direct position kinematics problem for a general 6-6 Stewart platform

This paper deals with the direct position kinematics of a general 6-6 Stewart platform and presents a new and efficient algorithm to solve the problem. Unlike the convention of developing a set of kinematic equations and then solving them, an alternative approach is proposed which involves just a search and verification purely from geometric considerations. An attempt at conceptual construction of the mechanism under given constraints results in the prediction of tentative solutions, which are subsequently corrected. The algorithm is implemented and two case studies are reported. The proposed algorithm is simple to implement, finds all the real closures and is applicable to the most general case of the Stewart platform