Accuracy Analysis of Parallel Manipulators With Joint Clearance

Due to joint clearance, a parallel manipulator's end-effector exhibits position and orientation ( or collectively referred to as pose) errors of various degrees. This paper aims to provide a systematic study of the error analysis problem for a general parallel manipulator influenced by joint clearance. We propose an error prediction model that is applicable to planar or spatial parallel manipulators that are either overconstrained or non-overconstrained. By formulating the problem as a standard convex optimization problem, the maximal pose error in a prescribed workspace can be efficiently computed. We present several numerical examples to show the applicability and the efficiency of the proposed method. [DOI: 10.1115/1.3042150]