A general approach for accuracy analysis of parallel manipulators with joint clearance

Due to the joint clearance, parallel manipulators always exhibit some position and orientation errors at the mobile platform. This paper aims to present a novel and general approach for evaluating the maximal pose deviation of the mobile platform under the influence of joint clearance. First, it shows and proves that overconstrained parallel manipulators can not work without clearance. Then, an efficient method is proposed to evaluate the maximal pose errors for general spatial parallel manipulators with joint clearance. A numerical example shows the application and efficiency of the proposed approach.