Error modeling and identification of a parallel robot in a hybrid machine for polishing

Abstract

In this paper, a novel hybrid machine for ultra-precision polishing is presented. It mainly composes of a 3-DOF parallel robot, a 2-DOF serial robot and a turntable providing a redundant DOF. The error model of the parallel robot is studied based on the D-H conventions which gives an explicit relationship between the moving platform's pose errors and the component's geometric errors. Based on the principle of minimizing the maximum absolute value of the residual equation, an error identification model of the parallel robot is established. The group search algorithm is used to solve the identification model, which provides the basis for the following error compensation.