ERROR MODELLING AND DIFFERENTIAL-EVOLUTION-BASED PARAMETER IDENTIFICATION METHOD FOR REDUNDANT HYBRID ROBOT

Abstract

AbstractThis paper focuses on the geometrical error modelling and parameter identification of a 10 degree-of-freedom (DOF) redundant serial—parallel hybrid intersector welding/cutting robot (IWR). The proposed hybrid robot consists of a kinematically redundant 4-DOF serial mechanism to enlarge workspace and a 6-DOF Stewart parallel robot to improve the end-effector accuracy. Due to its redundant degrees of freedom and the serial—parallel structure, the traditional error modelling and identification methods which tailored for pure serial robot or pure parallel robot cannot be directly used. In this paper, a hybrid error modelling method for redundant serial—parallel hybrid robot is presented by combining both the traditional forward calibration and inverse calibration method. Furthermore, because of the high nonlinear and multi-modal characteristics of the derived hybrid error model, the traditional iterative linear least-square algorithm cannot be utilized to identify the error parameters. In this paper, ...