Calibration of Space Robot Parameters Based on Base Coordinate System Errors

Abstract

A motion error parameter identification method is proposed to address the issue of insufficient absolute positioning accuracy of a seven-degree-of-freedom space robot based on the geometric parameter errors of the robotic arm and the position errors of the base coordinate system. Firstly, the kinematic model of the space robot is established based on a modified complete and parametrically continuous model, and the mapping relationship between the geometric parameter error of the robotic arm link and the end-effector pose error is obtained using the pose differential transformation method. Then, taking into account the base coordinate system's positional error, a novel model for the space robot is developed, based on the errors associated with the base coordinate system. Finally, the identification of kinematic parameters is accomplished using the Levenberg-Marquardt optimization algorithm. Simulation results validate the effectiveness of the proposed method.