关键词: 工业机器人, 分级补偿, 重力参数, 运动学参数模型, 柔度误差

Abstract: Combining kinematics error and flexible errors,a hierarchical compensation strategy for robot operation errors was proposed to achieve precise positional control in machining tasks.Based on the traditional calibration method of geometric parameter errors,a robot kinematics parameter error model coupled with gravity parameters was established to achieve offline correction of robot control commands.Aiming at the poor accuracy of robot stiffness caused by the fixed value assumption of joint stiffness,a variable stiffness identification method was proposed on the basis of space gridding,and online prediction of flexible errors caused by loads was achieved through online collection of operating load.The validity of the hierarchical compensation method was verified by the positional error compensation experiment of discrete position under operation load.The experimental results showed that the proposed method could improve the robot positional accuracy under load to 0.217 mm,which had significant theoretical significance and engineering application value.

Key words: industrial robot, hierarchical compensation, gravity parameters, kinematics error model, flexibility error