Abstract:

The industrial robot has been widely used in industrial fields such as stacking, handling and welding because of its high repeatability. But its absolute positioning accuracy is poor, which limits its application in the fields of high precision manufacturing. By building an industrial robot errors measurement and online compensation closed-loop control system, the errors of the industrial robot are compensated on-line. This method takes into account the errors caused by geometric and non geometric parameters, and improves the position and attitude accuracy. The performances of position and attitude errors compensation based on the KUKA Robot Sensor Interface are studied. By studying the representation of the end attitude of the KUKA robot, a method is put forward to measure the attitude of the industrial robot based on laser tracker and the characteristics of the position and attitude errors of the robot in its workspace are studied experimentally. The position and attitude compensation effect of the closed-loop control system is verified by experiments. The experimental results show that the absolute positioning accuracy is improved from 0.628 mm to 0.087 mm and the attitude accuracy is close to 0.01° after the second online errors compensation.

Key words: laser tracker, online errors compensation, position and attitude accuracy, industrial robot