Method for Modifying Taught Data for Accurate High Speed Positioning of Robot Arm

摘要

This paper describes method for modifying taught data for robot arm, aiming at accurate high speed positioning. For industrial teaching/playback type robots, objective trajectory data has been usually used as taught data which are the input for teaching/playback type robots. In the conventional method, deteriorations of the control performance, such as time delay of robot arm motion and deviation among composed axes occur. Therefore, we propose a method for modifying taught data, which, is designed using the pole placement method through state space description of robot arm control system. By using the proposed method, we can easily calculate the modified taught data. The characteristics of the robot arm performance which is controlled by using the proposed method, are analyzed in the time domain and in the frequency, domain, respectively. The effectiveness of the method for modifying taught data is shown by the experimental results of analogue computer which faithfully simulated actual robot arm equipment. Experiments for positioning were made by the conventional method and the proposed method for objective trajectories of rectangular line and circle, respectively. The experimental results show that the proposed method is far more accurately tracking the objective trajectory compared with the results of the conventional method. The method for modifying taught data can be applied to the robotarm control problem without any changes of hardware of the robot arm system and this method can be used to any objective trajectories of the robot arm. This method can be applied not only for robot arm control but also for other mechanical control and plant control. Therefore the proposed modification of taught data is very useful to engineering and industrial application.