Trajectory Control of an Industrial Robot (4th Report)

Industrial robots have been applied in many fields. So far, these robots have been controlled by the ”Point to Point” or ”Continuous Path” control methods. Generally, industrial robots are non-linear, multivariable, time-varying systems and when the robot is moving, an interaction between the arms exists. Therefore, we try to decouple the system using the decouple control theory. At this time, the feedback law permits an arbitrary assignment of a specified number of poles. Next we compose a servo-system for the decoupled system. In computer simulations, an error of output between the robot system and the decoupled system occurred. Therefore, we add the PI action to the system in order to compensate for errors between the output of the robot system and a reference trajectory. When the robot is in motion, parameters of the robot are changing because of load fluctuation and so on. In this case, it isn't always controlled well by using the fixed prameters control methods. Therefore, an application of the model reference adaptive control method to the robot system was investigated. As the results of computer simulations, the robot arms follow well the reference trajectory in spite of the load fluctuation, and the availability of the proposed control methods was confirmed.