Real-time control experiments using an industrial robot retrofitted with an open-structure controller

A robotic testbed has been developed in our laboratory by retrofitting a PUMA 560 industrial robot with a custom-built controller. The main objective of the testbed is to provide researchers with a robot control system possessing an open hardware structure, high computational capacity, and good software programmability, such that various advanced control schemes intended for robots can be implemented in real-time and evaluated through physical experiments rather than simulation. On this testbed, different control schemes including regressor based adaptive control of the robot performing tracking tasks are implemented. Dynamics of robot actuators are incorporated in the experiments. The performance of these control schemes is quantitatively evaluated. For comparison purposes, a conventional PD controller is also implemented independently in each joint of the robot. This paper outlines the hardware configuration and software support of the testbed. Adaptive control scheme incorporating actuator dynamics is described and experimental results are presented. These experiments show that advanced control schemes can be effectively used to improve the performance of an industrial robot in a significant manner