An application of the 4-parameter controller to the robot payload variation problem

The authors describe the design of a diagnostic system to maintain high performance of robotic manipulators in the face of payload variations. The novel application of failure diagnostic methods to the problem of detecting abrupt payload variations in robots is introduced. Application of the four-parameter controller to the simultaneous design of the feedback control and diagnostic systems using a computed torque controller is based on the key concept of treating the study of payload variations as a failure diagnostic problem. The proposed methodology has been tested on a PUMA-560 robot arm in a three-degrees-of-freedom configuration. The simulation results obtained demonstrate the promise of the methodology