Repetitive control of robot manipulators using only position measurements

This paper presents a repetitive leaning control in the discrete time domain. A design method as well as stability conditions is given based on the concept of strictly positive realness. Using the proposed method, a repetitive tracking control system for robot manipulators arc developed which requires only position feedback and has a very simple structure. The performance of the system is illustrated with a two-link manipulator. In spite of the high nonlinearity of the robot dynamics, a simulation result shows that the position tracking error can be reduced exponentially.