TIME DELAY COMPENSATION CONTROL STRUCTURE FOR A ROBOTIC TELEOPERATION SYSTEM Cecilia E. García, Ricardo Carelli, José F. Postigo and Beatriz Morales Instituto de Automática Facultad de Ingeniería. Universidad Nacional de San Juan. Av. Libertador San Martín 1109 oeste (5400) San Juan. República Argentina. {cgarcia,rcarelli,jpostigo,bmorales}@inaut.unsj.edu.ar Abstract: In this paper a time delay compensation control structure for a robot teleoperation system is presented. The structure design was made considering 1.9-seconds time delay in the communication between the remote and local stations. The objective is to control both the remote manipulator’s position and force. Force and position signals are fedback to the local station so that the human operator feels in his/her hand the force associated with the task being executed at the remote site. Simulations are carried out considering the dynamic model of the human operator in the control loop. In this sense, simulations show a good performance of the proposed compensation control structure. Keywords: Teleoperation, Automatic Control, Telerobotic, Position-Force Control, Time delay compensation. 1. INTRODUCTION In robot teleoperation processes, the human operator applies an intentional force on the local manipulator generating a series of commands to be applied on the remote station. To generate the intentional force, the operator needs several signals to be sensed in the remote station and given by a visual display on a monitor as bar graphs, which represent the reflected force on the local arm. Then, the operator can generate the desired command according to the task that he/she should carry out. The success of a teleoperation task depends both on the quality of the signals fedback from the remote site and on the correct reception of them by the human operator, and also depends upon the generation of his/her appropriate force/position intentional command (Lee, 1993). The continuous teleoperation in earth orbit or deep space performed by a human operator from earth is seriously affected by several problems, as: transmission time delays, limits on the radio transmission bandwidth, computer signal processing at sending and receiving stations and satellite relay station. A similar problem is found when remote controlling in deep ocean applications, if acoustic telemetry is employed to avoid dragging miles of heavy cable (Sheridan, 1993). Given a finite time delay in a continuous telemanipulation loop, many experiments have demonstrated how the elapsed time for a human operator to accomplish even a simple manipulation is a significant function of the delay, the task complexity, and the manipulation control scheme. Ferrel (1965) first proved conclusively that the human operator, in order to avoid instability, can adapt what has come to be called a “move and wait strategy”. In this type of strategy, the operator makes a discrete control motion, then stop while waiting (the round-trip delay time) for confirmation that the control action has been followed by the remote manipulator or vehicle, then makes another discrete movement, and son on