Inverse scaled four channel control system with wave variables under time delay

Wave variables approach is mostly used due to its conservation to keeping passivity in time delayed teleoperation. On the other hand, excess conservation of passivity results in degraded system performance on environment perception or positional maneuverability. In physical environments waves are reflected, diffracted and refracted. Thus, wave variables approach introduces drifting problem to control systems. Performance improvement of time delayed control systems is carried out by introducing four channel control structure which transmits both of the position and force information to the master and slave robots by using wave variables. The bandwidth of environment perception is highly improved by wave variables data transmission and reaction force observer based sensorless force observation. Additionally, inverse scaling of control data in master and slave robots makes it possible to consider the drift problem which is caused by wave reflections, not only in damping terms but also in mass terms. In other words, acceleration dimension is directly introduced into the wave variables approach as well as the same dimension is used in overall control structure. Real time experiments are carried out to show the validity of our approach.