Wave-echo position control of flexible systems: towards an explanation and theory

An elegant, novel solution has been developed to the general problem of point-to-point control by a single actuator of a remote load through an intermediate flexible system. It is based on mechanical wave concepts. Under wide-ranging conditions it allows almost "perfect", vibrationless motion of the load. It requires minimal knowledge of the system dynamics and is robust to changes in load, to non-ideal actuator behaviour and to sensing errors. Transit times are excellent. In the start-up the system itself reveals to the controller how to terminate the motion, so that the real system acts as the controller model. In developing the strategy practice has preceded theory. This work presents and explores theoretical explanations of the success of the method.