Wave-Echo Control of Lumped Flexible Systems

An elegant, generic solution is presented to the problem of point-to-point control by a single actuator of a remote load through an intermediate flexible system, modelled by a system of lumped masses and springs. It is based on new ways of looking at the problem that respect and exploit the underlying dynamics. Under wide-ranging conditions the strategy allows rapid, almost-vibrationless, precise position control of the load, independently of the order of the system, without the need for a detailed system model or ideal actuator. During the start-up, the system itself reveals to the controller how to terminate the motion, so that the real system also acts as the model for the controller. The scheme is very robust to modelling, actuator and sensor errors. The strategy is presented, with some of the motivating ideas reviewed.