Design for Robust Controls Having Almost Minimum Time Response

The problem of proximate time-optimal control of third-order systems is considered. Two third-order proximate time-optimal servomechanisms, PTOS3 and PTOS3¿, are proposed for type-3 and type-2 third-order plants, respectively. The approach used here to develop the controllers is that of constructing a ´slab´ in 3-dimensional state space that describes the ´switching´ structure of the control. The technique relies on 3-dimensional phase-space analysis which is rarely applied to systems of order 3 or higher. Simulation results demonstrate the performance of the developed algorithms.