Minimal time control of a discrete system with a nonlinear plant

This paper treats the problem of minimal time control of a class of pulse-width-modulated (PWM) regulator systems with plants described by a nonlinear second-order differential equation. For the type of nonlinearity considered, it is found possible to carry out the necessary phase plane constructions by making use of the geometric properties of the solutions of the plant differential equation. The resulting optimal strategy is quite simple and is similar to the one for PWM systems with linear second-order plants whose transfer functions have nonpositive poles and no finite zeros [3].