TRAPEZOIDAL PULSE-WIDTH-MODULATION CONTROL OF NONLINEAR MECHANICAL SYSTEMS

A pulsed feedback control strategy is proposed for the robust stabiliz ation of a class of multivariable mechanical systems in which rate con strained angular, or linear, velocity variables are regarded as contro l inputs. The trapezoidal character of the pulsed-width regulation pol icy complies with the physical limitation of having corresponding acce leration variables; i.e., applied torques, or forces, of bounded magni tude. This practical limitation would be clearly violated in the tradi tional mathematical formulation of (discontinuous) pulse-width-modulat ion control schemes using rectangular (velocity) control input pulses. The proposed approach is used in the approximate feedback control reg ulation of both a multivariable differentially flat system and also of a high frequency controlled non-differentially flat system.