2018 年 54 巻 2 号 p. 194-200
This paper is concerned with a control problem for linear systems by means of pulse-width-modulation (PWM)-type input. Since the PWM input system is nonlinear in terms of the duty ratio, its analysis and design for precision control is in general difficult. Nevertheless it turns out that the discrete-time systems on the sampling instants can be exactly transformed to single input linear systems by making the number and center-locations of pulses variable, where the fact that the sets of the vector-values of the input terms are convex is used. In this paper, by utilizing the above fact further, we propose a method exactly transforming the nonlinear discrete-time systems to multi-input linear systems.