Attitude control for hypersonic vehicle´s reentry phase with reaction jets

In this paper, a new method is proposed for the design of control laws for hypersonic vehicle flying at the beginning part of the reentry phase with reaction jets, where magnitude of control input is fixed but pulse width is adjustable. A robust anti-saturation control law for continuous-time system is designed to resist model uncertainty and avoid saturation in pulse-width modulation (PWM) control system. The continuous-time control law guarantees H8 performance indexes constraint and quadratic performance indexes constraint at the same time. Discrete-time state feedback control gains are obtained from the digital redesign of continuous-time feedback gains, and a PWM controller is developed based on the equivalence of PWM control systems and discrete-time control systems. The effectiveness of the method is illustrated through numerical simulations.