Dual-rate global digital redesign for flight control

This paper proposes a dual-rate global digital redesign method for the design of flight control systems. Given a two-loop continuous-time autopilot, dual-rate digital redesign based on the concept of plant-input-mapping is applied at each operating point. The proposed approach allows to constrain the orders of the discrete-time controllers, which is a significant consideration when gain scheduling of the linear control laws is performed over the flight envelope. The dual-rate digital redesign technique provides satisfactory closed-loop performances over an extended range of sampling rates, as compared with other widely used methods of digital redesign. Numerical simulations of a symmetrical, tail-controlled missile demonstrate the effectiveness of the proposed method.