Anti-Windup Command Filtered Adaptive Backstepping Autopilot Design for a Tail-Controlled Air-Defense Missile

Two missile autopilots based on Command Filtered Adaptive Backstepping (CFAB) are developed for a tail-controlled missile, which is steered in Skid-To-Turn (STT) mode. First, a standard CFAB approach is tailored to the missile application. The second control law constitutes a modification of standard CFAB design by incorporating an anti-windup strategy. This novel Anti-Windup CFAB (AWCFAB) control law accounts explicitly for the limitations of the actuator dynamics in order to prevent anti-windup effects. Since the missile dynamics is subject to a large spectrum of uncertainties, an adaptive control layer is needed, which compensates for the main disturbances, uncertainties and modeling errors. Therefore, the desired, nominal performance and tracking quality can be preserved even in cases of a degraded plant model. Two evaluation series are accomplished with a high-fidelity 6DOF missile model, in which a realistic spectrum of uncertainty combinations and actuator limitations are considered. In the first evaluation series the performance of standard CFAB and the developed AWCFAB autopilot is compared under nominal conditions. For this purpose a demanding Skid-To-Turn scenario is chosen, which requires the full actuator capability. The benefits of the adaptive autopilot are demonstrated via Monte-Carlo simulations.