Command filter based active fault tolerant control of missiles intercepting maneuvering target

This paper presents a command filtered based active fault-detection and correction scheme for integrated guidance and control (IGC) of a supersonic skid-to-turn interceptor. It utilizes global terminal sliding mode (GTSMC), command filter, backstepping control, and extended state observer (ESO). The IGC technique accounts for the delay dynamics of the actuator subsystem and addresses constraints related to the impact angle. A strict-feedback IGC model is developed, including delayed rudder dynamics. Fault detection and estimation observers are designed to detect the presence and magnitude of faults in the rudder subsystem. The backstepping-based guidance and fault-tolerant control system comprises guidance, attitude, normal overload, and rudder subsystem. The guiding subsystem uses GTSMC to facilitate rapid convergence of the impact angle. The ESO effectively measures and compensates for lumped disturbances with target maneuver, external disturbances, and aerodynamic parameters. The stability of the IGC system is proven, and simulation results show superior performance compared to existing methods.