Nonlinear Autopilot Design for Agile Interceptors via Command Filtered Backstepping and Dynamic Control Allocation

For agile interceptors with aerodynamic control surfaces and reaction jets, a nonlinear autopilot design method is proposed by using command filtered backstepping and dynamic control allocation algorithm. Since there are two different types of actuators, it is necessary to consider collaboration issues. Therefore, the autopilot involves a nonlinear virtual control law and a dynamic control allocator. To deal with parameter uncertainties and unknown disturbances in the system, a robust virtual control law is designed by command filtered backstepping. Then, a dynamic control allocator is applied by optimal programming to distribute the virtual signals to the aerodynamic control surfaces and reaction jets on the interceptor. Simulation results show that the autopilot control system tracks the acceleration command fast and smoothly. In the tracking process, aerodynamic control surfaces cooperate with reaction jets, verifying the effectiveness of the proposed design method.