Robust reconfigurable control law design with actuator saturation

In order to solve the robustness problem of regular explicit nonlinear dynamic inversion (NDI) control law, the robust NDI control law was designed via implicit dynamic inversion (DI) and singular perturbation methods, in which the state speed (derivative) and the current actuator position were fed back, and the whole aerodynamic model was unnecessary, and as a result, the sensitivity to aircraft model was decreased. The angular acceleration was established utilizing a special geometrical method through overloading information, and the other state speed was obtained based on the aircraft dynamic equations. The rate/position saturation was reduced by using adaptive weighting matrices and the multi-pass allocator solution. The control structure was simple, and the isolation of measurement signals, reestablishing of feedback signal, re-allocation of control power and the reconfiguration of control law can be achieved conveniently and rapidly. The control law design and computer simulation using a high precision aircraft model with aerodynamic perturbation, external disturbance and nonlinear actuator demonstrate that the robustness of the control law is increased.