Nonlinear Robust Anti-Windup Control Design base on Precise Feedback Linearization

For the control system of the hypersonic vehicle longitudinal dynamics model, an anti-saturation controller is implemented when the control input is over-saturated for a strong disturbance. To solve the tracking control problem of nonlinear systems with disturbance under control constraints, an anti-saturation robust controller based on feedback linearization is proposed. First, the nonlinear mathematic model is linearized via exact feedback linearization, and then the closed-loop gain designed by the robust control algorithm to tracking control with disturbance. According to the robust control theory, the better the anti-disturbance performance of the designed robust controller is, the easier the actuator will enter the over-saturation state when the aircraft is under strong disturbance. To solve this problem, an anti-saturation compensation element is designed by using the gain matrix feedback anti-saturation theory. When the actuator exceeds the saturation boundary, the compensator will modify the control output. Simulation analysis shows that the flight control system with the additional anti-saturation element can restrain the actuator over-saturation and improve the control capability under large disturbance.