Abstract:
The phase lag and amplitude between the input and the output decrease when the rate limiter is saturated. Based on the model predictive control (MPC) method, a controller is designed to convert the rate-limiting condition into the system input constraint, allowing it to prevent category Ⅱ pilot-induced oscillations (PIOs) caused by the saturation of the rate limiter. The effects of the controller on the system phase are analyzed with sine input signals and the controller is applied to a pilot-aircraft closed loop system to carry out the simulation. The simulation results show that the MPC controller causes a phase lead. It can help the pilot eliminate the system error before PIOs occur, fully overcome the effects of the rate-limiter under the occurring condition, and prevent PIOs effectively.