Fuzzy Shared Control Method and Automatic Assistance for Aircraft Under Pilot-Induced Oscillations

This paper presents a new human-machine shared control method to improve the control performance of the aircraft in abnormal situations. To solve the problem of Pilot-Induced Oscillations(PIO) caused by elevator rate limitation, a shared control method based on autopilot assistance is designed by adjusting the gain of the pilot's control command. This method takes advantage of the precision control of the autopilot and corrects the pilot's excessive control behavior, thereby enhancing the stability of the aircraft in complex environments. The key feature of the proposed shared control is that it utilizes the control command of the autopilot to achieve the process of assisting the pilot in flying, which helps reduce the pilot's high control gain while keeping the elevator away from saturation. At the same time, considering the fact that the pilot's instantaneous judgment of triggering a fault has certain ambiguity, the pilot's adaptive logic trigger module is utilized with fuzzy logic. Finally, the effectiveness of the shared controller is verified by the experimental simulation of F-16 longitudinal dynamics under abnormal conditions.