Research on the Follow-Up Braking Control of the Aircraft Engine-Off Taxi Towing System Under Complex Conditions

The traditional ground taxiing method of aircraft has the drawbacks of low efficiency and excessive fuel consumption. In this paper, an aircraft engine-off taxi towing system (AEOTTS) is proposed to provide high-speed traction for the aircraft throughout the entire ground movement. This will be a more efficient intelligent taxiing mode for aircraft. However, the new braking control strategy for the AEOTTS under complex conditions is not yet mature. Based on the motion and mechanical symmetry of the AEOTTS and combined with the contact model of the pick-up and holding system (PUHS), a coupling dynamic model of the AEOTTS is established. On this basis, a state estimator of the AEOTTS is established using the unambiguous Kalman filtering (UKF) method. The follow-up braking control system of the AEOTTS is constructed with the goal of minimizing the towing force on the aircraft’s nose landing gear (NLG), combined with the optimization of braking force distribution and the fuzzy PID control method. By comparing the braking performance of three follow-up braking control systems under wet runway conditions and runway unevenness conditions, the results show that compared with the other two control methods, the follow-up braking control system proposed in this paper can effectively reduce the towing force on the aircraft’s NLG and the braking distance of the AEOTTS, ensuring the safety of the taxiing and traction braking process.