Finite-Time Intermittent-Update Control for Aircraft Electric Antiskid Braking System via Sliding Mode Approach

In order to achieve optimal slip ratio tracking, this article proposes a sliding mode intermittent-update control (SMIC) method for the aircraft electric antiskid braking system. Based on analyzing the aircraft braking process and the electromechanical characteristics of actuators, a comprehensive model is established, incorporating slip ratio, braking pressure, and rotor angular velocity in a cascade structure. Due to the complex runway environment and diverse climate conditions, the inherent variability and nonlinearity of the optimal slip ratio pose significant challenges to the sustained utilization of maximum friction. To address the above challenges and enhance braking performance, a switching extremum search approach is proposed to optimize the slip ratio in real time. A sliding mode intermittent-update controller is designed to track the real-time optimal slip ratio, ensuring finite-time convergence and effectively preventing wheel slip and lock-up. Finally, the proposed control strategy is validated on a realtime hardware-in-the-loop-based platform, which demonstrates that the SMIC strategy can not only effectively improve the braking efficiency but also reduces the switching frequency of the electromechanical actuators.