Vibration Characteristics of Landing Gear Walk Caused by Aircraft Anti-skid Brake

Aircraft anti-skid brake which is usually installed on the wheels of the main landing gear of aircraft, is a key subsystem to ensure the safety of aircraft takeoff and landing. At the state of aircraft taxiing, the anti-skid braking system will cause the landing gear vibrating forward and backward along the aircraft speed direction, such low frequency vibration is also called walking. This paper established the model of aircraft braking system with the help of MATLAB/Simulink software, the data interaction between the model and the multi-body dynamic model of landing gear is conducted through the joint simulation interface, the walking characteristics is then studied. In order to study the vibration influence of the anti-skid control system, a reference rate velocity difference brake control law with bias pressure bias modulated regulation and a slip rate brake control law based on PI were designed respectively. The influence of key control law parameters on walking vibration is then analyzed on dry and wet runways. Simulation results show that for the two different control laws, the influence of proportional stage parameters on walking and braking efficiency is greater than that of integral stage parameters. In addition, the proportional level parameters vary linearly with braking efficiency and buffeting amplitude within a certain range.