State Feedback Fuzzy Adaptive Control for Active Shimmy Damping

In the context of aircraft, shimmy is an oscillatory phenomenon of the landing gear mainly due to the tire and the landing gear structural dynamics. This phenomenon which can result in severe damage to the landing gear must be damped. This paper presents a new nose landing gear model including an actuator model and a simple tire/road interface description approximating the Pacejka model to allow the active damping of the shimmy phenomenon. Two state feedback control solutions, based on indirect and direct fuzzy adaptive theories, are also presented and compared with a more classic Proportional Integral Derivative (PID) solution. Results corresponding to different test scenarios and robustness analysis show that the proposed controllers are able to efficiently damp the shimmy phenomenon, unlike the PID controller.