RBF-based backstepping control of semi-active landing gear system with solenoid valve actuator

In this paper, we present a RBF-based backstepping scheme for the semi-active control of landing gear system using high speed solenoid valve actuator. The full dynamics of a novel semi-active shock strut including solenoid valve are considered. The proposed nonlinear controller is based on a hierarchical structure which contains three loops. The outer loop computes the expected optimal strut force on both touchdown and taxiing situation. The middle loop realizes the tracking of optimal strut force via backstepping design method and uses a RBF network to approximate the unmodelled nonlinear dynamics. The inner loop is responsible for precise tracking of valve current. A rigorous proof of stability is given and simulations are conducted on both touchdown and taxiing conditions to verify performance of proposed controller.