New control logic based on mechanical energy conservation for aircraft landing gear system with magnetorheological dampers

Abstract

This research aims to develop a new control logic that ensures a high performance for an aircraft landing gear system with a magnetorheological (MR) damper at touchdown. Because the aircraft faces different conditions during landing, the mechanical energy that the landing gear must absorb to reduce the impact load is always different. The proposed control logic predicts the maximum strut stroke and calculates the optimal total force, based on the sink speed and the law of conservation of mechanical energy. It maintains the total force by controlling the MR effect until the end of the first compression stroke of the landing gear. To validate the high performances of the proposed control logic, drop simulations are performed at different sink speeds and sprung masses. In addition, the results obtained by the proposed control logic are compared with the conventional skyhook controller. The increment of 16% in the landing efficiency and the decrement of 42% in the jerk impact at the touchdown are significant performance improvement in the aircraft landing gear system.