Design, dynamic analysis, and experiments of MRF dampers for lunar landers

Abstract

With the further exploration of the Moon, lunar landers need to land in complex and unexplored areas. However, current lunar landers are confined to basic landing conditions (low landing velocity and plain terrains). This research proposes a novel lunar lander with magnetorheological fluid (MRF) dampers that can adapt its damping forces to various complex landing conditions. The design process and coupled electromagnetic hydrodynamic model analysis of the lunar lander were systematically elucidated. According to the derived theory model of the damping force, a fuzzy control law is proposed. The controllable damping forces under different control currents are simulated according to the proposed fuzzy control law. Additionally, landing dynamic simulations of landers with different dampers are carried in MSC. Adams to compare with their landing performances. MRF dampers under fuzzy control can decrease the largest acceleration of the lander cabin by 63.6%. Finally, prototype drop simulations and experiments are performed, which results match each other well. By increasing the control current from 1 A to 2 A, the damping forces of the MRF damper increase approximately 20% in both the simulations and experiments. Simulations and experiments prove that MRF dampers can be used for energy impact absorption as variable dampers.