Heavy-load variable stiffness lunar wheel based on adjustable tensegrity unit

Abstract

Manned lunar landings have been prioritized as interstellar exploration capabilities continue to improve. Among them, the heavy-duty manned lunar rover is an essential tool for human lunar exploration. However, the lunar surface presents a highly complex and dynamic environment, rendering traditional lunar wheels inadequate for simultaneously addressing multifaceted requirements such as landing, locomotion, and vibration isolation. A heavy-load variable stiffness lunar wheel based on adjustable tensegrity unit is proposed, offering three stiffness states with a range of up to 178.25%. First, the wheel’s variable stiffness mechanism and corresponding applicable scenarios are introduced, along with the theoretical solution for vertical stiffness. Next, the static simulation using the finite element method (FEM) is performed to validate the theoretical solution. The lateral stiffness, impact tolerance, and single-point deformation capacity of the wheel are investigated. Results indicate that the current wheel addresses the limitations of traditional flexible lunar wheels with low lateral stiffness. Meanwhile, the wheel’s impact tolerance and single-point deformation capacity effectively meet the needs of rovers landing and operating on rugged terrains. Finally, a reduced-size prototype of the wheel is fabricated based on 3D printing technology, and the effectiveness of the variable stiffness mechanism is experimentally demonstrated.