Reconfiguration of stability and control strategy for some unmanned deformable vehicles

Abstract

An unmanned deformable vehicle can switch between wheeled driving and legged walking through reconfiguration. The system is prone to tipping instability when reconstructing from a vehicle state in wheeled motion to a humanoid state in legged motion. To improve reconfiguration stability, a center-of-mass position-adjusting mechanism was designed based on structure optimization design for the unmanned deformable vehicle. The zero moment point was adjusted by controlling a center-of-mass position-adjusting mechanism, thereby further improving the reconfiguration stability of the system. In this study, the structure of the unmanned deformable vehicle was designed and a reconfiguration kinematic model was established based on spinor theory. A reconfiguration dynamic model was established based on Newton-Euler equation, and the zero moment point was used as the stability criterion for the reconfiguration motion. To improve the reconfiguration stability of the system, simulated annealing algorithm was used to optimize the main parameters of the system under both basic and severe working condition reconfiguration processes. To further improve the reconfiguration stability, a variable universe-fuzzy control strategy was designed to control the stability of the reconfiguration process of the whole vehicle. The results showed that the reconfiguration stability could be significantly improved under various working conditions by using the stability control after the system was optimally designed.