Design, analysis, and validation of a distributed drive vehicle with the reconfigurable wheeled-tracked system

A reconfigurable wheel-tracked system (RWT) can transform between a wheel and a track and combine the benefits of both locomotion mechanisms. By deforming between different modes, it enables a vehicle to traverse paved roads at high velocity and exhibit great adaptability to various terrains in an off-road environment. It gradually becomes a key technology to improve a vehicle’s holistic performance when working under extreme conditions. This paper proposed a novel reconfigurable wheel-tracked system that can change the area of contact path to transform between a wheel and a track. The mechanical structure of the system is first introduced. To further explore the potential of the reconfigurable system, a four-motor distributed drive vehicle outfitted with RWTs is designed. A planar 3-DOF dynamic model of the distributed RWT vehicle is then established to investigate how mode transition affects the vehicle’s angular velocity and turning radii. The shear stress-shear displacement relationship is used for terrain-track interaction modeling. A prototype is then built for field tests. In static transformation tests, the prototype can transform from wheeled mode to full-tracked mode in around 12s. Dynamic experiments show that the mode of RWT dramatically influences the dynamics of the distributed drive vehicle. When the vehicle is turning steadily, in inward-tracked mode, it has the minimum turning radius and the maximum speed, while the vehicle in track mode has the opposite characteristic. The tendency of the turning radius is contrary to that of the angular velocity. Finally, the proposed vehicle was validated through field experiments, and the relative error between the theoretical model and the tests is about 19.1%, indicating that the numerical model is reasonable. In summary, the vehicle designed in this study gives an insight into what future augmented ground platforms might look like.