Chassis control in zero radius steer mode of four-wheel-independently actuated unmanned ground vehicle in remote control mode

This paper describes a heavy-class four-wheel-independently actuated unmanned ground vehicle, which is able to achieve zero radius steer (ZRS) based on the independent steered technique. The major novelties of the unmanned ground vehicle are introduced, especially the mechanisms to achieve independent steer. To enhance the performance of the vehicle to negotiate the complex terrains, a chassis controller for ZRS is proposed. The chassis controller includes a yaw moment controller and a tyre slip ratio controller. The yaw moment is determined by the ground command station, which is remotely controlled by the human operator. The tyre traction forces are distributed according to the tyre vertical load, and a sliding mode slip ratio controller is applied. Finally, the experiments based on the unmanned ground vehicle developed by the authors are conducted to verify the performance of the proposed controllers.