Hierarchical control strategy design for a 6WD unmanned skid-steering vehicle

Skid-steering vehicle has strong maneuverability. There are a variety of skid-steering wheeled vehicle designed for military or civilian at home and abroad. In this paper, based on the need of skid-steering vehicle dynamic control, a hierarchical controller is designed for a 6×6 skid-steering vehicle. The vehicle speed and steering is controlled through driving torque of motor to following the desired vehicle speed and yaw rate. Contrary to the common approaches by designing a two-tier control strategy, the reference wheel speed generator is used to calculate the wheel speed and the wheel speed follower is used to reach the target wheel speed. To perform small radius cornering maneuvers, a dynamic control strategy for steering when vehicle speed is zero is also designed. The Trucksim/Simulink co-simulation model is developed and simulated in the model. Compared with the data of hierarchical control strategy and traditional control strategy through simulation, it is proved that the hierarchical control strategy can make the vehicle follow the target value quickly and accurately. And setting the simulation in different peak value of friction coefficient, it is proved that the hierarchical control strategy has strong robustness.