Counterbalancing Speed Control for Hydrostatic Drive Heavy Vehicle Under Long Down-Slope

This paper deals with the counterbalancing speed control issue of the closed hydrostatic drive hydraulic system of the heavy transportation vehicle under long down-slope. First, a novel method to realize the balancing to the down-slope weight force and the regulation to the motor speed is proposed. Next, a global fast terminal sliding mode control method is introduced to the speed control system. Then, addressing the load torque disturbance, a disturbance observer is designed for rejecting to disturbance. Finally, a test rig is established for verifying the effectiveness of the control method. The simulation and experimental results show that the designed continued hydraulic counterbalancing speed control system can smoothly regulate the traveling speed and restrain the load disturbance.