Research on Energy Saving of Hybrid Power Steering System for Heavy Commercial Vehicles

With emphasis on Carbon Neutrality and Emission Peak today, energy saving and emission reduction is an important development direction in the automotive field. Fuel-powered heavy commercial vehicles (HCV) cannot equip with EHPS system and EPS system, which have great advantages of energy consumption, due to the large steering load. Due to this, the vast majority of HCV have to spend more than 3% of their total energy consumption on their steering systems at present. Aiming at the energy-saving problem of HCV steering system, this paper proposes a new type of hybrid power steering system consisting of an accumulator electric-hydraulic power steering (A-EHPS) subsystem and a C-EPS subsystem. Firstly, the principle of the system is introduced. Secondly, the energy-saving potential of the system and the difficulties in the control strategy design are pointed out, and an effective control strategy with high efficiency is proposed. The proposed system can reduce the power reserve of the HCV power steering system to 1kW and can apply to the 24V low-voltage supply system, meeting the needs of fuel-powered HCV. Finally, the HIL test of the energy-saving strategy is carried out for a large bus with a total mass of 18 tons. The results show that compared with the constant flow EHPS system, the proposed system with the high-efficiency controller achieves an energysaving effect of more than 80%.