A New Type of Electro-Hydraulic Power Steering System for Heavy-Duty Commercial Vehicles 2015-01-1502

The earth's fossil energy is not limitless, and we should be taking advantage of the highly developed fields of science and technology to utilize it more efficiently and to create a fully environmentally friendly life. Considering the prodigious amount of vehicles in the world today, even a small improvement in their energy-saving performance could have a significant impact.

In this paper, a new type of electro-hydraulic power steering (EHPS) system is described. It has two main advantages. First, it can significantly decrease the demand on the motor so that it can be used for a wider range of vehicles. Second, its pressure-flow characteristic can be programmed and is more flexible than hydraulic power steering (HPS) system. A prototype with a 500 W motor was applied to a truck with a front load of 2,700 kg, and static steer sweep tests were conducted to validate its feasibility. In addition, a mathematic model that included a vehicle model and tire model was built using Matlab/Simulink. A driving simulation was performed, and the results confirmed the feasibility of this EHPS system and excellent energy saving performance.