中文摘要：

汽车助力转向系统可以在低速行驶时使转向轻便，在高速时保持一定的“路感”，以提高操纵稳定性。为了实现重型汽车的助力转向功能，本文介绍了一种新型电液助力转向系统的结构组成及工作原理，并结合具体实例介绍了系统助力特性的确定方法，得到了转向路感曲线，为控制器的设计提供了依据。

英文摘要：

Power Steering System is a system which reduces the steering force at low speed. Meanwhile, it also increases the steering farce at high speed to improve handling stability. In order to achieve power steering function in heavy - duty car. In this paper, the system composition and Working principle of the electro - hydraulic power steering system is introduced. We describe the basic and main layout forms. With concrete example, we research helping - hand characteristic, tile steering feel curve is obtained which provi- ding the design foundation of the controller.