The hydraulic part of the EHSSS with single axle is simplified in Figure 5. Obviously, electro-hydrauliccontrol system contains a servo solenoid valve and two steering actuation cylinders, and these two cylindersare controlled by one valve. System parameters are shown in Figure 5. In order to get the main characteristics, a proper simplification is made, so we assume that (1) hydraulic oil source is ideal, that is to say, ps = 0,while return pressure is 0; and (2) the pipes between valve and cylinders can be neglected owing to the smalllength