ER suspension units for vibration control of a tracked vehicle

It is generally known that tracked vehicles are exposed to severe working environments such as rough road and complex ride behaviors. Therefore, high performance suspension units are required to isolate the vehicle body from terrain induced vibrations. This paper presents a novel type of suspension units utilizing an electro-rheological(ER) fluid. An in-arm type of ER suspension units(ERSU) is modeled and its spring and damping characteristics are analyzed with respect to the intensity of the electric field. Subsequently, a 16 degree-of-freedom model for a tracked vehicle is adopted and a neuro-fuzzy skyhook controller is designed for the semi-active ERSU. In the control algorithm, the vertical speed of the body and the rotational angular speed of the wheel are used as fuzzy variables. Vibration control performances of the tracked vehicle subjected to bump and random excitations are evaluated in both the time and frequency domains. In addition, the mobility of the vehicle with the limited power absorption is investigated with respect to the road roughness.