Semi-Active Suspension Design for Enhancing Vehicle Ride, Road-Friendliness and Braking Performance

This study proposes a novel semi-active hydro-pneumatic suspension design and investigates its performance potentials. The proposed new semi-active suspension design involves pneumatic interconnection between the front and rear suspension struts of the vehicle. The analytical formulations of suspension forces due to two suspension configurations, a passive unconnected and the proposed semi-active interconnected, are derived to analyze suspension properties. Based on a validated pitch-plane vehicle braking model, vehicle dynamic responses are conducted under a range of measured road roughness excitations and driving speeds, as well as braking inputs. The results of fundamental suspension properties and vehicle responses demonstrate the considerably potentials of the proposed novel semi-active suspension in improving vehicle pitch ride, pitch attitude control, and road-friendliness under random road excitations, without influencing vehicle vertical ride, and pitch attitude control when braking. These suggest the enhanced overall vehicle pitch-plane dynamics. Moreover, the proposed semi-active suspension design also offers considerably potential benefits in improving vehicle road-holding and therefore handling dynamics and directional stability.