Road-Holding-Oriented Control and Analysis of Semi-Active Suspension Systems

The most important function of a vehicle suspension system is keeping the tires on the road surface, imposing requirements on the road-holding performance. As is well known, a semi-active suspension can improve road-holding performance, but little effort has been made to build road-holding-oriented semi-active suspension controllers (RHSAC). This study improved four model reference controllers (MRCs) as RHSAC, including the road-Hook (RH), inverse ground-Hook (IGH), sky-Hook (SH), and ground-Hook (GH). These MRCs have optimal performances in different frequency ranges, and their working principle is analyzed from an energy perspective. To combine the advantages of different MRCs, a mixed control strategy is proposed to enhance the road-holding performance of the MRCs. By mixing SH and RH, the mixed SH-RH performs almost as well as a finely tuned model predictive controller, which outperforms any single MRCs. Based on CarSim-MATLAB cosimulations, the effectiveness of the mixed RHSAC controller is verified by various real road tests.