Development of an asymmetric magnetorheological suspension towards improved ride comfort

Under rough road conditions, the suspension system requires asymmetric damping characteristics on the damper. However, conventional magnetorheological dampers (CMRD), constrained by their symmetric flow-channel structure and high static friction, not only struggle to meet the differentiated performance demands in the compression and rebound stroke, but also induce pronounced stick–slip behaviour, thereby degrading riding comfort. To address these issues, this paper proposes a novel asymmetric magnetorheological damper (NAMRD). By incorporating an adaptive pressure-relief channel in parallel with a check valve, the proposed structure fully decouples the compression and rebound flow paths, thereby enabling controllable asymmetric damping characteristics while significantly reducing system static friction. To accurately describe the dynamic behaviour of the check valve, an HB-CM model is developed, based on which a prototype NAMRD is manufactured and subjected to mechanical testing on an MTS test platform to validate the model’s accuracy. The static friction of the damper is also tested. Experimental results show that, compared with a traditional CMRD, the critical gas pressure of the NAMRD is reduced from 3 MPa to 1.5 MPa, and the static friction force is reduced by 45.87%. Furthermore, to achieve operating-condition-adaptive damping, an extended Kalman filter −based (EKF) road excitation estimation method is introduced, and the system-level validation of the control strategy, together with the NAMRD device, is carried out on a quarter-car vibration test platform. The results demonstrate that the proposed system achieves significantly improved vibration isolation performance and riding comfort under rough road conditions.