Passive Skyhook Suspension Reduction for Improvement of Ride Comfort in an Off-Road Vehicle

With the use of Routh stability criterion and Pade approximation technique to simplify the passive skyhook damping suspension system, a full-car model involving the reduced-order ISD suspension was established for the analysis of ride comfort. The genetic algorithm of unified objective function was applied for the optimization of structural parameters. Comparative analysis of the system performance was conducted among the conventional passive suspension, the passive skyhook damping suspension and the reduced-order ISD suspension. The results show that the root-mean-square value of body acceleration, tire dynamic load and suspension working space of the reduced-order ISD suspension are close to those of the passive skyhook damping suspension and the main performance can be achieved. It illustrates that the overall performance of the reduced-order ISD suspension can be close to the passive skyhook damping suspension and the research theoretically verified the effectiveness of the reduced-order ISD suspension. Furthermore, a integrated inerter device with inerter and damper connected in series is developed, which is then arranged in the front and rear suspension of an off-road vehicle for road test. As a result of this paper, it was demonstrated that, the reduced-order ISD suspension can suppress the vertical, pitch and roll vibration of vehicle body.