A Control Strategy for Height Adjustment in Closed-Loop Air Spring Suspension System

This study examines a closed air spring suspension system. To address issues such as over-inflation, over-deflation, and excessive overshoot during vehicle height adjustment, a threshold control method is implemented. This method controls the triggering conditions for height adjustment and effectively reduces overshoot while enhancing precision. Experimental results indicate that this control strategy decreases overshoot and improves accuracy. However, risks are associated with varying threshold settings across different control modules, which can lead to over-control. A fuzzy PID controller is developed to resolve this issue. This controller adjusts PID parameters in real time based on fuzzy rules, thereby refining height adjustments. During testing, it was found that the degree of electromagnetic valve opening could not be controlled by the fuzzy PID controller. Therefore, a control strategy to adjust the compressor speed is designed. Experiments show that the fuzzy PID controller, capable of regulating compressor speed, effectively addresses the problems associated with threshold control. Additionally, this approach increases the rate of height adjustment. Real vehicle tests confirm the feasibility of the proposed control strategy. The results demonstrate that the closed air spring suspension system achieves smoother and more efficient height adjustments with improved accuracy.