Control Performance of Damping and Air Spring of Heavy Truck Air Suspension System with Optimal Fuzzy Control

The air suspension system of heavy trucks not only improves the vehicle’s ride comfort but also reduces the negative impact on the road surface. In order to evaluate the performance of the control damping (CD) and the control air spring (CAS) of the vehicle air suspension system on the ride comfort and the road friendliness, a three-dimensional (3D) nonlinear dynamic model with 14 degrees of freedom (DOF) of the heavy trucks and optimal fuzzy control (OFC) with control rules optimized by the genetic algorithm (GA) are proposed in this study. The root mean square (RMS) acceleration response of the tractor and the dynamic load coefficient (DLC) at the wheel axles are chosen as objective functions under the various operating conditions. Contrastive analysis of the RMS and DLC values with the passive (P), CD, and CAS methods of the air suspension system is carried out respectively. The research result shows that both the CD and CAS methods remarkably improve the ride comfort and road friendliness of the heavy trucks in comparison with P, especially the CAS method has an obvious effect on mitigating the road damage in comparison with the CD method; conversely the CD method is better than the CAS method to improve the tractor’s ride comfort under different operating conditions.