Improvement of Heavy Vehicles Ride and Braking Performance via Combined Suspension and Braking Systems Control 2011-01-0437

Due to the importance of the fast transportation under every circumstance, the transportation process may require a high speed heavy vehicle from time to time, which may turn the transportation process more unsafe. Due to that fact the truck safety during braking and the ride comfort during long distance travelling with high speeds should be improved. Therefore, the aim of this work is to develop a control system which combines the suspension and braking systems. The control system consists of three controllers; the first one for the active suspension system of the truck body and cab, the second one for the ABS and, the third for the integrated control system between the active suspension system and the ABS. The control strategy is also separated into two strategies. The first strategy is called the ride comfort control strategy for the improvement of the truck ride comfort during long distance travelling, and the second strategy is called the braking control strategy for the improvement of the truck braking performance via ABS and the integrated control system. The Fuzzy-Logic control theory is used to construct the controlled systems. The simulation model includes 3-axle long chassis truck suspension model with cab suspension, truck braking system model, road surface model, and tyre road interface model. The influence of the road roughness, tyre-road friction coefficient and truck speed on the performance of the control strategies is also studied. The simulation results demonstrated that using Fuzzy-Logic control with the controlled suspension systems and with the ABS provides a significant improvement in truck ride comfort and braking performance under different driving conditions. Furthermore, the integrated control system between the active suspension system and ABS improves the truck braking performance at different operating conditions in comparison with the same truck without integrated control system.