Study On The Semi-active Suspension System Using Magneto-rheological Damper Of Heavy Articulated Dump Truck

Heavy Articulated Dump Truck (HADT) can well adapt to road, it has flexibilitymobile and strong power. HADT can well transport earth and stone when drive on thenon-road. As one of the important assembly of the vehicle, the performance ofsuspension has an important impact on ride comfort and control stability. Because ofthe stiffness and damping of traditional passive suspension can’t adjust, so it can notwell meet the ride comfort and control stability. The active suspension hasindependently force generator, so it can meet the ride comfort and control stability, butbecause of the higher cost, so it’s difficult to use on HADT. The semi-activesuspension based on Magneto-rheological fluid damper (MRD) does not require forcegenerator. Its damping can adjust in real-time, and can partly meet the ride comfort andcontrol stability, so it’s necessary to study.By study on the fluid properties of the magneto-rheological fluid and the workmode of MRD, then discusses several dynamics models of MRD. Based on the realparameters of HADT, the passive suspension of four freedom degrees and semi-activesuspension of front suspension were built. Using Laplace transformance, the transferfunction of sprung mass acceleration, suspension deflections, tire dynamic load to roadspeed were obtained. The vibration characteristics of front suspension were analysised.According to the ideal skyhook damping control strategy, optimal control theory, fuzzycontrol theory, the skyhook control system, optimal control system, fuzzy controlsystem of front susupension were built. By Matlab/Simulink, the passive suspensionand semi-active suspension using different control system were simulated under arandom road excitation．The vertical acceleration and angular acceleration of suspended mass, suspensiondynamic deflection and tire dynamic load of semi-active suspension were comparedwith passive suspension．The results show that the semi-active suspension based onMRD is an efficient measure to improve ride comfort．The semi-active suspension can increase the probability of suspension hit limit block and the probability of tirejumped off road, and can reduce the control stability and the safety of traveling. Agood theoretical reference for the practical application of semi-active suspension basedon MRD of front suspension of HADT can be provided by the results of the research.