Optimal Design Of Hydra-pneumatic Suspension Based On Ride Comfort

Ride comfort has relation to the vibration characteristics of vehicles, and thevibration characteristics of vehicles are dependent on the characteristics of suspension.Therefore, the characteristics of suspension determine ride comfort and comfort ofvehicles. As a type of new suspension system, hydro-pneumatic suspension is basedon oil as a delivery medium, with inert gas as the elastic medium. With goodnonlinear stiffness and damping characteristics, it can guarantee the vehicles runsmoothly during operation. This paper combined vibration theory with optimizationtheory in the design of suspension system to improve the ride comfort.Compared to light weight mining dump truck, heavy mining truck has manyadvantages, such as high working efficiency and low operating cost, so it is widelyused in large open-pit mine. Because of the road bumps, the vertical force acting onthe wheels has a strong impact, so the ride comfort is not well. Buthydro-pneumatic suspension has good nonlinear characteristics of stiffness anddamping, so it can greatly improve the vehicle ride comfort and the driver’scomfort. And hydro-pneumatic suspension can also reduce the extent of damage ofvehicle parts and improve the service life of the vehicle. It is for the goodcharacteristics of hydro-pneumatic suspension that most of mining dump truck usethis kind of suspension.The optimal design of a single chamber hydro-pneumatic suspension used in amining dump truck of360tons was discussed in this paper. A5-DOFs mathematicmodel for the heavy duty truck was derived in consideration of the nonlinearcharacteristics of hydro-pneumatic suspension and tire damping, which made themodel more realistic than traditional vehicle models. Under the loading input of therandom road surface and the pulses of road humps, an optimal design model wasestablished where the objective function was defined by the root meansquare(RMS)of the vertical acceleration at the gravity center of vehicle body. Thenumerical analysis was performed to examine the effect of the stiffness anddamping of the front and rear suspensions on the vibration response of vehicle bodyand human body. And the design parameters of the hydro-pneumatic suspensionwere optimized with a genetic algorithm. The results showed that the RMS ofvehicle body vertical acceleration decreases by25.6%, and the performance satisfied with the requirement of the ISO2631standard. Finally, this paperdiscussed the effect of fuzzy control and the stability of vibration response basedon optimal results a. And the effect of fuzzy control and the stability were verifiedby simulation.