Anti-roll Characteristic Analysis Of The Vehicle Fitted With Passive Hydraulically Interconnected Suspension System

Off-road vehicles lead to rollover easily because of having high center of mass, when driving at high speed in corner. Stiffer anti-roll bars limit the off-road performance of vehicles, so to ensure the off-road capability, some vehicles are installed with soft anti-roll bars which are lack of the roll-plane stiffness. The special off-road vehicle in this paper has been found the body roll angle is large when drive in the condition of the high speed steering in the actual operational. The vehicle’s roll stability need to be improved. A hydraulic interconnected suspension system is designed on the off-road vehicle to replace anti-roll bars to improve roll stiffness and have no effect on the off-road performance. The main research works of this dissertation are as follows:The correct vehicle dynamic parameters are the basic condition of the vehicle dynamic performance research. This paper adopts the method of parameter identification for vehicle, by using the time domain parameter identification method based on state variables to obtain modal parameters of the vehicle. Two physical parameter identification models are established, using the multi-objective optimization method to identify the vehicle physical parameters, and using ADAMS and vehicle test to verify the accuracy of parameter identification method. Then apply the proposed parameter identification method to obtain the basic kinetic parameters of the vehicle.The matching design of Hydraulically Interconnected Suspension System with the original off-road vehicle will greatly affect the vehicle’s roll stiffness, handling performance and ride performance. In this paper, the state space method has been used to establish the hydraulic and mechanical coupling dynamics model of the vehicle equipped with Hydraulically Interconnected Suspension System.This paper proposed the matching design process, based on the additional performance provided by the Hydraulically Interconnected Suspension System to determine the key physical parameters of the parametric analysis. Making the vehicle ride performance and the handling performance as the objective function of suspension design, by analyzing the obtained appropriate suspension parameter combination range-, applying the discrete design variable suspension multi-objective design method to obtain the optimal parameter combination. Then combining with engineering experiments to design key physical parameters of Hydraulically Interconnected Suspension in the actual structural design, after installation and commissioning the suspension.Through the analysis of the vehicle ride performance and the handling performance test to verify the feasibility of vehicle parameters identification and the accuracy of the matching method between the Hydraulically Interconnected Suspension System and the vehicle, at the same time validate the better performance of the Hydraulically Interconnected Suspension in improving off-road vehicles compared to the traditional suspension.In summary, this dissertation, whose research objective is an off-road vehicle fitted with passive hydraulically interconnected suspension system, has investigated into vehicle parameter identification method, the dynamics of this proposed suspension steady-state modeling and time domain modeling, the matching design process of this suspension and vehicle. As a result, this dissertation is with rather good academic merits and practical value.