Research On Coupling And Cooperative Control Of Active Suspension And Steering System Of Multi-Axle Emergency Rescue Vehicle

Multi axle emergency rescue vehicles often need to operate in complex and dangerous working conditions,so compared to passenger cars,higher requirements are put forward for the safety,handling stability,and driving smoothness of multi axle emergency rescue vehicles to meet the needs of land rescue.Considering the impact of multi-axle steering system and active suspension system on driving smoothness and handling stability,as well as the complex coupling relationship between the two systems,studying the collaborative control of multi-axle emergency vehicle active suspension and steering system has important practical application value.First of all,in order to deeply study the all wheel steering behavior of multi axle vehicles,a dynamic model is established to analyze the transient response and steady-state response of all wheel steering,and a new dual Robust control strategy is proposed to rapidly converge the steering system’s sideslip angle and yaw rate to the ideal reference track,and simulation research is carried out under two typical working conditions.Secondly,by using magic formulas to analyze the nonlinear relationship between tire vertical load,lateral force,and tire sideslip angle,an active suspension sliding mode variable structure controller is designed.Simulation analysis under random road conditions shows that compared to traditional passive suspension and canopy controllers,The active suspension sliding mode variable structure controller proposed in this article based on the active suspension ride comfort model can significantly improve the ride comfort of threeaxle emergency rescue vehicles.Thirdly,the coupling principle and cooperative control strategy of the multi axle emergency rescue vehicle active suspension system and the all wheel steering system are studied.Under different dynamic models,the active suspension anti roll controller,the active suspension sliding mode variable structure controller and the multi axle all wheel steering dual robust controller are designed respectively.Next,a collaborative control strategy is proposed and simulated under different operating conditions to compare the driving smoothness and handling stability of vehicles under collaborative control and individual control,in order to verify the effectiveness of the coupling system collaborative control strategy proposed in this paper.Finally,a steady-state rotation test of the test vehicle was conducted,and the entire vehicle was tested and studied at different speeds on different test sites.The test results show that compared with the single control,the collaborative controller designed in this paper can reduce the root mean square value of the pitch angle and roll angle of the emergency rescue vehicle by about 25%,the root mean square value of the roll angle acceleration by about 30%,the root mean square value of the pitch angular acceleration by about 24%,and the root mean square value of the vertical acceleration of the vehicle body by about 23%,The vehicle ride comfort(active suspension sliding mode variable structure controller designed based on ride comfort model)and handling stability(active suspension anti roll controller designed based on handling stability model and multi axle all wheel steering dual robust controller)have been optimized to extent.