Research On Integrated Control Of Vehicle Active Suspension And Active Steering System

With the popularity of automobiles and the improvement of people's living standards,higher requirements have been placed on the performance of various aspects of automobiles.Steering systems and suspension systems are two key systems in automotive chassis systems.Optimized suspension system can improve the ride comfort of the vehicle,and the optimization of the steering system can also improve the vehicle manipulation stability.Therefore,more attention has been paid to their integrated control research.Due to the interaction between chassis subsystems,the effect of improving single system on the comprehensive performance of chassis integrated system is not obvious,and there are many problems in the control of integrated system.Therefore,the difficulty of current research is to balance the optimization of the steering system and the suspension system in order to achieve the best overall performance of the integrated system.In this dissertation,the active suspension and active steering of automobile are taken as the research objects,and the predictive control and multi-objective optimization strategy of the vehicle chassis integrated system are studied,comprehensively considering the mutual influence of the two systems.Firstly,taking the whole vehicle as the research object,considering the system dynamics theory,taking into account the tire model and the road surface interference model,considering the interaction between the bottom plate systems,the integrated vehicle multi-degree of freedom model based on active suspension and active steering is established,and system state equation is derived,which lays the foundation for subsequent integrated control.Secondly,applying the model prediction theory to the integrated control system of active suspension and active steering,considering the actual running state of the vehicle and the relationship between the steering system and the suspension system,a predictive control algorithm based on the state space model is proposed,which includes model establishment,reference trajectory,rolling optimization and its constraints.The accuracy and effectiveness of the controller are verified by simulation.Finally,considering the influence of mechanical parameters and control parameters of integrated predictive control system,a multi-objective optimization system with steering stability and suspension safety as the objective function is established,and the optimization strategy of ant colony algorithm is adjusted to realize multi-objective optimization of the system.The simulation results show that the chassis integrated system designed in this paper improves the steering stability and suspension smoothness of the vehicle,and improves the comprehensive performance of the vehicle.The research content of this paper can provide theoretical support for the integrated control and multi-objective optimization research of automobile chassis system.