Research On Consistency Control And System Parameter Optimization Of Electro-hydraulic Hybrid Steering System

The electro-hydraulic hybrid steering system can dynamically switch the working mode according to the current working conditions of the vehicle,which can effectively improve the handling performance of commercial vehicles and reduce the energy consumption of the steering system.It is the development direction of the steering system of large commercial vehicles in the future.For the electro-hydraulic hybrid steering system,how to further improve the vehicle performance by optimizing the parameters,and how to eliminate the inconsistency of steering sensation caused by the different dynamic characteristics of each actuator are two key issues in the design and development of the electro-hydraulic hybrid steering system.Therefore,this paper mainly focuses on these two key issues,the specific contents are as follows:Firstly,a closed-loop system dynamics model composed of electro-hydraulic hybrid steering system,driver model and vehicle dynamics model is established.The electro-hydraulic compound steering system consists of three parts: electric power module,hydraulic power module and steering moment mechanical transmission module,which lays a foundation for system parameter optimization and controller design in the following chapters.Secondly,in order to further reduce steering energy consumption,improve steering stability and steering road feeling,the quantitative formulas are established,and the multi-objective optimization design system of composite steering system is presented.Combining the parallel computation of PSO algorithm with the scalar search of MOEA/D algorithm,a multi-objective optimization algorithm of MOPSO/AD is proposed,and the parameters of electro-hydraulic steering system are optimized by the proposed algorithm.Finally,in order to eliminate the inconsistency of steering sensation caused by the electro-hydraulic hybrid steering system in various mode switching,the steering mode switching strategy and the dynamic compensation strategy of steering sensation during the switching process are proposed,taking into account the driver's ideal steering sensation and the energy consumption of the actuator.On the basis of this,considering the requirement of anti-jamming performance of the system controller,an electro-hydraulic steering system controller based on robust theory is designed.The research results of this paper can provide theoretical basis and technical support for the design and development of electro-hydraulic compound steering system.