Research On Design And Control Of Continuously Damped Hydraulically Interconnected Suspension System

With the continuous development of science and technology and the improvement of social living standards,people’s demand for vehicle comfort and handling stability is also increasing.Traditional passive suspensions are increasingly difficult to meet people’s needs because they cannot take into account the vehicle’s ride comfort and handling stability.Active suspension is limited by the problems of high energy consumption,high cost and reliability.Therefore,the hydraulic interconnection suspension has become a new research hotspot,because it can decouple the vibration mode of the vehicle and achieve independent control of the suspension motion,thereby greatly improving the handling stability of the vehicle.In this paper,the hydraulic interconnection suspension is taken as the research object,and the improvement of the vehicle’s handling stability and comfort as the research goal.A continuous damping adjustable scheme is designed.And modeling and simulation verified that the semi-active hydraulic interconnection suspension can further optimize its dynamic performance.First,the working principle of the fixed damping valve in the passive hydraulic interconnection suspension and the working mechanism of the continuous control shock absorber damping adjustment are analyzed.The electro-hydraulic proportional throttle valve is used as the adjustable damping valve of the hydraulic interconnection suspension.And build an electro-hydraulic proportional throttle valve model in Amesim,the simulation shows that the flow rate and the input current have a strong linear relationship.The basic components of the hydraulic interconnection suspension are mathematically modeled,and the accuracy of the modeling is verified by a fixed damping valve bench test.Secondly,three schemes of adjustable damping valve are analyzed.Compared with continuously adjustable damper,the results show that the scheme of parallel structure of electro-hydraulic proportional throttle valve and common damping valve has better linearity of damping force with current change.The steady-state analysis of the hydraulic interconnection suspension of the semi-vehicle shows that: the opening of the hydraulic cylinder port damping valve has a great influence on the vertical damping of the system,and the effect of the opening of the accumulator port damping valve can be ignored;The valve opening and the opening of the accumulator port damping valve are all related,and the opening of the accumulator port damping valve has a greater effect on roll damping.Thirdly,the advantages and disadvantages of the control algorithms such as sky-hook control,ground-hook control,acceleration-driven-damper control,and mixed sky-hook and ADD control analyzed.Based on the sensitivity of the adjustable damping valve at different positions,it is proposed to only control the hydraulic cylinder port adjustable damping valve at low speed,and use the fuzzy mixed skyhook and ADD control algorithm;control the accumulator port and the hydraulic cylinder port damping at high speed and turning around uses the ground-hook control algorithm.Finally,simulation analysis of ride comfort and handling stability.Ride comfort simulation shows that under the excitation of B-level road surface,mixed sky-hook and ADD control greatly improves the vehicle ride comfort compared with the passive hydraulic interconnection suspension;under the multi-level mixed road excitation,fuzzy mixed skyhook and ADD control is further improved ride comfort.The handing stability simulation shows that: the ground-hook control reduces the peak value of the roll angle under the fish hook test,and reduces the height of the car body on the high-speed and straight road surface.The research shows that the continuous damping adjustable hydraulic interconnection suspension provides a new method to solve the contradiction between vehicle stability and smoothness.