Research On Application Of Magnetorheological Damper To Vehicle Suspension System Performance

In recent years,the development of the automobile industry has been particularly rapid,which has also led to the continuous improvement of people's requirements for the comfort and safety of vehicles.However,the traditional passive suspension system has been unable to meet people's requirements due to its poor response effect and slow response speed.Magnetorheological damper has many advantages,such as low energy consumption,only a few amperes of current can obtain a large damping force,it is controlled by electromagnetic field,fast response speed,convenient control,and it can be integrated with the vehicle electronic control system,there is no need for a complicated mechanical structure.Therefore,a semi-active suspension system with adjustable damping can be designed using magnetorheological damper to improve the ride comfort and safety of the vehicle.In this paper,LQG control strategy and single neural network PID control strategy are used to control the vehicle body suspension and seat suspension respectively.The specific research work is as follows:(1)Design of magnetorheological damperThe contradiction between the effective length of damping,the damping gap and the adjustable damping force in the design of magnetorheological damper was analyzed,and a sliding valve type shock absorber composed of piston head,piston sleeve and baffle was designed.The structural parameter design and structural material design of this shock absorber are carried out.After that,the magnetic resistance of the designed shock absorber under the extension stroke and compression stroke was analyzed,and it was proved that the damper meets the performance requirements in terms of strength and damping,and can be used for the development of suspension systems.(2)Establishment of vehicle model and road modelThe vehicle model uses a quarter vehicle model,and the vehicle suspension system equations are obtained through the mechanical equilibrium equation to represent the current driving state of the vehicle.The seat suspension equates the person and the seat into three three-degree-of-freedom models with mass and rigidity.The road model adopts a random excitation model obtained from Gaussian white noise through filtering and transformation.(3)Research on control strategy of semi-active suspension systemThe LQG control algorithm has stable performance and good robustness.The compound genetic algorithm tunes its weight matrix,which reduces the error of manual weight selection and the development time to maximize the advantages of the algorithm.For the seat suspension,since the excitation it receives is weakened by the body suspension system,a simpler single neural network PID control algorithm is adopted to realize semi-active control.The semi-active suspension system studied in this paper can apply the studied control algorithm under the action of random road excitation and deceleration road excitation,and achieve better vibration damping performance than passive suspension.In the time domain response of the semi-active suspension system designed in this paper,compared with the passive suspension,the center of mass acceleration is optimized by 41.84%,the suspension dynamic deflection is optimized by 32.65%,the tire dynamic deflection is optimized by 38.52%,and the driver vibration acceleration Optimized 19.01%.