Research On Control Of Automotive Semi-active Suspension System Based On Magnetorheological Damper

Theadvantages of automobile semi-active suspension are low cost,excellent performance and small volume.The realization mechanism of magnetorheological shock absorber is to control the damping force by means of the current flowing through the shock absorber coil.Its advantages are low energy consumption,fast response speed and become an important object in the field of automobile semi-active suspension.Based on the project of Liaoning Provincial Education Department," Research on the negative effect Control of Vertical Vibration of Hub Motor driven Electric vehicle "(No.JJL202015402),the magnetorheological shock absorber is used as the research object to create a model.At the same time,the semi-active suspension system is controlled based on the shock absorber.The main contents are as follows:Firstly,the performance of the shock absorber is tested,the properties of the shock absorber are analyzed based on the experimental data,and the Hyperbolic tangent model of the shock absorber is constructed on this basis.The simulation model is created on the simulation platform.The accuracy of the model is verified by comparing the simulation output with the actual experimental output.The inverse model of the magnetorheological shock absorber is designed to support the suspension control.Secondly,the model of random pavement and pulse pavement is constructed,and the model of 1/4 semi-active and passive suspension with two degrees of freedom is created.Based on this,the transmission characteristics of suspension system are analyzed,and the specific performance evaluation index is given,which provides support for the research of suspension control in the former.Then,taking the Sky-Hook damping control strategy as the starting point,the idea of Ground-Hook damping control is further introduced,and the limitation of single use of Sky-Hook damping control is improved,and the hybrid control method of Sky-Hook and Ground-Hook damping in semi-active suspension system is put forward.The influence of damping weight coefficient on the performance of suspension system is analyzed,and the parameter selection interval and the adjustable range of damping coefficient are defined.Finally,the fractional PID controller is combined to realize the closed-loop control of actuator by combining the hybrid control method of Sky-Hook and Ground-Hook damping with the fractional PID controller.Finally,based onthe model of positive andinverse ofmagnetorheological shock absorber and the pavement,the suspension control is studied by using the combined fractional PID control with the hybrid control method of Sky-Hook and Ground-Hook damping,and the performance of suspension system is evaluated at the same time.The results show that the model of MR shock absorber constructed in this paper can meet the requirements of simulation study of vehicle semi-active suspension system,and the proposed hybrid control method can suppress the vibration of vehicle non-spring load and spring load better.