Performance Analysis And Control Of A Variable-stiffness Damping Semi-active Suspension

Automobiles have become an important and important way of life in modern urban life.With the good yearning for people's quality of life,the improvement of vehicle comfort has become an indispensable part of improving people's quality of life.Since the semi-active suspension has better control performance than the passive suspension,and the relative active suspension cost is relatively low,or will become the development trend of the future vehicle suspension,this paper chooses the semi-active suspension as the research object.In this paper,a new type of variable stiffness variable damping semi-active suspension structure is designed and its structural diagram and model diagram are obtained.The equivalent stiffness and equivalent damping expression are obtained by dynamic analysis,and the existing variable stiffness is obtained.The equivalent expression of the variable damping semi-active suspension structure is compared and analyzed.In order to analyze the performance of the new variable stiffness variable damping semi-active suspension structure,the 1/4 body dynamics model of passive suspension,existing variable stiffness variable damping semi-active suspension and new variable stiffness variable damping semi-active suspension are established respectively.Modeling and its dynamic equations.In the simulink,the time domain model of the deceleration zone is simulated when the vehicle passes through a sinusoidal section speed reducer at a speed of 10 m/s.The 1/4 body vibration model of the passive suspension,the existing variable stiffness variable damping semi-active suspension,the new variable stiffness variable damping semi-active suspension are established respectively,and three vibration models are obtained by using the second law of Newtonian motion.The vibration differential equation.Firstly,the technical core of fuzzy control is analyzed.The realization steps of fuzzy mathematics and fuzzy control are introduced.The membership function and fuzzy rules are determined according to the needs.Then the composition and principle of PID controller are briefly introduced.Finally,the two are respectively A semi-active suspension is designed with a fuzzy PID controller adapted to it in the MATLAB/simulink module.Vibration simulation of a quarter-vehicle model equipped with a passive suspension,equipped with a conventional variable stiffness variable damping semi-active suspension,and a new variable stiffness variable damping semi-active suspension,through the vertical acceleration curve of the vehicle body and the dynamic deflection curve of the suspension Compared with the tire dynamic load curve and its rms value,the comfort and steering stability of the three suspensions are analyzed.It shows that the new variable stiffness variable damping semi-active suspension can be significantly improved under the condition of small sacrificing vehicle handling stability.The ride comfort of the vehicle.The driving speed and road conditions of the three suspension 1/4 vehicle models were sequentially changed,and the influences of road conditions and vehicle speed on vehicle comfort and steering stability were compared and analyzed.The vibration of the vehicle with three kinds of suspension vehicles passing through a sinusoidal section speed reducer is simulated respectively.The vibration of the vehicle is measured by the vertical acceleration curve of the vehicle.The results show that the new variable stiffness is damped and semi-active.The suspension has better filter performance than the passive suspension and the existing variable stiffness variable damping semi-active suspension through the speed bump,which can improve vehicle vibration.