Research On Active Suspension Control Strategy Of SRM Electric Vehicle

Vehicle suspension system plays an important role in the process of vehicle driving,which has the characteristics of adjusting the height of the vehicle body and reducing the vibration of the vehicle body.Active suspension can improve the driving performance of the vehicle through control strategy,and then improve the ride comfort,operation stability and ride comfort.The following is the main research content of this paper.Firstly,this paper introduces some related knowledge of LMIs,and summarizes various robust H_∞ controllers and their solutions.The lemma commonly used in controller design is introduced,and a new linear matrix inequality(LMI)which can eliminate the uncertainty matrix is derived.Simulink is used to build the road roughness excitation model under different power spectral density.Then,in the actual driving process,the sprung mass of the suspension system will change with the load of the electric vehicle,and the spring stiffness and other parameters will also float within the design range with the temperature and other factors.Therefore,for the active suspension system with norm bounded uncertain parameters,a quarter electric vehicle active suspension model is established,and a new method to eliminate the perturbation matrix is applied.Considering the control error of the actuator,the state feedback vibration control strategy of the active suspension system is studied.This control strategy can ensure that the suspension system can obtain excellent attenuation of external disturbance within a certain range of parameter floating and actuator error,and also achieve the related time-domain hard constraints.Finally,a numerical example is given to verify the effectiveness of the method in time domain and frequency domain.Switched reluctance motor(SRM)has been widely used in hub motor-driven electric vehicles due to its high starting torque,wide speed range and high efficiency.However,due to the combined effect of unbalanced electromagnetic force and road interference,the comfort of traditional passive suspension is poor.It is difficult to reduce the unbalanced electromagnetic force simply by improving the manufacturing accuracy and assembly accuracy.Then,on the basis of the control strategy designed for the system with uncertain parameters,the model is extended to 1/2 active suspension model,the road interference and unbalanced electromagnetic force are regarded as external interference,and the actuator error and necessary time-domain constraints are fully considered.The control strategy for the electric vehicle active suspension is designed for the system with uncertain parameters.Finally,a numerical example is given The results show that the designed controller can effectively reduce the vertical acceleration and pitching acceleration of the car body,greatly improve the stability of the car,and ensure the relevant time-domain constraints.