High Accuracy And Parameter Consistency Aimed Mechanical Characteristic Modeling And Time Delay Compensation Control Experiment In Loop Of Magnetorheological Damper

Compared with the active suspension,which needs external power source,high energy consumption and high cost,and the passive suspension,whose stiffness and damping parameters can no longer change once it is selected for loading,semi-active suspension is expected to achieve comprehensive performance similar to that of active suspension with little energy consumption.Magnetorheological damper,as a key component of MR semi-active suspension,the modeling quality of its mechanical characteristic and time-delay compensation control strategy are of great importance to the control precision and control effect of semi-active suspension.Therefore,the mechanical characteristic model of magnetorheological damper with high accuracy and good parameter consistency is constructed in this paper.Based on this model,taylor series-H₂composited time delay compensation control strategy is designed,and the control strategy is verified by testing in the loop.The main research contents can be summarized as follows:Firstly,a mechanical characteristic model based on the Asymptotically saturated magic formula of magnetorheological damper was proposed.On the basis of retaining the high parameter consistency,the model effectively tracks the variation of hysteresis width of velocity characteristic curves under different excitation frequencies by adding the hyperbolic tangent term of piston acceleration.At the same time,the hyperbolic tangent function with saturation property is used to replace the original sine function to eliminate the drooping phenomenon of the velocity characteristic curves when the piston velocity is large,which improves the modeling accuracy of magnetorheological damper.Secondly,based on the testing and modeling of the mechanical characteristic of magnetorheological damper,a Taylor series H₂ composited time-delay compensation control strategy was proposed for two degrees of freedom quarter vehicle MR semi-active suspension model.The H₂ method is used three times in this composited control strategy.For the first time,the H₂ method is used to expand the control force with time delay into a first-order Taylor series,and based on this,the comprehensive performance index of H₂suspension with time delay compensation is constructed.In order to solve the problem of unsatisfactory control effect caused by hard constraint of predictive control force,the H₂index item of predictive control force was added to the above comprehensive performance index of suspension,so as to realize soft constraint predictive control force and improve the tracking accuracy of its ideal control force.In the third time,the H₂ method is used to replace the first-order delay compensation equation to obtain the ideal control force in the process of calculating the predictive control force,so as to further improve the control precision of the predictive control force.Thirdly,on the D-class road surface with a driving speed of 50km/h,using the MATLAB/Simulink to build simulation model of passive suspension,the ideal semi-active suspension and the MR semi-active suspension controlled by Taylor series-H₂composited time-delay compensation control strategy with the response time delay of the MR damper were 10.45ms and 28ms respectively.Finally,in order to verify the working effect closer to the actual working condition than the single computer simulation,on the basis of designing the Kalman filter and discretization of the system,two YXSPACE SP2000 rapid prototype controllers were used to carry out the HIL test of MR semi-active suspension controlled by Taylor series-H₂composited time-delay compensation strategy.The results show that the new asymptotically saturated magic formula model has the advantages of good precision and high parameter uniformity.Compared with the passive suspension,the comprehensive performance indexes of MR semi-active suspension controlled by Taylor series-H₂ composited time-delay compensation control strategy are reduced by 27.21%and 26.72%respectively,only 0.28%and 1.20%worse than the ideal semi-active suspension when the time dealy are 10.45ms and 28ms.The results of HIL test show that the comprehensive performance index of MR semi-active suspension controlled by Taylor series-H₂ composited time-delay compensation control strategy is3.70%larger than that of the ideal semi-active suspension.