Modeling Of Magnetorheological Damper And Vibration Control Of Semi-active Suspension

As the semi-active device that has outstanding performance Magnetorheological(MR)damper has the advantage of high output within a short time,the continuous adjustable damping force,good durability,simple structure,so that it obviously improves the performance of vibration isolation system.But the description for the strong non-linearity of MR damper is difficult,domestic and overseas scholars presented a variety of models.These models have the common feature that these models cannot reach the high precision of fitting and simple expression,and the identification algorithm for these models is still room for improvement.Combining the analysis in theory,study on experiment and numerical simulation,an algorithm that can meet the requirements of the accuracy and simple expression was proposed,a new MR damper exponential model was proposed,and the vibration control of suspension system was studied based on the new model.The process of parameter identification was briefly described,and the validity of the pattern search algorithm was verified.The HT-9711 material fatigue testing machine was used to begin the loading test on the MR damper and the experiment data was obtained.The process and features of non-linear least squares,genetic algorithm,and pattern search algorithm were introduced and compared in detail.Then the fitting characterize of several normal MR damper parameter models were compared.Based on above content,the performance of pattern search algorithm on the aspect of model identification were checked.The result of comparing three algorithms and fitting the experimental data based on a variety of operating conditions prove its effectiveness in parameter identification fully.The features of main models was summarized,and the MR damper exponential model was proposed.The pattern search algorithm was used to estimate parameter,then the fitting accuracy of the exponential model with three normal parameter models was compared.The result proves the simple structure(only three unknown parameters)and high accuracy of exponential model.Then many groups of experimental data were used to test the fitting accuracy of the exponential model.The result also proves the high accuracy of exponential model in various current levels,frequency,and amplitude.The process of checking Bingham improved model that article proposed is similiar to exponential model,it also has the high level accuracy.The vibration control of semi active suspension system was studied based on MR damper exponential model.The 1/4 dynamics model of vehicle suspension was built,and the expression form of the active strategy and semi-active strategy were introduced detailedly.Then the performance of the suspension system at different road excitation and control strategies were analyzed carefully.The research result give full expression to the advantage of the semi-active strategy.At the same time,the result embody that the exponential model is rational and practical.