Research On Semi-active Vibration Isolation Platform Based On Magnetorheological Damper

Mechanical equipment due to the high intensity of the vibration of the power supply,equipment operation,external environment inevitably under the influence of vibration and shock,constant vibration and shock will influence the precision of mechanical equipment,reduce the service life of equipment and operating personnel's work efficiency,strong vibration will cause the resonance of devices,even cause equipment cannot be used.The traditional passive vibration isolation device with rubber and other materials can play a certain protective role,but generally speaking,the vibration isolation effect is poor,and the service life of the vibration isolation material is short.Based on the above problems,this paper establishes a kind of semi-active vibration isolation platform with parallel mechanism as the main body and MR damper as the semi-active actuator,and designs corresponding semi-active controller for it.First of all,this article choose high strength,stable performance of the parallel mechanism as the main body of vibration isolation platform,to improve the performance of vibration isolation of vibration isolation platform,using magnetorheological damper for vibration isolation platform damper,and the common mechanical model of MR damper was analyzed,in order to better repetition of mechanical properties of MR damper,exploring the acceleration of the MR damper are added to the model of hyperbolic tangent form improved hyperbolic tangent mechanics model,and through parameter identification,the accuracy of the model is demonstrated by the simulation analysis,etc.Second,determine to use have to interference in the same direction-3 RPS parallel mechanism as the main structure of vibration isolation platform,has carried on the degrees of freedom to 3 RPS parallel mechanism calculation and verification,and then analyzes its pose matrix,verify the independent position parameters and determine its has the characteristics of one translational and two rotational,and further on the kinematics analysis and prove the existence of the mathematical model of nonlinear characteristics.In order to solve the nonlinear,complex and low accuracy problems of the mathematical model of parallel mechanism,SolidWorks and physical modeling tool SimMechanics were used to establish the physical model of the isolation platform,and the feasibility of the model was verified through simulation analysis.Finally,in order to improve the isolation effect of the vibration isolation platform,an on-off controller based on the skyhook model was designed.In order to improve the flutter phenomenon existing in the on-off controller,the switch threshold was set to avoid the system flutter phenomenon caused by frequent switch switching.The semi-active sliding mode controller is designed,and the fuzzy sliding mode composite controller is combined with the fuzzy sliding mode controller to improve the chattering of the sliding mode controller,which lays a foundation for the semi-active control of vibration isolation platform.Subsequently,a simulation study is carried out on the semi-active vibration isolation platform based on the magnetorheological damper.The simulation results show that under the action of the semi-active controller,the vibration isolation platform designed in this paper has certain anti-interference performance and can effectively isolate the excitation from the lower platform.The research content of this paper has some guiding significance for the application of parallel mechanism in vibration isolation system and the physical modeling of nonlinear system.