Research On Semi-active Control Strategy Of Dual Spring MR Damper

Precision equipment is very vulnerable to environmental vibration during operation.With the different strength of vibration,the equipment will be damaged to different degrees,reduce the accuracy of the instrument,or cause structural damage.Therefore,in order to ensure that the precision equipment can work normally and orderly in the vibration environment,it is necessary to strengthen the vibration reduction measures for precision equipment,and constantly optimize the vibration reduction effect and reduce the vibration response as much as possible.The commonly used vibration control method of equipment is passive control,which has the advantages of easy realization and good stability,but it is difficult to adapt to the changeable vibration environment.Semi-active control can adjust the change of structural parameters according to the control strategy,and achieve better vibration reduction effect under the condition of amplitude and frequency changes.This paper presents a semi-active control strategy with dual spring MR damper for vibration isolation of precision equipment.The specific work of this paper includes the following aspects:This dissertation propose the dynamic model of dual spring MR damper,deduce the transfer function of the model,simulate the influence of different parameters in the structure on the vibration reduction.The mechanical properties of the dual spring MR damper are tested.The test results show that the damping coefficient and stiffness coefficient of the structure can be changed by the current of the inner tube damper and the outer tube damper respectively.In this dissertation,the phenomenon of bird head stabilization is applied to the field of vibration control.The vision system of bird head is simulated by high-speed camera and mark point detection algorithm.The vibration information is obtained by detecting the movement track of the mark point in the dynamic test,which is the input information of the vibration control system.Use the circular point and the cross point to identify and detect the mark point.The test result of the circular mark point is better,so the circular mark point is selected to apply in the semi-active control system of dual spring MR damper.In this dissertation,the forward model,the reverse model and the state space model of the dual spring MR damper are established to form the semi-active control system.The vibration displacement information obtained by the vision detection system is used as the input of the control system.The PID controller is designed to adjust the input current of the shock absorber,and enduce the shock absorber could export the damping force which adapted current vibration environment.Matlab / Simulink is used to simulate and analyze the control system,and build platform to test the vibration reduction effect,the test result is obviously better than the effect of passive control system,so the effectiveness of PID control strategy is verified.