Design And Experimental Research On An Electromagnetic Active Control Mount

With the development of automobile industry,consumers have put forward higher requirements for the NVH(Noise,Vibration and Harshness)issues of automobiles.In order to reduce the vibration and noise transmitted from the powertrain to the cabin,active control mounts(ACM)are used by more automobile manufacturers in high-class vehicles.To adapts to the market demand,an electromagnetic ACM is developed and a series of researches on vibration control of the electromagnetic ACM are conducted.The works contents can be summarized as follows.(1)According to the working principle of the electromagnetic ACM,the design parameters of the electromagnetic actuator are calculated,and a magnetic-moving electromagnetic actuator is designed.The output force-displacement characteristic curves of the magnetic-moving electromagnetic actuator are calculated by finite element methods and verified by experiments,the influence of the air gap between the mover and the stator on the output force-displacement characteristic of the electromagnetic actuator is analyzed.Under the premise of meeting the design requirements,the electromagnetic actuator with the largest output force is selected to study the relationship between the dynamic output force and the amplitude and frequency of the input current.(2)Based on the magnetic-moving electromagnetic actuator,an electromagnetic ACM sample is developed.The vibration accelerations of the MTS actuator are used as the input signals of the ECU(Electronic Control Unit)to control the electromagnetic actuator’s output force,and the minimum dynamic stiffness and loss angles of the ACM are measured.The results show that the dynamic stiffness and the loss angles of the ACM after control are significantly reduced compared with control before,and the dynamic stiffness can be reduced by 60.2% and the loss angles reduce by 16.1°.(3)In order to study the vibration control effects of the ACM on the powertrain and the car body,A single degree of freedom(DOF)and a two DOF vibration control test bench based on ACM are built respectively.The equivalent mechanical models of the single DOF system and the two DOF system are established.The lumped parameters in the equivalent mechanicalmodels are calculated by finite element methods.Under the control of PID controller,the sprung mass accelerations of the single DOF system and the unsprung mass accelerations of the two DOF system are calculated and tested separately.The results show that the PID controlled ACM can greatly attenuate the vibration and has good vibration control effects for both single DOF system and two DOF system.The research results provide technical supports for the development of ACM and has certain engineering application values.