Design And Semi-active Control Research Of An Automotive Power-train MR Mount

Automobile power-train is one of main vehicle vibration sources and it has great influence on vehicle comfortable performance. The ideal dynamic stiffness and damping of power-train mount should be frequency and amplitude dependent. The conventional passive power-train mounts do not meet all the isolation requirements in whole frequency range. In order to make the damping of power-train mount tunable in whole working frequency range, a semi-active Magento-rheological (MR) mount is proposed and a semi-active control method is adopted to control the damping of power-train mount.In this paper, a dynamic model is established to analyze the power-train mount system of a certain truck. Based on analyzing the passive mount damping's influence on isolation performance of power-train system, a MR mount which uses MR fluid as working fluid is proposed. Using the AG336 MR fluid of LORD Company, a new MR mount structure is designed, mainly including rubber spring design and damping part design. Then a bond graph model of designed MR mount is set up utilizing basic bond graph theory. Subsequently the mathematic model of MR mount is deducted and the state-space model is present. The dynamic characteristic of MR mount is simulated by MATLAB. The dynamic stiffness and damping is analyzed under different applied current and different mount structure dimensions.Finally, the vibration of MR power-train system is controlled under'on-off'damping control law and continuous damping control law respectively. Compared to isolation performance of passive power-train mount system, the semi-active controlled MR mount system has improved isolation performance greatly.