汽车发动机磁流变悬置结构设计与振动控制

摘要

为实现宽频范围内对发动机振动进行积极隔振,提出了一种混合模式的磁流变悬置结构,利用有限元软件ANSYS分析了结构在不同电流下的磁场分布,从而得到悬置输入电流与悬置输出阻尼力的关系;同时,建立了磁流变悬置系统6自由度模型,设计了LQR控制器和模糊控制器对磁流变悬置系统进行隔振,仿真结果表明:LQR控制器和模糊控制器均能较好在宽频范围内的衰减发动机振动;模糊控制器相比LQR控制器具有更好的隔振效果.%In order to resolve noise and vibration problems generated by vehicle engine,a new mixed mode MR mount is proposed and an analytical model is established and is used to predict the performance of MR mount.The magnetic field distribution and relationship between input current and output force are got by using Ansys in different currents.Meantime,a six degrees of freedom dynamic model of an in-line four-cylinder engine which has three points mounting system is derived by considering the dynamic behaviors of MR mount and its state space form is established.LQR and fuzzylogic controllers are designed and synthesized to actively control the imposed vibration.The simulation results show that the proposed LQR or fuzzy-logic controllers can isolate the vibration of vehicle engine in a wide frequency range.The amplitudes can be suppressed well by employing this mount system.Its effectiveness is verified via experiment in the second part of this work.