磁流变发动机悬置隔振性能与模糊PID控制

为了改善发动机悬置低频隔振特性,结合磁流变液体的流变特性,该文设计了一种磁流变发动机悬置,推导流动工作模式下液体液阻的表达式,运用键合图理论建立其键合图模型,推导磁流变悬置动刚度和阻尼角的表达式,应用Matlab软件编制程序对悬置低频动态特性进行仿真,仿真结果和试验结果基本吻合,证明了建模的准确性;建立了考虑悬架等效刚度和等效阻尼的发动机车架二自由度振动系统的数学模型,通过MATLAB/Simulink仿真模块搭建其仿真模型,并采用模糊PID控制方法对二自由度系统在不同工况下磁流变发动机悬置的隔振特性进行了仿真研究,结果表明磁流变悬置结合模糊PID控制方法能有效地降低车身加速度和传递到车架的力。该文为磁流变悬置的深入研究和发展提供了依据和参考。

Vibration isolation performance and fuzzy PID control method of magneto-rheological fluid engine mount

In order to improve the low frequency characteristic of engine mount, a MRF (Magneto-rheological Fluid) engine mount was designed in the paper based on the rheological property of MRF. The expression of liquid resistance in the flow mode was derived. Bond graph model of MRF engine mount was built to deduce the expression of the dynamic stiffness and loss angle. Then the dynamic characteristics at low frequency were simulated in MATLAB. The comparison of the simulation and experimental results proved that the model was accurate. Considering equivalent stiffness and damping, the two-degrees-of freedom model of engine-frame system was built and simulation model was built in MATLAB/Simulink. Then the isolation performance of the MRF engine mount was simulated by Fuzzy-PID control method under different working conditions. The simulation results proved that MRF engine mount combined with fuzzy PID control method was effective to reduce the body acceleration and the force transferred to the frame. This research provides a reference for further research and development of MRF mount.