Research On Dynamic Characteristics And Control Strategy Of Engine Magnetorheological Mount

The vibration generated during engine operation has a great impact on the ride comfort of the car,and the powertrain mounting system can attenuate the vibration generated during engine operation to a certain extent.Compared with passive mounts,the dynamic characteristics of magnetorheological semi-active mounts are continuously adjustable and can improve the vibration isolation performance of the mounts in a wide frequency range,so they have good prospects for engineering applications.In this paper,we focus on two aspects of magnetorheological mount dynamic characteristics and control strategy,and the main work is as follows.In view of the dynamic characteristics of magnetorheological fluid,the rheological properties of magnetorheological fluid materials are firstly introduced,the structural design of magnetorheological suspension based on the flow mode is analyzed and the working principle of this mount is clarified on this basis;considering the influence of magnetic circuit on the dynamic characteristics,the structure and size of the magnetic circuit inside the suspension are designed and determined,and the finite element simulation analysis is adopted to verify whether the designed magnetic circuit can meet the effective Secondly,the model of the magnetorheological suspension is established and simulated based on the total parameter method,and the static and dynamic characteristics of the machined magnetorheological mount are tested and compared with the simulation results.On the one hand,it is verified that the static stiffness meets the design requirements;on the other hand,by loading different currents,the dynamic stiffness of the sample is investigated with the change of current,and it is verified that the suspension sample can achieve continuous vibration isolation in a wide frequency range.Therefore,from the perspective of magnetorheological powertrain mounting system,the vibration isolation requirements of the powertrain mount system are analyzed,and the vibration response of the single-degree-of-freedom system is analyzed based on the vibration isolation theory,and the dynamics model of the system is established on this basis.Meanwhile,combined with the established dynamics model,the relevant calculation software is prepared to calculate and analyze the magnetorheological mount system to meet the vibration isolation requirements,taking the reasonable configuration of the inherent frequency of each order of the system and the magnitude of the energy decoupling rate as indicators.Finally,in order to verify whether the designed control strategy can achieve the ideal vibration isolation performance under the control conditions,a ten-degree-of-freedom model of the whole vehicle is built considering the engine excitation and road excitation,and a forward and inverse mathematical model describing the control current and controllable damping force is established by combining the theoretical equation of controllable damping force and the average magnetic induction strength under different currents derived from the simulation analysis;the Fuzzy-PID switching The Fuzzy-PID switching strategy is used to build a simulation model in MATLAB/Simulink environment for simulation analysis.The simulation results show that the designed Fuzzy-PID controller can reduce the vibration transmitted from the engine to the body under the control condition and improve the vibration isolation performance of the powertrain mounting system under the idling condition and the economic speed driving condition compared with the uncontrolled powertrain mounting system.