Study On Fluid-solid Coupling Modeling And Control Strategy Of Vehicle Semi-active Mount

Car as a means of transport has experienced hundreds of years of development,people on its performance requirements are getting higher and higher.Not only requires the quality of the car to be relatively light to achieve the purpose of saving energy,but also requires the comfort of the car ride to the passengers to bring a pleasant experience,which gave the vibration of the car put forward higher requirements.Car driving is mainly subject to two aspects of the excitation,the first is that uneven road surface caused by random road excitation,the second is the automobile engine to bring the imbalance inertia excitation.With the improvement of road conditions,road excitation has been greatly reduced and engine excitation has become a major problem of vibration isolation.The engine energizes the vibration through the mount to the body.Thereby increasing mount vibration isolation effect is the primary means to improve ride comfort.Active mount can achieve the desired vibration isolation effect,but the structure is complex,high cost,large energy consumption and low reliability,it is difficult to promote the application of large-scale.Semi-active mount is low cost and good reliability,has begun to get on the application of high-class cars and become one of the key technologies of automotive NVH.It is of great theoretical and engineering application value to study and develop the semi.active mount system of automobile engine,which greatly improves the NVH characteristics of domestic cars and improves the ride comfort of automobiles.In this paper,through the standard analysis,fluid-solid coupling modeling,sample development and other means to explore the semi-active hydraulic mount forward development of the design theory and methods.The main research contents are as follows:(1)This paper describes the research status of semi-active mount structure design,parameter identification and control strategy at home and abroad,and puts forward the main research contents of this paper;(2)The structure and working characteristics of the semi-active hydraulic mount are compared and analyzed,and the structural design scheme of the semi.active mount is developed.Based on the design goal of the mount of a car,the structural parameters of the semi-active mount are designed,and the semi-active mount sample development and performance test are completed.The semi-active mount lumped parameter model is established,and the extreme characteristics of the semi-active mount dynamic characteristic curve are deeply analyzed;(3)The semi-active mount 3D model is established.The finite element simulation of semi-active mount is carried out by using fluid-solid coupling theory.The parameters of semi-active mount lumped parameter model are extracted,and the dynamic characteristic curve of semi-active mount is obtained.The test results of the semi-active mount are tested,and the test results are compared with the simulation results,which verifies the correctness of the semi-active mount simulation model;(4)The dynamic model of the semi-active mount system based on the vehicle is established.The vibration characteristics of the vehicle under different working conditions such as idling,starting and impact are analyzed.The influence of the different modes on the vibration of the vehicle is compared.The corresponding semi.active mount control strategy is worked out;(5)The semi-active mount test program is designed,and the vibration data of the vehicle under different working conditions such as idle speed,start-up and impact are tested.The vibration of the vehicle under different modes of semi-active mount is compared and analyzed.The feasibility of semi-active mount control strategy is verified.The results show that the semi-active mount structure is designed to meet the vibration-proof demand of the automobile.The semi-active mount finite element flow-solid coupling simulation model can effectively predict the performance of the mount.Semi-active mount of the control strategy is correct and feasible to meet the different conditions of the car under the mount performance requirements.