Research On Vibration Control Of Steering Wheel Of Commercial Vehicle At Idle Speed Based On An Domain Index Decomposition Method

The steering system is the core system that determines the driving direction and the lifeline of automobile driving,and the steering wheel is a key component of the steering system in direct contact with the driver,and its vibration water is usually used as a key index to evaluate vehicle comfort and safety.Excessive steering wheel vibration will not only lead to driver health problems,but also cause traffic safety accidents.With the development of the times,customers' pursuit of car comfort and safety is becoming more and more intense,and the problem of steering wheel idle vibration becomes more acute,which is often the key reason for customers to refuse to pick up the car,and it has also become one of the main problems troubling designers.In order to solve the problem of abnormal steering wheel jitter under idle condition,taking the steering wheel as the trust region point,a trust region index decomposition method based on the correlation vibration path analysis of trust region points is proposed in this paper.The synthesis includes the influence effect of each decomposition subsystem except the steering system on the trust region point,and takes the optimization of the trust region point vibration level in the idle speed range as the research goal to realize the optimal control of the steering wheel vibration level in the global angle of the whole vehicle,so as to improve the simplicity and efficiency of steering wheel vibration diagnosis and control analysis.The main contents of this paper include:(1)Theoretical research.Based on the implementation process and analysis mechanism of the trust domain index decomposition method,the optimization mathematical models of the whole vehicle layer and the key subsystem layer are established,and the steering wheel idle vibration control index and design criteria are proposed and determined from the optimization direction of frequency avoidance and vibration isolation and vibration absorption.(2)Research on hybrid modeling method based on trust domain index decomposition method.The dynamic theory of rigid-flexible multibody model is studied,the confidence region point of the implementation method is established,the vibration transfer path associated with the trust domain point is analyzed,and the key subsystems on the path are selected to analyze the structural characteristics.Combined with a variety of software(Hypermesh finite element software,Adams/car multi-body model simulation software and Adams/Flex flexible body processing software,etc.)to establish the flexible body model of each key system,detect the modal information of the subsystem structure,combine with other subsystems to form the vehicle rigid-flexible coupling model,and complete the parameter calibration of the rigid-flexible subsystem model.(3)The idle speed experiment is carried out and the virtual characteristic excitation source system is established.With reference to the implementation steps and driving conditions of the idle speed test,the vibration signals on the powertrain mount are collected in reverse and driven in the reverse direction on the simulation model,and the resonance characteristics of the trust region points are found within the acceptable error range.Using the signal excitation point of the resonance characteristic excited by the excitation source,the equivalent resonance characteristic excitation source model is established,and the idle frequency sweep experiment at traversing speed is carried out to verify the consistency of the measured and simulated response characteristics at the trust domain point.By comparing the changes of the response intensity at the trust point before and after the disconnection of the associated transfer path branches of multiple trust domain points,the main vibration transfer branch paths affecting the vibration intensity of the trust domain points are identified.(4)Optimization analysis of decomposition layer system based on trust domain index decomposition design criteria.According to the transmission direction of "excitation source-transfer path-trust region point" and with reference to the established decomposition criterion of trust region index,the adaptive improvement and optimization analysis of each key decomposition layer system is carried out in the direction of avoiding frequency,isolating vibration and reducing vibration.At the same time,the effect of the improvement of the key subsystems of each layer on the trust domain point is observed,and finally the optimal design of the trust domain point response on the whole vehicle layer is realized by effect screening.