車輛方向操縱系統高速擺振研究

High speed shimmy of vehicle steering system

簡求奮(Qiu-Fen Jiaon)

指導教授 ： 洪振發

共同指導教授 ： 孔慶華

國立臺灣大學/工學院/工程科學及海洋工程學研究所/碩士(2006年)

https://doi.org/10.6342/NTU.2006.03139

摘要

汽車行駛在特定狀況下，車輪會發生繞主銷軸線的持續迴旋擺動，而致車體之橫向擺動，並可傳至轉向系統形成方向盤繞軸心迴轉振動，此種振動現象稱為擺振(shimmy)與一般車體振動現象不同。
本文探討與汽車擺振問題相關的車體和轉向連結系統設計參數，建立全車多體運動分析模型。在底盤動力計上進行實車試驗，藉由量測結果確認車體發生擺振的車速，據以更新分析模型；再進一步以更新後之模型進行靈敏度分析，與轉向連結系統設計參數調整最佳化，以達到降低擺振的目的。
本文建立一套分析程序，對於車體有擺振現象發生時，針對整個方向控制傳遞路徑中影響擺振的參數進行設計靈敏度分析，據以提出降低其敏感度之對策，以降低擺振的抖動量或將其發生的車速範圍移出常用車速區段，以提高行車品質。

關鍵字

擺振 ； 多體動力學 ； 全車模型 ； 靈敏度分析 ； 最佳化 ； 實車試驗

並列摘要

When an automobile driven under some conditions, the tires may swing about the kingpin axis continuously, cause the yawing of car body, and the vibration may be transferred to the steering system to induce the rotating vibrating of steering wheel. This phenomenon is termed as shimmy, which has some difference from usual car body vibrations.
This paper reviewed the parameters related to the shimmy problem of cars. The multi-body dynamic model for a whole car was established, to predict the car speed when significant shimmy will occur. The shimmy experiments of a real car on chassis dynamometer were performed to determine the car shimmy speed; the experimental results were also used as reference basis for parameter updating of analysis model, in order to reduce the model uncertainties. The design sensitivity analysis and design optimization for the modified model were carried out to find out the sensible design parameters, which will provide important information to select a reasonable way form improvement of shimmy levels.

並列關鍵字

shimmy ； multi-body dynamics ； sensitivity ； optimization ； real car experiment

參考文獻

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