前輪獨立式轉向系統之設計與分析

Design and Analysis of Front Independent Steering System

林新凱(Shin-Kai Lin)

指導教授 ： 尤正吉

國立臺北科技大學/機電學院/車輛工程系所/碩士(2008年)

摘要

現今小型車輛之輪胎轉向角因受機械式轉向系統機構上的限制，左右兩輪轉角需維持一定比例。無法在低速轉向時有較小的轉彎半徑，且不能使車輛以較高的速度過彎，所以本研究將運用線控轉向之優點，利用向量迴路方程式分別建構四分之一與二分之一車懸吊及轉向模型並分析其運動情形，且加入荷重轉移來調整輪胎轉角之車輛過彎特性，分別依造不同車速進行內外側輪轉向角調整，讓車輛有更佳的操控特性。
本研究運用前輪獨立式轉向系統之數學模型來修正車輛過彎時的輪胎轉向角之設計，並考量輪胎轉彎力正比於輪胎荷重之特性，將所需之輪胎轉向角依前軸兩輪之轉彎力或荷重比例進行分配，使車輛能夠有較優於傳統轉向系統之轉向特性，提升車輛在轉向時的穩定性與操控性。最後由ADAMS/Car軟體建構出前輪獨立轉向系統全車模組，並運用軟體Matlab進行數學模型之全車運動模擬分析來驗證研究中提出之轉向策略。

關鍵字

獨立式轉向系統 ； 向量迴路方程式 ； 荷重轉移

並列摘要

The traditional steering system cannot be operated simultaneously well in low and high vehicle speed because of the one degree-of-freedom mechanism connected left and right tire. For low-speed cornering, the turning radius become longer, in addition, it can not turn stably at higher velocity. According to these reasons, we want to use steer-by-wire system for research to improve these defects. This research builds the mathematical models of quarter-car and half-car for vehicle during cornering, and analyzes suspension link geometry relative to roll center by using closure equation. A vehicle with independent steering system can adjust the tire angle automatically in accordance with load transfer and running conditions.
This study using the mathematical models to design tires steering angle when vehicle during cornering, therefore, considering the load transfer for front axis two tires when vehicle during cornering and the direct proportion between cornering force and tire load, brings up a new steering concept about using load transfer to modulate front axis two tires steering angle to make vehicle conform to different speed, then the vehicle steering characteristic can be better than traditional steering system. This research also uses mathematical models and Matlab software to describe vehicle dynamic and calculate how to modify two tires steering angle. Finally, we build an independent steering system and introduce the proposed steering concept to analysis results through ADAMS/Car software.

並列關鍵字

independent steer ； closure equation ； load transfer

參考文獻

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