本研究首先以小型車常用之雙A臂式懸吊系統為基礎下,建立四分之ㄧ車懸吊數學模型,利用向量迴路分析輪胎上下跳動時懸吊系統與輪胎轉角的變化情形;並且利用Adams/Car中的懸吊模型驗證其向量迴路方程式的正確性。其次,在懸吊桿件與車身連結處加入滑塊,並藉由四分之ㄧ車向量迴路方程式找出滑塊移動時,輪胎轉角最敏感的滑軸角度,作為設定滑塊滑動方向的依據,然後依前述所建議的滑軸角度建構Adams/Car可變幾何懸吊模型系統。 本文也經由懸吊模擬方式取得可變幾何懸吊模組的側傾特性,其中包含側傾中心高度變化與輪胎前束等參數變化趨勢,作為模糊控制器中的專家經驗取得方式,並依照此懸吊特性設計一組可隨車輛行駛狀況,調整懸吊幾何接點之可變幾何懸吊模糊控制器,且結合Adams/Car與Matlab/Simulink兩套軟體進行整車動態控制與分析;同時也導入主動式懸吊系統,評估兩者控制方式的差異性與耗能分析。最後,模擬結果得知可變幾何懸吊系統可有效減少車身之側傾現象,並且具有較低耗能之優勢。
In this paper, the enhancement of vehicle handling characteristics using variable geometry suspension is investigated. The variable roll center suspension concept in a double wishbone suspension is proposed. In order to achieve the controllable of roll center, a slider block is installed between upper control arm of suspension and vehicle body. Then, this paper also analyzes how suspension linkage geometry affects the toe angle by using closure equation. Thus, the most sensitive of toe angle is found. Therefore, in order to evaluate the handling performance, a full car model with variable geometry suspension is constructed using multi-body dynamic analysis software Adams. In addition, we use the fuzzy control to implement human’s heuristic knowledge and define the control input as the motion of the slider. Finally, we also combine the software “Adams/Car” and “Matlab/Simulink” with the fuzzy controller for the full-vehicle model analysis. The control input for fuzzy control of front suspension is the motion of the slider. Moreover, this paper also compares the power consumption between variable geometry suspension system and active suspension systems for roll control strategies. The result shows that the roll angle of vehicle attitude can be improved by using novel variable geometry suspension and active suspension control. Also the simulation demonstrates that the variable geometry principle will deliver cost effective performance in the future.