八輪車輛之非阿克曼穩態轉向特性分析

Analysis on the non-Ackermann Steady Cornering Behaviors of Eight-Wheeled Vehicles

楊明憲(Ming-Shien Yang)

指導教授 ： 劉霆

國立臺灣大學/工學院/機械工程學研究所/碩士(2015年)

https://doi.org/10.6342/NTU.2015.01986

摘要

本研究主要探討多軸轉向的八輪車使用不同轉向幾何配置時的穩態轉向特性及其轉向時之評估。首先藉由運動學以及牛頓力學，建立八輪車輛轉向模型的幾何關係式與力平衡方程式。此模型的方程式中，包含八個輪胎的獨立轉向角、側滑角、正向負載轉移以及使用重型車輛的輪胎Magic Formula。建立八輪車輛轉向模型後，由於本研究發展之數學模型難以求得解析解，採用Newton-Raphson的數值解析方式，以三自由度力平衡方程式做為目標函數搜尋數值解。針對阿克曼與平行轉向以及其他各種不同的轉向幾何，進行數值分析，以前雙軸阿克曼幾何的轉向特性為基準，進一步分析比較各種轉向幾何配置的效果，歸納出多軸轉向配置對於八輪車輛的穩態影響。利用本研究發展的模型，可對八輪車輛的多軸轉向配置、側滑現象、正向負載轉移、轉向力分配對車輛行為的影響能有更完整的了解。

關鍵字

穩態轉向 ； 側滑角 ； 正向負載轉移 ； 八輪車輛 ； Newton-Raphson 法 ； 多軸轉向 ； 重型車輛Magic Formula

並列摘要

The purpose of this study is to understand the effect of different multi-axle steering configurations to the steady turning behaviors of eight-wheeled vehicle with multi-axle steering. First, an eight-wheeled independent steering vehicle model has been developed, and its motion equations based on the geometry and force equilibrium of the vehicle are derived for the steady state analysis. This model has included eight independent steering angles, slip angles, load transfer, and the Magic Formula tire model of heavy duty vehicles. Applying Newton-Raphson method on the model, numerical solutions can be found. The solutions can be used to establishing benchmarks for cornering characteristics of Ackermann steering, then the effects of non-Ackermann steering have been studied. By using this model, the slip angle, cornering force and load transfer of each tire can be thoroughly realized. Finally, according to the tire characteristic above, the steady cornering behaviors of eight wheel vehicle can be described.

並列關鍵字

Steady cornering ； slip angle ； load transfer ； eight-wheeled vehicles ； numerical analysis ； multi-axle steering ； Magic Formula of heavy duty vehicle

參考文獻

[6] Lukowski, S. A., Fiedler, R. A., Claar, P.W., “Investigation of a road-vehicle directional behavior under steady-state conditions”, SAE Special Publications, Issue 884, pp.49-56, 1991.

[7] Lee, A. Y., “Performance of four-wheel-steering vehicles in lane change maneuvers”, SAE paper No.950316, 1996.

[9] Irie, N. and Kuroki, J., “4WS technology and the prospects improvement of vehicle dynamics”, SAE paper No.901167, 1990.

[10] Yoshimi, F., Naohiro Y., Shoichi, S., Hideo, T., Yoshinobu, M., “A review of four-wheel steering studies from the viewpoint of vehicle dynamics and control”, Vehicle System Dynamics, Vol. 18, No. 1-3, pp.151-186, 1989.

[12] Itoh, H., Oida, A., “Dynamic analysis of turning performance of 4WD-4WS tractor on paved road”, Journal of Terramechanics, Vol. 27, No. 2, pp. 125-143, 1990.