第六章、 結論與未來展望
6.2 未來工作
未來工作分成以下幾點陳述：
一、在最佳化輪胎與路面間摩擦力分配部分，是將上層計算所需的力量適當地分配 至每個輪胎，故控制的車輛要為四輪可以獨立驅動和轉向，但是若考慮現在市面上最為 普遍的車輛為後輪驅動和前輪轉向，此時若經由最佳化分配出後輪所需的側向力也無法 控制後輪轉向角產生所需之力，所以我們所設計最佳化輪胎與路面間摩擦力分配的成本 函數將不再適用，為了克服這點成本函數要如何選擇，或者加入一些限制，這都是未來 可以再繼續分析與研究的地方。
二、摩擦力係數估測部分目前只有用於輪胎縱向力控制器內平衡點的範圍限制，因 為估測方法是基於縱向滑動，在縱向滑動率較小的情況下摩擦力係數並無法準確的估測，
所以並沒有將估測的結果用於最佳化輪胎與路面間摩擦力分配，未來可以在摩擦力係數 的估測上再作更準確的估測，最佳化輪胎與路面間摩擦力分配若可以利用摩擦力係數估 測結果的資訊，將可以做更有效率的分配。
三、在本研究中忽略了車身的側傾(Roll)與俯仰(Pitch)運動的影響，對於質心位置較 高的休旅車，高速下或者大角度的轉向容易造成側翻，上層控制器可以考慮加入車身的 側傾與俯仰對橫擺運動動態影響，或在順滑平面設計上加入側傾或俯仰運動的平衡點，
設計控制上層輸入跟隨給定的參考值。
四、未來實驗驗證部分，初期會以建構單一個輪胎動態實驗平台(Quarter car model) 與模擬軟體模擬的車輛動態整合成一個 Hardware-in-the-loop 的實驗環境，驗證下層控制 器控制的結果；之後進展到實車驗證，上層控制器會需要回授車輛的縱向、側向速度和 橫擺角速度，以及需要估測車輛質心側滑角，就如第四章所提到的：車輛縱向與側向速 度可以利用全球定位系統(GPS)來判斷質心的位置與移動速度；用陀螺儀來量測橫擺角 速度；質心側滑角可借助一些估測方法估測，所以這些都是控制器在實車驗證上會需要 考慮如何獲得的資訊。
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參考文獻
[1] Y. Hori, “Future Vehicle Driven by Electricity and Control—Research on Four-Wheel- Motored „UOT Electric March II‟,” IEEE Transactions on Industrial Electronics, vol. 51, no.
5, pp. 954-962, Oct. 2004.
[2] P. He, and Y. Hori, “Experimental Evaluation of Dynamic Force Distribution Method for EV Motion Control,” in IEEE Power Conversion Conf. PCC’04, Nagoya, Japan, Apr. 2007, pp. 682-687.
[3] P. He, and Y. Hori, “Improvement of EV Maneuverability and Safety Force Distribution with Disturbance Observer,” WEVA Journal, vol. 1, pp. 258-263, May 2007.
[4] Y. Furukawa, N. Yuhara, S. Sano, H. Takeda and Y. Matsushita, “A Review of Four-Wheel Steering Studies from the Viewpoint of Vehicle Dynamics and Control,” Vehicle System
Dynamics, 18, pp. 151-186, 1989.
[5] J. Ackermann, “Robust Decoupling, Ideal Steering Dynamics and Yaw Stabilization of 4WS Cars,” Automatica, vol. 30, no. 11, pp.1761-1768, 1994.
[6] V.Nikzad. S. and M. Naraghi, “Model Reference Tracking Control of A 4WS Vehicle Using Single and Dual Steering Strategies,” SAE 2002 Transactions, Journal of Passenger
Cars : Mechanical Systems, no. 2002-01-1590, pp.1841-1851.
[7] T. Pilutti, G. Ulsoy and D. Hrovat, “Vehicle steering intervention through differential braking,” Journal of Dynamics Systems Measurement and Control Transactions of the ASME, vol. 120, Issue:3, pp. 314-321, Sep. 1998.
[8]Y. Shibahata, K. Shimada and T. Tomari, “Improvement of Vehicle Maneuverability by Direct Yaw Moment Control,” Vehicle System Dynamics, vol. 22, pp. 456-481, 1993.
[9] M. abe, “Vehicle dynamics and control for improving handling and active safety: from four-wheel steering to direct yaw moment control,” Proc. Insn. Mech. Engrs.,vol. 213, Part K,
71
pp. 87-101, June 1999.
[10] P. Raksincharoensak, M. Nagai and M. Shino, “Lane keeping control strategy with direct yaw moment control input by considering dynamics of electric vehicle,” Vehicle System
Dynamics, vol. 44, pp. 192-201, 2006.
[11] E. Esmailzadeh, A. Goodarzi, G.R. Vossoughi, “Optimal yaw moment control law for improved vehicle handling,” Mechatronics, vol. 13, pp. 659-675, 2003.
[12] M. Mirzaei, “A new strategy for minimum usage of external yaw moment in vehicle dynamic control system,” Transportation Research Part C, vol. 18, pp. 213-224, 2010.
[13] E. Bakker, L. Nyborg and H.B. Pacejka, “Tyre Modeling for Use in Vehicle Dynamics Studies,” SAE 870421., 1987.
[14] J. J. E. Slotine and W. Li, Applied Nonlinear Control, Englewood Cliffs, NJ: Prentice Hall, 1991.
[15] S. Boyd and L.Vandenberghe, Convex Optimization, New York: Cambridge University Press, 2004.
[16] J. R. Ellis, Vehicle dynamics, London, United Kingdom: London Business Book Limited, 1969.
[17] O. Mokhiamar and M. Abe, “Effects of model response on model following type of combined lateral force and yaw moment control performance for active vehicle handling safety,” JSAE, vol. 23, pp. 473-480, Oct. 2002.
[18] U. Kiencke and L. Nielsen, Automotive Control Systems, 2nd ed. Germany:
Springer-Verlag Berlin Heidelberg, 2005, ch. 10.
[19] J. J. E. Slotine and S. S. Sastry, “Tracking control of nonlinear systems using sliding surfaces with application to robot manipulators,” Int. J. Control, vol. 38, pp. 465-492, 1983 [20] C. Geng, L. Mostefai and Y. Hori, “A Hybird-like Observer of Body Slip Angle for Electric Vehicle Stability Control: Fuzzy Logic and Kalman Filter Approach,” IEEE Vehicle Power and Propulsion Conference(VPPC), Harbin, China, Sep. 2008, pp. 1-6.
72
[21] O. Mokhiamar and M. Abe, “How the four wheels should share force in an optimum cooperative chassis control,” Control Engineering Practice, vol. 14, pp. 295-304, Mar. 2006.
[22] R. Rajamani, Vehicle Dynamics and Control, New York: Springer-Verlag, 2006.
[23] J. Ahmadi, A. Khaki-Sedigh and M. Kabganian, “Adaptive Vehicle Lateral-Plane Motion Control Using Optimal Tire Friction Forces With Saturation Limits Considerations,” IEEE