本研究主要是針對非對稱汽車頭燈進行參數化光學設計,探討如何應用參數化的變焦拋物面方程式於汽車頭燈之自由曲面式反射鏡設計,藉由調整方程式中的四項參數,達到歐規ECE R112及國內法規之光型要求,最後利用ZEMAX光學分析軟體與實體模型,進行比較驗證。 本研究以逆向工程的掃描作業將實體車燈反射鏡進行CAD建構,並依角度等分剖面,蒐集量測取得曲線點資料,利用點資料定義出變焦拋物曲線的a、b、c、d四項參數,而本研究共定義出八條變焦拋物曲線,並以此八條曲線建構出一參數化曲面反射鏡,再針對八組a、b、c、d四項參數進行靈敏度分析,得到各項參數對於光型變化的影響,進而調整出一組符合法規光型要求之參數設計自由曲面反射鏡。
The proposed research provided an alternative approach to design an automobile headlamp base on the parameterized optical design. Differing from the traditional free form reflectors, this paper uses eight variable-focus-parabolic curves, in which each curve is determined by four parameters, construct a free form reflector. In order to obtain a certain light pattern (e.g. Europe ECE R112 regulations for automotive headlamps), sensitivity analysis is necessary to determine the relationship between the curves’ parameters and the certain light pattern. Base on the results of sensitivity analysis, we can tune the useful parameters to finally satisfy the requested light pattern. The validity of the final design is demonstrated by means of ZEMAX simulations. It is shown that the parameterized free form reflector design yields a significant improvement in efficency compared to conventional free form reflector design.