2014-06-012024-05-13https://scholars.lib.ntu.edu.tw/handle/123456789/653868摘要：軌道車輛的頭燈用於遠距離警示作用，不同於一般車輛頭燈用於近距離障礙物照明，因此光場型分布設計大為不同。 另外為達到800公尺以上的照明需求，所需的燈泡瓦數可達200瓦特以上， 也高於目前車頭燈60瓦特， 對散熱設計造成挑戰。 因此在這計畫中, 我們提出利用建構自由曲面方法來設計用於軌道車輛頭燈的反光罩, 特別考慮其光照場型需要有聚光投射的功能。 其主要構想是反光罩本身來產生一預先設定好的光場分布。 其主要的設計參數考慮了反光面(S)， 光源 (O)以及目標平面 (O)。所有的光線經由光源 (O)， 藉著反射定律在反射面 (S)， 光的能量重新分配在目標面 (O)上。 因為反射面(S)的自由曲面設計， 我們可以改變目標平面 (O)上的光場分布。 接著，我們分析熱流情形， 並設計適當的多點發光二極體 (LED)擺設分布， 並挑選適當的金屬材質與結構。 我們採用LED陣列串連的原因是降低所需的驅動電流， 來減少不必要熱能的產生。 根據我們初步設計結果， 我們的熱阻 (thermal resistance)應當小於1.3K/W， 相當於熱傳導係數5000 W/(m2‧K)， 才可達到所需的散熱要求。 我們會根據模擬與設計結果製作數個樣品供廠商來測試。 最後， 我們會整合反光罩， 光學結構與散熱鰭片來組成一完整的頭燈系統。驅動電路將由合作廠商鉅濰設計分別提供。 本產學合作案的優勢是LED陣列可以配合自由曲面設計排列， 達到最佳出光效率。 而由合作廠商提供的驅動電路，可以保護LED在過熱環境自動斷電。 如此， 可以用最小的驅動功率， 減少熱源產生， 達到增加LED軌道車輛頭燈的使用壽命。 <br> Abstract: The headlights on railed vehicles are used for warning, unlike those on automobiles which are mainly designed for lighting obstacles. Therefore, the far-filed lighting patters are dramatically different from each other. In addition, headlights on railed vehicles require much higher input power (~200 watt) than those on automobiles (~60 watt) to meet the requirement of 800-meter lighting intensity. In this project, we propose a constructive procedure aimed at developing an optical system for designing the reflector of a headlight for a given light intensity distribution on the target (road), considering the special requirement of railed vehicles, especially for light focusing and projecting. A design concept is described in which the reflector alone produces the specified illumination pattern. Consider a reflector system consisting of a reflecting surface S, a point light source O, and some object T (road). Assume that the source O, reflector S, and object T are positioned so that the rays reflected off S are incident on T. Depending on the geometry of S the energy radiated by O and redirected by S is distributed on T to produce a certain illumination pattern. Next, we analyze the requirements in thermal aspects in theory. With the results of theoretical analysis, we design the light emitting diode arrays (LEDA) with optimized structural parameters and choose appropriate packaging materials. We opted for LEDs connected in series in order to minimize heating problem by reducing driving current. According to this design, several samples will be made and tested. The thermal resistance of packaging is estimated be less than 1.3K/W when equivalent heat transfer coefficient of cooling system is about 5000 W/(m2‧K). Finally, we integrate a novel freeform multi-reflector, an effective heat sink to form a complete headlamp module for high-beam functions for railed vehicles. Driving circuits are provided by Advanced Electric Design Co. The main advantage of our design is that light emitting diode arrays can be placed in accordance with the free from reflecting surface to optimize the external lighting efficiency. The driving circuit board of LEDs has self-regulated function to prevent over heating issues. As of result, we can use the minimum electric power to achieve maximum lighting efficiency with less heat and longer life time.LED燈LED lighting