隨著科技的進步，汽車引擎的振動與噪音愈來愈小，而且車室內部的隔音效果也愈來愈好，因此當車輛靜止而引擎以怠速運轉時，車內幾乎感覺不到引擎的振動與噪音，駕駛人經常會誤以為引擎已熄火，而再度啟動引擎，造成環齒輪與小齒輪撞擊，可能降低啟動系統使用壽命，及增加啟動時的噪音。本研究之目的在於進行引擎防重覆啟動裝置之研製。首先，進行引擎轉速量測實驗、依據引擎啟動與怠速的特性，歸納出引擎啟動狀態的判定法則。接著，以組合語言撰寫轉速量測與啟動馬達控制程式，然後，設計及製作介面電路。最後，實際接到引擎上加以測試，以驗證所設計裝置之可行性與正確性。由結果顯示，所發展啟動裝置，可成功地防止引擎重覆啟動，並維持引擎正常啟動及運轉。除此之外，所發展系統具有低成本、體積小、再啟動時間短、及容易加裝等優點，可有效應用於各型車輛上。

The vibration and noise of a car engine are much less than they were due to the advance of the technologies. A driver almost cannot feel them when the vehicle is at rest and the engine is running at idle speed. A double starting occurs occasionally, and it causes an impact between the ring gear and the pinion. Therefore, the service life of the starting system may be reduced, and the noise during starting may be increased. The purpose of this paper is to develop an engine control device for preventing double starting. First, the principle for determining the engine starting status is summarized by carrying out experiments measuring crankshaft speeds at starting and idle. Then, a program for measuring the speed of the crankshaft and controlling the starter is developed by employing Assembly language. Furthermore, interface circuits for controlling the starter are designed and implemented. Finally, the feasibility of the proposed system is verified through an online experiment by employing it in a car engine. The experimental results indicate that the developed system can successfully avoid unwanted duplicate ignition, both start and keep the engine running properly. In addition, the advantages of the proposed system are cost effectiveness, compact size, short re-starting time, and easy upgrades; therefore it can be effectively applied to all sorts of vehicles.