以單晶片對雙霍爾感測器之電動車窗作防夾控制

Abstract

隨著汽車工程的電子技術發展迅速，汽車上附屬的電子設備增加，相對的這些電子設備的安全性和可靠性的問題，也就備受矚目與關注；本論文之目的在探討電動車窗防夾系統的安全性與可靠性。使用C語言程式將程式寫入電動車窗的MCU上的單晶片(Microchip PIC16F1827)實現防夾。並由電動車窗馬達軸的旋轉，帶動N極與S極繞經兩顆霍爾感測器，產生的pulse訊號，作為電動車窗上升下降位置的判定，並計算pulse間隔的時間來設定防夾的門檻值，以有限狀態機判斷車窗自動或手動控制，並藉由狀態轉移控制車窗上升、下降或是防夾。用參數式設定當電動車窗在上升的過程中且進入防夾區時，若pulse訊號週期超過門檻值三次，或霍爾感測器訊號超時，才啟動防夾機制，避免誤判而意外啟動防夾機制。

As electronic technology in automotive industry is developing rapidly, the automotive subsidiary of electronics increases. In contrast, safety and reliability of electronic devices, also draw much attention and concern. The purpose of this thesis is to explore safety and reliability of the power window anti-pinch system. This thesis uses the C language in programming, and is programmed into a microprocessor Microchip PIC16F1827 in a power window to achieve anti-pinch. The power window motor drives the rotation of the axis center. N pole and S pole contained in each of two Hall sensors generate pulse signals. The pulse signals are used to determine positions of the power window up or down, and the time interval is calculated to set the threshold pulse of anti-pinch. A finite state machine determines whether the window is automatic or manual control and the state transition controls the state of the window: up, down, or anti-pinch. In order to avoid misjudging the anti-pinch, the anti-pinch mechanism is set by a parametric method and is only triggered when the window rises in the anti-pinch zone and the pulse signal exceeds the threshold pulse for three times or the specified timeout of the Hall sensor signal expires.