摘　　要
本文設計的汽車電動車窗自適應控制系統(tǒng)采用司機主控面板和乘客子控面板雙控制的方式來控制車窗的關閉和開啟。為了充分保障司機對整車的控制權，主控面板的控制級別要高于分控制面板的控制。系統(tǒng)設有防夾功能，當車窗上升過程中遇到障礙物無法前進時會自動停止上升并下降一定幅度，并等待下次指令發(fā)出。此外為了滿足突發(fā)情況發(fā)生時乘客強行關窗的需要，在司機主控面板處設有強行關窗指令按鍵，此時將忽略防夾功能進行強行關窗。系統(tǒng)對車內空氣實時監(jiān)測，對煙霧、酒精、丙烷等有害、可燃或其他危及車內人員身體健康或人身安全的氣體進行檢測，當此類氣體達到一定濃度后會自行開窗通風。為了防止汽車高速行駛時發(fā)生意外，在高速行駛時會自動關窗并上鎖，此時只有司機處的主控開關能夠控制車窗開啟。
該電動車窗自適應控制系統(tǒng)線路比較簡單，為了節(jié)省成本同時為了便于維護和升級本系統(tǒng)采用獨立控制模式。采用AT89C52單片機作為主控器進行指令采集、運算分析、車窗動作控制和障礙物判斷等；采用鍵盤掃描的方式采集指令節(jié)省線路的同時節(jié)省控制器的接口資源；采用LM298驅動芯片結合光柵對車窗升降電機進行驅動和閉環(huán)控制，并實現(xiàn)障礙物判斷；采用MQ-2氣體傳感器對車內空氣檢測并在濃度過高時觸發(fā)主控器進行控制操作。
本設計具有線路簡單、易實現(xiàn)、功能全和可維護性高等特點，并通過實物演示可知本文設計的系統(tǒng)可以完整的實現(xiàn)預設功能。

Abstract
The design of the adaptive control car windows system in this paper using two control panel —the driver’s master control panel and passenger sub-control panel to control the closing and opening of windows. In order to fully guarantee the driver’s control power of the car, the control level of the main control panel is higher than the level of sub-control panel. The system is equipped with anti-trap function, the car window will stop rise and decline a certain range if encounter to obstacles when the car window is during the ascent and whit the next command. And in addition , the need of force closing of the window in some emergence situation, the system also with an button of force close command in the driver’s main control panel, in this situation system will ignore the obstacle to force rise. System real-time monitoring of the air inside the vehicle, detection the gas of alcohol, methane and other harmful, flammable or other endanger the body health or safety of personnel inside the vehicle. The windows will open to ventilate when these harmful gas reaches a certain concentration. In order to prevent accidents when the car is in the process of high speed, windows will be closed and locked in the process. At this time , only the driver’s main control panel can control the windows .
This system’s circuit is simple. In order to save costs and facilitate the maintenance and upgraded, this system with independent control mode. The AT89C52 microcontroller as a master instruction acquisition, operational analysis, windows motion control and obstacle judge; Keyboard scanning to acquisition instruction in order to reduce lines at the same time saving interface resources; LM298 driver chip combined with the grating on the window lift motor drive and closed-loop control; Using the MQ-2 gas sensor for detection of air inside the vehicle and in the concentration is too high to trigger the master control operations.
The design is Simple circuit, Easy to implement and Maintainability. The design of the system In this paper can complete default features through in-kind demonstration shows.

目　　錄
摘　　要 1
Abstract 2
引　　言 1
1 設計方案 2
1.1 方案及功能概述 2
1.2 方案論證 3
1.2.1 升降和特殊功能按鈕連接方案 3
1.2.2 車窗完全關閉和完全打開判斷方案 4
1.2.3 防夾功能實現(xiàn)方案 4
1.2.4 車窗電機驅動方案 4
1.2.5 室內空氣檢測方案 5
1.2.6 主電源斷電檢測方案 5
1.3 器件的選型 5
1.3.1 單片機選型 5
1.3.2 電機驅動芯片選型 5
1.3.3 氣體檢測傳感器選型 6
2 系統(tǒng)主要器件介紹 7
2.1 主控器STC89C52單片機介紹 7
2.1.1 STC89C52單片機主要引腳介紹 8
2.1.2 STC89C52單片機主要特性 11
2.2 L298N驅動芯片介紹 12
2.3 LM393電壓比較器介紹 16
3 硬件設計 18
3.1 電動車系統(tǒng)總體硬件組成 18
3.2 系統(tǒng)各模塊的設計 18
3.2.1 單片機系統(tǒng)電路設計 18
3.2.2 鍵盤掃描電路設計 19
3.2.3 電機驅動模塊的設計 20
3.2.4 脈沖防夾檢測模塊的設計 21
3.2.5 空氣檢測模塊的設計 22
3.3 系統(tǒng)硬件實物圖 22
4 系統(tǒng)軟件設計和算法實現(xiàn) 25
4.1 單片機開發(fā)軟件Keil介紹 25
4.2 程序設計思想和流程圖 26
4.2.1 整體程序控制流程 26
4.2.2 自適應障礙物判斷程序 28
4.2.3 電機控制程序 29
4.2.4 一鍵關窗上鎖功能程序 30
4.3 重要控制模塊的實現(xiàn)程序 31
4.3.1 指令識別與判斷 31
4.3.2 電機驅動程序 32
4.3.3 特色功能實現(xiàn)程序 33
5 系統(tǒng)調試 36
5.1 指令識別模塊調試 36
5.2 空氣檢測模塊調試 36
5.3 PWM控制電機速度調試 36
5.4 系統(tǒng)聯(lián)調 37
5.5 調試過程中遇到的問題 37
結　　論 38
參 考 文 獻 39
附錄A 系統(tǒng)其他主體程序補充 41
致　　謝 45