研究智能氣體檢測(cè)系統(tǒng)外文翻譯-其他專業(yè)-展示頁(yè)
2025-01-31 03:01本頁(yè)面
【正文】 系列單片機(jī)匯編程序語(yǔ)言包括主程序，鍵盤(pán)掃描程序， A/D轉(zhuǎn)換程序，報(bào)警程序，串口通訊程序，數(shù)據(jù)顯示程序，系統(tǒng)報(bào)警診斷程序，雙字節(jié)乘法程序，三字節(jié)二進(jìn)制程序看狗程序。主程序初始化單片機(jī)寄存器， I / O 端口，然后掃描鍵盤(pán)看數(shù)據(jù)采集鍵被按下，如果沒(méi)有 ，繼續(xù)掃描鍵盤(pán)按鍵直到數(shù)據(jù)收集。當(dāng)按下 Enter 鍵，系統(tǒng)開(kāi)始數(shù)據(jù)采集的運(yùn)行和 A / D轉(zhuǎn)換，然后將轉(zhuǎn)換后的數(shù)據(jù)為二進(jìn)制格式調(diào)用一個(gè)子程序的雙字節(jié)乘法。接下來(lái)，系統(tǒng)會(huì)將這些二進(jìn)制格式的數(shù)據(jù)轉(zhuǎn)換成二進(jìn)制編碼的十進(jìn)制格式，通過(guò)調(diào)用一個(gè)子程序三字節(jié)的二進(jìn)制編碼的十進(jìn)制。在這期間， 這些數(shù)據(jù)將被發(fā)送到上位機(jī)通過(guò) RS485串行地通信單元。本系統(tǒng)采用單片機(jī)的晶振頻率為12MHz，與定時(shí)器 /計(jì)數(shù)器，模式 1的工作（ 16位定時(shí)器 /計(jì)數(shù)器），其最大時(shí)間間隔約為 66ms，所以系統(tǒng)會(huì)發(fā)送一個(gè)信號(hào)到喂狗看門(mén)狗電路各 66ms。它可以用于實(shí)時(shí)甲烷氣體濃度監(jiān)測(cè)。它具有速度快、高性能的 12位 A / D轉(zhuǎn)換器，工作環(huán)境溫度范圍從 20℃ ～ + 70℃ 。在本文中，總規(guī)劃軟件和氣體檢測(cè)系統(tǒng)的硬件設(shè)計(jì)提出了利用 Proteus，測(cè)試硬件電路，采用 KEIL測(cè)試組裝語(yǔ)言源程序，仿真試驗(yàn)結(jié)果表明該系統(tǒng)具有較高的精度，快速響應(yīng)是可行的。 emitting sound and light alarm signals if the CH4 concentration value is beyond the alarm value inputted by keyboard panel。 the overall schematic diagram of system is shown in Figure 1. The reason for selecting singlechip microputer as a control core is that it possesses advantages of small size, high reliability, low price which made it very suitable to be used in industries of intelligent instrument and real time control . The operating interface of system is shown in Figure 2. Number at upper right corner shows the default or userdefined gas concentration value, number at upper left corner shows detected gas concentration value. One alarm lamp is equipped. All functions are controlled by keys arranged on the control panel, including POWER key, RESET key, DATA COLLECTION key. Other keys including ten number keys, ADJUST VALUE key and ENTER key are used to change threshold values. Basic operating procedures are as follows: Firstly press POWER key, the system initialized. Press DATA COLLECTION key, LED at upper right corner displays the threshold value 。 second one is the performanceprice ratio of the the aforementioned factors, we adopted the AT89S52 developed by ATMELas main control unit, and the final scheme of main control circuit consists of AT89S52, timer and reset circuit [8,9]. As shown in figure Sensor Selection A crucial issue in gas detecting system design is how to select gas sensors. Common gassensors are metal oxide semiconductor such as tin oxide, zin coxide, titanium oxide andaluminum oxide. Problems encountered with these sensors are lack of flexibility, poor response times and operated at elevated temperature [10]. A new method of ch4 detecting based on infrared techniques was presented in recent years, but it is still in progress and much work should be done before it can be applied to solve the practice problems [11]. This system adopted catalytic bustion type gas sensor MC112 developed by SUNSTAR group to measure the gas (ch4) concentration. Figure 4 shows the outside view and internal circuit of MC112, table 1 lists the main technology parameters of MC112. MC112 gas detector exploits catalytic bustion principle。 (3)low power consumption, largescale operation voltage, good linearity, good thermal stability and high reliability. The schematic diagram of signal amplifier circuit is shown in figure 5. A/D Converter Module As shown in Figure 6, this module consists of multiplexer CD4051, sampling holder LF389, A/D converter AD574A[12] and parallel I/O chip 8255A. As a core part, AD574A is a 1
畢業(yè)設(shè)計(jì)相關(guān)推薦
鄂ICP備17016276號(hào)-1