【正文】 1 single chip machine and the corresponding digital circuit, by it, gather the signal of each sensor , decide and control the synthetic output of speech sound as a result according to handling and calculation. Because of the 8031 single chip machine without ＲＯＭ , expand a slice of ＥＰＲＯＭ 2764 is as the program memory. The system of speech sound with Japanese Dong Zhi pany39。 ｃ 檢測(cè)發(fā)動(dòng)機(jī)機(jī)油油量 。根據(jù)需要 ,在ＣＰＵ的控制下 ,要求能輸出以 下的提示語(yǔ)音 : ａ注意車(chē)門(mén)未關(guān) 。 ｊ酒后駕駛危險(xiǎn)。 在本設(shè)計(jì)中對(duì)車(chē)門(mén)、倒車(chē)檢測(cè)均采 用ＯＲＤ 226干簧片開(kāi)關(guān)傳感器。在汽車(chē)的后保險(xiǎn)杠兩端裝設(shè)超聲波發(fā)射/接收器 ,兩個(gè)發(fā)射 /接收器以均等時(shí)間的方式 ,依次發(fā)射 /接收超聲波 ,循環(huán)反復(fù)進(jìn)行。 系統(tǒng)通電后 ,主程序先完成初始化工作 ,包括設(shè)堆棧指針 ,設(shè)定定時(shí)器 /計(jì)數(shù)器的工作方式及初值 ,將有關(guān)存儲(chǔ)單元置初值 ,啟動(dòng)定時(shí)器 /計(jì)數(shù)器 ,開(kāi)中斷等等。 總結(jié) 利用各種傳感器 ,該系統(tǒng)可以檢測(cè)出多種危險(xiǎn)情況并及時(shí)發(fā)出語(yǔ)音報(bào)警 ,防患于未然 ,避免事故的發(fā)生 ,成為駕駛員安全行車(chē)的好幫手。 MCS51把微型計(jì)算機(jī)的主要部件都集成在一塊心片上，使得數(shù)據(jù)傳送距離大大縮短，可靠性更高，運(yùn)行速度更塊。 并行輸入輸出 (I/O)口： 8051共有 4組 8位 I/O口 (P0、 P P2或 P3)，用于對(duì)外部數(shù)據(jù)的傳輸。 中斷系統(tǒng)： 8051具備較完善的中斷功能，有兩個(gè)外中斷、兩個(gè)定時(shí) /計(jì)數(shù)器中斷和一個(gè)串行中斷，可滿足不同的控制要求，并具有 2級(jí)的優(yōu)先級(jí)別選擇。因此，在工業(yè)測(cè)控系統(tǒng)中，使用單片機(jī)是最理想的選擇。 第二篇： MCS51單片機(jī)特性 和結(jié)構(gòu) 8051是 MCS51系列單片機(jī)中的代表產(chǎn)品，它內(nèi)部集成了功能強(qiáng)大的中央處理器，包含了硬件乘除法器、 21個(gè)專(zhuān)用控制寄存器、 4kB的程序存儲(chǔ)器、 128字節(jié)的數(shù)據(jù)存儲(chǔ)器、 4組 8位的并行口、兩個(gè) 16位的可編程定時(shí) /計(jì)數(shù)器、一個(gè)全雙工的串行口以及布爾處 理器。例如 ,當(dāng)傳感器檢測(cè)到汽車(chē)正在倒車(chē)時(shí) ,ＣＰＵ選定要觸發(fā)的發(fā)射點(diǎn)地址 ,然后啟動(dòng)發(fā)射電路并開(kāi)始計(jì)時(shí) ,在給定時(shí)間內(nèi)如接收到信號(hào)則由延遲時(shí)間可以計(jì)算出障礙物到發(fā)射點(diǎn)的距 離。汽車(chē)距障礙物的距離是通過(guò)聲納發(fā)出到反射回來(lái)這段行程所花費(fèi)的時(shí)間來(lái)測(cè)定并進(jìn)行計(jì)算的 ,計(jì)算式 如下 : ｄ =12ｃｔｃ =331+0 6θ 式中 ｄ ——— 汽車(chē)距障礙物的距離 ｃ ——— 超聲波在空氣中傳播的速度 ｔ ——— 測(cè)定的時(shí)間 θ ——— 車(chē)外空氣溫度角 聲納可測(cè)得的障礙物大約在 50ｃｍ范圍以?xún)?nèi) ,當(dāng)障礙物距汽車(chē)不到 50ｃｍ時(shí) ,發(fā)出語(yǔ)音報(bào)警。 對(duì)發(fā)動(dòng)機(jī)機(jī)油油量和制動(dòng)油油量的檢測(cè)均采用ＣＥ 415型浮子 簧片液位傳感器。 系統(tǒng)硬件 為完成上述的各項(xiàng)檢測(cè)及語(yǔ)音輸出要求 ,本系統(tǒng)采用如圖 1所示的硬件結(jié)構(gòu)。 ｃ機(jī)油油量不足 。 ｅ 汽車(chē)倒車(chē)時(shí) ,檢測(cè)車(chē)后障礙物情況 。s cab reaches certain density, sends a alarm signal to the single chip microputer. When automobile back a car , system uses the barrier of supersonic detection vehicle rear. The rear bumper two ends of automobile pack to set up supersonic project/receiver, two project/receiver with the way of equal time, project/in proper order to take over supersonic , is circulating to go on again and again. Because of this cycle time is from ＣＰＵ control, therefore this system will not get the wrong signal influence from external sound wave. Automobile distance the distance of barrier is pass through sonar send reflection return the time that this route spends e to survey and calculate , calculation has following type. ｄ =1/2*ct ｃ =331+ In type ｄ — — — automobile far from the distance of barrier ｃ — — — supersonic the speed that propagated in air ｔ — — — the time of mensuration θ — — — vehicle outside air temperature Angle sonar the barrier that can be measured approximate in 50ｃｍ scope within, pawn barrier distance automobile do not go to 50ｃｍ , send speech sound to report to alarm. On the road surface that the moist of rainy day or ice snow covers , between road surface and wheel tyre, coefficient of friction is little , vehicle is all right with high speed or sudden braking makes automobile overturn easily, which knows vehicle course Central Africa, is frequently dangerous. Therefore in this system spoil frequently some point using driver in the course of traveling to move brake movement, detection tyre and the slip rate of road surface ( racial of drive wheel and the bad speed of rotational speed of undrive wheel of drive wheel), and the accordingly estimation condition of road surface. And beg the specific practice of slip rate is the sensor of rotational speed of edd current installation in drive with undrive wheel on, measure the difference of rotational speed , so making slip rate finally in order to remind that driver 4 reduces speed. softwares The main program block diagram shows as . The subprogram of speech sound shows as . After system starts eclectricity , main program first plete initialization work includes setting up storehouse indicator , sets initial value and the working way of timer/counter, put relevant storage element initial value, start timer/counter