基于PIC16F876A單片機的超聲波測距儀

電子機電論文編號:JD763  論文字數(shù):6950,頁數(shù):20

目  錄

一、系統(tǒng)方案比較與選擇 4
方案一：利用分立模塊的超聲波測距儀 4
方案二：基于PIC16F876A單片機的超聲波測距儀 4
二、理論分析與計算 6
1、測量與控制方法 6
2、理論計算 6
三、電路與程序設(shè)計 7
1、檢測與驅(qū)動電路設(shè)計 7
2、總體電路圖 12
3、軟件設(shè)計與工作流程圖 14
四、系統(tǒng)調(diào)試 15
1 超聲波測距誤差分析 15
2 提高精度的方案及系統(tǒng)設(shè)計 16
3、測量結(jié)果 18
五、創(chuàng)新發(fā)揮 19
六、設(shè)計結(jié)論 20

摘要：電子測距儀要求測量范圍在0.10～5.00m，測量精度1cm，測量時與被測物體無直接接觸，能夠清晰穩(wěn)定地顯示測量結(jié)果。由于超聲波指向性強，能量消耗緩慢，在介質(zhì)中傳播的距離較遠，因而超聲波經(jīng)常用于距離的測量，如測距儀和物位測量儀等都可以通過超聲波來實現(xiàn)。超聲波測距器，可以應(yīng)用于汽車倒車、建筑施工工地以及一些工業(yè)現(xiàn)場的位置監(jiān)控，也可用于液位、井深、管道長度的測量等場合。利用超聲波檢測往往比較迅速、方便、計算簡單、易于做到實時控制，并且在測量精度方面能達到工業(yè)實用的要求，因此在移動機器人的研制上也得到了廣泛的應(yīng)用。
該測距儀采用NE555電路、兩級放大電路和電平比較電路實現(xiàn)了超聲波的發(fā)射與接收。單片機為該測距儀的核心單元，實現(xiàn)發(fā)射電路的控制和接收數(shù)據(jù)的處理。本系統(tǒng)在10～200cm的距離內(nèi)測量精度可達±0.5cm，并且易于調(diào)試，成本低廉，具有很強的實用價值和良好的市場前景。
    關(guān)鍵字：超聲波傳感器，測距儀，PIC16F876A

Abstract：Ultrasonic Ranging, can be used in car reversing, the construction site and the location of some industrial site monitoring, can also be used if the level, depth and length of the pipeline, such as measurement occasions. Measurement of the requirements in the 0.10-5.00 m, precision 1 cm, with the measurement of detected objects without direct contact, being able to clearly show stable measurement results. Because of the strong point of ultrasonic energy consumption slow, medium of communication in the longer distance, thus frequently used ultrasonic distance measurement, such as the range finder and level measurement and so on can be achieved by ultrasound. Use of ultrasonic testing is often more rapid, convenient and simple terms, easy to achieve real-time control, and measurement accuracy can meet the practical requirements of industry, in the mobile robot has been developed on a wide range of applications.
The range finder only NE555 circuit， two amplifier circuit and the level achieved a comparison of launching and receiving ultrasound. SCM range finder for the core elements for launching the circuit control and receive data processing. 10-200 cm in the system of distance measurement accuracy up to ± 0.5cm， and easy to debug， low-cost， with strong practical value and good market prospects.
Keywords: Ultrasonic sensors, range finder, PIC16F876A