基于单片机超声波测距系统的设计和实现的论文.doc

PAGE 基于单片机超声波测距系统的设计和实现 摘 要 近二、三十年,特别是近十年来，由于电子技术及压电陶瓷材料的发展，使超声检测技术得到了迅速的发展。超声波具有聚束、定向及反射、透射等特性。超声检测技术是利用超声波在媒质中的传播特性（声速、衰减、反射、声阻抗等）来实现对非声学量（如密度、浓度、强度、弹性、硬度、粘度、温度、流速、流量、液位、厚度、缺陷等）的测定。本文详细介绍了一种基于单片机的超声波测距仪。该系统以空气中超声波的传播速度为确定条件,利用反射超声波测量待测距离。在介绍了单片机性能和特点的基础上，分析了超声波测距的发展及基本原理，介绍了传感器的原理及特性。由此提出了系统的总体构成。然后简要介绍了利用Atmega8单片机设计测距仪的原理:单片机发出的超声波，通过换能器发射出去，遇到被测物体后反射回来，计算此超声波从发射出到接受的时间差从而得出被测物体到测距仪的距离。针对测距系统发射、接收、检测、显示部分的总体设计方案做了论证,给出了系统的硬件原理图和软件实现框图。 关键词 单片机； 超声波； 测距； AT89S51； CX20106A Abstract Past 20 or 30 years, especially the past 10 years, as electronic technology and the development of piezoelectric ceramic materials, ultrasonic testing technology for fast development. Ultrasonic a buncher, orientation and reflection, transmission, and other properties. Ultrasonic detection technology is used in ultrasonic propagation in the medium (velocity, attenuation, reflections, acoustic impedance, etc.) to achieve the volume of non-acoustic (such as density, concentration, strength, flexibility, hardness, viscosity, temperature, flow rate, flow , level, thickness, defects, etc.) were measured.The thesis introduces a kind of single-pulse-reflection ultrasonic distance meter system in detail based on single chip processor. The system could measure certain distance on the premise that the speed of reflected wave in the air is fixed. Based on the study of single chip processor, this paper summarizes the development and fundamental principle of ultrasonic detection. Then it presents the theory and characters of ultrasonic sensor. Moreover, it proposes the whole structure of the system by introducing the function of ultrasonic distance meter. Then this paper introduces the principle of distance一measuring一device which is designed with the single chip Processor of 51series. This principle is based on the ultrasonic measure which is calculated by the time used by ultrasonic traveling fro