at89s52单片机控制的智能型金属探测器 学位论文.doc

目录 摘 要 1 ABSTRACT 2 第一章 绪论 3 1.1选题的意义 3 1.2国内外研究现状及存在问题 3 1.3设计的基本思路 4 第二章 分析探测金属的理论依据 5 2.1线圈介质条件的变化 5 2.2 涡流效应 6 第三章 硬件电路设计 7 3.1系统组成 7 3.2硬件电路功能描述 8 3.3整机工作原理描述 28 第四章 系统软件设计 29 4.1软件设计思想 29 4.2数字滤波及算法说明 30 4.3主程序流程图 31 4.4主要子程序模块设计 32 第五章 主要技术指标分析 42 总结 43 致谢 44 参考文献 45 附录 46 摘 要 木文着重介绍了一种基于AT89S52单片机控制的智能型金属探测器的硬件组成、软件设计、工作原理及主要功能。该金属探测器以AT89S52单片机为核心，采用线性霍尔元件UGN3503作为传感器，来感应金属涡流效应引起的通电线圈磁场的变化，并将磁场变化转化为电压的变化，并与设定的电压基准值相比较后，判定是否探测到金属。系统软件采用汇编语言编写。在软件设计中，采用了数字滤波技术消除干扰，提高了探测器的抗干扰能力，确保了系统的准确性。此外，文中还对影响金属探测器的灵敏度与稳定性的因素进行了探讨，仪器的工作频率、检测线圈的尺寸及匝数等是影响灵敏度的主要因素；而应用现场的环境温度、湿度及线圈的制作工艺和供电电源的稳定程度是仪器稳定性的影响因素。 关键词：单片机；金属探测器；线性霍尔元件 ABSTRACT This paper describes the composition of hardware and software,working principles and the functions of an intelligent metal detector which mainly consists of AT89S52 single Chip Micyoco and linear Hall-Effect Sensor. The equipment adopts UGN3503U linear hall-effect sensor as probe to detect the magnetic field change of the centre of a search coil resulted from eddy current effect and turn this magnetic field change into voltage change. The SCM measures the peak value of voltage and compares it with reference voltage. The determine whether detect metal or not. In case of detection of metallic mass,the Metal Detector provides an acoustical and optical alarm. The systems software adopts the assembler language to be written. Inside the software,the digital filter technology is utilized to eliminate the jamming. So the stability of system and the measuring veracity are improved. The effect of all factors on sensitivity and stability of Metal Detector are discussed in this paper. It is concluded that the operating frequency,the size of the search coil and turns are the main factors effected on the sensitivity of the instrument,the environment temperature and humidity in site,the winding technology of coils and the stability of power supply are the factors effected on stability of instrument. KEYWORDS:SCM (Singl