【作者】 郭宏亮；

【导师】 秦建敏；

【作者基本信息】 太原理工大学 ， 检测技术与自动化装置， 2007， 硕士

【摘要】 近年来极地冰川和内陆高原冰川消融幅度比较大，另外，我国北方地区的大河、大江都存在着不同程度的凌汛问题。要了解冰川融化和冰凌的发生，就离不开对冰层厚度的测量。鉴于此本文提出了利用空气、冰、水的电容差异测量冰层厚度的新方法。通过大量的实验结果分析发现三者电容值存在数量级上的差异，可以将测得的电容值转化为频率或者数字信号，由于电容值存在数量级上的差异，那么在传感器逐点测量中，如果有频率或者数字信号的跳变，就说明是测量的介质由一种变为了另外一种。只要测出两次这样的跳变，那么就可以分辨出冰层的上界面和下界面了，上下界面之差就是冰层厚度了。以下简要介绍了整个系统的设计。在本文中主要介绍了测量冰厚的电容传感器的结构，电容转换为频率或者数字信号的信号调理电路，数据处理电路及上位机的显示与处理。电容传感器结构是由按照等间隔排列的多组平板电容组成，内部设计了每个电容的选通电路。信号调理电路设计了三种调理方式：一种是采用专用芯片AD7745实现电容直接转换为24位数字信号；另外两种采用了不同的振荡电路实现电容向频率的转换。在信号调理电路中还完成了接受采集指令进行数据采集以及向数据处理电路发送采集数据。数据处理电路是以单片机为核心包括时钟、存储、通讯等的电路。时钟电路不仅提供了测量的实时时间，而且产生一分钟一次的中断信号用于单片机向信号调理电路发采集指令。由于在数据传送中有可能会丢失或者传输错误，也有可能上位机没有实时的接收数据，所以设计了存储数据电路以便日后补测数据。上位机的显示与处理程序中包括了数据存储、数据分析处理及显示实验数据得出冰层厚度。通讯主要有三种方式：第一种方式是利用串口与上位机通讯，适合近距离的数据传输；第二种方式是利用RS232转CAN总线实现数据远传和多个传感器的联网控制；第三种方式是通过GPRS／GSM模块实现数据的远传。更多还原

【Abstract】 In recent years, extent of the polar glacier and the inland plateau glacier melt is comparatively big , great river , great river all exist ice run problem in north area of our country besides. Essential acquaintance glacier thawing and occurrence of icicle will be not to get away to measure thickness of ice layer. According to this ,the new method of measuring ice layer thickness has been put forward on the base of the difference of air、ice、water capacitance in this thesis. All that Capacitance values of three medium exist difference of order of magnitude were discovered by the fact that large amount of experiment result analysis, capacitance value measured can be changed into digital signal or frequency that the single chip may measure, since capacitance value exists upper difference of order of magnitude, when the sensor is measured point-by-point ,show being that the measuring medium has become another one kind from one kind if frequency sprung, As long as Change is measured out twice such springing, so (we) can resolve upper and down interface of ice layer, difference of interface is thickness of ice layer. The following will introduce entire systematic design concretely.(We) have introduced the structure of capacitance sensor of measuring the ice thickness mainly in the main body of the thesis, the adjusting circuit of frequency or digital signal changed by capacitance, data handling circuit and display and process of upper machine. Capacitance sensor structure is composed of the multiunit flat capacitance arranged according to the same gap, design selection circuit of every capacitance inside. Signal adjusted circuit has designed three kinds of adjusting way: One kind is that the reality of changing capacitance into frequency adopt special chip AD7745; adopt the different oscillating circuit to realize capacitance changing into frequency besides two kinds. It completes acquisition direction and runs to collect data in signal adjusting circuit and sends collecting data to the circuit of data process. The data handling circuit is the circuit taking single chip as core including clock、memory, communication etc. Not only clock circuit provides ’ the real time for measurement, but also the interruption signal producing one time of a minute is used to be that single chip sends the collection instruction to signal adjusting circuit. Since data transfer can have a mistake or possibly be lost in sending data, also possibility upper machine does not accepting data in real time, therefore the data circuit having designed memory can be used to make up data in the future. The displaying and disposing program of upper machine is composed of data memory、data analysis and process and display of reaching the ice layer thickness according to experiment data. Communication has three kinds way mainly: The first kind of way is the communication making use of serial port and upper machine, is suitable to the close quarter data transmission; second kind of way is Be that making use of RS232 to CAN bus realizes distant transmission of data and many sensor networking control; Third kind of way is that the distant sending data is realized by the GPRS/GSM module.更多还原