多路铂电阻无线测温系统的设计

多路铂电阻无线测温系统的设计(论文14000字)
摘要：针对常用的两线制电阻测温误差大、单点测温探测范围有限等问题，本文提出一种以PT100铂电阻为传感器的多路四线制无线测温系统。系统主要由微控制器、激励电流源、PT100传感器、信号调理电路、无线收发、TFT屏显示、信息存储等模块构成。传感器采用四线制接法以减小导线电阻对测量的影响。设计恒流源作为激励，将电阻量转换为电压信号，输入微控微器内部ADC采样，计算电阻值并根据PT100阻值和温度的函数关系，换算成温度值。各路测量结果通过无线模块发送到主机，主机驱动TFT屏显示测量信息，并通过串口发送到上位机。采用LabVIEW编写了上位机显示界面。论文提出了电路原理图和软件设计流程，并进行了实验调试。测试时，先采用PT100传感器测量温度，检查系统功能。为测试系统精度，利用特定阻值（对应不同温度）的UPRN型高精度、低温漂电阻（精度万分之一，温漂2PPM）以四线制接入到系统中，测量结果表明，温度测量精度可达到±0.25℃，且能可靠地无线发送到终端。
关键词：PT100；温度测量；无线传输；四线制
 
Multi-channel platinum resistance wireless temperature measurement system
Abstract：Aiming at the common two-wire resistance temperature measurement error and limited single-point temperature detection range, this paper proposes a multi-channel four-wire wireless temperature measurement system with PT100 platinum resistance as the sensor. The system is mainly composed of a microcontroller, an excitation current source, a PT100 sensor, a signal conditioning circuit, a wireless transceiver, a TFT screen display, and an information storage module. The sensor uses a four-wire connection to reduce the influence of the wire resistance on the measurement. The constant current source is designed as an excitation, and the resistance is converted into a voltage signal, which is input into the micro-controller's internal ADC. The resistance is calculated and converted into a temperature value according to the function of the PT100 resistance and temperature. Each measurement result is sent to the host through the wireless module. The host drives the TFT screen to display measurement information and send it to the host computer through the serial port. Using LabVIEW to prepare the host computer display interface. The paper put forward circuit schematics and software design flow, and conducted experimental debugging. During the test, the PT100 sensor was used to measure the temperature and check the system function. To test the accuracy of the system, use a UPRN type high precision, low temperature drift resistance (with one thousandth of precision, temperature drift 2PPM) with specific resistance (corresponding to different temperatures) to access the system in a four-wire system. The measurement results show that the temperature measurement Accuracy can reach ± 0.25 °C, and can be wirelessly transmitted to the terminal reliably.
Keywords：PT100; Temperature measurement; Wireless transmission; Four-wire system
 

目 录
1 绪论    1
1.1 课题的研究目的及意义    1
1.2 课题的国内外研究现状    2
1.2.1 测温元件的类型    2
1.2.2 多点测温的意义    2
1.3 论文内容简介    2
1.4 本章小结    3
2 系统总体设计方案    3
2.1 方案对比论证与器件选择    3
2.1.1 测量方案对比    3
2.1.2 激励电流源方案对比    5
2.1.3 信号调理电路方案对比    5
2.1.4 主从控制器对比    6
2.1.5 无线组网方案对比    6
2.1.6 显示方案对比    7
2.1.7 稳压方案对比    7
2.1.8 存储方案对比    8
2.2 总体方案    8
2.3 本章小结    8
3 系统硬件设计    8
3.1 四线制测量电路    8
3.1.1 四线制接口电路设计    9
3.1.2 恒流激励电流源设计    9
3.2 信号调理电路设计    10
3.3 微控制器最小系统    10
3.3.1 各测量子模块主控STM8S103最小系统    10
3.3.2 终端主控制器STC15最小系统    11
3.4 无线模块接口电路设计    11
3.4.1 NRF24L01与从机接口电路    12
3.4.2 NRF24L01与主机接口电路    12
3.5 单片机驱动液晶显示器    12
3.6 存储器接口电路设计    13
3.7 按键控制电路设计    13
3.8 系统从机总电路图    13
3.9 系统主机总电路图    14
3.10 本章小结    15
4 系统软件设计    15
4.1 软件应用开发平台    15
4.2 系统程序流程图    15
4.2.1 发射机程序流程图    15
4.2.2 接收机程序流程图    16
4.3 终端显示界面开发    17
4.4 本章小结    17
5 调试结果与分析    17
5.1 调试步骤    17
5.1.1 恒流源电路调试    17
5.1.2 铂电阻测温电路调试    18
5.1.3 无线传输模块调试    19
5.1.4 屏幕显示电路调试    19
5.1.5 存储功能模块调试    20
5.2 调试结果分析    20
5.3 调试中遇到的问题及解决方法    20
5.4 本章小结    20
6 总结与展望    20
6.1 论文总结    20
6.2 对设计的展望    21
参考文献    22
致谢    23
附录    24