基于STM32和CPLD的新型全自动量热仪研究与设计  

Research and design of new full⁃automatic calorimeter based on STM32 and CPLD

作　　者：魏丽君[1,2] WEI Lijun(School of Automation,Central South University,Changsha 410003,China;Hunan Railway Professional Technology College,Zhuzhou 412001,China)

机构地区：[1]中南大学自动化学院,湖南长沙410003 [2]湖南铁道职业技术学院,湖南株洲412001

出　　处：《现代电子技术》2022年第24期74-79,共6页Modern Electronics Technique

基　　金：湖南省教育厅科学研究项目(19B379)。

摘　　要：针对当前量热仪通信不够稳定、控制方式复杂、温度采样不精准、主期时间太长等问题,文中提出一种基于STM32硬件平台的新型自动量热仪的设计方案。整体设计时将下位机主控板和人机交互部分分开设计,简化控制方式;再采用SPI方式通信,提升通信的稳定度,采用高精密传感器PT1000进行采集温度,并对内外筒温度进行基线修正补偿,提高温度采用的精密度;最后,设计完善的A/D转换电路和微弱信号处理电路,最大限度地提高信噪比。另外,设计液晶显示模块和结果打印模块,以使人机交互界面更加友好。初期、主期、末期温度采集以及C值的算法严格按照国家标准执行,对设备按照瑞方法和国标法进行试验测试。结果表明:所设计自动量热仪主期时间控制到7 min,较之前水平提升近2 min;热容量相对标准差为0.06%,极差为15.42 J/K,发热量相对标准差为0.08%,极差为53.12 J/g。新型全自动量热仪人机交互更友好,主期时间缩短10.8%,试验效率得到极大提升,热容量、发热量相对标准差和极差的测试结果优于国家标准,说明该产品可量化试产。In allusion to the problems of unstable communication,complex control mode,inaccurate temperature sampling and too long main period of the current calorimeter,a design scheme of a new automatic calorimeter based on the hardware platform with STM32 is proposed.In the overall design,the main control board of the lower computer and the human⁃computer interaction part are designed separately to simplify the control mode,and SPI communication is used to improve the stability of communication.The high⁃precision sensor PT1000 is used for temperature acquisition,and the baseline correction and compensation for the temperature of the inner and outer cylinders is conducted to improve the precision of the applied temperature.The excellent A/D conversion circuit and weak signal processing circuit are designed to improve the signal⁃to⁃noise ratio to the maximum extent.The liquid crystal display module and result printing module are designed to make the human⁃computer interaction interface more friendly.The C value algorithm and temperature acquisition at the initial,main and final stages are strict in accordance with national standards.The equipment was tested according to Swiss method and international standard method.The results show that the temperature acquisition time in the main stage of the designed automatic calorimeter is controlled within 7 min,which is nearly 2 min less than the current level;when the relative standard deviation of heat capacity is 0.06%,the limit deviation is 15.42 J/K;when the relative standard deviation of calorific value is 0.08%,the limit deviation is 53.12 J/g.The human⁃computer interaction of the designed new full⁃automatic calorimeter is more friendly,its main period time is shortened by 10.8%,the test efficiency is greatly improved,and the testing results of relative standard deviation and limit deviation of heat capacity and calorific value are better than the national standard,which shows that the product can be trial⁃produced in batches.

关 键 词：全自动量热仪 SPI通信 电路设计 A/D转换 温度采集 温度补偿 试验测试 

分 类 号：TN876-34[电子电信—信息与通信工程] TP334.3[自动化与计算机技术—计算机系统结构]