摘要
针对传统乌式粘度仪测量数据操作性差、液位检测自动化程度有限的弱点,设计一种液位自适应判定乌氏粘度仪。通过分析粘度仪的测量原理,根据吸液液位检测信号特征,提出基于K-L散度的吸液液位自动判定方法。设定液位到达计时刻度线会存在一个标志点,首先利用K-L散度方法获取标志点所在的液位检测信号窗口,采用格罗布斯准则自动判定窗口中标志点的位置,然后根据标志点计算计时起点或计时终点;再通过计时时间差进行吸液过程的流速估计,完成吸液自动判定。结合嵌入式UCOSIII操作系统和em Win图形库设计粘度仪系统,在触摸屏交互界面上实现数据的实时输入与显示。应用与实验结果表明,该粘度仪满足国家粘度测试标准,重复性优于0.35%,测量误差优于0.1%,并能进行直观的触摸界面操作,仪器显示界面友好。
Aiming at the disadvantages of traditional Ubbelohde viscometer has poor data interoperability and limited automation,an adaptive liquid level determination Ubbelohde viscometer instrument is designed. By analyzing the viscosity measurement principle of Ubbelohde viscometer,a new method for automatic suction fluid level detection with K-L Divergence is developed,which is based on the feature of the liquid level. Setting there is a mark point when the liquid level is reached at timing point line. First,the liquid level detection signal window is acquired by K-L divergence method,the mark point is automatically determined by Grubbs criterion,then the start point and stop point are obtained and the flow velocity is estimated based on timing difference. By combining embedded UCOSIII operating system and em Win graphic library,Ubbelohde viscometer system is designed to realize input and real-time display in touch screen interface. All experimental results show that the instrument can reach the demands of the national standard,in which the repeatability is superior to 0. 35%,the measuring error is less than 0. 1%,and the instrument has intuitive touch operation,the interface is friendly.
出处
《电子测量与仪器学报》
CSCD
北大核心
2018年第5期151-158,共8页
Journal of Electronic Measurement and Instrumentation
基金
国家自然科学基金(51205127)资助项目
