基于PLL的高灵敏度自校准液面检测系统设计  

Design of high sensitivity and self calibration liquid level detection system based on PLL

作　　者：刘雄[1] 林茂松[1] 梁艳阳[1] 

机构地区：[1]西南科技大学特殊环境机器人技术四川省重点实验室,四川绵阳621010

出　　处：《微型机与应用》2014年第24期31-34,共4页Microcomputer & Its Applications

基　　金：国防技术基础研究项目(科工计[2011]869号);四川省教育厅青年基金项目(10zd1135)

摘　　要：针对高速医疗检测仪器对高灵敏和较强自适应能力的需求,提出一种基于PLL的自校准液面检测系统设计。该设计首先通过PLL电路将探针电容的变化转换为电压的变化,然后采用自校准算法调节PLL芯片VCIN的静态工作电压,最后结合自适应检测算法实现液面检测功能。实验表明,该液面检测系统中MCU输出的液面检测信号与检测电路产生的输出信号之间的延迟约为1.6 ms;同时能兼容样本针与试剂针液面检测系统,且所有探针的插入液面深度最大误差仅为0.37 mm,满足全自动生化分析仪的临床检验要求。The high-speed medical testing equipment requires highly sensitive and strong self-adaptive capabilities. A PLL- based self-calibration liquid level detection system is proposed. The design uses a PLL circuit to convert the change of probe＇s capacitance to the change of voltage, and then adopts a self-calibration algorithm to adjust PLL chip＇s VCIN quiescent voltage, finally combines adaptive detection algorithm to accomplish liquid level detection. Experimental results show that the delay between the liquid level detecting signal generated by MCU and the output signal of the detecting circuit is about 1.6 ms. While the liquid level detection system can be designed to be compatible with sample probe and reagent probe, and the maximum error of the insertion depth under the liquid is only 0.37 mm, which could satisfy the clinical inspection requirements of the automatic biochemical analyzer.

关 键 词：PLL 高灵敏度 自校准 自适应 液面检测 

分 类 号：TP212[自动化与计算机技术—检测技术与自动化装置]