电子分析天平双闭环测量方法  

Electronic analytical balance double closed-loop measurement method

作　　者：陈星燎 刘通 刘艺柱 房雪键 Chen Xingliao;Liu Tong;Liu Yizhu;Fang Xuejian(Intelligent Manufacturing College,Tianjin Sino-German University of Applied Sciences,Tianjin 300350,China)

机构地区：[1]天津中德应用技术大学智能制造学院,天津300350

出　　处：《电子测量与仪器学报》2022年第9期208-216,共9页Journal of Electronic Measurement and Instrumentation

摘　　要：电子分析天平普遍采用脉宽调制电流的方法来精密调节电磁力,工程上原始数据较难达到百万分度级精度。在分析了传统方法对测量精度影响因素后,设计了一种双闭环控制的改进脉宽调制电流电路,将PID控制电路和电流测量混合电路解耦,降低了PID参数整定难度,避免了求解机械传感器和平衡检测通道系统传输方程,提高了设备响应速度和测量精度。实验数据表明,在未进行非线性校正且只进行滑动平均滤波的情况下,31 g量程的电子分析天平初始测量数据标准偏差为2×10^(-5)g,达到百万分度级精度,较同样电路和传感器的原始220 g量程电子分析天平精度提升10倍以上。Electronic analytical balances generally use the method of pulse width modulation current to precisely adjust the electromagnetic force, and it is difficult to achieve a million-degree accuracy in engineering. After analyzing the influence factors of traditional methods on measurement accuracy, an improved pulse width modulation current circuit with double closed-loop control is designed, which decouples the previous PID control circuit and current measurement hybrid circuit, reduces the difficulty of PID parameter tuning and solving the difficulty of the system transmission equation of the mechanical sensor and balance detection channel, and improves the response speed and measurement accuracy. Experimental data show that, without nonlinear correction and only with moving average filtering, the original measurement data of an electronic analytical balance with a 31 g-range can achieve an accuracy of one million divisions with standard deviation of 2×10^(-5)g, which is ten times better than the original 220 g-range electronic analytical balance with the same circuit and sensor.

关 键 词：电子分析天平 脉宽调制 双闭环控制 恒流源分流 

分 类 号：TH715.116[机械工程—测试计量技术及仪器] TN431.1[机械工程—仪器科学与技术]