多项式拟合在分布式CAN总线测温系统中的应用  

Application of Polynomial Fitting in Distributed CAN Bus Temperature Measurement System

作　　者：王闯[1] 任勇峰[1] 李辉景[1] 

机构地区：[1]中北大学仪器科学与动态测试教育部重点实验室,电子测试技术重点实验室,山西太原030051

出　　处：《仪表技术与传感器》2016年第4期94-97,共4页Instrument Technique and Sensor

摘　　要：针对温度测量中测温点多且分散,设计了一种使用CAN总线的分布式测温系统。使用PXI机箱接收采集数据,实现了4台温度采集设备接入CAN总线网络,能够实时监测测温点温度变化情况。为了减小热电偶非线性对采集精度的影响,在使用冷结补偿措施外,提出了一种使用六次多项式拟合的方法对采集系统进行标定,相对于常用的线性拟合,减小了系统的测量误差。实验结果表明：该测温系统在其测量范围-40～1200℃内,最大测量误差1‰F.S,具有广泛的应用价值。A distributed temperature measurement system using CAN bus was designed for the multi-point and dispersion in temperature measurement. PXI chassis was used to achieve the acquired data,it realized four temperature acquisition devices to access CAN bus network and real-time monitoring of temperature changes at temperature measured point. To reduce the thermocouple nonlinear effect on the acquisition precision,using measures besides cold junction compensation,a method of using six order polynomial fitting to calibrate the acquisition system was proposed. To be compared with the commonly used linear fitting,the measurement error of the system was reduced. The experimental result shows that the maximum measurement error is 1 ‰ F. S over the measuring range- 40 ～ 1200 ℃ of the temperature measurement system,thus it has wide application value.

关 键 词：CAN总线 分布式测温系统 冷结补偿 多项式拟合 错误界定 标定 

分 类 号：TP274[自动化与计算机技术—检测技术与自动化装置]