摘 要:本文介紹了一種基于三次樣條插值的真空測(cè)量非線性校正方法,討論了三次樣條插值函數(shù)的建立及在計(jì)算機(jī)系統(tǒng)上的實(shí)現(xiàn),對(duì)插值結(jié)果進(jìn)行了分析,最后將結(jié)果以表格方式存入到飛思卡爾單片機(jī)的Flash中,在單片機(jī)程序中采用查表方法獲取相應(yīng)的校正函數(shù)。結(jié)果表明該方法具有精度高、速度快等特點(diǎn),具有良好的推廣應(yīng)用價(jià)值,是切實(shí)可行的。
關(guān)鍵詞:真空測(cè)量 非線性校正 樣條插值 傳感器
[b][align=center]Nonlinear Compensation of Thermocouple Circular Canal Sensor in the
Vacuum Measurement
Dong Chuangang, Sun Tongjing[/align][/b]
Abstract:A method of nonlinear compensation of vacuum measurement based on cubic spline interpolation is presented in the paper. The establishment of cubic spline interpolation function and the implement on the computer system is discussed, and interpolation result is analyzed in the paper. Finally the result is saved in the way of table into the Flash of Freescale MCU. The relevant compensation function is obtained by the method of table in the program. The results show that the method has the traits of high precision and quick rate, and has well value to be extended and is feasible.
Key words:vacuum measurement; nonlinear compensation; spline interpolation; sensor
0 引言
熱偶規(guī)是用來測(cè)量氣體負(fù)壓的一種傳感器,它是利用氣體的熱傳導(dǎo)現(xiàn)象來測(cè)量氣體壓強(qiáng)的。當(dāng)熱偶規(guī)在定流方式下工作時(shí)給熱偶規(guī)熱絲通入一恒定電流,由熱電偶測(cè)量熱絲的溫度,壓強(qiáng)高時(shí)氣體導(dǎo)熱性能好,熱絲散走的熱量多,所以熱絲溫度低;壓強(qiáng)低時(shí)氣體導(dǎo)熱性能下降,熱絲溫度高,將熱電偶輸出的毫伏數(shù)轉(zhuǎn)換為壓強(qiáng)值就實(shí)現(xiàn)了真空度的測(cè)量。測(cè)量過程中壓強(qiáng)值是熱電偶輸出毫伏值的函數(shù)p=f(v),v是熱電偶輸出值,p是壓強(qiáng)值。
由于熱電偶傳感器輸出信號(hào)電壓v與被測(cè)參數(shù)氣壓p之間存在著明顯的非線性,且不可用一簡(jiǎn)單的數(shù)學(xué)式來描述,為了提高測(cè)量精度,必須對(duì)非線性特性進(jìn)行校正,使之線性化。線性化處理的方法,常用的有兩大類:硬件線性化和軟件線性化。在有微機(jī)參與的系統(tǒng)中,為了節(jié)省硬件投資,簡(jiǎn)化系統(tǒng)結(jié)構(gòu),常取軟件方法。本文采用的是三次樣條插值法。
詳情請(qǐng)點(diǎn)擊:
真空測(cè)量中熱偶規(guī)傳感器的非線性特性校正