斯特林制冷机A/D位数扩展与仿真分析

Stirling cryocooler A/D bit expansion and simulation analysis

为解决斯特林制冷机温控系统中A/D转换器采样精度较低对斯特林制冷机控温稳定性的影响,本文基于A/D转换原理,结合斯特林制冷机实际测温特点,提出一种提高A/D转换器采样精度的位数扩展方法,并基于simulink/matlab软件搭建斯特林制冷机温控系统仿真模型验证该扩展方法的有效性。结果表明:通过使用电阻逼近扩展法扩展A/D转换器的位数之后,线性斯特林制冷机冷头的温度波动范围变小,温度稳定性得到提高,说明了该A/D扩展方法理论思路的有效性。

In order to solve the influence of low sampling accuracy of A/D converter in the temperature control system of Stirling cryocooler on the stability of temperature,a bit expansion method was proposed to improve the sampling accuracy of A/D converter based on the principle of A/D conversion.Combined with the actual temperature measurement characteristics of Stirling cryocooler,a simulation model of temperature control system of Stirling cryocooler was builid based on Simulink/Matlab software and verified the effectiveness of the expansion method.The results show that the temperature fluctuation range of the cold head of the linear Stirling cryocooler becomes smaller and the temperature stability is improved after the bit number of A/D converter is extended by the resistive approximation extension method,which illustrates the effectiveness of the theoretical idea of the A/D ex⁃tension method.