基于数字闭环控制的宽量程复合真空计研究与设计

发布时间：2018-06-10 00:21

本文选题：复合真空计 + 模糊PID　；参考：《东南大学》2016年硕士论文

【摘要】：复合真空计是用于测量真空度的工具之一,其性能指标将直接影响科研、生产任务的完成质量。随着科学技术的发展,进一步提高真空计测量指标与数字化程度,具有一定的研究意义和实用价值。论文目的是研究与设计一种由电离规和电阻规复合的宽量程真空计。文章主要对直接影响高真空测量指标的稳定发射电流控制、离子流检测电路展开研究。首先明确高真空测量对电离规发射电流稳定的需求指标,结合被控对象特征,进行了常用控制算法在稳发射电流应用中的可行性分析,在此基础上,重点讨论了参数模糊自整定PID算法控制发射电流稳定的原理,对其功能进行仿真分析,并在单片机平台上实现了发射电流的数字闭环稳定控制。其次在对离子流信号的产生机理、检测影响因素进行分析后,选取基于T型电阻网络的改进型I-V转换法作为离子流信号检测方案,电路跨阻增益可切换、并对信号进行多级滤波以抑制噪声,使电路能够覆盖检测从皮安到微安的6个量级电流信号。复合真空计测试从稳定发射电流、离子流信号检测功能模块电路和系统整机三个方面进行。结果表明,离子流信号测量范围1pA～6uA,测量分辨率0.2pA,噪声小于1.5mV；电离规发射电流、加速极、阴极对地电位示值误差及时间稳定度均小于±0.8%；电阻规1Pa-103Pa主要测量范围内,示值误差不超过±10%；电离规10-8Pa-10-1Pa测量范围内,等效离子流法测试示值误差不超过±1%。测试结果符合JBT10074-2004、JBT7463-2005等现行国家标准规定,能够满足一般工业生产及科学研究中的真空测量要求。
[Abstract]:A compound vacuum meter is one of the tools used to measure the vacuum degree. Its performance index will directly affect the quality of the research and production tasks. With the development of science and technology, it is of great significance and practical value to further improve the measurement index and digital degree of the vacuum meter. The purpose of this paper is to study and design a kind of ionization gauge and the design of a kind of ionization gauge. A wide range vacuum gauge combined with a resistance gauge. The article mainly studies the stable emission current control which directly affects the high vacuum measurement index and the ion flow detection circuit. First, the requirement of the high vacuum measurement for the stability of the ionization gauge is determined, and the common control algorithm is applied to the stable emission current in combination with the characteristics of the controlled object. On the basis of the feasibility analysis, the principle of parameter fuzzy self-tuning PID algorithm to control the stability of the emission current is discussed, and its function is simulated and analyzed, and the digital closed loop stable control of the emission current is realized on the single chip platform. Secondly, after the analysis of the mechanism of the ion flow signal and the analysis of the influencing factors, the selection of the influence factors is selected. An improved I-V conversion method based on T type resistance network is taken as an ion flow signal detection scheme. The circuit cross resistance gain can be switched and multistage filtering is used to suppress the noise. The circuit can cover 6 magnitude current signals from Pico to micro safety. The composite vacuum meter tests the function of the stable emission current and the ion flow signal detection function. The results show that the measurement range of the module circuit and the system is carried out in three aspects. The results show that the measurement range of the ion flow signal is 1pA to 6uA, the measurement resolution is 0.2pA, the noise is less than 1.5mV, the emission current of the ionization gauge, the acceleration pole, the indication error of the cathode to ground potential and the time stability are less than + 0.8%, and the indication error is not more than 1 within the main measuring range of the resistance gauge 1Pa-103Pa. 0%, within the measurement range of the ionization gauge 10-8Pa-10-1Pa, the measurement error of the equivalent ion flow method is not more than + 1%.. The test results are in accordance with the current national standards such as JBT10074-2004, JBT7463-2005 and so on. It can meet the requirements of the vacuum measurement in the general industrial production and scientific research.
【学位授予单位】：东南大学
【学位级别】：硕士
【学位授予年份】：2016
【分类号】：TB772

【参考文献】