基于红外技术的薄膜厚度在线测量系统研究
发布时间：2019-02-15 14:34
【摘要】：在薄膜生产和加工中,实现对薄膜厚度在线精确测量,对控制薄膜产品的精度和降低成本,有着非常重要的意义。本文通过一种基于红外线的薄膜厚度测量技术,实现对薄膜厚度实时在线的测量。本文主要研究使用红外技术实现对薄膜厚度测量的原理,并在此原理基础上设计了以DSP为核心处理器的红外薄膜厚度在线测量系统。该系统主要包括红外信号发生电路、红外信号接收电路、模拟信号处理电路、数字信号核心处理器TMS320F2812以及人机交互界面。实现红外信号驱动、光电转换、模拟信号处理、AD采样、数字信号处理、数据的实时显示和人机交互等功能。本系统基于原理,即利用透射光光强衰减程度和薄膜厚度之间满足该定理,通过最终测量透射光光强所对应的电信号实现对薄膜厚度的测量。为了尽量避免干扰,该在线测量系统加入了反馈装置。本文介绍了薄膜厚度在线测量系统的实现过程,对在线系统的软硬件部分分别进行了分析、设计和调试。本系统以处理器TMS320F2812为核心,主要由光信号驱动电路、红外接收电路、模拟信号处理电路、AD采样和处理电路、人机交互四个部分组成。本文使用AVR单片机配合LM317稳压器来产生2.0k Hz的方波,驱动红外发光管产生3.4um红外测量光;使用以Pbse红外光敏电阻为核心构成的红外接收电路获取红外透射光信号,经过光电转换转换成电信号,电信号经过前置信号处理和放大后,引入到模拟滤波芯片MAX275设计的标准带通滤波器中,最终得到信噪比较高的模拟信号;采用16位8通道AD7606对模拟信号和红外接收电路温漂信号进行信号采样,DSP核心处理器F2812使用FIR数字滤波器进行数字滤波,并将红外接收电路温漂信号作为反馈信号引入到数据计算中,利用原理,得到薄膜厚度与光强度关系;DSP核心处理器F2812和液晶显示触摸屏经过程序设计和通信设置,实现人机交互功能。本系统应用CCS软件开发平台结合MATLAB中的滤波工具,实现对系统软件部分的编程,调试以及仿真。实验结果表明,本系统能够排除干扰,在测量量程内实现精度控制在5%以内的指标要求,实现对薄膜厚度进行实时在线准确测量。
[Abstract]:In the production and processing of thin films, it is of great significance to realize the on-line accurate measurement of film thickness and to control the precision and reduce the cost of film products. In this paper, a kind of infrared film thickness measurement technology is used to measure the film thickness in real time. In this paper, the principle of infrared thin film thickness measurement using infrared technology is studied. Based on this principle, an infrared film thickness measurement system based on DSP core processor is designed. The system mainly includes infrared signal generating circuit, infrared signal receiving circuit, analog signal processing circuit, digital signal core processor TMS320F2812 and man-machine interface. The functions of infrared signal driving, photoelectric conversion, analog signal processing, AD sampling, digital signal processing, real-time display of data and man-machine interaction are realized. The system is based on the principle that the attenuation degree of transmitted light intensity and the thickness of the film satisfy the theorem, and the thickness of the film can be measured by the electrical signal corresponding to the final measurement of the intensity of the transmitted light. In order to avoid interference as far as possible, a feedback device is added to the online measurement system. This paper introduces the realization process of the film thickness online measurement system, and analyzes, designs and debugs the software and hardware parts of the online system. The system is composed of four parts: optical signal driving circuit, infrared receiving circuit, analog signal processing circuit, AD sampling and processing circuit and man-machine interaction. In this paper, AVR single-chip microcomputer and LM317 regulator are used to generate 2.0 k Hz square wave, and the infrared luminous tube is driven to generate 3.4um infrared measurement light. Infrared receiving circuit composed of Pbse infrared photosensitive resistor is used to obtain infrared transmission light signal, which is converted into electric signal by photoelectric conversion, and the signal is processed and amplified by pre-signal. The analog signal with high SNR is obtained by introducing it into the standard bandpass filter designed by analog filter chip MAX275. The 16 bit 8 channel AD7606 is used to sample the analog signal and the temperature drift signal of the infrared receiving circuit. The core processor F2812 of DSP is digitally filtered by FIR digital filter. The temperature drift signal of the infrared receiving circuit is introduced into the data calculation as the feedback signal and the relationship between the film thickness and the light intensity is obtained by using the principle. DSP core processor F2812 and LCD touch screen are programmed and set up to realize man-machine interaction. This system uses CCS software development platform and the filter tool in MATLAB to realize the programming, debugging and simulation of the software part of the system. The experimental results show that the system can eliminate interference, achieve the requirement of accuracy within 5% of the measurement range, and realize the real-time and accurate measurement of film thickness.
【学位授予单位】：哈尔滨工业大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TN219;TP274
本文编号：2423452
[Abstract]:In the production and processing of thin films, it is of great significance to realize the on-line accurate measurement of film thickness and to control the precision and reduce the cost of film products. In this paper, a kind of infrared film thickness measurement technology is used to measure the film thickness in real time. In this paper, the principle of infrared thin film thickness measurement using infrared technology is studied. Based on this principle, an infrared film thickness measurement system based on DSP core processor is designed. The system mainly includes infrared signal generating circuit, infrared signal receiving circuit, analog signal processing circuit, digital signal core processor TMS320F2812 and man-machine interface. The functions of infrared signal driving, photoelectric conversion, analog signal processing, AD sampling, digital signal processing, real-time display of data and man-machine interaction are realized. The system is based on the principle that the attenuation degree of transmitted light intensity and the thickness of the film satisfy the theorem, and the thickness of the film can be measured by the electrical signal corresponding to the final measurement of the intensity of the transmitted light. In order to avoid interference as far as possible, a feedback device is added to the online measurement system. This paper introduces the realization process of the film thickness online measurement system, and analyzes, designs and debugs the software and hardware parts of the online system. The system is composed of four parts: optical signal driving circuit, infrared receiving circuit, analog signal processing circuit, AD sampling and processing circuit and man-machine interaction. In this paper, AVR single-chip microcomputer and LM317 regulator are used to generate 2.0 k Hz square wave, and the infrared luminous tube is driven to generate 3.4um infrared measurement light. Infrared receiving circuit composed of Pbse infrared photosensitive resistor is used to obtain infrared transmission light signal, which is converted into electric signal by photoelectric conversion, and the signal is processed and amplified by pre-signal. The analog signal with high SNR is obtained by introducing it into the standard bandpass filter designed by analog filter chip MAX275. The 16 bit 8 channel AD7606 is used to sample the analog signal and the temperature drift signal of the infrared receiving circuit. The core processor F2812 of DSP is digitally filtered by FIR digital filter. The temperature drift signal of the infrared receiving circuit is introduced into the data calculation as the feedback signal and the relationship between the film thickness and the light intensity is obtained by using the principle. DSP core processor F2812 and LCD touch screen are programmed and set up to realize man-machine interaction. This system uses CCS software development platform and the filter tool in MATLAB to realize the programming, debugging and simulation of the software part of the system. The experimental results show that the system can eliminate interference, achieve the requirement of accuracy within 5% of the measurement range, and realize the real-time and accurate measurement of film thickness.
【学位授予单位】：哈尔滨工业大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TN219;TP274
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相关硕士学位论文 前1条
1 李恒;电容式塑料薄膜厚度扫描检测系统的研究[D];天津大学;2007年
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