电阻层析测量系统数据采集装置的设计
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摘要
本文根据电阻层析成像(ERT)技术的相邻测试原理,设计了ERT数据采集系统样机,并对样机进行了测试。它包括以下电路设计:设计了基于直接数字合成(DDS)技术的幅度、频率可以数字控制的激励源,通过增加反馈通道提高了传统双运放电压控制电流源(VCCS)电路的带负载能力。利用复杂可编程逻辑器件(CPLD)设计了相邻测量模式的ERT电极选通逻辑控制器,这种设计可以最小化更改硬件设计而实现其他方式的ERT测量。将滤波器置于前置放大电路的反馈通道中,这样不仅去除了电极信号的直流偏置电压,而且避免了在正向通道中直接采用交流耦合引起的相位误差。还设计了程控放大、开关解调、低通滤波等功能电路实现了对ERT微弱信号的调理。采用高速AD转换器实现了数据采集,采集数据稳定度高,最大误差为3LSB。通过USB2.0接口实现了上位机对数据采集装置的控制。编写了基于Visual Basic 6.0的数据采集软件,实现了对激励源大小和频率、程控放大器初始增益、采样速率等参数的设置。图像重建算法是COM化的线性反投影(LBP)成像算法,而且该COM模块被集成到了数据采集软件中。论文还给出了16电极ERT测试装置的实验结果,测试了不同电导率液体下的信号并确定出圆形塑料棒的位置,并对相应结果做了分析。该数据采集装置样机使用方便,可以为今后的研究工作提供数据支持。
In this thesis, a tested prototype of data acquisition of an Electrical Resistance Tomographic (ERT) measurement system is presented, according to the principle of adjacent method. It entails the following circuit designs: A measuring current source is formed by a chip of direct digital synthesis (DDS) technology whose amplitude and frequency is programmable. The loading capacity of a traditional dual-opamp structured voltage controlled current source (VCCS) is enhanced by implementing a feedback channel design. A CPLD circuit based electrode selection controller, using the principle of adjacent measurement method, is designed. Such a design permits the flexible modification of ERT measurement strategy but would minimize the hardware change should such modification is necessary. The preamplifier is implemented in such a way that a special filter is embedded in the feedback channel to remove the offset DC voltage as well as reduce the phase error introduced from the direct AC coupling in the forward channel; Other designs include a programmable gain amplifier, a switch demodulator, and a lowpass filter to condition the weak analog signal; The data acquisition circuit is formed by a high speed AD which is found stable with a maximum error of 3LSBs; The measuring device (slave unit) can be controlled by a host computer through a USB interface; A Visual Basic 6.0 based data acquisition software is designed which is able to set the frequency and amplitude of current source,the initial gain of amplifier, the data acquisition speed etc. The tomographic image reconstruction is performed by a COM module that implements the Linear Back Projection (LBP) algorithm. This COM module is integrated into the data acquisition software. The experimental results obtained from a test section that contains 16 electrodes are also described in the thesis. Measurement of signal response with regarding to liquids of different conductivities and phantom (a circular plastic rod) positions are given and analysis is performed accordingly. The prototype is very easy to use and it can supply ERT measurement data for future research work.
In this thesis, a tested prototype of data acquisition of an Electrical Resistance Tomographic (ERT) measurement system is presented, according to the principle of adjacent method. It entails the following circuit designs: A measuring current source is formed by a chip of direct digital synthesis (DDS) technology whose amplitude and frequency is programmable. The loading capacity of a traditional dual-opamp structured voltage controlled current source (VCCS) is enhanced by implementing a feedback channel design. A CPLD circuit based electrode selection controller, using the principle of adjacent measurement method, is designed. Such a design permits the flexible modification of ERT measurement strategy but would minimize the hardware change should such modification is necessary. The preamplifier is implemented in such a way that a special filter is embedded in the feedback channel to remove the offset DC voltage as well as reduce the phase error introduced from the direct AC coupling in the forward channel; Other designs include a programmable gain amplifier, a switch demodulator, and a lowpass filter to condition the weak analog signal; The data acquisition circuit is formed by a high speed AD which is found stable with a maximum error of 3LSBs; The measuring device (slave unit) can be controlled by a host computer through a USB interface; A Visual Basic 6.0 based data acquisition software is designed which is able to set the frequency and amplitude of current source,the initial gain of amplifier, the data acquisition speed etc. The tomographic image reconstruction is performed by a COM module that implements the Linear Back Projection (LBP) algorithm. This COM module is integrated into the data acquisition software. The experimental results obtained from a test section that contains 16 electrodes are also described in the thesis. Measurement of signal response with regarding to liquids of different conductivities and phantom (a circular plastic rod) positions are given and analysis is performed accordingly. The prototype is very easy to use and it can supply ERT measurement data for future research work.
引文
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[7]邓湘等.提高电阻层析成像实时性能的研究[J].天津大学报,2001,34(4):467-471.
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[11]魏颖.电阻层析成像技术(ERT)及其在两相流测量中的应用研究[J].东北大学学报,2001.
[12]魏颖,王师,赵进创,陆增喜.电阻层析成像技术的研究现状与应用发展趋势[J].东北大学信息科学与工程学院,2000,29(4):340-344.
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[15] Murai T, Kagawa Y. Electrical impedance computed tomography based on a finite element model. IEEE Trans on BME,1985,32(3):177-184.
[16]李英.电阻层析成像技术软场特性及图像重建算法研究[D].浙江大学,杭州:2003.
[17]孙永进.电阻层析成像(ERT)计算机仿真研究[D] .天津大学,天津:2002.
[18]刘小平.电阻层析成像技术在两相流参数检测中的应用研究[D].天津大学,天津:2001.
[19]张亮.基于Matlab的电阻层析成像(ERT)与仿真平台设计[D].中国石油大学(华东),东营:2007.
[20] Analog Devices.CMOS DDS Modulator AD7008 Data Sheet,1995.
[21]童长飞.C8051F系列单片机开发与C语言编程[M].北京航空航天大学出版社,2005.
[22]张伟等.电路设计与制板:Protel DXP高级应用[M].北京人民邮电出版,2004.
[23]熊伟等.Multisim 7电路设计及仿真应用[M].清华大学出版社,2005.
[24]远坂近昭.测量电子电路设计—滤波器篇[M].科学出版社,2006.
[25]丁士圻.模拟滤波器[M].哈尔滨工程大学出版社,2004.
[26]刘树棠等.基于运算放大器和模拟集成电路的电路设计[M].西安交通大学出版社,2004.
[27] Adrian A,D,and Rainer K,A Simple Microcontroller Based Digital Lock-in Amplifier for the Detection of Low Level Optical Signals[C],In:Proceedings of the First IEEE International Workshop on Electronic Design,Test and Applications(DELTA'02),Jan,29-31,2002,Christchurch,New Zealand,486-488.
[28] Wilkinson A J,Randall E W,Durrentt D et al. The Design of a 1000 Frames/Second ERT Data Capture System and Calibration Techniques Employed[C]. 3rd World Congress on Industrial Process Tomography,Banff,Canada,2003.
[29]王彬彬、董峰.电阻层析成像系统信号预处理模块的设计[J].仪器仪表用vol.13 2006 NO.6.
[30]温世仁.微弱信号检测系统中的接地与屏蔽技术分析[M].宇航计测技术,2005
[31]高晋占.微弱信号检测[M].清华大学出版社,2004.
[32]杨刚,龙海燕.现代电子技术—VHDL与数字系统设计[M].电子工业出版社,2004.
[33]齐洪喜,陆颖.VHDL电路设计实用教程[M].清华大学出版社,2004.
[34]王诚,吴继华等.Altera FPGA/CPLD设计[M].人民邮电出版社,2005.
[35]周润景,图雅等.基于QuartusII的FPGA/CPLD数字系统设计实例[M].电子工业出版社,2007.
[36] Thomas Kugelstadt.Getting the most out of your instrumentation amplifier design. Texas Instruments Incorporated,,2005.
[37] Walt Kester,James Bryant,and Mike Byrne.Grounding Data Converters and Solving the Mystery of AGND and DGND.Analog Devices Tutorials,2009.
[38]廖济林.USB2.0应用系统开发实例精讲[M].电子工业出版社,2006.
[39]严石等.基于USB2.0的数据采集系统设计[J].电子器件,2008.
[40]康华光.电子技术基础(模拟部分)第四版[M].高等教育出版社,2004.
[41]王俊忠,梁海刚,石旭斌. Matlab外部程序接口实现方法研究[J].计算机与信息技术,2005.
[42]张亮,王继阳等.Matlab与C/C++混合编程[M].北京:人民邮电出版社,2008.
[43]黄锡全.基于COM组件的VB与Matlab接口编程[J].电脑编程技巧与维护,2004.
[44]朱志松,郭晓丽,朱小松.VB与Matlab接口编程探讨[J].技术应用,2003.
[45]徐静.Matlab与VB集成[J].计算机世界,2001.
[46]张志涌.精通Matlab 6.5版[M].北京:北京航空航天大学出版社,2003.
[47]倪光正,钱秀英.电磁场数值计算[M].北京:高等教育出版社,1996.
[48]毕德显.电磁场理论[M] .北京:电子工业出版社,1985.
[49]盛建霓.电磁场数值分析[M].北京:科学出版社,1984.
[50]署恒木,仝兴华.工程有限单元法基础[M].东营:石油大学出版社,1998.
[51]谭超.电阻层析成像系统及两相流测量的研究[D].天津大学,2006.
[52]李二平.ERT数据采集系统的优化与模块化设计[D].天津大学,2006.
[2]王微微.气液两相流参数检测新方法研究[D].浙江大学,2006.
[3]李海青等.两相流参数检测及应用[M].杭州:浙江大学出版社,1991.
[4]刘圣志等.石油工业多相计量技术进展[J].石油规划设计,2006,17(1):1-4.
[5]吕宇玲等.多相流量计及其在石油工业中的应用[J] .石油规划设计,2005,16(2):47-48.
[6]魏颖.电阻层析成象技术(ERT)及其在两相流测量中的应用研究[D].东北大学,2001.
[7]邓湘等.提高电阻层析成像实时性能的研究[J].天津大学报,2001,34(4):467-471.
[8] Beck.M.S.and Williams R.A,Process tomography:an European inovation and its applications[J],Meas.Sci.&Technol,1996,215-224.
[9] Beck.M.S.,Hoyle B.S.,Morris.M.A.Waterfall R.C and Williams R.A.,Process Tomography-Implementation for Industrial Porcess[J],Ediotrs.1995.
[10]胡松钰,黄志尧.高速电阻层析成像数据采集系统设计[J].传感技术学报,2008,21(1):79-82.
[11]魏颖.电阻层析成像技术(ERT)及其在两相流测量中的应用研究[J].东北大学学报,2001.
[12]魏颖,王师,赵进创,陆增喜.电阻层析成像技术的研究现状与应用发展趋势[J].东北大学信息科学与工程学院,2000,29(4):340-344.
[13] Mi Wang etc. Electrical resistance tomography sensing systems for industrial applications[M] . in Industrial Process Tomography-II,1997.
[14]南国芳.EIT阵列电极优化设计及图像重建算法研究[D].天津大学,天津:2001.
[15] Murai T, Kagawa Y. Electrical impedance computed tomography based on a finite element model. IEEE Trans on BME,1985,32(3):177-184.
[16]李英.电阻层析成像技术软场特性及图像重建算法研究[D].浙江大学,杭州:2003.
[17]孙永进.电阻层析成像(ERT)计算机仿真研究[D] .天津大学,天津:2002.
[18]刘小平.电阻层析成像技术在两相流参数检测中的应用研究[D].天津大学,天津:2001.
[19]张亮.基于Matlab的电阻层析成像(ERT)与仿真平台设计[D].中国石油大学(华东),东营:2007.
[20] Analog Devices.CMOS DDS Modulator AD7008 Data Sheet,1995.
[21]童长飞.C8051F系列单片机开发与C语言编程[M].北京航空航天大学出版社,2005.
[22]张伟等.电路设计与制板:Protel DXP高级应用[M].北京人民邮电出版,2004.
[23]熊伟等.Multisim 7电路设计及仿真应用[M].清华大学出版社,2005.
[24]远坂近昭.测量电子电路设计—滤波器篇[M].科学出版社,2006.
[25]丁士圻.模拟滤波器[M].哈尔滨工程大学出版社,2004.
[26]刘树棠等.基于运算放大器和模拟集成电路的电路设计[M].西安交通大学出版社,2004.
[27] Adrian A,D,and Rainer K,A Simple Microcontroller Based Digital Lock-in Amplifier for the Detection of Low Level Optical Signals[C],In:Proceedings of the First IEEE International Workshop on Electronic Design,Test and Applications(DELTA'02),Jan,29-31,2002,Christchurch,New Zealand,486-488.
[28] Wilkinson A J,Randall E W,Durrentt D et al. The Design of a 1000 Frames/Second ERT Data Capture System and Calibration Techniques Employed[C]. 3rd World Congress on Industrial Process Tomography,Banff,Canada,2003.
[29]王彬彬、董峰.电阻层析成像系统信号预处理模块的设计[J].仪器仪表用vol.13 2006 NO.6.
[30]温世仁.微弱信号检测系统中的接地与屏蔽技术分析[M].宇航计测技术,2005
[31]高晋占.微弱信号检测[M].清华大学出版社,2004.
[32]杨刚,龙海燕.现代电子技术—VHDL与数字系统设计[M].电子工业出版社,2004.
[33]齐洪喜,陆颖.VHDL电路设计实用教程[M].清华大学出版社,2004.
[34]王诚,吴继华等.Altera FPGA/CPLD设计[M].人民邮电出版社,2005.
[35]周润景,图雅等.基于QuartusII的FPGA/CPLD数字系统设计实例[M].电子工业出版社,2007.
[36] Thomas Kugelstadt.Getting the most out of your instrumentation amplifier design. Texas Instruments Incorporated,,2005.
[37] Walt Kester,James Bryant,and Mike Byrne.Grounding Data Converters and Solving the Mystery of AGND and DGND.Analog Devices Tutorials,2009.
[38]廖济林.USB2.0应用系统开发实例精讲[M].电子工业出版社,2006.
[39]严石等.基于USB2.0的数据采集系统设计[J].电子器件,2008.
[40]康华光.电子技术基础(模拟部分)第四版[M].高等教育出版社,2004.
[41]王俊忠,梁海刚,石旭斌. Matlab外部程序接口实现方法研究[J].计算机与信息技术,2005.
[42]张亮,王继阳等.Matlab与C/C++混合编程[M].北京:人民邮电出版社,2008.
[43]黄锡全.基于COM组件的VB与Matlab接口编程[J].电脑编程技巧与维护,2004.
[44]朱志松,郭晓丽,朱小松.VB与Matlab接口编程探讨[J].技术应用,2003.
[45]徐静.Matlab与VB集成[J].计算机世界,2001.
[46]张志涌.精通Matlab 6.5版[M].北京:北京航空航天大学出版社,2003.
[47]倪光正,钱秀英.电磁场数值计算[M].北京:高等教育出版社,1996.
[48]毕德显.电磁场理论[M] .北京:电子工业出版社,1985.
[49]盛建霓.电磁场数值分析[M].北京:科学出版社,1984.
[50]署恒木,仝兴华.工程有限单元法基础[M].东营:石油大学出版社,1998.
[51]谭超.电阻层析成像系统及两相流测量的研究[D].天津大学,2006.
[52]李二平.ERT数据采集系统的优化与模块化设计[D].天津大学,2006.