带有反馈机制的微孔传感信号检测系统设计

发布时间：2018-02-06 00:50

本文关键词： 微孔传感器阻塞脉冲信号 FPGA 反馈机制　出处：《天津大学》2014年硕士论文　论文类型：学位论文

【摘要】：微孔传感器是从上世纪50年代的发明专利——Coulter计数器的基础上发展而来的,能够在溶液环境中对待测物进行检测的传感器,其输出的电流形式的阻塞脉冲信号包含了待测物空间结构信息。微纳加工能力的不断提升,使得固态微孔的制备成为可能,微孔传感器的应用范围也不断拓展。如何克服待测物穿过微孔过程的随机性,提高微孔传感器的检测精度成为影响其发展的一个重要研究方向。本论文首先对阻塞脉冲信号进行了分析,尝试利用聚焦离子束(FIB)加工锥形结构来获得锥形孔,并对实验结果中产生的形貌偏差进行了深入的分析,为实现锥形孔的制备打下基础。随后根据阻塞脉冲信号的特点,设计了一套带有反馈机制的微孔传感信号检测系统。与传统的开环的检测系统相比,本论文设计的系统添加了反馈回路,实现了系统闭环,为控制待测物穿过微孔过程提供了系统基础。该系统包含了阻塞脉冲信号的放大调理电路,模数转换模块,基于FPGA的双FIR数字滤波器,搭载μC/OS-II系统的Nios II软核处理器以及微孔传感器驱动模块等部分。通过分析实际阻塞脉冲对信号处理的需求,本论文设计的系统用硬件加速器的形式在FPGA上实现了数字滤波器,既保证了系统的灵活性也满足了系统的实时性要求。同时利用双FIR滤波器,使系统得以快速捕捉阻塞脉冲信号,并能够输入信号进行有效的处理。经过多组测试,本论文设计的系统可以通过灵活地调整,实现对具有不同信噪比的阻塞脉冲信号进行快速有效地捕捉,并准确输出反馈信号。
[Abstract]:The microporous sensor is developed from the invention patent of -50s, Coulter counter, which can detect the object in the solution environment. The blocking pulse signal in the form of current contains the spatial structure information of the object to be tested. With the continuous improvement of micro-nano processing ability, it is possible to prepare solid micropores. The application of microporous sensor is also expanding. How to overcome the randomness of the process of the object passing through the micropore. Improving the detection accuracy of microporous sensor has become an important research direction to affect its development. Firstly, the blocking pulse signal is analyzed in this paper. The conical hole was fabricated by using focused ion beam beam (FIB) to obtain the conical hole, and the shape deviation from the experimental results was analyzed in depth. Then according to the characteristics of blocking pulse signal, a micro-hole sensing signal detection system with feedback mechanism is designed, which is compared with the traditional open-loop detection system. The feedback loop is added to the system in this paper, and the closed loop of the system is realized, which provides the system foundation for controlling the process of the object to be tested through the microhole. The system includes the amplification and conditioning circuit of the blocking pulse signal. Analog-to-digital conversion module, double FIR digital filter based on FPGA. The Nios II soft core processor with 渭 C / OS-II system and the driving module of the microhole sensor are used to analyze the signal processing requirements of the actual blocking pulse. The system designed in this paper realizes the digital filter on FPGA in the form of hardware accelerator, which not only ensures the flexibility of the system but also meets the real-time requirement of the system. At the same time, the double FIR filter is used. The system can quickly capture the blocking pulse signal, and can input the signal for effective processing. After a number of tests, the system designed in this paper can be flexibly adjusted. The blocking pulse signal with different signal-to-noise ratio can be captured quickly and effectively, and the feedback signal can be output accurately.
【学位授予单位】：天津大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TP212;TN911.7

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