导波雷达物位计回波信号采集与处理方法研究

发布时间：2019-06-26 17:15

【摘要】：现代工业实行信息化管理，物位的精确测量在工业生产中非常重要，而工业生产环境越来越复杂，对物位计的性能要求越来越高。导波雷达物位计的信号传输集中在导波杆中，能量损耗非常小，物位测量不会受到容器内其他固定结构、介质波动、泡沫、雾气、温度和压力变化等因素的影响，可以测量相对介电常数较小的介质，而且测量精度高，性能稳定，系统安装和调试简单，在物位测量领域的地位越来越重要。本文详细分析了基于传输线理论的时域反射原理和导波雷达物位计物位测量的基本原理，给出了发射信号电路参数设计，并简要介绍了系统总体方案和各模块工作过程。通过对比多种信号采样方法，并依据回波信号具有极窄脉宽的特点选择步进等效时间取样方法实现信号采样，设计了具体的回波信号接收和处理电路，重点分析了四管平衡高速取样门电路和脉冲步进延时电路原理，给出了具有详细参数的回波信号接收电路，并对本文设计的硬件电路进行电路仿真和电路板的实际测试，根据仿真波形，对电路重要参数进行了详细的分析和总结，，并对实际电路测试结果进行了分析验证。通过分析回波信号采样和处理电路仿真波形和电路板测试结果表明，本文设计的导波雷达物位计回波信号采集和接收电路能有效展宽脉宽极窄的回波信号，并实现回波信号的正确捕获，达到了基本的功能要求。
[Abstract]:Modern industry implements information management, the accurate measurement of material level is very important in industrial production, and the industrial production environment is becoming more and more complex, and the performance requirements of material level meter are getting higher and higher. The signal transmission of guided wave radar level meter is concentrated in the guide rod, the energy loss is very small, the material level measurement will not be affected by other fixed structures in the container, medium fluctuation, foam, fog, temperature and pressure change and so on. It can measure the medium with relatively small dielectric constant, and the measurement accuracy is high, the performance is stable, the system installation and debugging is simple, and the position in the field of object level measurement is becoming more and more important. In this paper, the principle of time domain reflection based on transmission line theory and the basic principle of object level measurement of guided wave radar are analyzed in detail, the design of transmitting signal circuit parameters is given, and the overall scheme of the system and the working process of each module are briefly introduced. By comparing various signal sampling methods and selecting step equivalent time sampling method to realize signal sampling according to the characteristics of echo signal with very narrow pulse width, a concrete echo signal receiving and processing circuit is designed, and the principles of four-transistor balanced high-speed sampling gate circuit and pulse stepping delay circuit are analyzed, and the echo signal receiving circuit with detailed parameters is given. The hardware circuit designed in this paper is simulated and the circuit board is tested. According to the simulation waveform, the important parameters of the circuit are analyzed and summarized in detail, and the actual circuit test results are analyzed and verified. By analyzing the simulation waveform of echo signal sampling and processing circuit and the test results of circuit board, it is shown that the echo signal acquisition and receiving circuit designed in this paper can effectively broaden the echo signal with very narrow pulse width, and realize the correct acquisition of echo signal, which meets the basic functional requirements.
【学位授予单位】：华中科技大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TN957.51

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