超低频振动传感器的超声相位检测方法及FPGA实现

发布时间：2018-03-15 02:11

本文选题：超低频振动　切入点：相位检测　出处：《合肥工业大学》2016年硕士论文　论文类型：学位论文

【摘要】：超低频振动是一种常见的物理现象,矿井井架、井塔、高层建筑物、铁路公路桥梁、水坝的振动、地壳震动都属此类。这类振动具有振动频率很低,1Hz以下频率成份极丰富、振幅大、破坏力较强等特点。在工程技术领域,超低频振动的测试与研究一直受到高度重视。而本课题设计的一种超低频振动传感器可实现超低频振动测量,具有重要意义。本文设计的超低频地震检波器基于超声波相位法。整个检波器由外壳、弹簧振子结构、以及超声波探头等组成。其主要原理是将振波耦合至质量块发生谐振,通过检测质量块振动过程中的位移变化规律反推目标振动信息。质量块的位移检测则通过测算超声波收发传感器的实时相位差得出。为了解决温度变化导致超声波波长变化对超声波测量结果的影响,系统采用差动式结构。本文提出了一种基于FPGA的超声波信号与采样信号同时钟源的采样电路设想以实现整周期的信号采样。针对由于振动速度存在导致超声波接收传感器信号变形,本文使用一种基于相邻信号加减的相位算法,并通过仿真方法对算法进行了验证,仿真结果表明算法自身误差并没有对测量结果精度造成影响。最后,通过实验得出传感器频响特性。
[Abstract]:Ultra low frequency vibration is a common physical phenomenon. Mine Derrick, Derrick, high-rise building, railway bridge, dam vibration and crustal vibration are all of this kind. In the field of engineering technology, the measurement and research of ultra-low frequency vibration have been attached great importance to, and a kind of ultra-low frequency vibration sensor designed in this paper can realize the measurement of ultra-low frequency vibration. The ultralow frequency seismic geophone designed in this paper is based on the ultrasonic phase method. The whole geophone consists of a shell, a spring oscillator structure and an ultrasonic probe. In order to solve the problem of ultrasonic vibration caused by temperature change, the displacement detection of mass block is obtained by measuring the real time phase difference of ultrasonic transceiver sensor. The influence of wave length variation on the results of ultrasonic measurement, The system adopts differential structure. In this paper, a sampling circuit of ultrasonic signal and sampling signal simultaneously clock source based on FPGA is proposed to realize the signal sampling of whole period. The ultrasonic connection is caused by the existence of vibration velocity. Sensor signal distortion, In this paper, a phase algorithm based on adjacent signal addition and subtraction is used, and the algorithm is verified by simulation. The simulation results show that the error of the algorithm has no effect on the accuracy of the measurement results. The frequency response characteristics of the sensor are obtained by experiments.
【学位授予单位】：合肥工业大学
【学位级别】：硕士
【学位授予年份】：2016
【分类号】：TP212;TB559

【参考文献】