涡流检测电路的设计【毕业论文】.doc

本 科 毕 业 设 计 涡流检测电路的设计 摘要 电涡流传感器是工业生产和科学研究中使用广泛的一种无损、非接触检测仪器。对被测材料敏感一直是制约电涡流传感器更广泛应用的重要因素。为了消除被测材料电磁特性对传感器输出特性的影响、提高传感器性能，需要设计出一种与材料无关的传感器测量电路。 本文为电涡流传感器设计了新型的测量电路，并对该测量电路进行了仿真、优化。具体内容如下：1.电涡流传感器与被测材料的相关性研究 目前，电涡流传感器都是通过控制探头线圈的等效阻抗来获得输出电压和检测距离之间的关系。本论文尝试采用对探头线圈的阻抗实部和虚部进行控制的方法，来研究在新的理论下电涡流传感器与被测材料的相关性。2.电涡流传感器新型电路的仿真与优化 对所设计好的新型电路各模块，通过Multisim仿真软件，检查各模块电路所实现的功能。并在此基础上，对部分电路中的结构和参数进行了优化。最终达到了较为理想的效果。3.仿真分析 通过仿真论证了在不同检测距离、不同被测材料下，探头线圈阻抗的实部和虚部之间呈线性关系，且各条直线相互平行，但各条直线之间的距离变化不满足线性关系。若能改善各直线之间距离变化的线性性，就可开发出一种与被测材料无关的电涡流传感器。 关键词：电涡流，传感器，Multisim仿真 ABSTRACT Eddy Current Sensor(ECS) is an nondestructive testing component，which is applied extensively in engineering and science researches. However, the testing performances are sensitive to the material properties,which hampers eddy current sensor applied more conveniently and extensively. In order to eliminate the influence of the electromagnetic properties of measured targets on the output of sensor and improve the performance of sensor, the new eddy current measuring.circuit is needed. In this thesis, the new ECS measure circuit is designed, simulated and optimized.The research work conducted is outlined as following.1. Study on the relativity of tested material and ECS At present, ECS obtains the relationship of the output voltage and the testing distance by controlling the equivalent impedance.In the thesis, the relativity of tested material and ECS is studied by controlling the real part and the image part of the impedance of the coil.2. Simulation and optimizing of the designed circuit The functions of each module from the designed circuit are checked by the software named Multisim.Based on the results from the simulation, structures and parameters of some modules are optimized to be better.3. The simulation analysis Under the same testing distance and different tested material,the relationship of the real part and image part of coil impedance is linear,which is demonstrated by simulation,under the different testin