【作者】 乔永明；

【导师】 梁鸿生；

【作者基本信息】 西安理工大学 ， 检测技术与自动化装置， 2003， 硕士

【摘要】 本文简述了电涡流传感器技术应用及理论研究的现状，揭示了在热轧钢管裂纹探伤方面国内与国外的巨大差别，并提出了两种钢管裂纹在线检测的方案。通过对涡流传感器的静态特性和动态特性的分析，指出影响传感器测量范围、灵敏度、线性度等指标的因素；推导出涡流传感器动态性能可以用两个串联的一阶惯性系统来表示，并设计出无源超前的校正电路，保证在不影响灵敏度的前提下可以大大的改善其系统的动态特性。 通过大量的实验，一方面验证了大传感器测量小缺陷的可行性；另一方面又发现了采用线圈阻抗的相位分量识别裂纹缺陷相对于其幅值分量，具有线性度好；灵敏度高；测量范围宽；抗干扰性强的优点。对于抑制“提离”的问题采用单频双参数的方法结合最小二乘法曲面拟合解耦简单而且有效。 本系统采用TI公司的TMSC548芯片作为整个检测仪的信号数字处理器，本着性价比的宗旨，激励源电路以MAX038芯片为核心，利用CCS软件仿真了基于相关法测量信号的相位差，通过比较在此基础上又提出了一种基于过零法对等效脉宽计数测量信号相位差的方法，通过对计数器预置阀值，从而实现在无裂纹出现的情况下，DSP可以对信号不作处理，大大降低了系统对DSP时间和空间资源的占有率。设计了激光发射和接受装置从而取得行同步信号。 最后结合本课题，提出了一些有效的嵌入式系统的硬件及软件抗干扰技术。更多还原

【Abstract】 The paper introduces the technology applies and theory research conditions of eddy-curent sensor, reveals the large spatial difference between our country and others about in real detection of steel pipe crackle. Though the analysis of statical and dynamic characters on eddy-current sensor, it puts forward the influence factors of detective range and sensitivity and linear. On the other hand, it also makes dynamic character factor equel to two inertia system .It not only improves dynamic character but also has little influences to sensitivity by correcting with non-power circuit.Through massive experiments, we can get that it is feasible to detect little flaw by big sensor, and it is also verified that the method which discerns the crackle by coil impedance phase has better linear, higher sensitivity, wider detective range and better anti-interference than by amplitude, it is ordinary and effective to solve problem of seting up sensor by testing two parameter with one work frequency on the basis of using two least multiplication.The system uses TMSC548 of TI co. as the whole detective CPU. The excited power circuit adopts MAX038 as a core according to capability and value. On the basis of detecting the phase difference by correlative method with CCS software, the paper puts forward a method that detects the phase difference by taking count of equivalent pulse width, and preset counter’s value so that DSP need not deal with the signal when there has not crackle. It can largely reduce the DSP possess rate of time and space. The synchronism signal is obtained by laser equipment.At last, the paper has put forward some effective means of software and hardware anti-interference about built-in system.更多还原