CN109212019B - A far-field eddy current and magnetostrictive guided wave hybrid sensor and its detection method - Google Patents
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Abstract
本发明提供了一种远场涡流和磁致伸缩导波混合传感器及其检测方法，该方法包括S1：利用信号发生模块产生低频信号后，通过功率放大加载到激励传感器上进行远场涡流检测，获得相应频率的感应电压；S2：获得感应电压后，能够通过已知的缺陷截面积与感应电压的关系式计算得到缺陷截面积的大小；S3：利用信号发生模块产生高频信号后，通过功率放大加载到激励传感器上进行磁致伸缩导波检测；S4：通过分析磁致伸缩导波信号，获得远处的缺陷的位置信息及缺陷的大小。本发明不增加装置的前提下，结合磁致伸缩导波检测能够检测远距离缺陷和远场涡流检测近距离的缺陷的优点，提高检测缺陷的效率，能够实现对微小缺陷的定量化分析。
The present invention provides a far-field eddy current and magnetostrictive guided wave hybrid sensor and a detection method thereof. The method includes S1: after a low-frequency signal is generated by a signal generating module, it is loaded onto an excitation sensor through power amplification to perform far-field eddy current detection; Obtain the induced voltage of the corresponding frequency; S2: After the induced voltage is obtained, the size of the defect cross-sectional area can be calculated by the relationship between the known defect cross-sectional area and the induced voltage; S3: After the high-frequency signal is generated by the signal generation module, the power Magnetostrictive guided wave detection is performed by amplifying and loading on the excitation sensor; S4: by analyzing the magnetostrictive guided wave signal, the position information and the size of the defect in the distance are obtained. On the premise of not increasing the device, the invention combines the advantages of magnetostrictive guided wave detection that can detect long-distance defects and far-field eddy current detection of short-distance defects, improves the efficiency of defect detection, and can realize quantitative analysis of small defects.
Description
技术领域technical field
本发明涉及无损检测技术领域，尤其涉及一种远场涡流和磁致伸缩导波混合传感器。The invention relates to the technical field of non-destructive testing, in particular to a far-field eddy current and magnetostrictive guided wave hybrid sensor.
背景技术Background technique
目前磁致伸缩导波在管道、斜拉索纵波无损检测应用时，为了增加导波的传播距离，多采用低频作为激励，但这会降低检测缺陷的分辨率，同时会增加导波检测盲区。为了提高导波的分辨率，一般采用提高导波激励频率的方式，但由于导波多模态效应的存在，使得检测信号较为复杂，不能够对缺陷进行定量化分析。At present, in the application of magnetostrictive guided waves in the nondestructive testing of pipelines and stay cables, in order to increase the propagation distance of the guided waves, low frequencies are often used as excitation, but this will reduce the resolution of defect detection and increase the blind area of guided wave detection. In order to improve the resolution of the guided wave, the method of increasing the excitation frequency of the guided wave is generally adopted. However, due to the existence of the multi-modal effect of the guided wave, the detection signal is complicated, and the quantitative analysis of the defect cannot be carried out.
目前技术中，为了克服磁致伸缩导波检测的缺点，结合其它检测方式进行检测。将磁致伸缩导波检测和漏磁检测进行结合，通过漏磁检测实现对斜拉索自由端进行检测，以提高检测的灵敏度和分辨率，通过磁致伸缩导波实现对固定区域进行检测，克服检测区域不能够接近的缺点。由于磁致伸缩导波会随着传播距离增加，幅值逐渐减小，这会减小导波检测分辨率，同时降低缺陷检测能力，为了提高检测能力，结合磁致伸缩导波和SQUID进行检测，实现高灵敏度缺陷检测。In the current technology, in order to overcome the shortcomings of magnetostrictive guided wave detection, the detection is performed in combination with other detection methods. The magnetostrictive guided wave detection and the magnetic flux leakage detection are combined, and the free end of the stay cable is detected by the magnetic flux leakage detection, so as to improve the detection sensitivity and resolution, and the fixed area can be detected by the magnetostrictive guided wave. Overcome the disadvantage that the detection area cannot be approached. Since the magnetostrictive guided wave increases with the propagation distance, the amplitude gradually decreases, which will reduce the detection resolution of the guided wave and reduce the defect detection ability. In order to improve the detection ability, the magnetostrictive guided wave and SQUID are combined for detection. , to achieve high-sensitivity defect detection.
发明内容SUMMARY OF THE INVENTION
为了解决现有技术中的不足，本发明在不增加检测装置的前提下，实现远场涡流和磁致伸缩导波混合传感器，实现对管道、斜拉索的内部缺陷检测。In order to solve the deficiencies in the prior art, the present invention realizes a far-field eddy current and magnetostrictive guided wave hybrid sensor without adding a detection device, and realizes the detection of internal defects of pipes and stay cables.
本发明具体通过如下技术方案实现：The present invention is specifically realized through the following technical solutions:
一种远场涡流和磁致伸缩导波混合传感器检测方法，包括以下步骤：A far-field eddy current and magnetostrictive guided wave hybrid sensor detection method, comprising the following steps:
S1：利用信号发生模块产生低频信号后，通过功率放大加载到激励传感器上进行远场涡流检测，获得相应频率的感应电压；S1: After the low-frequency signal is generated by the signal generation module, it is loaded on the excitation sensor through power amplification for far-field eddy current detection, and the induced voltage of the corresponding frequency is obtained;
S2：获得感应电压后，能够通过已知的缺陷截面积与感应电压的关系式计算得到缺陷截面积的大小；S2: After the induced voltage is obtained, the size of the defect cross-sectional area can be calculated through the known relationship between the defect cross-sectional area and the induced voltage;
S3：利用信号发生模块产生高频信号后，通过功率放大加载到激励传感器上进行磁致伸缩导波检测；S3: After the high-frequency signal is generated by the signal generation module, it is loaded onto the excitation sensor through power amplification for magnetostrictive guided wave detection;
S4：通过分析磁致伸缩导波信号，获得远处的缺陷的位置信息及缺陷的大小。S4: By analyzing the magnetostrictive guided wave signal, the position information of the distant defect and the size of the defect are obtained.
作为本发明的进一步改进，所述低频信号为频率1kHz的正弦波。As a further improvement of the present invention, the low-frequency signal is a sine wave with a frequency of 1 kHz.
作为本发明的进一步改进，所述高频信号为高频正弦波。As a further improvement of the present invention, the high-frequency signal is a high-frequency sine wave.
作为本发明的进一步改进，所述缺陷截面积与感应电压成二次关系，所述关系式通过拟合的方式得到。As a further improvement of the present invention, the defect cross-sectional area and the induced voltage have a quadratic relationship, and the relationship is obtained by fitting.
作为本发明的进一步改进，所述混合传感器包括信号发生模块、功率放大模块、激励传感器、检测传感器、信号处理模块和信号记录模块。As a further improvement of the present invention, the hybrid sensor includes a signal generating module, a power amplifying module, an excitation sensor, a detection sensor, a signal processing module and a signal recording module.
作为本发明的进一步改进，所述方法针对铁磁性管道、斜拉索进行检测。As a further improvement of the present invention, the method detects ferromagnetic pipes and stay cables.
另一方面，本发明提供了一种远场涡流和磁致伸缩导波混合传感器，用于实现本发明的检测方法，其包括信号发生模块、功率放大模块、激励传感器、检测传感器、信号处理模块和信号记录模块。In another aspect, the present invention provides a far-field eddy current and magnetostrictive guided wave hybrid sensor for implementing the detection method of the present invention, which includes a signal generation module, a power amplification module, an excitation sensor, a detection sensor, and a signal processing module and signal recording module.
作为本发明的进一步改进，所述信号发生模块与功率放大模块相连，所述功率放大模块与激励传感器相连，所述检测传感器与信号处理模块相连，所述信号处理模块与信号记录模块相连。As a further improvement of the present invention, the signal generating module is connected to a power amplifying module, the power amplifying module is connected to an excitation sensor, the detection sensor is connected to a signal processing module, and the signal processing module is connected to a signal recording module.
作为本发明的进一步改进，所述信号发生模块为信号发生电路。As a further improvement of the present invention, the signal generating module is a signal generating circuit.
本发明的有益效果是：1)利用远场涡流检测和磁致伸缩导波检测相结合的方式，能够不增加其他传感器装置；2)在不移动传感器的前提下，结合磁致伸缩导波检测能够检测远距离缺陷和远场涡流检测近距离的缺陷的优点，提高检测缺陷的效率；3)结合远场涡流检测，能够提高检测缺陷的灵敏度，能够实现对微小缺陷的定量化分析；4)结合磁致伸缩导波和远场涡流检测，能够提高数据挖掘能力，增加检测缺陷的类型。The beneficial effects of the present invention are: 1) by combining far-field eddy current detection and magnetostrictive guided wave detection, other sensor devices can be added; 2) on the premise of not moving the sensor, combined with magnetostrictive guided wave detection The advantages of being able to detect long-distance defects and far-field eddy current detection of short-distance defects, improve the efficiency of detection of defects; 3) Combined with far-field eddy current detection, it can improve the sensitivity of detection of defects, and can realize quantitative analysis of small defects; 4) The combination of magnetostrictive guided waves and far-field eddy current testing can improve data mining capabilities and increase the types of detected defects.
附图说明Description of drawings
图1是磁致伸缩传感器的原理图；Figure 1 is a schematic diagram of a magnetostrictive sensor;
图2是本发明的混合传感器的结构框图；Fig. 2 is the structural block diagram of the hybrid sensor of the present invention;
图3是本发明的混合传感器的仿真示意图；Fig. 3 is the simulation schematic diagram of the hybrid sensor of the present invention;
图4是当缺陷截面积一定时，缺陷在不同位置的感应电压曲线；Figure 4 is the induced voltage curve of the defect at different positions when the cross-sectional area of the defect is constant;
图5是当缺陷位置和截面积一定时，不同长度缺陷的感应电压曲线；Figure 5 shows the induced voltage curves of defects with different lengths when the defect position and cross-sectional area are constant;
图6是当缺陷长度和位置一定时，不同截面积感应电压曲线。Figure 6 shows the induced voltage curves of different cross-sectional areas when the defect length and position are constant.
具体实施方式Detailed ways
下面结合附图说明及具体实施方式对本发明进一步说明。The present invention will be further described below with reference to the accompanying drawings and specific embodiments.
本发明通过原有的磁致伸缩传感器施加低频交流激励，结合磁致伸缩导波和远场涡流的优点进行管道的缺陷检测，原理如图1所示。The invention applies low-frequency AC excitation through the original magnetostrictive sensor, and combines the advantages of magnetostrictive guided waves and far-field eddy currents to detect pipeline defects. The principle is shown in FIG. 1 .
本发明的混合传感器主要由信号发生模块、功率放大模块、激励传感器、检测传感器、信号处理模块和信号记录模块组成，如图2所示。The hybrid sensor of the present invention is mainly composed of a signal generation module, a power amplification module, an excitation sensor, a detection sensor, a signal processing module and a signal recording module, as shown in FIG. 2 .
通过磁致伸缩传感器检测管道远处缺陷，但是磁致伸缩导波存在检测盲区，其检测微小缺陷能力较差，所以本发明结合远场涡流技术实现磁致伸缩导波盲区的检测，通过对远场涡流的感应电压进行分析，以检测盲区内部的缺陷，尤其是管道的内部缺陷。The magnetostrictive sensor is used to detect the defects in the far distance of the pipeline, but the magnetostrictive guided wave has a detection blind area, and its ability to detect small defects is poor. Therefore, the invention combines the far-field eddy current technology to detect the blind area of the magnetostrictive guided wave. The induced voltage of the field eddy current is analyzed to detect the defects inside the dead zone, especially the internal defects of the pipeline.
为了验证远场涡流检测管道内部缺陷的准确性，本发明对线圈施加低频励磁，记录在一定距离处的检测线圈感应电压，通过感应电压的变化，对缺陷进行定量化分析。在实际实验中，由于缺陷样本数较少，所以采用仿真分析的方式首先对远场涡流检测内部缺陷进行验证，仿真示意图如图3所示。In order to verify the accuracy of the far-field eddy current detection of the internal defects of the pipeline, the invention applies low-frequency excitation to the coil, records the induced voltage of the detection coil at a certain distance, and quantitatively analyzes the defects through the change of the induced voltage. In the actual experiment, due to the small number of defect samples, the method of simulation analysis is used to first verify the internal defects of the far-field eddy current detection. The simulation diagram is shown in Figure 3.
针对缺陷不同位置，不同截面积以及不同长度进行仿真发现，当缺陷截面积一定时，缺陷在不同位置的感应电压如图4所示，由图4可知，当缺陷截面积一定时，不同位置的缺陷感应电压变化较小。According to different positions of the defect, different cross-sectional areas and different lengths of the simulation, it is found that when the cross-sectional area of the defect is constant, the induced voltage of the defect at different positions is shown in Figure 4. It can be seen from Figure 4 that when the cross-sectional area of the defect is constant, the Defect-induced voltage changes are small.
当缺陷位置和截面积一定时，不同长度缺陷的感应电压见图5。由图5可知，缺陷长度对感应电压的影响也较小。When the defect position and cross-sectional area are constant, the induced voltages of defects with different lengths are shown in Figure 5. It can be seen from Fig. 5 that the influence of the defect length on the induced voltage is also small.
当缺陷长度和位置一定时，不同截面积感应电压见图6。由图6可知，随着缺陷截面积的增加，感应电压逐渐减小，通过对缺陷截面积和感应电压进行曲线拟合能够得到缺陷截面积和感应电压的公式，通过公式在已知感应电压后，能够计算得到缺陷截面积的大小。When the defect length and position are fixed, the induced voltages in different cross-sectional areas are shown in Figure 6. It can be seen from Figure 6 that with the increase of the defect cross-sectional area, the induced voltage gradually decreases. The formula for the defect cross-sectional area and the induced voltage can be obtained by curve fitting the defect cross-sectional area and the induced voltage. , the size of the defect cross-sectional area can be calculated.
为了验证仿真的正确性，利用远场涡流对管道缺陷进行检测。激励频率为1kHz的正弦波，将其加载到激励线圈上，在记录检测线圈的感应电压，由于实际管道内部缺陷制作较难，所以采用外部缺陷进行验证。不同缺陷的感应电压见图6。由图6可知，随着缺陷截面积的增加，其感应电压逐渐减小，但其与仿真中有一定的差异，可能是由于实际检测中的噪声及耦合状态不理想导致的。但感应电压和缺陷截面积同样成二次关系，能够通过拟合的方式得到二者关系，以便后续能够在已知感应电压时，计算得到缺陷截面积。In order to verify the correctness of the simulation, far-field eddy currents are used to detect pipeline defects. A sine wave with an excitation frequency of 1 kHz is loaded on the excitation coil, and the induced voltage of the detection coil is recorded. Since it is difficult to manufacture the actual internal defects of the pipeline, the external defects are used for verification. The induced voltages of different defects are shown in Figure 6. It can be seen from Fig. 6 that with the increase of the cross-sectional area of the defect, the induced voltage gradually decreases, but there is a certain difference between it and the simulation, which may be caused by the noise and the unsatisfactory coupling state in the actual detection. However, the induced voltage and the defect cross-sectional area also have a quadratic relationship, and the relationship between the two can be obtained by fitting, so that the defect cross-sectional area can be calculated later when the induced voltage is known.
本发明的远场涡流和磁致伸缩导波混合传感器检测实现过程如下：The detection realization process of the far-field eddy current and magnetostrictive guided wave hybrid sensor of the present invention is as follows:
S1：利用信号发生模块产生低频正弦信号后，通过功率放大加载到激励传感器上进行远场涡流检测，获得相应频率的感应电压；S1: After the low-frequency sinusoidal signal is generated by the signal generation module, it is loaded on the excitation sensor through power amplification for far-field eddy current detection, and the induced voltage of the corresponding frequency is obtained;
S2：获得感应电压后，能够通过已知的缺陷截面积与感应电压的关系式计算得到缺陷截面积的大小；S2: After the induced voltage is obtained, the size of the defect cross-sectional area can be calculated through the known relationship between the defect cross-sectional area and the induced voltage;
S3：利用信号发生模块产生高频正弦信号后，通过功率放大加载到激励传感器上进行磁致伸缩导波检测；S3: After the high-frequency sinusoidal signal is generated by the signal generation module, it is loaded on the excitation sensor through power amplification for magnetostrictive guided wave detection;
S4：通过分析磁致伸缩导波信号，获得远处的缺陷的位置信息及缺陷的大小。S4: By analyzing the magnetostrictive guided wave signal, the position information of the distant defect and the size of the defect are obtained.
综上所述，本发明通过以上几点有效提高管道检测效率。To sum up, the present invention effectively improves the pipeline detection efficiency through the above points.
以上所述仅为本发明的优选实施例，并非因此限制本发明的专利范围，凡是利用本发明说明书及附图内容所作的等效结构或等效流程变换，或直接或间接运用在其他相关的技术领域，均同理包括在本发明的专利保护范围内。The above descriptions are only preferred embodiments of the present invention, and are not intended to limit the scope of the present invention. Any equivalent structure or equivalent process transformation made by using the contents of the description and drawings of the present invention, or directly or indirectly applied to other related All technical fields are similarly included in the scope of patent protection of the present invention.
对于本领域的普通技术人员来说，在不脱离本发明构思的前提下，还可以做出若干简单推演或替换，都应当视为属于本发明的保护范围。For those of ordinary skill in the art, without departing from the concept of the present invention, some simple deductions or substitutions can be made, which should be regarded as belonging to the protection scope of the present invention.
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