Fully-digital high-precision three-dimensional flux leakage signal acquisition device

Abstract

The invention discloses a fully-digital high-precision three-dimensional flux leakage signal acquisition device, which comprises more than three three-axis magnetic field sensors, wherein the signal output of the three-axis magnetic field sensors is connected with the input of an FPGA (field programmable gate array); the output of the FPGA is connected with the input of a master control chip; the output of the master control chip is connected with a USB (universal serial bus) interface which is used for transmitting data through an external cable. According to the device, the number of the three-axis magnetic field sensors can be regulated according to the size of a detected object, so that different detection precision requirements are well met; the FPGA has rich IO (input / output) interfaces, and has a relay function of data compilation and transmission, and the parallel access requirement of a plurality of paths of data can be met; a USB mode is adopted for the data transmission of the master control chip, so that high transmission speed and low interference rate are ensured; the device has the advantages of high spatial precision and synchronous acquisition of a plurality of paths, and is high in anti-interference capability and detection precision, simple in structure and easy to use.

Description

technical field [0001] The invention relates to the technical field of signal acquisition devices, in particular to an all-digital high-precision three-dimensional magnetic flux leakage signal acquisition device. Background technique [0002] As a common ferromagnetic material: steel is widely used in the national economy, but many steel products are subjected to corrosion and loads from the external environment during use, and the material may have defects, resulting in changes in the structure and shape of the material. It is the most widely used non-destructive testing technology to detect defects by magnetic flux leakage testing on ferromagnetic material products. The current magnetic flux leakage detection equipment mainly adopts one-dimensional magnetic flux leakage detection, but in order to accurately determine the size of the defect, it is often necessary to detect the three-dimensional magnetic field leakage of the defect. [0003] In the published document "Devel...

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Problems solved by technology

The patent application with the application number 201010266215.X "Low Power Consumption Intelligent 3D Magnetic Flux Leakage Detection Probe" and the patent application with the application number 201110051160.5 "Fully Digitalized 3D Flux Leakage Signal Acquisition System for Metal Pipeline Corrosion Defects" also use three one Three-dimensional magnetic flux leakage sensors are used to measure three magnetic field components in perpendicular directions to achieve the purpose of three-dimensional magnetic flux leakage detection. However, the three-dimensional detection methods mentioned in the two documents and two patent applications have inherent defects, namely It is impossible to coincide the measuring points of multiple magnetic sensors at one point. Limited by the size of the sensor itself, the distance between the detection centers of the two sensors is at least 3-4mm. Therefore, when measuring the three-dimensional leakage magnetic field at a certain point in space, it is practical What is measured is the magnetic field leakage data at three different points in the space, and there is a large position error; at the same time, the three-dimensional magnetic flux leakage detection proposed in the above documents and patent applications adopts a multiplexing method, and each group The sensors are time-divisionally gated, which results in time differences when different groups of sensors measure the magnetic field

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