Portable magnetic field imaging device

Abstract

The utility model discloses a portable magnetic field imaging device, which comprises an array type magnetic field sensor, a sensor zooming mechanism, a multi-path differential output voltage signal processing circuit, a display screen, a magnetic field imaging model and the like. The array type magnetic field sensor can obtain magnetic field information of multiple points in a plane to be measured at the same time, magnetic field measurement in multiple planes is carried out through the sensor zooming mechanism, the magnetic field imaging model enables the magnetic field information to correspond to coordinates of a spatial position to be measured, and a magnetic field vector distribution diagram is drawn. The portable magnetic field imaging device disclosed by the utility model can collect magnetic field information of a plurality of measured points in a space to be measured at a high speed, and is small in size and better in portability.

Description

TECHNICAL FIELD

[0001] The utility model relates to a kind of portable magnetic field imaging device, belong to magnetic field measurement and imaging technical field. BACKGROUND

[0002] Aiming at the complex environment such as high temperature, high pressure and high speed under which aircraft, ship and spacecraft work, cracks, indentation, tear, dent, burn and corrosion defects of ferromagnetic material in its key components are prone to occur, and magnetic field imaging device is usually used for detection.

[0003] The existing magnetic field imaging device adopts the method that three-dimensional mechanical motion platform drives magnetic sensitive probe to carry out three-dimensional scanning to obtain magnetic field data, and finally data is transmitted to computer to draw image using Matlab software, and this kind of method can only realize single sensor probe detection, and measurement point is sparse, instrument is single in magnetic sensitive direction of sensor, and measurement point is sparse, so that too many mechanical structures are needed to realize spatial multipoint measurement, leading to inconvenience, complicated operation, slow measurement speed and high price.

[0004] Due to the above reasons, it is necessary to conduct in-depth research on the existing magnetic field imaging device to solve the above problems and realize the miniaturization of the magnetic field imaging device. UTILITY MODEL CONTENT

[0005] In order to overcome the above problems, in-depth research is conducted, and a kind of portable magnetic field imaging device is designed, which comprises array type magnetic field sensor, sensor zoom mechanism, multi-channel differential output voltage signal processing circuit and display screen, the sensor zoom mechanism is used to adjust the relative position between array type magnetic field sensor and the object to be measured, and the multi-channel differential output voltage signal processing circuit is used to convert the analog signal detected by array type magnetic field sensor into magnetic field digital information.

[0006] In a preferred embodiment, the magnetic field sensor comprises a plurality of arrayed magnetic sensitive elements or devices, which can simultaneously obtain multi-point magnetic field information in the measured plane.

[0007] In a preferred embodiment, the sensor zoom mechanism is a free telescopic mechanism. When zooming, the array type magnetic field sensor is driven by the sensor zoom mechanism to move step by step in the specified direction, which changes the relative position between the array type magnetic field sensor and the measured material, so as to quickly obtain the magnetic field information of multiple measured points in the measured space.

[0008] In a preferred embodiment, the array type magnetic field sensor and the sensor zoom mechanism are detachably connected.

[0009] In a preferred embodiment, the multi-channel differential output voltage signal processing circuit comprises a signal encoder (for example, 74HC161 and LM324), a multi-channel gating switch (for example, CD4067), an instrument amplifier (for example, AD620), an A / D conversion circuit, and a single-chip microcomputer (for example, STM32F103), the analog signals output by different magnetic sensitive elements or devices are encoded by the signal encoder,

[0010] The analog signals output by different magnetic sensitive elements or devices in the magnetic field sensor are obtained in sequence through the multi-channel gating switch,

[0011] The instrument amplifier is used for voltage amplification of the encoded signals, and the A / D conversion circuit is used for converting the amplified encoded signals into digital signals,

[0012] The single-chip microcomputer is used for controlling the signal processing circuit and performing magnetic field imaging for the display screen to display the imaging results.

[0013] In a preferred embodiment, the single-chip microcomputer extracts digital level values from the magnetic field information matrix, converts them into magnetic field information, assigns corresponding RGB color values, fills the corresponding colors into the grid at the corresponding positions of the display screen, and finally displays the measured magnetic field information in the form of an image on the display screen.

[0014] The portable magnetic field imaging device has the following beneficial effects:

[0015] (1) For the problem of high-speed measurement of multiple-point magnetic fields in a to-be-measured space, the array type magnetic field sensor is used to simultaneously acquire multiple-point magnetic field information in a to-be-measured plane, and multi-plane measurement is performed through the sensor zoom mechanism, so that the magnetic field information of multiple measured points in the to-be-measured space can be collected at high speed, and the imaging device has a small volume and good portability.

[0016] (2) For the problem of multi-channel output voltage signal conditioning of the array type magnetic field sensor, the signal encoder, the multi-channel gating switch, the instrument amplifier, the A / D conversion circuit, and the single-chip microcomputer are combined, which simplifies the circuit structure and efficiently completes the digitization of the signals.

[0017] (3) The portable magnetic field imaging device of the present application constructs a magnetic field imaging model to correspond the magnetic field information to the position coordinates of the to-be-measured space and convert the digital signals into magnetic field information, and finally displays the magnetic field information in the to-be-measured space in a visual form. BRIEF DESCRIPTION OF DRAWINGS

[0018] Figure 1 The figure shows the overall structure of the portable magnetic field imaging device according to a preferred embodiment of the present application.

[0019] Symbol explanation:

[0020] 1-array magnetic field sensor;

[0021] 2-sensor zoom mechanism;

[0022] 3-multi-channel differential output voltage signal processing circuit;

[0023] 4-display screen;

[0024] 5-housing. DETAILED DESCRIPTION

[0025] The utility model will be further explained in detail below through the drawings and embodiments. Through these explanations, the characteristics and advantages of the utility model will become more clear and explicit.

[0026] The special word "exemplary" here means "as an example, embodiment or illustration". Any embodiment explained as "exemplary" here does not necessarily explain that it is superior or better than other embodiments. Although various aspects of the embodiments are shown in the drawings, the drawings are not necessarily drawn to scale unless specifically indicated.

[0027] The utility model provides a kind of portable magnetic field imaging device, as Figure 1 As shown in the figure, including array magnetic field sensor 1, sensor zoom mechanism 2, multi-channel differential output voltage signal processing circuit 3 and display screen 4 etc.

[0028] The array magnetic field sensor 1 includes a plurality of array arranged magnetic sensitive elements or devices.

[0029] The array arrangement refers to m×m or m×n magnetic sensitive element or device row arrangement, preferably m×m magnetic sensitive element or device.

[0030] The magnetic sensitive element or device refers to sensitive element or device whose characteristic parameter changes obviously with the change of external magnetic quantity, and typical magnetic sensitive element or device includes magnetic sensitive diode, magnetic sensitive triode and hall sensor.

[0031] Traditional magnetic field imaging device generally only uses single magnetic sensitive element or device to measure, and measurement point is sparse, and instrument needs excessive mechanical structure to realize spatial multi-position movement measurement due to single magnetic sensitive direction of sensor and sparse measurement point, so as to cause inconvenience, complicated operation and slow measurement speed.

[0032] In the utility model, the array magnetic field sensor simultaneously acquires multiple point magnetic field information in the measured plane, can collect the magnetic field information of multiple measured points in the measured plane at high speed, simultaneously reduces spatial displacement mechanical structure, and further realizes the reduction of device volume.

[0033] The sensor zoom mechanism is used for adjusting the relative position between the array type magnetic field sensor and the object to be measured, so that the array type magnetic field sensor can perform magnetic field measurement in multiple planes to obtain the magnetic field information of multiple measured points in the space to be measured.

[0034] Preferably, the sensor zoom mechanism is a single degree of freedom telescopic mechanism, and more preferably, the sensor zoom mechanism can be telescoped perpendicularly to the plane where the array type magnetic field sensor is located.

[0035] Preferably, the number of magnetic sensitive elements or devices in the magnetic field sensor is m x m, and the magnetic field information of multiple measured points in the space to be measured can be collected at a high speed through the sensor zoom mechanism to perform magnetic field measurement in the space to be measured.

[0036] Preferably, the sensor zoom mechanism is a step lead screw, and when zooming, the array type magnetic field sensor is driven to move in a specified direction through rotation of a step motor, and this movement changes the relative position between the array type magnetic field sensor and the material to be measured, so that the spatial magnetic field data of the surface or near surface of the object to be measured can be quickly obtained.

[0037] The multi-channel differential output voltage signal processing circuit is used for converting the analog signal detected by the array type magnetic field sensor into digital magnetic field information.

[0038] According to the utility model, the output signal of the array type magnetic field sensor is a differential voltage signal, and the number of output channels is m x m x n x 3.

[0039] Preferably, the signal processing circuit comprises a signal encoder, a multi-channel gating switch, an instrument amplifier, an A / D conversion circuit and a single-chip microcomputer, etc.

[0040] The signal encoder is used for encoding the analog signals output by different magnetic sensitive elements or devices,

[0041] The multi-channel gating switch is used for sequentially obtaining the analog signals output by different magnetic sensitive elements or devices in the array type magnetic field sensor,

[0042] The instrument amplifier is used for voltage amplifying the encoded signals, and the A / D conversion circuit is used for converting the amplified encoded signals into digital signals.

[0043] The single-chip microcomputer is used for controlling the signal processing circuit and performing magnetic field imaging, when a signal of starting collecting magnetic field information is received, a clear signal is first sent to the CLR port, and then a pulse square wave is sent to the counter, one magnetic field sensor is gated for each time of sending the square wave, the digital quantity sent by the A / D conversion circuit is read out and stored in the magnetic field information matrix corresponding to the plane coordinate to be measured, and the array information collection is ended or the counter is cleared and the magnetic field information collection is performed again to form a closed loop system by judging the level state of RCO after the 16th pulse is sent, so that the magnetic field information corresponds to the spatial position coordinate.

[0044] Preferably, the signal encoder adopts 74HC161 and LM324, the multiplexing switch adopts CD4067, the instrument amplifier adopts AD620, and the single-chip microcomputer adopts STM32F103.

[0045] The display screen is used for displaying the detection result.

[0046] Preferably, the magnetic field information is displayed in the form of a graph.

[0047] More preferably, the magnetic field information is converted into color information and displayed in the form of an image.

[0048] Specifically, the single-chip microcomputer extracts the digital level value from the magnetic field information matrix, converts it into magnetic field information, allocates the corresponding RGB color value, fills the corresponding color into the grid at the corresponding position of the display screen, and finally displays the measured magnetic field information in the form of an image on the display screen.

[0049] In a preferred embodiment, the array type magnetic field sensor is detachably connected with the sensor zoom mechanism, so as to facilitate the linearity calibration of the array type magnetic field sensor.

[0050] In a preferred embodiment, the portable magnetic field imaging device further has a battery, so that the device is more portable.

[0051] According to the utility model, the portable magnetic field imaging device has a shell 5 for fixing the array type magnetic field sensor, the sensor zoom mechanism, the multi-channel differential output voltage signal processing circuit and the display screen.

[0052] The imaging method of the portable magnetic field imaging device comprises the following steps:

[0053] S1, zero adjustment is performed on the array type magnetic field sensor;

[0054] S2, linearity calibration is performed on the array type magnetic field sensor;

[0055] S3, measuring the object, obtaining magnetic field information, and displaying on the display screen.

[0056] In S1, each magnetic sensitive element or device in the array type magnetic field sensor is adjusted one by one, when the AD value of the magnetic sensitive element or device is in the range of 2048±10, no adjustment is needed, when the detected AD value is greater than or less than the range, the corresponding position is marked, so as to set the correction deviation value to correct the magnetic sensitive element or device.

[0057] In S2, the array type magnetic field sensor is taken out of the shell and placed in a magnetic field generator (for example, CH-100), the magnetic field generator generates a calibrated magnetic field, and the detection results of each magnetic sensitive element or device are obtained under the same calibrated magnetic induction intensity, and the linearity of each magnetic sensitive element or device is calibrated according to the detection results, so that the magnetic sensitive element or device meets the linearity standard.

[0058] In S3, the relative position of the array type magnetic field sensor and the object to be measured is changed through the sensor zoom mechanism, multi-plane internal magnetic field measurement is performed, and the magnetic field information of multiple measured points in the measured space is obtained.

[0059] In each measurement process, when a signal for starting to collect magnetic field information is received, a clear signal is first sent to the CLR port of the single-chip microcomputer, and then a pulse square wave is sent to the counter of the single-chip microcomputer, one magnetic field sensor is gated for each time of sending the square wave, the digital quantity sent by the A / D conversion circuit is read out and stored in the magnetic field information matrix corresponding to the coordinate of the measured plane, and the level state of RCO after the 16th pulse is sent is judged to execute the end of this array collection information or to clear the counter and re-collect the magnetic field information, so as to form a closed loop system, and realize the correspondence between the magnetic field information and the spatial position coordinate.

[0060] Further, the digital level value is extracted from the magnetic field information matrix by the single-chip microcomputer, converted into magnetic field information, and the corresponding RGB color value is distributed, the corresponding color is filled into the grid corresponding to the position of the display screen, and finally the measured magnetic field information is displayed on the display screen in the form of an image.

[0061] In the description of the utility model, it needs to be explained that the terms "upper", "lower", "inner", "outer", "front", "rear" and the like indicate the orientation or positional relationship based on the working state of the utility model, and are only for the convenience of describing the utility model and simplifying the description, and do not indicate or imply that the indicated device or element must have a particular orientation, structure and operation, therefore, it cannot be understood as a limitation on the utility model. In addition, the terms "first", "second", "third" and "fourth" are only for the purpose of description, and cannot be understood as indicating or implying relative importance.

[0062] In the description of the utility model, it is to explain that, unless there is explicit stipulation and limitation, the term "installation" "connection" "connect" should be broad sense understanding, for example, can be fixed connection, also can be detachable connection, or integral connection ordinary, can be mechanical connection, also can be electrical connection, can be direct connection, also can pass through intermediate medium indirectly connects, can be two element inside's intercommunication, for the ordinary skilled in the art, can understand the specific meaning of the above-mentioned term in the utility model according to specific circumstances.

[0063] The utility model is described above in combination with preferred embodiments, but these embodiments are only exemplary and serve only to illustrate purposes. On this basis, various substitutions and improvements can be made to the utility model, which all fall within the protection scope of the utility model.

Claims

1. A portable magnetic field imaging device, characterized by, The arrayed magnetic field sensor, the sensor zoom mechanism, the multi-channel differential output voltage signal processing circuit and the display screen are connected in a detachable manner. The sensor zoom mechanism is used to adjust the relative position between the arrayed magnetic field sensor and the object to be measured. The arrayed magnetic field sensor is composed of m x m arrayed magnetic sensitive elements or devices. The multi-channel differential output voltage signal processing circuit is used to convert the analog signals detected by the arrayed magnetic field sensor into digital magnetic field information.

2. The portable magnetic field imaging device of claim 1, wherein, The arrayed magnetic field sensor, the sensor zoom mechanism, the multi-channel differential output voltage signal processing circuit and the display screen are connected in a detachable manner.

3. The portable magnetic field imaging device of claim 1, wherein, The sensor zoom mechanism is a free extension mechanism, and the arrayed magnetic field sensor can measure the magnetic field in n planes to be measured and collect the magnetic field information of multiple measured points in the space to be measured through the sensor zoom mechanism.

4. The portable magnetic field imaging device of claim 1, wherein, The multi-channel differential output voltage signal processing circuit comprises a signal encoder, a multi-channel gating switch, an instrument amplifier, an A / D conversion circuit and a single-chip microcomputer. The signal encoder is used to encode the analog signals output by different magnetic sensitive elements or devices, The multi-channel gating switch is used to sequentially obtain the analog signals output by different magnetic sensitive elements or devices in the arrayed magnetic field sensor, The instrument amplifier is used to amplify the voltage of the encoded signals, and the A / D conversion circuit is used to convert the amplified encoded signals into digital signals, 5. The portable magnetic field imaging device of claim 4, wherein, The single-chip microcomputer is used to control the signal processing circuit and perform magnetic field imaging for the display screen to display the imaging results. The single-chip microcomputer performs coordinate mapping and converts the digital signals into magnetic field information, converts the magnetic field information into color information, and finally displays the information in the form of images through the display screen.

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