Universal detachable sensor-based rapid electrical capacitance tomography device and imaging method

Abstract

The application discloses a kind of general detachable sensor's quick electrical capacitance tomography device and imaging method, its rigid support is the combination of two support main bodies detachable;Assembled support can be around the outside of the area needing imaging;Rigid support is set for through the multiple through holes of scale rod;Through hole is all with the center of rigid support as center and extends outward;Scale rod is hollow insulating round rod of length scale being set on surface, and its end head in the inside of rigid support is connected electrode by rotatable connecting device;Electrode is flexible electrode sheet;Shielding signal line of electrode sheet is connected to the capacitance data acquisition instrument circuit of outer end by connecting device, rod cavity of scale rod in turn;When imaging, electrode outer surface is adhered to the surface of the area needing imaging to form the outline of imaging area.The application can realize the measurement of different sizes and different shapes imaging area, and widely applicable, easy to disassemble and assemble, improve measurement accuracy without damaging the object.

Description

Technical Field

[0001] This invention relates to the field of rapid capacitance tomography technology, and more specifically to a rapid capacitance tomography device and imaging method with a universal detachable sensor. Background Technology

[0002] Electrical Capacitance Tomography (ECT) measures the capacitance between electrodes arranged along the contour of the imaging region. Based on the sensor's sensitive field characteristics and an inversion algorithm, the dielectric constant distribution of the imaging region is reconstructed. This allows for non-contact imaging of the dielectric constant within structures of arbitrary shapes, making it an ideal non-contact measurement technique. A typical two-dimensional ECT uses an array of n capacitor electrodes arranged along the circumference of a circular, insulated, rigid pipe. Each pair of electrodes forms a capacitor, resulting in a total of m = n*(n-1) / 2 capacitor arrays C. The size of these m capacitors is closely related to the dielectric constant distribution within the pipe. By modeling the sensing characteristics within the pipe, a sensitive field S is obtained, representing the relationship between the dielectric constant and the array capacitance. Based on the sensitive field S, the n array capacitors C, and a specific inversion algorithm, the dielectric constant distribution within the pipe is reconstructed, thus achieving imaging of the pipe's interior.

[0003] In practice, the shape of the ECT imaging area can be circular, square, rectangular, elliptical, triangular, or arbitrary, and its size also varies depending on the imaging area. Existing two-dimensional / three-dimensional capacitance tomography methods require customized sensors for the imaging area of ​​each measurement object. A customized sensor can only be used for one measurement object or occasion, lacking a universal ECT sensor solution applicable to various occasions. Existing technology publications CN112326744A disclose a three-dimensional capacitance tomography signal detection system, and CN111721816A discloses a three-dimensional ECT sensor measurement. Both have single measurement objects and fixed structures, making them unsuitable for universally measuring objects of arbitrary shapes. Existing technology publication CN104858813A discloses a multi-parameter adjustable ECT sensor fixture device, which changes the sensor diameter by adjusting the outer peripheral rods. However, its problem is that the specific dimensions and structure of the sensor cannot be directly obtained from the device, which is inconvenient for subsequent inversion algorithms. Summary of the Invention

[0004] 1. The technical problem to be solved:

[0005] To address the aforementioned technical problems, this invention provides a rapid capacitance tomography imaging device and method with a universal detachable sensor. A fixed structure on the outer periphery secures the connection between the scale rod and the imaging area being measured. A rotatable connection with a spherical hinge is designed between the electrode and the scale rod. By adjusting the extension length of the scale rod and measuring the angle between the scale rod and the spherical hinge, not only can the size of the imaging area be obtained, but the position of the capacitance tomography imaging electrode can also be directly acquired, thus enabling the device to adapt to various imaging areas.

[0006] 2. Technical Solution:

[0007] A rapid capacitance tomography device with a universal detachable sensor is characterized by comprising electrodes, a scale rod, and a rigid support; the rigid support is composed of two detachable support bodies; the assembled support can surround the outside of the area to be imaged; the rigid support is provided with multiple through holes for the scale rod to pass through; the through holes extend outward from the center of the rigid support; the scale rod is a hollow insulated round rod with length markings on its surface, and its end located inside the rigid support is connected to the electrode via a rotatable connecting device; the electrode is a flexible electrode sheet; the shielded signal line of the electrode sheet is connected to the capacitance data acquisition circuit at the outer end via the connecting device and the rod cavity of the scale rod; during imaging, the outer surface of the electrode is attached to the surface of the area to be imaged to form the outline of the imaging area.

[0008] Furthermore, the rigid support is a circular metal support with through holes distributed in a circle on the same plane; during imaging, the extension length of the scale rod and the angle between the scale rod and the electrode are adjusted so that the outer surfaces of multiple electrodes are all attached to the surface of the area to be imaged, forming the outline of the two-dimensional planar imaging area.

[0009] Furthermore, the rigid support is a spherical metal support; the electrode is an array electrode, and each sub-electrode in the array electrode is provided with a corresponding scale rod, and each scale rod is provided with a through hole passing through the rigid support; during imaging, the extension length of the scale rod and the angle between the scale rod and the electrode are adjusted so that the outer surfaces of all sub-electrodes of the array electrode are attached to the surface of the area to be imaged to form the outline of the three-dimensional imaging area.

[0010] Furthermore, a guide tube is sleeved inside the through hole of the rigid support, and the measuring rod passes through the guide tube; the guide tube extends in the direction of extending to the center of the rigid support; the guide tube is provided with fixing bolts for fixing the measuring rod.

[0011] Furthermore, the rotatable connecting device is a spherical hinge connection; the spherical hinge connection specifically includes a spherical end set at the end of the scale rod and a ball socket at the middle position of the outer surface of the electrode; the spherical end is installed in the inner cavity of the ball socket to drive the scale rod to rotate along the ball socket; the surface of the ball socket and the surface of the scale rod are provided with a midline for measuring the angle between the scale rod and the outer surface of the electrode.

[0012] An imaging method for a fast capacitive tomography device with a universal detachable sensor includes the following steps:

[0013] Step 1: Select a rigid support of appropriate shape and size according to the size, shape and dimension of the area to be imaged; disassemble the rigid support, determine the required number of electrodes, and pass the corresponding number of scale rods and electrodes through the corresponding through holes.

[0014] Step 2: After disassembling the rigid bracket, attach it around the pipe to be imaged and then assemble it; adjust the extension of the movable scale rod and the angle between the electrode and the scale rod so that the front of the electrode is in contact with the surface of the pipe, and then fix the scale rod with the fixing bolts; until the front surfaces of all electrodes are in contact with the pipe.

[0015] Step 3: Read the length of all the protruding scale rods; then, using the rigid support with a defined diameter as a reference, determine the coordinates of all electrodes; Step 4: Measure the angle between each scale rod and the outer surface of the electrode; input the coordinates obtained in Step 3 and the angle obtained in Step 4 into the imaging computer to depict the outline and size of the imaging area formed by the electrodes, the location of each electrode within the outline, and the size of the electrodes.

[0016] Step 5: The imaging computer calculates the sensitive field of the capacitance tomography sensor based on the contour and size of the imaging area and the position and size of the electrodes, and the array capacitance acquired by the data acquisition system; the imaging computer can quickly reconstruct the image of the imaging area based on the calculated sensitive field and the acquired array capacitance.

[0017] 3. Beneficial effects:

[0018] (1) The present application provides a fast capacitance tomography imaging device and imaging method with a universal detachable sensor. By using the length scale set on the surface of the scale rod and the size of the rigid support, the size of the imaging area contour can be directly calculated. The device is applicable to imaging areas of any shape and size. At the same time, the contour of the imaging area and the sensor electrode can be directly read by the rotation angle of the spherical rotatable hinge, the sensor size can be determined, and the sensor sensitivity field can be quickly calculated to realize the rapid reconstruction of the dielectric constant distribution image of the measured object at any position.

[0019] (2) The complete structure of this application consists of four parts: electrodes, rotatable spherical hinges, a measuring rod, and a rigid support. The measuring rod is fixed on the rigid support, and the measuring rod is connected to the electrodes through the spherical hinges. The rigid support can be disassembled along the circumference to enable portable measurement and measurement of multiple different objects, and can be used on any measuring object.

[0020] In summary, this invention can measure imaging areas of different sizes and shapes, meeting the needs of situations with numerous measurement objects and varying measurement area sizes and shapes. It also has a wide range of applications, is easy to assemble and disassemble, and improves measurement accuracy without damaging the object. Attached Figure Description

[0021] Figure 1 This is a schematic diagram of the structure for imaging an elliptical region in a specific embodiment;

[0022] Figure 2 This is an enlarged view of the scale rod, electrodes, and imaging area in a specific embodiment;

[0023] Figure 3 This is a schematic diagram illustrating how the imaging contour and size are obtained in a specific embodiment;

[0024] Figure 4 This is a schematic diagram of the structure for imaging a square region in a specific embodiment;

[0025] Figure 5 This is a three-dimensional disassembled view of a single universal sensor in this invention, showing the connection between a single scale rod and an electrode.

[0026] Figure labeling: Electrode 1; Scale rod 2; Rigid support 3; Spherical hinge 4; Imaging area 5; Connecting screw 6; Conduit 7; Fixing screw 8; Shielded signal line 9; Ball head 10; Ball socket 11. Detailed Implementation

[0027] The present invention will now be described in detail with reference to the accompanying drawings.

[0028] A rapid capacitance tomography device with a universal detachable sensor is characterized by comprising an electrode 1, a scale rod 2, and a rigid support 3; the rigid support is composed of two detachable support bodies; the assembled support can surround the outside of the area to be imaged; the rigid support is provided with multiple through holes for the scale rod to pass through; the through holes extend outward from the center of the rigid support; the scale rod is a hollow insulated round rod with length markings on its surface, and its end located inside the rigid support is connected to the electrode via a rotatable connecting device; the electrode is a flexible electrode sheet; the shielded signal line of the electrode sheet is connected to the capacitance data acquisition circuit at the outer end via the connecting device and the rod cavity of the scale rod; during imaging, the outer surface of the electrode is attached to the surface of the area to be imaged to form the outline of the imaging area 5.

[0029] Furthermore, the rigid support is a circular metal support with through holes distributed in a circle on the same plane; during imaging, the extension length of the scale rod and the angle between the scale rod and the electrode are adjusted so that the outer surfaces of multiple electrodes are all attached to the surface of the area to be imaged, forming the outline of the two-dimensional planar imaging area.

[0030] Furthermore, the rigid support is a spherical metal support; the electrode is an array electrode, and each sub-electrode in the array electrode is provided with a corresponding scale rod, and each scale rod is provided with a through hole passing through the rigid support; during imaging, the extension length of the scale rod and the angle between the scale rod and the electrode are adjusted so that the outer surfaces of all sub-electrodes of the array electrode are attached to the surface of the area to be imaged to form the outline of the three-dimensional imaging area.

[0031] Furthermore, a guide tube is sleeved inside the through hole of the rigid support, and the measuring rod passes through the guide tube; the guide tube extends in the direction of extending to the center of the rigid support; the guide tube is provided with fixing bolts for fixing the measuring rod.

[0032] Furthermore, the rotatable connecting device is a spherical hinge 4 connection; the spherical hinge connection specifically includes a spherical end set at the end of the scale rod and a ball socket at the middle position of the outer surface of the electrode; the spherical end is installed in the inner cavity of the ball socket to drive the scale rod to rotate along the ball socket; the surface of the ball socket and the surface of the scale rod are provided with a midline for measuring the angle between the scale rod and the outer surface of the electrode.

[0033] An imaging method for a fast capacitive tomography device with a universal detachable sensor includes the following steps:

[0034] Step 1: Select a rigid support of appropriate shape and size according to the size, shape and dimension of the area to be imaged; disassemble the rigid support, determine the required number of electrodes, and pass the corresponding number of scale rods and electrodes through the corresponding through holes.

[0035] Step 2: After disassembling the rigid bracket, attach it around the pipe to be imaged and then assemble it; adjust the extension of the movable scale rod and the angle between the electrode and the scale rod so that the front of the electrode is in contact with the surface of the pipe, and then fix the scale rod with the fixing bolts; until the front surfaces of all electrodes are in contact with the pipe.

[0036] Step 3: Read the length of all the protruding rods; then, using the rigid support with a defined diameter as a reference, determine the coordinates of all electrodes.

[0037] Step 4: Measure the angle between each scale rod and the outer surface of the electrode; input the coordinates obtained in Step 3 and the angle obtained in this step into the imaging computer to depict the outline and size of the imaging area formed by the electrodes, the location of each electrode in the outline, and the size of the electrodes.

[0038] Step 5: The imaging computer calculates the sensitive field of the capacitance tomography sensor based on the contour and size of the imaging area and the position and size of the electrodes, and the array capacitance acquired by the data acquisition system; the imaging computer can quickly reconstruct the image of the imaging area based on the calculated sensitive field and the acquired array capacitance. Specific implementation examples:

[0040] This embodiment uses eight sensor electrodes and a circular rigid support as an example to illustrate the imaging of an elliptical imaging area (see attached diagram). Figure 1 , 2 3) Square imaging area (attached) Figure 4 This section explains how to create a two-dimensional image.

[0041] As attached Figures 1 to 3 As shown in the figure, the eight sensor electrodes are designated E1-E8. Eight through holes are opened on the rigid support, through which the measuring rod 2 passes. The two components of the rigid support are connected by connecting screws. To ensure the measuring rod remains perpendicular to the support, a guide tube 7 is designed at the opening of the rigid support to ensure the measuring rod always moves along the diameter of the rigid support. A fixing screw 8 is installed on the outer side of the guide tube near the support to ensure the position of the measuring rod and the rigid support can be fixed. The surface of the measuring rod is engraved with graduations for easy reading of the depth to which the measuring rod is inserted into the rigid support.

[0042] The scale rod and the capacitance tomography sensor electrode 1 are connected by a spherical hinge, ensuring that the electrode can rotate at a certain angle to adapt to the contour requirements of different imaging areas 5. The spherical hinge consists of a ball head 10 and a ball socket 11, which rotate to adjust the angle between the electrode and the scale rod. The electrode attached to the spherical hinge can be freely removed and replaced according to the surface shape of the object being measured. In different detection environments, planar or curved electrodes can be replaced depending on the surface condition, ensuring full adhesion between the electrode and the surface of the object being measured. Each electrode is made of flexible material, which can be appropriately changed according to the shape of the object, increasing the contact area between the electrode and the measured plane, thereby improving measurement accuracy.

[0043] The shielded signal line 9 of the capacitance tomography electrode is introduced into the scale rod from the spherical hinge position, and then led from the scale rod to the outside of the rigid support, connecting to the array capacitance data acquisition instrument for data acquisition. To avoid short-circuiting the electrode to the outer shell, the scale rod is made of non-metallic insulating material. The rigid support is made of metal, which ensures the rigidity of the support and also serves as a shield for the capacitance tomography sensor, shielding the imaging area from the influence of external electromagnetic fields.

[0044] As attached Figure 3 As shown, given a fixed electrode width W and rigid support diameter D, the contour of the imaging region enclosed by the eight electrodes and the positions and sizes of the capacitance tomography electrodes can be determined by measuring the length Hx (x=1,…,n, where n is the number of electrodes) of the scale rods extending from the support and the rotation angle θx (x=1,…,n) of the spherical hinge, thus forming a capacitance tomography sensor with defined geometric parameters. After determining the contour of the imaging region and the positions of the sensor electrodes based on all scale rod lengths Hx and the angles θx between each electrode and the scale rods, the sensor sensitivity field S is calculated, and the relationship λ between the sensor dielectric constant distribution g and the sensor output capacitance is quickly established. The dielectric constant distribution within the sensor is reconstructed using a capacitance tomography algorithm. Taking the basic linear back projection (LBP) algorithm as an example, the relationship is:

[0045] g=S T ·λ

[0046] Where λ represents the capacitance combination between all n electrodes, with N = n(n-1) / 2 combinations; g represents the number of pixels with dielectric constant distribution, with M combinations; S represents the sensitive field matrix for a given sensor size, with M×N dimensions; S T Let S be the transpose of S.

[0047] Based on the reconstructed dielectric constant distribution within the sensor, the imaging computer outputs the reconstructed image.

[0048] Although the present invention has been disclosed above with reference to preferred embodiments, these are not intended to limit the present invention. Any person skilled in the art can make various changes or modifications without departing from the spirit and scope of the present invention. Therefore, the scope of protection of the present invention should be defined by the scope of the claims of this application.

Claims

1. A rapid capacitance tomography device with a universal detachable sensor, characterized in that: The system includes electrodes, a scale rod, and a rigid support. The rigid support is composed of two detachable support bodies. The assembled support can surround the outside of the area to be imaged. The rigid support has multiple through holes for the scale rod to pass through. The scale rod extends outward from the center of the rigid support. The scale rod is a hollow, insulated round rod with length markings on its surface. Its end located inside the rigid support is connected to the electrode via a rotatable connecting device. The electrode is a flexible electrode sheet. The shielded signal line of the electrode sheet is connected to the capacitance data acquisition circuit at the outer end via the connecting device and the rod cavity of the scale rod. During imaging, the outer surface of the electrode is attached to the surface of the area to be imaged to form the outline of the imaging area. The rigid support is a spherical metal support; the electrode is an array electrode, and each sub-electrode in the array electrode is provided with a corresponding scale rod, and each scale rod passes through the rigid support through a through hole; during imaging, the extension length of the scale rod and the angle between the scale rod and the electrode are adjusted so that the outer surface of all the sub-electrodes of the array electrode are attached to the surface of the area to be imaged to form the outline of the three-dimensional imaging area.

2. The rapid capacitance tomography device with a universal detachable sensor according to claim 1, characterized in that: The rigid support is a circular metal support with through holes distributed in a circle on the same plane. During imaging, the extension length of the scale rod and the angle between the scale rod and the electrode are adjusted so that the outer surfaces of multiple electrodes are all attached to the surface of the area to be imaged, forming the outline of the two-dimensional planar imaging area.

3. The rapid capacitance tomography device with a universal detachable sensor according to claim 1, characterized in that: A guide tube is sleeved inside the through hole of the rigid support, and the measuring rod passes through the guide tube; the guide tube extends in the direction of extending to the center of the rigid support; the guide tube is provided with fixing bolts for fixing the measuring rod.

4. The rapid capacitance tomography device with a universal detachable sensor according to claim 1, characterized in that: The rotatable connection device is a spherical hinge connection; the spherical hinge connection specifically includes a spherical end set at the end of the scale rod and a ball socket at the middle position of the outer surface of the electrode; the spherical end is installed in the inner cavity of the ball socket to drive the scale rod to rotate along the ball socket; the surface of the ball socket and the surface of the scale rod are provided with a midline for measuring the angle between the scale rod and the outer surface of the electrode.

5. An imaging method for a fast capacitance tomography apparatus with a universal detachable sensor, using the apparatus as described in any one of claims 1 to 4, characterized in that: Includes the following steps: Step 1: Select a rigid support of appropriate shape and size based on the size, shape, and dimensions of the area to be imaged. Disassemble the rigid support, determine the required number of electrodes, and pass the corresponding number of scale rods and electrodes through the corresponding through holes; Step 2: After disassembling the rigid bracket, fit it around the pipe to be imaged and then assemble it; adjust the extension of the movable scale rod and the angle between the electrode and the scale rod so that the front of the electrode is in contact with the surface of the pipe, and then fix the scale rod with the fixing bolts; until the front surfaces of all electrodes are in contact with the imaging area. Step 3: Read the length of all the protruding scale rods; then, using the rigid support with a defined diameter as a reference, determine the coordinates of all electrodes; Step 4: Measure the angle between each scale rod and the outer surface of the electrode; input the coordinates obtained in Step 3 and the angle obtained in Step 4 into the imaging computer to depict the outline and size of the imaging area formed by the electrodes, the location of each electrode within the outline, and the size of the electrodes. Step 5: The imaging computer calculates the sensitive field of the capacitance tomography sensor based on the contour and size of the imaging area and the position and size of the electrodes, and the array capacitance acquired by the data acquisition system; the imaging computer can quickly reconstruct the image of the imaging area based on the calculated sensitive field and the acquired array capacitance.

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