Fuel rod size measurement method and device based on data fusion

Abstract

The invention discloses a fuel rod size measurement method and device based on data fusion. The method comprises the following steps: scanning a fuel rod by using a laser contourgraph to obtain a first length and a first straightness of the fuel rod; photographing the fuel rod by using the image measuring instrument so as to obtain a second length and a second straightness of the fuel rod; and fusing data obtained by the laser contourgraph and the image measuring instrument to obtain a third length and a third straightness of the fuel rod. The laser contourgraph and the image measuring instrument are used for measuring the length and the straightness, the product measuring efficiency is improved, data measured by the laser contourgraph and the image measuring instrument are subjected to data fusion processing, random errors are reduced, and the measuring precision is improved; and through the weighted average method, the measurement reliability and accuracy are remarkably improved while the real-time performance of fuel rod size measurement is ensured.

Description

Technical Field

[0001] The present invention relates to the field of fuel rod detection, and particularly to a method and device for measuring the size of a fuel rod based on data fusion. Background Art

[0002] In the field of nuclear power generation, nuclear fuel rods are one of the important components. To ensure the safe and reliable operation of nuclear fuel rods, the size of the fuel rods, including length, straightness, etc., needs to be measured during the production process. Existing fuel rod size measurement equipment needs to measure length and straightness separately, and special equipment is required for measurement, and the degree of automation is not high. Manual measurement leads to relatively large errors. Therefore, improvements need to be made to the existing technology. Summary of the Invention

[0003] Aiming at the problems existing in the prior art, the present invention provides a method and device for measuring the size of a fuel rod based on data fusion, aiming to reduce random errors and improve measurement accuracy.

[0004] To achieve the above object, the specific solutions of the present invention are as follows:

[0005] A method for measuring the size of a fuel rod based on data fusion includes the following steps:

[0006] S1: Scanning the fuel rod with a laser profiler to obtain the first length and the first straightness of the fuel rod;

[0007] S2: Taking a photo of the fuel rod with an image measuring instrument to obtain the second length and the second straightness of the fuel rod;

[0008] S3: Fusing the data obtained by the laser profiler and the image measuring instrument to obtain the third length and the third straightness of the fuel rod.

[0009] Preferably, the step S1 includes the following steps:

[0010] S101: The laser profiler scans along the axis direction of the fuel rod to generate a 3D point cloud;

[0011] S102: Cutting along the vertical plane direction where the axis of the 3D point cloud is located to obtain a vertical section;

[0012] S103: Calculating the distance between the edge of the vertical section and the reference line to obtain the first straightness;

[0013] S104: Calculating the horizontal length of the vertical section, which is the first length of the fuel rod.

[0014] Preferably, the step S2 includes the following steps:

[0015] S201: The image measuring instrument takes continuous photos along the axis of the fuel rod to obtain the projection pictures of each part of the fuel rod;

[0016] S202: Stitch the projection pictures to form a complete image of the fuel rod;

[0017] S203: Calculate the second straightness and the second length of the upper edge of the complete image.

[0018] Preferably, in the step S3, the data fusion method for obtaining the third length and the third straightness of the fuel rod is the weighted average method.

[0019] Preferably, the step S3 includes the following steps:

[0020] S301: The laser profiler and the image measuring instrument calibrate the weight data of the same standard part, and calculate the error variance respectively where i is the laser profiler or the image measuring instrument;

[0021] S302: Allocate weights according to the error variance The smaller the variance, the greater the weight;

[0022] S303: Normalize the weights Ensure that the sum of all weights is 1;

[0023] S304: Output the measurement result through weighted fusion

[0024] The present invention also provides a fuel rod size measuring device based on data fusion, including a linear motor, a laser profiler, an image measuring instrument, and a support structure. A double mover is assembled on the linear motor, and the laser profiler and the image measuring instrument are assembled on the double mover.

[0025] Adopting the technical solution of the present invention has the following beneficial effects:

[0026] Using a laser profiler and an image measuring instrument to measure the length and straightness improves the product measurement efficiency. The data measured by the two are then processed by data fusion to reduce random errors and improve the measurement accuracy; through the weighted average method, while ensuring the real-time performance of the fuel rod size measurement, the measurement reliability and accuracy are significantly improved. Description of the Drawings

[0027] Figure 1 It is the overall flowchart of the present invention;

[0028] Figure 2 It is the flowchart of step S1 of the present invention;

[0029] Figure 3 It is the schematic diagram of step S1 of the present invention;

[0030] Figure 4 Flow chart of the method for obtaining the first straightness of the present invention;

[0031] Figure 5 Schematic diagram of the method for obtaining the first straightness of the present invention;

[0032] Figure 6 Flow chart of the method for obtaining the first length of the present invention;

[0033] Figure 7 Schematic diagram of the method for obtaining the first length of the present invention;

[0034] Figure 8 Flow chart of step S2 of the present invention;

[0035] Figure 9 Schematic diagram of step S2 of the present invention;

[0036] Figure 10 Flow chart of the method for obtaining the second length of the present invention;

[0037] Figure 11 Schematic diagram of the method for obtaining the second length of the present invention;

[0038] Figure 12 Flow chart of step S3 of the present invention;

[0039] Figure 13 Schematic structural diagram of the device of the present invention. Detailed implementation manners

[0040] The present invention will be further described below in conjunction with the accompanying drawings and specific embodiments.

[0041] Refer to Figure 1 , the present invention provides a method for measuring the size of a fuel rod based on data fusion, including the following steps:

[0042] S1: Use a laser profiler to scan the fuel rod to obtain the first length and the first straightness of the fuel rod;

[0043] S2: Use an image measuring instrument to take pictures of the fuel rod to obtain the second length and the second straightness of the fuel rod;

[0044] S3: Fuse the data obtained by the laser profiler and the image measuring instrument to obtain the third length and the third straightness of the fuel rod.

[0045] Refer to Figures 2 to 3 , the step S1 includes the following steps:

[0046] S101: The laser profiler scans along the axis direction of the fuel rod to generate a 3D point cloud (the view of this step is the front view);

[0047] S102: Cut along the vertical plane direction where the 3D point cloud axis is located to obtain a vertical section (the view of this step is the top view);

[0048] S103: Calculate the distance between the edge of the vertical section and the reference line to obtain the first straightness (the view of this step is the front view);

[0049] S104: Calculate the length of the vertical section in the horizontal direction, which is the first length of the fuel rod (the view of this step is the front view).

[0050] Refer to Figures 4 to 5 , in the step S103, the method for obtaining the first straightness is:

[0051] S1031: Perform edge detection on the upper edge of the pipe to find several points on the edge;

[0052] S1032: Fit these points into a straight line by the least squares method; assume that the straight line obtained according to the least squares method is y = ax + b, and this straight line is the reference line;

[0053] S1033: Obtain the perpendicular distance between these points and the fitted straight line; formula: d i is the perpendicular distance from the i-th point to the straight line, (x i ,y i ) is the coordinate of the i-th point;

[0054] S1034: Take the sum of the absolute values of the maximum positive and negative deviations as the straightness; formula: straightness = max(di) - min(d i )(d i is the deviation of each point).

[0055] Refer to Figures 6 to 7 , in the step S104, the method for obtaining the first length is:

[0056] S1041: Perform edge detection on both ends of the pipe to find several points on the edge;

[0057] S1042: Fit the points at one end into a plane by the least squares method; assume that the plane obtained according to the least squares method is Ax + By + Cz + D = 0, where A, B, and C are the components of the normal vector and D is the constant term;

[0058] S1043: Obtain the perpendicular distance from the points at the other end to the plane; formula: d i is the perpendicular distance from the i-th point to the plane, (x i ,y i ,z i ) is the coordinate of the i-th point;

[0059] S1044: Average these distances to finally obtain the first length of the pipe; formula: d’ is the first length of the pipe.

[0060] Refer to Figures 8 to 9 , and the step S2 includes the following steps:

[0061] S201: The image measuring instrument takes continuous photos along the axis of the fuel rod to obtain the projection pictures of each part of the fuel rod (the view of this step is the front view);

[0062] S202: Stitch the projection pictures to form a complete image of the fuel rod (the view of this step is the front view);

[0063] S203: Calculate the second straightness and the second length of the upper edge of the complete image.

[0064] In the step S203, the method for calculating the second straightness is the same as the method for calculating the first straightness, which will not be elaborated here;

[0065] Refer to Figures 10 to 11 , and in the step S203, the method for calculating the second length is:

[0066] S2031: Perform edge detection on both ends of the pipe to find several points on the edge;

[0067] S2032: Fit the points at one end into a straight line using the least squares method; assume that the straight line obtained according to the least squares method is y = ax + b;

[0068] S2033: Obtain the perpendicular distance from the points at the other end to the straight line; formula: where d i is the perpendicular distance from the i-th point to the straight line, (x i , y i ) is the coordinate of the i-th point;

[0069] S2034: Average these perpendicular distances to finally obtain the second length of the pipe; formula: d’ is the second length of the pipe.

[0070] In the step S3, the data fusion method for obtaining the third length and the third straightness of the fuel rod is the weighted average method.

[0071] Refer to Figure 12 , and the step S3 includes the following steps:

[0072] S301: The laser profiler and the image measuring instrument calibrate the weight data for the same standard part, and calculate the error variance respectively where i is a laser profiler or an image measuring instrument;

[0073] S302: Assign weights according to the error variance The smaller the variance, the larger the weight;

[0074] S303: Normalize the weights Ensure that the sum of all weights is 1;

[0075] S304: Output the measurement result through weighted fusion

[0076] Refer to Figure 13 , the present invention also provides a fuel rod size measuring device based on data fusion, including a linear motor 1, a laser profiler 2, an image measuring instrument 3, and a support structure 4. A double mover 5 and 6 are assembled on the linear motor 1. The laser profiler 2 and the image measuring instrument 3 are respectively assembled on the double movers 5 and 6. The fuel rod 7 to be detected is placed on the support structure 4. During measurement, the linear motor 1 drives the double movers 5 and 6 to move. The laser profiler 2 and the image measuring instrument 3 are respectively driven by the double movers 5 and 6 to move along the axis direction of the fuel rod 7. Among them, the laser profiler 2 scans along the axis direction of the fuel rod 7 to generate a 3D point cloud, and the image measuring instrument 3 continuously takes pictures along the axis direction of the fuel rod 7 to obtain the projection pictures of each part of the fuel rod 7.

[0077] The above are only the preferred embodiments of the present invention, and do not limit the patent scope of the present invention accordingly. Any equivalent structural transformation made under the inventive concept of the present invention by using the content of the specification and drawings of the present invention, or any direct / indirect application in other related technical fields, is included in the protection scope of the present invention.

Claims

1. A method for measuring the size of a fuel rod based on data fusion, characterized in that, It includes the following steps: S1: Use a laser profiler to scan the fuel rod to obtain the first length and the first straightness of the fuel rod; S2: Use an image measuring instrument to take pictures of the fuel rod to obtain the second length and the second straightness of the fuel rod; S3: Integrate the data obtained by the laser profiler and the image measuring instrument to obtain the third length and the third straightness of the fuel rod.

2. The method for measuring the size of a fuel rod based on data fusion according to claim 1, wherein The step S1 includes the following steps: S101: The laser profiler scans along the axis direction of the fuel rod to generate 3D point clouds; S102: Cut along the vertical plane where the 3D point cloud axis is located to obtain a vertical section; S103: Calculate the distance between the edge of the vertical section and the reference line to obtain the first straightness; S104: Calculate the horizontal length of the vertical section, which is the first length of the fuel rod.

3. The method for measuring the size of a fuel rod based on data fusion according to claim 1, wherein The step S2 includes the following steps: S201: The image measuring instrument continuously takes pictures along the axis of the fuel rod to obtain the projection pictures of each part of the fuel rod; S202: Stitch the projection pictures to form a complete image of the fuel rod; S203: Calculate the second straightness and the second length of the upper edge of the complete image.

4. The method for measuring the size of a fuel rod based on data fusion according to claim 1, characterized in that, In the step S3, the data integration method for obtaining the third length and the third straightness of the fuel rod is the weighted average method.

5. The method for measuring the size of a fuel rod based on data fusion according to claim 4, wherein The step S3 includes the following steps: S301: The laser profiler and the image measuring instrument perform weighted data calibration on the same standard part, and calculate the error variance respectively where i is the laser profiler or the image measuring instrument; S302: Allocate weights according to the error variance The smaller the variance, the greater the weight; S303: Normalize weights Ensure that the sum of all weights is 1; S304: Output the measurement result after weighted fusion 6. A fuel rod size measuring device based on data fusion, characterized in that, It includes a linear motor, a laser profiler, an image measuring instrument, and a support structure. A double mover is assembled on the linear motor, and the laser profiler and the image measuring instrument are assembled on the double mover.

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