CN114723942A - Method, device and equipment for detecting size of lithium battery pole piece and storage medium - Google Patents
Method, device and equipment for detecting size of lithium battery pole piece and storage medium Download PDFInfo
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Abstract
The embodiment of the invention discloses a method and a device for detecting the size of a lithium battery pole piece, computer equipment and a computer readable storage medium, wherein the method comprises the following steps: acquiring a target detection image of a pole piece to be detected; determining an ROI (region of interest) in a target detection image, and performing edge point detection on the ROI to acquire at least one first edge point; screening based on at least one first edge point, and determining at least two second edge points; performing straight line fitting on the basis of the screened at least two second edge points, and determining a target fitting straight line according to a straight line fitting result and a circumscribed rectangle of the at least one first edge point, wherein the target fitting straight line comprises a first fitting straight line in the first detection image and a second fitting straight line in the second detection image; and determining the width information of the pole piece to be detected according to the first fitting straight line and the second fitting straight line. By adopting the invention, the size of the lithium battery in the width direction can be accurately detected.
Description
Technical Field
The invention relates to the technical field of lithium batteries and the technical field of image processing, in particular to a method and a device for detecting the size of a lithium battery pole piece, computer equipment and a computer-readable storage medium.
Background
Lithium batteries are rechargeable batteries that use graphite or other carbon materials as the negative electrode and lithium-containing compounds as the positive electrode. It is a battery using a nonaqueous electrolyte solution, which uses lithium metal or a lithium alloy as a positive/negative electrode material. With the rapid development of new energy lithium batteries, lithium batteries have been widely used in the fields of mobile electronic products, electric vehicles, digital electronic products, medical electronic devices, security and the like, so that the quality of the lithium batteries in production and manufacturing, the safety of the lithium batteries and the like are more and more important.
The production and manufacture of the lithium battery are connected by a plurality of process steps, including three stages of pole piece manufacture, battery assembly and liquid injection, each stage can be divided into a plurality of key processes, and each step can greatly influence the performance of the battery.
The pole piece mainly comprises a pole lug and a theme, wherein the manufacturing process of the pole piece mainly comprises the following steps:
coating: uniformly coating the prepared slurry on the surface of the substrate;
baking: drying and drying to obtain a film roll, and preparing for the next working procedure;
rolling: uniformly rolling the pole piece to the thickness required by the process;
laser slitting: cutting off the electrode lugs of the treated coating material according to a specified size, cutting the rolled film into a plurality of pole pieces with the width meeting the technological requirement, and rolling the pole pieces in order;
high-speed die cutting: further cutting the coating material treated in the previous procedure to uniformly cut the coating material into individual laminations;
laminating: alternately stacking the prefabricated positive and negative pole pieces by using diaphragms to form a Z-shaped laminated battery cell;
packaging: and (4) putting the battery core into an aluminum plastic film for heat sealing.
In order to ensure that the pole piece meeting the process requirements can be produced by laser cutting, the width of the pole piece in the process needs to be measured, and the deviation of cutting by a cutter is prevented. However, the accuracy of the scheme for measuring the width of the pole piece in the related art is insufficient, so that the performance of the lithium battery generated based on the corresponding measurement of the width of the pole piece has a problem.
Disclosure of Invention
In view of the above, it is necessary to provide a method and an apparatus for detecting the size of a lithium battery pole piece, a computer device, and a computer-readable storage medium.
In a first aspect of the present invention, a method for detecting a size of a lithium battery electrode tab is provided, where the method includes:
acquiring a target detection image of a pole piece to be detected, wherein the target detection image comprises a first detection image containing a first boundary and a second detection image containing a second boundary of the pole piece to be detected, which are acquired by a first camera device and a second camera device respectively, and the first boundary and the second boundary are two opposite boundaries in the width direction of the pole piece to be detected;
determining an ROI (region of interest) in a target detection image, and performing edge point detection on the ROI to acquire at least one first edge point;
screening based on at least one first edge point, and determining at least two second edge points;
performing straight line fitting on the basis of the screened at least two second edge points, and determining a target fitting straight line according to a straight line fitting result and a circumscribed rectangle of the at least one first edge point, wherein the target fitting straight line comprises a first fitting straight line in the first detection image and a second fitting straight line in the second detection image;
and determining the width information of the pole piece to be detected according to the first fitting straight line and the second fitting straight line.
Optionally, the step of determining an ROI in the target detection image, performing edge point detection on the ROI, and obtaining at least one first edge point further includes:
determining an ROI (region of interest) in the target detection image according to the target detection image;
performing edge point detection on the target detection image based on a scanning sequence corresponding to the target detection image to obtain at least one edge point;
wherein the step of performing edge point detection on the target detection image based on the scanning sequence corresponding to the target detection image to obtain at least one edge point further comprises:
determining gray gradient amplitudes of pixel points in the target detection image based on a scanning sequence corresponding to the target detection image, and determining at least one first edge point in the target detection image by comparing the gray gradient amplitudes with a preset gradient threshold.
Optionally, the step of performing screening based on at least one first edge point and determining at least two second edge points further includes:
traversing all the first edge points, and calculating two vector cosine values corresponding to the traversed first edge points;
and taking the traversed first edge point as the second edge point under the condition that the calculated cosine values of the two vectors are greater than a preset cosine threshold value.
Optionally, the step of performing line fitting based on the screened at least two second edge points, and determining a target fitting straight line according to a result of the line fitting and a circumscribed rectangle of the at least one first edge point further includes:
determining a plurality of first fitted straight lines corresponding to the at least two second edge points through a straight line fitting algorithm, and determining a second fitted straight line in the plurality of first fitted straight lines based on the distances between all the second edge points and the determined first fitted straight lines and a least square method;
determining a circumscribed rectangle corresponding to the at least one first edge point, and determining 2 intersection points based on the intersection of the second fitted straight line and the top edge and the bottom edge of the circumscribed rectangle;
determining a target fitting straight line according to the 2 intersection points;
and the target fitting straight line is a first straight line between the pole piece to be detected and the roller.
Optionally, the step of determining the width information of the pole piece to be detected according to the first fitted straight line and the second fitted straight line further includes:
performing binarization processing on the target detection image based on a preset binarization gray level threshold value;
and for the image obtained by binarization processing, executing the steps of screening based on at least one first edge point, determining at least two second edge points, performing straight line fitting based on the screened at least two second edge points, and determining a target fitting straight line according to the result of the straight line fitting and the circumscribed rectangle of the at least one first edge point so as to obtain a second straight line between the roller and the ceramic and a third straight line between the ceramic and the pole piece coating.
Optionally, the step of determining the width information of the pole piece to be detected according to the first fitted straight line and the second fitted straight line further includes:
and calculating the width information of the pole piece to be detected according to the first straight line, the second straight line and the third straight line.
Optionally, the step of calculating the width information of the pole piece to be detected according to the first straight line, the second straight line, and the third straight line further includes:
calculating the width information of the pole piece coating according to the distance from the first straight line to the third straight line;
calculating width information of the ceramic according to the distance from the second straight line to the third straight line;
and determining the width information of the pole piece to be detected according to the width information of the pole piece coating and the width information of the ceramic.
In a second aspect of the present invention, there is provided a device for detecting a size of a lithium battery electrode tab, wherein the device includes:
the system comprises an image acquisition module, a detection module and a detection module, wherein the image acquisition module is used for acquiring a target detection image of a pole piece to be detected, the target detection image comprises a first detection image containing a first boundary and a second detection image containing a second boundary, the first detection image and the second detection image are acquired by a first camera device and a second camera device respectively, and the first boundary and the second boundary are two opposite boundaries in the width direction of the pole piece to be detected;
the edge point detection module is used for determining an ROI (region of interest) in the target detection image, carrying out edge point detection on the ROI and acquiring at least one first edge point;
the edge point screening module is used for screening based on at least one first edge point and determining at least two second edge points;
the line fitting module is used for performing line fitting on the basis of the screened at least two second edge points, and determining a target fitting line according to a line fitting result and a circumscribed rectangle of the at least one first edge point, wherein the target fitting line comprises a first fitting line in the first detection image and a second fitting line in the second detection image;
and the width information determining module is used for determining the width information of the pole piece to be detected according to the first fitting straight line and the second fitting straight line.
In a third aspect of the present invention, there is provided a computer device, including a memory and a processor, where the memory has an executable code, and when the executable code runs on the processor, the computer device implements the method for detecting the size of the lithium battery pole piece as described above.
In a fourth aspect of the present invention, a computer-readable storage medium is provided, where the computer-readable storage medium is used for storing a computer program, and the computer program is used for executing the method for detecting the size of the lithium battery pole piece.
The embodiment of the invention has the following beneficial effects:
after the size detection method, the size detection device, the computer equipment and the computer-readable storage medium of the lithium battery pole piece are adopted, under the condition that width information of the pole piece of the lithium battery needs to be detected, a target detection image of the pole piece to be detected is obtained, wherein the target detection image comprises a first detection image containing a first boundary and a second detection image containing a second boundary of the pole piece to be detected, which are acquired by a first camera device and a second camera device respectively, and the first boundary and the second boundary are two opposite boundaries in the width direction of the pole piece to be detected; determining an ROI (region of interest) in a target detection image, and performing edge point detection on the ROI to acquire at least one first edge point; screening based on at least one first edge point, and determining at least two second edge points; performing straight line fitting on the basis of the screened at least two second edge points, and determining a target fitting straight line according to a straight line fitting result and a circumscribed rectangle of the at least one first edge point, wherein the target fitting straight line comprises a first fitting straight line in the first detection image and a second fitting straight line in the second detection image; and determining the width information of the pole piece to be detected according to the first fitting straight line and the second fitting straight line. That is to say, in the embodiment of the present invention, the improved least square method is used to perform the line fitting, so that the line corresponding to the edge point can be accurately detected, the accuracy of the pole piece width detection is improved, and the measurement error is reduced.
Drawings
In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below, it is obvious that the drawings in the following description are only some embodiments of the present invention, and for those skilled in the art, other drawings can be obtained according to the drawings without creative efforts.
Wherein:
FIG. 1 is a schematic flow chart illustrating a method for detecting the size of a lithium battery electrode tab according to an embodiment;
FIG. 2 is a schematic diagram of a right image of a pole piece to be detected in one embodiment;
FIG. 3 is a diagram illustrating a right image of a pole piece to be detected in one embodiment;
FIG. 4 is a schematic view of a left image of a pole piece to be detected in one embodiment;
FIG. 5 is a schematic diagram of a left image of a pole piece to be detected in one embodiment;
FIG. 6 is a diagram illustrating a right-side image and a left-side image of a pole piece to be detected in one embodiment;
FIG. 7 is a schematic diagram of left and right images of a pole piece to be detected in one embodiment;
FIG. 8 is a schematic flow chart illustrating a process for detecting the dimensions of a lithium battery electrode tab according to an embodiment;
FIG. 9 is a schematic structural diagram of a size detection apparatus for a lithium battery electrode tab in an embodiment;
fig. 10 is a schematic structural diagram of a computer device for executing the above size detection method for a lithium battery pole piece in one embodiment.
Detailed Description
In order to make the technical solutions of the present application better understood, the technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application, and it is obvious that the described embodiments are only a part of the embodiments of the present application, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present application.
The terms "first," "second," "third," "fourth," and the like in the description and in the claims of the present application and in the drawings described above, if any, are used for distinguishing between similar elements and not necessarily for describing a particular sequential or chronological order. It is to be understood that the data so used is interchangeable under appropriate circumstances such that the embodiments of the application described herein are capable of operation in sequences other than those illustrated or described herein. Furthermore, the terms "comprises," "comprising," and "having," and any variations thereof, are intended to cover a non-exclusive inclusion, such that a process, method, system, article, or apparatus that comprises a list of steps or elements is not necessarily limited to those steps or elements expressly listed, but may include other steps or elements not expressly listed or inherent to such process, method, article, or apparatus.
In this embodiment, a method for detecting the size of a lithium battery pole piece is provided, and the method may be performed in an industrial scene, for example, in a production line of a lithium battery pole piece, a camera is arranged on the production line to acquire an image of the lithium battery pole piece on the production line, and then the width of the corresponding lithium battery pole piece is determined based on image recognition, so that laser cutting can be accurately performed based on the detected width in a subsequent process, thereby improving the performance of the lithium battery and reducing the defective rate of the lithium battery.
In this embodiment, the implementation of the method for detecting the size of the lithium battery pole piece may be based on a computer device connected to a camera that collects an image of the lithium battery pole piece to be detected, where the computer device may be a control device of a product line or a server connected to the product line, and is not limited in this embodiment.
Specifically, referring to fig. 1, fig. 1 shows a schematic flow chart of a size detection method for a lithium battery pole piece. Specifically, the method for detecting the size of the lithium battery pole piece comprises the following steps as shown in fig. 1:
step S101: the method comprises the steps of obtaining a target detection image of a pole piece to be detected, wherein the target detection image comprises a first detection image containing a first boundary and a second detection image containing a second boundary of the pole piece to be detected, which are acquired by a first camera device and a second camera device respectively, and the first boundary and the second boundary are two opposite boundaries in the width direction of the pole piece to be detected.
In this embodiment, a target detection image corresponding to the pole piece to be detected is acquired by the camera device, and is used to detect boundary information of the pole piece to be detected in the width direction, so as to determine the width information of the pole piece to be detected. Specifically, in this embodiment, the detection device includes a first camera device and a second camera device, which are respectively disposed on the left side and the right side of the pole piece to be detected, and are respectively configured to collect a detection image (including a first detection image of a first boundary) including a left boundary of the pole piece to be detected, and a detection image (including a second detection image of a second boundary) including a right boundary of the pole piece to be detected. That is, the first boundary and the second boundary are the left and right boundaries of the pole piece to be detected, that is, the opposite 2 boundaries of the pole piece to be detected in the width direction.
In this embodiment, it is necessary to perform size detection on the left boundary and the right boundary of the pole piece according to the first detection image and the second detection image, respectively, so as to determine size information of the pole piece to be detected in the width direction.
Step S102: and determining an ROI (region of interest) in the target detection image, and performing edge point detection on the ROI to acquire at least one first edge point.
In this embodiment, it is necessary to perform processing separately for the first detection image and the second detection image. Determining an ROI (region of interest) in the target detection image according to the target detection image; performing edge point detection on the target detection image based on a scanning sequence corresponding to the target detection image to obtain at least one edge point; wherein the step of performing edge point detection on the target detection image based on the scanning sequence corresponding to the target detection image to obtain at least one edge point further comprises: determining gray gradient amplitudes of pixel points in the target detection image based on a scanning sequence corresponding to the target detection image, and determining at least one first edge point in the target detection image by comparing the gray gradient amplitudes with a preset gradient threshold.
The second detection image is taken as an example (here, the second detection image may be set to be an image including a right boundary captured by a second camera device arranged on the right side of the pole piece to be detected).
For the second inspection image (for the right image), it is necessary to first inspect a first straight line (straight line L) between the pole piece to be inspected and the roller.
In a specific implementation, the ROI area in the second detected image needs to be determined first, and the right image is obtained. Specifically, as shown in fig. 2-3, fig. 2 shows a schematic diagram of the right image, and fig. 3 shows a schematic diagram of the right image.
And further detecting edge points of the obtained ROI.
Wherein, the detection direction of the edge point is determined according to the detection image, and here, because it is the right image, the detection direction of the edge point (the scanning order corresponding to the target detection image) is from right to left; if it is the left-left image, the detection direction of its edge points is from left to right.
For the right image, for each row of pixel points, the detection of the edge points needs to be performed from right to left, so as to determine the edge points in each row. And the detection of the edge points is obtained by calculation according to the gradient amplitude of the pixel points.
Specifically, for any pixel point, the sum a1 of the gray values of the last two columns is calculated, then the sum a2 of the gray values of the first two columns is calculated, finally the difference between the two is compared with a set gradient threshold, and if the difference is greater than the set gradient threshold, the pixel point is an edge point.
Is provided with
In order to be the threshold value of the gradient,
for each pixel gray value, the edge point of each line is calculated as:
that is, in the case that the scanning direction is from right to left, the edge point is the pixel point corresponding to the i-2 column.
In another embodiment, for the left image, the scanning direction is from left to right, and the corresponding edge point is the pixel point corresponding to the (i + 2) th column.
Step S103: and screening based on the at least one first edge point, and determining at least two second edge points.
For at least one first edge point obtained in step S102, further screening is required. Here, outlier screening may be performed. Specifically, the edge points are screened by whether the cosine value of the included angle between the two vectors is greater than a preset cosine threshold value, so that at least 2 second edge points are obtained.
In specific execution, for each first edge point, two vector cosine values corresponding to the first edge point need to be calculated respectively; and then, under the condition that the two vector cosine values obtained by calculation are larger than a preset cosine threshold value, taking the traversed first edge point as the second edge point, otherwise, not taking the traversed first edge point as the second edge point, and finally finishing the screening from the first edge point to the second edge point.
Specifically, the two vector cosine value calculation formula is as follows:
. Wherein for each first edge point, the corresponding vectors AB and CA are first determined. Wherein, AB: taking the first k points and the last k points, and taking point as the total point number, then the coordinates of the vector AB: subtracting the x coordinate of the ith point from the x coordinate of the ith + K point, and calculating the Y coordinate in the same way;
namely:
then the formula for calculating the two vector cosine values corresponding to the first edge point is:
then, if the cosine value cos θ obtained through calculation is larger than a set threshold (for example, 0.9), selecting the ith point, the (i + K) th point and the (i-K) th point as second edge points, and circulating until all the points are screened, thereby completing the screening of the second edge points.
Step S104: and performing straight line fitting on the basis of the screened at least two second edge points, and determining a target fitting straight line according to a straight line fitting result and a circumscribed rectangle of the at least one first edge point, wherein the target fitting straight line comprises a first fitting straight line in the first detection image and a second fitting straight line in the second detection image.
In specific execution, a plurality of first fitted straight lines corresponding to the at least two second edge points are determined through a straight line fitting algorithm, and a second fitted straight line is determined in the plurality of first fitted straight lines based on the distance between all the second edge points and the determined first fitted straight lines and a least square method; determining a circumscribed rectangle corresponding to the at least one first edge point, and determining 2 intersection points based on the intersection of the second fitted straight line and the top edge and the bottom edge of the circumscribed rectangle; determining a target fitting straight line according to the 2 intersection points; the target fitting straight line is a first straight line L between the pole piece to be detected and the roller.
And performing straight line fitting on at least 2 second edge points screened in the step S103 by using a random sampling consistency principle.
First, a certain number of iterations k is set, for example k = 500.
Then, randomly using 2 second edge points to form a fitting straight line, and calculating the distance from all other second edge points to the fitting straight line:
。
if the calculated distance D is smaller than 1, the point is classified as a local point, the filtering times m1 and the corresponding fitting straight line L1 are recorded, and least square method straight line fitting is carried out on a group of second edge points with the filtering times m1 obtained through loop iteration.
The specific principle is as follows: given data point
Wherein
. Approximate curve solving
. And minimizes the deviation between the approximate curve and the fitted straight line L1. Deviation at approximate pi
. Obtaining a fitting straight line L2 through least square method straight line fitting, then finely adjusting the fitting straight line L2, firstly, utilizing the fitting straight line L2 to calculate the distance from all second edge points to the fitting straight line L2, screening out fine adjustment points if the distance is less than 1, and then respectively fitting by utilizing a least square method: taking a straight line a1 with the point number of the edge points of the first 50%, taking a straight line a2 with the point number between 1/4 and 3/4, taking a straight line a3 with the point number of the last 50%, taking a straight line a4 with all the points, and finally obtaining the distances from all fine adjustment points to four straight lines a1, a2, a3 and a4, if the distance is less than 1, recording the number m2 of the proper points of each straight line, and finally obtaining the maximum one of the proper point numbers m2The straight line is a fitted straight line L2 of the least squares method.
M1 obtained by random sampling consistency is compared with m2 obtained by fitting a straight line by a least square method, one with a larger value is selected, and if m1 is larger, a straight line L = L1 is finally fitted, otherwise, L = L2 is finally fitted.
Furthermore, a circumscribed rectangle corresponding to at least one first edge point is determined, then the fitted straight line L is determined to intersect with the top edge and the bottom edge of the circumscribed rectangle, so as to obtain two intersection points P1, P2, and then a straight line connecting the two intersection points is used as a target fitted straight line (here, the first straight line L).
The process of determining the two intersection points P1 and P2 is as follows:
setting a linear vector
Vector of top side of circumscribed rectangle
The vector of the fitting straight line L is represented as
. Firstly, judging whether two straight lines intersect, wherein the judgment formula is as follows:
and calculating by using the above formula, judging whether the average value is equal to 0, if not, intersecting, and judging whether the intersection is the same or not by using the bottom edge.
The straight lines AB and EF, CD slopes k1, k2 and k3 are obtained, and the slope calculation formula utilizes two-point calculation: set a straight line AB by
Two points, the straight line EF consisting of
The two points are combined to form a composite material,
k1 and k2 are calculated by the above formula, and the intersection point of the two straight lines is calculated by the following formula
The top edge intersection point P1 and the bottom edge intersection point P2 can be obtained by the above formula, and the line connecting P1 and P2 is used as the final detected target fitting straight line (i.e., the first straight line L).
It should be noted that, in the above steps S102 to S104, a corresponding second fitted straight line may be obtained for the right image, and similarly, a first fitted straight line corresponding to the first detection image (left image) may be obtained by solving, where a specific solving process is not described in detail, and a solving process of a second fitted straight line corresponding to the right image may be directly referred to. Please refer to fig. 4-5, wherein fig. 4 is a schematic diagram of a left image, and fig. 5 is a schematic diagram of a left image.
Step S105: and determining the width information of the pole piece to be detected according to the first fitting straight line and the second fitting straight line.
Further, for the right-left image (as shown in fig. 6) corresponding to the right-side image, a second straight line M and a third straight line N need to be further determined. Wherein the second line M is the line between the roller and the ceramic and the third line N is the line between the ceramic and the pole piece coating.
In specific execution, carrying out binarization processing on a target detection image based on a preset binarization gray threshold; for the image resulting from the binarization processing, corresponding fitted straight lines are determined as the second straight line and the third straight line through the above-described steps S102 to S104.
The preset binarization grayscale threshold for performing binarization processing on the right-left image may be 220, and for the obtaining of the third straight line N, the scanning direction for detecting the edge point is from right to left, and the fitted straight line is determined as the third straight line N according to steps S102-S104. For the second straight line M, the scanning direction of the edge point detection is from left to right, and the fitting straight line is determined as the second straight line M according to steps S102 to S104.
Further, for the left and right images, the scanning direction of the straight line between the corresponding roller and the ceramic, and the scanning direction of the straight line between the ceramic and the pole piece coating are opposite to the scanning direction of the right and left images (fig. 7 is a schematic diagram of the left and right images), and other steps are the same and are not repeated herein, which is specifically referred to steps S102 to S104.
After the fitting straight lines are determined, the width information of the pole piece to be detected can be further determined.
Specifically, the width information of the pole piece to be detected is calculated according to a first straight line L, a second straight line M and a third straight line N. In a specific embodiment, width information of the pole piece coating is calculated according to the distance between the first straight line and the third straight line; calculating width information of the ceramic according to the distance between the second straight line and the third straight line; and determining the width information of the pole piece to be detected according to the width information of the pole piece coating and the width information of the ceramic.
The width w3 of the whole pole piece is obtained by respectively calculating the width w1 of the ceramic and the width w2 of the pole piece coating by using the second straight line M, the third straight line N and the first straight line L obtained by the calculation, wherein the distance from the first straight line L to the third straight line N is w2, and the distance from the second straight line M to the third straight line N is w 1. Wherein, the distance calculation formula between the straight lines is as follows:
after the width w1 of the ceramic and the width w2 of the pole piece coating are obtained through calculation, the further formula is carried out
And calculating width information w3 of the pole piece to be detected.
Further, please refer to fig. 8, and fig. 8 shows a schematic flow chart of the size detection method for the lithium battery pole piece. The method comprises the steps of extracting ROI (region of interest) areas of target detection images (a left image and a right image) of a pole piece to be detected respectively, then detecting and screening edge points, and solving a fitting straight line, so that the coating width and the ceramic width of the pole piece to be detected are calculated, and the width information of the pole piece to be detected is determined.
The method comprises the steps of carrying out robust linear fitting estimation by utilizing a random sampling consistency principle, carrying out linear fitting comparison by combining a least square method, selecting an optimal straight line, and finally obtaining a final straight line by obtaining a straight line intersection point.
Further, referring to fig. 9, fig. 9 is a schematic structural diagram of a size detection device for a lithium battery pole piece according to an embodiment of the present invention, and as shown in fig. 9, the device includes:
the image acquisition module 101 is configured to acquire a target detection image of a to-be-detected pole piece, where the target detection image includes a first detection image including a first boundary and a second detection image including a second boundary of the to-be-detected pole piece, which are acquired by a first camera device and a second camera device, respectively, and the first boundary and the second boundary are two opposite boundaries in a width direction of the to-be-detected pole piece;
the edge point detection module 102 is configured to determine an ROI in the target detection image, perform edge point detection on the ROI, and acquire at least one first edge point;
the edge point screening module 103 is configured to perform screening based on at least one first edge point, and determine at least two second edge points;
a straight line fitting module 104, configured to perform straight line fitting based on the screened at least two second edge points, and determine a target fitted straight line according to a result of the straight line fitting and a circumscribed rectangle of the at least one first edge point, where the target fitted straight line includes a first fitted straight line in the first detection image and a second fitted straight line in the second detection image;
and the width information determining module 105 is configured to determine the width information of the pole piece to be detected according to the first fitted straight line and the second fitted straight line.
In an optional embodiment, the edge point detecting module 102 is further configured to determine, according to the target detection image, an ROI region in the target detection image; and carrying out edge point detection on the target detection image based on the scanning sequence corresponding to the target detection image to obtain at least one edge point.
In an optional embodiment, the edge point detecting module 102 is further configured to determine a gray gradient amplitude of a pixel point in the target detection image based on a scanning order corresponding to the target detection image, and determine at least one first edge point in the target detection image by comparing a size between the gray gradient amplitude and a preset gradient threshold.
In an optional embodiment, the edge point filtering module 103 is further configured to traverse all the first edge points, and calculate two vector cosine values corresponding to the traversed first edge points; and under the condition that the two vector cosine values obtained by calculation are greater than a preset cosine threshold value, taking the traversed first edge point as the second edge point.
In an optional embodiment, the straight line fitting module 104 is further configured to determine, through a straight line fitting algorithm, a plurality of first fitted straight lines corresponding to the at least two second edge points, and determine a second fitted straight line in the plurality of first fitted straight lines based on a least square method and distances between all the second edge points and the determined first fitted straight lines; determining a circumscribed rectangle corresponding to the at least one first edge point, and determining 2 intersection points based on the intersection of the second fitted straight line and the top edge and the bottom edge of the circumscribed rectangle; determining a target fitting straight line according to the 2 intersection points; and the target fitting straight line is a first straight line between the pole piece to be detected and the roller.
In an optional embodiment, the width information determining module 105 is further configured to perform binarization processing on the target detection image based on a preset binarization grayscale threshold; and for the image obtained by binarization processing, executing the steps of screening based on at least one first edge point, determining at least two second edge points, performing straight line fitting based on the screened at least two second edge points, and determining a target fitting straight line according to the result of the straight line fitting and the circumscribed rectangle of the at least one first edge point so as to obtain a second straight line between the roller and the ceramic and a third straight line between the ceramic and the pole piece coating.
In an optional embodiment, the width information determining module 105 is further configured to calculate the width information of the pole piece to be detected according to the first straight line, the second straight line, and the third straight line.
In an alternative embodiment, the width information determining module 105 is further configured to calculate width information of the pole piece coating according to a distance between the first straight line and the third straight line; calculating width information of the ceramic according to the distance from the second straight line to the third straight line; and determining the width information of the pole piece to be detected according to the width information of the pole piece coating and the width information of the ceramic.
Fig. 10 shows an internal structure diagram of a computer device for implementing the size detection method of the lithium battery pole piece in one embodiment. The computer device may specifically be a terminal, and may also be a server. As shown in fig. 10, the computer device includes a processor, a memory, and a network interface connected by a system bus. The memory comprises a nonvolatile storage medium and an internal memory. The non-volatile storage medium of the computer device stores an operating system and may also store a computer program which, when executed by the processor, causes the processor to carry out the above-mentioned method. The internal memory may also have a computer program stored thereon, which, when executed by the processor, causes the processor to perform the method described above. Those skilled in the art will appreciate that the architecture shown in fig. 10 is merely a block diagram of some of the structures associated with the disclosed aspects and is not intended to limit the computing devices to which the disclosed aspects apply, as particular computing devices may include more or less components than those shown, or may combine certain components, or have a different arrangement of components.
After the size detection method, the size detection device, the computer equipment and the computer-readable storage medium of the lithium battery pole piece are adopted, under the condition that width information of the pole piece of the lithium battery needs to be detected, a target detection image of the pole piece to be detected is obtained, wherein the target detection image comprises a first detection image containing a first boundary and a second detection image containing a second boundary of the pole piece to be detected, which are acquired by a first camera device and a second camera device respectively, and the first boundary and the second boundary are two opposite boundaries in the width direction of the pole piece to be detected; determining an ROI (region of interest) in a target detection image, and performing edge point detection on the ROI to acquire at least one first edge point; screening based on at least one first edge point, and determining at least two second edge points; performing straight line fitting on the basis of the screened at least two second edge points, and determining a target fitting straight line according to a straight line fitting result and a circumscribed rectangle of the at least one first edge point, wherein the target fitting straight line comprises a first fitting straight line in the first detection image and a second fitting straight line in the second detection image; and determining the width information of the pole piece to be detected according to the first fitting straight line and the second fitting straight line. That is to say, in the embodiment of the present invention, the improved least square method is used to perform the line fitting, so that the line corresponding to the edge point can be accurately detected, the accuracy of the pole piece width detection is improved, and the measurement error is reduced.
It will be understood by those skilled in the art that all or part of the processes of the methods of the embodiments described above can be implemented by a computer program, which can be stored in a non-volatile computer-readable storage medium, and can include the processes of the embodiments of the methods described above when the program is executed. Any reference to memory, storage, database, or other medium used in the embodiments provided herein may include non-volatile and/or volatile memory, among others. Non-volatile memory can include read-only memory (ROM), Programmable ROM (PROM), Electrically Programmable ROM (EPROM), Electrically Erasable Programmable ROM (EEPROM), or flash memory. Volatile memory can include Random Access Memory (RAM) or external cache memory. By way of illustration and not limitation, RAM is available in a variety of forms such as Static RAM (SRAM), Dynamic RAM (DRAM), Synchronous DRAM (SDRAM), Double Data Rate SDRAM (DDRSDRAM), Enhanced SDRAM (ESDRAM), Synchronous Link DRAM (SLDRAM), Rambus Direct RAM (RDRAM), direct bus dynamic RAM (DRDRAM), and memory bus dynamic RAM (RDRAM).
The technical features of the above embodiments can be arbitrarily combined, and for the sake of brevity, all possible combinations of the technical features in the above embodiments are not described, but should be considered as the scope of the present specification as long as there is no contradiction between the combinations of the technical features.
The above-mentioned embodiments only express several embodiments of the present application, and the description thereof is more specific and detailed, but not construed as limiting the scope of the present application. It should be noted that, for a person skilled in the art, several variations and modifications can be made without departing from the concept of the present application, which falls within the scope of protection of the present application. Therefore, the protection scope of the present patent shall be subject to the appended claims.
Claims (10)
1. A size detection method for a lithium battery pole piece is characterized by comprising the following steps:
acquiring a target detection image of a pole piece to be detected, wherein the target detection image comprises a first detection image containing a first boundary and a second detection image containing a second boundary of the pole piece to be detected, which are acquired by a first camera device and a second camera device respectively, and the first boundary and the second boundary are two opposite boundaries in the width direction of the pole piece to be detected;
determining an ROI (region of interest) in a target detection image, and performing edge point detection on the ROI to acquire at least one first edge point;
screening based on at least one first edge point, and determining at least two second edge points;
performing straight line fitting on the basis of the screened at least two second edge points, and determining a target fitting straight line according to a straight line fitting result and a circumscribed rectangle of the at least one first edge point, wherein the target fitting straight line comprises a first fitting straight line in the first detection image and a second fitting straight line in the second detection image;
and determining the width information of the pole piece to be detected according to the first fitting straight line and the second fitting straight line.
2. The method for detecting the size of the lithium battery pole piece according to claim 1, wherein the step of determining the ROI in the target detection image, performing edge point detection on the ROI, and obtaining at least one first edge point further comprises:
determining an ROI (region of interest) in the target detection image according to the target detection image;
performing edge point detection on the target detection image based on a scanning sequence corresponding to the target detection image to obtain at least one edge point;
wherein the step of performing edge point detection on the target detection image based on the scanning sequence corresponding to the target detection image to obtain at least one edge point further comprises:
determining gray gradient amplitudes of pixel points in the target detection image based on a scanning sequence corresponding to the target detection image, and determining at least one first edge point in the target detection image by comparing the gray gradient amplitudes with a preset gradient threshold.
3. The method for detecting the size of the lithium battery pole piece according to claim 1, wherein the step of screening based on at least one first edge point and determining at least two second edge points further comprises:
traversing all the first edge points, and calculating two vector cosine values corresponding to the traversed first edge points;
and taking the traversed first edge point as the second edge point under the condition that the calculated cosine values of the two vectors are greater than a preset cosine threshold value.
4. The method for detecting the size of the lithium battery pole piece according to claim 1, wherein the step of fitting a straight line based on the screened at least two second edge points and determining a target fitting straight line according to the result of the straight line fitting and the circumscribed rectangle of the at least one first edge point further comprises:
determining a plurality of first fitted straight lines corresponding to the at least two second edge points through a straight line fitting algorithm, and determining a second fitted straight line in the plurality of first fitted straight lines based on the distances between all the second edge points and the determined first fitted straight lines and a least square method;
determining a circumscribed rectangle corresponding to the at least one first edge point, and determining 2 intersection points based on the intersection of the second fitted straight line and the top edge and the bottom edge of the circumscribed rectangle;
determining a target fitting straight line according to the 2 intersection points;
and the target fitting straight line is a first straight line between the pole piece to be detected and the roller.
5. The method for detecting the size of the lithium battery pole piece according to claim 4, wherein the step of determining the width information of the pole piece to be detected according to the first fitting straight line and the second fitting straight line further comprises the following steps:
performing binarization processing on the target detection image based on a preset binarization gray level threshold value;
and for the image obtained by binarization processing, executing the steps of screening based on at least one first edge point, determining at least two second edge points, performing straight line fitting based on the screened at least two second edge points, and determining a target fitting straight line according to the result of the straight line fitting and the circumscribed rectangle of the at least one first edge point so as to obtain a second straight line between the roller and the ceramic and a third straight line between the ceramic and the pole piece coating.
6. The method for detecting the size of the lithium battery pole piece according to claim 5, wherein the step of determining the width information of the pole piece to be detected according to the first fitting straight line and the second fitting straight line further comprises the following steps:
and calculating the width information of the pole piece to be detected according to the first straight line, the second straight line and the third straight line.
7. The method for detecting the size of the lithium battery pole piece according to claim 6, wherein the step of calculating the width information of the pole piece to be detected according to the first straight line, the second straight line and the third straight line further comprises the following steps:
calculating the width information of the pole piece coating according to the distance from the first straight line to the third straight line;
calculating width information of the ceramic according to the distance from the second straight line to the third straight line;
and determining the width information of the pole piece to be detected according to the width information of the pole piece coating and the width information of the ceramic.
8. The utility model provides a size detection device of lithium-ion battery pole piece, its characterized in that, the device includes:
the system comprises an image acquisition module, a detection module and a detection module, wherein the image acquisition module is used for acquiring a target detection image of a pole piece to be detected, the target detection image comprises a first detection image containing a first boundary and a second detection image containing a second boundary, the first detection image and the second detection image are acquired by a first camera device and a second camera device respectively, and the first boundary and the second boundary are two opposite boundaries in the width direction of the pole piece to be detected;
the edge point detection module is used for determining an ROI (region of interest) in the target detection image, carrying out edge point detection on the ROI and acquiring at least one first edge point;
the edge point screening module is used for screening based on at least one first edge point and determining at least two second edge points;
the line fitting module is used for performing line fitting on the basis of the screened at least two second edge points, and determining a target fitting line according to a line fitting result and a circumscribed rectangle of the at least one first edge point, wherein the target fitting line comprises a first fitting line in the first detection image and a second fitting line in the second detection image;
and the width information determining module is used for determining the width information of the pole piece to be detected according to the first fitting straight line and the second fitting straight line.
9. A computer device, characterized in that the computer device comprises a memory and a processor, the memory has an executable code, and when the executable code runs on the processor, the computer device implements the size detection method of the lithium battery pole piece according to any one of claims 1 to 7.
10. A computer-readable storage medium for storing a computer program for executing the method for detecting the size of a lithium battery pole piece according to any one of claims 1 to 7.
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