Image acquisition method and system

Abstract

Embodiments of the present disclosure disclose an image acquisition method and system. The method comprises: receiving a first detection signal sent by a position sensor upon detecting a tab on a coil material; acquiring a first pulse count emitted by an encoder disposed on an unwinding roller within the time between the first detection signal and a second detection signal, wherein the second detection signal is a detection signal sent by the position sensor and temporally adjacent to the first detection signal; on the basis of the first pulse count, a preset weight parameter, and a first distance pulse count, determining a total accumulated pulse count for triggering a camera to perform photography, wherein the weight parameter is used to characterize relative positional information between the position at which the coil material is photographed and a first tab in the winding turn in which the current tab is located, and the first distance pulse count is used to characterize a distance between the camera and the position sensor; and on the basis of the total accumulated pulse count, triggering the camera to photograph the coil material.

Description

Image acquisition method and system

[0001] Cross-reference to related applications

[0002] The present disclosure is based on and claims priority to Chinese Patent Application No. 202410825750.6, filed on June 24, 2024, entitled “Image acquisition method and system”, the entire contents of which are incorporated herein by reference. TECHNICAL FIELD

[0003] The present disclosure relates to, but is not limited to, the field of lithium battery detection, and in particular to an image acquisition method and system. BACKGROUND

[0004] Power batteries are increasingly widely used in life and industry. For example, new energy vehicles equipped with power batteries have been widely used. In addition, batteries are also increasingly used in the field of energy storage and the like.

[0005] In the production process of power batteries, the front and back surfaces of the film-coated area need to be visually detected. However, the winding speed of the winding equipment is non-uniform during the winding from the winding to the winding process. By setting a fixed time interval to trigger the camera to take pictures, the tab area can be avoided, but it is not possible to determine that the picture taking position of each coil of the battery at the winding material station and the picture taking position of the winding station can remain consistent, which reduces the reliability of the measured distance between the cathode and the anode of the battery (referred to as the cathode-anode distance).

[0006] SUMMARY

[0007] Therefore, the embodiments of the present disclosure at least provide an image acquisition method and system.

[0008] The technical scheme of the embodiments of the present disclosure is implemented as follows:

[0009] In one aspect, the present disclosure provides an image acquisition method, which comprises: receiving a first detection signal sent by a position sensor when the position sensor detects a tab on a winding material; obtaining a first pulse count emitted by an encoder arranged on a winding roller within a time between the first detection signal and a second detection signal; wherein the second detection signal is a detection signal adjacent in time to the first detection signal and sent by the position sensor; determining a total cumulative pulse number for triggering a camera to take pictures based on the first pulse count, a preset weight parameter and a first distance pulse number; wherein the weight parameter is used to represent the relative position information between the position of taking pictures of the winding material and the first tab in the winding coil where the current tab is located; and the first distance pulse number is used to represent the distance between the camera and the position sensor; and triggering the camera to take pictures of the winding material based on the total cumulative pulse number.

[0010] In the embodiments of the present disclosure, firstly, based on the first pulse count determined between the two adjacent tabs, the photographing position of the camera can be located between the two adjacent tabs, so as to avoid the tab area and photograph the coiled material; secondly, since the photographing position angle of the winding station is a fixed value, based on the weight parameters of the photographing position angle and the winding circle angle, the relative photographing position on the winding circle perimeter can be obtained, and then the photographing position of the coiled material station corresponding to the photographing position of the winding station can be obtained, so as to solve the misalignment problem of the photographing position of the winding station and the photographing position of the coiled material station. Further, there is one winding circle between the first detection signal and the second detection signal, and by counting the first pulse count emitted by the encoder between different winding circles, the coiled material can be photographed adaptively at different winding speeds, so as to eliminate the influence of the winding speed on the accuracy of the photographing position.

[0011] In some embodiments, the first pulse count emitted by the encoder arranged on the unwinding roller within the time between the first detection signal and the second detection signal includes: determining the first pulse sequence number emitted by the encoder at the time when the first detection signal is emitted; obtaining the second pulse sequence number emitted by the encoder at the time when the second detection signal is emitted; determining the pulse number between the first pulse sequence number and the second pulse sequence number as the first pulse count.

[0012] In the above embodiments, in the process of emitting the pulse signal by the encoder, the image controller sequentially counts the received pulse signal, so that the first pulse sequence number corresponding to the first detection signal and the second pulse sequence number corresponding to the second detection signal can be obtained, and then the first pulse count can be determined through the first pulse sequence number and the second pulse sequence number, so as to determine the total number of accumulated pulses according to the first pulse count determined based on the first pulse sequence number and the second pulse sequence number.

[0013] In some embodiments, the method further includes: establishing a mapping relationship between the first detection signal and the first pulse sequence number, and storing the mapping relationship in a storage area in the image acquisition system of the unwinding station.

[0014] In the above embodiments, the mapping relationship between the detection signal and the corresponding pulse sequence number is established, and the mapping relationship is stored in the corresponding storage area, so that after the first detection signal is received, the second pulse sequence number corresponding to the second detection signal can be obtained from the storage area.

[0015] In some embodiments, based on the first pulse count, the preset weight parameter, and the first distance pulse number, determining the total number of accumulated pulses for triggering the camera to take a picture comprises: taking the product of the first pulse count and the weight parameter as a second pulse count; the second pulse count is the pulse number corresponding to the distance from the next picture position of the camera to the first tab in the current winding circle; taking the difference between the second pulse count and the first pulse count as a third pulse count; wherein the third pulse count is the pulse number corresponding to the distance from the next picture position of the camera to the next tab; and taking the sum of the first distance pulse number and the third pulse count as the total number of accumulated pulses for triggering the camera to take a picture.

[0016] In the above embodiment, the product of the first pulse count and the weight parameter is taken as the second pulse count, which can obtain the pulse number corresponding to the distance from the next picture position of the camera to the current tab. Then, the difference between the second pulse count and the first pulse count is taken as the third pulse count, which can obtain the pulse number corresponding to the distance from the next picture position of the camera to the next tab. Finally, the sum of the first distance pulse number and the third pulse count is determined as the total number of accumulated pulses, so as to trigger the camera to take a picture of the material based on the total number of accumulated pulses.

[0017] In some embodiments, the method further comprises: based on the first pulse count emitted by the encoder, the circumference of the unwinding roller, and the second distance pulse number, determining the tab span between the adjacent two tabs in the to-be-generated battery cell; wherein the second distance pulse number is the number of pulse signals generated by the encoder when the unwinding roller rotates one revolution; and the tab span is used to control the camera to take a picture of the to-be-generated battery cell.

[0018] In the above embodiment, the ratio of the first pulse count and the second distance pulse number between the adjacent two tabs can determine the number of revolutions of the unwinding roller in one winding circle. By multiplying the number of revolutions of the unwinding roller and the circumference of the unwinding roller, the tab span between the adjacent two tabs in the to-be-generated battery cell can be determined. In the process of analyzing the collected image, the tab span is associated with the image collected by the camera to determine the picture position of the image collected by the camera on the material, and thus the analysis of the material can be realized.

[0019] In some embodiments, the first distance pulse number is greater than S times the first pulse threshold, the first pulse threshold is the pulse number corresponding to the tab span between the first tab and the adjacent next tab, and S is a real number greater than 1.

[0020] In the above embodiment, the first distance pulse number is set to be greater than S times the pulse number corresponding to the tab span between the first tab and the adjacent next tab, which is used to increase the total number of accumulated pulses for controlling the camera, so as to avoid the influence of the reaction time of the camera after receiving the picture signal. Thus, the image corresponding to the picture position of the winding station can be collected by the camera under different winding speeds.

[0021] In some embodiments, the method further comprises: obtaining a photographing position angle of the camera at the winding station; wherein the winding station is arranged after the unwinding station in the transmission direction of the winding material; and determining the quotient of the photographing position angle and the circumferential angle as the weight parameter.

[0022] In the above embodiments, the quotient of the photographing position angle of the camera at the winding station and the circumferential angle is determined as the weight parameter, so that the total number of cumulative pulses triggering the camera to take a picture of the winding material can be obtained based on the weight parameter, thereby achieving the consistency of the photographing position of the image at the unwinding station and the photographing position of the image at the winding station, and improving the reliability of the distance measurement between the cathode and the anode of the battery cell.

[0023] In some embodiments, in the case that the battery cell to be generated is a single-turn multi-tab type, the second detection signal is a detection signal corresponding to the number of tabs sent by the arrival sensor.

[0024] In the above embodiments, in the case that the battery cell to be generated is a single-turn multi-tab type, the second detection signal is a detection signal corresponding to the number of tabs sent by the arrival sensor, so that in the case that the battery cell is a single-turn multi-tab type, the number of photographing times at the unwinding station is consistent with the number of photographing times at the winding station.

[0025] On the other hand, the embodiments of the present disclosure provide an image acquisition system applied to an unwinding station, which comprises an encoder, an arrival sensor, a camera and an image acquisition controller; wherein,

[0026] The encoder is configured to emit a pulse signal when the unwinding roller moves;

[0027] The arrival sensor is configured to send a first detection signal to the image acquisition controller when detecting a tab on the winding material;

[0028] The camera is configured to take a picture of the winding material after receiving a photographing signal sent by the image acquisition controller;

[0029] The arrival sensor is configured to send a first detection signal to the image acquisition controller when detecting a tab on the winding material;The image acquisition controller is configured to receive a first detection signal sent by the in-position sensor when the in-position sensor detects the tab on the roll material; obtain a first pulse count of a first pulse emitted by the encoder arranged on the unwinding roller within a time interval between the first detection signal and a second detection signal sent by the in-position sensor; the second detection signal is a detection signal adjacent in time to the first detection signal; determine a total cumulative pulse number for triggering the camera to take a picture based on the first pulse count, a preset weight parameter, and a first distance pulse number; the weight parameter is used to represent relative position information between a position of taking a picture of the roll material and a first tab in a winding turn in which the current tab is located; the first distance pulse number is used to represent a distance between the camera and the in-position sensor; and trigger the camera to take a picture of the roll material based on the total cumulative pulse number.

[0030] In some embodiments, the image acquisition controller is further configured to determine a first pulse sequence number of the first pulse emitted by the encoder when the first detection signal is sent; obtain a second pulse sequence number of a second pulse emitted by the encoder when the second detection signal is sent; and determine a pulse number between the first pulse sequence number and the second pulse sequence number as the first pulse count.

[0031] In some embodiments, the image acquisition controller is further configured to take a product between the first pulse count and the weight parameter as a second pulse count; the second pulse count is a pulse number corresponding to a next picture position of the camera from the first tab in the winding turn in which the current tab is located; take a difference between the second pulse count and the first pulse count as a third pulse count; the third pulse count is a pulse number corresponding to the next picture position of the in-position sensor; and determine a sum of the first distance pulse number and the third pulse count as the total cumulative pulse number for triggering the camera to take a picture.

[0032] In some embodiments, the image acquisition controller is further configured to determine a tab span between two adjacent tabs in the to-be-generated battery cell based on the first pulse count of the first pulse emitted by the encoder, a circumference of the unwinding roller, and a second distance pulse number; the second distance pulse number is a number of pulse signals generated by the encoder when the unwinding roller rotates one round; and the tab span is used to control the camera to take a picture of the to-be-generated battery cell.

[0033] In some embodiments, the image acquisition controller is further configured to obtain a picture position angle of the camera at the winding station; the winding station is arranged after the unwinding station along a transmission direction of the roll material; and determine a quotient of the picture position angle and a circumferential angle as the weight parameter.

[0034] It should be understood that the above general description and the following detailed description are only exemplary and explanatory, but not limiting the technical solutions of the present disclosure. BRIEF DESCRIPTION OF DRAWINGS

[0035] The drawings incorporated into the specification and forming a part of the specification, illustrate embodiments consistent with the present disclosure and serve to explain the technical solutions of the present disclosure together with the specification.

[0036] Fig. 1 is a schematic diagram of a photographing position of a pay-off station of a related technology according to an embodiment of the present disclosure;

[0037] Fig. 2 is a schematic diagram of an image acquisition system of a pay-off station according to an embodiment of the present disclosure;

[0038] Fig. 3A is a schematic diagram of an implementation flow of an image acquisition method according to an embodiment of the present disclosure;

[0039] Fig. 3B is a schematic diagram of photographing positions of a pay-off station and a winding station according to an embodiment of the present disclosure;

[0040] Fig. 4A is a schematic diagram of an implementation flow of an image acquisition method of a single-circle multi-tab according to an embodiment of the present disclosure;

[0041] Fig. 4B is a schematic diagram of a single-circle multi-tab according to an embodiment of the present disclosure;

[0042] Fig. 4C is a schematic diagram of photographing positions of a single-circle multi-tab according to an embodiment of the present disclosure;

[0043] Fig. 5 is a schematic diagram of an image acquisition system of a pay-off station with a PLC as an image acquisition controller according to an embodiment of the present disclosure. DETAILED DESCRIPTION

[0044] In order to make the purposes, technical solutions and advantages of the present disclosure clearer, the technical solutions of the present disclosure are further described in detail below with reference to the drawings and embodiments, and the described embodiments should not be regarded as limiting the present disclosure, and all other embodiments obtained by those skilled in the art without creative labor fall within the scope of protection of the present disclosure.

[0045] In the following description, “some embodiments” are related to a subset of all possible embodiments, but it can be understood that “some embodiments” can be the same subset or different subsets of all possible embodiments, and can be combined with each other without conflict.

[0046] It should be noted that the terms “first\second\third” involved in the embodiments of the present disclosure are only to distinguish similar objects, and do not represent a specific order of the objects, and it can be understood that the “first\second\third” can be interchanged with a specific order or sequence as allowed, so that the embodiments of the present disclosure described herein can be implemented in an order other than that illustrated or described herein.

[0047] Those skilled in the art can understand that, unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art to which the embodiments of the present disclosure belong. It should also be understood that terms such as those defined in commonly used dictionaries should be interpreted as having a meaning that is consistent with their meaning in the context of the relevant art and will not be interpreted in an idealized or overly formal sense unless specifically so defined herein.

[0048] At present, power batteries are increasingly widely used in life and industry. Power batteries are not only applied to energy storage power supply systems such as hydroelectric, thermal, wind and solar power stations, but also widely used in electric bicycles, electric motorcycles, electric vehicles and other electric vehicles, and aerospace and other fields. With the continuous expansion of the application field of power batteries, the market demand is also increasing.

[0049] In the embodiments of the present disclosure, the power battery can be an electric core (also sometimes referred to as a battery monomer), and the battery can also be a battery module or a battery pack including a plurality of electric cores. The electric core refers to a basic unit capable of realizing mutual conversion between chemical energy and electrical energy, and can be used to make a battery module or a battery pack to supply power to a power consumption device. The electric core can be a secondary battery, which refers to an electric core that can be activated by charging after discharging, such as a lithium ion battery, a sodium ion battery, a sodium-lithium ion battery, a lithium metal battery, a sodium metal battery, a lithium-sulfur battery, a magnesium ion battery, a nickel-hydrogen battery, a nickel-cadmium battery, a lead-acid battery, etc. The embodiments of the present disclosure are not limited thereto.

[0050] In the production process of power batteries, the front and back surfaces of the film coating area need to be visually detected, including detecting the misregistration amount of the film coating area, detecting the distance between the cathode and the anode of the electric core, etc. Generally, a linear array or area array camera is used to collect images. However, the winding speed of the winding equipment is non-uniform during the winding process from winding to winding. By using a sensor to detect the tab and setting a fixed time interval to trigger the camera to take pictures, the tab area can be avoided, but it cannot be determined that the photographing position of each circle of the electric core to be generated at the unwinding station and the photographing position of the winding station can remain consistent, resulting in misregistration between the photographing position of the unwinding station and the photographing position of the winding station, and thus the reliability of the measured distance between the cathode and the anode of the electric core is reduced.

[0051] The misalignment of the fixed distance of the unwinding station photographing position and the photographing position of the winding station is illustrated by FIG. 1. As shown in FIG. 1, it is a schematic diagram of the photographing position of the unwinding station of the current to-be-produced battery cell, including the first tab, tab 2 and tab 3. One winding turn is between the first tab and tab 2. After the sensor detects the tab, the camera is controlled to take two pictures. The photographing position of the camera is determined by setting the fixed distance L1 and the fixed distance L2 of each winding turn from the previous tab at the unwinding station. Taking the winding turn between the first tab and tab 2 as an example, after the first tab is detected and the pulse counter accumulates the pulse number corresponding to the fixed distance L1 and the fixed distance L2 respectively, a control signal is sent to the camera to trigger the camera to take a picture. The photographing positions of the corresponding camera at the current winding turn are A” position and B” position. The photographing position of the winding station is determined by a fixed angle. Since the circumferences of different winding turns are inconsistent, the fixed angle of each winding turn of the winding station corresponds to different photographing positions. The photographing position of the unwinding station is achieved by a fixed distance. The photographing position of each winding turn of the unwinding station is consistent. Therefore, the photographing position of the unwinding station is misaligned with the photographing position of the winding station.

[0052] In related technologies, the image collection of the target area is achieved by installing a photoelectric sensor in the winding equipment and configuring the internal parameters of the camera. When the photoelectric sensor detects the tab, an impulse signal is output to control the industrial camera to take two pictures. The two pictures are separated by a fixed time interval ΔT. The target area can be automatically avoided, the industrial camera can be controlled to take pictures, and the shooting detection of the target area can be realized. However, the scheme has the following problems:

[0053] 1) The fixed photographing interval is set to control the camera to take two pictures between two tabs. However, since the winding process is a non-uniform motion, the scheme cannot adapt to different winding speeds.

[0054] 2) Different shooting positions cannot be set according to the distance between different tabs. Therefore, it cannot be applied to the detection of the misalignment amount of the coating area when the shape of the tab is convex and multiple tabs form a winding turn of the battery cell.

[0055] 3) cannot set the corresponding shooting position according to different winding turns, because the current cell has different per-layer circumferences, resulting in a certain misalignment between the detection position of the unwinding station and the detection position of the winding station (the winding station triggers the camera to take a picture by setting a fixed angle of rotation of the winding needle), and as the winding thickness of the to-be-generated cell increases, the misalignment between the detection position of the unwinding station and the detection position of the winding station gradually increases, so that in the case of taking the distance between the cathode and the anode measured by the human being as the reference, the distance between the cathode and the anode obtained by the camera is evaluated, resulting in a low evaluation pass rate of the distance between the cathode and the anode obtained by the camera, and further, in the case of a low evaluation pass rate, the reliability of the distance between the cathode and the anode of the cell determined by the camera is reduced.

[0056] Next, the installation diagram of part of the equipment of the image acquisition system of the unwinding station is introduced, as shown in FIG. 2, the image acquisition system includes a reach sensor 1, an encoder 2, a camera 3, a winding material 4, an unwinding roller 5 and a fixed roller 6, wherein a bracket 11 is installed on the unwinding roller 5, and the reach sensor 1 is installed on the bracket 11, used to identify the tab when the tab passes through the pulse signal emitted by the reach sensor 1, the encoder 2 is installed on the unwinding roller 5 to emit a pulse signal when the unwinding roller 5 moves, and the camera 3 is used to take a picture of the winding material 4 after receiving a shooting signal.

[0057] In some embodiments, the reach sensor 1 is installed at a position where the tab can be detected to pass, so that the pulse signal emitted by the reach sensor can detect the tab when the tab passes through the pulse signal, wherein the reach sensor 1 can be a through-type sensor or a reflective sensor.

[0058] In some embodiments, the reach sensor 1 can be a through-type sensor, when the tab passes through the detection position of the sensor, the tab will block the pulse signal emitted by the transmitter in the through-type sensor, and the receiver in the through-type sensor will not receive the corresponding pulse signal, so as to determine that the tab passes through the detection position.

[0059] In some embodiments, the reach sensor 1 can be a reflective sensor, when the tab passes through the detection position of the sensor, the tab will reflect the pulse signal emitted by the reflective sensor back to the reflective sensor, and the reflective sensor will receive the reflected pulse signal, so as to determine that the tab passes through the detection position.

[0060] The embodiment of the present disclosure provides an image acquisition method, as shown in FIG. 3, which can include steps S301 to S304:

[0061] Step S301: receiving a first detection signal when the reach sensor detects the tab on the winding material;

[0062] Here, the image acquisition method is applied to an image acquisition controller of a unwinding station, where the image acquisition controller can be a PLC (Programmable Logic Controller) or a vision host computer; the unwinding station refers to unwinding raw materials (such as pole pieces, diaphragms, etc.) at a certain speed and accuracy for subsequent processes such as coating, winding or lamination. The in-place sensor refers to a sensor for detecting whether an object has reached a target position and outputting a signal. The tab is a metal conductor that leads the positive and negative electrodes out of the battery cell.

[0063] In some embodiments, when the in-place sensor determines that the detection position has a tab passing through, the in-place sensor sends a first detection signal to the image acquisition controller of the unwinding station, and the first detection signal is used to indicate that a tab is detected.

[0064] Step S302: obtaining the first pulse count emitted by the encoder arranged on the unwinding roller within the time between the first detection signal and the second detection signal;

[0065] Wherein, the second detection signal is a detection signal adjacent in time to the first detection signal sent by the in-place sensor;

[0066] Here, the encoder is a sensor device that converts physical signals (such as rotation angle, linear displacement, etc.) into electrical signals (such as pulse, encoding, etc.). The second detection signal is a detection signal adjacent to the first detection signal, where the second detection signal can be a detection signal before the first detection signal or a detection signal after the first detection signal. The first pulse count refers to the number of pulse signals emitted by the encoder between the first detection signal and the second detection signal sent by the in-place sensor.

[0067] It should be noted that the detection signals adjacent in time are relative to the number of tabs in a winding circle formed by the winding device, and the number of tabs in a winding circle can include single-tab single-circle and multi-tab single-circle.

[0068] Wherein, single-tab single-circle refers to that two adjacent tabs can form a winding circle, for example, the distance between tab 1 and tab 2 is a winding circle, and the distance between tab 2 and tab 3 is a winding circle, so it can be said that the detection signal of tab 1 and the detection signal of tab 2 are adjacent, and the detection signal of tab 2 and the detection signal of tab 3 are adjacent.

[0069] The multiple tabs of the single winding and multiple tabs can form a winding circle. The multiple tabs can be understood as more than 2 tabs, for example, 2 tabs, 3 tabs, 4 tabs. When the number of tabs is 2, the distance between tab 1 and tab 3 is a winding circle, and the distance between tab 3 and tab 5 is a winding circle. It can be said that the detection signal of tab 1 and the detection signal of tab 3 are adjacent, and the detection signal of tab 3 and the detection signal of tab 5 are adjacent.

[0070] In some embodiments, the image acquisition controller timestamps the first detection signal as a first timestamp and timestamps the second detection signal as a second timestamp, and determines the number of pulse signals emitted by the encoder between the first timestamp and the second timestamp.

[0071] In some embodiments, for a single winding and a single tab, in the case that the second detection signal is a detection signal before the first detection signal, first, in the case that the first detection signal is received, a storage area in the image acquisition controller that stores detection signals is searched, and it is determined whether the storage area stores a detection signal. In the case that it is determined that the storage area stores a detection signal, the detection signal stored at the previous time can be obtained, and the obtained detection signal is taken as the second detection signal.

[0072] In some embodiments, for a single winding and a single tab, in the case that the second detection signal is a detection signal after the first detection signal, first, in the case that the first detection signal is received, a storage area in the image acquisition controller that stores detection signals is searched, and it is determined whether the storage area stores a detection signal. In the case that it is determined that the storage area does not store a detection signal, the detection signal sent by the position sensor after detecting the tab again is waited for, and the received detection signal is taken as the second detection signal.

[0073] In some embodiments, for a single winding and multiple tabs, in the case that the second detection signal is a detection signal before the first detection signal, first, in the case that the first detection signal is received, a storage area in the image acquisition controller that stores detection signals is searched, and it is determined whether the storage area stores a detection signal. In the case that it is determined that the storage area stores a detection signal, the detection signal stored at the time before the number of corresponding tabs is obtained, and the obtained detection signal is taken as the second detection signal.

[0074] For example, the number of tabs is 2, in the case that the first detection signal is received, the detection signals of the previous 2 times of the corresponding storage area are searched, for example, the first detection signal is in the storage area corresponding to the pulse order 5, and the second detection signal should be in the storage area corresponding to the pulse order 3. Therefore, the detection signal of the pulse order 3 is the second detection signal.

[0075] In some embodiments, the single winding multi-tab is described, and in the case that the second detection signal is a detection signal after the first detection signal, first, in the case that the first detection signal is received, the storage area in the image acquisition controller where the detection signal is stored is searched, it is determined whether the detection signal is stored in the storage area, in the case that it is determined that the detection signal is not stored, the detection signal sent after the position sensor detects the corresponding tab number again is waited for, and the received detection signal is taken as the second detection signal.

[0076] For example, the tab number is 2, in the case that the first detection signal is received, the detection signal after the position sensor receives 2 tabs is waited for, for example, the pulse sequence number corresponding to the first detection signal in the storage area is 7, and the pulse sequence number corresponding to the received second detection signal in the storage area should be 9, so the detection signal with the pulse sequence number 9 is the second detection signal.

[0077] Step S303: determining the total number of accumulated pulses for triggering the camera to take a picture based on the first pulse count, the preset weight parameter and the first distance pulse number;

[0078] Wherein, the weight parameter is used to represent the relative position information between the position of taking a picture of the coiled material and the first tab in the winding circle where the current tab is located; and the first distance pulse number is used to represent the distance between the camera and the position sensor.

[0079] Here, the weight parameter is determined relative to the picture angle of the camera of the winding station.

[0080] In some embodiments, the distance between the camera and the position sensor can be obtained first, and then the obtained distance is converted into a corresponding pulse number.

[0081] In implementation, first, the distance between the camera and the position sensor is obtained, then the distance between the camera and the position sensor is divided by the circumference of the unwinding roller to obtain a value, which is determined as the distance weight value, and finally, the distance weight value is multiplied by the second distance pulse number to obtain a value, which is determined as the first distance pulse number.

[0082] It should be noted that based on the weight parameter, the distance between the position of taking a picture of the coiled material and the first tab in the winding circle where the current tab is located can be determined. Wherein, the first tab in the winding circle can be understood as the first tab in the process of forming the winding circle, for example, the distance between the tab 1 and the tab 2 is one winding circle, and the first tab is the tab 1; the distance between the tab 1 and the tab 3 is one winding circle, and the first tab is the tab 1.

[0083] Step S304: triggering the camera to take a picture of the coiled material based on the total number of accumulated pulses.

[0084] Here, the camera selected is a plane array camera, because the plane array camera is a camera that can acquire images at one time and collect images in time, and it can collect images in units of planes, and has the advantage of intuitive measurement of images.

[0085] In some embodiments, a photographing signal is sent to the camera when the total number of pulses accumulated by the pulse counter is equal to the total number of accumulated pulses, and the camera receives the photographing signal and photographs the web.

[0086] In the embodiments of the present disclosure, first, based on the first pulse count determined between the two adjacent tabs, the photographing position of the camera can be located between the two adjacent tabs, so that the tabs can be avoided to photograph the web; second, since the photographing position angle of the winding station is a fixed value, based on the weight parameters of the photographing position angle and the winding circle angle, the relative photographing position on the winding circle circumference can be obtained, and then the photographing position of the web station corresponding to the photographing position of the winding station can be obtained, which can solve the misalignment problem of the photographing position of the winding station and the photographing position of the unwinding station. Further, there is one winding circle between the first detection signal and the second detection signal, and by counting the first pulse count emitted by the encoder between different winding circles, the web can be photographed adaptively at different winding speeds, so as to eliminate the influence of the winding speed on the accuracy of the photographing position.

[0087] In some embodiments, the first pulse count emitted by the encoder arranged on the unwinding roller within the time between the first detection signal and the second detection signal in the above step S302 can include steps S3021 to S3023:

[0088] Step S3021: determining the first pulse sequence number emitted by the encoder at the time when the first detection signal is emitted;

[0089] In some embodiments, the image acquisition controller numbers and stores each pulse signal emitted by the encoder in sequence.

[0090] In some embodiments, after the first detection signal is acquired, the image acquisition controller reads the storage area of the pulse sequence number of the encoder, determines the pulse sequence number corresponding to the pulse signal emitted by the encoder at the time when the first detection signal is emitted, and takes the acquired pulse sequence number as the first pulse sequence number.

[0091] Step S3022: acquiring the second pulse sequence number emitted by the encoder at the time when the second detection signal is emitted;

[0092] Here, the second pulse number can be a pulse number smaller than the first pulse number, or a pulse number larger than the first pulse number. The second pulse number is smaller than the first pulse number because the second detection signal emitted by the position sensor is a detection signal before the first detection signal. The second pulse number is larger than the first pulse number because the second detection signal emitted by the position sensor is a detection signal after the first detection signal.

[0093] In some embodiments, after the second detection signal is acquired, the image acquisition controller timestamps the second detection signal, reads the storage area of the pulse number of the encoder, determines the pulse number corresponding to the pulse signal emitted by the encoder at the time when the second detection signal is emitted, and takes the acquired pulse number as the second pulse number.

[0094] Step S3023: Determine the number of pulses between the first pulse number and the second pulse number as the first pulse count.

[0095] In some embodiments, the first pulse count can be obtained by first calculating the first difference between the first pulse number and the second pulse number, and then adding 1 to the difference.

[0096] For example, the first pulse number is 1256 and the second pulse number is 1600. The number of pulses between the first pulse number and the second pulse number is 345.

[0097] In the above embodiments, the image controller sequentially counts the received pulse signals in the process of the encoder emitting pulse signals, so that the first pulse number corresponding to the first detection signal and the second pulse number corresponding to the second detection signal can be acquired. Then, the first pulse count can be determined through the first pulse number and the second pulse number, so that the total number of cumulative pulses can be determined based on the first pulse count determined based on the first pulse number and the second pulse number.

[0098] In some embodiments, the above step S302 further includes: establishing a mapping relationship between the first detection signal and the first pulse number, and storing the mapping relationship in a storage area in the image acquisition controller of the unwinding station.

[0099] In some embodiments, the mapping relationship between the first detection signal and the first pulse number can be established in the form of a key-value pair. Here, the first detection signal can be taken as the key in the key-value pair, and the first pulse number can be taken as the value in the key-value pair.

[0100] In some embodiments, after receiving the detection signal emitted by the position sensor when detecting the tab, the pulse number of the detection signal is determined, and then the detection signal and the corresponding pulse number are sequentially stored in the storage area in the image acquisition controller in the form of a key-value pair.

[0101] In some embodiments, the mapping relationship between the first detection signal and the first pulse number can be stored in a data table in the image acquisition controller, or can be stored in a buffer area in the image acquisition controller.

[0102] In the above embodiments, the mapping relationship between the detection signal and the corresponding pulse number is established, and the mapping relationship is stored in the corresponding storage area. In this way, after receiving the first detection signal, the second pulse number corresponding to the second detection signal can be obtained from the storage area.

[0103] In some embodiments, the step S303 of determining the total number of accumulated pulses for triggering the camera to take a picture based on the first pulse count, the preset weight parameter, and the first distance pulse number can include steps S3030-S3032:

[0104] Step S3030: multiplying the product between the first pulse count and the weight parameter as the second pulse count; the second pulse count is the pulse number corresponding to the first polar ear in the current winding circle from the next shooting position of the camera to the current polar ear;

[0105] Here, the product of the first pulse count and the weight parameter can be an integer or a decimal.

[0106] In some embodiments, in the case of an integer product, the product is determined as the second pulse count; in the case of a decimal product, the product needs to be first processed by rounding, and the processed product is determined as the second pulse count, wherein the rounding processing can round the product, or can remove the decimal places in the product, or can add 1 to the integer places in the product and then remove the decimal places.

[0107] In some embodiments, the distance between the next shooting position of the camera and the current polar ear can be determined by the second pulse count.

[0108] Step S3031: taking the difference between the second pulse count and the first pulse count as the third pulse count;

[0109] Wherein, the third pulse count is the pulse number corresponding to the next shooting position of the position sensor;

[0110] In some embodiments, the distance between the next shooting position and the position sensor can be determined by the third pulse count.

[0111] Step S3032: determining the sum of the first distance pulse number and the third pulse count as the total number of accumulated pulses for triggering the camera to take a picture.

[0112] In some embodiments, the shooting position of the camera on the web material can be determined by the total number of accumulated pulses.

[0113] In the above embodiment, the product of the first pulse count and the weight parameter is taken as the second pulse count, the distance of the next photographing position of the camera from the current corresponding pulse number of the tab is obtained, then the difference between the second pulse count and the first pulse count is taken as the third pulse count, the pulse number of the next photographing position of the in-position sensor from the camera is obtained, and finally the sum of the first distance pulse number and the third pulse count is determined as the total number of accumulated pulses, so as to trigger the camera to take a photograph of the coiled material based on the total number of accumulated pulses.

[0114] In some embodiments, the image acquisition method further comprises step S305:

[0115] Step S305: determining the tab span between the two adjacent tabs in the to-be-generated battery cell based on the first pulse count emitted by the encoder, the circumference of the unwinding roller, and the second distance pulse number.

[0116] The second distance pulse number is the number of pulse signals generated by the encoder when the unwinding roller rotates one round, and the tab span is used to control the camera to take a photograph of the to-be-generated battery cell.

[0117] Here, the tab span can be the distance between the two adjacent tabs on the same side corresponding to the number of winding turns. For single-turn single-tab, the tab span can be the distance between tab 1 and tab 2, or the distance between tab 3 and tab 4. For single-turn multi-tab, when the number of tabs is 2, the tab span can be the distance between tab 1 and tab 3, or the distance between tab 3 and tab 5.

[0118] In some embodiments, the diameter of the unwinding roller can be obtained first, and then the circumference of the unwinding roller can be calculated. For example, the diameter of the unwinding roller is φ, and the circumference of the unwinding roller is πφ.

[0119] In some embodiments, the product of the first pulse count, the circumference of the unwinding roller, and the second distance pulse number can be obtained.

[0120] In some embodiments, the counting of the pulse signals emitted by the encoder can be started when the unwinding roller starts to rotate, and the counting of the pulse signals emitted by the encoder can be stopped when the unwinding roller stops rotating. The final count value is determined as the second distance pulse number.

[0121] In some embodiments, the time when the unwinding roller starts to rotate is taken as the third time stamp, and the third pulse number of the pulse signal of the encoder at the third time stamp is determined. The time when the unwinding roller stops rotating is taken as the fourth time stamp, and the fourth pulse number of the pulse signal at the fourth time stamp is determined. The second difference between the fourth pulse number and the third pulse number is determined, and then the difference value plus 1 is the second distance pulse number.

[0122] In some embodiments, the photographing position of the camera on the coiled material is determined based on the tab span, the length of the direction of the camera from the to-position sensor to the walking belt, and the angle of the photographing position of the camera of the winding station.

[0123] In the above embodiment, the number of rotations of the unwinding roller in one winding circle can be determined by the ratio of the first pulse count and the second distance pulse count between the two adjacent tabs, and the tab span between the two adjacent tabs in the to-be-generated battery cell is determined by multiplying the number of rotations of the unwinding roller by the circumference of the unwinding roller. In the process of analyzing the collected image, the tab span is associated with the collected image of the camera to determine the photographing position of the collected image of the camera on the coiled material, and then the coiled material can be analyzed.

[0124] In some embodiments, the first distance pulse count is greater than S times the first pulse count threshold, the first pulse count threshold is the pulse count corresponding to the tab span between the first tab and the adjacent tab, S is a real number greater than 1, and the first distance pulse count is an integer.

[0125] Here, the first tab refers to the first tab of the to-be-produced battery cell. S is a real number greater than 1, for example, S is 1.33, S is 2, or S is 4.

[0126] In some embodiments, when S is a decimal number, S times the first pulse count threshold can be a decimal number or an integer. When S times the first pulse count threshold is a decimal number, it needs to be rounded, which can be rounded to the nearest integer, or the decimal places of S times the first pulse count threshold can be removed, or the integer places of S times the first pulse count threshold can be increased by 1 and then the decimal places can be removed.

[0127] It should be noted that the tab span between the first tab and the adjacent next tab refers to the innermost circle of the to-be-generated battery cell in the process of winding the film material by the winding device. The adjacent next tab is relative to the number of tabs in a winding circle formed by the winding device.

[0128] For example, for single-circle single-tab, the distance between tab 1 (i.e., the first tab) and tab 2 is one winding circle, and the distance between tab 2 and tab 3 is one winding circle. It can be said that tab 2 is the adjacent next tab of tab 1, and tab 3 is the adjacent next tab of tab 2.

[0129] For single-circle multi-tab, for example, the number of tabs is 2, the distance between tab 1 and tab 3 is one winding circle, and the distance between tab 3 and tab 5 is one winding circle. It can be said that tab 3 is the adjacent next tab of tab 1, and tab 5 is the adjacent next tab of tab 3.

[0130] In some embodiments, the first tab in the adjacent tabs corresponding to the tab span can be determined as the first tab when the tab span is compared with the preset inner ring length and the tab span is equal to the inner ring length.

[0131] In the above embodiment, the first distance pulse number is set to be greater than the pulse number corresponding to the tab span between the first tab and the next tab, which is used to increase the cumulative pulse number for controlling the camera, so as to avoid the influence of the reaction time of the camera after receiving the shooting signal, thereby realizing the triggering of the image corresponding to the shooting position of the winding station under different winding speeds.

[0132] In some embodiments, the method for determining the weight parameter in step S303 can include step S3033 and step S3034:

[0133] Step S3033: obtaining a shooting position angle of the camera at the winding station; wherein the winding station is arranged after the unwinding station along the transmission direction of the winding material;

[0134] Here, the winding station refers to a position where the winding material is wound into various rolls according to certain rules in the process production, for example, in the production of battery cells, the winding station can realize the winding of the positive tab, the separator and the negative tab according to a certain order by fixing the winding needle, and extruding into a cylindrical, elliptical cylindrical or square shape. The shooting position angle is the angle value of the winding circle corresponding to the shooting position determined in the winding station, wherein one circle of the winding circle is 360 degrees, so the angle value to be selected is less than 360 degrees, for example, 30 degrees, 270 degrees.

[0135] In some embodiments, the shooting position of the winding station is determined by the shooting position angle, which can first determine the position of the winding needle at 0 degree, and then send a control signal to the camera when the winding needle rotates to the shooting position angle, triggering the camera to shoot.

[0136] It should be noted that the shooting of the camera at the unwinding station is prior to the shooting of the camera at the winding station because the process of the winding station is performed after the process of the unwinding station is completed.

[0137] Step S3034: determining the quotient of the shooting position angle and the circumferential angle as the weight parameter.

[0138] Here, the circumferential angle refers to the angle formed by a ray rotating one circle around its endpoint, and the angle is equal to 360 degrees.

[0139] It should be noted that the weight parameter is determined relative to the photographing position angle of the camera of the winding station, and the photographing position of the unwinding station corresponding to the photographing position of the winding station can be determined through the weight parameter, so as to solve the misalignment problem between the photographing position of the camera of the unwinding station and the photographing position of the camera of the winding station.

[0140] As shown in FIG. 3B, the photographing positions of the unwinding station 12 and the winding station 13 are illustrated, wherein the winding station 13 comprises a winding device 131; the unwinding station 12 comprises a camera 3, a coiled material 4, an unwinding roller 5 and a fixed roller 6. Here, the photographing positions of the unwinding station 12 and the winding station 13 are illustrated with the first pole to the pole 3 as one winding turn, and the photographing position angle θ A The determined photographing position is photographing position A, and the photographing position angle θ B The determined photographing position is photographing position B, and the photographing position angle θ A and the photographing position angle θ B The corresponding interval angle is θ A -θ B In order to solve the misalignment problem between the photographing position of the camera of the unwinding station 12 and the photographing position of the camera of the winding station, the photographing position angle θ A and the photographing position angle θ B are obtained to calculate the weight parameter of the total number of accumulated pulses. Then, the photographing position A' and the photographing position B' of the unwinding station are obtained through the photographing position angle θ A and the photographing position angle θ B corresponding weight parameters, respectively, wherein the photographing position A of the winding station corresponds to the photographing position A' of the unwinding station, and the photographing position B of the winding station corresponds to the photographing position B' of the unwinding station.

[0141] In some embodiments, the distance between the positive and negative poles at the corresponding position of the unwinding station can be measured manually to obtain a manual detection value. Then, the distance between the positive and negative poles is determined through the images collected by the camera of the winding station and the camera of the unwinding station to obtain a camera detection value. Finally, the manual detection value and the camera detection value are compared. Taking the manual detection value as the reference, it is determined whether the camera detection value is accurate. In implementation, the difference between the manual detection value and the camera detection value is calculated. When the calculated difference is within a preset range, it is determined that the camera detection value is qualified, otherwise it is determined that the camera detection value has a problem.

[0142] In some embodiments, the method for obtaining the camera detection value can be as follows: first, the first distance between the film coating area and the anode is obtained from the image captured by the camera at the winding station, and the second distance between the film coating area and the cathode is obtained from the image captured by the camera at the unwinding station; then, the difference between the first distance and the second distance is determined as the distance between the anode and the cathode, and the distance between the anode and the cathode obtained is determined as the camera detection value.

[0143] It should be noted that if the photographing position at the winding station and the photographing position at the unwinding station are inconsistent, the first distance between the film coating area and the anode obtained from the winding station and the second distance between the film coating area and the cathode obtained from the unwinding station correspond to different positions of the winding coil, so that the camera detection value calculated based on the first distance and the second distance at different positions is unreliable.

[0144] In the above embodiment, the quotient of the photographing angle of the camera at the winding station and the circumferential angle is determined as the weight parameter, so that the total number of accumulated pulses triggering the camera to take a picture of the coil material can be obtained based on the weight parameter, thereby realizing that the photographing position of the image at the unwinding station is consistent with the photographing position of the image at the winding station, and improving the reliability of the distance measurement between the cathode and the anode of the battery cell.

[0145] In some embodiments, when the battery cell to be generated is a single-coil multi-tab type, the second detection signal is a detection signal corresponding to the number of tabs sent by the in-place sensor.

[0146] Here, when the number of tabs is 2, the distance between tab 1 and tab 3 is one winding coil, and the distance between tab 3 and tab 5 is one winding coil. Correspondingly, when the first detection signal is emitted when tab 1 is detected, the second detection signal can be emitted when tab 3 is detected; when the first detection signal is emitted when tab 3 is detected, the second detection signal can be emitted when tab 5 is detected.

[0147] It should be noted that when the battery cell to be generated is a single-coil single-tab type, the distance between tab 1 and tab 2 is one winding coil, and the winding station takes two pictures per coil. To keep the number of photographs at the unwinding station consistent with the number of photographs at the winding station, tab 1 and tab 2 can be set to take two pictures; when the battery cell is a single-coil multi-tab type, if the number of tabs is 2, the distance between tab 1 and tab 3 is one winding coil, and the winding station takes two pictures per coil. To keep the number of photographs at the unwinding station consistent with the number of photographs at the winding station, it is necessary to determine that tab 1 and tab 3 take two pictures, so it is necessary to filter out tab 2 to prevent tab 1 and tab 2 from taking two pictures and tab 2 and tab 3 from taking two pictures.

[0148] In the above embodiment, when the to-be-generated battery cell is of the single-turn multi-tab type, the second detection signal is a detection signal corresponding to the number of tabs of the first detection signal sent by the in-place sensor, so that when the battery cell is of the single-turn multi-tab type, the number of photographing times of the unwinding station is consistent with the number of photographing times of the winding station.

[0149] The above image acquisition method will be described below in combination with an embodiment. In order to facilitate understanding, taking single-turn multi-tab as an example, a possible process suitable for the embodiments of the present disclosure is introduced. However, it should be noted that the embodiment is only used to better illustrate the present disclosure and does not constitute an improper limitation on the present disclosure.

[0150] As shown in FIG. 4A, an image acquisition method for single-turn multi-tab is provided, which can include steps S401 to S403:

[0151] Step S401: configuring related parameters;

[0152] Here, the related parameters can include the diameter of the follow-up roller the number of pulses n0 generated by the encoder when the follow-up roller rotates one turn, the length L0 of the photoelectric sensor from the camera in the running direction, the angle θ corresponding to the photographing position A of the winding station camera A and the angle θ corresponding to the photographing position B of the winding station camera B .

[0153] Therefore, based on the above parameters, the winding length formula of the coiled material can be obtained:

[0154] wherein, is the diameter of the follow-up roller on which the encoder is installed, n is the number of pulses of the encoder, and n0 is the number of pulses generated by the encoder when the follow-up roller rotates one turn.

[0155] Step S402: determining the first tab of the current battery cell and the photographing position A' and the photographing position B' of the unwinding station camera of each winding turn according to the configured parameters;

[0156] In the process of producing the battery cell, as the coiled material is wound by the winding device, the number of winding turns gradually increases, and the winding length of each winding turn also increases synchronously. The first tab is the first tab of the to-be-generated battery cell and is located in the innermost layer of the winding layer. As described above, the winding turn corresponding to the first tab is the innermost turn of the to-be-generated battery cell, and thus the winding length thereof is the smallest. Therefore, only the innermost turn needs to be determined, and the first tab in the innermost turn is the first tab.

[0157] In implementation, first, a single winding of a coating material is performed, then the number of pulses sent by the encoder between adjacent odd two pulse signals of the photosensor is obtained, the ear span between adjacent odd ears is calculated by formula (1), and compared with the preset inner ring length. In the case that the ear span is equal to the inner ring length, the first ear of the current to-be-generated battery cell can be determined.

[0158] It should be noted that most of the battery cells on the market are single-coil single-ear, and the winding length of the winding coil refers to the distance between adjacent two ears, which can also be referred to as ear span, and the embodiment of the present disclosure is illustrated by taking single-coil multi-ear as an example. As shown in FIG. 4B, a schematic diagram of the ear position on the winding material is shown, including the tab area 21 and the AT area 22. Here, the first ear to the third ear is taken as a winding coil for illustration, since the winding coil includes the first ear, the second ear and the third ear, when calculating the winding length of the winding coil, the even ear, i.e. the second ear, needs to be filtered out, and the distance between adjacent odd ears is regarded as a winding coil, i.e. L1 is a winding coil length.

[0159] After determining the first ear of the current to-be-generated battery cell, it is also necessary to confirm the shooting position A ’ and the shooting position B ’ of the unwinding station camera of each winding coil.

[0160] In implementation, first, the PLC determines the total number N of pulse signals emitted by the encoder between adjacent odd pulse signals of the photosensor every time the adjacent odd two pulse signals of the photosensor are received, then the winding length between adjacent odd ears is calculated by formula (1):

[0161] The length of the shooting position A of the winding station in the current winding coil can be obtained by formula (2) and the angle θ A corresponding to the shooting position A of the winding station camera, i.e. the length between the shooting position of the camera and the first ear of the current winding coil:

[0162] L n* θ A / 2π (3);

[0163] Further, the length of the photosensor from the camera in the running direction is added to L0, the length between the shooting position of the camera and the first ear of the current winding coil is added, and the winding length between the adjacent odd ears that have passed is subtracted, so as to obtain the shooting position A ’ of the unwinding station camera.

[0164] Corresponding to the shooting position A of the winding station camera, the shooting position A' of the unwinding station camera is:

[0165] L0+L n *(θ A / 2π-1) (4);

[0166] Similarly, corresponding to the winding station camera shooting position B, the unwinding station camera shooting position B' is:

[0167] L0+L n *(θ B / 2π-1) (5);

[0168] As shown in FIG. 4C, the tab is a special-shaped boss structure shape in the shaded part, and the distance L1 between the first tab and the tab 3 is one winding circle. Taking the first tab as an example, the width of the coating area corresponding to the tab area and the coating area corresponding to the non-tab area are different. Generally, the width of the tab area is 30-40 mm. In the process of image acquisition of the coating area in the battery production process, the accuracy of camera shooting is required to be high, and the field of view range of the corresponding camera will be reduced. Generally, the field of view range of the camera is 20-30 mm. It can be seen that the tab area is larger relative to the field of view range of the camera. If the tab area is not avoided, the photos taken by the camera may all be the tab area. There is a difference between the tab area and the tab area inside the tab area. If the tab area is not avoided, the displacement detection of the coating area will be affected. Taking the first tab to the tab 3 as one winding circle, it can be seen from the shooting position A' and the shooting position B' of the unwinding station determined by formula (3) and formula (4) in this winding circle that the tab area is avoided.

[0169] Step S403: According to the set parameters, the device normally winds, takes two pictures for each circle of the battery cell, and analyzes the collected images.

[0170] As can be seen from the above step S402, the shooting position of the unwinding station is determined based on the shooting angle of the winding position. Therefore, the shooting position of the unwinding station camera determined by formula (3) and formula (4) is relatively consistent with the shooting position of the winding station.

[0171] Here, the camera of the unwinding station collects images at the shooting position of the unwinding station determined by formula (4) or formula (5), and the camera of the winding station collects images at the shooting position of the winding station determined by formula (3).

[0172] The first distance between the coating film area and the anode can be measured by the picture collected by the camera of the winding station, and the second distance between the coating film area and the cathode can be measured by the picture collected by the camera of the unwinding station, and then the distance between the anode and the cathode is determined by the difference between the first distance and the second distance.

[0173] Further, the distance between the anode and the cathode determined by the collected image is compared with the distance between the anode and the cathode measured by manual measurement, and whether the distance between the anode and the cathode determined by the collected image is accurate is determined based on the value measured by manual measurement.

[0174] In implementation, the difference between the manual detection value and the camera detection value can be determined first, and if the difference is within a preset range, it is determined that the camera detection value is normal, otherwise the camera detection value is abnormal. The distance between the anode and the cathode determined by the collected image is the camera detection value, and the distance between the anode and the cathode measured by manual measurement is simply referred to as the manual detection value.

[0175] It should be noted that the in-place sensors in the foregoing embodiments can be implemented as the photoelectric sensors described above; and the unwinding roller can be implemented as the follow-up roller described above.

[0176] In the embodiments of the present disclosure, an image collection method is provided, which can recognize the tab through a photoelectric sensor. The winding length is automatically calculated according to the signal fed back by the encoder, which can adapt to different winding speeds, realize image collection and size detection at a specified position avoiding the tab area, accurately position the size defect area, and improve the reliability of OH (the distance between the cathode and the anode of the battery cell) detection. The following beneficial effects can be obtained based on the embodiments of the present disclosure:

[0177] 1) The influence of the winding speed on image collection can be eliminated, and the photographing interval is automatically adjusted, so that the photographing position of the unwinding station corresponds to the photographing position of the winding station, image collection and target size detection at a specified film area position avoiding the tab area are realized, and the reliability of OH measurement is improved.

[0178] 2) The odd / even tab of the single-turn multi-tab coating film material can be screened, and the current battery cell single-turn is photographed twice to match the photographing times of the winding position camera.

[0179] The embodiments of the present disclosure take PLC as an example for illustration, as shown in FIG. 5, the image collection system applied to the unwinding station includes an encoder 2, an in-place sensor 1, a camera 3 and a PLC 7; wherein,

[0180] The encoder 2 is used to emit a pulse signal when the unwinding roller moves;

[0181] Here, the encoder sends a pulse signal to the PLC when the unwinding roller moves.

[0182] The in-place sensor 1 is configured to send a first detection signal to the PLC when detecting the tab on the roll material.

[0183] Here, the in-place sensor detects the tab on the roll material by continuously sending a pulse signal to the roll material.

[0184] The camera 3 is configured to take a photo of the roll material after receiving a photo signal sent by the PLC.

[0185] Here, the camera sends the collected image to the industrial computer after taking a photo of the roll material.

[0186] The PLC 7 is configured to receive a first detection signal sent by the in-place sensor when detecting the tab on the roll material; obtain a first pulse count emitted by an encoder arranged on the unwinding roller within a time between the first detection signal and a second detection signal sent by the in-place sensor; the second detection signal is a detection signal adjacent in time to the first detection signal; determine a total number of cumulative pulses for triggering the camera to take a photo based on the first pulse count, a preset weight parameter, and a first distance pulse number; the weight parameter is used to represent relative position information between a position of taking a photo of the roll material and a first tab in a winding circle where the current tab is located; the first distance pulse number is used to represent a distance between the camera and the in-place sensor; and trigger the camera to take a photo of the roll material based on the total number of cumulative pulses.

[0187] In some embodiments, the PLC 7 is further configured to determine a first pulse sequence number emitted by the encoder when the first detection signal is sent; obtain a second pulse sequence number emitted by the encoder when the second detection signal is sent; and determine a pulse number between the first pulse sequence number and the second pulse sequence number as the first pulse count.

[0188] In some embodiments, the PLC 7 is further configured to multiply the first pulse count by the weight parameter as a second pulse count; the second pulse count is a pulse number corresponding to a next photo position of the camera from the first tab in the winding circle where the current tab is located; determine a difference between the second pulse count and the first pulse count as a third pulse count; the third pulse count is a pulse number corresponding to the next photo position of the in-place sensor; and determine a sum of the first distance pulse number and the third pulse count as the total number of cumulative pulses for triggering the camera to take a photo.

[0189] In some embodiments, the PLC 7 is further configured to determine a tab span between two adjacent tabs in the to-be-generated battery cell based on the first pulse count emitted by the encoder, a circumference of the unwinding roller, and a second distance pulse number; the second distance pulse number is a number of pulse signals generated by the encoder when the unwinding roller rotates one revolution; and the tab span is used to control the camera to take a photo of the to-be-generated battery cell.

[0190] In some embodiments, the image acquisition system applied to the unwinding station further comprises an industrial computer 8 and a central control display 9, wherein,

[0191] The industrial computer 8, as a visual host computer, is an image processing terminal, and has a core computing model thereon for analyzing the images collected by the camera 3.

[0192] Here, the industrial computer 8 sends the analysis result to the central control display 9.

[0193] The central control display 9 is configured to display the processing result output by the industrial computer 8.

[0194] It should be noted that the above description of various embodiments tends to emphasize the differences between the various embodiments, and the same or similar parts can be referred to each other. The above description of the device, storage medium, computer program and computer program product embodiments is similar to the description of the method embodiments, and has similar beneficial effects as the method embodiments. For technical details not disclosed in the device, storage medium, computer program and computer program product embodiments of the present disclosure, please refer to the description of the method embodiments of the present disclosure.

[0195] It should be understood that the "one embodiment" or "an embodiment" mentioned throughout the specification means that the specific features, structures or characteristics related to the embodiment are included in at least one embodiment of the present disclosure. Therefore, "in one embodiment" or "in an embodiment" appearing throughout the specification does not necessarily refer to the same embodiment. In addition, these specific features, structures or characteristics can be combined in one or more embodiments in any suitable manner. It should be understood that in various embodiments of the present disclosure, the size of the serial number of each step / process does not mean the execution order, and the execution order of each step / process should be determined by its function and inherent logic, and should not constitute any limitation on the implementation process of the embodiments of the present disclosure. The above serial numbers of the embodiments of the present disclosure are only for description, not representing the advantages or disadvantages of the embodiments.

[0196] It should be noted that in this document, the term "comprising" or "including" or any other variant thereof is intended to cover non-exclusive inclusion, so that the process, method, article or device including a series of elements not only includes those elements, but also includes other elements not explicitly listed or inherent to such process, method, article or device. Without more limitations, the element defined by the statement "including a" does not exclude the presence of another identical element in the process, method, article or device including the element.

[0197] In several embodiments provided by the present disclosure, it should be understood that the disclosed devices and methods can be implemented in other manners. The embodiments described above are merely exemplary, and are not intended to limit the application. For example, the division of the units is merely logical function division, and there can be other division manners in actual implementation. For example, a plurality of units or components can be combined or integrated into another system, or some features can be ignored or not executed. In addition, the coupling or direct coupling or communication connection between the components shown or discussed can be indirect coupling or communication connection through some interfaces, devices or units, and can be electrical, mechanical or in other forms.

[0198] The units described as separate components can or can not be physically separate, and the components shown as units can or can not be physical units; they can be located in one place or distributed on a plurality of network units; and some or all of the units can be selected according to actual needs to achieve the purpose of the embodiments.

[0199] In addition, each functional unit in each embodiment of the present disclosure can be integrated into one processing unit, or each unit can be a separate unit, or two or more units can be integrated into one unit; and the integrated unit can be implemented in the form of hardware or hardware plus software functional units.

[0200] Those of ordinary skill in the art can understand that all or part of the steps of the above-mentioned method embodiments can be completed by a program instructing related hardware, and the aforementioned program can be stored in a computer readable storage medium, and when the program is executed, the steps of the method embodiments are executed; and the aforementioned storage medium includes mobile storage devices, read-only memories (ROM), magnetic discs or optical discs, and various storage media that can store program codes.

[0201] Alternatively, the integrated units of the present disclosure, if implemented in the form of software functional modules and sold or used as independent products, can also be stored in a computer readable storage medium. Based on this understanding, the technical solutions of the present disclosure can be embodied in the form of a software product, and the computer software product is stored in a storage medium, and includes a plurality of instructions for causing a computer device (which can be a personal computer, a server, or a network device, etc.) to execute all or part of the embodiments of the methods of the present disclosure. The aforementioned storage medium includes mobile storage devices, ROM, magnetic discs or optical discs, and various storage media that can store program codes.

[0202] The above merely describes the embodiments of the present disclosure, but the protection scope of the present disclosure is not limited thereto, and any person skilled in the art can easily think of changes or replacements within the technical range disclosed by the present disclosure, which should be covered within the protection scope of the present disclosure.

Claims

1. An image acquisition method, the method comprising: receiving a first detection signal sent by a position sensor in a case where the position sensor detects a tab on a roll material; acquiring a first pulse count of a first pulse emitted by an encoder arranged on a pay-off roll within a time between the first detection signal and a second detection signal, wherein the second detection signal is a detection signal adjacent in time to the first detection signal and sent by the position sensor; determining a total cumulative pulse number for triggering a camera to take a picture based on the first pulse count, a preset weight parameter, and a first distance pulse number; wherein the weight parameter is used to represent relative position information between a position at which the roll material is taken a picture and a first tab in a winding turn in which a current tab is located, and the first distance pulse number is used to represent a distance between the camera and the position sensor; triggering the camera to take a picture of the roll material based on the total cumulative pulse number.

2. The method as claimed in claim 1, wherein, The acquiring of the first pulse count of the first pulse emitted by the encoder arranged on the pay-off roll within the time between the first detection signal and the second detection signal comprises: determining a first pulse sequence number of the first pulse emitted by the encoder at the time when the first detection signal is sent; acquiring a second pulse sequence number of the second pulse emitted by the encoder at the time when the second detection signal is sent; determining a pulse number between the first pulse sequence number and the second pulse sequence number as the first pulse count.

3. The method as recited in claim 2, wherein, The method further comprises: establishing a mapping relationship between the first detection signal and the first pulse sequence number, and storing the mapping relationship in a storage area in an image acquisition system of a pay-off station.

4. The method according to any one of claims 1 to 3, wherein, The determining of the total cumulative pulse number for triggering the camera to take a picture based on the first pulse count, the preset weight parameter, and the first distance pulse number comprises: multiplying a product between the first pulse count and the weight parameter as a second pulse count, wherein the second pulse count is a pulse number corresponding to a next picture position of the camera from a first tab in a winding turn in which a current tab is located; determining a difference between the second pulse count and the first pulse count as a third pulse count, wherein the third pulse count is a pulse number corresponding to a distance between the position sensor and the next picture position; determining a sum between the first distance pulse number and the third pulse count as the total cumulative pulse number for triggering the camera to take a picture.

5. The method according to any one of claims 1 to 4, wherein, The method further comprises: determining a tab span between two adjacent tabs in a to-be-generated battery cell based on the first pulse count emitted by the encoder, a circumference of the pay-off roll, and a second distance pulse number; wherein the second distance pulse number is a number of pulse signals generated by the encoder in a case where the pay-off roll rotates one round, and the tab span is used to control the camera to take a picture of the to-be-generated battery cell.

6. The method according to any one of claims 1 to 5, wherein, The first distance pulse number is greater than S times a first pulse number threshold, the first pulse number threshold is a pulse number corresponding to a tab span between a first tab and a next adjacent tab, and S is a real number greater than 1.

7. The method according to any one of claims 1 to 6, wherein, The method further comprises: acquiring a picture position angle of a camera at a winding station, wherein the winding station is arranged after the pay-off station in a transmission direction of the roll material. The quotient of the photographing position angle and the circumferential angle is determined as the weight parameter.

8. The method according to any one of claims 1 to 7, wherein, In a case where the to-be-generated battery cell is a single-circle multi-tab type, the second detection signal is a detection signal corresponding to a number of tabs of the first detection signal sent by the in-place sensor. 9.An image acquisition system applied to a unwinding station, the image acquisition system comprising an encoder, an in-place sensor, a camera and an image acquisition controller; wherein, the encoder is configured to emit a pulse signal when the unwinding roller moves; the in-place sensor is configured to send a first detection signal to the image acquisition controller when detecting a tab on the coiled material; the camera is configured to take a photograph of the coiled material after receiving a photographing signal sent by the image acquisition controller; the image acquisition controller is configured to receive the first detection signal sent by the in-place sensor when detecting a tab on the coiled material; acquire a first pulse count emitted by the encoder arranged on the unwinding roller within a time between the first detection signal and a second detection signal; wherein the second detection signal is a detection signal adjacent in time to the first detection signal sent by the in-place sensor; determine a total cumulative pulse number for triggering the camera to take a photograph based on the first pulse count, a preset weight parameter and a first distance pulse number; wherein the weight parameter is used to represent relative position information between a position at which the coiled material is photographed and a first tab in a winding circle in which the current tab is located; the first distance pulse number is used to represent a distance between the camera and the in-place sensor; and trigger the camera to take a photograph of the coiled material based on the total cumulative pulse number. 10.The image acquisition system applied to a unwinding station according to claim 9, wherein, the image acquisition controller is further configured to determine a first pulse sequence number emitted by the encoder at the time when the first detection signal is sent; acquire a second pulse sequence number emitted by the encoder at the time when the second detection signal is sent; and determine a pulse number between the first pulse sequence number and the second pulse sequence number as the first pulse count. 11.The image acquisition system applied to a unwinding station according to claim 10, wherein, the image acquisition controller is further configured to establish a mapping relationship between the first detection signal and the first pulse sequence number, and store the mapping relationship in a storage area in the image acquisition system of the unwinding station. 12.The image acquisition system applied to a unwinding station according to any one of claims 9 to 11, wherein, the image acquisition controller is further configured to take a product between the first pulse count and the weight parameter as a second pulse count; the second pulse count is a pulse number corresponding to a next photographing position of the camera from the first tab in the winding circle in which the current tab is located; a difference between the second pulse count and the first pulse count is taken as a third pulse count; wherein the third pulse count is a pulse number corresponding to the next photographing position of the in-place sensor; and a sum of the first distance pulse number and the third pulse count is determined as the total cumulative pulse number for triggering the camera to take a photograph. ​ 13. The image acquisition system applied to the unwinding station according to any one of claims 9 to 12, wherein, the image acquisition controller is further configured to determine, based on the first pulse count, the circumference of the unwinding roller, and a second distance pulse number, a tab span between two adjacent tabs in the to-be-generated battery cell; the second distance pulse number is a number of pulse signals generated by the encoder when the unwinding roller rotates one round; and the tab span is used to control the camera to take a picture of the to-be-generated battery cell.

14. The image acquisition system for use in a spooling station according to any one of claims 9 to 13, wherein, The first distance pulse number is greater than S times a first pulse threshold, the first pulse threshold is a pulse number corresponding to the tab span between the first tab and the next adjacent tab, and S is a real number greater than 1.

15. The image acquisition system applied to the unwinding station according to any one of claims 9 to 14, wherein, the image acquisition controller is further configured to obtain a photographing position angle of the camera at the winding station; the winding station is arranged after the unwinding station along a transmission direction of the winding material; and a quotient of the photographing position angle and the circumferential angle is determined as the weight parameter.

16. The image acquisition system for use in a spooling station according to any one of claims 9 to 15, wherein, In a case where the to-be-generated battery cell is a single-coil multi-tab type, the second detection signal is a detection signal corresponding to a number of tabs of the first detection signal and sent by the in-place sensor.

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