Battery cell exterior inspection system
A system for inspecting an exterior of a battery cell includes a tray on which battery cells are mounted in a plurality of rows, a first photographing part configured to horizontally move along the tray and photograph an upper surface of the battery cell while on the tray, at least one shuttle on which the battery cell is mounted, a transfer part configured to transfer the battery cells from the tray to the shuttle, a second photographing part configured to photograph a side surface and a lower surface of the battery cell while in the shuttle, and an inspection part configured to inspect a photographed image and determine whether the battery cell is defective. The second photographing part simultaneously photographs the side surface and the lower surface of the battery cell to simultaneously display the side and lower surfaces of the battery cell in one image.
1 . A system for inspecting battery cell exteriors, comprising:
a tray configured to hold a plurality of battery cells to be inspected in a plurality of rows, wherein the battery cells are arranged in a two dimensional array in the tray;
a first photographing part configured to horizontally move above the tray and photograph an exterior of an upper surface of the battery cells held in the tray;
at least one shuttle configured to hold a row of the battery cells, wherein the row of the battery cells is arranged as a one-dimensional array in the shuttle;
a transfer part that is structurally independent of the shuttle and configured to remove the row of the battery cells from the tray and deposit the battery cells in the shuttle;
a second photographing part configured to photograph exteriors of a side surface and a lower surface of the row of the battery cells held in the shuttle; and
an inspection part configured to inspect images photographed by the first and second photographing parts and determine whether the exterior of at least one battery cell of the plurality of battery cells is defective,
wherein the second photographing part is configured to photograph the side surface and the lower surface of the battery cell in a single image using a single camera, wherein the single camera includes a main lens facing the lower surface of the battery cells and a plurality of reflectors within a field of view of the main lens, wherein each reflector is positioned to face a respective portion of the side surface of the battery cell such that the single image visualizes each of the lower surface and the respective portions of the side surface of the battery cell.
2 . The system of claim 1 , wherein the first photographing part includes:
at least one first image camera;
at least one first lighting configured to emit light at different angles using a multi-channel method; and
a first controller configured to control operations of the first image camera and the first lighting.
3 . The system of claim 2 , wherein the first lighting includes coaxial lighting, dome lighting, and low-angle lighting.
4 . The system of claim 2 , wherein the first controller is configured to:
sequentially photograph the exteriors of the upper surfaces of the battery cells in an initial row of the tray while controlling the first image camera and the first lighting to move along the initial row of the tray;
after the initial row of the tray is photographed, horizontally move the tray to position a next row of the tray below the first photographing part;
sequentially photograph the exteriors of the upper surfaces of the battery cells in the next row of the tray while controlling the first image camera and the first lighting to move along the next row of the tray; and
repeat horizontally moving the tray and photographing the exteriors of the upper surfaces of the batteries of the next row of the tray until all rows of the tray are photographed.
5 . The system of claim 1 , further comprising an alignment jig configured to align central axes of the battery cells disposed in the shuttle and to form regular intervals between the battery cells in the shuttle, wherein the alignment jig is configured to increase a degree of alignment of the battery cells disposed in the shuttle as compared to the degree of alignment of the battery cells in the tray.
6 . The system of claim 5 , wherein the alignment jig comprises:
a pair of plate-shaped members positioned at opposing side surfaces of the battery cell; and
a plurality of grooves positioned at regular intervals on one side of the alignment jig and in contact with the battery cell, and configured to accommodate the battery cells.
7 . The system of claim 6 , wherein the row of the battery cells held in the shuttle extend along a primary axis, and wherein the plurality of grooves are formed by an undulating pattern in the pair of plates along a direction of the primary axis.
8 . The system of claim 1 , wherein the second photographing part includes:
one or more second image cameras including the single camera;
one or more second lightings configured to emit light towards the battery cells;
one or more extractors configured to extract the battery cells from the shuttle and transfer the battery cells to a photographing position; and
a second controller configured to control operations of the one or more second image cameras, the one or more second lighting, and the one or more extractors.
9 . The system of claim 8 , wherein the one or more extractors are configured to extract a row of battery cells from the shuttle and move the row of battery cells in a linear path such that each battery cell is sequentially positioned in the photographing position above the single camera.
10 . The system of claim 9 , wherein the second controller is configured to, for each battery cell of the row of battery cells:
detect the battery cell coming into the photographing position; and
in response to the detection, transmit a trigger signal to the single camera to capture the single image of the lower surface and respective portions of the side surface of the battery cell.
11 . The system of claim 8 , wherein the second photographing part includes:
an extractor configured to extract the row of battery cells having the aligned central axes from the shuttle; and
a second controller configured to control operations of the one or more second image cameras, the one or more second lighting, and the one or more extractors.
12 . The system of claim 11 , wherein the second photographing part includes a camera, and wherein the one or more extractors are configured to extract a row of battery cells from the shuttle and move the extracted row of battery cells in a linear path such that each battery cell is sequentially positioned in the photographing position above the camera.
13 . The system of claim 1 , wherein the inspection part is configured to:
detect at least one of a color, contrast, or chroma of at least one of the upper surface, the side surface or the lower surface of the at least one battery cell displayed on the images; and
determine whether a contamination event, a scratch, or a dent has occurred on the upper surface, the side surface or the lower surface of the at least one battery cell.
14 . The system of claim 1 , wherein the inspection part is configured to determine whether the exterior of the at least one battery cell of the plurality of battery cells is defective through deep learning.
15 . The system of claim 1 , wherein the inspection part includes:
a first inspection part configured to inspect images photographed by the first photographing part; and
a second inspection part configured to inspect images photographed by the second photographing part.
16 . The system of claim 15 , wherein the first inspection part is further configured to analyze a two-dimensional code attached to at least one of the upper surfaces, the side surfaces or the lower surfaces of the battery cells.
17 . The system of claim 15 , wherein the second computing device is configured to:
crop portions of the inspected images to derive cropped images;
distinguish side surface portions from lower surface portions of the battery cells in the cropped images; and
determine whether the exterior of at least one battery cell of the plurality of battery cells is defective based at least in part on an inspection of the distinguished side surface portion of the at least one battery cell and the distinguished lower surface portion of the at least one battery cell.
18 . The system of claim 1 , wherein the plurality of battery cells comprise button-type battery cells or cylindrical battery cells.
19 . The system of claim 1 , wherein the first photographing part comprises a plurality of first image cameras and a controller, wherein the plurality of first image cameras are positioned over respective rows of the tray and wherein each first image camera is configured to sequentially photograph the exteriors of the upper surfaces of the battery cells in its respective row of the tray while moving along the respective row of the tray.