Deviation detection method and deviation detection device

A deviation detection method for detecting positional deviation of an electrode assembly during a winding process of the electrode assembly, the electrode assembly comprising a first electrode sheet and a second electrode sheet, wherein the deviation detection method comprises:

• an image obtaining step of obtaining a plurality of first images and a plurality of second images by a photographing unit during the winding process of the electrode assembly, the plurality of the first images comprising the first electrode sheet, and the plurality of the second images comprising the second electrode sheet,
• an image matching step of matching a first image from the plurality of first images with a second image from the plurality of second images, the first image and the second image containing the same or corresponding identification objects, the identification objects being portions periodically formed on each winding layer of the electrode assembly, and
• a deviation determining step of determining whether the electrode assembly is deviated in a pair of the matching first and second images according to a boundary of the first electrode sheet in the matching first image and/or a boundary of the second electrode sheet in the matching second image,
• wherein the identification objects are a tab of the first electrode sheet and/or a tab of the second electrode sheet in the same winding layer.