Visual identification positioning system and method based on preorder guidance and image gray scale matching

The invention relates to the technical field of visual detection, in particular to a visual recognition positioning system and method based on preorder guidance and image gray matching, when an image of a to-be-detected piece is detected, whether a preorder detection result exists in the system or not is judged, and if the preorder detection result exists, the system is started; taking the position of the preorder detection result as the reference of a local matching area, and carrying out NCC-based image matching visual positioning in the local matching area; and if the preorder detection result does not exist, globally carrying out NCC-based image matching visual positioning on the image of the to-be-detected piece, taking a visual positioning detection result as a preorder detection result, and providing preorder guide information during next detection. According to the method, a large amount of invalid image gray information can be eliminated by using a preorder detection result, and relatively high posit