Centering unit, centering system and centering method for sheets at line start of stamping line

A centering unit for sheets at line start of a stamping line, comprising vision cameras (5) and a controller which are electrically connected, and further comprising centering units for sheets at line start of a stamping line, each centering unit for sheets at line start of a stamping line comprising a base (10), wherein a support frame (6) is provided on each base (10), a static platform (1) is provided on each support frame (6), three adjustment assemblies are provided on each static platform (1), each adjustment assembly comprises a moving seat (14), each moving seat (14) can be linearly and movably arranged on the corresponding static platform (1), moving directions of the three moving seats (14) enclose a triangular structure, a connecting end (122) of a connecting rod (12) is rotationally connected to each moving seat (14), adjustment ends (121) of the three connecting rods (12) are all rotationally connected to the same movable platform (2), each movable platform (2) and the corresponding static platform (1) are arranged in parallel, and a conveying assembly (8) is provided on each movable platform (2);

• the vision cameras (5) are arranged on a support (7) and are arranged opposite the movable platforms (2), the controller comprises a storage module and a calculation module, the storage module stores a calculation method for a moving distance of the moving seats (14) corresponding to single-sheet feeding and dual-sheet feeding, and the calculation module is used for calculating the moving distance of the moving seats (14);
• two centering units for sheets at line start of a stamping line are arranged, the two entering units for sheets at line start of a stamping line are arrayed in a direction perpendicular to a sheet conveying direction, and two vision cameras (5) are arranged;
• the vision cameras (5) collect image information of sheets to be fed, and transmit the image information to the controller, the controller determines single-sheet feeding or dual-sheet feeding according to the image information, if the single-sheet feeding is determined, a coordinate system for the single-sheet feeding is called, and if the dual-sheet feeding is determined, a coordinate system for the dual-sheet feeding is called;
• the coordinate system for single-sheet feeding comprises a collaborative static coordinate system and a collaborative movable coordinate system, wherein an origin of the collaborative static coordinate system is a midpoint of a connecting line of centroids of triangles formed by the three adjustment assemblies on each of the two static platforms, an X-axis of the collaborative static coordinate system is a straight line in the moving direction of the moving seat of one of the adjustment assemblies, a Y-axis of the collaborative static coordinate system is a straight line perpendicular to the moving direction of the moving seat, and a Z-axis of the collaborative static coordinate system is a straight line perpendicular to the static platform;
• an origin of the collaborative movable coordinate system is a midpoint of a connecting line of centroids of triangles formed by the three adjustment assemblies on each of the two movable platforms, an X-axis of the collaborative movable coordinate system is a straight line where a connecting line of adjustment ends of the connecting rods of the other two adjustment assemblies is located, and a Z-axis of the collaborative movable coordinate system is a straight line perpendicular to the movable platform;
• and the coordinate system for dual-sheet feeding comprises two independent static coordinate systems and two independent movable coordinate systems, wherein origins of the two independent static coordinate systems are respectively the centroids of the triangles formed by the three adjustment assemblies on the corresponding static platforms, the X-axis, the Y-axis, and the Z-axis of the two independent static coordinate systems are parallel to the corresponding axes of the collaborative static coordinate system, origins of the two independent movable coordinate systems respectively use the centroids of the triangles formed by the three adjustment ends of the movable platform as a coordinate origin, and the X-axis, the Y-axis, and the Z-axis of the two independent movable coordinate systems are parallel to the corresponding axes of the collaborative movable coordinate system.