Vision inspection systems and methods for laser welds
A vision inspection system for laser welds includes a scanning station to support a workpiece including one or more laser welds. A vision sensing assembly includes a top surface, a bottom surface, side surfaces, a light source, and a sensor. The light source illuminates the workpiece while the sensor generates an image of the one or more laser welds of the workpiece. A shield is arranged around the top surface and the side surfaces of the vision sensing assembly. The bottom surface of the vision sensing assembly is arranged above a lower edge of the shield by a first predetermined distance.
1 . A vision inspection system for laser welds, comprising:
a scanning station to support a workpiece including one or more laser welds;
a vision sensing assembly positioned relative to the scanning station and including a top surface, a bottom surface, side surfaces extending between the top surface and the bottom surface, a light source, and a sensor,
wherein the light source illuminates a region of interest of the workpiece coinciding with the one or more laser welds while the sensor generates an M images of the region of interest coinciding with the one or more laser welds of the workpiece, wherein each image of the M images are generated using M different exposure periods where the M different exposure periods each correspond with differing lengths of time such that each image of the M images captures information at a specific depth or a surface of specific reflectivity according to the M different exposure periods, where M is an integer greater than one; and
a shield arranged around the top surface and the side surfaces of the vision sensing assembly,
wherein the bottom surface of the vision sensing assembly is arranged above a lower edge of the shield by a first predetermined distance such that the shield covers a buffer zone around the top surface, the bottom surface, and the side surfaces of the vision sensing assembly to protect the vision sensing assembly from light pollution, dust, and/or impact.
2 . The vision inspection system of claim 1 , wherein the first predetermined distance is greater than or equal to 2 inches.
3 . The vision inspection system of claim 1 , further comprising a repairing station adjacent to the scanning station and configured to support a repair workpiece requiring repairs, wherein the repairing station is located below the scanning station by a second predetermined distance such that the repair workpiece is disposed below the workpiece supported with the scanning station.
4 . The vision inspection system of claim 3 , wherein the second predetermined distance is greater than or equal to 1 inch.
5 . The vision inspection system of claim 1 , further comprising a robot including an end effector to deliver the workpiece to the scanning station.
6 . The vision inspection system of claim 5 , wherein the robot is held stationary for a predetermined period prior to generating the image.
7 . The vision inspection system of claim 1 , further comprising a mount supporting the vision sensing assembly, wherein the mount is made of a material selected from a group consisting of aluminum and copper.
8 . The vision inspection system of claim 1 , further comprising a light shield including an aperture arranged between the light source and the workpiece to block an undesired light area and provide reduced dimensions of projected light around the one or more laser welds of the workpiece.
9 . The vision inspection system of claim 8 , wherein reduced dimensions of the projected light define a predetermined buffer zone around a zone including normal production variations in a location of the one or more laser welds.
10 . The vision inspection system of claim 9 , wherein the predetermined buffer zone is greater than or equal to 10 mm.
11 . The vision inspection system of claim 1 , further comprising a controller including an image processing module configured to combine the M images of the one or more laser welds into a composite image, wherein the image processing module is configured to analyze the composite image to determine whether a morphology of the one or more laser welds meets a predetermined criteria.
12 . A method for inspecting laser welds, comprising:
using a scanning station to support a workpiece including one or more laser welds;
arranging a vision sensing assembly including a top surface, a bottom surface, side surfaces, a light source, and a sensor above the workpiece;
arranging a shield around the top surface and the side surfaces of the vision sensing assembly,
wherein the bottom surface of the vision sensing assembly is arranged above a lower edge of the shield by a first predetermined distance;
illuminating the workpiece while the sensor generates M images of the one or more laser welds of the workpiece from one field of view of the sensor and using M different exposure periods where the M different exposure periods each correspond with differing lengths of time such that each image of the M images captures information at specific depths or surface of specific reflectivity according to the M different exposure periods, where M is an integer greater than one; and
combining the M images into a composite image.
13 . The method of claim 12 , further comprising locating a repairing station, configured to support a workpiece requiring repairs, below the scanning station by a second predetermined distance, wherein the second predetermined distance is greater than or equal to 1 inch.
14 . The method of claim 12 , further comprising delivering the workpiece to the scanning station using a robot including an end effector, wherein the robot is held stationary for a predetermined period prior to generating the M images.
15 . The method of claim 12 , further comprising using a mount to support the vision sensing assembly, wherein the mount is made of a material selected from a group consisting of aluminum and copper.
16 . The method of claim 12 , further comprising arranging a light shield including an aperture between the light source and the workpiece to reduce dimensions of light projected around the one or more laser welds of the workpiece, wherein the reduced dimensions of the projected light define a predetermined buffer zone around a zone including normal production variations in a location of the one or more laser welds.
17 . A vision inspection system for laser welds, comprising:
a scanning station configured to support a workpiece including one or more laser welds, wherein the one or more laser welds are configured to respectively join two or more components;
a vision sensing assembly configured to visually inspect the one or more laser welds after being welded, wherein the vision sensing assembly includes a top surface, a bottom surface, side surfaces, a light source, and a sensor,
wherein the light source illuminates the workpiece while the sensor generates a plurality of images of the one or more laser welds relative to one field of view the sensor, wherein the sensor generates each image of the plurality of images using a different exposure periods where the different exposure periods each correspond with differing lengths of time such that each image of the plurality of images captures information at specific depths or surface of specific reflectivity according to the different exposure period,
a controller including an image processing module configured to combine the plurality of images into a composite image and analyze the composite image to determine whether a morphology of the one or more laser welds meets a predetermined criteria; and
a shield arranged around the top surface and the side surfaces of the vision sensing assembly,
wherein the bottom surface of the vision sensing assembly is arranged above a lower edge of the shield by a first predetermined distance.
18 . The vision inspection system according to claim 17 , wherein:
the different exposure periods reduce or avoid use of data filling/filter functions and/or an inter-reflective function in software of the vision sensing assembly that causes artificial noise;
wherein one of the different exposure periods is 325 μs and one or more of the different exposure periods is greater than 325 μs; and
one side of the one field of view of the sensor is longer than another side of the one field of view to reduce or avoid shadowing in the composite image occurring relative to a concavity of the one or more laser welds.
19 . The vision inspection system of claim 11 , wherein:
the sensor includes a singular field of view, wherein one side of the singular field of view of the sensor is longer than another side of the singular field of view to reduce or avoid shadowing in the composite image occurring relative to a concavity of the one or more laser welds;
wherein one of the M different exposure periods is 325 μs and one or more of the M different exposure periods is greater than 325 μs; and
each image of the M images is taken relative to the singular field of view.
20 . The method of claim 12 , further comprising analyzing the composite image to determine whether a morphology of the one or more laser welds meets a predetermined criteria, wherein the different exposure periods reduce or avoid use of data filling/filter functions and/or an inter-reflective function in software of the vision sensing assembly that cause artificial noise, wherein one side of the one field of view of the sensor is longer than another side of the one field of view to reduce or avoid shadowing in the composite image occurring relative to a concavity of the one or more laser welds, wherein one of the M different exposure periods is 325 μs and one or more of the M different exposure periods is greater than 325 μs.