US Patent 7959353 Infra-red thermal imaging of laser welded battery module enclosure components

A thermal imaging system for a battery module enclosure that includes first and second battery module enclosure components between which a weld is formed includes a thermal imaging camera that focuses on the first and second battery module enclosure components within a predetermined amount of time after the weld is formed and that acquires a thermal signature. A control module includes an image processing module that receives the thermal signature and that locates a predetermined reference point in the thermal signature. An image comparison module receives the thermal signature and uses the predetermined reference point to compare the thermal signature to a template signature in order to verify structural integrity of the weld. The image comparison module computes a relative measure of deviation of the thermal signature from the template signature and identifies the weld as defective when the relative measure of deviation is greater than a predetermined value.