Manufacturing processes that depend on visual inspection for quality control can often improve quality and reduce labor costs by using machine vision. Machine vision is generally better than human vision in inspection and control tasks that are fast, precise, and repetitive. A machine vision system also needs to control “hands” to move parts into its field of view, to sort parts, change process settings, or guide assembly.
Human vision is remarkably robust to changes in angle of view, changes in lighting, and can ignore minor variations in parts, for example the texture of a part’s finish. Machine vision is not as robust, and so requires parts to be placed within a known field of view and the part lighting needs to be carefully controlled. Machine vision is also less tolerant of part variations, which can be a benefit if these variations indicate defects. To its credit, a machine vision system can make hundreds of precise measures per second and, once installed, is cheap and reliable labor.