Method utilizing image correlation to determine position measurements in a machine vision system

A precision machine vision inspection system comprising a stage that receives a workpiece, an imaging system that images the workpiece, a scale-based measurement portion that provides position measurements indicative of the stage position relative to the imaging system, a control system, a display, and a user interface wherein:

• the machine vision inspection system is configured to provide first and second operating states used to provide position measurements, wherein,
• the first operating state comprises determining the position of an image based on a scale-based position measurement provided by the scale-based measurement portion;
• the second operating state comprises providing the position of at least one second-state image based on enhanced second-state position measurement provided by using image correlation, the enhanced second-state position measurement comprising:
• referencing a first image captured at a first image position, the first image position characterized by a first position measurement;
• moving from the first image position toward a second-state image position used to capture the second-state image and capturing overlapping images between the first image position and the second-state image position;
• capturing the second-state image at the second-state image position;
• and
• providing the enhanced second-state position measurement based on the first position measurement and a set of image displacements determined based on using image correlation applied to the first image, the overlapping images, and the second-state image, and
• the user interface is displayed on the display at least during a learn mode of operation of the machine vision inspection system, and the user interface comprises a second-state indicator that indicates when the second operating state that provides the enhanced second-state position measurement is active.