Since the beginning of modern industrial robots in the early 1980s, robots have been guided by machine vision. Originally there were only a few robots with vision, but today it is over 5,000 robots annually in the North American market and significantly more globally. Vision guided robotics (VGR) are robotic application where cameras are used to find the location features on a workpiece and provide the location of that workpiece to the robot so that it can interact with it. Robots interact with the workpiece in many ways, the very common way is for a VGR robot to find and pick a part. Using vision to locate the workpiece allows for flexibility in the way the parts are presented to the robot, often loosening the requirements for expensive fixtures that otherwise position the workpiece in a repeatable location for the robot. VGR is one of the largest growing sectors in both the robotics and machine vision market.
To properly guide a robot based on an image from a camera two things must happen. First the desired target must be found in the image, this is called vision processing. Second, the location of the found target in the image must be provided to the robot in a way that it can use, this is done through calibration. Camera calibration defines the location of the camera with respect to the robot as well as the millimeter to pixel scale of the image. The vision processing tools locate the part in pixel space and the calibration is used to convert its location into millimeter space relative to coordinates that are defined in the robot.