US Patent 10078908 Determination of relative positions

A workcell has a camera module with two optical systems and a memory containing information about the arrangement of the optical systems, a robot module with a first coordinate system, a first set of fiducials, and a memory containing information about the 3D positions of the first set of fiducials defined within the first coordinate system, and a fixture with a second coordinate system, a second set of fiducials, and a memory containing information about the 3D positions of the second set of fiducials defined within the second coordinate system. A processor is communicatively coupled to the camera module, the robot module, and the fixture. The processor is configured to receive information about positions of each of the fiducials as observed by the two optical systems, retrieve from the various memories information about the arrangement of the first and second optical systems, the 3D positions of the first set of fiducials, and the 3D positions of the second set of fiducials, and determine the position and orientation of the fixture in the coordinate system of the robot module.