US Patent 10956777 Shelf position calibration in a global coordinate system using a sensor array

An object tracking system includes a first sensor, a second sensor, and a tracking system. The tracking system is configured to determine that the first current pixel location for the shelf marker does not match a first expected pixel location for the shelf marker. The tracking system is further configured to determine a second current pixel location for the shelf marker within a second frame from the second sensor, to recalibrate the first sensor when the second current pixel location for the shelf marker matches the second pixel location for the shelf marker and to update the first pixel location with the first current pixel location and the second pixel location with the second current pixel location when the second current pixel location for the shelf marker does not match the second pixel location for the shelf marker.