Patent Document ID: 9940535
Application ID: 15698316
Patent Status: 1

Claim One:
1. A method of sensor calibration relative to a common frame of reference having orthogonal depth, height and shift dimensions, by an imaging controller, the method comprising: obtaining, via a camera mounted on a mobile automation apparatus, an image of a calibration target associated with a location of the mobile automation apparatus in the common frame of reference; the calibration target including: a first surface at a first predefined depth bearing a first set of indicia at respective first heights and having respective first predefined shifts, each of the first indicia encoding the corresponding first height; and a second surface at a second predefined depth bearing a second set of indicia at respective second heights and having respective second predefined shifts, each of the second indicia encoding the corresponding second height; decoding, by the imaging controller, the first and second heights from the indicia of the first and second sets; generating, by the imaging controller, a first transform between an image frame of reference and a first plane at the first predefined depth in the common frame of reference, and a second transform between the image frame of reference and a second plane at the second predefined depth in the common frame of reference; applying, by the imaging controller, the first and second transforms to each of a plurality of calibration pixels selected from the image to generate, for each calibration pixel, a position pair including a first calibration position on the first plane and a second calibration position on the second plane; and determining, by the imaging controller, a camera position in the common frame of reference from an intersection of calibration lines defined by the position pairs.