Using depth-camera images to speed registration of three-dimensional scans

A method for measuring and registering three-dimensional (3D) coordinates comprising:

• providing a 3D measuring device that includes a processor system, a 3D scanner, a depth camera, and a moveable platform,
• the processor system having at least one of a 3D scanner controller, an external computer, and a cloud computer configured for remote network access,
• the 3D scanner having a first light source, a first beam steering unit, a first angle measuring device, a second angle measuring device, and a first light receiver, the first light source configured to emit a first beam of light, the first beam steering unit configured to steer the first beam of light to a first direction onto a first object point, the first direction determined by a first angle of rotation about a first axis and a second angle of rotation about a second axis, the first angle measuring device configured to measure the first angle of rotation and the second angle measuring device configured to measure the second angle of rotation, the first light receiver configured to receive first reflected light, the first reflected light being a portion of the first beam of light reflected by the first object point, the first light receiver configured to produce a first electrical signal in response to the first reflected light, the first light receiver configured to cooperate with the processor system to determine a first distance to the first object point based at least in part on the first electrical signal, the 3D scanner configured to cooperate with the processor system to determine 3D coordinates of the first object point based at least in part on the first distance, the first angle of rotation and the second angle of rotation,
• a depth camera configured to move in conjunction with the 3D scanner;
• the moveable platform configured to carry the 3D scanner and the depth camera;
• determining with the processor system, in cooperation with the 3D scanner, 3D coordinates of a first collection of points on an object surface while the 3D scanner is fixedly located at a first registration position;
• obtaining by the 3D measuring device in cooperation with the processor system a plurality of depth-camera image sets, each of the plurality of depth-camera image sets being collected as the 3D measuring device moves from the first registration position to a second registration position, each of the plurality of depth-camera image sets being collected by the 3D measuring device at a different position relative to the first registration position;
• determining by the processor system a first translation value corresponding to a first translation direction, a second translation value corresponding to a second translation direction, and a first rotation value corresponding to a first orientational axis, wherein the first translation value, the second translation value, and the first rotation value are determined based at least in part on a fitting of the plurality of depth-camera image sets according to a first mathematical criterion;
• determining with the processor system, in cooperation with the 3D scanner, 3D coordinates of a second collection of points on the object surface while the 3D scanner is fixedly located at the second registration position;
• identifying by the processor system a correspondence among registration targets present in both the first collection of points and the second collection of points, the correspondence based at least in part on the first translation value, the second translation value, and the first rotation value;
• determining 3D coordinates of a registered 3D collection of points based at least in part on a second mathematical criterion, the correspondence among registration targets, the 3D coordinates of the first collection of points, and the 3D coordinates of the second collection of points;
• and
• storing the 3D coordinates of the registered 3D collection of points.