DIAGNOSING MULTIPATH INTERFERENCE AND ELIMINATING MULTIPATH INTERFERENCE IN 3D SCANNERS USING PROJECTION PATTERNS

摘要

A noncontact optical three-dimensional measuring device that includes a projector and a camera; a processor electrically coupled to the projector and the camera; and computer readable media which, when executed by the processor, causes the first signal to be collected at a first time and the second signal to be collected at a second time different than the first time and determines three-dimensional coordinates of a first point on the surface based at least in part on the first signal and the distance and determines three-dimensional coordinates of a second point on the surface based at least in part on the second signal and the distance.

主权项

1. A method of determining three-dimensional (3D) coordinates of points on a surface of an object, the method comprising:
providing an assembly that includes a projector and a camera, the projector having a light source configured to emit projected light the projected light having any of a plurality of patterns, the camera having a lens and a photosensitive array, the camera having a camera field of view; providing a processor electrically coupled to the projector and the camera; emitting from the projector onto the surface, in a first instance, a first projected light having a first pattern; acquiring with the camera a first image of the first projected light and producing a first electrical signal in response; determining with the processor a first set of 3D coordinates of first points on the surface, the first set based at least in part on the first pattern and the first electrical signal; determining with the processor a simulation in which, in the first instance, the processor projects first rays from the projector to the first points and calculates for each first ray an angle of reflection of a secondary ray from each of the first points and determining that at least one of the secondary rays intersects the object within the field of view of the camera; selecting by the processor, in a second instance, a second pattern from among the plurality of patterns, the second pattern being a single line stripe or a single spot, the selection of the second pattern based at least in part on the determining that at least one of the secondary rays intersects the object within the field of view of the camera; emitting from the projector onto the surface, in the second instance, a second projected light having the second pattern; acquiring with the camera a second image of the second projected light and producing a second electrical signal in response; determining with the processor, in the second instance, a second set of 3D coordinates of at least one second point on the surface, the second set based at least in part on the second pattern and the second electrical signal; and storing the second set of 3D coordinates.