| 主权项 |
1. A method of object measurement to determine 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, wherein the projector and the camera are fixed in relation to one another, there being a baseline between the projector and the camera, the baseline being a line segment that has a distance equal to a baseline distance, the projector having a light source configured to emit projected light along a general direction of propagation given by a first axis, the assembly having a central plane that includes the first axis and the baseline, the projected light having any of a plurality of patterns in a first plane, the first plane being perpendicular to the first axis, the camera having a lens and a photosensitive array, the camera having a camera field of view, the lens configured to image a reflected portion of the projected light that is within the camera field of view onto the photosensitive array and to produce an electrical signal in response; providing a processor electrically coupled to the projector and the camera; selecting by the processor a first pattern from among the plurality of patterns; emitting from the projector onto the surface, in a first instance, a first projected light having the first pattern; reflecting into the camera a portion of the first projected light as a first reflected light; forming with the lens a first image of the first reflected light on the photosensitive array 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, the first electrical signal and the baseline distance; determining with the processor a simulation in which 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 the angle of reflection of at least one of the secondary rays intersects the object to form a second image on the photosensitive array that interferes with the first reflected light; selecting by the processor a second pattern from among the plurality of patterns, the second pattern being in the first plane, the second pattern being a single line stripe or a single spot, the second pattern based at least in part on the determining that the angle of reflection of at least one of the secondary rays intersects the object to form a second image on the photosensitive array that interferes with the first reflected light; emitting from the projector onto the surface, in a second instance, a second projected light having the second pattern; reflecting into the camera a portion of the second projected light as a second reflected light; forming with the lens a second image of the second reflected light on the photosensitive array and producing a second electrical signal in response; determining with the processor 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, the second electrical signal, and the baseline distance; and storing the second set of 3D coordinates. |
