Method and apparatus for scanning lumber and other objects
AssigneeLMI Technologies Inc.
InventorsLeonard Metcalfe, Barry Dashner
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Abstract
Disclosed herein are TV Camera based and other electro-optical sensors and systems, providing affordable methods and apparatus for high speed determination of dimensions and other features of objects. Particular embodiments capable of fast and reliable acquisition of features of moving objects such as boards and wood products are disclosed. Preferred embodiments utilize laser triangulation range detection with at least two cameras viewing the same laser spot or line projected on the object.
Claims32
A method for determining the dimension of an object moving on a conveyor, comprising the steps of:
- providing a first triangulation based sensor unit, including a light source projecting a zone of light on the surface of said object and a TV camera, said first sensor unit oriented substantially such that a plane including the light source projection axis and the camera axis of said first sensor unit is in the direction of conveyor motion;
- providing a second triangulation based sensor unit, including a light source projecting a zone of light on the surface of said object and a TV camera, said second sensor unit oriented substantially such that a plane including the light source projection axis and the camera axis of said second sensor unit is in the direction of conveyor motion;
- positioning said sensor units so that said first sensor unit views the object moving toward it due to the conveyor motion, while the second sensor unit views the object moving away from it;
- without using a geometric model of said object, analyzing the outputs of said sensor units;
- and
- from said analysis determining at least one dimension of said object.
An improvement in measuring boards on a conveyor using optical triangulation sensors, comprising the steps of:
- projecting a zone of light on said board;
- without using a geometric model of said board, predicting data relating to the likely location of the board surface, and therefore the image of the zone on the board;
- and
- imaging said zone with a TV camera having a photo-detector array which can be addressed such that the pixels of the array which are interrogated are those in the vicinity of the expected location of the image of the zone, given said predicted board surface location.
Dependencies are inferred from the claim text.