Dimensioning and barcode reading system

摘要

A system and method for calibrating a barcode scanning tunnel comprises providing a scanning tunnel having a moveable surface, a camera, and a dimensioning device. Orientations of the dimensioning device and camera are estimated. Instances of a calibration object on the moveable surface are acquired by the dimensioning device and the camera, and a relationship is defined between the two devices. A calibration object is moved along the moveable surface through the devices' fields of view, controlling the camera's focal distance according to the relationship, so that the dimensioning device and the camera acquire instances of the calibration object, and the relationship is revised.

主权项

1. A method of calibrating a barcode scanning tunnel, said method comprising:
providing a scanning tunnel having
a moveable surface,a camera having a sensor and optics that direct an image to the sensor from a field of view of the camera that includes the moveable surface, anda dimensioning device disposed with respect to the moveable surface so that the dimensioning device acquires dimensions of objects on the moveable surface passing through a field of view of the dimensioning device; estimating an orientation of the dimensioning device in the tunnel; estimating an orientation of the camera in the tunnel; disposing a first calibration object in the dimensioning device field of view and measuring an instance of a first dimension therein that relates to the calibration object and wherein the instance of the first dimension is dependent upon the orientation of the dimensioning device; disposing the first calibration object in the camera field of view and measuring an instance of a second dimension therein that corresponds to the first dimension and wherein the instance of the second dimension is dependent upon the orientation of the camera; based on the instance of the first dimension, the instance of the second dimension, the estimated orientation of the dimensioning device, and the estimated orientation of the camera, defining a relationship that relates an instance of the first dimension for an object on the moveable surface to control of a camera focal distance to the object on the moveable surface; disposing a second calibration object on the moveable surface and moving the second calibration object through the dimensioning device field of view and the camera field of view in a direction of travel of the moveable surface, wherein the dimensioning device field of view is upstream of the camera field of view with respect to the direction of travel, and wherein actual dimensions of one or more features of the second calibration object are predetermined; measuring, by the dimensioning device as the second calibration object moves through the dimensioning device field of view, an instance of the first dimension with respect to the second calibration object and an instance of a dimension of a first said feature of the second calibration object, wherein measurement of the instance of the dimension of the first feature corresponds to the orientation of the dimensioning device; controlling the focal distance in response to the instance of the first dimension measured at the measuring step, according to the relationship; after the controlling step, measuring, by the camera as the second calibration object moves through the camera field of view, an instance of a dimension of a second said feature of the second calibration object, wherein measurement of the instance of the dimension of the second feature corresponds to the orientation of the camera; revising an estimate of the orientation of the dimensioning device based on the instance of the dimension of the first feature; revising an estimate of the orientation of the camera based on the instance of the dimension of the second feature; and revising the relationship based on the revised estimate of the orientation of the dimensioning device and on the revised estimate of the orientation of the camera.