Method and System for Optoelectronic Detection and Location of Objects

• US 20080310676A1
• Filed: 06/15/2007
• Published: 12/18/2008
• Est. Priority Date: 06/15/2007
• Status: Active Grant

• Current Assignee: Cognex Corporation
• Original Assignee: Cognex Corporation
• Inventors: Silver, William M.
• Granted Patent: US 8,718,319 B2
• Time in Patent Office: Days
• US Class Current: 382/103
• CPC Class Codes: G01V 8/00 Prospecting or detecting by optical means
• CPC Class Codes: G06T 2207/10016 Video; Image sequence
• CPC Class Codes: G06T 2207/30164 Workpiece; Machine component
• CPC Class Codes: G06T 7/0008 checking presence/absence
• CPC Class Codes: G06T 7/74 involving reference images or patches
• CPC Class Codes: G06V 10/24 Aligning, centring, orientation detection or correction of the image
• CPC Class Codes: G06V 2201/06 Recognition of objects for industrial automation

Abstract

Disclosed are methods and systems for optoelectronic detection and location of moving objects. The disclosed methods and systems capture one-dimensional images of a field of view through which objects may be moving, make measurements in those images, select from among those measurements those that are likely to correspond to objects in the field of view, make decisions responsive to various characteristics of the objects, and produce signals that indicate those decisions. The disclosed methods and systems provide excellent object discrimination, electronic setting of a reference point, no latency, high repeatability, and other advantages that will be apparent to one of ordinary skill in the art.

Claims

1. A system for locating an object, comprising:

an optical sensor capable of making light measurements in a field of view;

a motion process that provides relative motion between the object and the optical sensor, such that

the object passes through the field of view; and

the object crosses a reference position at a reference time;

a process that determines an estimate of the reference time by predicting the reference time; and

a signaling process that produces a signal at a time that is responsive to the estimate of the reference time.

2. A system for locating an object, comprising:

an optical sensor capable of making light measurements in a field of view;

a motion process that provides relative motion between the object and the optical sensor, such that

the object passes through the field of view; and

the object crosses a reference position at a reference time;

a process that determines an estimate of the reference time; and

a signaling process that uses the estimate of the reference time to produce a signal at a signal time, wherein there is no latency between the reference time and the signal time.

3. A method for locating an object, comprising:

using an optical sensor to make light measurements in a field of view;

providing relative motion between the object and the optical sensor in a direction of motion, wherein

the object passes through the field of view; and

the object crosses a reference position at a reference time;

determining an estimate of the reference time by predicting the reference time; and

producing a signal at a time that is responsive to the estimate of the reference time.

4. A method for locating an object, comprising:

using an optical sensor to make light measurements in a field of view;

providing relative motion between the object and the optical sensor in a direction of motion, wherein

the object passes through the field of view; and

the object crosses a reference position at a reference time;

determining an estimate of the reference time; and

using the estimate of the reference time to produce a signal at a signal time, wherein there is no latency between the reference time and the signal time.