Handheld Apparatus For Quantifying Component Features

• US 20140021259A1
• Filed: 07/17/2012
• Published: 01/23/2014
• Est. Priority Date: 07/17/2012
• Status: Active Grant

• Current Assignee: Cognex Corporation
• Original Assignee: Carl W. Gerst, III
• Inventors: Moed, Michael C., Gerst, Carl W. III
• Granted Patent: US 9,286,530 B2
• Time in Patent Office: Days
• US Class Current: 235/472.01
• CPC Class Codes: G01B 11/06 for measuring thickness ; e.g. of sheet material thickness measurement by thermal means G01B21/085
• CPC Class Codes: G01B 11/25 by projecting a pattern, e.g. one or more lines, moiré fringes on the object G01B11/255 takes precedence ; image analysis for depth or shape recovery G06T7/50
• CPC Class Codes: G06K 2007/10524 Hand-held scanners
• CPC Class Codes: G06K 7/10544 by scanning of the records by radiation in the optical part of the electromagnetic spectrum
• CPC Class Codes: G06K 7/1417 2D bar codes
• CPC Class Codes: G06T 2207/10016 Video; Image sequence
• CPC Class Codes: G06T 2207/10152 Varying illumination
• CPC Class Codes: G06T 7/62 of area, perimeter, diameter or volume
• CPC Class Codes: G06V 10/141 Control of illumination
• CPC Class Codes: G06V 10/17 using hand-held instruments
• CPC Class Codes: G06V 10/242 by image rotation, e.g. by 90 degrees
• CPC Class Codes: G06V 10/245 by locating a pattern; Special marks for positioning

Abstract

A handheld device and method using the device, the device comprising a sensor receiving light from within a field of view (FOV) to generate a plurality of consecutive images of the FOV, a structured light source that is controllable to generate a plurality of light patterns, the source arranged to project at least one light patterns into the FOV where at least a portion of a pattern reflects from an object and is captured by the sensor and a processor to receive images, the processor programmed to control the source to project a pattern into the FOV, locate the pattern in at least one of the generated images, locate discontinuities in the pattern and use the discontinuities to measure at least one dimension.

Claims

1. A handheld device for determining at least one dimension of an object, the device comprising:

a hand held device housing structure;

a sensor mounted within the housing structure, the sensor receiving light from within a sensor field of view (FOV) to generate a plurality of consecutive images of the sensor FOV;

a structured light source that is controllable to generate a plurality of light patterns, the structured light source mounted to the housing for movement along with the sensor and arranged to project at least one of the plurality of light patterns into the sensor FOV where at least a portion of a projected light pattern reflects from an object located within the sensor FOV and is captured by the sensor; and

a processor linked to the sensor to receive images of the sensor FOV generated by the sensor, the processor programmed to control the structured light source to project a light pattern into the sensor FOV, locate the projected light pattern in at least one of the generated images, locate discontinuities in the projected light pattern and use the discontinuities to measure the at least one dimension of the object in the sensor FOV,

wherein the processor is programmed to analyze the projected light pattern in at least one of the generated images and select a subsequent projected light pattern as a function of the analysis.

2. The handheld device of claim 1 wherein the processor is programmed to identify different projected light patterns in at least a first and a second of the consecutive images and identifies discontinuities in each of the first and second images.

3. The handheld device of claim 2 wherein the processor is programmed to identify the at least one dimension of the object using the discontinuities in each of the first and second light patterns and to select one of the identified dimensions as the at least one dimension.

4. The handheld device of claim 1 wherein the processor is programmed to select the subsequent projected light pattern as a function of the identified at least one dimension associated with at least a subset of the prior image.

5. The handheld device of claim 1 wherein the processor is programmed to identify a first projected light pattern in a first of the consecutive images, identify discontinuities in the first identified light pattern and use the discontinuities in the first light pattern to identify a first instance of the at least one dimension of the object, identify a second projected light pattern in a second of the consecutive images, identify discontinuities in the second identified light pattern and use the discontinuities in the second light pattern to identify a second instance of the at least one dimension of the object, compare the first and second instances of the at least one dimension of the object and select a third light pattern to project into the FOV when the sensor obtains light to generate a third image by comparing the first and second instances of the at least one dimension.

6. The handheld device of claim 5 wherein the processor is further programmed to identify the third projected light pattern in the third image, identify discontinuities in the third identified light pattern and use the discontinuities in the third light pattern to identify a third instance of the at least one dimension of the object, and select a fourth light pattern to project into the FOV when the sensor obtains light to generate a fourth image by comparing the third instance of the at least one dimension to at least one of the first and second instances of the at least one dimension.

7. The handheld device of claim 1 wherein the processor is further programmed to identify projected light patterns in at least a subset of the plurality of generated images, identify discontinuities in each of the identified projected light patterns and use the discontinuities to identify a separate instance of the at least one dimension of the object for each of the subset of the plurality of generated images.

8. The handheld device of claim 7 wherein the processor selects the shortest of the separate instances of the at least one dimension as the at least one dimension.

9. The handheld device of claim 1 wherein the processor is programmed to continually obtain consecutive images using different light patterns until the processor identifies the at least one dimension of the object.

10. The handheld device of claim 1 wherein the processor is further programmed to compare the light patterns projected to the light patterns in the obtained images to identify a distance between the sensor and the surface of the object form which the light reflects and to us the identified distance as part of a calculation to identify the at least one dimension.

11. The handheld device of claim 1 wherein at least one of the projected light patterns is selected to generate a rough estimate of the distance between the sensor and the surface of the object from which light reflects and a subsequent one of the projected light patterns is selected to generate a more precise measurement of the distance between the sensor and the surface of the object from which the light reflects.

12. The handheld device of claim 1 wherein the processor is further programmed to identify machine readable code candidates in the obtained image and to attempt to decode identified code candidates.

13. The handheld device of claim 1 further including a user selectable activator linked to the processor for triggering the light source, sensor and processor to project light patterns, obtain images of the FOV and process the obtained images.

14. The handheld device of claim 1 wherein the structured light source includes a digital light processing (DLP) projector.

15. The handheld device of claim 14 wherein the processor uses a DLP metrology process to identify the at least one dimensional feature.

16. The handheld device of claim 14 wherein the processor is further programmed to identify machine readable code candidates in the obtained image and attempt to decode the code candidates and wherein the structured light source includes a digital light processing (DLP) projector, the DLP projector controlled by the processor to generate the light patterns in the images and to also generate light to illuminate code candidates within the FOV.

17. A handheld device for determining at least one dimension of an object, the device comprising:

a hand held device housing structure;

a sensor mounted within the housing structure, the sensor receiving light to within a sensor field of view (FOV) to generate images of the sensor FOV;

an illuminator mounted to the housing for movement along with the sensor and arranged to project a plurality of different light patterns into the sensor FOV where at least a portion of the projected light pattern reflects from an object located within the sensor FOV and is captured by the sensor; and

a processor linked to the sensor to receive images of the sensor FOV and linked to the illuminator for controlling selection of a first projected light pattern, the processor programmed to locate the first projected light pattern in a first obtained image, examine the first projected light pattern to identify a second light pattern that may be better suited to locate discontinuities useful in identifying the at least one dimension of the object in the sensor FOV, control the illuminator to project the second light pattern into the sensor FOV while a second image is obtained, locate the second pattern in the second image, locate discontinuities in the second pattern and use the discontinuities in the second light pattern to measure the at least one dimension of the object in the sensor FOV.

18. The handheld device of claim 17 wherein the illuminator is a digital light processing (DLP) projector.

19. The handheld device of claim 17 wherein the projector projects patterns into the FOV and the processor identifies discontinuities by comparing the projected patterns to the patterns identified in the obtained images.

20. A method for use with a handheld device for determining at least one dimension of an object, the handheld device including an image sensor having a field of view (FOV) and an illuminator mounted to a handheld housing so that the sensor and illuminator are manipulated as a single unit, the method comprising the steps of:

using a processor in the handheld device to perform the steps of;

projecting a first light pattern into the sensor FOV while an object is located within the sensor FOV;

obtaining an image of the sensor FOV;

locating the first projected light pattern in a first obtained image;

examining the first projected light pattern to identify a second light pattern that may be better suited to locate discontinuities useful in identifying at least one dimension of an object in the sensor FOV;

controlling the illuminator to project the second light pattern into the sensor FOV while a second image is obtained;

locating the second light pattern in the second image;

locating discontinuities in the identified second light pattern; and

using the discontinuities in the identified second light pattern to measure the at least one dimension of the object in the sensor FOV.