Entity detection system and method for monitoring an area

• US 9,507,050 B2
• Filed: 12/13/2010
• Issued: 11/29/2016
• Est. Priority Date: 12/14/2009
• Status: Active Grant

• Current Assignee: Montel
• Original Assignee: Montel
• Inventors: Mimeault, Yvan, Dubois, Martin
• Primary Examiner(s): Phan, Hai
• Assistant Examiner(s): Yu, Royit
• Application Number:
  US13/505,543
• Publication Number:
  US 20120218107A1
• Time in Patent Office: 2,178 Days
• Field of Search: 340555-557, 340/565, 340/540, 340/568.5, 250/222.1, 250/221
• US Class Current: 1/1
• CPC Class Codes: G01V 8/20 using multiple transmitters or receivers

Abstract

An entity detection method and system are provided for monitoring an area. The method comprises providing an illuminated band extending continuously along an extremity of the area; providing an optical detector having an image sensor adapted to capture an image, the illuminated band being viewable by the image sensor and being capturable in the image, a space between the band and the image sensor being part of the area; storing a detection threshold; analyzing the image to detect a discontinuity in the continuous illuminated band apparent on the image, comparing the detected discontinuity to the detection threshold; and indicating a status of the area to be one of a presence of an entity and an absence of the entity based on the comparing.

Claims

1. An entity detection system for monitoring an area, said area created between a mobile unit and an opposing unit, said mobile unit extending along a longitudinal axis and having a detection side, said opposite unit extending parallel to the longitudinal axis and having a detection side facing the detection side of the mobile unit, the mobile unit being movable between an open positon wherein the mobile unit and the opposing unit are spaced-apart and a longitudinally extending aisle is defined therebetween and a closed position wherein the detection sides of the mobile unit and the opposing unit are juxtaposed and said aisle collapses, said longitudinally extending aisle being said area, said entity detection system comprising:

a distributed light source adapted to provide an illuminated band, said illuminated band extending longitudinally continuously along the longitudinal axis of a first one of said detection side of said mobile unit and said detection side of said opposing unit;

at least one marker provided on a terminal minor portion of said illuminated band, a major portion of said illuminated band disposed adjacent to the minor portion and not having said at least one marker, said at least one marker generating a marking pulse using a specific source indicating an end of said illuminated band, wherein the marking pulse is indicative of a position of the mobile unit;

an optical detector, said optical detector being provided at a second one of said detection side of said mobile unit and said detection side of said opposing unit, said second one being different than said first one, said optical detector having an image sensor adapted to capture an image, the illuminated band and said at least one marker being viewable by the image sensor and being capturable in said image, a space between said distributed light source and said image sensor being part of said area;

a memory for storing a detection threshold and a marker image profile, wherein said detection threshold includes an intensity amplitude threshold and a length threshold; and

a processor receiving said image from said image sensor, said processor having an image analyzer for analyzing said image to detect a discontinuity and the marking pulse in said continuous illuminated band apparent on said image and to determine an intensity amplitude and a length of said discontinuity, said discontinuity being caused by a presence of an entity in said area, between said distributed light source and said image sensor, said entity blocking light emitted from said illuminated band toward said image sensor, said processor capable of comparing said marking pulse to said marker image profile to confirm that said marking pulse is an image of said marker and of determining a location of an end of said continuous illuminated band on said image, said location of said end of said continuous illuminated band on said image being dependent upon said position of said mobile unit with respect to said opposing unit;

said processor further comprising a discontinuity comparator for comparing said intensity amplitude of said detected discontinuity to said intensity amplitude threshold and said length of said discontinuity to said length threshold, said intensity amplitude threshold and said length threshold being a function of said position of said mobile unit with respect to said opposing unit and for determining a status of said area to be a presence of an entity if said length of said discontinuity is longer than said length threshold and said intensity amplitude of said discontinuity is smaller than said intensity amplitude threshold; and

said processor also comprising a status indicator for indicating said status of said area to be one of said presence of said entity and an absence of said entity based on said comparing said intensity amplitude and said length and on said location of said end of said continuous illuminated band.

2. The entity detection system as claimed in claim 1, wherein the illuminated band is entirely viewable by the optical detector.

3. The entity detection system of claim 1, further comprising a plurality of illuminated bands extending continuously along all extremities of said area.

4. The entity detection system of claim 1, further comprising a plurality of optical detectors.

5. The entity detection system of claim 1, further comprising an alarm generator for generating an alarm if said status indicator indicates said status of said area to be presence of an entity.

6. The entity detection system of claim 5, further comprising a visual indicator for indicating said status of said area based on said alarm.

7. The entity detection system of claim 1, wherein said illuminated band emits at least one of visible light and invisible light.

8. The entity detection system as claimed in claim 6, wherein said visual indicator is a color of visible light illumination of said illuminated band.

9. The entity detection system of claim 1, wherein said mobile unit is a mobile storage unit of a mobile storage.

10. The entity detection system as claimed in claim 9, wherein said opposing unit is one of a wall, a second mobile storage unit and a stationary storage unit.

11. The entity detection system of claim 1, further comprising a second optical detector and a second illuminated band, said detection side of said mobile unit and said detection side of said opposing unit each having said illuminated band extending continuously along the longitudinal axis, said detection side of said mobile unit and said detection side of said opposing unit each having said optical detector.

12. The entity detection system as claimed in claim 11,

wherein

said processor receives two images, one image from each said optical detector;

said image analyzer analyzes, said discontinuity comparator compares and said status indicator indicates for each image of said two images;

wherein said processor further comprises a status determiner for determining a status of said aisle to be occupied if at least one of said status indicated by said status indicator is said presence of an entity and for determining a status of said aisle to be empty if both of said status indicated by said status indicator is said absence of an entity.

13. The entity detection system of claim 1, further comprising a drive arrangement for movement of the mobile unit, along a path, one of toward and away from the opposing unit, to open and close the aisle, a controller for the drive arrangement controlling the movement of the mobile unit, a user input switch for the controller for activating the drive arrangement for movement of the mobile unit, said detection unit further comprising an alarm generator for generating an alarm if said image analyzer determines said status of said area to be presence of an entity, the controller blocking movement of the mobile unit upon said alarm.

18. The entity detection system of claim 1, wherein the illuminated band is a retro-reflective band, the system further comprising a punctual light source emitting light toward the retro-reflective band.

14. An entity detection method for monitoring an area, said area created between a mobile unit and an opposing unit, said mobile unit extending along a longitudinal axis and having a detection side, said opposite unit extending parallel to the longitudinal axis and having a detection side facing the detection side of the mobile unit, the mobile unit being movable between an open positon wherein the mobile unit and the opposing unit are spaced-apart and a longitudinally extending aisle is defined therebetween and a closed position wherein the detection sides of the mobile unit and the opposing unit are juxtaposed and said aisle collapses, said longitudinally extending aisle being said area, said entity detection method comprising:

providing a distributed light source adapted to generate an illuminated band, said illuminated band extending longitudinally continuously along the longitudinal axis of a first one of said detection side of said mobile unit and said detection side of said opposing unit;

providing at least one marker provided on a terminal minor portion of said illuminated band, a major portion of said illuminated band disposed adjacent to the minor portion and not having said at least one marker, said at least one marker generating a marking pulse using a specific source indicating an end of said illuminated band, wherein the marking pulse is indicative of a position of the mobile unit;

providing an optical detector, said optical detector being provided at a second one of said detection side of said mobile unit and said detection side of said opposing unit, said second one being different than said first one, said optical detector having an image sensor adapted to capture an image, the illuminated band and said at least one marker being viewable by the image sensor and being capturable in said image, a space between said distributed light source and said image sensor being part of said area;

storing a detection threshold and a marker image profile, wherein said detection threshold includes an intensity amplitude threshold and a length threshold;

analyzing said image to detect a discontinuity in said continuous illuminated band apparent on said image and to determine an intensity amplitude and a length of said discontinuity, said discontinuity being caused by a presence of an entity in said area, between said distributed light source and said image sensor, said entity blocking light emitted from said illuminated band toward said image sensor;

analyzing said image to detect the marking pulse in said continuous illuminated band apparent on said image;

comparing said detected discontinuity to said detection threshold by comparing said intensity amplitude of said detected discontinuity to said intensity amplitude threshold and said length of said discontinuity to said length threshold, said intensity amplitude threshold and said length threshold being a function of said position of said mobile unit with respect to said opposing unit;

comparing said marking pulse to said marker image profile to confirm that said marking pulse is an image of said marker;

determining a location of an end of said continuous illuminated band on said image, said location of said end of said continuous illuminated band on said image being dependent upon said position of said mobile unit with respect to said opposing unit;

determining a status of said area to be a presence of an entity if said length of said discontinuity is longer than said length threshold and said intensity amplitude of said discontinuity is smaller than said intensity amplitude threshold; and

indicating said status of said area to be one of said presence of said entity and an absence of said entity based on said comparing said intensity amplitude and said length and on said location of said end of said continuous illuminated band.

15. The entity detection method as claimed in claim 14 wherein a plurality of discontinuity are detected in said analyzing step.

16. The entity detection method of claim 14, wherein said mobile unit is a mobile storage unit of a mobile storage.

17. The entity detection method as claimed in claim 14, wherein

said storing said image comprises storing said two images, one image from each said optical detector;

said analyzing, comparing and indicating comprise analyzing, comparing and indicating for each image of said two images;

further comprising determining a status of said aisle to be occupied if at least one of said status is said presence of an entity and for determining a status of said aisle to be empty if both of said status is said absence of an entity.