Method for safely identifying moving object

• US 9,405,987 B2
• Filed: 07/15/2011
• Issued: 08/02/2016
• Est. Priority Date: 07/15/2010
• Status: Expired due to Fees

• Current Assignee: The European Atomic Energy Community (Euratom)
• Original Assignee: The European Atomic Energy Community (Euratom)
• Inventors: Sequeira, Vitor, Bostrom, Gunnar
• Primary Examiner(s): Anyikire, Chikaodili E
• Application Number:
  US13/809,638
• Publication Number:
  US 20130286165A1
• Time in Patent Office: 1,845 Days
• Field of Search: 348/48
• US Class Current: 1/1
• CPC Class Codes: G01S 17/87 Combinations of systems using electromagnetic waves other than radio waves
• CPC Class Codes: G01S 17/88 Lidar systems specially adapted for specific applications
• CPC Class Codes: G01S 17/89 for mapping or imaging
• CPC Class Codes: H04N 13/243 using three or more 2D image sensors

Abstract

A non-contact identification and measurement method for identifying moving three-dimensional objects within an identification area, comprising the steps of detecting the presence of a moving object by scanning said identification area with a first eye-safe laser-based range detector system; discriminating between an object safe to be identified and an object not to be identified; for an object safe to be identified, activating a second laser-camera system and determining the speed and position of said object with said second laser-camera system; when said object safe to be identified reaches a position located in an active measurement area within said identification area, activating a third laser-camera system to acquire range data of said object.

Claims

1. A non-contact acquisition and measurement method for identifying moving three-dimensional objects within an identification area, comprising the steps of:

(1) detecting the presence of a moving object by scanning said identification area with a first eye-safe laser-camera system,

(2) discriminating between an object safe to be identified and an object not to be identified,

(3) for an object to be identified, activating a second laser-camera system and determining the speed and position of said object with said second laser-camera system,

(4) when said object to be identified reaches a position located in an active measurement area within said identification area, activating a third laser-camera system to acquire range data of said object, and

wherein said first eye-safe laser is a Class 1 or Class 1M laser and said second and third lasers are at least Class 2 lasers;

wherein discriminating step (2) comprises the substeps of;

(2a) comparing consecutively acquired images and changes therein to a set of criteria, wherein said set of criteria define the shapes of moving objects to be identified, and

(2b) if said changes do not correspond to any of said criteria, deactivating any active second and third laser-camera system and reverting to step (1).

2. The method according to claim 1, wherein said first laser-camera system is a laser-based range detector system or a laser-based range detector system based on Time-of-Flight measurement principle.

3. The method according to claim 2, wherein said second and/or third laser-camera systems are based on laser triangulation and 30 camera.

4. The method according to claim 1, wherein said first, second and/or third laser-camera systems comprise a plurality of spatially separated laser-camera devices.

5. The method according to claim 1, wherein said first eye-safe laser is a Class 1 laser, said second and third lasers are at least Class 3 lasers.

6. The method according to claim 1, wherein presence detecting step (1) comprises the substeps of:

(1a) scanning said identification area with at least one Class 1 safety laser beam source and acquiring images with an image acquisition device associated to each source using laser triangulation,

(1b) storing successively acquired images within an acquired image storing device,

(1c) identifying the presence of a moving object within the identification area by comparing consecutively acquired images to detect changes within the image, and

(1d) if no changes have been detected, reverting to substep (1a).

7. The method according to claim 1, wherein presence detecting step (1) comprises the substeps of:

(1a′

) scanning said identification area with at least one Class 1 or 1M eye-safe laser beam source and acquiring spatial information with a range acquisition device associated to each source,

(1b′

) analysing sequentially acquired spatial information from said range acquisition device and evaluate the presence of objects in one or more pre-defined rectangular zones, whose respective longitudinal axis is essentially parallel to the direction of movement of the moving objects,

(1c′

) based on detected presence of objects in some zones and absence of hits in other zones, a change can be identified, and

(1d′

) if no changes have been detected, reverting to substep (1a′

).

8. The method according to claim 1, wherein speed and position determining step (3) comprises the substeps of:

(3a) activating a further Class 2 laser beam source scanning an active measurement area within said identification area and an image acquisition device associated to said source,

(3b) storing successively acquired images within an acquired image storing device,

(3c) comparing consecutively acquired images to determine speed and position of said moving object, and

(3d) activating measurement step (4) when the moving object reaches a position inside a range data measurement area within said active measurement area, and deactivating step (4) when the moving object leaves said range data measurement area.

9. The method according to claim 1, wherein measuring step (4) comprises the substeps of:

(4a) activating at least one Class 3 laser beam source, scanning a range data measurement area within said active measurement area and acquiring range data with a range data acquisition device associated to each source using laser triangulation, and

(4b) storing acquired range data of said object within a range data storing device.

10. The method according to claim 9, wherein measuring step (4) further comprises the sub step of:

(4c) comparing said acquired range data of an object with previously acquired data to identify objects already known.

11. The method according to claim 1, further comprising activating visual and/or acoustic safety signals before activating third laser-camera system or second and third laser-camera systems.

12. The method according to claim 11, wherein said visual and/or acoustic safety signals are continued when third laser-camera system is active or when second and third laser-camera systems are active.

13. The method according to claim 1, wherein the moving objects are UF6 cylinders.

14. A device for implementing the method according to claim 1.

15. The device according to claim 14, comprising a first eye-safe laser-based range detection system capable of scanning an identification area, a second laser-camera system capable of scanning a reduced area within said identification area and a third laser-camera system capable of scanning a reduced area within said identification area, a storing device and a processing unit, wherein the activation and deactivation of the second and third laser-camera systems are controlled by the processing unit based on successively acquired data from said first laser-based range detection system.

16. The method according to claim 1, wherein at least said third laser is a Class 3 or 4 laser.