System for detecting optically invisible objects provided with encoding

• US 20040113623A1
• Filed: 10/24/2003
• Published: 06/17/2004
• Est. Priority Date: 12/28/2000
• Status: Abandoned Application

• Current Assignee: Plymouth Francaise
• Original Assignee: Plymouth Francaise
• Inventors: Belloir, Fabien
• Application Number:
  US10/250,377
• Publication Number:
  US 20040113623A1
• Time in Patent Office: Days
• US Class Current: 324/326
• CPC Class Codes: F16L 1/11 for the detection or protection of pipes in the ground
• CPC Class Codes: G01V 15/00 Tags attached to, or associated with, an object, in order to enable detection of the object record carriers for use with machines having a detectable tag or marker G06K19/00

Abstract

The invention concerns a system for detecting and identifying optically invisible objects, provided with encoding, wherein each object (2) is provided with encoding elements in the form of a series of thin electrically conductive elements (3, 4, 5), capable of being detected by electromagnetic process, forming each a surface of predetermined dimensions and arranged in or on an electrically insulating protective support, said elements being spaced apart from one another by intervals likewise of predetermined value. It comprises an electromagnetic detector (8) including at least an emitting coil and a reception coil, designed to deliver to the detector at least two signals of the code borne by an object and its surroundings, means being provided for processing said signals so as to reproduce the signature of the single code and thereby locate and identify the encoded object.

Claims

1. A system for detecting and identifying optically invisible objects which are provided with a coding, in which each object (2) is provided with coding elements exhibiting the form of a succession of electrically conducting elements (3, 4, 5) of small thickness, which are electromagnetically detectable, each forming a surface of predetermined dimensions and arranged in or on an electrically insulating protective support, these elements being separated from one another by intervals likewise of predetermined value, characterized in that it comprises an electromagnetic detector (8) including at least one transmission coil (10) and at least one reception coil (13), which are devised so as to provide the detector with at least two signals representative of the code carried by an object and of its environment, means being envisaged for processing these signals so as to reconstruct the signature of the single code and thus to locate and identify the coded object.

2. The system as claimed in claim 1, characterized in that the detector (8) comprises a computer receiving the various signals and reconstructing the exact code of the object by mathematical methods based for example on independent component analysis or derivatives thereof such as source separation methods.

3. The system as claimed in either of claims 1 and 2, characterized in that the detector (8) is associated with a sensor making it possible to measure its relative displacement and triggering an operation of processing the signals received independently of the rate of movement of the operator, such as a wheel (9) associated with an incremental counter (15) triggering an operation of processing the signals received, after displacement of the detector by a predetermined distance.

4. The system as claimed in claim 3, characterized in that the adjustable shift of displacement of the detector (8) between two processing operations is of the order of 4 mm.

5. The system as claimed in one of claims 1 to 4, characterized in that the conducting coding elements (3, 4, 5) on the objects to be detected are integrated into the latter by one of the following processes:

adhesive bonding, hooping, double or triple extrusion, painting, spraying, injection, fusion.

6. The system as claimed in one of claims 1 to 5, characterized in that the detector (8) comprises a transmission coil (10) and a reception coil (13), the transmission coil (10) transmitting electromagnetic signals of different frequencies successively and with a small time offset.

7. The system as claimed in one of claims 1 to 5, characterized in that the detector (8) comprises at least one transmission coil (10) and several mutually staggered reception coils (13).

8. The system as claimed in claim 7, characterized in that the detector (8) comprises a transmission coil (10) transmitting an electromagnetic signal at a specified frequency and three reception coils (13) arranged along a circle and mutually offset by 90°

.

9. The system as claimed in claims 1 to 8, characterized in that the coils (10, 13) are two-sided flat, etched coils including epoxy supports.

10. The system as claimed in one of claim 1 to 9, characterized in that the frequency of the electromagnetic signal transmitted by the transmission coil or coils is of the order of 10 KHz.