Method and system for determining the position of a wanted object which is positioned in a row of objects and is provided with a transponder

• US 6,674,361 B2
• Filed: 07/11/2001
• Issued: 01/06/2004
• Est. Priority Date: 07/13/2000
• Status: Expired due to Fees

• Current Assignee: NXP B.V. (NXP Semiconductors NV)
• Original Assignee: Koninklijke Philips Electronics N.V. (Koninklijke Philips N.V.)
• Inventors: Cernusca, Michael, Morgenroth, Dirk
• Primary Examiner(s): Crosland, Donnie L.
• Application Number:
  US09/902,921
• Publication Number:
  US 20020014965A1
• Time in Patent Office: 909 Days
• Field of Search: 340/505, 340/572.1, 340/572.3, 340/572.4, 340/572.5, 340/572.2, 340/5.86, 340/5.9, 340/5.91, 340/5.92, 340/10.1, 340/10.51, 235/375, 235/381, 235/385, 705/22, 705/28
• US Class Current: 340/505
• CPC Class Codes: G06K 7/0008 General problems related to the reading of electronic memory record carriers, independent of its reading method, e.g. power transfer
• CPC Class Codes: G06K 7/10079 the collision being resolved in the spatial domain, e.g. temporary shields for blindfolding the interrogator in specific directions
• CPC Class Codes: G06K 7/10356 using a plurality of antennas, e.g. configurations including means to resolve interference between the plurality of antennas
• CPC Class Codes: G06Q 10/087 Inventory or stock management, e.g. order filling, procurement or balancing against orders
• CPC Class Codes: G06Q 20/203 Inventory monitoring

Abstract

In a method and a system (1) for determining a position (d) of a wanted object (BKn) fitted with a transponder (TRn), scanning signals (INTnle, INTnri) with current strengths (Ire, Iri) changed (reduced) in steps and starting from a starting value (maximum value) are supplied to a left transmission coil (9) and separately therefrom to a right transmission coil (10), and it is determined by detection means (15, 16) when the transponder (TRn) associated with the wanted object (BKn) has changed its behavior between delivery and non-delivery of its response signal (RESn), whereupon those values V(Ii+1), V(Ik+1) of the changed (reduced) current strengths (Ii+1, Ik+1) are determined at which the transponder (TRn) has changed its behavior between delivery and non-delivery of its response signal (RESn), and the position (d) of the wanted object (BKn) is subsequently determined from said values V(Ii+1), V(Ik+1).

Claims

1. A method of determining a position (d) of a wanted object (BKn) which is positioned in a row (2) of objects (BK), said objects (BK) being each provided with a transponder (TR), characterized in that

a left scanning signal (INTnle) for triggering a response signal (RESn) of a transponder (TRn), with which the wanted object (BKn) is fitted, is supplied by a left scanning signal generation means (12), with a left current strength (Ile) having a starting value (I1), to a left transmission coil (9) which is provided at a left-hand end of the row (2) of objects (BK), and in that

subsequently the left scanning signal (INTnle) for triggering the response signal (RESn) of the transponder (TRn), with which the wanted object (BKn) is fitted, is supplied to the left transmission coil (9) by the left scanning signal generation means (12), with left current strengths (I2, . . . , Ii+1, Ii) changed in steps, such that a change in accordance with a minimum current value difference is carried out upon changing of the left current strength (Ile), and in that

it is ascertained for each step whether the transponder (TRn), with which the wanted object (BKn) is fitted, has given off the response signal (RESn) triggered by the left scanning signal (INTnle) supplied to the left transmission coil (9) by the left scanning signal (12), and in that a value V(Ii) is determined of that changed left current strength (Ii) of the left scanning signal (INTnle) with which after a change of the left current signal (Ile) in accordance with the minimum current value difference the left scanning signal (INTnle) was supplied to the left transmission coil (9) by the left scanning signal (12), and in that

a right scanning signal (INTnri) for triggering the response signal (RESn) from the transponder (TRn), with which the wanted object (BKn) is fitted, is supplied in a first step by a right scanning signal generation means (13) to a right transmission coil (10), which is provided at a right-hand end of the row (2) of objects (BK), with a right current strength (Iri) having a starting value (I1), and in that subsequently the right scanning signal (INTnri) for triggering the response signal (RESn) of the transponder (TRn), with which the wanted object (BKn) is fitted, is supplied to the right transmission coil (10) by the right scanning signal generation means (13) with right current strengths (I2, I3, .., Ik+1, Ik) changed in steps, such that a change in accordance with a minimum current value difference is carried out upon changing of the right current strength (Ile), and in that

it is ascertained for each step whether the transponder (TRn), with which the wanted object (BKn) is fitted, has given off the response signal (RESn) triggered by the right scanning signal (INTnri) supplied to the right transmission coil (10) by the right scanning signal generation means (13), and in that a value V(Ik) is determined of that changed right current strength (Ik) of the right scanning signal (INTnri) with which after a change in the right current strength (Iri) in accordance with the minimum current value difference the right scanning signal (INTnri) was supplied to the right transmission coil (10) by the right scanning signal generation means (13), and in that

the position (d) of the wanted object (BKn) is determined from the knowledge of said value V(Ii) of the determined changed left current strength (Ii) of the left scanning signal (INTnle) and from the knowledge of said value V(Ik) of the determined changed right current strength (Ik) of the right scanning signal (INTnri).

2. A method as claimed in claim 1, characterized in that the left scanning signal (INTnle) is supplied to the left transmission coil (9) with a maximum left current strength (I1) in the first step, and in that the right scanning signal (INTnri) is supplied to the right transmission coil (10) with a maximum right current strength (Ii) in the first step.

3. A method as claimed in claim 2, characterized in that

the left scanning signal (INTnle) is supplied to the left transmission coil (9) with left current strengths (I2, . . . , Ii+1, Ii) reduced in steps of substantially constant current value difference, and in that

the value V(Ii) is determined of that changed left current strength (Ii) of the left scanning signal (INTnle) at which the transponder (TRn), with which the wanted object (BKn) is fitted, has changed its behavior between delivery and non-delivery of the response signal (RESn) triggered by means of the left scanning signal (INTnle) supplied to the left transmission coil (9), and in that

the right scanning signal (INTnri) is supplied to the right transmission coil (10) with right current strengths (I2, I3, . . . , Ii+1, Ii) reduced in steps of substantially constant current value difference, and in that

the value V(Ik) of that changed right current strength (Ik) of the right scanning signal (INTnri) is determined at which the transponder (TRn), with which the wanted object (BKn) is fitted, has changed its behavior between delivery and non-delivery of the response signal (RESn) triggered by means of the scanning signal (INTnri) supplied to the right transmission coil (10).

4. A method as claimed in claim 3, characterized in that the left scanning signal (INTnle) is supplied to the left transmission coil (9) with left current strengths (I2, . . . , Ii1+1, I1) reduced in steps of substantially constant current value difference, and in that

the right scanning signal (INTnri) is supplied to the right transmission coil (10) with right current strengths (I2, I3, . . . , Ik+1, Ik) reduced in steps of substantially constant current value difference.

5. A method as claims in claim 4, characterized in that

the value V(Ii+1) of that reduced left current strength (Ii+1) of the left scanning signal (INTnle) is determined and stored at which the transponder (TRn), with which the wanted object (BKn) is fitted, has given off the response signal (RESn) triggered by the left scanning signal (INTnle) supplied to the left transmission coil (9) for the last time before the transponder (TRn) for the first time has not given such a response signal (RESn) any more, and in that

the value V(Ik+1) of that reduced right current strength (Ik+1) of the right scanning signal (INTnri) is determined and stored at which the transponder (TRn), with which the wanted object (BKn) is fitted, has delivered the response signal (RESn) triggered by the right scanning signal (INTnri) supplied to the right transmission coil (10) for the last time before the transponder (TRn) for the first time has not given such a response signal (RESn) any more, and in that

the position (d) of the wanted object (BKn) is determined from said value V(Ii+1) of the determined reduced left current strength (Ile) of the left scanning signal (INTnle) and from said value V(Ik+1) of the determined reduced right current strength (Iri of the right scanning signal (INTnri).

6. A method as claimed in claim 1, characterized in that

the delivery of the response signal (RESn) by the transponder (TRn), with which the wanted object (BKn) is fitted, triggered by the left scanning signal (INTnle) supplied to the left transmission coil (9) is detected by the left transmission coil (9) for each step of supplying the left scanning signal (INTnle) to the left transmission coil (9) with left current strengths (Ile) changed in steps, and in that

the delivery of the response signal (RESn) by the transponder (TRn), with which the wanted object (BKn) is fitted, triggered by the right scanning signal (INTnri) supplied to the right transmission coil (10) is detected by the right transmission coil (10) for each step of supplying the right scanning signal (INTnri) to the right transmission coil (10) with right current strengths (Iri) changed in steps.

7. A system (1) as claimed in claim 1, characterized in that the left scanning signal (INTnle) can be supplied to the left transmission coil (9) with a maximum left current strength (I1) by the left scanning signal generation means (12) in the first step, and in that

the right scanning signal (INTnri) can be supplied to the right transmission coil (10) with a maximum right current strength (Ii) by the right scanning signal generation means (13) in the first step.

8. A system (1) as claimed in claim 7, characterized in that

the left scanning signal (INTnle) can be supplied to the left transmission coil (9) with left current strengths (I2, . . . , Ii+1, Ii) changed in steps of substantially constant current value difference by the left scanning signal generation means (12), and in that

the value V(Ii+1) of that changed left current strength (Ii+1) of the left scanning signal (INTnle) can be determined by the left current strength value detection means (18) at which the transponder (TRn), with which the wanted object (BKn) is fitted, has changed its behavior between delivery and non-delivery of the response signal (RESn), and in that

the right scanning signal (INTnri) can be supplied to the right transmission coil (10) with right current strengths (I2, I3, . . . , Ik+1, Ik) changed in steps of substantially constant current value difference by the right scanning signal generation means (13), and in that

the value of that changed right current strength (Ik+1) of the right scanning signal (INTnri) can be determined by the right current strength value detection means (19) at which the transponder (TRn), with which the wanted object (BKn) is fitted, has changed its behavior between delivery and non-delivery of the response signal (RESn).

9. A system (1) as claimed in claim 8, characterized in that

the left scanning signal (INTnle) can be supplied to the left transmission coil (9) with reduced left current strengths (I2, . . . , Ii+1, I1, . . . , Iz) changed in steps of substantially constant current value differences by the left scanning signal generation means (12), and in that the right scanning signal (INTnri) can be supplied to the right transmission coil (10) with reduced right current strengths (I2, I3, . . . , Ik+1, Ik, . . . , Iz) in steps of substantially constant current value differences by the right scanning signal generation means (13).

10. A system (1) as claimed in claim 9, characterized in that

the left current strength value detection means (18) are constructed for determining and storing the value V(Ii+1) of that reduced left current strength (Ii+1) of the left scanning signal (INTnle) at which the transponder (TRn), with which the wanted object (BKn) is fitted, has supplied the response signal (RESn) triggered by the left scanning signal (INTnle) supplied by the left transmission coil (9) for the last time before the transponder (TRn) for the first time has not given such a response signal (RESn) any more, and in that

the right current strength value detection means (19) are constructed for determining and storing the value V(Ik+1) of that reduced right current strength (Ik+1) of the right scanning signal (INTnri) at which the transponder (TRn), with which the wanted object (BKn) is fitted, has supplied the response signal (RESn) triggered by the right scanning signal (INTnri) supplied to the right transmission coil (10) for the last time before the transponder (TRn) for the first time has not given such a response signal (RESn) any more, and in that

the position determination means (24) are constructed for determining the position (d) of the wanted object (BKn) from said value V(Ii+1) of the determined reduced left current strength (Ii+1) of the left scanning signal (INTnle) and from said value V(Ik+1) of the determined reduced right current strength (Ik+1) of the right scanning signal (INTnri).

11. A system (1) for determining the position (d) of a wanted object (BKn) which is positioned in a row (2) of objects (BK), said objects (BK) being each provided with a transponder (TR), characterized in that

a left transmission coil (9) is provided which is arranged at a left-hand end of the row (2) of objects (BK), and in that

left scanning signal generation means (12) are provided such that said left scanning signal generation means (12) can supply a left scanning signal (INTnle) for triggering a response signal (RESn) of a transponder (TRn), with which the wanted object (BKn) is fitted, in a first step to the left transmission coil (9) with a left scanning signal (Ile) having a starting value (Ii), and through which subsequently the left scanning signal (INTnle) can be supplied to the left transmission coil (9) with current strengths (I2, . . . , I1+1, Ii, . . . ,Iz) changed in steps, and through which a change in the left current strength (Ile) in accordance with a minimum current value difference is achievable, and in that

left detection means (15) are provided such that it can be ascertained whether the transponder (TRn), with which the wanted object (BKn) is fitted, has given off the response signal (RESn) triggered by the left scanning signal (INTnle) supplied to the left transmission coil (9), and in that

left current strength value detection means (18) are provided through which a value V(Ii) can be determined of that changed left current strength (Ii) of the left scanning signal (INTnle) with which after a change in the left scanning signal (INTnle) was supplied to the left transmission coil (9), and in that

a right transmission coil (10) is provided which is arranged at a right-hand end of the row (2) of objects (BK), and in that

right scanning signal generation means (13) are provided such that said right scanning signal generation means (13) can supply the right scanning signal (INTnri) for triggering the response signal (RESn) of the transponder (TRn), with which the wanted object (BKn) is fitted, in a first step to the right transmission coil (10) with a right current strength (Iri) having a starting value (Ii), and through which subsequently the right scanning signal (INTnri) can be supplied to the right transmission coil (10) with current strengths (I2, I3, . . . , Ik+1, Ik, . . . , Iz) changed in steps, and by through which a change in the right current strength (Iri) in accordance with a minimum current value difference is achievable, and in that

right detection means (16) are provided by means of which it can be ascertained whether the transponder (TRn), with which the wanted object (BKn) is fitted, has given off the response signal (RESn) triggered by the right scanning signal (INTnri) supplied to the right transmission coil (10), and in that

right current strength value detection means (19) are provided through which a value V(Ik) can be determined of that changed right current strength (Ik) of the right scanning signal (INTnri) with which after a change in the right current strength (Iri) in accordance with the minimum current value difference the right scanning signal (INTnri) was supplied to the right transmission coil (10), and in that

position determination means (24) are provided through which the position (d) of the wanted object (BKn) can be determined from the knowledge of said value V(Ii) of the determined changed left current strength (Ii) of the left scanning signal (INTnle) and from the knowledge of said value V(Ik) of the determined changed right current strength (Ik) of the right scanning signal (INTnri).