Position finding system

• US 8,903,548 B2
• Filed: 12/15/2011
• Issued: 12/02/2014
• Est. Priority Date: 12/16/2010
• Status: Active Grant

• Current Assignee: Pepperl + Fuchs GmbH
• Original Assignee: Pepperl + Fuchs GmbH
• Inventors: Galm, Timo, Freund, Thomas
• Primary Examiner(s): Tarcza, Thomas
• Assistant Examiner(s): GOLDMAN, RICHARD A
• Application Number:
  US13/327,278
• Publication Number:
  US 20120153089A1
• Time in Patent Office: 1,083 Days
• Field of Search: None
• US Class Current: 700/245
• CPC Class Codes: B61L 25/025 Absolute localisation, e.g. providing geodetic coordinates
• CPC Class Codes: B61L 3/125 using short-range radio transmission
• CPC Class Codes: G05D 1/0265 using buried wires
• CPC Class Codes: G05D 1/028 using a RF signal

Abstract

Position finding system having a sensor unit and a transmitter unit. The sensor unit comprises a first RFID transponder reader unit, a first inductive detector unit, and an analysis unit connected to the RFID transponder reader unit and the inductive detector unit; the transmitter unit comprises an RFID transponder and a metallic material. The sensor unit is movable relative to the transmitter unit. The RFID transponder reader unit is configured for absolute position finding and outputs a first position value, and the inductive detector unit is configured for absolute position finding and outputs a second position value. The analysis unit is configured to determine, from the data acquired from the transmitter unit, an absolute position of the sensor unit from the first and second position values.

Claims

1. A position finding system comprising:

a sensor unit having a first RFID transponder reader unit, a first inductive detector unit, and an analysis unit connectable to the first RFID transponder reader unit and the first inductive detector unit; and

a transmitter unit having an RFID transponder and a component transmitter unit that is made of a metallic material, the sensor unit being configured to be movable relative to the transmitter unit,

wherein the first RFID transponder reader unit is set up for absolute position determination and outputs a first position value,

wherein the first inductive detector unit is set up for absolute position determination and outputs a second position value,

wherein the analysis unit is configured to determine, from data acquired from the transmitter unit, an absolute position of the sensor unit relative to the transmitter unit based on the first and second position values, and

wherein the analysis unit is configured to determine a coarse resolution of the absolute position using the first position value and subsequently a fine resolution of the absolute position using the second position value based on a change in induction of the component transmitter unit detected by the first inductive detector unit, and

wherein the fine resolution is more refined than the coarse resolution.

2. The position finding system according to claim 1, wherein the analysis unit is configured to determine the absolute position from the first position value currently output and the second position value currently output.

3. The position finding system according to claim 1, wherein the first RFID transponder reader unit and the first inductive detector unit are arranged along a line that extends in the same direction as the direction in which a longitudinal axis of the transmitter unit extends.

4. The position finding system according to claim 1, wherein the sensor unit additionally includes a second RFID transponder reader unit.

5. The position finding system according to claim 1, wherein the transmitter unit comprises a plurality of transmitter units, the plurality of transmitter units are arranged in a row, and the RFID transponders and component transmitter units made of a metallic material are arranged in an alternating manner.

6. The position finding system according to claim 5, wherein at least one component transmitter unit made of a metallic material is arranged between two RFID transponders.

7. The position finding system according to claim 1, wherein the transmitter unit is constructed on a flexible carrier material.

8. The position finding system according to claim 7, wherein the flexible carrier material is a tape and is configured to be unrolled from a roll.

9. The position finding system according to claim 7, wherein the flexible carrier material is arranged on a rail, wherein an RFID transponder is placed at a start and at an end of the rail.

10. The position finding system according to claim 1, wherein the sensor unit is located on a rail vehicle.

11. The position finding system according to claim 1, wherein the absolute position is determined along a guide device of a guided vehicle or a rail vehicle.

12. A method for determining an absolute position, the method comprising:

providing a sensor unit having at least one RFID transponder reader unit, an inductive detector unit, and an analysis unit connectable to the RFID transponder reader unit and the inductive detector unit;

providing a plurality of transmitter units each having an RFID transponder and a component transmitter unit made of a metallic material, the plurality of transmitter units being arranged in a row;

outputting a first position value by the RFID transponder reader unit of one of the plurality of transmitter units for absolute position finding;

detecting a change in induction of the component transmitter unit using the first inductive detector unit;

outputting a second position value based on the detected change in induction of the component transmitter unit for absolute position finding; and

determining an absolute position of the sensor unit relative to the one of the plurality of transmitter units via the analysis unit from position values acquired from the transmitter unit based on the first and second position values,

wherein a coarse resolution of the absolute position is determined by the analysis unit using the first position value and a fine resolution of the absolute position is subsequently determined by the analysis unit using the second position value, and

wherein the fine resolution is more refined than the coarse resolution.

13. The method for determining the absolute position according to claim 12, wherein the absolute position is determined by the analysis unit from the first position value currently output and the second position value currently output.