Method and System for Determining Locations of Smartkeys

• US 20140292581A1
• Filed: 03/27/2013
• Published: 10/02/2014
• Est. Priority Date: 03/27/2013
• Status: Abandoned Application

• Current Assignee: Mitsubishi Electric Research Laboratories, Inc. (Mitsubishi Electric Corporation)
• Original Assignee: Mitsubishi Electric Research Laboratories, Inc. (Mitsubishi Electric Corporation)
• Inventors: Orlik, Philip, Seran, Santosh
• Application Number:
  US13/851,170
• Publication Number:
  US 20140292581A1
• Time in Patent Office: Days
• US Class Current: 342/417
• CPC Class Codes: G01S 5/06 Position of source determined by co-ordinating a plurality of position lines defined by path-difference measurements G01S5/12 takes precedence

Abstract

A location of a smartkey is determined by first determining coordinates of a set of candidate vertices of an array of receive antennas at a receiver based on maximal magnetic field voltages in the receive antennas due transmitting a radio signal (RF) by the smartkey. A set of candidate locations of the transmitter is determined based on the coordinate of the set of vertices. A set of final candidate locations is determined based on a predetermined threshold of the voltages. The final candidate locations are then combined to determine the location of the smartkey.

Claims

1. A method for determining a location of a smartkey, comprising the steps:

determining coordinates of a set of candidate vertices of an array of receive antennas at a receiver based on maximal magnetic field voltages in the receive antennas due transmitting a radio signal (RF) by the smartkey;

determining a set of candidate locations of the transmitter based on the coordinate of the set of vertices;

determining a set of final candidate locations based on a predetermined threshold of the voltages; and

combining the final candidate locations to determine the location of the smartkey, wherein the steps are performed in a processor.

2. The method of claim 1, wherein a transmit antenna of the smartkey is directional.

3. The method of claim 1, wherein the frequency is about less than 200 kHz.

4. The method of claim 1, wherein a three-dimensional geometry of the array of antennas is known at the receiver.

5. The method of claim 1, wherein the array of antennas is arranged in a vehicle.

6. The method. of claim 4, wherein the geometry is triangular.

7. The method of claim 2, wherein all the antennas are resonant with each other.

8. The method of claim 2, wherein the transmit antenna is a coil with a capacitance in parallel with the coil.

9. The method of claim of claim 1, further comprising:

generating a control signal by the receiver is based on the location.

10. The method of claim 1, wherein the determining of the coordinates is based on the tolerance.

11. The method of claim 5, wherein the set of candidate locations is based on the triangular geometry.

12. The method of claim 1, wherein the combining is based on an average of the locations.

13. A system for determining a location of a smartkey, comprising:

a receiver including an array of receive antennas; and

a processor configured to determine coordinates of a set of candidate vertices of an array of receive antennas at the receiver based on maximal magnetic field voltages in the receive antennas due transmitting a radio signal (RF) by the smartkey, and to determine a set of candidate location of the transmitter based on the coordinate of the set of vertices; and

to determine a set of final candidate a locations based on a predetermined threshold of the voltages, and to combine the final candidate locations to determine the location of the smartkey.