Systems, methods and apparatuses for guidance and alignment in electric vehicles wireless inductive charging systems

• US 10,340,752 B2
• Filed: 03/14/2016
• Issued: 07/02/2019
• Est. Priority Date: 06/23/2015
• Status: Active Grant

• Current Assignee: WiTricity Corporation
• Original Assignee: WiTricity Corporation
• Inventors: Widmer, Hans Peter, Daetwyler, Andreas, Sieber, Lukas
• Primary Examiner(s): Hoque, Farhana A
• Application Number:
  US15/069,559
• Publication Number:
  US 20160380487A1
• Time in Patent Office: 1,205 Days
• Field of Search: 324654, 307104
• CPC Class Codes: B60L 53/126 Methods for pairing a vehicle and a charging station, e.g. establishing a one-to-one relation between a wireless power transmitter and a wireless power receiver
• CPC Class Codes: B60L 53/36 by positioning the vehicle
• CPC Class Codes: B60L 53/38 specially adapted for charging by inductive energy transfer
• CPC Class Codes: B60L 53/39 with position-responsive activation of primary coils
• CPC Class Codes: G01D 5/20 by varying inductance, e.g. by a movable armature
• CPC Class Codes: G01D 5/2066 by movement of a single coil with respect to a single other coil
• CPC Class Codes: G01R 33/02 Measuring direction or magnitude of magnetic fields or magnetic flux G01R33/20 takes precedence
• CPC Class Codes: G01R 33/0206 Three-component magnetometers
• CPC Class Codes: H01F 2038/143 for signals
• CPC Class Codes: H01F 38/14 Inductive couplings for wireless supply or distribution of electric power using inductive coupling H02J50/10
• CPC Class Codes: H02J 50/12 of the resonant type
• CPC Class Codes: H02J 50/90 involving detection or optimisation of position, e.g. alignment
• CPC Class Codes: H04B 5/263 Multiple coils at either side
• CPC Class Codes: H04B 5/266 One coil at each side, e.g. with primary and secondary coils
• CPC Class Codes: H04B 5/73 for taking measurements, e.g. using sensing coils
• CPC Class Codes: H04B 5/79 for data transfer in combination with power transfer
• CPC Class Codes: Y02T 10/70 Energy storage systems for electromobility, e.g. batteries
• CPC Class Codes: Y02T 10/7072 Electromobility specific charging systems or methods for batteries, ultracapacitors, supercapacitors or double-layer capacitors
• CPC Class Codes: Y02T 90/12 Electric charging stations
• CPC Class Codes: Y02T 90/14 Plug-in electric vehicles

Abstract

An apparatus for determining a relative position of a wireless power transmitter from a wireless power receiver is provided. The apparatus comprises a plurality of sense coils, each configured to generate a respective voltage signal under influence of a first alternating magnetic field oscillating at two frequencies and a second alternating magnetic field oscillating at at least one frequency. The apparatus further comprises a processor configured to determine the relative position of the wireless power transmitter from the wireless power receiver based on the respective voltage signal from each of the plurality of sense coils.

Claims

1. An apparatus for determining a relative position of a wireless power transmitter from a wireless power receiver, comprising:

a plurality of sense coils, each configured to generate a respective voltage signal under influence of at least a first alternating magnetic field oscillating at two frequencies concurrently and a second alternating magnetic field oscillating at at least one frequency concurrently with the first alternating magnetic field; and

a processor configured to determine the relative position of the wireless power transmitter from the wireless power receiver based on the respective voltage signal from each of the plurality of sense coils, wherein the voltage signal generated by each of the plurality of sense coils comprises at least;

a first portion caused by the first alternating magnetic field oscillating at a first of the two frequencies,

a second portion caused by the first alternating magnetic field oscillating at a second of the two frequencies, and

a third portion caused by the second alternating magnetic field oscillating at the at least one frequency, and

wherein the processor is configured to estimate a relative phase angle between the first portion and the second portion.

2. The apparatus of claim 1, wherein the plurality of sense coils comprise at least a first sense coil and a second sense coil oriented orthogonal to one another to provide at least a two-axis sensor.

3. The apparatus of claim 1, wherein the plurality of sense coils comprise at least three co-planar sense coils configured to provide at least a two-axis sensor in combination.

4. The apparatus of claim 1, wherein processor is configured to establish relative phase synchronization in the time domain between the first portion, the second portion, and the third portion by shifting a detection time instant by an amount that is a function of the relative phase angle and a predetermined frequency separation between the at least one frequency of the second alternating magnetic field and at least one of the two frequencies of the first alternating magnetic field.

5. The apparatus of claim 1, wherein the processor is further configured to establish relative phase synchronization in the frequency domain between the first portion, the second portion, and the third portion by shifting a phase angle of at least one of the first portion, the second portion and the third portion by an angle corresponding to the relative phase angle or an integer multiple of the relative phase angle.

6. The apparatus of claim 1, wherein the processor is configured to establish relative phase synchronization between the first portion, the second portion, and the third portion by using a synchronization sequence that is transmitted in at least one of the first alternating magnetic field and the second alternating magnetic field.

7. The apparatus of claim 1, wherein the processor is further configured to identify a source of the first alternating magnetic field or the second alternating magnetic field based on a synchronization sequence that is transmitted in at least one of the first alternating magnetic field and the second alternating magnetic field.

8. A method for determining a relative position of a wireless power transmitter from a wireless power receiver, comprising:

generating a respective voltage signal by each of a plurality of sense coils under influence of a first alternating magnetic field oscillating at two frequencies concurrently and a second alternating magnetic field oscillating at at least one frequency concurrently with the first alternating magnetic field;

determining the relative position of the wireless power transmitter from the wireless power receiver based on the respective voltage signal generated by each of the plurality of sense coils, wherein the voltage signal generated by each of the plurality of sense coils comprises at least;

first portion caused by the first alternating magnetic field oscillating at a first of the two frequencies,

a second portion caused by the first alternating magnetic field oscillating at a second of the two frequencies, and

a third portion caused by the second alternating magnetic field oscillating at the at least one frequency; and

estimating a relative phase angle between the first portion and the second portion.

9. The method of claim 8, wherein the plurality of sense coils comprise at least a first sense coil and a second sense coil oriented orthogonal to one another to provide at least a two-axis sensor.

10. The method of claim 8, wherein the plurality of sense coils comprise at least three co-planar sense coils configured to provide at least a two-axis sensor in combination.

11. The method of claim 8, further comprising establishing relative phase synchronization in the time domain between the first portion, the second portion, and the third portion by shifting a detection time instant by an amount that is a function of the relative phase angle and a predetermined frequency separation between the at least one frequency of the second alternating magnetic field and at least one of the two frequencies of the first alternating magnetic field.

12. The method of claim 8, further comprising establishing relative phase synchronization in the frequency domain between the first portion, the second portion, and the third portion by shifting a phase angle of at least one of the first portion, the second portion and the third portion by an angle corresponding to the relative phase angle or an integer multiple of the relative phase angle.

13. The method of claim 8, further comprising establishing relative phase synchronization between the first portion, the second portion and the third portion by using a synchronization sequence that is transmitted in at least one alternating magnetic field.

14. The method of claim 8, further comprising identifying a source of the first alternating magnetic field or the second alternating magnetic based on a synchronization sequence that is transmitted in at least one alternating magnetic field.