Low cost wireless (resistive) sensor based on impedance coupling/modulation using MRC

• US 9,620,283 B2
• Filed: 02/25/2015
• Issued: 04/11/2017
• Est. Priority Date: 02/27/2014
• Status: Active Grant

• Current Assignee: GM Global Technology Operations LLC (General Motors Company)
• Original Assignee: GM Global Technology Operations LLC (General Motors Company)
• Inventors: Laifenfeld, Moshe
• Primary Examiner(s): Lactaoen, Billy
• Application Number:
  US14/631,113
• Publication Number:
  US 20150243432A1
• Time in Patent Office: 776 Days
• Field of Search: 324601
• CPC Class Codes: B60L 2210/30 AC to DC converters
• CPC Class Codes: B60L 2210/40 DC to AC converters
• CPC Class Codes: B60L 2240/527 Voltage
• CPC Class Codes: B60L 2240/545 Temperature
• CPC Class Codes: B60L 2240/547 Voltage
• CPC Class Codes: B60L 2270/147 electro magnetic [EMI]
• CPC Class Codes: B60L 50/40 using propulsion power supplied by capacitors
• CPC Class Codes: B60L 53/122 Circuits or methods for driving the primary coil, e.g. supplying electric power to the coil
• CPC Class Codes: G01R 27/02 Measuring real or complex resistance, reactance, impedance, or other two-pole characteristics derived therefrom, e.g. time constant by measuring phase angle only G01R25/00
• CPC Class Codes: G01R 35/005 Calibrating; Standards or reference devices, e.g. voltage or resistance standards, "golden" references G01R33/0035, G01R35/002 take precedence
• CPC Class Codes: H01F 38/14 Inductive couplings for wireless supply or distribution of electric power using inductive coupling H02J50/10
• 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 10/72 Electric energy management in electromobility
• CPC Class Codes: Y02T 90/12 Electric charging stations
• CPC Class Codes: Y02T 90/14 Plug-in electric vehicles

Abstract

A system for transmitting data signals from a sensor on a vehicle through magnetic resonance coupling (MRC). The system includes a control circuit having a base coil, a variable current source, a variable capacitor and a control load, where the variable current source and the capacitor are tuned to provide a predetermined AC current to the base coil so as to generate an oscillating magnetic field at a predetermined frequency. The system also includes a receiver circuit associated with the sensor, where the receiver circuit includes a receiver coil, a tuning capacitor and a variable resistive load. The receiver coil is tuned and magnetically coupled to the base coil at the predetermined frequency. A change in the variable resistive load in the receiver circuit in response to a sensor measurement causes a change in the voltage across the control load that gives an indication of the sensor measurement.

Claims

1. A magnetic resonance coupling (MRC) circuit comprising:

a control circuit including a base coil, a variable current source, a variable tuning capacitor and a control load, said variable current source selectively providing a predetermined current to the base coil so as to generate an oscillating magnetic field at a predetermined frequency; and

at least one receiver circuit including a receiver coil, a tuning capacitor and a sensor that measures an environmental condition, said receiver coil being tuned to a resonant frequency that causes it to be magnetically coupled to the base coil at the predetermined frequency, wherein sensor measurements provided by the sensor in the at least one receiver circuit cause a change in the magnetic coupling between the base coil and the receiver coil that causes a change in the voltage across the control load.

2. The MRC circuit according to claim 1 wherein the at least one receiver circuit is a plurality of receiver circuits each being tuned to a separate resonant frequency, said control circuit changing the predetermined frequency to be tuned to a particular receiver coil to communicate with that receiver circuit.

3. The MRC circuit according to claim 1 wherein the at least one receiver circuit includes a microcontroller and a complex load ladder including a plurality of complex loads, said sensor providing a measurement signal to the microcontroller and said microcontroller selectively switching in one or more of the complex loads into the receiver circuit as determined by the measurement signal.

4. The MRC circuit according to claim 3 wherein the microcontroller includes a table that stores complex load values for different measurement signals.

5. The MRC circuit according to claim 3 wherein the microcontroller selectively switches a predetermined sequence of the complex loads as a reference load.

6. The MRC circuit according to claim 1 wherein the sensor is a variable resistive load, and wherein the measurement of the environmental condition directly causes a change in the magnetic coupling.

7. The MRC circuit according to claim 6 wherein the sensor includes a calibration resistor having a known resistance provided for calibration purposes, said calibration resistor being selectively switched into the receiver circuit.

8. The MRC circuit according to claim 1 wherein the control circuit and the receiver circuit are on a vehicle.

9. The MRC circuit according to claim 1 wherein the sensor is a pressure, temperature or strain sensor.

10. A magnetic resonance coupling (MRC) circuit for providing data transfer from a sensor on a vehicle to a controller, said MRC circuit comprising:

a control circuit on the vehicle including the controller, a base coil, a variable current source, a tuning capacitor and a control load, said variable current source providing a predetermined current to the base coil so as to generate an oscillating magnetic field at a predetermined frequency; and

at least one receiver circuit on the vehicle including the sensor, a receiver coil, a tuning capacitor, a complex load ladder including a plurality of complex loads and a microcontroller, said receiver coil being tuned to a resonant frequency, said receiver coil being magnetically coupled to the base coil at the predetermined frequency, said sensor providing a measurement signal to the microcontroller and said microcontroller selectively switching in one or more of the complex loads into the receiver circuit as determined by the measurement signal, wherein a change in the complex load in the receiver circuit causes a change in the magnetic coupling between the base coil and the receiver coil that causes a change in the voltage across the control load.

11. The MRC circuit according to claim 10 wherein the at least one receiver circuit is a plurality of receiver circuits each being tuned to a separate resonant frequency, said control circuit changing the predetermined frequency to be tuned to a particular receiver coil to communicate with that receiver circuit.

12. The MRC circuit according to claim 10 wherein the microcontroller includes a table that stores complex load values for different measurement signals.

13. The MRC circuit according to claim 10 wherein the microcontroller selectively switches a predetermined sequence of the complex loads as a reference load.

14. The MRC circuit according to claim 10 wherein the sensor is a resistive sensor, said sensor including a calibration resistor having a known resistance provided for calibration purposes, said calibration resistor being selectively switched into the receiver circuit.

15. The MRC circuit according to claim 10 wherein the sensor is a pressure, temperature or strain sensor.

16. A magnetic resonance coupling (MRC) circuit for providing data transfer from a resistive sensor on a vehicle measuring an environmental condition to a controller, said MRC circuit comprising:

a control circuit on the vehicle including the controller, a base coil, a variable current source, a tuning capacitor and a control load, said variable current source providing a predetermined current to the base coil so as to generate an oscillating magnetic field at a predetermined frequency; and

at least one receiver circuit on the vehicle including the sensor, a receiver coil and a tuning capacitor, said receiver coil being magnetically coupled to the base coil at the predetermined frequency, said sensor including the variable resistive load, where the measurement of the environmental condition directly causes a change in the magnetic coupling between the base coil and the receiver coil that causes a change in voltage across the control load that is read by the controller.

17. The MRC circuit according to claim 16 wherein the at least one receiver circuit is a plurality of receiver circuits each being tuned to a separate resonant frequency, said control circuit changing the predetermined frequency to be tuned to a particular receiver coil to communicate with that receiver circuit.

18. The MRC circuit according to claim 16 wherein the at least one receiver circuit includes a microcontroller and a complex load ladder including a plurality of complex loads, said sensor providing a measurement signal to the microcontroller and said microcontroller selectively switching in one or more of the complex loads into the receiver circuit as determined by the measurement signal.

19. The MRC circuit according to claim 16 wherein the sensor includes a calibration resistor having a known resistance provided for calibration purposes, said calibration resistor being selectively switched into the receiver coil.

20. The MRC circuit according to claim 16 wherein the sensor is a pressure, temperature or strain sensor.