Dual data encoding in a pulse width modulation signal

Patent metadata

Field	Value
Publication number	US-12429586-B2
Application number	US-202218059831-A
Country	US
Kind code	B2
Filing date	Nov 29, 2022
Priority date	Nov 29, 2022
Publication date	Sep 30, 2025
Grant date	Sep 30, 2025

Abstract

Methods and systems are provided for encoding position and temperature in a pulse width modulation (PWM) signal. The method includes acquiring a PWM signal from an eddy current sensor, and determining the temperature of the eddy current sensor based on a PWM signal feature. The PWM signal feature is a PWM frequency and/or a PWM logic level.

First claim

The invention claimed is:

1. A method for sensing temperature, comprising:
acquiring a pulse width modulation (PWM) signal from a single coil of an eddy current sensor;
determining a temperature of the eddy current sensor based on a frequency of the PWM signal, wherein the frequency is equal to a reciprocal of a cycle of the PWM signal; and
determining a position of a target object based on a percentage of a duty cycle of the PWM signal.

2. The method of claim 1 , wherein the temperature of the eddy current sensor is approximately equal to a temperature of the target object.

3. The method of claim 1 , further comprising activating an actuator in response to the determined temperature.

4. The method of claim 1 , wherein the eddy current sensor and the target object are included in a vehicle.

5. The method of claim 1 , further comprising determining the position of the target object based on a duty cycle of the PWM signal.

6. The method of claim 1 , wherein a PWM logic level includes a high logic level and/or a low logic level, the method further comprising determining the temperature based on the PWM logic level.

7. An eddy current sensor, comprising:
a semiconductor circuit configured to measure an eddy current voltage and a temperature dependent voltage; and
a microcontroller including instructions stored in non-transitory memory that, when executed, cause the microcontroller to:
receive an eddy current voltage signal and a temperature signal,
correct the eddy current voltage signal based on the temperature signal,
encode the corrected eddy current voltage signal in a duty cycle of a pulse width modulation (PWM) signal,
encode the temperature signal in a frequency or a logic level of the PWM signal, wherein the frequency is equal to a reciprocal of a cycle of the PWM signal and a position of a target object based on a percentage of a duty cycle of the PWM signal, and
output the PWM signal to a controller.

8. The eddy current sensor of claim 7 , wherein the eddy current voltage is based on the position of the target object within a magnetic field generated by the eddy current sensor.

9. The eddy current sensor of claim 7 , wherein the temperature signal is based on the temperature of the eddy current sensor.

10. The eddy current sensor of claim 9 , wherein the temperature signal is approximately equal to the target object sensed by the eddy current sensor.

11. The eddy current sensor of claim 7 , wherein the logic level of the PWM signal includes a high logic level and/or a low logic level.

12. The eddy current sensor of claim 7 , wherein the temperature signal is encoded in the frequency or the logic level of the PWM signal in response to a resolution and/or an update speed of the temperature signal.

13. A system, comprising:
a target object;
an eddy current sensor comprising only one coil and configured to sense a position and temperature of the target object and output the position and temperature of the target object encoded into a pulse width modulation (PWM) signal, the position based on a frequency of the PWM signal, wherein the frequency is equal to a reciprocal of a cycle of the PWM signal and a position of the target object based on a percentage of a duty cycle of the PWM signal; and
a controller configured to receive the PWM signal and, in response to the PWM signal, activate an actuator.

14. The system of claim 13 , wherein the target object includes a first target object and a second target object.

15. The system of claim 14 , wherein the temperature of the first target object is encoded into a first feature of the PWM signal and the temperature of the second target object is encoded into a second feature of the PWM signal.

16. The system of claim 13 , wherein the position of the target object is based on a signal generated by a semiconductor circuit of the eddy current sensor and the temperature is based on a signal generated by a temperature sensor of the eddy current sensor.

17. The system of claim 13 , wherein the position is encoded into a duty cycle of the PWM signal.

18. The system of claim 13 , wherein the temperature is encoded into a frequency of the PWM signal or a logic level of the PWM signal.

Assignees

• Dana Automotive Systems Group

Inventors

• Paielli Perry M

Classifications

• G01S17/26 Primary

  wherein the transmitted pulses use a frequency-modulated or phase-modulated carrier wave, e.g. for pulse compression of received signals · CPC title

• G01S17/14 Primary

  wherein a voltage or current pulse is initiated and terminated in accordance with the pulse transmission and echo reception respectively, e.g. using counters · CPC title

• G01B21/045

  Correction of measurements (G01B9/02055 takes precedence) · CPC title

• G01B7/003

  for measuring position, not involving coordinate determination (coordinate measuring G01B7/004) · CPC title

• G01K13/00

  Thermometers specially adapted for specific purposes · CPC title