Sensor system and a method of temperature-compensation thereof

Patent metadata

Field	Value
Publication number	US-12429359-B2
Application number	US-201917595309-A
Country	US
Kind code	B2
Filing date	May 15, 2019
Priority date	May 15, 2019
Publication date	Sep 30, 2025
Grant date	Sep 30, 2025

Abstract

A sensor system includes a first sensor, a second sensor, and a control in electrical communication with the first and second sensors. The controller includes a memory for storing data configured to store an offset profile for the at least one output of the first sensor. The offset profile includes a plurality of offset values, which is calculated using measured outputs of the first sensor determined while a position of a conductive material is maintained and a temperature of surrounding atmosphere is varied.

First claim

What is claimed is:

1. A sensor system, comprising:
a first sensor positioned radially outward from a sensor plate coupled to a lock ring of a differential of an axle assembly of a drive unit, the first sensor configured to generate at least one output, wherein the first sensor is an eddy current sensor, further comprising a second sensor positioned opposite the first sensor relative to the sensor plate, wherein the first sensor and the second sensor are positioned within the differential, and wherein the second sensor is a temperature sensor; and
a controller in electrical communication with the first sensor, the controller comprising a memory for storing data configured to store at least one offset value for the at least one output of the first sensor based on a temperature sensed by the second sensor.

2. The sensor system of claim 1 , wherein the at least one output of the first sensor is indicative of a distance of a conductive material from the first sensor, wherein the differential comprises a differential case coupled to a ring gear, the ring gear meshed with a pinion gear coupled to a transfer case.

3. The sensor system of claim 1 , wherein the at least one output of the first sensor is a frequency signal, wherein a ring gear is integrally formed with a differential case of the differential.

4. The sensor system of claim 1 , wherein at least one offset value is a difference between at least one measured output of the first sensor and a predetermined output of the first sensor.

5. The sensor system of claim 4 , wherein the at least one measured output of the first sensor is determined while a position of a conductive material is maintained and a temperature of surrounding atmosphere is varied.

6. The sensor system of claim 4 , wherein the predetermined output of the first sensor is a frequency signal at an ideal ambient temperature.

7. The sensor system of claim 1 , wherein the second sensor is in electrical communication with the controller, wherein the second sensor is configured to measure a temperature of a desired input location, wherein the differential comprises a differential case, the differential case comprising a ring gear flange coupled to a ring gear.

8. The sensor system of claim 7 , wherein the second sensor is a thermistor, wherein the sensor plate is located outside of the differential case and wherein sensor plate tabs extend into the differential case.

9. A method of temperature-compensation of a sensor system, comprising the steps of:
providing a first sensor configured to generate an output, the first sensor positioned radially outward from a sensor plate coupled to a lock ring of a differential of an axle assembly of a drive unit of a vehicle, wherein the first sensor is an eddy current sensor, further comprising a second sensor positioned opposite the first sensor relative to the sensor plate, wherein the second sensor is a temperature sensor, and wherein the first sensor and the second sensor are positioned within the differential;
providing a controller in electrical communication with the first sensor, wherein the controller comprises a memory for storing data;
providing a plurality of offset values for the output of the first sensor;
transmitting the output of the first sensor to the controller; and
calculating a temperature-compensated output of the first sensor, based on an output of the second sensor, by adjusting the output of the first sensor by one of the offset values stored in the memory of the controller.

10. The method of claim 9 , further comprising the step of providing the second sensor in electrical communication with the controller, wherein the second sensor is configured to measure a temperature of a desired input location, wherein the first sensor and the second sensor are located the same distance from an axis of rotation of the differential.

11. The method of claim 10 , wherein the one of the offset values is obtained based upon the output of the first sensor and the measured temperature from the second sensor.

12. The method of claim 9 , further comprising the step of comparing the temperature-compensated output of the first sensor to calibrated values the output of the first sensor to determine a state of the differential of the vehicle, wherein the first sensor is located radially above the sensor plate and the second sensor is located radially below the sensor plate.

13. The method of claim 9 , wherein the offset values are calculated using measured outputs of the first sensor determined while a position of a conductive material is maintained and a temperature of surrounding atmosphere is varied, wherein the first sensor is located axially adjacent to an inboard surface of the sensor plate and the second sensor is located axially adjacent to an outboard surface of the sensor plate.

14. The method of claim 13 , wherein each of the offset values is a difference between one of the measured outputs of the first sensor and a predetermined output of the first sensor, wherein the inboard surface and the outboard surface of the sensor plate are parallel to inboard and outboard surfaces of a differential housing and transverse to an axis of rotation of the differential.

Assignees

• Dana Automotive Systems Group

Inventors

• Davis Justin S

Classifications

• G01D5/2013

  by a movable ferromagnetic element, e.g. a core (G01D5/2033 takes precedence) · CPC title

• G01D3/0365 Primary

  the undesired influence being measured using a separate sensor, which produces an influence related signal · CPC title