Real-time virtual axle assembly temperature sensor

• US 9,714,871 B2
• Filed: 05/20/2014
• Issued: 07/25/2017
• Est. Priority Date: 05/20/2014
• Status: Active Grant

• Current Assignee: FCA US LLC (Stellantis NV)
• Original Assignee: FCA US LLC (Stellantis NV)
• Inventors: Hegde, Prashant, Brown, Samuel G, Chen, Gang, Richardson, Roland T
• Primary Examiner(s): Jagan, Mirellys
• Application Number:
  US14/282,341
• Publication Number:
  US 20150338287A1
• Time in Patent Office: 1,162 Days
• Field of Search: 374134, 374144, 374141
• CPC Class Codes: B61K 9/06 by detecting or indicating heat radiation from overheated axles
• CPC Class Codes: G01K 13/00 Thermometers specially adapted for specific purposes
• CPC Class Codes: G01K 13/08 in rotary movement

Abstract

Techniques for real-time virtual sensing of an axle assembly temperature include determining, at a controller of a vehicle, an initial temperature of an axle assembly of the vehicle based on an ambient temperature and a fluid temperature of a transmission. The techniques include determining, at the controller, an operating mode of the vehicle, the operating mode of the vehicle being one of moving and non-moving. The techniques also include estimating, at the controller, a temperature of the axle assembly based on the initial axle assembly temperature and the vehicle operating mode using an axle temperature model.

Claims

1. A vehicle, comprising:

an axle assembly, including;

an input configured to receive drive torque from a powertrain of the vehicle,

a pair of axle shafts,

a gearbox that translates the drive torque from the input to the pair of axle shafts, and

an axle housing having an axle shaft portion that houses at least a portion of the pair of axle shafts and a gearbox housing portion that houses the gearbox; and

a controller configured to;

(i) determine an initial temperature of the axle assembly based on an ambient temperature external to the vehicle and a fluid temperature of a transmission of the vehicle,

(ii) determine an operating mode of the vehicle, the operating mode of the vehicle being one of moving and non-moving, and

(iii) estimate, using an axle temperature model, a temperature of the axle assembly based on the determined initial axle assembly temperature and the vehicle operating mode.

2. The vehicle of claim 1, wherein:

the input includes a pinion shaft having a pinion gear fixed thereto; and

the gearbox includes the pinion gear and a differential assembly, the differential assembly having a ring gear in meshing engagement with the pinion gear and a differential gear set coupled to the pair of axle shafts.

3. The vehicle of claim 1, wherein the controller is configured to estimate the temperature of the axle assembly based on (i) a rotational speed of the powertrain, (ii) a speed of the vehicle, (iii) a rotational speed of the axle shafts, and (iv) a drive torque at the axle shafts.

4. The vehicle of claim 1, wherein the controller is configured to determine the initial temperature of the axle assembly based on a time since a key-off event of the vehicle.

5. The vehicle of claim 1, wherein the controller is further configured to perform torque management of the powertrain based on the estimated axle assembly temperature.

6. The vehicle of claim 1, wherein the controller is further configured to perform speed limiting of the vehicle based on the estimated axle assembly temperature.

7. The vehicle of claim 1, wherein, based on the estimated axle assembly temperature, the controller is further configured to at least one of:

set a diagnostic trouble code (DTC);

enable a malfunction indicator lamp (MIL); and

output an axle assembly lubricant change indicator.

8. The vehicle of claim 1, wherein the axle temperature model comprises a lumped system model based on a difference between (i) heat generated by the gearbox, and (ii) heat lost to an environment via the gearbox housing portion and the axle shaft housing portion.

9. The vehicle of claim 8, wherein the heat lost to the environment via the gearbox housing portion and the axle shaft housing portion is determined based on a natural convection heat transfer model when the vehicle is non-moving.

10. The vehicle of claim 8, wherein the heat lost to the environment via the gearbox housing portion and the axle shaft housing portion is determined based on a forced convection heat transfer model when the vehicle is moving.

11. A method for estimating an axle assembly temperature, comprising:

determining, at a controller of a vehicle, an initial temperature of an axle assembly of the vehicle based on an ambient temperature external to the vehicle and a fluid temperature of a transmission of the vehicle;

determining, at the controller, an operating mode of the vehicle, the operating mode being one of moving and non-moving; and

estimating, at the controller, a temperature of the axle assembly based on the initial axle assembly temperature and the vehicle operating mode using an axle temperature model.

12. The method of claim 11, wherein determining, at the controller, the initial temperature of the axle assembly is further based on a time since a key-off event of the vehicle.

13. The method of claim 11, further comprising performing, by the controller, torque management of a powerplant of the vehicle, the transmission, or a combination thereof based on the estimated axle assembly temperature.

14. The method of claim 11, further comprising performing, by the controller, speed limiting of the vehicle based on the estimated axle assembly temperature.

15. The method of claim 11, wherein estimating, at the controller, the temperature of the axle assembly based on the initial axle assembly temperature and the vehicle operating mode using the axle temperature model includes estimating, at the controller, a temperature of the axle assembly based on the initial axle assembly temperature and the vehicle operating mode using the axle temperature model in an absence of an axle temperature sensor associated with the axle assembly.

16. The method of claim 11, wherein:

the axle temperature model comprises a lumped system model based on a difference between (i) heat generated by a gearbox of the axle assembly and (ii) heat lost to an environment via a gearbox housing portion of the axle assembly and an axle shaft housing portion of the axle assembly; and

the axle shaft housing portion houses a pair of axle shafts of the axle assembly, and the gearbox housing portion houses a gearbox that is configured to translate drive torque from an input of the axle assembly to the pair of axle shafts.

17. The method of claim 16, wherein the heat lost to the environment via the gearbox housing portion and the axle shaft housing portion is determined based on a natural convection heat transfer model when the vehicle is non-moving.

18. The method of claim 16, wherein the heat lost to the environment via the gearbox housing portion and the axle shaft housing portion is determined based on a forced convection heat transfer model when the vehicle is moving.

19. The method of claim 16, wherein estimating, at the controller, the axle assembly temperature is further based on (i) a rotational speed of a powertrain of the vehicle, (ii) a speed of the vehicle, (iii) a rotational speed of the axle shafts, and (iv) a drive torque at the axle shafts.

20. A system for a vehicle, the system comprising:

a transmission fluid temperature sensor configured to measure a temperature of a fluid in a transmission of the vehicle; and

a controller configured to;

determine an initial temperature of an axle assembly of the vehicle based on an ambient temperature external to the vehicle and the measured transmission fluid temperature;

determine an operating mode of the vehicle, the operating mode being one of moving and non-moving; and

estimate a temperature of the axle assembly based on the initial axle assembly temperature and the vehicle operating mode using an axle temperature model.