Tire suspension fusion system for estimation of tire deflection and tire load

• US 9,874,496 B2
• Filed: 03/12/2013
• Issued: 01/23/2018
• Est. Priority Date: 03/12/2013
• Status: Active Grant

• Current Assignee: Goodyear Tire & Rubber Company
• Original Assignee: Goodyear Tire & Rubber Company
• Inventors: Singh, Kanwar Bharat
• Primary Examiner(s): Macchiarolo, Peter
• Assistant Examiner(s): Roberts, Herbert K
• Application Number:
  US13/795,761
• Publication Number:
  US 20140260585A1
• Time in Patent Office: 1,778 Days
• CPC Class Codes: B60C 23/0488 Movement sensor, e.g. for sensing angular speed, acceleration or centripetal force
• CPC Class Codes: B60C 23/064 comprising tyre mounted deformation sensors, e.g. to determine road contact area
• CPC Class Codes: B60C 23/065 by monitoring vibrations in tyres or suspensions B60C23/062 takes precedence
• CPC Class Codes: G01M 17/02 Tyres

Abstract

A system and method estimating a vehicle tire load includes a tire static load estimator estimating a static tire load using a tire attached TPMS sensor; a Kalman filter based tire deflection estimator estimating tire vertical deflection; a load variation estimator estimating the instantaneous load variation by using the tire vertical deflection information; and an output tire load estimator calculating an output load estimation mathematically by fusing the static tire load with the instantaneous load variation information. The tire deflection estimator includes a chassis accelerometer measuring a chassis vertical acceleration; and a hub accelerometer measuring a wheel hub vertical acceleration of the tire. A linear filter model receives as inputs the chassis vertical acceleration and the wheel hub vertical acceleration.

Claims

1. A tire load estimation system for a vehicle comprising:

at least one tire mounted to a wheel hub and supporting a vehicle chassis;

at least one tire static load sensor mounted to the at least one tire for detecting a measured static tire load;

a tire static load estimator for calculating an estimated tire static load on the at least one tire based on the measured static tire load;

at least one vehicle chassis-mounted sensor for measuring a vehicle chassis vertical deflection;

a tire deflection estimator for determining a tire vertical deflection estimate from the estimated tire static load and the vehicle chassis vertical deflection;

a load variation estimator for determining a load variation estimate from the tire vertical deflection estimate; and

a tire load estimator operative to determine a substantially instantaneous load on the at least one tire based on the estimated tire static load and the load variation estimate.

2. The tire load estimation system of claim 1, wherein further comprising:

a tire inflation pressure measuring sensor mounted to the at least one tire for measuring tire inflation pressure within a tire cavity of the at least one tire;

a tire-specific stiffness database adjusted for tire inflation pressure for identifying a tire-specific stiffness for the at least one tire at the measured tire air pressure;

a tire vertical stiffness estimator for estimating a tire vertical stiffness from the tire inflation pressure and the tire-specific stiffness for the at least one tire; and

wherein the tire deflection estimator operably uses as an input the tire-specific vertical stiffness in estimating the tire vertical deflection.

3. The tire load estimation system of claim 2, wherein the at least one tire static load sensor comprises at least one tire-mounted sensor for measuring a rolling tire footprint length.

4. The tire load estimation system of claim 1, wherein the at least one vehicle chassis-mounted sensor for measuring a vehicle chassis vertical deflection comprises a chassis acceleration measuring sensor for measuring a chassis vertical acceleration;

and a hub acceleration measuring sensor for measuring a vertical acceleration of the wheel hub of the at least one tire.

5. The tire load estimation system of claim 4, wherein the tire deflection estimator comprises a linear filter model receiving as inputs the chassis vertical acceleration and the wheel hub vertical acceleration.

6. The tire load estimation system of claim 5, wherein the linear filter model comprises a Kalman filter model.

7. The tire load estimation system of claim 5, wherein further comprising:

a tire inflation pressure measuring sensor mounted to the at least one tire for measuring a tire inflation pressure within a tire cavity of the at least one tire;

a tire-specific stiffness database for identifying a tire-specific stiffness for the at least one tire at the measured tire inflation pressure; and

a tire vertical stiffness estimator for estimating a tire vertical stiffness from the measured tire air pressure and the tire-specific stiffness for the at least one tire; and

wherein the linear filter model operably uses as an input the tire vertical stiffness in estimating the tire vertical deflection estimate.

8. A tire load estimation system for a vehicle comprising:

at least one tire mounted to a wheel hub and supporting a vehicle chassis;

at least one load sensor mounted to the at least one tire for detecting a measured tire load on the at least one tire;

a tire static load estimator operable to determine a static tire load from the measured tire load;

at least one vehicle chassis-mounted sensor for measuring a vehicle chassis vertical deflection;

a tire deflection estimator operable to estimate a tire deflection by fusing the static load estimation of the at least one tire with the vehicle chassis vertical deflection;

a load variation estimator for estimating a substantially instantaneous load variation from the estimated tire deflection;

a tire load estimator for calculating a substantially instantaneous tire load estimation operably fusing the static tire load with the instantaneous load variation.

9. The tire load estimation system of claim 8, wherein the at least one static load sensor comprises at least one tire-attached sensor for measuring a length of a rolling tire footprint.

10. The tire load estimation system of claim 8, wherein the at least one vehicle chassis-mounted sensor for measuring the vehicle chassis vertical deflection comprises a chassis vertical acceleration measuring sensor for measuring a chassis vertical acceleration;

and a hub acceleration measuring sensor for measuring a vertical acceleration of the wheel hub of the at least one tire.

11. The tire load estimation system of claim 10, wherein the tire deflection estimator comprises a linear filter model receiving as inputs the vehicle chassis vertical acceleration and the wheel hub vertical acceleration.

12. The tire load estimation system of claim 11, wherein the linear filter model comprises a Kalman filter model.

13. A method of estimating a tire load for a vehicle comprising:

supporting a vehicle chassis by at least one tire mounted to a wheel hub;

detecting a measured static tire load by a tire static load sensor mounted to the at least one tire;

calculating an estimated tire static load based on the measured static tire load;

detecting a measured vehicle chassis vertical deflection from a sensor mounted to the vehicle chassis;

estimating a tire vertical deflection from the vehicle chassis vertical deflection and the static tire load;

calculating an estimated load variation from the tire vertical deflection estimation; and

estimating a substantially instantaneous tire load on the at least one tire based on the estimated tire static load and the estimated load variation.

14. The method of claim 13, wherein further comprising:

measuring a tire inflation pressure within a tire cavity;

identifying from a tire-specific stiffness database a tire-specific stiffness for the at least one tire using the measured tire inflation pressure.

15. The method of claim 14, wherein further comprising measuring a rolling tire footprint length to determine the measured static tire load.

16. The method of claim 14, wherein further comprising:

measuring a vertical acceleration of the vehicle chassis; and

measuring a vertical acceleration of the wheel hub to which the at least one tire;

estimating the tire vertical deflection from the static load estimation, vertical acceleration of the vehicle chassis, and vertical acceleration of the wheel hub.

17. The method of claim 16, wherein further comprising using a linear filter model to estimate the tire vertical deflection.