Tire load estimation system using road profile adaptive filtering

• US 8,844,346 B1
• Filed: 03/08/2013
• Issued: 09/30/2014
• Est. Priority Date: 03/08/2013
• Status: Active Grant

• Current Assignee: Goodyear Tire & Rubber Company
• Original Assignee: Goodyear Tire & Rubber Company
• Inventors: Singh, Kanwar Bharat, Parsons, Anthony William, Engel, Marc, Suh, Peter Jung-min
• Primary Examiner(s): Tarcza, Thomas
• Assistant Examiner(s): Lee, Tyler J
• Application Number:
  US13/789,881
• Publication Number:
  US 20140257629A1
• Time in Patent Office: 571 Days
• Field of Search: 701/36, 701/37, 701/41, 701/48, 701/124, 701/29.1, 701/31.4, 701/34.4, 701/72, 702/34, 702/35, 702/189, 731/46, 731/462, 152/151, 340/442, 340/443
• US Class Current: 73/146
• 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: B60T 2210/14 Rough roads, bad roads, gravel roads
• CPC Class Codes: B60T 2240/06 Wheel load; Wheel lift
• CPC Class Codes: B60T 8/1725 Using tyre sensors, e.g. Sidewall Torsion sensors [SWT] for tyre pressure and temperature detection B60C23/00
• CPC Class Codes: B60W 40/13 Load or weight
• CPC Class Codes: G01G 19/08 for incorporation in vehicles
• CPC Class Codes: G01G 19/12 having electrical weight-sensitive devices
• CPC Class Codes: G01M 17/02 Tyres
• CPC Class Codes: G07C 5/0808 Diagnosing performance data testing of vehicles G01M17/00; testing of electrical installation on vehicles G01R31/005

Abstract

A dynamic load estimation system is provided including: a vehicle load bearing tire; at least one tire sensor mounted to the tire, the sensor operable to measure a tire deformation of the one tire and generate a raw load-indicating signal conveying measured deformation data; road roughness estimation means for determining a road roughness estimation; filtering means for filtering the measured deformation data by the road roughness estimation; and load estimation means for estimating an estimated load on the one tire from filtered measured deformation data. A road profile estimate is fused with the static load estimate in order to obtain an instantaneous tire load estimate.

Claims

1. A dynamic load estimation system for estimating a vehicle load comprising:

at least one tire supporting a vehicle;

tire sensor means mounted to the one tire, the sensor means operable to measure a tire deformation of the one tire and generate a load-indicative raw signal conveying measured deformation data;

load estimation means for determining an unfiltered load estimation on the tire from the load-indicative raw signal;

road roughness estimation means for determining a road roughness estimation;

filtering means for filtering the unfiltered load estimation by the road roughness estimation; and

load estimation means for determining a filtered load estimation on the one tire from the filtering means.

2. The load estimation system of claim 1, wherein the tire sensor means comprises energy harvesting means, the load-indicative raw signal representing energy harvested from deformation of the one tire.

3. The load estimation system of claim 1, wherein the tire sensor means comprises at least one piezo-based sensor.

4. The load estimation system of claim 1, wherein the filtering means comprises an adaptive filtering means.

5. The load estimation system of claim 4, wherein the adaptive filtering means comprises an adaptive Kalman filter using a recursive-based procedure.

6. The load estimation system of claim 5, wherein the load estimation means determines an estimated unfiltered footprint length of the tire from the load-indicative raw signal.

7. The load estimation system of claim 6, wherein the adaptive Kalman filter determines a filtered footprint length estimation from the estimated unfiltered footprint length.

8. The load estimation system of claim 7, further comprising a tire-specific database determining a load estimation on the one tire from inputs comprising the filtered footprint length estimation, measured tire inflation pressure and tire identification data.

9. The load estimation system of claim 8, wherein the road roughness estimation means operatively applying a surface roughness classification system to the load-indicative raw signal to determine a relative road roughness estimation, the adaptive filtering means being operative to filter the estimated unfiltered footprint length by the relative road roughness estimation.

10. The load estimation system of claim 5, wherein further comprising road profile height estimating means for determining an estimated quantified road profile height from at least one vehicle-mounted sensor means.

11. The load estimation system of claim 10, wherein the vehicle-mounted sensor means comprises suspension deflection measuring means.

12. The load estimation system of claim 11, wherein the vehicle mounted sensor means further comprises chassis mounted accelerometer means for measuring vehicle chassis acceleration.

13. The load estimation system of claim 12, wherein an estimated road profile height is operatively fused with the filtered load estimation to yield a calculated instantaneous tire load estimation.

14. A method of estimating a dynamic load on a vehicle supporting tire comprising:

mounting tire sensor means to the one tire, the sensor means operable to measure a tire deformation of the one tire and generate a load-indicative raw signal conveying measured deformation data;

determining a road roughness estimation from road roughness estimation means utilizing the load-indicative raw signal;

calculating an unfiltered load estimation from the load-indicative raw signal;

filtering the unfiltered load estimation by the road roughness estimation utilizing adaptive filter means; and

estimating a filtered load estimation on the one tire subsequent to filtering by the adaptive filter means.

15. The method of claim 14, wherein further comprising configuring the tire sensor means as an energy harvesting sensor means to generate the load-indicative raw signal.

16. The method of claim 15, wherein the adaptive filtering means comprises an adaptive Kalman filter using a recursive-based procedure.

17. The method of claim 16, further comprising determining, by means of a tire-specific database, a load estimation on the one tire from inputs comprising the filtered footprint length estimation, measured tire inflation pressure and tire identification data.

18. The method of claim 17, wherein further comprising applying a surface roughness classification system to the raw load-indicating signal to determine a relative road roughness estimation and filtering by means of the adaptive filtering means an unfiltered tire load estimation by the relative road roughness estimation.

19. The method of claim 16, wherein further comprising calculating a road profile estimation from at least one vehicle-mounted sensor means.

20. The method of claim 19, wherein further comprising fusing an estimated road profile height with the filtered load estimation to yield a calculated instantaneous tire load estimation.