Vehicle weight and center of gravity estimation system and method

• US 9,358,846 B2
• Filed: 10/19/2012
• Issued: 06/07/2016
• Est. Priority Date: 10/19/2012
• Status: Active Grant

• Current Assignee: Goodyear Tire & Rubber Company
• Original Assignee: Goodyear Tire & Rubber Company
• Inventors: Singh, Kanwar Bharat, Fenkanyn, John Michael, Patel, Amrita, Suh, Peter Jung-min, Goldstein, Arthur Allen
• Primary Examiner(s): Olszewski, John R
• Assistant Examiner(s): CASS, JEAN PAUL
• Application Number:
  US13/655,787
• Publication Number:
  US 20140114558A1
• Time in Patent Office: 1,327 Days
• Field of Search: 701/124
• US Class Current: 1/1
• CPC Class Codes: B60C 23/0488 Movement sensor, e.g. for sensing angular speed, acceleration or centripetal force
• CPC Class Codes: G01G 19/086 wherein the vehicle mass is dynamically estimated

Abstract

A load estimation system and method for estimating vehicle load includes a tire rotation counter for generating a rotation count from rotation of a tire; apparatus for measuring distance travelled by the vehicle; an effective radius calculator for calculating effective radius of the tire from the distance travelled and the rotation count; and a load estimation calculator for calculating the load carried by the vehicle tire from the effective radius of the tire. A center of gravity height estimation may be made from an estimated total load carried by the tires supporting the vehicle pursuant to an estimation of effective radius for each tire and a calculated load carried by each tire from respective effective radii.

Claims

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

at least one tire supporting a vehicle;

a tire-mounted sensor attached to the tire and comprising a rotation counter for generating a rotation count from rotation of the tire;

a vehicle-based distance measuring device measuring distance travelled by the vehicle and producing distance travelled input data;

an effective radius calculator calculating effective radius of the tire from the distance travelled and the rotation count; and

wherein the effective radius calculator operably calculates effective radius of the tire by dividing a distance measured by the distance measuring device by a product of the rotation count times 2π

;

a rotation time measuring calculator for measuring the time for one rotation from data derived from the tire-mounted sensor;

a vehicle speed calculating calculator for calculating vehicle speed by dividing the effective radius of the tire times 2π

by the time for one rotation pursuant to the formula;

Vehicle speed=(Effective Radius of Tire*2π

)/(Time of one revolution);

load estimation means for calculating the load carried by the vehicle tire from the effective radius;

wherein data from the load estimating means is communicated to an operator of the vehicle by a communication device that is operative connected to the vehicle or communicated to a vehicle control device.

2. The load estimation system of claim 1, wherein the distance measuring device comprises a global positioning system.

3. A load estimation system for estimating a vehicle load comprising:

at least one tire supporting a vehicle;

a tire-mounted sensor attached to the tire and comprising a rotation counter for generating a rotation count from rotation of the tire;

a vehicle-based distance measuring device measuring distance travelled by the vehicle and producing distance travelled input data;

an effective radius calculator calculating effective radius of the tire from the distance travelled and the rotation count;

load estimation means for calculating the load carried by the vehicle tire from the effective radius; and

wherein data from the load estimating means is communicated to an operator of the vehicle by a communication device that is operative connected to the vehicle or communicated to a vehicle control device;

wherein the distance measuring device comprises a global positioning system;

wherein the effective radius calculator operably calculates effective radius of the tire by dividing a distance measured by the global positioning system by a product of the rotation count times 2π

;

wherein further comprising a rotation time measuring calculator for measuring the time for one rotation from data derived from the tire-mounted sensor; and

a vehicle speed calculating calculator for calculating vehicle speed by dividing the effective radius of the tire times 2π

by the time for one rotation pursuant to the formula;

Vehicle speed=(Effective Radius of Tire*2π

)/(Time of one revolution).

4. The load estimation system of claim 3, wherein further comprising a tire-based tire pressure and temperature monitoring sensor for measuring tire pressure and tire temperature.

5. The load estimation system of claim 4, wherein the load estimation means comprises a computer receiving as inputs from the tire-based sensor the tire pressure, tire temperature, and receiving as further inputs the effective radius, and vehicle speed, and the computer calculating a load estimation from the inputs by means of a load estimation algorithm.

6. The load estimation system of claim 5, wherein further comprising tire vertical stiffness calculating means for determining a tire vertical stiffness from the tire-based sensor tire pressure and tire temperature measurements, and the vehicle speed, the calculated tire vertical stiffness comprising a further input into the load estimation algorithm.

7. The load estimation system of claim 6, wherein the load estimation algorithm comprises a recursive least squares algorithm receiving as input the tire vertical stiffness, the tire effective rolling radius, and a tire original radius as inputs.

8. The load estimation system of claim 5, wherein the load estimation means operably calculates a respective load carried by a plurality of tires supporting the vehicle.

9. The load estimation system of claim 8, wherein an estimated total load carried by the vehicle comprises a summation of the respective loads of the plurality of tires.

10. The load estimation system of claim 9, further comprising a center of gravity height estimation means for estimating a vehicle center of gravity from the estimated total load.

11. A method of determining an estimated vehicle load carried by a tire comprising:

determining a rotation count from a tire-mounted sensor affixed to the tire;

measuring the distance travelled by the vehicle from a vehicle-based distance-measuring device;

calculating an effective radius of the tire from the distance travelled and the rotation count; and

calculating the load carried by the vehicle tire from the effective radius;

communicating data representing the load calculation to an operator of the vehicle by a communication device that is operative connected to the vehicle or communicated to a vehicle control device;

wherein the vehicle-based distance measuring device comprises a global positioning system;

wherein calculating an effective radius of the tire comprises dividing a distance measured by the global positioning system by the rotation count times 2π

; and

measuring rotation time for one rotation of the tire from a tire-based sensor; and

calculating vehicle speed from dividing the product of the effective radius of the tire times 2π

by the time for one rotation pursuant to the formula;

Vehicle speed=(Effective Radius of Tire*2π

)/(Time of one revolution).

12. The method of claim 11, wherein further comprising measuring tire pressure and tire temperature of the tire respectively from a tire-based sensor;

and using the sensor-measured tire pressure and tire temperature, and effective radius, and vehicle speed as collective inputs in calculating a load estimation by means of a load estimation algorithm.

13. The method of claim 12, wherein further comprising determining a tire vertical stiffness from the sensor-measured tire pressure and tire temperature, and vehicle speed and using the vertical stiffness as an additional input in the load estimation algorithm.

14. The method of claim 13, wherein further comprising estimating a total load carried by the vehicle by a summation of respective loads on a plurality of tires.

15. The method of claim 14, further comprising estimating a center of gravity of the vehicle from the estimated total load.