IN-VEHICLE DETERMINATION OF THE RELATIVE CENTER OF GRAVITY HEIGHT

• US 20070129867A1
• Filed: 11/27/2006
• Published: 06/07/2007
• Est. Priority Date: 12/02/2005
• Status: Active Grant

• Current Assignee: GM Global Technology Operations LLC (General Motors Company)
• Original Assignee: GM Global Technology Operations Incorporated (Motors Liquidation Co. GUC Trust)
• Inventors: Huang, Jihua, Lin, William
• Granted Patent: US 7,526,376 B2
• Time in Patent Office: Days
• US Class Current: 701/124
• CPC Class Codes: B60W 30/04 related to roll-over prevention
• CPC Class Codes: B60W 40/12 related to parameters of the vehicle itself , e.g. tyre models

Abstract

Relative center of gravity height in a motor vehicle changes from a nominal value to an actual value depending upon vehicle loading. Method and apparatus for determining actual relative center of gravity height are disclosed.

Claims

1. Method for determining relative CG height in a vehicle, comprising:

sensing vehicle roll; and

estimating relative CG height based on vehicle dynamics data collected during said vehicle roll.

2. The method for determining relative CG height in a vehicle, as claimed in claim 1 wherein detecting vehicle roll comprises detecting vehicle roll within a predetermined range.

3. The method for determining relative CG height in a vehicle, as claimed in claim 1 wherein estimating relative CG height comprises:

calculating CG height candidates based on a nominal CG height;

estimating vehicle roll corresponding to the CG height candidates;

determining as the relative CG height one of the CG height candidates corresponding to an estimated vehicle roll that differs from the sensed vehicle roll by less than a predetermined amount.

4. The method for determining relative CG height in a vehicle as claimed in claim 3 wherein said nominal relative CG height comprises a calibration.

5. The method for determining relative CG height in a vehicle as claimed in claim 3 wherein said nominal relative CG height comprises a previously determined relative CG height.

6. The method for determining relative CG height in a vehicle as claimed in claim 1 wherein said method is performed at least once per ignition cycle of the vehicle.

7. Method for determining relative CG height in a vehicle, comprising:

measuring a vehicle dynamics state;

providing a nominal relative CG height;

calculating CG height candidates based on the nominal CG height;

estimating a vehicle dynamics state corresponding to the CG height candidates; and

determining as the relative CG height one of the CG height candidates corresponding to an estimated vehicle dynamics state that differs from the measured vehicle dynamics state by less than a predetermined amount.

8. The method for determining relative CG height in a vehicle as claimed in claim 7 wherein said vehicle dynamics state comprises at least one of vehicle roll rate and vehicle yaw rate.

9. The method for determining relative CG height in a vehicle as claimed in claim 7 wherein said nominal relative CG height comprises a calibration.

10. The method for determining relative CG height in a vehicle as claimed in claim 7 wherein said nominal relative CG height comprises a previously determined relative CG height.

11. The method for determining relative CG height in a vehicle as claimed in claim 7 wherein said method is performed at least once per ignition cycle of the vehicle.

12. Apparatus for determining relative CG height in a vehicle, comprising:

a plurality of vehicle dynamics sensors adapted to provide vehicle dynamics data;

a controller adapted to receive the vehicle dynamics data and including a computer readable storage medium storing computer code adapted for determining relative CG height of the vehicle based on said vehicle dynamics data, said computer code including;

code for measuring vehicle roll from said vehicle dynamics data;

code for estimating relative CG height;

code for calculating vehicle roll based on vehicle dynamics data and estimated relative CG height;

code for comparing measured vehicle roll to calculated vehicle roll and establishing therefrom vehicle roll deviation; and

code for determining relative CG height as estimated relative CG height corresponding to vehicle roll deviation less than a predetermined deviation.