Use of on-vehicle accelerometer to estimate vehicle grade and mass while vehicle is in motion

• US 8,977,415 B2
• Filed: 08/02/2011
• Issued: 03/10/2015
• Est. Priority Date: 08/02/2011
• Status: Active Grant

• Current Assignee: GM Global Technology Operations LLC (General Motors Company)
• Original Assignee: GM Global Technology Operations LLC (General Motors Company)
• Inventors: Tiberg, Richard L.
• Primary Examiner(s): Nguyen, Cuong H
• Application Number:
  US13/196,329
• Publication Number:
  US 20130035829A1
• Time in Patent Office: 1,316 Days
• Field of Search: 701 55- 56, 701/102, 701/65, 701/33.4, 701/37, 701/90, 701/120, 701/35, 701/22, 738/65, 702/175, 180/6.48
• US Class Current: 701/22
• CPC Class Codes: B60W 10/11 Stepped gearings
• CPC Class Codes: B60W 2520/105 Longitudinal acceleration
• CPC Class Codes: B60W 40/076 Slope angle of the road
• CPC Class Codes: B60W 40/13 Load or weight
• CPC Class Codes: F16H 2059/663 Road slope
• CPC Class Codes: F16H 2061/0227 Shift map selection, i.e. methods for controlling selection between different shift maps, e.g. to initiate switch to a map for up-hill driving
• CPC Class Codes: F16H 59/52 dependent on the weight of the machine, e.g. change in weight resulting from passengers boarding a bus
• CPC Class Codes: F16H 59/66 Road conditions, e.g. slope, slippery
• CPC Class Codes: F16H 61/0213 characterised by the method for generating shift signals

Abstract

A system includes a grade estimation module that receives an accelerometer value and generates a grade estimate based on the accelerometer value, wherein the accelerometer value corresponds to acceleration of a vehicle and the grade estimate corresponds to a grade of the vehicle. A mass estimation module receives the accelerometer value and generates a mass estimate based on the accelerometer value, wherein the mass estimate corresponds to a mass of the vehicle. A shift control module at least one of selects and adjusts one of a plurality of shift schedules based on at least one of the grade estimate and the mass estimate and controls a transmission of the vehicle based on the one of the plurality of shift schedules.

Claims

1. A system comprising:

a grade estimation module that receives an accelerometer value and generates a grade estimate based on the accelerometer value, wherein the accelerometer value corresponds to acceleration of a vehicle and the grade estimate corresponds to a grade of the vehicle;

a mass estimation module that receives the accelerometer value and generates a mass estimate based on the accelerometer value, wherein the mass estimate corresponds to a mass of the vehicle; and

a shift control module that;

selects one of a plurality of shift schedules based on at least one of the grade estimate and the mass estimate;

adjusts the selected one of the plurality of shift schedules based on at least one of the grade estimate and the mass estimate; and

controls a transmission of the vehicle based on the one of the plurality of shift schedules.

2. The system of claim 1 further comprising an accelerometer that generates the accelerometer value.

3. The system of claim 1 wherein the grade estimation module generates the grade estimate based on the accelerometer value, a rate of change of vehicle speed, and a gravitational constant.

4. The system of claim 1 wherein the grade estimation module generates the grade estimate according to

5. The system of claim 1 wherein the mass estimation module generates the mass estimate based on the accelerometer value, tractive force of the vehicle, an aerodynamic coefficient of the vehicle, a speed of the vehicle, a rolling load of the vehicle, and braking force of the vehicle.

6. The system of claim 1 wherein the mass estimation module generates the mass estimate according to

7. The system of claim 1 wherein the shift control module at least one of selects and adjusts the one of the plurality of shift schedules in response to the grade estimate being greater than or equal to a threshold.

8. The system of claim 1 wherein the shift control module at least one of selects and adjusts the one of the plurality of shift schedules in response to the mass estimate being greater than or equal to a threshold.

9. The system of claim 1 wherein the shift control module at least one of selects and adjusts the one of the plurality of shift schedules in response to the grade estimate being greater than or equal to a first threshold and the mass estimate being greater than or equal to a second threshold.

10. The system of claim 1 wherein the selected one of the plurality of shift schedules corresponds to one of a tow/haul shift schedule and a grade braking shift schedule.

11. A method comprising:

receiving an accelerometer value;

generating a grade estimate based on the accelerometer value, wherein the accelerometer value corresponds to acceleration of a vehicle and the grade estimate corresponds to a grade of the vehicle;

generating a mass estimate based on the accelerometer value, wherein the mass estimate corresponds to a mass of the vehicle;

selecting one of a plurality of shift schedules based on at least one of the grade estimate and the mass estimate;

adjusting the selected one of the plurality of shift schedules based on at least one of the grade estimate and the mass estimate; and

controlling a transmission of the vehicle based on the one of the plurality of shift schedules.

12. The method of claim 11 further comprising generating the accelerometer value using an accelerometer.

13. The method of claim 11 further comprising generating the grade estimate based on the accelerometer value, a rate of change of vehicle speed, and a gravitational constant.

14. The method of claim 11 further comprising generating the grade estimate according to

15. The method of claim 11 further comprising generating the mass estimate based on the accelerometer value, tractive force of the vehicle, an aerodynamic coefficient of the vehicle, a speed of the vehicle, a rolling load of the vehicle, and braking force of the vehicle.

16. The method of claim 11 further comprising generating the mass estimate according to

17. The method of claim 11 further comprising at least one of selecting and adjusting the one of the plurality of shift schedules in response to the grade estimate being greater than or equal to a threshold.

18. The method of claim 11 further comprising at least one of selecting and adjusting the one of the plurality of shift schedules in response to the mass estimate being greater than or equal to a threshold.

19. The method of claim 11 further comprising at least one of selecting and adjusting the one of the plurality of shift schedules in response to the grade estimate being greater than or equal to a first threshold and the mass estimate being greater than or equal to a second threshold.

20. The method of claim 11 wherein the one of the plurality of shift schedules corresponds to one of a tow/haul shift schedule and a grade braking shift schedule.