System and method for determining effective road grade characteristic

• US 9,616,898 B2
• Filed: 04/14/2014
• Issued: 04/11/2017
• Est. Priority Date: 12/12/2013
• Status: Active Grant

• Current Assignee: Ford Global Technologies, LLC (Ford Motor Company)
• Original Assignee: Ford Global Technologies, LLC (Ford Motor Company)
• Inventors: D'Amato, Anthony Mario, Mullen, Jonathan Thomas, Michelini, John Ottavio, Szwabowski, Steven Joseph, Filev, Dimitar Petrov
• Primary Examiner(s): CASS, JEAN PAUL
• Application Number:
  US14/252,193
• Publication Number:
  US 20150166073A1
• Time in Patent Office: 1,093 Days
• Field of Search: 701 1
• CPC Class Codes: B60W 2520/10 Longitudinal speed
• CPC Class Codes: B60W 2520/105 Longitudinal acceleration
• CPC Class Codes: B60W 2540/10 Accelerator pedal position
• CPC Class Codes: B60W 2552/15 Road slope, i.e. the inclination of a road segment in the longitudinal direction
• CPC Class Codes: B60W 2556/50 of positioning data, e.g. GPS [Global Positioning System] data
• CPC Class Codes: B60W 40/076 Slope angle of the road

Abstract

A vehicle system includes a computer in a vehicle, and the computer includes a processor and a memory. The computer is configured to determine an operational state of a vehicle, calculate a road grade value from data from a first sensor, calculate an effective road grade value from a torque demand value, update modeling variables to map the road grade value substantially to the effective grade value when the operation state is determined to be a steady-state condition, and calculate a road grade characteristic with the road grade value and the modeling variables.

Claims

1. A system comprising a computer in a vehicle, the computer comprising a processor and a memory, wherein the computer is configured to:

determine an operational state of a vehicle;

calculate a road grade value from data from an accelerometer;

calculate an effective grade value from a torque demand value;

determine a correction coefficient to adjust the road grade value to substantially match the effective grade value when the operation state is determined to be a steady-state condition;

determine a corrected effective grade based at least in part on the correction coefficient and the road grade value; and

adjust a velocity of the vehicle with a cruise control system based at least in part on the corrected effective grade when the operation state is a transient condition;

wherein the correction coefficient is based at least in part on the road grade value and the effective grade value.

2. The vehicle system of claim 1, wherein the computer is further configured to estimate the torque demand value from collected data.

3. The vehicle system of claim 2, wherein the collected data includes at least one of vehicle speed data, requested torque data, and vehicle acceleration data.

4. The vehicle system of claim 1, wherein the road grade value is calculated from data from the accelerometer and a vehicle speed sensor.

5. The vehicle system of claim 1, wherein the correction coefficient is determined with a least-squares calculation.

6. A method comprising:

determining an operational state of a vehicle;

calculating a road grade value from data from an accelerometer;

calculating an effective grade value from a torque demand value;

determining a correction coefficient to adjust the road grade value to substantially match the effective grade value when the operation state is determined to be a steady-state condition,

determining a corrected effective grade based at least in part on the correction coefficient and the road grade value; and

adjusting a velocity of the vehicle with a cruise control system based at least in part on the corrected effective grade when the operation state is a transient condition;

wherein the correction coefficient is based at least in part on the road grade value and the effective grade value.

7. The method of claim 6, further comprising estimating the torque demand value from collected data.

8. The method of claim 7, wherein the collected data includes at least one of vehicle speed data, requested torque data, and vehicle acceleration data.

9. The method of claim 6, wherein the road grade value is calculated from data from the accelerometer and a vehicle speed sensor.

10. The method of claim 6, where the correction coefficient is determined with a least-squares calculation.

11. A non-transitory computer-readable medium tangibly embodying computer-executable instructions that cause a processor to execute operations comprising:

determining an operational state of a vehicle;

calculating a road grade value from data from an accelerometer;

calculating an effective grade value from a torque demand value;

determining a correction coefficient to adjust the road grade value to substantially match the effective grade value when the operation state is determined to be a steady-state condition,

determining a corrected effective grade based at least in part on the correction coefficient and the road grade value; and

adjusting a velocity of the vehicle with a cruise control system based at least in part on the corrected effective grade when the operation state is a transient condition;

wherein the correction coefficient is based at least in part on the road grade value and the effective grade value.

12. The non-transitory computer-readable medium of claim 11, the operations further comprising estimating the torque demand value from collected data.

13. The non-transitory computer-readable medium of claim 12, wherein the collected data includes at least one of vehicle speed data, requested torque data, and vehicle acceleration data.

14. The non-transitory computer-readable medium of claim 11, wherein the road grade value is calculated from data from the accelerometer and a vehicle speed sensor.

15. The non-transitory computer-readable medium of claim 11, wherein the correction coefficient is determined with a least-squares calculation.