Decelerating factor estimating device

Patent metadata

Field	Value
Publication number	US-10024878-B2
Application number	US-201214376273-A
Country	US
Kind code	B2
Filing date	Feb 3, 2012
Priority date	Feb 3, 2012
Publication date	Jul 17, 2018
Grant date	Jul 17, 2018

Abstract

A decelerating factor estimating device configured to estimate a decelerating factor of a vehicle includes a drive force acquiring unit configured to acquire a drive force of the vehicle; a vehicle speed acquiring unit configured to acquire a vehicle speed of the vehicle; an acceleration acquiring unit configured to acquire an acceleration of the vehicle; and a decelerating factor estimating unit configured to estimate a plurality of decelerating factors based on a relationship of the acquired drive force, speed, and acceleration, wherein the decelerating factor estimating unit determines a type of the decelerating factor to estimate based on a traveling state of the vehicle.

First claim

The invention claimed is:

1. A decelerating factor estimating device comprising:
an electronic control unit (ECU) configured to:
acquire a drive force of a vehicle;
acquire a vehicle speed of the vehicle;
acquire an acceleration of the vehicle;
estimate a plurality of decelerating factors including a vehicle weight, an air resistance coefficient, and a road load based on a relationship among the drive force, the speed, and the acceleration;
determine a decelerating factor, from among the plurality of decelerating factors, to be estimated based on a traveling state of the vehicle;
at a time an estimated value of a first decelerating factor of the plurality of decelerating factors is converging, widen a range of the traveling state of the vehicle to execute an estimation process of a second decelerating factor of the plurality of decelerating factors relative to a case where the estimated value of the first decelerating factor is not converging; and
turn ON/OFF an engine of the vehicle based upon the deceleration factors.

2. The decelerating factor estimating device according to claim 1 , wherein
the first decelerating factor is the air resistance coefficient,
the second decelerating factor is the vehicle weight, and
the ECU is configured to:
estimate the vehicle weight at a time the vehicle speed is smaller than a threshold value, and
at a time the air resistance coefficient is converging, make a speed of the threshold value a higher speed than a case where the air resistance coefficient is not converging.

3. The decelerating factor estimating device according to claim 2 , wherein the ECU is configured to:
estimate the air resistance coefficient at a time the acceleration is smaller than a threshold value, and
at a time the vehicle weight is converging, make an acceleration of the threshold value a higher acceleration than a case where the vehicle weight is not converging.

4. The decelerating factor estimating device according to claim 2 , wherein the ECU is configured to estimate the road load at the time the vehicle speed is smaller than the threshold value.

5. The decelerating factor estimating device according to claim 2 , wherein the ECU is configured to:
estimate the road load at a time the acceleration is smaller than a threshold value, and
at a time the vehicle weight is converging, make an acceleration of the threshold value a higher acceleration than a case where the vehicle weight is not converging.

6. The decelerating factor estimating device according to claim 2 , wherein the ECU is configured to stop the estimation of at least one of the air resistance coefficient and the road load at a time the vehicle weight is greater than or equal to a threshold value.

7. The decelerating factor estimating device according to claim 2 , wherein the ECU is configured to:
detect actuation of a vehicle behavior stability control, and
stop the estimation of the decelerating factor at a time that it is detected that the vehicle behavior stability control is actuated.

8. The decelerating factor estimating device according to claim 1 , wherein
the first decelerating factor is the vehicle weight,
the second decelerating factor is the air resistance coefficient,
the ECU is configured to:
estimate the air resistance coefficient at a time the acceleration is smaller than a threshold value, and
at a time the vehicle weight is converging, make an acceleration of the threshold value a higher acceleration than a case where the vehicle weight is not converging.

9. The decelerating factor estimating device according to claim 8 , wherein the ECU is configured to:
estimate the road load at a time the vehicle speed is smaller than a threshold value, and
at a time the air resistance coefficient is converging, make a vehicle speed of the threshold value a higher vehicle speed than a case where the air resistance coefficient is not converging.

10. The decelerating factor estimating device according to claim 8 , wherein the ECU is configured to estimates the road load at the time the acceleration is smaller than the threshold value.

11. The decelerating factor estimating device according to claim 8 , wherein the ECU is configured to stop the estimation of at least one of the air resistance coefficient and the road load at a time the vehicle weight is greater than or equal to a threshold value.

12. The decelerating factor estimating device according to claim 1 , wherein
the first decelerating factor is the air resistance coefficient,
the second decelerating factor is the road load,
the ECU is configured to:
estimate the road load at a time the vehicle speed is smaller than a threshold value, and
at a time the air resistance coefficient is converging, make a vehicle speed of the threshold value a higher vehicle speed than a case where the air resistance coefficient is not converging.

13. The decelerating factor estimating device according to claim 12 , wherein the ECU is configured to:
estimate the road load at a time the acceleration is smaller than a threshold value, and
at a time the vehicle weight is converging, make an acceleration of the threshold value a higher acceleration than a case where the vehicle weight is not converging.

14. The decelerating factor estimating device according to claim 12 , wherein the ECU is configured to stop the estimation of at least one of the air resistance coefficient and the road load at a time the vehicle weight is greater than or equal to a threshold value.

15. The decelerating factor estimating device according to claim 1 , wherein
the first decelerating factor is the vehicle weight,
the second decelerating factor is the road load,
the ECU is configured to:
estimate the road load at a time the acceleration is smaller than a threshold value, and
at a time the vehicle weight is converging, make an acceleration of the threshold value a higher acceleration than a case where the vehicle weight is not converging.

16. The decelerating factor estimating device according to claim 15 , wherein the ECU is configured to stop the estimation of at least one of the air resistance coefficient and the road load of at a time the vehicle weight is greater than or equal to a threshold value.

17. The decelerating factor estimating device according to claim 1 , wherein the ECU is configured to stop the estimation of at least one of the air resistance coefficient and the road load at a time the vehicle weight is greater than or equal to a threshold value.

18. The decelerating factor estimating device according to claim 1 , wherein the ECU is configured to:
detect actuation of a vehicle behavior stability control, and
stop the estimation of the decelerating factor at a time that it is detected that the vehicle behavior stability control is actuated.

19. The decelerating factor estimating device according to claim 1 , wherein the ECU is configured to determine the decelerating factor to be estimated based on the vehicle speed and the acceleration.

20. The decelerating factor estimating device according to claim 1 , wherein the ECU is configured to:
analyze a relationship among two of the decelerating factors, the drive force, the speed, and the acceleration using a motion equation, and
estimate a remaining decelerating factor.

Assignees

• Sannodo Shinya
• Otake Hirotada
• Toyota Motor Co Ltd

Inventors

• Sannodo Shinya
• Otake Hirotada

Classifications

• B60W2556/45

  External transmission of data to or from the vehicle · CPC title

• B60W2555/60

  Traffic rules, e.g. speed limits or right of way · CPC title

• B60W2556/50

  of positioning data, e.g. GPS [Global Positioning System] data · CPC title

• B60W30/143 Primary

  Speed control (B60W30/16 takes precedence) · CPC title

• B60W2520/10

  Longitudinal speed · CPC title