Method of optimizing vehicle performance based on countershaft acceleration

Patent metadata

Field	Value
Publication number	US-9586571-B2
Application number	US-201514797701-A
Country	US
Kind code	B2
Filing date	Jul 13, 2015
Priority date	Sep 9, 2011
Publication date	Mar 7, 2017
Grant date	Mar 7, 2017

Abstract

The present invention provides a method of controlling input torque of a powered vehicle. The vehicle includes a transmission having an input shaft, an output shaft, and a countershaft. The method includes providing input torque to the input shaft, determining a rotational acceleration of the countershaft, and measuring vehicle speed. The method also includes determining a threshold based on the measured vehicle speed. The measured countershaft acceleration is compared to the threshold and the input torque is controlled based on the result of the comparison.

First claim

What is claimed is:

1. A method of controlling input torque of a powered vehicle, the vehicle including a transmission having an input shaft, an output shaft, and a countershaft, comprising:
providing input torque to the input shaft;
determining a rotational acceleration of the countershaft;
measuring vehicle speed;
determining a threshold based on the measured vehicle speed;
comparing the countershaft acceleration to the threshold; and
controlling the input torque based on the result of the comparison.

2. The method of claim 1 , further comprising:
continuously measuring countershaft speed with a speed sensor over a time period; and
calculating countershaft acceleration over the time period.

3. The method of claim 1 , wherein the controlling comprises limiting the input torque.

4. The method of claim 1 , wherein the controlling comprises maintaining the amount of input torque provided to the input shaft.

5. The method of claim 1 , further comprising sending a signal to an engine control circuit to control the input torque.

6. The method of claim 1 , further comprising repeating the comparing step until the countershaft acceleration is less than the threshold.

7. The method of claim 1 , wherein the threshold is determined from an acceleration curve based on vehicle speed and vehicle acceleration.

8. The method of claim 1 , further comprising:
interpolating between at least two vehicle acceleration data points; and
determining the threshold based on the result of the interpolating step.

9. The method of claim 1 , further comprising sending a signal to an engine control circuit to increase the amount of input torque provided to the input shaft until the countershaft acceleration is within a percentage of the threshold.

10. A method of controlling input torque being transferred from an engine to a transmission of a powered vehicle, comprising;
(a) transferring torque to an input of the transmission;
(b) measuring a rotational speed of a countershaft in the transmission;
(c) computing an acceleration of the countershaft based on the measured rotational speed;
(d) determining a vehicle acceleration threshold based on vehicle speed;
(e) comparing countershaft acceleration to the threshold; and
(f) controlling input torque based on the result of the comparison.

11. The method of claim 10 , wherein the controlling step comprises limiting the input torque.

12. The method of claim 11 , wherein the limiting step comprises reducing the input torque until the countershaft acceleration is less than the threshold.

13. The method of claim 10 , further comprising sending a signal to an engine control circuit to control the amount of input torque transferred to the transmission input.

14. The method of claim 10 , wherein steps (b)-(e) are continuously repeated until the countershaft acceleration is less than the threshold.

15. The method of claim 10 , wherein the threshold is determined from an acceleration curve based on vehicle speed and vehicle acceleration.

16. The method of claim 10 , further comprising:
interpolating between at least two vehicle acceleration data points; and
determining the threshold based on the result of the interpolating step.

17. The method of claim 10 , further comprising sending a signal to an engine control circuit to increase the amount of input torque provided to the input shaft until the countershaft acceleration is within a percentage of the threshold.

Assignees

• Allison Transm Inc

Inventors

• Kreese John P
• Sheets Avery T

Classifications

• B60W30/188 Primary

  Controlling power parameters of the driveline, e.g. determining the required power · CPC title

• B60W2710/0666

  Engine torque · CPC title

• B60W2510/1045

  Output speed change rate · CPC title

• F16H59/38

  of gearing elements · CPC title

• B60W10/06 Primary

  including control of combustion engines · CPC title