Method of optimizing vehicle performance based on countershaft acceleration
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.
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.