Transmission control system for an electric vehicle

1. A method of controlling a transmission of a vehicle powered by an electric motor, comprising:

initiating a gear engagement in the transmission when the vehicle is in motion; and

activating a torque jog in the electric motor to assist with the gear engagement, wherein the torque jog includes a fluctuation in the torque output of the electric motor above and below a fixed value.

2. The method of claim 1 , further including determining whether or not a successful gear engagement occurred within a predetermined time period after initiating the gear engagement.

3. The method of claim 2 , wherein the torque jog is activated if a successful gear engagement did not occur within the predetermined time period.

4. The method of claim 1 , further including initiating a gear shift before initiating the gear engagement, wherein the gear shift includes a downshift.

5. The method of claim 1 , further including initiating a gear shift before initiating the gear engagement, wherein the gear shift includes an upshift.

6. The method of claim 1 , wherein the fluctuation in torque output terminates in less than or equal to 500 milliseconds.

7. The method of claim 1 , wherein the fluctuation in torque output includes increasing the torque output by about 1-20% from the fixed value, and decreasing the torque output by about 1-20% from the fixed value.

8. A method of controlling a transmission of a vehicle powered by an electric motor, comprising:

initiating a gear engagement in the transmission;

determining whether or not a successful gear engagement occurred in response to the initiation; and

activating a torque jog in the electric motor based on the determination, wherein the torque jog includes a fluctuation in the torque output of the electric motor above and below a fixed value to assist with the gear engagement, the fluctuation including increasing the torque output by about 1-20% from the fixed value, and decreasing the torque output by about 1-20% from the fixed value.

9. The method of claim 8 , wherein the determining includes determining whether or not a successful gear shift occurred within a predetermined time period.

10. The method of claim 8 , wherein the fluctuation in torque output ends in less than or equal to 500 milliseconds.

11. The method of claim 8 , wherein activating the torque jog includes activating the torque jog only if successful gear engagement did not occur in response to the initiation.

12. The method of claim 8 , wherein determining whether or not a successful gear engagement occurred includes receiving a signal indicative of gear engagement within a predetermined time.

13. The method of claim 8 , wherein activating the torque jog includes activating the torque jog a predetermined time after initiating the gear engagement.

14. The method of claim 8 , wherein the electric vehicle is an electric bus.

15. The method of claim 8 , wherein the electric vehicle is a low-floor electric bus.

16. An electric vehicle, comprising:

an electric motor configured to provide traction for the electric vehicle;

a transmission coupled to the electric motor, the transmission including a plurality of gears therein; and

a control unit operatively coupled to the transmission and the electric motor, wherein the control unit is configured to:

initiate a gear engagement in the transmission when the vehicle is in motion; and

activate a torque jog in the electric motor to assist with the gear engagement, wherein the torque jog includes a fluctuation in the torque output of the electric motor above and below a fixed value.

17. The electric vehicle of claim 16 , further including a sensor associated with the transmission, the sensor being configured to detect whether or not a successful gear engagement occurred in response to the initiation of gear engagement.

18. The electric vehicle of claim 17 , wherein the control unit is configured to activate the torque jog only if successful gear engagement is not detected within a predetermined time.

19. The electric vehicle of claim 16 , wherein the fluctuation ends in less than or equal to 500 milliseconds.

20. The electric vehicle of claim 16 , wherein the fluctuation in torque output includes increasing the torque output by about 1-20% from the fixed value, and decreasing the torque output by about 1-20% from the fixed value.

21. A method of controlling a transmission of a vehicle powered by an electric motor, comprising:

initiating a gear engagement in the transmission; and

activating a torque jog in the electric motor to assist with the gear engagement, wherein the torque jog includes a fluctuation in the torque output of the electric motor, and wherein the torque jog is activated before initiating the gear engagement.

22. The method of claim 21 , further including initiating a gear shift prior to the initiation of the gear engagement.

23. The method of claim 21 , wherein the torque jog includes a fluctuation in the torque output of the electric motor above a fixed value or below a fixed value.

24. The method of claim 21 , wherein the torque jog includes a fluctuation in the torque output of the electric motor above and below a fixed value.

25. The method of claim 21 , wherein the vehicle is a bus.

26. The method of claim 21 , wherein the vehicle is a low-floor bus.

27. The method of claim 21 , wherein the fluctuation ends in less than or equal to 500 milliseconds.