System and method for a vehicle accelerator pedal

1. A vehicle comprising:

a chassis;

a prime mover supported by the chassis to propel the vehicle;

an accelerator pedal supported by the chassis, wherein the accelerator pedal moves in a first direction to request additional torque from the prime mover;

a pedal limit connected to a motor and movable towards and away from the accelerator pedal, wherein the pedal limit limits movement of the accelerator pedal in the first direction when the pedal limit is in contact with the accelerator pedal; and

a controller configured to control the motor to move the pedal limit to contact the accelerator pedal in response to receiving an input from a driver to maintain a selected vehicle speed without actuation of the accelerator pedal.

2. The vehicle of claim 1 further comprising a motor drivingly connected to a worm, the worm connected to the pedal limit, wherein the motor translates the worm to move the pedal limit.

3. The vehicle of claim 1 wherein the pedal limit does not inhibit movement of the accelerator pedal in the first direction.

4. The vehicle of claim 1 wherein the accelerator pedal moves away from the pedal limit when the accelerator pedal is moved in the first direction to accelerate the vehicle above the selected vehicle speed.

5. The vehicle of claim 1 wherein the controller is further configured to determine a pedal position as a function of a torque request from the prime mover.

6. The vehicle of claim 5 wherein the controller is further configured to move the pedal limit to contact the accelerator pedal with the accelerator pedal in the pedal position associated with the torque request for the selected vehicle speed.

7. The vehicle of claim 5 wherein the pedal limit is positioned to correspond with a threshold value below the torque request for the selected vehicle speed.

8. A method of controlling a vehicle, the method comprising:

receiving a request from a driver to operate a vehicle in cruise control at a selected vehicle speed;

controlling a prime mover to propel the vehicle at the selected vehicle speed without actuation of an accelerator pedal; and

actuating a pedal limit towards the accelerator pedal to establish contact with the accelerator pedal and maintain the accelerator pedal in a position associated with the selected vehicle speed and limit movement of the accelerator pedal towards an idle position while the vehicle is operating in cruise control.

9. The method of claim 8 further comprising retracting the pedal limit away from the accelerator pedal such that the pedal limit no longer contacts the accelerator pedal in response to receiving another request from the driver to cancel operation of the vehicle in cruise control.

10. The method of claim 8 wherein the pedal limit does not inhibit movement of the accelerator pedal in a first direction indicative of a request for additional torque while the vehicle is operating in cruise control.

11. The method of claim 8 wherein the position of the pedal is determined using a drivetrain torque required to meet the selected vehicle speed.

12. The method of claim 8 further comprising moving the pedal limit to a second position while the vehicle is operating in cruise control in response to a request from the driver to alter the selected vehicle speed without actuating the accelerator pedal.

13. The method of claim 8 further comprising moving the pedal limit to a second position while the vehicle is operating in cruise control in response to a change in an external load on the vehicle.

14. The method of claim 8 wherein the position of the accelerator pedal indicates a torque request that is a threshold value below a torque of the prime mover required to meet the selected vehicle speed.

15. The method of claim 8 further comprising measuring the position of the pedal limit using a sensor.

16. The method of claim 15 further comprising commanding the pedal limit to retract away from the accelerator pedal if a measured position of the pedal limit differs from the position associated with the selected vehicle speed across a time interval.

17. The method of claim 15 further comprising setting the measured position of the accelerator pedal as the idle position for the prime mover if the measured position of the pedal limit differs from the position associated with the selected vehicle speed across a time interval.

18. The method of claim 17 further comprising disabling cruise control for selection by the driver and disabling actuation of the pedal limit in response to setting the measured position of the accelerator pedal as the idle position for the prime mover.

19. An accelerator pedal system for a vehicle, the system comprising:

an accelerator pedal movable in a first direction to request additional torque from a prime mover;

a spring biasing the accelerator pedal in a second direction opposite to the first direction;

a pedal limit connected to a motor and movable towards and away from the accelerator pedal, wherein the pedal limit limits movement of the accelerator pedal in the first direction when the pedal limit is in contact with the accelerator pedal; and

a controller configured to control the motor to move the pedal limit to a first position in contact with the accelerator pedal in response to receiving a cruise control input from a driver to maintain a selected vehicle speed without actuation of the accelerator pedal.

20. The system of claim 19 wherein the controller is further configured to determine a position of the accelerator pedal using a prime mover torque required to meet the selected vehicle speed, and control the motor to move the pedal limit to a second position while the vehicle is operating in cruise control in response to a request from the driver to alter the selected vehicle speed without actuation of the accelerator pedal thereby adjusting a range of motion of the accelerator pedal.