MODEL BASED VEHICLE OVERSPEED ALGORITHM

• US 20080228366A1
• Filed: 11/28/2007
• Published: 09/18/2008
• Est. Priority Date: 03/16/2007
• Status: Active Grant

• Current Assignee: GM Global Technology Operations LLC (General Motors Company)
• Original Assignee: GM Global Technology Operations Incorporated (General Motors Company)
• Inventors: Lehner, Chad W., Jess, Richard B., Younessi, Bahram, Clutz, Richard H., Hutchinson, Mark T., Howell, William G., Allison, Ronald C.
• Granted Patent: US 8,112,214 B2
• Time in Patent Office: Days
• US Class Current: 701/70
• CPC Class Codes: B60K 31/047 the memory being digital
• CPC Class Codes: B60W 2050/0031 Mathematical model of the vehicle
• CPC Class Codes: B60W 2420/408 Radar; Laser, e.g. lidar
• CPC Class Codes: B60W 2710/0616 Position of fuel or air injector

Abstract

A system for limiting the speed of a vehicle includes a first module that generates a first torque signal based on a vehicle speed, a second module that generates a second torque signal based on a difference between a predetermined vehicle speed limit and the vehicle speed, and a third module that generates an output torque signal based on the first and second torque signals. The output torque signal is adapted to control the output torque of a motor.

Claims

1. A system for limiting the speed of a vehicle, comprising:

a first module that generates a first torque signal based on a vehicle speed;

a second module that generates a second torque signal based on a difference between a predetermined vehicle speed limit and the vehicle speed; and

a third module that generates an output torque signal based on the first and second torque signals, wherein the output torque signal is adapted to control the output torque of a motor.

2. The system of claim 1 wherein at least one of the first and second modules includes a look-up table.

3. The system of claim 1 wherein the third module sums the first and second torque signals to form the output torque signal.

4. The system of claim 3 wherein the second torque signal is negative when the vehicle speed is greater than the vehicle speed limit.

5. The system of claim 3 wherein the second torque signal is positive when the vehicle speed is greater than the vehicle speed limit.

6. The system of claim 1 further comprising the motor.

7. The system of claim 6 wherein the motor is at least one of an internal combustion engine and an electric motor.

9. The method of claim 1 wherein at least one of generating the first torque signal and generating the second torque signal includes employing a look-up table.

10. The method of claim 1 wherein generating the output torque signal includes summing the first and second torque signals to form the output torque signal.

11. The method of claim 3 wherein the second torque signal is negative when the vehicle speed is greater than the vehicle speed limit.

12. The method of claim 3 wherein the second torque signal is positive when the vehicle speed is greater than the vehicle speed limit.

13. The method of claim 6 wherein the motor is at least one of an internal combustion engine and an electric motor.

8. A method for limiting the speed of a vehicle, comprising:

generating a first torque signal based on a vehicle speed;

generating a second torque signal based on a difference between a predetermined vehicle speed limit and the vehicle speed; and

generating an output torque signal based on the first and second torque signals, wherein the output torque signal is adapted to control the output torque of a motor.

14. A speed-limited powertrain for a vehicle, comprising:

a motor that develops torque for propelling the vehicle;

a speed sensor that generates a speed signal based on a speed of the vehicle; and

a control module that generates a torque control signal based on the speed signal, a predetermined maximum speed, and an axle torque of the vehicle, wherein the torque control signal is adapted to control the output torque of the motor and the output torque of the motor is related to the axle torque by a gear ratio.

15. The powertrain of claim 14 wherein the motor is an internal combustion engine.

16. The powertrain of claim 15 further comprising an electronic throttle body that meters combustion air to the internal combustion engine based on the torque control signal.

17. The powertrain of claim 15 wherein the control module varies at least one of a fuel flow rate, a fuel injection timing, and an ignition timing to the internal combustion engine based on the torque control signal.

18. The powertrain of claim 14 wherein the motor is an electric motor.

19. The powertrain of claim 18 wherein the control module varies an amount of electric power that is delivered to the internal combustion engine based on the torque control signal.

20. The powertrain of claim 14 wherein the controller further comprises:

a first module that generates a first torque signal based on the vehicle speed and an aerodynamic drag coefficient of the vehicle a second module that generates a second torque signal based on a difference between the predetermined maximum speed and the vehicle speed signal; and

a third module that generates torque control signal based on a sum of the first and second torque signals.