Traction control method for a tracked vehicle

• US 20070179698A1
• Filed: 01/17/2006
• Published: 08/02/2007
• Est. Priority Date: 01/17/2006
• Status: Active Grant

• Current Assignee: Allison Transmission Incorporated (Allison Transmission Holdings Incorporated)
• Original Assignee: GM Global Technology Operations LLC (General Motors Company)
• Inventors: Oehme, Clifford
• Granted Patent: US 8,061,459 B2
• Time in Patent Office: Days
• US Class Current: 701/82
• CPC Class Codes: B60T 11/21 with two pedals operating on respective circuits, pressures therein being equalised when both pedals are operated together, e.g. for steering steering non-deflectable wheels or endless tracks by differentially driving ground-engaging elements on opposite vehicle sides using brakes as main steering effecting means B62D11/08
• CPC Class Codes: B62D 11/003 Electric or electronic control systems

Abstract

The present invention provides a traction control method for a tracked vehicle such as a military tank. The method includes calculating a track proportionality factor and a vehicle proportionality factor based on predefined attributes of the tracked vehicle. A minimum turn radius of the tracked vehicle is calculated based on the velocity of the tracked vehicle, the maximum coefficient of friction between the tracks of the tracked vehicle and the ground (0.7), and gravitational acceleration (9.80665 m/s2). A sprocket rotational speed is calculated based on the pitch diameter of the tracked vehicle sprockets and the velocity of the tracked vehicle. Based on the preceding calculations, the method of the present invention calculates a required track speed differential configured to turn the tracked vehicle at the minimum turn radius. If a commanded turn radius is less than the minimum turn radius, the track speed differential of the tracked vehicle is limited to the required track speed differential to prevent the tracked vehicle from slipping.

Claims

1. A traction control method for a tracked vehicle comprising:

calculating a minimum turn radius of the tracked vehicle;

calculating a required track speed differential configured to turn the tracked vehicle at the minimum turn radius;

determining if a commanded turn radius is less than the minimum turn radius; and

limiting the track speed differential of the tracked vehicle to the required track speed differential if the commanded turn radius is less than the minimum turn radius such that the tracked vehicle does not slip.

2. The traction control method of claim 1, wherein said calculating a required track speed differential includes determining a track proportionality factor.

3. The traction control method of claim 1, wherein said calculating a required track speed differential includes determining a vehicle proportionality factor.

4. The traction control method of claim 1, wherein said calculating a required track speed differential includes determining a relationship between a sprocket rotational speed and a vehicle speed of the tracked vehicle.

5. The traction control method of claim 1, wherein said calculating a required track speed differential includes determining a sprocket rotational speed.

6. The traction control method of claim 1, further comprising executing the commanded turn radius if the commanded turn radius is greater than or equal to the minimum turn radius.

7. The traction control method of claim 1, further comprising identifying a maximum coefficient of friction between the tracked vehicle and the ground.

8. The traction control method of claim 1, further comprising measuring a track length of the tracked vehicle.

9. The traction control method of claim 1, further comprising measuring a track center distance of the tracked vehicle.

10. A traction control method for a tracked vehicle comprising:

determining a track proportionality factor;

determining a vehicle proportionality factor using said track proportionality factor;

calculating a minimum turn radius of the tracked vehicle;

calculating a required track speed differential using said vehicle proportionality factor and said minimum turn radius, said required track speed differential being configured to turn the tracked vehicle at the minimum turn radius;

determining if a commanded turn radius is less than the minimum turn radius; and

limiting the track speed differential of the tracked vehicle to the required track speed differential if the commanded turn radius is less than the minimum turn radius such that the tracked vehicle does not slip.

11. The traction control method of claim 10, wherein said calculating a required track speed differential includes determining a relationship between a sprocket rotational speed and a vehicle speed of the tracked vehicle.

12. The traction control method of claim 10, wherein said calculating a required track speed differential includes determining a sprocket rotational speed.

13. The traction control method of claim 10, further comprising executing the commanded turn radius if the commanded turn radius is greater than or equal to the minimum turn radius.

14. The traction control method of claim 10, further comprising identifying a maximum coefficient of friction between the tracked vehicle and the ground.

15. The traction control method of claim 10, further comprising measuring a track length of the tracked vehicle.

16. The traction control method of claim 10, further comprising measuring a track center distance of the tracked vehicle.

17. A traction control method for a tracked vehicle comprising:

determining a track proportionality factor;

determining a vehicle proportionality factor using the track proportionality factor;

calculating a minimum turn radius of the tracked vehicle;

determining a sprocket rotational speed;

calculating a required track speed differential using the vehicle proportionality factor, the minimum turn radius, and the sprocket rotational speed, said required track speed differential being configured to turn the tracked vehicle at the minimum turn radius;

determining if a commanded turn radius is less than the minimum turn radius;

executing the commanded turn radius if the commanded turn radius is greater than or equal to the minimum turn radius; and

limiting the track speed differential of the tracked vehicle to the required track speed differential if the commanded turn radius is less than the minimum turn radius such that the tracked vehicle does not slip.

18. The traction control method of claim 17, further comprising identifying a maximum coefficient of friction between the tracked vehicle and the ground.

19. The traction control method of claim 17, further comprising measuring a track length of the tracked vehicle.

20. The traction control method of claim 17, further comprising measuring a track center distance of the tracked vehicle.