Follower vehicle control system and method for forward and reverse convoy movement

• US 8,275,491 B2
• Filed: 01/13/2012
• Issued: 09/25/2012
• Est. Priority Date: 08/20/2008
• Status: Active Grant

• Current Assignee: Autonomous Solutions, Inc.
• Original Assignee: Autonomous Solutions, Inc.
• Inventors: Ferrin, Jeffrey L., Thayn, Brett, Hornberger, Michael
• Primary Examiner(s): Zanelli, Michael J.
• Application Number:
  US13/350,404
• Publication Number:
  US 20120123641A1
• Time in Patent Office: 256 Days
• Field of Search: None
• US Class Current: 701/1
• CPC Class Codes: G05D 1/0227 using mechanical sensing means, e.g. for sensing treated area
• CPC Class Codes: G05D 1/0272 comprising means for registering the travel distance, e.g. revolutions of wheels measuring distance traversed on the ground by vehicles, e.g. using odometers G01C22/00
• CPC Class Codes: G05D 1/0278 using satellite positioning signals, e.g. GPS
• CPC Class Codes: G05D 1/0295 by at least one leading vehicle of the fleet

Abstract

A vehicle control system for causing a follower vehicle to follow a leader may have a tether system mounted to the follower vehicle. The tether system may include a tether having an end adapted to be attached to the leader, a length sensor, and an angle sensor. A path tracking system operatively associated with the tether system determines a path traveled by the leader. A path control system operatively associated with the path tracking system and the follower vehicle causes the follower vehicle to follow the path traveled by the leader. A spacing control system operatively associated with the path tracking system and the follower vehicle causes the follower vehicle to maintain a predetermined spacing between the follower vehicle and the leader.

Claims

1. A vehicle control system for causing a follower vehicle to follow a leader, comprising:

a tether system operatively associated with a leader and a follower vehicle, the tether system comprising;

a tether, the tether having a first end adapted to be attached to the leader and a second end adapted to be attached to the follower vehicle;

a length sensor operatively associated with the tether, the length sensor sensing a length of the tether extending between the follower vehicle and the leader; and

an angle sensor operatively associated with the tether, the angle sensor sensing an angle between the tether and the follower vehicle;

a path tracking system operatively associated with the tether system, the path tracking system determining a path traveled by the leader;

a path control system operatively associated with the path tracking system, the path control system causing the follower vehicle to travel to a traveled point on the path traveled by the leader; and

a direction control system operatively associated with the follower vehicle and the tether system, the direction control system selecting between a forward travel direction and a reverse travel direction for the follower vehicle based on a change in length of the tether.

2. A vehicle control system for causing a follower vehicle to follow a leader, comprising:

a tether system mounted to the follower vehicle, the tether system comprising;

a tether having an end adapted to be attached to the leader;

a length sensor operatively associated with the tether, the length sensor sensing a length of the tether extending between the follower vehicle and the leader; and

an angle sensor operatively associated with the tether, the angle sensor sensing an angle between the tether and the follower vehicle;

a path tracking system operatively associated with the tether system, the path tracking system determining a path traveled by the leader;

a path control system operatively associated with the path tracking system and the follower vehicle, the path control system determining a determined path for the follower vehicle from an actual position of the follower vehicle and a selected travel point on the path traveled by the leader, the path control system causing the follower vehicle to follow the determined path for the follower vehicle; and

a spacing control system operatively associated with the path tracking system and the follower vehicle, the spacing control system causing the follower vehicle to maintain a predetermined spacing between the follower vehicle and the leader.

3. The system of claim 2, wherein the path control system provides a desired curvature to the follower vehicle, the desired curvature causing the follower vehicle to follow the path traveled by the leader.

4. The system of claim 2, wherein the spacing control system causes the follower vehicle to maintain a predetermined spacing between the follower vehicle and the leader, the predetermined spacing being measured along the path traveled by the leader.

5. The system of claim 4, wherein the spacing control system provides desired velocity to the follower vehicle, the desired velocity causing the follower vehicle to maintain the predetermined spacing.

6. The system of claim 2, further comprising a direction control system operatively associated with the follower vehicle and the tether system, the direction control system selecting between a forward travel direction and a reverse travel direction for the follower vehicle based on a change in length of the tether.

7. The system of claim 2, further comprising a damper operatively associated with the angle sensor.

8. The system of claim 2, wherein the tether system further comprises:

a spool mounted for rotation with respect to the tether system, the spool holding a length of the tether;

a motor operatively connected to the spool, the motor rotating the spool to pay-out and reel-in the tether; and

a tether guide operatively associated with the motor, the spool, and the tether.

9. The system of claim 2, wherein the path control system causing the follower vehicle to follow the determined path for the follower vehicle occurs automatically.

10. A vehicle control system for causing a follower vehicle to follow a leader, comprising:

a tether mounted to the follower vehicle, the tether having an end adapted to be attached to the leader;

a length sensing means operatively associated with the tether for sensing a length of the tether extending between the follower vehicle and the leader;

an angle sensing means operatively associated with the tether for sensing an angle between the tether and the follower vehicle;

a path tracking system operatively associated with the length sensing means and the angle sensing means, the path tracking system determining a path traveled by the leader;

a path control system operatively associated with the path tracking system and the follower vehicle, the path control system determining a determined path for the follower vehicle from an actual position of the follower vehicle and a selected travel point on the path traveled by the leader, the path control system causing the follower vehicle to follow the determined path for the follower vehicle; and

a spacing control system operatively associated with the path tracking system and the follower vehicle, the spacing control system causing the follower vehicle to maintain a predetermined spacing between the follower vehicle and the leader.

11. The system of claim 10, further comprising a tension control means operatively associated with the tether for controlling a tension in the tether.

12. The system of claim 11, wherein the tension control means varies the tension in the tether as a function of a velocity of the leader.

13. A method for causing a follower vehicle to follow a leader, comprising:

connecting the follower vehicle to the leader with a tether;

measuring a length of the tether connecting the follower vehicle to the leader;

measuring an angle between the tether and the follower vehicle;

determining a position of the leader based on the measured length and the measured angle;

determining a path traveled by the leader based on a plurality of determined leader positions;

determining a determined path for the follower vehicle from an actual position of the follower vehicle and a selected travel point on the path traveled by the leader;

steering the follower vehicle so that the follower vehicle substantially follows the determined path for the follower vehicle; and

controlling a velocity of the follower vehicle so that the follower vehicle maintains a predetermined distance from the leader.

14. The method of claim 13, wherein controlling a velocity of the follower vehicle comprises controlling a velocity of the follower vehicle so that the follower vehicle maintains a predetermined distance from the leader, the predetermined distance being measured along the path traveled by the leader.

15. The method of claim 14, wherein the predetermined distance is a function of the velocity of the leader.

16. The method of claim 14, further comprising:

operating the follower vehicle in a reverse travel direction; and

steering the follower vehicle in the reverse travel direction based on the measured angle between the tether and the follower vehicle.

17. The method of claim 14, further comprising selecting to operate the follower vehicle in either a forward travel direction or a reverse travel direction for the follower vehicle based on a change in length of the tether.

18. The method of claim 13, further comprising:

operating the follower vehicle in a reverse travel direction; and

steering the follower vehicle in the reverse travel direction to follow in reverse at least a portion of the path traveled by the leader.