Auto-steering apparatus and method

• US 20040210357A1
• Filed: 04/17/2003
• Published: 10/21/2004
• Est. Priority Date: 04/17/2003
• Status: Active Grant

• Current Assignee: Battelle Energy Alliance LLC (Battelle Memorial Institute)
• Original Assignee: Battelle Energy Alliance LLC (Battelle Memorial Institute)
• Inventors: Anderson, Matthew O., McKay, Mark D.
• Granted Patent: US 7,191,061 B2
• Time in Patent Office: Days
• US Class Current: 701/23
• CPC Class Codes: A01B 69/008 automatic
• CPC Class Codes: G05D 1/0278 using satellite positioning signals, e.g. GPS

Abstract

A vehicular guidance method involves providing a user interface using which data can be input to establish a contour for a vehicle to follow, the user interface further configured to receive information from a differential global positioning system (DGPS), determining cross track and offset data using information received from the DGPS, generating control values, using at least vehicular kinematics, the cross track, and the offset data, and providing an output to control steering of the vehicle, using the control values, in a direction to follow the established contour while attempting to minimize the cross track and the offset data.

Claims

1. A vehicular guidance method comprising:

providing a user interface using which data can be input to establish a contour for a vehicle to follow, the user interface further configured to receive information from a differential global positioning system (DGPS);

determining cross track and offset data using information from the DGPS;

generating control values, using at least vehicular kinematics, the cross track and the offset data; and

providing an output to control steering of the vehicle, using the control values, in a direction to follow the established contour while attempting to minimize the cross track and the offset data.

2. The method of claim 1 wherein, the output is configured to control a steering control system of the vehicle.

3. The method of claim 1 wherein, the output is configured to control a D.C. motor configured to be coupled to a steering mechanism of the vehicle.

4. The method of claim 1, further comprising:

sensing steering of the vehicle in a second controller; and

controlling the steering control system to attempt to minimize cross track and offset information.

5. The method of claim 4, further comprising:

determining if a counteracting force in excess of a predetermined threshold is applied to the steering control system and, if so,

disabling control of steering of the vehicle.

6. The method of claim 1 wherein, the automatically steering the vehicle is performed by:

receiving control values from the master controller in a second controller;

configuring the second controller to interface with the steering control system; and

receiving steering commands from the second controller at the steering control system to steer the vehicle.

7. The method of claim 6 wherein, the second controller adjusts vehicular steering, and vehicular turn is computed using the equation:

vehicular turn=R_k*((cross track-RG₁)−

(offset * RG₂))/velocity, where R_k, RG₁, and RG₂ are gains based upon velocity, cross track, and offset.

8. The method of claim 6 wherein, desired turn of a vehicle is computed using the equation:

(vehicular turn * Axle_AD+Axle_mid), where

turn desired=(vehicular turn * Axle_AD+Axle_mid), where

Axle_AD is a conversion constant;

Axle_mid=calibrated value where the vehicle drives straight.

9. The method of claim 3 wherein, output of the D.C. motor is provided by the equation:

(Gain *(desired turn-Axle_POT)), where Axle_POT=read axle position.

10. A vehicular guidance system configured to removably attach to a vehicle, comprising:

a user interface configured to establish a contour for a vehicle to follow, the user interface further configured to receive information from a differential global positioning system (DGPS);

a computer system configured to receive input from the user interface to generate cross track and offset data;

a master controller configured to generate control values, using at least the cross track and the offset data, in order to control the vehicle to follow the established contour; and

second controller configured to interface with the master controller and a steering control system and receiving commands therefrom to control the steering control system in order to control steering of the vehicle, to follow the established contour while attempting to minimize the cross track and offset data.

11. The system of claim 10 wherein, the steering control system comprises a D.C. motor system configured to be coupled to a steering column of the vehicle to retrofit the vehicle without tapping into hydraulic systems of the vehicle.

12. The system of claim 10 wherein, vehicular turn is computed using the equation:

vehicular turn=R_k*((cross track-RG₁)−

(offset * RG₂))/velocity, where R_k, RG₁, and RG₂ are gains based upon velocity, cross track, and offset.

13. The system of claim 10 wherein, a desired turn of a vehicle is computed using the equation:

(turn * Axle_AD+Axle_mid), where

desired turn=(vehicular turn * Axle_AD+Axle_mid), where

Axle_AD is a conversion constant;

Axle_mid=calibrated value where the vehicle drives straight.

14. The system of claim 12 wherein, output of the D.C. motor is determined by the equation:

(Gain *(turn desired-Axle_POT)), where Axle_POT=read axle position.

15. A vehicle guidance system comprising:

a computer system having a user interface, the computer system configured to receive data from a differential global positioning system (DGPS) and reference vehicular contour information from a user, the computer system further configured to generate cross track and offset data; and

a control system configured to removably attach to a vehicle, the control system configured to receive at least vehicular velocity, the cross track and the offset data to generate commands issued to a steering control system to automatically steer the vehicle, to follow the reference vehicular contour.

16. The system of claim 15 wherein, the control system further comprises:

a master controller configured to receive the cross track, offset, and vehicular velocity data; and

a second controller configured to receive commands from the master controller, the second controller issuing commands to the steering control system to steer the vehicle to follow the reference vehicular contour.

17. The system of claim 16 wherein the steering control system comprises a D.C. motor system configured to be coupled to a steering column of the vehicle to retrofit the vehicle without tapping into hydraulic systems of the vehicle.

18. The system of claim 16 wherein, vehicular turn is computed using the equation:

vehicular turn=R_k*((cross track-RG₁)−

(offset * RG₂))/velocity, where R_k, RG₁, and RG₂ are gains based upon velocity, cross track, and offset.

19. The system of claim 16 wherein, a desired turn of a vehicle is computed using the equation:

(turn * Axle_AD+Axle_mid), where

turn desired=(vehicular turn * Axle_AD+Axle_mid), where

Axle_AD is a conversion constant;

Axle_mid=calibrated value where the vehicle drives straight.

20. The system of claim 17 wherein, output of the D.C. motor is determined by the equation:

(Gain *(turn desired-Axle_POT)), where Axle_POT=read axle position.

21. The system of claim 16 wherein, the user interface enables a user to select vehicular contour parameters as well as monitor overall progress of the system.

22. The system of claim 16 wherein, the master controller issues commands to dynamically correct cross track and offset errors based on vehicular kinematics.

23. The system of claim 16 wherein, the master controller causes the vehicle to achieve speeds in excess of 15 mph.

24. A vehicular guidance system comprising:

means for establishing a contour for a vehicle to follow, the means further configured to receive information from a differential global positioning system (DGPS);

means for determining cross track and offset data;

means for generating control values, using at least vehicular kinematics, the cross track and the offset data; and

means for providing an output to control steering of the vehicle, using the control values, in a direction to follow the established contour while attempting to minimize the cross track and offset data.