VEHICLE GUIDANCE SYSTEM

• US 20120130593A1
• Filed: 06/02/2010
• Published: 05/24/2012
• Est. Priority Date: 06/02/2009
• Status: Active Grant

• Current Assignee: Topcon Precision Agriculture Pty Ltd. (Topcon Corporation)
• Original Assignee: Topcon Precision Agriculture Pty Ltd. (Topcon Corporation)
• Inventors: Davis, Andrew, Di Federico, Ivan, Schildroth, Rhett
• Granted Patent: US 8,892,308 B2
• Time in Patent Office: Days
• US Class Current: 701/41
• CPC Class Codes: A01B 69/008 automatic
• CPC Class Codes: B62D 1/00 Steering controls, i.e. means for initiating a change of direction of the vehicle
• CPC Class Codes: B62D 1/28 non-mechanical , e.g. following a line or other known markers
• CPC Class Codes: B62D 1/286 Systems for interrupting non-mechanical steering due to driver intervention
• CPC Class Codes: B62D 5/04 electrical, e.g. using an electric servo-motor connected to, or forming part of, the steering gear
• CPC Class Codes: B62D 5/0415 the axes being coaxial
• CPC Class Codes: B62D 5/0487 detecting motor faults B62D5/0496 takes precedence

Abstract

A vehicle guidance system is disclosed where the vehicle includes a steering wheel assembly including a steering wheel and a hub, the hub connected to a steering shaft rotatable about a steering wheel axis within a steering column for steering the vehicle. The vehicle guidance system includes a receiver for receiving a position indication signal, a steering controller for generating a steering control signal based on the position indication signal and a drive assembly to directly drive the steering wheel assembly responsive to the steering control signal. The drive assembly generates a torque about a drive axis to rotate the steering wheel assembly, wherein the drive axis of the drive assembly is coaxial to the steering wheel axis.

Claims

1. A vehicle guidance system for a vehicle, the vehicle including a steering wheel assembly including a steering wheel and a hub, the hub connected to a steering shaft rotatable about a steering wheel axis within a steering column for steering the vehicle, the vehicle guidance system including:

a receiver for receiving a position indication signal;

a steering controller for generating a steering control signal based on the position indication signal;

a drive assembly to directly drive the steering wheel assembly responsive to the steering control signal, the drive assembly operable to generate a torque about a drive axis to rotate the steering wheel assembly, wherein the drive axis of the drive assembly is coaxial to the steering wheel axis.

2. The vehicle guidance system of claim 1, wherein the drive assembly directly drives the hub of the steering wheel assembly to rotate the steering wheel assembly.

3. The vehicle guidance system of claim 2, wherein the drive assembly is located adjacent to the hub of the steering wheel.

4. The vehicle guidance system of claim 3, wherein the drive assembly is located below the hub of the steering wheel.

5. The vehicle guidance system of claim 2, wherein the drive assembly is integrated into the hub of the steering wheel.

6. The vehicle guidance system of claim 1, wherein the drive assembly includes an electric motor, the electric motor including a housing, a stator element and a rotor element rotatable within the housing about the drive axis.

7. The vehicle guidance system of claim 6, wherein the rotor element is connected to the hub of the steering wheel assembly.

8. The vehicle guidance system of claim 1, wherein the drive assembly includes an anti-rotation member for providing a steering reaction torque.

9. The vehicle guidance system of claim 8, wherein the anti-rotation member connects the drive assembly to the steering column of the vehicle.

10. The vehicle guidance system of claim 1, wherein the steering wheel assembly and drive assembly are removable as a unit from the steering shaft.

11. A drive assembly for directly driving a steering wheel assembly, the steering wheel assembly including a steering wheel and a hub, the hub connected to a steering shaft rotatable about a steering wheel axis within a steering column for steering the vehicle, wherein the drive assembly generates a torque about a drive axis to rotate the steering wheel assembly and wherein the drive axis of the drive assembly is coaxial to the steering wheel axis.

12. The drive assembly of claim 11, wherein the drive assembly directly drives the hub of the steering wheel assembly to rotate the steering wheel assembly.

13. A method of disengaging a drive assembly in a vehicle guidance system, the vehicle guidance system operable on a steering wheel assembly including a steering wheel and a hub, the hub connected to a steering shaft rotatable about a steering wheel axis within a steering column for steering the vehicle and the drive assembly operable to generate a torque about a drive axis to rotate the steering wheel assembly, wherein the drive axis of the drive assembly is coaxial to the steering wheel axis, the method including the steps of:

commanding the drive assembly to achieve a prescribed value of a performance parameter;

monitoring the drive assembly to determine an actual value of the performance parameter;

determining a difference measure between the prescribed value and the actual value and disengaging the drive assembly based on the difference measure.

14. The method of disengaging a drive assembly as claimed in claim 13, wherein the drive assembly includes an electric motor.

15. The method of disengaging a drive assembly as claimed in claim 14, wherein the performance parameter is electric motor speed.

16. The method of disengaging a drive assembly as claimed in claim 14, wherein the performance parameter is a direction of rotation of the electric motor.

17. The method of disengaging a drive assembly as claimed in claim 14, wherein the performance parameter is electric motor torque.

18. The method of disengaging a drive assembly as claimed in claim 14, wherein the performance parameter is electric motor position.

19. The method of disengaging a drive assembly as claimed in claim 14, wherein the performance parameter is steered wheel angle position.

20. The method of disengaging a drive assembly as claimed in claim 14, wherein the performance parameter is the position of the vehicle.

21. The method of disengaging a drive assembly as claimed in claim 14, wherein the commanded performance parameter and the monitored performance parameter are different.

22. The method of disengaging a drive assembly as claimed in claim 21, wherein the commanded performance parameter is a direction of applied torque and the monitored performance parameter is an acceleration of the electric motor.

23. The method of disengaging a drive assembly as claimed in claim 13, wherein the difference measure is evaluated over a predetermined time period.

24-26. -26. (canceled)

27. An integrated drive assembly and steering wheel assembly for a vehicle, the steering wheel assembly including a steering wheel and a hub, the hub connected to a steering shaft rotatable about a steering wheel axis within a steering column for steering the vehicle, the drive assembly for directly driving the steering assembly by generating a torque about a drive axis to rotate the steering wheel assembly, wherein the drive axis of the drive assembly is coaxial to the steering wheel axis and wherein a physical characteristic of the steering wheel assembly is matched to the drive assembly.

28. The integrated drive assembly and steering wheel assembly of claim 27 wherein the physical characteristic of the steering wheel assembly is its inertial characteristics.