Tactile electronic steering system

• US 20060200291A1
• Filed: 03/07/2006
• Published: 09/07/2006
• Est. Priority Date: 03/07/2005
• Status: Abandoned Application

• Current Assignee: Parker-Hannifin Corporation
• Original Assignee: Parker-Hannifin Corporation
• Inventors: Wroblewski, Anthony J.
• Application Number:
  US11/370,796
• Publication Number:
  US 20060200291A1
• Time in Patent Office: Days
• US Class Current: 701/41
• CPC Class Codes: B62D 6/002 computing target steering angles for front or rear wheels B62D7/159 takes precedence
• CPC Class Codes: B62D 6/008 Control of feed-back to the steering input member, e.g. simulating road feel in steer-by-wire applications

Abstract

A steering control system adjusts steering gain and position of the vehicle wheels based on a rate of change of the steering wheel. The steering control system provides a passive feedback control signal to a passive tactile feedback device. The steering control system provides electronic steering control that is consistent with the feel of a standard hydrostatic steering system.

Claims

1. A vehicle steering system comprising:

a steering device;

a position sensor that senses the position of the steering device; and

a steering controller in operative communication with the steering device and the position sensor, wherein the steering controller;

determines a rate of change of the position of the steering device; and

generates a steering command signal for moving wheels of the vehicle in a desired direction at a desired speed based on the determined rate of change.

2. A steering system according to claim 1, further comprising a tactile feedback device in operative contact with steering device.

3. A steering system according to claim 2, wherein the tactile feedback device is a Theological steering brake.

4. A steering system according to claim 2, wherein the tactile feedback device provides a drag to movement of the steering device in response to a feedback command signal from the steering controller.

5. A steering system according to claim 4, wherein the steering controller determines a feedback command signal based on the rate of change of the position of the steering device.

6. A steering system according to claim 5, wherein the steering controller provides a feedback command signal that increases drag in response to a rate of change above a predetermined threshold.

7. A steering system according to claim 4, further comprising a ground speed sensor, wherein the steering controller determines a feedback command signal based on vehicle speed sensed by the ground speed sensor.

8. A steering system according to claim 7, wherein the steering controller provides a feedback command signal that increases drag in response to an increased ground speed.

9. A steering system according to claim 4, further comprising a steering system pressure sensor, wherein the steering controller determines a feedback command signal based on steering system pressure sensed by the steering system pressure sensor.

10. A steering system according to claim 9, wherein the steering controller provides a feedback command signal that increases drag in response to an increased steering system pressure.

11. A steering system according to claim 4, further comprising a sensor for sensing vehicle wheel position, wherein the steering controller determines a feedback command signal based on the sensed by the sensor for sensing vehicle wheel position.

12. A steering system according to claim 11, wherein the steering controller provides a feedback command signal that increases drag in response to a vehicle wheel position indicative of end of stroke.

13. A steering system according to claim 4, further comprising an operator-adjustable steering drag selector, wherein the steering controller determines a feedback command signal based on the operator-selected steering drag.

14. A steering system according to claim 4, further comprising a steering mode selector that provides on-the-fly selection between steering modes.

15. A steering system according to claim 1, further comprising a hydraulic system that controls vehicle steering based on command signals received from the steering controller.

16. A method of controlling steering in a slow-moving off-highway vehicle, the method comprising:

detecting a position of a steering device;

determining a rate of change of the position of the steering device; and

based on the determined rate of change, generating a steering command signal for moving wheels of the vehicle in a desired direction at a desired speed.

17. A method according to claim 16, further comprising:

providing a feedback command signal to a passive tactile feedback device in communication with the steering device.

18. A method according to claim 16, wherein feedback command signal is provided in response to sensed ground speed, steering system pressure, vehicle wheel position and/or operator-selected steering drag.

19. A steering control system comprising:

a steering controller in operative communication with a steering device and a position sensor that senses the position of the steering device, wherein the steering controller;

determines a rate of change of the position of the steering device; and

generates a steering command signal for moving wheels of the vehicle in a desired direction at a desired speed based on the determined rate of change.

20. The steering control system according to claim 19, wherein the steering controller evaluates steering mode selection before generating the steering command signal.

21. The steering control system according to claim 19, further comprising a tactile feedback device in operative contact with steering device.