Steer control maneuvers for materials handling vehicles

• US 8,577,551 B2
• Filed: 10/13/2011
• Issued: 11/05/2013
• Est. Priority Date: 08/18/2009
• Status: Active Grant

• Current Assignee: Crown Equipment Corporation
• Original Assignee: Crown Equipment Corporation
• Inventors: Siefring, Vernon W., Corbett, Michael
• Primary Examiner(s): To, Tuan C.
• Application Number:
  US13/272,337
• Publication Number:
  US 20120078471A1
• Time in Patent Office: 754 Days
• Field of Search: 701/2, 701/41, 180/443, 180/446
• US Class Current: 701/41
• CPC Class Codes: B62D 15/0265 Automatic obstacle avoidance by steering
• CPC Class Codes: B66F 9/063 Automatically guided
• CPC Class Codes: B66F 9/0755 Position control; Position detectors
• CPC Class Codes: B66F 9/07568 Steering arrangements
• CPC Class Codes: B66F 9/07581 Remote controls
• CPC Class Codes: G05D 1/0033 by having the operator tracking the vehicle either by direct line of sight or via one or more cameras located remotely from the vehicle
• CPC Class Codes: G05D 1/024 in combination with a laser lasers per se H01S
• CPC Class Codes: G05D 1/0255 using acoustic signals, e.g. ultra-sonic singals sonar systems designed for anti-collision purposes G01S15/93
• CPC Class Codes: G08C 17/02 using a radio link
• CPC Class Codes: G08C 2201/20 Binding and programming of remote control devices

Abstract

A materials handling vehicle automatically implements steer maneuvers when objects enter an environment around the vehicle. A steer correction maneuver is automatically performed by steering the vehicle away from the detected object, wherein an angle of steer correction and/or a rate of change of the steering angle that is implemented to achieve a desired angle of steer correction is dependent upon how far from a reference coordinate associated with the vehicle the detected object is determined to be.

Claims

1. A method for a materials handling vehicle to automatically perform a steer correction maneuver comprising:

receiving sensor data from at least one sensing device by a controller on a materials handling vehicle;

detecting based on the received sensor data that an object is located in an environment monitored by the controller, the environment comprising an area around the vehicle;

determining how far the detected object is from a reference coordinate associated with the vehicle; and

automatically performing a steer correction maneuver by steering the vehicle away from the detected object, wherein an angle of steer correction is dependent upon how far from the reference coordinate the detected object is determined to be.

2. The method of claim 1, wherein the angle of steer correction is:

a first angle when an object is determined to be in an outer region that comprises a furthest region from the reference coordinate;

a second angle greater than the first angle when an object is determined to be in a middle region closer to the reference coordinate than the outer region; and

a third angle greater than the second angle when an object is determined to be in an inner region closer to the reference coordinate than the middle region.

3. The method of claim 1, wherein the angle of steer correction varies dynamically dependent upon how far from the reference coordinate the detected object is determined to be.

4. The method of claim 1, wherein automatically performing a steer correction maneuver comprises automatically performing the steer correction maneuver while the materials handling vehicle is traveling in response to receiving a wirelessly transmitted travel request by a corresponding wireless transmitter.

5. The method of claim 1, wherein receiving sensor data from at least one sensing device comprises receiving the sensor data from a scanning laser device.

6. The method of claim 1, wherein the reference coordinate is a central axis of the vehicle.

7. The method of claim 1, wherein the environment is defined by:

a front edge that is displaced a predefined distance from front of the vehicle;

a rear edge that is located at a predetermined location associated with the vehicle;

a left edge that is displaced a predefined distance from a central axis of the vehicle; and

a right edge that is displaced a predefined distance from the central axis of the vehicle.

8. The method of claim 1, wherein the environment defines a plurality of action zones that result in the controller implementing different steer maneuvers for each action zone, such that, depending on the action zone that a tracked object enters, the controller automatically implements a steer maneuver corresponding to the entered action zone.

9. The method of claim 1, wherein a rate of change of the steering angle that is implemented to achieve the angle of steer correction is dependent upon how far from the reference coordinate the detected object is determined to be.

10. A method for a materials handling vehicle to automatically perform a steer correction maneuver comprising:

receiving sensor data from at least one sensing device by a controller on a materials handling vehicle;

detecting based on the received sensor data that an object is located in an environment monitored by the controller, the environment comprising an area around the vehicle;

determining how far the detected object is from the vehicle; and

automatically performing a steer correction maneuver by steering the vehicle away from the detected object, wherein an angle of steer correction is dependent upon how far from the vehicle the detected object is determined to be.

11. The method of claim 10, wherein the angle of steer correction is:

a first angle when an object is determined to be in an outer region that comprises a furthest region from the vehicle;

a second angle greater than the first angle when an object is determined to be in a middle region closer to the vehicle than the outer region; and

a third angle greater than the second angle when an object is determined to be in an inner region closer to the vehicle than the middle region.

12. The method of claim 10, wherein the angle of steer correction varies dynamically dependent upon how far from the vehicle the detected object is determined to be.

13. The method of claim 10, wherein automatically performing a steer correction maneuver comprises automatically performing the steer correction maneuver while the materials handling vehicle is traveling in response to receiving a wirelessly transmitted travel request by a corresponding wireless transmitter.

14. The method of claim 10, wherein receiving sensor data from at least one sensing device comprises receiving the sensor data from a scanning laser device.

15. The method of claim 10, wherein the environment is defined by:

a front edge that is displaced a predefined distance from front of the vehicle;

a rear edge that is located at a predetermined location associated with the vehicle;

a left edge that is displaced a predefined distance from a central axis of the vehicle; and

a right edge that is displaced a predefined distance from the central axis of the vehicle.

16. The method of claim 10, wherein the environment defines a plurality of action zones that result in the controller implementing different steer maneuvers for each action zone, such that, depending on the action zone that a tracked object enters, the controller automatically implements a steer maneuver corresponding to the entered action zone.

17. The method of claim 10, wherein a rate of change of the steering angle that is implemented to achieve the angle of steer correction is dependent upon how far from the vehicle the detected object is determined to be.

18. A method for a materials handling vehicle to automatically perform a steer correction maneuver comprising:

receiving sensor data from at least one sensing device by a controller on a materials handling vehicle;

detecting based on the received sensor data that an object is located in an environment monitored by the controller, the environment comprising an area around the vehicle;

determining how far the detected object is from a reference coordinate associated with the vehicle; and

automatically performing a steer correction maneuver by steering the vehicle away from the detected object, wherein a rate of change of the steering angle that is implemented to achieve a desired angle of steer correction is dependent upon how far from the reference coordinate the detected object is determined to be.

19. The method of claim 18, wherein the rate of change of the steering angle that is implemented to achieve the desired angle of steer correction is:

a first amount when an object is determined to be in an outer region that comprises a furthest region from the reference coordinate;

a second amount greater than the first amount when an object is determined to be in a middle region closer to the reference coordinate than the outer region; and

a third amount greater than the second amount when an object is determined to be in an inner region closer to the reference coordinate than the middle region.

20. The method of claim 18, wherein the rate of change of the steering angle that is implemented to achieve the desired angle of steer correction varies dynamically dependent upon how far from the reference coordinate the detected object is determined to be.

21. The method of claim 18, wherein automatically performing a steer correction maneuver comprises automatically performing the steer correction maneuver while the materials handling vehicle is traveling in response to receiving a wirelessly transmitted travel request by a corresponding wireless transmitter.

22. The method of claim 18, wherein receiving sensor data from at least one sensing device comprises receiving the sensor data from a scanning laser device.

23. The method of claim 18, wherein the reference coordinate is a central axis of the vehicle.

24. The method of claim 18, wherein the environment is defined by:

a front edge that is displaced a predefined distance from front of the vehicle;

a rear edge that is located at a predetermined location associated with the vehicle;

a left edge that is displaced a predefined distance from a central axis of the vehicle; and

a right edge that is displaced a predefined distance from the central axis of the vehicle.

25. The method of claim 18, wherein the environment defines a plurality of action zones that result in the controller implementing different steer maneuvers for each action zone, such that, depending on the action zone that a tracked object enters, the controller automatically implements a steer maneuver corresponding to the entered action zone.

26. The method of claim 18, wherein:

the desired angle of steer correction is dependent upon how far from the reference coordinate the detected object is determined to be;

the rate of change of the steering angle that is implemented to achieve the desired angle of steer correction varies dynamically dependent upon how far from the reference coordinate the detected object is determined to be; and

the desired angle of steer correction varies dynamically dependent upon how far from the reference coordinate the detected object is determined to be.