Object tracking and steer maneuvers for materials handling vehicles

• US 8,731,777 B2
• Filed: 02/23/2011
• Issued: 05/20/2014
• Est. Priority Date: 08/18/2009
• Status: Active Grant

• Current Assignee: Crown Equipment Corporation
• Original Assignee: Crown Equipment Corporation
• Inventors: Castaneda, Anthony T., McCroskey, William W., Schloemer, James F., Schumacher, Mark E., Siefring, Vernon W., Wellman, Timothy A.
• Primary Examiner(s): To, Tuan C.
• Application Number:
  US13/033,169
• Publication Number:
  US 20110166721A1
• Time in Patent Office: 1,182 Days
• Field of Search: 701/2, 701/41, 701/50, 701/301, 340/435, 340/5.2, 706/12, 180/443, 180/446
• US Class Current: 701/41
• CPC Class Codes: B62D 15/0265 Automatic obstacle avoidance by steering
• CPC Class Codes: B62D 6/001 the torque NOT being among the input parameters
• CPC Class Codes: B62D 6/002 computing target steering angles for front or rear wheels B62D7/159 takes precedence
• 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 1/024 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 one or more zones proximate the vehicle, wherein the zones are monitored by a controller associated with the vehicle. The controller tracks objects in the zones via sensor data obtained from at least one obstacle sensor located on the vehicle and via dead reckoning. The objects are tracked by the controller until they are no longer in an environment proximate the vehicle. Different zones result in different steer maneuvers being implemented by the controller.

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 a first object is located in a first zone defined at least partially on a first side of the vehicle;

detecting based on the received sensor data that a second object is located in a second zone defined at least partially on a second side of the vehicle, wherein the second object is closer to a central axis of the vehicle than the first object; and

automatically performing a steer correction maneuver by the controller causing the vehicle to steer toward the first object so as to steer the vehicle away from the second object until at least one of;

the first object enters a predefined portion of the first zone; and

the second object exits a predefined portion of the second zone.

2. The method of claim 1, wherein the predefined portion of the first zone comprises a portion of the first zone wherein further steering of the vehicle toward the first object is determined to not be permitted.

3. The method of claim 1, wherein the predefined portion of the second zone comprises a portion of the second zone wherein further steering of the vehicle away from the second object is determined to not be required.

4. The method of claim 1, further comprising straightening a heading of the vehicle upon at least one of:

the second object exiting the predefined portion of the second zone; and

the first object entering the predefined portion of the first zone.

5. The method of claim 1, further comprising initiating a braking operation if at least one of the first object and the second object enters a portion of its corresponding zone that comprises a stop zone.

6. 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.

7. 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.

8. The method of claim 1, wherein the first and second zones each comprise:

a stop zone, wherein if an object is detected in the stop zone, the vehicle is caused to initiate a braking operation;

a no steer zone laterally outwardly from the stop zone, wherein if an object is detected in at least a portion of the no steer zone the vehicle is not permitted to turn toward the no steer zone in which the object was detected; and

a steer zone laterally outwardly from the no steer zone, wherein if an object is detected in at least a portion of the steer zone the vehicle is permitted to turn toward the steer zone in which the object was detected.

9. The method of claim 8, wherein the predefined portion of the first zone comprises the no steer zone of the first zone.

10. The method of claim 8, wherein the predefined portion of the second zone comprises the steer zone of the second zone.

11. The method of claim 8, wherein the first and second zones each further comprise a hug zone laterally outwardly from the steer zone, wherein the hug zone is usable by the controller to steer the vehicle relative to selected objects detected in the corresponding hug zone such that the vehicle is substantially maintained at a desired distance from the selected object.

12. A method for a materials handling vehicle to automatically implement a steer maneuver comprising:

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

detecting that a selected object is in an environment proximate the vehicle; and

performing a steer maneuver by the controller causing the vehicle to steer such that the vehicle is substantially maintained at a desired distance from the selected object;

wherein performing a steer maneuver comprises;

steering the vehicle such that the selected object is at least partially maintained in a hug zone defined within the environment such that at least a portion of the selected object is substantially maintained on a hug line associated with the hug zone, wherein;

if a laterally innermost portion of the selected object is located laterally between the hug line and the vehicle, the controller automatically causes the vehicle to steer away from the selected object until the laterally innermost portion of the selected object is located on the hug line, at which point the controller automatically causes the vehicle to steer to a desired heading; and

if the laterally innermost portion of the selected object is located laterally on the other side of the hug line than the vehicle, the controller automatically causes the vehicle to steer toward the selected object until the laterally innermost portion of the selected object is located on the hug line, at which point the controller automatically causes the vehicle to steer to the desired heading.

13. The method of claim 12, wherein the desired heading is substantially in the axial direction.

14. The method of claim 12, wherein the hug zone extends in an axial direction that is parallel to a central axis of the vehicle and the hug zone is laterally displaced from a side of the vehicle.

15. The method of claim 12, wherein the environment comprises first and second hug zones, the first hug zone displaced laterally from the left side of the vehicle and the second hug zone displaced from the right side of the vehicle.

16. The method of claim 15, wherein the environment further comprises:

first and second stop zones laterally inwardly from the respective first and second hug zones, wherein if an object is detected in a stop zone, the vehicle is caused to initiate a braking operation;

first and second no steer zones laterally outwardly from the respective stop zones, wherein if an object is detected in at least a portion of a no steer zone the vehicle is not permitted to turn toward the no steer zone in which the object was detected; and

first and second steer zones laterally between the respective no steer zones and the respective hug zones, wherein if an object is detected in at least a portion of a steer zone the vehicle is permitted to turn toward the steer zone in which the object was detected.

17. The method of claim 16, wherein the selected object is the first object that is detected in at least one of the steer zones and the no steer zones.

18. The method of claim 15, wherein the controller is programmable to only perform a steer maneuver if an object is detected in a select one of the first and second hug zones.

19. The method of claim 12, wherein detecting that a selected object is in an environment proximate the vehicle comprises detecting that the selected object is in a scanned zone of the environment, wherein the scanned zone is scanned by the at least one sensing device.

20. The method of claim 12, wherein the selected object is an object that is determined to be the closest object to the vehicle within the environment, as measured in a lateral direction that is perpendicular to a central axis of the vehicle.

21. The method of claim 12, wherein the selected object is the first object that is detected in a scanned zone defined in the environment, wherein the scanned zone is scanned by the at least one sensing device.

22. The method of claim 12, wherein the selected object comprises one of a rack and a stacked product face having a generally axially extending edge portion such that the vehicle is substantially maintained at a desired distance from the edge portion of the rack or stacked product face.

23. A method for a materials handling vehicle to automatically implement a steer maneuver comprising:

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

detecting that a selected object is in an environment proximate the vehicle, the environment comprising;

first and second hug zones, the first hug zone displaced laterally from the left side of the vehicle and the second hug zone displaced from the right side of the vehicle;

first and second stop zones laterally inwardly from the respective first and second hug zones, wherein if the selected object is detected in one of the stop zones, the vehicle is caused to initiate a braking operation;

first and second no steer zones laterally outwardly from the respective first and second stop zones, wherein if the selected object is detected in at least a portion of one of the no steer zones the vehicle is not permitted to turn toward the no steer zone in which the object was detected; and

first and second steer zones laterally between the respective first and second no steer zones and the respective first and second hug zones, wherein if the selected object is detected in at least a portion of one of the steer zones the vehicle is permitted to turn toward the steer zone in which the object was detected; and

performing a steer maneuver by the controller causing the vehicle to steer such that the vehicle is substantially maintained at a desired distance from the selected object.

24. The method of claim 23, wherein the controller is programmable to only perform a steer maneuver if the selected object is detected in a select one of the first and second hug zones.

25. The method of claim 23, wherein detecting that a selected object is in an environment proximate the vehicle comprises detecting that the selected object is in a scanned zone of the environment, wherein the scanned zone is scanned by the at least one sensing device.

26. The method of claim 23, wherein the selected object is an object that is determined to be the closest object to the vehicle within the environment, as measured in the lateral direction perpendicular to a central axis of the vehicle.

27. The method of claim 23, wherein the selected object is the first object that is detected in a scanned zone defined in the environment, wherein the scanned zone is scanned by at least one sensing device.

28. The method of claim 23, wherein the selected object comprises one of a rack and a stacked product face having a generally axially extending edge portion such that the vehicle is substantially maintained at a desired distance from the edge portion of the rack or stacked product face.