OBJECT TRACKING AND STEER MANEUVERS FOR MATERIALS HANDLING VEHICLES

• US 20130297151A1
• Filed: 06/10/2013
• Published: 11/07/2013
• 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., Schumacher, Mark E., Siefring, Vernon W., Wellman, Timothy A.
• Granted Patent: US 9,002,581 B2
• Time in Patent Office: Days
• 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 tracking objects detected by at least one sensing device on a materials handling vehicle, the method comprising:

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

data representative of whether an object is detected in a scanned zone that is scanned by the at least one sensing device, the scanned zone being a part of an environment in which objects are tracked; and

data representative of a lateral distance that any detected objects are from a reference coordinate associated with the vehicle;

wherein each detected object is tracked until the object is no longer located in the environment by;

assigning the object to at least one bucket defined within the scanned zone by the at least one sensing device; and

using at least one of subsequent sensor data and dead reckoning to re-assign the object to adjacent buckets and to determine an updated lateral distance that the object is from the reference coordinate as the vehicle moves; and

wherein the controller automatically implements a steer correction maneuver if a tracked object enters a steer away zone defined within the environment.

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

3. 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.

4. The method of claim 3, wherein the environment comprises:

the scanned zone, which extends;

in an axial direction rearwardly from the front edge of the environment to a predetermined axial location, wherein the axial direction is parallel to the central axis of the vehicle; and

in the lateral direction from a left predetermined location to a right predetermined location, the left predetermined location being between the left side of the truck and the left edge of the environment and the right predetermined location being between the right side of the truck and the right edge of the environment; and

a history zone that includes;

a first portion that extends laterally from the scanned zone to the left edge of the environment and extends laterally from the scanned zone to the right edge of the environment; and

a second portion that extends rearwardly from the scanned zone to the rear edge of the environment.

5. The method of claim 4, wherein the at least one sensing device scans for objects located in the scanning zone and does not scan for objects in the history zone.

6. The method of claim 5, wherein:

objects located in the scanning zone are tracked using the sensor data from the at least one sensing device and dead reckoning; and

once objects that have been detected by the at least one sensing device exit the scanned zone and enter the history zone, the objects are tracked using only dead reckoning.

7. The method of claim 6, wherein the scanned zone comprises a plurality of scan zones, each scan zone comprises a plurality of buckets, the buckets located adjacent to one another in the axial direction.

8. The method of claim 7, wherein the history zone comprises a plurality of buckets located adjacent to one another in the axial direction such that objects being tracked in the history zone during movement of the vehicle are re-assigned to adjacent buckets using dead reckoning so as to update the axial distance of the object relative to the vehicle.

9. 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.