VARIABLE OFFSET POSITIONING ANTENNA ARRAY FOR ENHANCED GUIDANCE OF AUTOMATED GUIDED VEHICLES (AGVS)

• US 20100185353A1
• Filed: 01/15/2010
• Published: 07/22/2010
• Est. Priority Date: 01/17/2009
• Status: Active Grant

• Current Assignee: Volley Automation, Inc.
• Original Assignee: Boomerang Systems Incorporated
• Inventors: Barwick, Stott, Petersen, John A.M., Beeny, Lance, Swasey, Merin
• Granted Patent: US 8,494,703 B2
• Time in Patent Office: Days
• US Class Current: 701/23
• CPC Class Codes: B60K 17/30 the ultimate propulsive elements, e.g. ground wheels, being steerable
• CPC Class Codes: B62D 5/0418 Electric motor acting on road wheel carriers
• CPC Class Codes: B62D 7/026 characterised by comprising more than one bogie, e.g. situated in more than one plane transversal to the longitudinal centre line of the vehicle
• CPC Class Codes: E04H 6/00 Buildings for parking cars, rolling-stock, aircraft, vessels or like vehicles, e.g. garages
• CPC Class Codes: E04H 6/183 without transverse movement of the car after leaving the transfer means
• CPC Class Codes: E04H 6/245 without transverse movement of the wheeled parking platform after leaving the transfer means
• CPC Class Codes: E04H 6/305 using car-gripping transfer means
• CPC Class Codes: E04H 6/36 characterised by use of freely-movable dollies
• CPC Class Codes: G05D 1/0265 using buried wires
• CPC Class Codes: G05D 1/0297 by controlling means in a control room
• CPC Class Codes: Y10T 29/49826 Assembling or joining

Abstract

A Variable Offset Positioning Antenna Array for Enhanced Guidance of Automated Guided Vehicles (AGVs) in automated warehousing or storage systems for automobiles or the like, includes two or more inductor coils producing output as a result of interaction with a guidance wire located in or near the surface of the floor which is energized by a frequency generator, and an on board programmable microprocessor which processes the coil output to determine an exact position of the antenna array relative to the guidance wire. In one embodiment, the antenna array enables an AGV to follow a guidance wire at an offset to the direction of travel in order to allow automated storage and retrieval systems to handle asymmetrical items, such as automobiles, more efficiently and cost effectively by decreasing the building space required for travel aisles, vertical conveyors and storage locations as well as decreasing total individual item processing time.

Claims

1. A variable offset positioning antenna array for an automated guided vehicle (AGV) that is adapted to follow a guide wire having a frequency, comprising:

a) two or more inductor coils that each generate an output based on a strength of the frequency sensed at each coil; and

b) a programmable microprocessor that processes the output from each coil to determine a position of the antenna array relative to the guide wire;

c) wherein the position of the antenna array may be dynamically offset relative to the guide wire.

2. The antenna array of claim 1, further adapted to simultaneously follow multiple guide wires having the same or differing frequencies to determine data regarding the direction of travel, speed, position, or orientation of an AGV incorporating the antenna array.

3. The antenna array of claim 1, further comprising the use of the antenna array to dynamically adjust and precisely control the amount of offset in a travel path followed by an AGV equipped with the antenna array down a travel aisle, onto a vertical conveyor, into a storage area, or into a loading area relative to the guide wire.

4. The antenna array of claim 1, further comprising a front antenna array and a rear antenna array incorporated into an AGV and controlled by a control system to simultaneously provide guidance information to an AGV guidance and control system for steering and guidance of the AGV.

5. The antenna array of claim 1, further comprising the use of one or more additional pairs of antenna arrays on an AGV to determine the location of the AGV relative to a multiple-axis guide wire grid.

6. The antenna array of claim 1, wherein the microprocessor determines a position of the AGV relative to the guide wire in an off-wire situation.

7. The antenna array of claim 1, further comprising a control system for enabling the AGV to carry a load in multiple offset positions relative to the guide wire and the direction of travel.

8. The antenna array of claim 1, wherein the guide strip is either a RF wire or magnetic strip.

9. The antenna array of claim 1, wherein the output from the inductor coils comprises:

a) determining two largest output signals out of all of the output signals;

b) determining indexes of two inductor coils that output the two largest output signals;

c) determining if the two inductor coils that output the two largest output signals are adjacent; and

d) computing a position value using an offset value, a relative position value between the two inductor coils, and a coil separation distance.

10. The antenna array of claim 9, wherein computing the position value further comprises:

a) determining a maximum signal out of the two largest output signals;

b) if the index of an inductor coil that outputs the maximum signal is bigger than the index of an indicator coil that outputs the other largest output signal, the position value is computed as follows;

position value=offset−

d/2+RelPos;

otherwise the position value is computed as follows;

position value=offset−

d/2+RelPos, wherein d is the coil separation distance, and RelPos is relative position value between the two inductor coils.

11. The antenna array of claim 10, wherein the offset value is computed by multiplying the coil separation distance by a CoilPair parameter, wherein the CoilPair parameter is set to be the minimum value of the indexes of the two indicator coils.

12. The antenna array of claim 11, wherein the relative position value is computed by multiplying the coil separation distance by a SignalPercentage value, wherein the SignalPercentage value is the ratio between the maximum output signal and the sum of the two largest output signals.

13. An automated guided vehicle (AGV) adapted to follow a guide wire or the like, the AGV comprising at least one antenna in communication with a master control system and having a programmable microprocessor that enables the AGV to dynamically assume a linear, angular or skewed offset position relative to the guide wire or the like in accordance with instructions provided by the control system.

14. The automated guided vehicle of claim 13, further adapted to travel in a diagonal orientation relative to a plurality of parallel and perpendicular guide wires arranged in an X-axis and Y-axis orientation respectively.

15. The automated guided vehicle of claim 13, further comprising a plurality of omni-directional drive and steering systems.

16. An automated storage system for storing a plurality of objects in storage locations, the automated storage system comprising a master control computer, a guide wire network, and a plurality of automated guided vehicles (AGVs) each having an onboard microprocessor and a receiver for receiving control commands from the master control computer, wherein each AGV can dynamically assume an offset position relative to the guide wire network in accordance with instructions provided by the master control computer.

17. The system of claim 16, wherein the storage locations are determined based on a dimensional analysis of the objects.

18. The system of claim 16, wherein the storage locations are variably defined and populated based on a dimensional analysis of the objects.

19. The system of claim 16, wherein the plurality of AGVs are adapted to simultaneously acquire and move multiple objects at a time.

20. The system of claim 16, further comprising the use of trays for the transport and storing of objects.

21. An automated storage system for storing a plurality of storage lockers in storage locations, the automated storage system comprising a master control computer, a guidance network such as a guide wire network, a plurality of storage lockers, and a plurality of automated guided vehicles (AGVs) each having an onboard microprocessor and a receiver for receiving control commands from the master control computer, wherein each AGV can deliver a storage locker from a loading location to a storage location and dynamically assume an offset position relative to the guide wire network during transport of the storage locker.