Systems and methods for order-picking

• US 20060255951A1
• Filed: 05/15/2006
• Published: 11/16/2006
• Est. Priority Date: 05/13/2005
• Status: Active Grant

• Current Assignee: EMS Technologies, Inc. (Honeywell International Inc.)
• Original Assignee: EMS Technologies, Inc. (Honeywell International Inc.)
• Inventors: Sorenson, Richard W. Jr., Roeder, William H., Runyon, Donald L., Clott, Michael Sayre
• Granted Patent: US 7,639,142 B2
• Time in Patent Office: Days
• US Class Current: 340/572.700
• CPC Class Codes: B62B 3/06 for simply clearing the load from the ground masted lift trucks B66F
• CPC Class Codes: B62B 5/0096 Identification of the cart or merchandise, e.g. by barcodes or radio frequency identification [RFID]
• CPC Class Codes: B66F 9/0755 Position control; Position detectors
• CPC Class Codes: B66F 9/12 Platforms; Forks; Other load supporting or gripping members
• CPC Class Codes: G06K 7/0008 General problems related to the reading of electronic memory record carriers, independent of its reading method, e.g. power transfer
• CPC Class Codes: G06K 7/10079 the collision being resolved in the spatial domain, e.g. temporary shields for blindfolding the interrogator in specific directions
• CPC Class Codes: G06K 7/10336 the antenna being of the near field type, inductive coil
• CPC Class Codes: G06Q 10/087 Inventory or stock management, e.g. order filling, procurement or balancing against orders
• CPC Class Codes: H01Q 1/22 by structural association with other equipment or articles
• CPC Class Codes: H01Q 1/2216 used in interrogator/reader equipment
• CPC Class Codes: H01Q 13/22 Longitudinal slot in boundary wall of waveguide or transmission line H01Q13/203 takes precedence
• CPC Class Codes: H01Q 9/0421 with a shorting wall or a shorting pin at one end of the element H01Q9/0414 takes precedence

Abstract

In one exemplary embodiment in accordance with the invention, an order-picking system includes a picking cart having a radio frequency (RF) antenna arranged above an object-stacking surface of the picking cart. The order-picking system further includes a radio frequency identification (RFID) tag reader coupled to the RF antenna. The RFID tag reader is configured to identify a first RFID tag attached to a first tagged object placed on the picking cart and further configured to eliminate identification of a second RFID tag attached to a second tagged object located outside a perimeter of the object-stacking surface of the picking cart.

Claims

1. An order-picking system, comprising:

a picking cart having a radio frequency (RF) antenna arranged above an object-stacking surface of the picking cart; and

a radio frequency identification (RFID) tag reader coupled to the RF antenna, the RFID tag reader configured to identify a first RFID tag attached to a first tagged object placed on the picking cart and further configured to eliminate identification of a second RFID tag attached to a second tagged object located outside a perimeter of the object-stacking surface of the picking cart.

2. The order-picking system of claim 1, wherein the RF antenna is a phased array antenna.

3. The order-picking system of claim 2, wherein the second tagged object is located inside a picking area and the phased array antenna is configured to suppress RF coverage of the picking area.

4. The order-picking system of claim 2, wherein the second tagged object is located inside a picking area and the phased array antenna is configured to provide an RF null in the picking area.

5. The order-picking system of claim 2, wherein the phased array antenna is operable to steer an RF null from a first location located outside the perimeter of the object-stacking surface of the picking cart to a second location located outside the perimeter of the object-stacking surface of the picking cart.

6. The order-picking system of claim 2, wherein the phased array antenna is operable to steer RF coverage from a first portion of an object-stacking surface of the picking cart to a second portion of the object-stacking surface of the picking cart.

7. The order-picking system of claim 2, wherein the phased array antenna is operable to provide a first near-field focus on at least a portion of the object-stacking surface of the picking cart.

8. The order-picking system of claim 7, wherein the phased array antenna is further operable to provide a second near-field focus that is located above the object-stacking surface of the picking cart.

9. The order-picking system of claim 2, wherein the phased array antenna is operable to provide RF coverage of a first portion of an object-stacking surface of the picking cart and further configured to suppress RF coverage of a second portion of the object-stacking surface of the picking cart.

10. The order-picking system of claim 1, further comprising:

a range finder coupled to the RFID tag reader, the range finder configured to measure distance between a radiating surface of the RF antenna and an external surface of the first tagged object placed on the picking cart.

11. The order-picking system of claim 10, wherein the range finder is one of a) a laser range finder, b) an ultrasonic range finder, and c) a radio frequency range finder.

12. The order-picking system of claim 1, further comprising:

a weighing system coupled to the RFID tag reader, the weighing system configured to measure a weight of the first tagged object placed on the picking cart.

13. The order-picking system of claim 12, wherein the weighing system is further configured to measure a differential weight between the first tagged object and a second tagged object placed on the picking cart.

14. The order-picking system of claim 1, further comprising:

a motion detector coupled to the RFID tag reader, the motion detector configured to detect at least one of a forward motion and a reverse motion of the picking cart.

15. The order-picking system of claim 1, wherein the picking cart is one of a) a lift truck, b) a motorized pallet truck, c) a hand pallet truck, d) a shopping cart, e) a trailer, and f) a flatbed.

16. A method for order-picking, the method comprising:

reading a first radio frequency identification (RFID) tag attached to a first tagged object placed on a picking cart; and

eliminating reading of a second RFID tag attached to a second tagged object located outside a perimeter of an object-stacking surface of the picking cart.

17. The method of claim 16, wherein eliminating reading of the second RFID tag comprises:

configuring a phased array antenna beam pattern to provide radio frequency (RF) coverage at a first location inside the perimeter of the object-stacking surface of the picking cart; and

suppressing RF coverage at a second location outside the perimeter of the object-stacking surface of the picking cart.

18. The method of claim 17, further comprising steering the phased array antenna beam pattern from the first location to a second location inside the perimeter of the object-stacking surface of the picking cart.

19. The method of claim 17, wherein suppressing RF coverage at the second location comprises providing an RF null at the second location.

20. The method of claim 19, further comprising steering the RF null from the second location outside the perimeter of the object-stacking surface of the picking cart to a third location outside the perimeter of the object-stacking surface of the picking cart.

21. The method of claim 16, wherein reading the first RFID tag comprises configuring a phased array antenna beam pattern to provide a near-field focus upon one of a) at least a portion of the object-stacking surface of the stacking cart and b) a location above the object-stacking surface of the stacking cart.

22. The method of claim 16, wherein reading the first RFID tag comprises:

providing a phased array antenna; and

obtaining range information between a radiating surface of the phased array antenna and a top surface of the first tagged object.

23. A method for order-picking using a radio frequency identification (RFID) tag reader mounted on a picking cart, the method comprising:

setting a validation period for validating placement of an object upon the picking cart;

directing a first RFID interrogation signal during the validation period towards an object-stacking surface of the picking cart;

receiving in response thereof, a first RFID code from a first RFID tag;

directing a second RFID interrogation signal during the validation period towards the object-stacking surface of the picking cart;

receiving in response thereof, a second RFID code from a second RFID tag;

identifying the first RFID tag to be same as the second RFID tag upon detecting the first RFID code to be same as the second RFID code;

identifying the first RFID tag to be different than the second RFID tag upon detecting the first RFID code to be different than the second RFID code;

upon identifying the first RFID tag to be same as the second RFID tag, storing one of the first and second RFID codes in an RFID database configured to store at least one RFID code of a picked object placed on the picking cart; and

upon identifying the first RFID tag to be different than the second RFID tag, preventing storage of the first RFID code in the RFID database and further preventing storage of the second RFID code in the RFID database.

24. The method of claim 23, wherein the first RFID interrogation signal is directed towards the object-stacking surface of the picking cart at the start of the validation period and the second RFID interrogation signal is directed towards the object-stacking surface of the picking cart at the end of the validation period.

25. A method for order-picking using a radio frequency identification (RFID) tag reader mounted on a picking cart, the method comprising:

setting a validation period for validating placement of a first object upon the picking cart;

performing during the validation period, a plurality of RFID interrogations;

setting a confidence factor for a plurality of RFID responses generated thereto;

using the confidence factor and the plurality of RFID responses to validate RFID tag data obtained from a first RFID tag attached to the first object;

storing in a database thereon, RFID tag data obtained from the first RFID tag;

performing after the validation period, at least one RFID interrogation; and

retaining in the database, RFID tag data of the first object after the at least one RFID interrogation.

26. The method of claim 25, wherein the first RFID tag is irresponsive to the at least one RFID interrogation.

27. The method of claim 25, wherein RFID tag data is obtained from a second RFID tag attached to a second object during the at least one RFID interrogation.

28. The method of claim 27, wherein the second object is located on top of the first object in the picking cart and wherein the first RFID tag is irresponsive to the at least one RFID interrogation.

29. The method of claim 27, wherein the second object is located external to the picking cart.

30. The method of claim 29, wherein the first RFID tag is responsive to the at least one RFID interrogation.

31. An order-picking program stored on a computer-readable medium, the program comprising:

logic configured to control a phased array antenna for directing RF radiation towards an object-stacking surface of a picking cart and suppressing RF radiation upon a location outside a perimeter of the object-stacking surface of the picking cart; and

logic configured to obtain RFID tag information from a first RFID tag attached to a first tagged object that is an item located in the picking cart.

32. The order-picking program of claim 31, wherein logic configured to control the phased array antenna comprises logic configured to steer the RF radiation of the phased array antenna.

33. The order-picking program of claim 31, wherein suppressing RF radiation upon the location outside the perimeter of the object-stacking surface of the picking cart comprises providing a null at the location.

34. The order-picking program of claim 31, wherein logic configured to control the phased array antenna comprises logic configured to change a near-field focus of the RF radiation of the phased array antenna.

35. The order-picking program of claim 34, wherein changing the near-field focus comprises obtaining ranging information.

36. The order-picking program of claim 31, further comprising:

logic configured to eliminate RFID information obtained from a second RFID tag attached to a second RFID object that is an item not located in the picking cart.

37. A method for order-picking using a radio frequency identification (RFID) tag reader mounted on a picking cart, the method comprising:

reading a first radio frequency identification (RFID) tag attached to a first tagged object; and

measuring a change in weight imposed upon an object-stacking surface of the picking cart.

38. The method of claim 37, further comprising:

validating the reading of the first RFID tag when the change in weight is equal to a weight gain; and

storing in a database of the tag reader, upon validating of the reading, first ID data obtained by reading the first RFID tag.

39. The method of claim 38, further comprising:

invalidating the reading of the first RFID tag when the change in weight is equal to zero.