WO2007144167A2

WO2007144167A2 - System and method for handling objects using sensors to trigger processing of rfid response signals

Info

Publication number: WO2007144167A2
Application number: PCT/EP2007/005238
Authority: WO
Inventors: Walter Rosenbaum; Jörn Brütt; Heinz-Peter Peters; Kai Ramadhin; Lothar Becker; Daniel Evers
Original assignee: Siemens Aktiengesellschaft
Priority date: 2006-06-16
Filing date: 2007-06-14
Publication date: 2007-12-21
Also published as: WO2007144167A3

Abstract

A system for handling objects provided with electronic ID devices (2) includes a sensor unit (4) and an antenna unit (6). The sensor unit (4) has at least one first pressure sensor (24) and at least one stress sensor (26). The pressure sensor (24) is configured to be positioned at an inner area of an operator's finger and to generate a first signal when pressure is applied to the at least one first pressure sensor (24). The stress sensor (26) is configured to be positioned at an outer area of the operator's hand and to generate a second signal when subjected to stress. The antenna unit (6) is configured to emit a polling signal and to receive a response signal from an electronic ID device (2) within reach of the polling signal. The antenna unit (6) is further configured to couple to the sensor unit (4) to be triggered as a function of the first signal and the second signal.

Description

SYSTEM AND METHOD FOR HANDLING OBJECTS USING SENSORS TO TRIGGER PROCESSING OF RFID RESPONSE SIGNALS

BACKGROUND OF THE INVENTION The various embodiments described herein generally relate to systems for handling objects. More particularly, the various embodiments relate to a system and method for obtaining and processing information on the objects. The various embodiments relate further to tools used in such a system.

Exemplary handling systems are used at airports or at mail processing sites. At airports, for example, check-in personnel applies a bar-coded luggage tag to each luggage piece that is used to track, log and/or authenticate the luggage piece in an effort to improve the productivity and reliability of luggage handling, but also to reduce the cost of airline baggage reconciliation. Critical are in particular security related cross-checks of individual checked luggage pieces and confirmation that the baggage handlers manually transfer the luggage pieces into the correct aircraft, or the correct ULDs (Unit Load Device), or trolleys, prior to loading the luggage pieces into an aircraft. A baggage handler is instructed to read the destination airport printed on a luggage tag and to transfer the luggage piece into the appropriate aircraft or ULD. Similarly, at a mail processing site, trays, sacks and parcels are identified by human-readable information (e.g., destination city) that is used to track and trace the trays, sacks and parcels to improve the intralogistics and distribution. Based on the human-readable information, a mail handler is instructed to load, for example, a sack onto a certain van. Where manual handling of such items is part of the tracking process, mishandling of items occurs, e.g., loading into the wrong ULD or van. To improve the tracking and tracing of items, electronic identification devices, such as radio frequency identification tags (hereinafter referred to as RFID tags), can be applied to such items. JP 2005263471 discloses an RFID tag applied to a luggage piece, whereas details as to radio frequency tagging of luggage are described in ISO 18000-6 B₁C and IATA Recommended Practice RP1740c. WO 2006/012997 discloses an RFID tag applied to a tray for postal items. The general RFID application in the area of mail processing and operational problems encountered therein are described in Postal Technology Magazine, March 2006, page 31.

To interact with RFID tags on objects, Mary Catherine O'Connor, Intel Demos RFID-Enabled Projects, RFID Journal, May 17, 2004, accessed on www.rfidjournal.com, describes a fingerless glove with an RFID reader mounted to the top of the hand. The reader includes an antenna/reader board, a transceiver and a rechargeable battery. Similarly, JP2002347937 discloses a glove having an antenna for reader/writer communication with an RFID tag, means for emitting a confirmation sound, and an ON/OFF switch for the reader/writer communication.

U.S. Patent No. 6,097,301 discloses an RFID system that allows adjusting the two-way communication range to assist an operator to individually handle and interrogate a plurality of RFID tagged objects such as suitcases. The operator carries a battery-operated RFID interrogator transceiver attached to a belt worn around the operator's waist. The RFID interrogator includes an antenna, a transmitter, a receiver, a control circuit and a memory. The antenna can be mounted on the operator's hand, wrist or forearm. Interrogation of an RFID tag starts when an RFID tag is within a set proximity of the antenna, or when triggered by the operator.

US 2006/0044112 discloses an RFID system for wearing on the body of a user having an RFID reader in form of a glove and a hat. The RFID reader includes RFID electronics and an antenna to receive data from an RFID tag. A network controller of the system is coupled to the RFID reader for receiving the data received by the RFID reader. The network controller communicates further with an external network. As one type of hand covering, the reader is a fingerless, palmless glove having RFID electronics and an antenna situated to rest in use at the back of the operator's hand.

A general problem of using RFID tags and RFID readers is transmission collision that may occur when the RFID reader comes into too close a contact with several RFID tags, and these RFID tags all respond to the emitted RFID reader signal. The mentioned hand-mounted RFID readers are intended to minimize the problem of transmission collision since the distance between the antenna and the RFID tag is reduced. In addition, the above U.S. Patent No. 6,097,301 teaches to automatically reduce the power when multiple RFID tags are detected until only one RFID tag response remains. This power reduction function, however, adds to the complexity of the system. Handling objects is labor intensive and involves a variety of different hand movements. For example, an operator may grab a large and/or heavy object with two hands, or an object such as a suitcase single-handedly on its handle, whereas the operator may grab a small and/or lightweight object with the fingers only. Although the above hand-mounted RFID readers reduce the distance between the antenna and the RFID tags to minimize transmission collision, these RFID readers are believed to be unsuitable for easy and reliable use during object handling requiring different hand movements and their bulk limits operator dexterity.

SUMMARY OF THE INVENTION

Accordingly, a need exists for an improved way of handling objects provided with RFID tags, in particular in a dynamic and unconstrained environment. As object handling is a strenuous task in itself, any tool provided for this task should be comfortable to wear by an operator and not degrade an operator's dexterity, or otherwise interfere with the labor intensive activity of handling objects, in particular since such a tool is likely to be used for an extended time during a regular work day.

Accordingly, one aspect involves a system for handling objects provided with electronic identification (ID) devices that includes a sensor unit and an antenna unit. The sensor unit has at least one first pressure sensor and at least one stress sensor. The at least one first pressure sensor is configured to be positioned at an inner area of an operator's finger and to generate a first signal when pressure is applied to the at least one first pressure sensor. The at least one stress sensor is configured to be positioned at an outer area of the operator's hand and to generate a second signal when subjected to stress. The antenna unit is configured to emit a polling signal and to receive a response signal from an electronic ID device within reach of the polling signal. The antenna unit is further configured to couple to the sensor unit to be triggered as a function of the first signal and the second signal.

Another aspect involves a method of handling objects provided with electronic ID devices. An operator is provided with at least one sensor unit and an antenna unit coupled to the sensor unit. The at least one sensor unit has at least one first pressure sensor and at least one stress sensor, wherein the at least one first pressure sensor is positioned at an inner area of an operator's finger to generate a first signal when pressure is applied, and wherein the at least one stress sensor is positioned at an outer area of the operator's hand to generate a second signal when subjected to stress. The method determines if the at least one first pressure sensor generates the first signal, and if the at least one stress sensor generates the second signal. The antenna unit is triggered as a function of the first and second signals to start processing a received response signal originating from an electronic ID device. The processing includes obtaining information stored on the electronic ID device. A further aspect involves a sensor unit for a system for handling objects that are provided with electronic ID devices. At least one first pressure sensor is secured to a support to be positioned at an inner area of an operator's finger, and at least one stress sensor is secured to the support to be positioned at an outer area of the operator's hand. The at least one first pressure sensor is configured to generate a first signal when pressure is applied to the at least one first pressure sensor. The at least one stress sensor is configured to generate a second signal when subjected to stress.

The sensor unit senses hand grasps during activities that characterize normal industrial, distribution and heavy item manipulation, like baggage handling or the like, where the lift is mainly by fingers without substantially involving the palm. Advantageously, the sensor unit is immune to "false alarms" caused by normal hand positioning such as resting the palm on ones hip.

According to one embodiment, the information obtained from the RFID tag is used to retrieve a record from a database. At least one characteristic of an object is identified by means of the retrieved record, e.g., destination of the object, passenger status. It is determined if the at least one characteristic is consistent with a predetermined characteristic, e.g., destination of an airplane or van. If consistency exists, e.g., because the destinations match, a confirmation signal is generated. However, if consistency does not exist, an alarm signal is generated.

According to another embodiment, the locations of a plurality of containers within a handling zone are determined. The operator is tracked, e.g., via GPS or triangulation, to determine at least one location of the operator while the antenna unit is triggered due to the operator grasping an object. Tracking the operator is terminated when the object is released by the operator, and a final location of the operator is determined. The final location is compared with the locations of the plurality of containers to determine a container closest to the operator's final location.

The closest container is identified as the container the operator deposits the object.

Advantageously, the various embodiments described herein coordinates all aspects of an RFID reading process, and thereby applications such as baggage reconciliation with exceedingly high reliability. The reading process is also consistent with normal user dexterity for such applications as baggage handling, industrial, intralogistics and distribution settings. Further, the various embodiments described herein allow coordination of RFID tag reading, tracking, logging and authentication on an item by item basis knowing with certainty that a given RFID tag response signal relates to a specific item under consideration. The various embodiments described herein are suitable for a broad range of tracking, logging and/or authentication processes that enable various applications such as airline baggage reconciliation, postal tray and sack handling operations, and inventory tracking and intralogistics. In particular for baggage reconciliation, the operator "time & motion" steps around the labor intensive steps of baggage handling between a conveyor or chute, ULD and aircraft hold (for example, bulk loading) remain unaltered. In general, the overall baggage handling ergonomics, workflow efficiency and ability to gather further information for work balancing are improved.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS The novel features and method steps characteristic of the invention are set out in the claims below. The invention itself, however, as well as other features and advantages thereof, are best understood by reference to the detailed description, which follows, when read in conjunction with the accompanying drawings, wherein:

Fig. 1 shows a schematic illustration of one embodiment of a system using RFID technology to assist the handling of objects provided with RFID tags;

Figs. 2a - 2c show one embodiment of a sensor unit; Fig.3 shows another embodiment of a sensor unit; Fig. 4 shows one embodiment of an antenna unit worn by an operator;

Fig. 5 shows one embodiment of the system of Fig. 1 for determining the position of the operator with respect to containers to be loaded; and

Fig. 6 shows one embodiment of the system of Fig. 1 for initializing RFID tags.

DETAILED DESCRIPTION OF THE INVENTION

Fig. 1 shows a schematic illustration of one embodiment of a system in which a wireless technology is used to assist the handling of objects 8 provided with O electronic identification (ID) devices 2. The wireless technology is in one embodiment the RFID technology and the electronic ID devices 2 are RFID tags. Hereinafter, the electronic ID devices 2 are referred to as RFID tags 2. The system includes a hand- mounted sensor unit 4 and an antenna unit 6. In addition, the system includes in the illustrated embodiment a database 12 coupled to a processor and transceiver unit 14 for communication with the antenna unit 6. In the illustrated embodiment, the antenna unit 6 is carried by the operator 10 when handling objects 8.

The database 12 and the processor and transceiver unit 14 may be located remote from the operator 10, as depicted in Fig. 1. Alternatively, the database 12 and the processor and transceiver unit 14 may be carried by the operator 10, e.g., in a housing worn around, for example, the waist, and may be coupled to the antenna unit 6. In yet another embodiment, the database 12 and the processor and transceiver unit 14 may be part of the antenna unit 6. Further, the functionality of the processor and transceiver unit 14 may be split into a separate processor unit and a separate transceiver unit, which may be mounted and arranged as described above. The database 12 stores a variety of data related to the operator's task(s), for example, related to the baggage tag on each luggage piece being loaded for a flight, and may include flight destination, passenger status, travel class, etc., or in postal and intralogistics applications the next stage in processing for a tray or item. Although Fig. 1 depicts only one sensor unit 4 worn on one hand of the operator 10, it is contemplated that in another embodiment the operator 10 may wear two sensor units 4, one on each hand. Further, the operator 10 may wear a headset 22 having a microphone and a speaker, or may have a barcode reader (not shown) available for use, if required. The object 8 may be a luggage piece (e.g., a suitcase), a mail sack or tray, or any other object an operator 10 typically grabs with at least one hand. In the following description of several embodiments, the object 8 is mainly a luggage piece (unless otherwise stated) that is subject to airport handling, aircraft loading and airline luggage reconciliation. For illustrative purposes, Fig. 1 shows a suitcase to be grabbed by the operator 10 and loaded onto a conveyor 16 or a transport container 18, which is hereinafter also referred to as ULD 18. For certain applications, the container 18 may be equipped with a communication unit 20 for communication with the antenna unit 6, as described below. The communication unit 20 may be configured for RFID communication, infrared communication or wireless beacon communication. However, it is contemplated that the various embodiments described herein are not limited to airline and airport luggage handling. Accordingly, in another embodiment, the object 8 may be a mail sack or mail tray to be loaded by the operator 10 onto the conveyor 16 or the transport container 18 (e.g., van). Furthermore, the object 8 may be any object that is subject to heightened security (e.g., value transports) or seamless recordation of its handling, e.g., for insurance reasons.

The RFID tag 2 is a conventional electronic ID tag based on known RFID technology for which various applications are known. The RFID tag 2 may be affixed to the object 8 as a sticky tag, or may be embedded in a label typically attached to the object 8, for example, as standard airline baggage tag. For example, the airline baggage tag is outwardly identical to current airline check-in counter practice, but contains the RFID tag 2 embedded, or affixed as a separate RFID tag patch. The RFID tag 2 stores an identification number that may be related to a database record. Depending on a particular application, the RFID tag 2 may further store information related to the object 8 that carries that RFID tag 2. For an airport application, for example, the information may include passenger name, flight number, flight destination, etc. For a postal application, for example, the information may include the destination city or country of a mail sack, or the complete or partial destination address of a parcel. In mail handling or similar operations, the RFID tag 2 may be embedded in a tray, attached to a removable tray label, or integral to the label. As is known in the art, this information may be written to the RFID tag 2 during a passenger check-in procedure, after the first reading of a parcel's destination address, or when the destination of a mail sack is known. Briefly, as to the operation of one embodiment of the system, the antenna unit

6 continuously transmits a polling signal, and receives a response signal from any RFID tag 2 that is within reach of the polling signal. As known in the art, the RFID tag 2 emits a signal in response, which the antenna unit 6 detects. The antenna unit 6 disregards the response signal until the operator 10 grabs an object 8. As soon as the operator 10 grabs the object 8, the sensor unit 4 detects that activity and sends a sensor signal to the antenna unit 6. Upon receipt of the sensor signal, the antenna unit 6 begins processing of the response signals based on the assumption that, now that the operator 10 grabs an object 8, one of the response signals originates from the RFID tag 2 of the grabbed object 8, that this RFID tag 2 is closest to the antenna unit 6, and, hence, emits a response signal that causes a high signal strength in the antenna unit 6. The antenna unit 6 selects the strongest response signal as originating from the grabbed object 8. The selection by the antenna unit 6 may be augmented by determining a signal pattern indicative of movement in proximity to the antenna unit 6 as the object 8 transits in the operator's grasp toward the ULD 18. The antenna unit 6 forwards the selected response signal to the processor and transmitter unit 14 for a variety of tracking, logging and/or authentication processes that enable applications such as airline baggage reconciliation, RFID tag initialization, postal tray and sack handling operations, inventory tracking and intralogistics. According to another embodiment of the system, the antenna unit 6 emits a polling signal only when the operator 10 grabs an object 8. That is, the sensor signal generated when the operator 10 grabs the object 8 triggers the antenna unit 6 to start polling any RFID tag 2 within reach of the polling signal. Based on time and motion associated with the application and operational environment involved, the polling can be initiated after a pre-specified time delay after the sensor unit 4 indicates retention of an object 8. Before such an event, the antenna unit 6 is inactive. While the operator 10 grabs the object 8, the response signal emitted from the object's RFID tag 2 coincides with the sensor signal, and is likely the strongest response signal received while the operator 10 grabs the object 8 consistent with the signal pattern mentioned above. The processor then evaluates that response signal. As soon as the operator 10 releases the object 8 the sensor signal, and, hence, the polling terminate.

Sensor Unit Figs. 2a - 2c illustrate exemplary embodiments of the sensor unit 4. The sensor unit 4 includes at least one pressure sensor 24, at least one stress sensor 26 and an interface unit 28 coupled to the sensors 24, 26. In the illustrated embodiment, the sensors 24, 26 are mounted to a support 30 having a glove-like configuration that secures the sensors 24, 26 to the operator's hand and holds them in place during use. The support 30 may be made of an elastic fabric that is permeable for air and moisture for improved comfort. The elastic material allows the operator to easily insert a hand and to move the fingers, yet snuggly secures the sensors 24, 26.

However, it is contemplated that the sensor unit 4 is not limited to the illustrated glove-like configuration of the support 30, and that the sensor unit 4 may have any other configuration that secures the sensors 24, 26 to the operator's hand and holds them in place during use. For example, the support 30 may be shaped similar to a pool/billiard glove that covers the thumb, the middle finger, the index finger, and parts of the palm and the back of the hand. In such an embodiment, the sensors 24, 26 are secured to at least one of the middle and index fingers.

The interface unit 28 is for coupling the sensors 24, 26 to the antenna unit 6. This coupling may occur via wire or wireless. Accordingly, the interface unit 28 may include a cable connector or a transmitter unit for wireless communication, e.g., according to the Bluetooth® standard. As shown in the embodiment of Fig. 2a, the sensor unit 4 includes four pressure sensors 24 that the support 30 secures to the inner sides of four fingers (upper fingers sometimes referred to as "digits"). In the illustrated embodiment, no pressure sensor is assigned to the thumb, although it is contemplated that in another embodiment at least one of the sensors 24, 26 is assigned to the thumb. However, it is contemplated that less than four fingers are provided with pressure sensors 24. In one embodiment, wires 32 that run along the palm area connect each pressure sensor 24 to the interface unit 28. The pressure sensors 24 are positioned so that pressure is applied to at least one of them as soon as the operator 10 grabs, for example, a handle of a suitcase. As shown in the embodiment of Fig. 2b, the sensor unit 4 includes four stress sensors 26 that the support 30 secures to the outer sides of four fingers, preferable over the knuckles or finger joints, or both. Again, in the illustrated embodiment, no stress sensor is assigned to the thumb, and less than four fingers may be provided with stress sensors 26. In one embodiment, wires 34 that run along the back of the hand connect each stress sensor 26 to the interface unit 28. The stress sensors 26 are positioned so that at least one of them is subjected to stress as soon as the operator 10 closes the hand, for example, when grabbing a handle of a suitcase.

In the illustrated embodiment, the wires 32, 34 connect the sensors 24, 26 to the interface unit 28. However, it is contemplated that in other embodiments, the sensors 24, 26 couple to the interface unit 28, or to the antenna unit 6 via a wireless connection.

Each stress sensor 26 may be configured to extend only over a knuckle or a finger joint. In another embodiment, a stress sensor 26 may be configured long enough to extend over both a knuckle and a finger joint. In a further embodiment, a stress sensor 26 may be configured as a two-part unit, one part for a knuckle and one part for a finger joint, as depicted in Fig. 2b.

The sensors 24, 26 used in the sensor unit 4 are in one embodiment transducers that convert a mechanical load (pressure or tension) to an electrical signal. For example, the sensors 24, 26 may be based on a piezoelectric material that generates a voltage upon deformation. The generated voltage is then interpreted as a sensor signal. A piezoelectric material is commercially available, for example, from Morgan Electro Ceramics, or CTS Corporation.

In the embodiment shown in Fig. 2c, the operator grabs the handle of a suitcase. In that situation, the handle presses against at least one pressure sensor 24, whereas each bent finger tensions the respective stress sensor 26. In one embodiment, the sensor unit 4 is considered to be engaged only when both the pressure and stress sensors 24, 26 are concurrently activated. However, it is contemplated that in certain situations less than the four pressure sensors 24, or less than the four stress sensors 26 may be subject to a load. To consider such situations, the sensor unit 6 may be configured to be engaged when, for example, two pressure sensors 24 and two stress sensors 26 generate signals. These sensors 24, 26 respond when the operator 10 grasps, for example, the handle of the suitcase, where the main grasping effort typically involves the foremost part of the hand and where the fingers are drawing upward in a partial clench. At this instance in time the operator's sensor unit 4 invokes the antenna unit 6 to begin processing at least one response signal received from the RFID tag 2. If no response signal is received, for example, due to a missing or damaged RFID tag 2, the operator 10 is notified to that effect and may be instructed to add an auxiliary RFID tag, as described below. The degree of stress required to register as a flex of the sensor unit 4 is determined with respect to predetermined threshold characteristics of the sensor unit 4. When both the pressure sensors 24 and the stress sensors 26 simultaneously exceed first and second threshold values, respectively, an object 8 is deemed to be grasped by the operator 10. In one embodiment, the processing of at least one response signal received from the object's RFID tag 2 commences after a predetermined delay sufficient to remove the object 8 from the proximity of any other RFID tagged luggage, and when based on normal time and motion of baggage handling the object 8 and the RFID tag 2 are in direct line of sight and within centimeter range of the antenna unit 6. The response signal of that RFID tag 2 generates in the antenna unit 6 a response signal above a given threshold and/or signal variation properties consistent with transit of the RFID tagged object 8 being swung after its grasp from, for example, a conveyor outlet, across the anatomical region of a waist mounted antenna unit 6 and into a juxtapositioned ULD 18. Accordingly, the RFID tag's signal is selected as originating from the grabbed object's RFID tag 2.

Fig. 3 illustrates a further embodiment of a sensor unit 4, which includes in addition to the sensors 24, 26 shown in Figs. 2a - 2c an upper palm-area pressure sensor 36. The support 30 is configured to secure the palm-area pressure sensor 36 to an area of the palm in proximity of the operator's wrist. Like the other sensors 24,

26, the sensor 36 is coupled to the interface unit 28 and configured to generate a sensor signal when a third threshold value set for the pressure sensor 36 is exceeded. This sensor unit 4, therefore, has sensors for three different hand areas.

As discussed above, the handling of objects involves a variety of hand movements so that the operator 10 may be equipped with two sensor units 4. During the operator's manual transfer of objects 8 from an outlet to a conveyor, van, ULD or trolley, on occasion two hands are required without necessarily a hand grasp. In such a situation, both sensor units 4 indicate simultaneous interaction with the object 8. During such a two-hand transfer of an object 8, the operator 10 likely places the object 8 and with it the RFID tag 2 essentially center and forward of the operator 10. For example, the operator 10 may press with both hands against the object 8 so that the palm-area pressure sensor 36 of each sensor unit 4 generates a signal, but the pressure and stress sensors 24, 26 may not. Alternatively, the operator 10 may press with one hand and grasp with the other, or grasp with both hands. These activities are interpreted as a two-hand transfer of an object 8.

Antenna Unit

Fig. 4 illustrates one embodiment of an antenna unit 6 worn by the operator 10 at the waist. The antenna unit 6 may be attachable to a belt, incorporated to a belt or worn as a vest-like body wear. In another embodiment, the antenna unit 6 is mounted to a wall, ceiling or any other structure within an object-handling zone to be triggered by the sensor unit 4.

As mentioned above, the antenna unit 6 is coupled to the interface unit 28 of each sensor unit 4 to receive signals generated by the pressure and stress sensors 24, 26 and the pressure sensors 36, if available. In the embodiment of Fig. 4, the operator 10 is equipped with two sensor units 4.

The antenna unit 6 includes a processing unit to process the sensor signals generated by the sensor unit 4. The antenna unit 6 includes further an antenna, and RFID electronics to transmit a polling signal and to receive response signals. As mentioned above, the antenna unit 6 may be configured to emit a polling signal continuously, or only when activated by the sensor unit 4. Depending on a particular application, the antenna unit 6 may be configured to communicate with the processor and transceiver unit 14 or the headset 22, or both, which are shown in Fig. 1. The antenna unit 6 may be contained in a housing to be worn at the operator's waist, for example, in front. As the operator 10 likely handles the object 8 while it is in front or at a side of the operator 10, the communication between the object's RFID tag 2 and the antenna unit 6 is minimally obstructed.

In another embodiment, the antenna unit 6 has two or more active array elements referred to as segments 38. In Fig. 4, the antenna unit 6 has three segments 381, 38r, 38c worn by the operator 10, who is shown as facing the reader, around the waist on left, right and center locations. Each antenna segment 38I, 38r, 38c controls and creates a separate unidirectional field of radiation for polling an RFID tag 2. When more than one of the antenna segments 38I, 38r, 38c are invoked in unison they increase the radiation field for polling the RFID tags 2 accordingly, but allow further to determine which response signal relates to the currently grabbed object's RFID tag 2 by noting signal strength changes as the object 8 and the RFID tag 2 transit relative to the operator's body.

In one embodiment, the unambiguous identification of an RFID tag's response signal is aided by the sensor unit 4. Under the control of the sensor unit 4, i.e., in consideration of when and how (with one or both hands) the operator 10 grabs the object 8, the antenna unit 6 selectively invokes the appropriate segment 38I, 38r, 38c. This provides a restricted field of radiation for polling the RFID tags 2.

In one embodiment, an antenna segment 38I, 38r - right or left - is only energized when that side's sensor-unit equipped hand is engaged. In another embodiment, when the environment adjacent to the grasping hand (e.g., right hand) is very dense with tagged objects 8 (like objects arriving for ULD loading via a conveyor outlet or carrousel), the antenna segment 38I (opposite the grabbing hand) can be used along with the antenna segment 38c to detect an unambiguous response from the RFID tag 2 as the object 8 transits into the ULD 18. During such transit, the object 8 first enters the radiation field of the antenna segment 38c, and subsequently that of the antenna segment 38I. In another embodiment, only the antenna segment 38I is used. Those RFID tagged objects 8 placed previously in the ULD 18 are known and can be ignored if detected along with the new object grasped by the sensor unit equipped operator 10. In one embodiment, the center or multiple antenna segments 38I, 38r, 38c are energized when both hands are engaged. Anatomically via the sensor units 4, it is determined "where" and "when" to energize the one or more respective antenna segments 381, 38r, 38c. Thereby, the potential for ambiguity during RFID polling and the total exposure of the operator 10 to radiation are reduced.

Advantageously, the antenna unit 6 and the one or two sensor units 4 provide a unique operational utility for handling objects 8 that requires a variety of different hand movements. The various sensors 24, 26, 36 reliably detect when the operator 10 engages an object 8 and avoid "false alarm" antenna initiation when the operator 10 touches, for example, a table or the body.

It may occur that the operator 10 engages an object 8 but the antenna unit 6 fails to acquire a signal in a given amount of time. In that case, the operator 10 is notified, e.g., by means of an audio signal, to shift the object 8, e.g., from one hand to the other, to remove any impedance.

Further, the operator 10 may note an RFID tag 2 is missing or a damaged. In that case, the operator 10 is instructed to affix an RFID tag patch and to start an initialization procedure. One embodiment of an initialization procedure is described below.

Operator Localization

Fig. 5 illustrates an exemplary application of the system shown in Fig. 1 augmented with technology for determining the position of the operator 10 with respect to containers, trucks or ULDs 18 to be loaded by the operator 10. Such a technology may be based on a global positioning system (GPS) or triangulation, which are known technologies. For example, U.S. 2006/0009240 describes a system for locating roaming objects that are provided with wireless tags. Accordingly, the operator 10 is in one embodiment equipped with a GPS device, and in another embodiment with a triangulation processor in communication with three transmitters 40 positioned at the periphery of a handling zone 42, as shown in Fig. 5. Several containers 18 park within the handling zone 42 and await loading or unloading. The position and destination of each container 18 are known using standard operations asset management and facility management programs that account for all catchments and either communicate to operators what to place where, or poll operators to indicate where allocated catchment assets are positioned.

The determination of the operator's position is coordinated with the sensor unit 4 worn by the operator 10. In use, the system tracks the operator 10 as long as the sensor unit 4 indicates that the operator 10 engages an object 8. When the sensor unit 4 indicates a release, tracking stops and the operator's final position at the time of release is determined. The final position is compared with the stored positions of the containers 18, and the container 18 closest to the final position of the operator 10 is identified as the container the operator 10 deposited the object 8 into. The system determines by a comparison of the known destination of the identified container and the object's destination whether the object 8 has been placed in the correct container. In case a match exists, reconciliation is completed. Reconciliation is described below in more detail. However, in case a mismatch exists, i.e., the operator 10 loaded the object 8 into the wrong container 18, an alarm is generated. As a mishandling is detected as soon as it occurs, the alarm allows the operator 10 to immediately remove the object 8 from the erroneous container 18.

In one embodiment, the antenna unit 6, under control of the sensor unit 4, can poll for an RFID response signal or a beacon from the container 18 while the object 8 is being grasped and the RFID tag 2 is being detected. The placement of the object 8 is then determined by the RFID response signal or beacon detected when the sensor unit 4 stops transmitting indicating succession of the grasp. Such RFID or beacon based localization for drop-off of the RFID tagged object 8, however, might give indeterminate results if the containers 18 are in close proximity so that the operator 10 cannot approach for drop-off without detecting multiple RFID response signals or beacons. For that reason, the above alternative embodiments may be preferred.

RFID Tag Initialization

Handling and transporting objects, in particular luggage or other objects to be transported by aircraft, increasingly requires stage-by-stage tracking and confirmation of individual luggage items such as during bulk loading of baggage into an aircraft hold or re-loading of transfer baggage, for example, for security reasons. In addition, it may be necessary to locate and remove specific objects in containers, ULDs or trolleys, because of a missing passenger or for the purpose of aircraft load balancing. For these applications as well as other applications in the area of mail handling, transportation and intra logistics of merchandise management and distribution it is desirable that each object 8 carries an operational RFID tag. Further, as mentioned above, the antenna unit 6 may fail to acquire a response signal, for example, because the original RFID tag 2 is missing, damaged, or no longer operable. Such an RFID tag 2 needs to be replaced.

In one embodiment, the system shown in Fig. 1 is used for initializing objects that do not carry an RFID tag, but need to be processed at a site that uses RFID technology for various purposes. For example, luggage items without RFID tags may arrive at a destination airport that uses RFID tags for applications such as baggage reconciliation or other tracking, logging and authentication purposes. The system is further used to provide a simple and effective way to reintroduce an RFID tag onto an object 8 whose original RFID tag 2 has been lost or damaged. The system provides for RFID tag initialization and coupling with the related record of the database 12 that can be performed by an operator 10 without direct, at hand recourse to RFID "write" facilities such as used in the baggage tag dispenser at the check-in counter to print the baggage tag and initialize such an RFID tag 2.

The process of initializing an RFID tag is depicted in Figure 6. In the illustrated embodiment, the operator 10 is further equipped with a processor 50 coupled to the antenna unit 6. In another embodiment, the processor 50 may be part of the processor and transceiver unit 14 shown in Fig. 1. The processor 50 is configured to access the database 12, which may be remotely located as shown in Fig. 1 , or worn by the operator 10. The operator 10 has a set of similarly, but uniquely labeled/pre- initialized auxiliary RFID tags 52. Each RFID tag 52 stores an identification number maintained in the database 12, but which has no corresponding baggage or passenger information attached in the database 12. The RFID tags 52 are available to the operator 10 and are stored in a dispenser or case 54 that is shielded against electromagnetic radiation. To facilitate attachment to the object 8 or an existent baggage tag that does not have an RFID tag or whose RFID tag is damaged, the RFID tags 52 can be sticky backed, or be part of and attachable as a secondary supplementary baggage tag.

The processor 50 is configured to access the database 12 and to relate a given RFID tag 52 to a data record identified by its human readable identification information 58 (hereinafter referred to as HRID 58), for example, an ID number, that is in one embodiment printed on a paper tag 56 attached to the object 8. Additionally, the system comprises one or more peripheral devices for entering the HRID 58 via voice (e.g., via headset 22), barcode or keyboard, whereas the processor 50 provides for associated recognition facilities. The operator 10 begins the initialization process by first detecting that after engagement of the sensor unit 4 and detection with the antenna unit 6 (or segments 38I, 38c, 28r) no response is forthcoming either due to damage or absence of an RFID signal 2. The operator then introduces the RFID tag 52 either by attaching a "sticky" RFID tag directly to the currently attached paper tag 56, or as a separate luggage tag with an embedded RFID tag. According to one embodiment, there is no need for equipment to "write" to the RFID tag 52, i.e., to store desired information on the RFID tag 52. In another embodiment, the antenna unit 6 may be used to write to the RFID tag 52.

The identification number of the RFID tag 52 is identical in format to those used for the luggage-tag embedded RFID tag. At any point in the process the operator 10 invokes the antenna unit 6 via the sensor unit 4, the system searches for a signal from one of the set of RFID tags 52 until it identifies an RFID tag 52 from the set of RFID tags 52 known to the processor 50 that has not been previously used/identified. The RFID tag 52 now attached to the luggage piece 8 identifies itself to the antenna unit 6 via its identification number at any point in the initialization process while the object 8 is grasped by the sensor unit 4. Once such an RFID tag 52 has been identified, the antenna unit 6 ceases to poll further and the operator 10 enters, e.g., voice (via headset 22), barcode or keyboard, sufficient information from the human readable luggage tag to identify the object 8. To complete initialization of the RFID tag 52, now determined by the processor

50 as being in the process of initialization, the identification number of the RFID tag 52 is associated with the HRID 58 on the object 8. In one embodiment, the operator 10 completes the initialization by entering, for example, via voice, the HRID 58 on the current paper tag 56, or the damaged RFID tag 2. To enhance operational processing when dealing with operational scenarios like transfer luggage, where an a priori list 60 can be created enumerating the specific paper tags 56 of the objects a specific flight can encounter, the operator 10 can be signaled to cease entry of the HRID 58 once a unique string match has been made against the candidates in the list 60 short of full entry of the HRID 58. An alternative mode of entering the object's HRID 58 is via a keyboard, barcode reader or optical scanner for optical character recognition.

Since those luggage pieces that are transfer baggage are known a priori, as well as their respective HRIDs, a finite set of HRID candidates exist that makes possible unique identification of an HRID 58 with just a partial string. Normally, the right-most part of the HRID 58 contains the most uniqueness and hence the operator can enter via voice the HRID 58 right to left. Alternatively the operator 10 can enter the HRID 58 using a keyboard/keypad or by direct use of a barcode reader. Once the HRID 58 has been acquired, the initialization is complete and all data associated with the "dumb" luggage tag is now associated with it. Accordingly the luggage piece can be handled seamlessly with all other RFID tagged luggage pieces for reconciliation and other tracking, logging and/or authentication applications.

If the mode of operation requires the RFID tag 52 to carry specific additional information like weight of the baggage or the HRID, the antenna unit 6 is set to a write mode, and writes to the RFID tag 52 via the antenna unit 6 (381, 38c, 38r) when the operator 10 grasps the baggage using the sensor unit 4. Similarly, some applications may require writing to the RFID tag 52 in coordination with the phase of reading from the RFID tag 52. In such an application, the antenna unit 6, under the control of the sensor unit 4, can seamless read/write information to an RFID tag while the operator 10 grabs the object 8.

Object Reconciliation

In one embodiment, the system is used for consigning passenger baggage to an aircraft to completely reconcile all loaded items with the passenger list and then confirm the baggage items have been put in the correct ULD 18. This means ascertaining the identity of each luggage item checked at the departure counter (check-in counter) or being transferred from another flight and associating it with a record in a database that confirms the passengers status (checked-in or boarded), and that the destination is consistent with the ULD 18 into which it has been manually loaded. Additionally, it needs to be considered that other ancillary information related to security, track and trace, weight balancing etc. may be accessed and used during the reconciliation process.

For airline baggage reconciliation, whether from a baggage handling sortation outlet where a ULD 18 is being loaded, an aircraft side where bulk luggage may be cross-checked again before loading/unloading, or for transfer luggage where either of the above baggage reconciliations settings may occur, tracking, logging and/or authentication is a non-trivial application when RFID tags 2 are used. The individual baggage items will normally be an unpredictable distance from and orientation toward the antenna unit 6. Additionally, metal partitions or metal side walls of a ULD 18 interfere with transmissions between the antenna unit 6 and the RFID tag 2. Closely packed luggage items themselves can cause multiple, simultaneous responses from RFID tags 2 resulting in colliding signals. Further, responses from RFID tags 2 will be cancelled when RFID tags 2 lay upon one another or RFID tags 2 touch a metal surface.

In one embodiment of a reconciliation procedure, the sensor unit 4 senses that an object 8 (luggage piece) has been grasped and activates the antenna unit 6 after a predetermined time. This initiates the polling of the RFID tag 2 only after it can safely be assumed the object 8 has been displaced sufficiently away from the other baggage on the chute/conveyor (or trolley) with similar RFID luggage tags so as not to initiate multiple RFID tag responses resulting in signal collision ambiguity. Alternatively, the antenna unit 6 may be always active ("always ON"), as mentioned above.

The antenna unit 6 receives from the RFID tag 2 a response signal containing an ID number. Based on the ID number the processor retrieves the appropriate data record to begin the passenger status validation and destination determination cardinal to baggage reconciliation. The processor in this instance can be remote (processor and transceiver unit 14) or worn by the operator 10 (processor 50), as mentioned above. The processor may contain all required information or communicate with a main processor or processors to access required databases to determine if the baggage in hand relates to the operations being performed. For example, if the operator 10 is loading luggage items into the cargo hold of an aircraft, the operator 10 is instructed to load only luggage items of boarded passengers. If the status of a passenger is "boarded", the operator 10 may receive a confirmation, for example, via an audio feedback via the headset 22. If a luggage item cannot be matched with a boarded passenger, the operator 10 may receive a warning via the headset 22.

ULD Interaction

Referring to Fig. 1 , where the operator 10 is expected to transfer the baggage physically to a specific ULD 18, the antenna unit 6 remains active as long as the baggage is grasped by the sensor unit 4. Thus, in one embodiment, the antenna unit 6 picks up a signal from the communication unit 20 of the ULD 18 as the operator 10 approaches the ULD 18 to deposit/transfer the respective luggage piece. According to this application, the system's processing functionality (processor 50 or processor and transceiver unit 14) verifies whether the ULD 18 is the correct destination for the baggage piece in process.

The communication unit 20 is in one embodiment an RFID tag attached to the ULD 18, e.g., in proximity of the loading side. Alternatively, the communication unit 20 is a beacon that transmits at a frequency distinct from the RFID tag 2 used on the luggage. Characteristic of such a ULD beacon is, for example, the beacon transmitting in the HF range and the RFID tag 2 emitting in the UHF range. Accordingly, depending on the embodiment of the communication unit 20, the antenna unit 6 either switches frequency to that of the ULD beacon, or uses the frequency of the RFID tag 2. The antenna unit 6 may have different antennas for polling an RFID tag 2 and the beacon. A beacon offers greater distance, no interference from luggage RFID tags 2 in the vicinity or already in the ULD 18, and a broader reception front that covers a greater angle of approach to the ULD 18. The ULD 18 carries an ID number specified by IATA (IATA standard "license plate") and is unique for each single ULD. The ULD 18 can permanently use this ID number in a signal emitted by its RFID tag or beacon to identify itself, and, through a database lookup, the destination and flight it is assigned. Alternatively, a fight number and destination can directly be loaded into the ULD RFID tag or beacon to be changed for every flight usage. If both ULD ID number and destination information are recorded and transmitted from the ULD's RFID tag or beacon, a redundancy double check can be performed before loading starts. In any event a ULD 18 can be unambiguously identified once its transmission has been received by the operator's antenna unit 6. The processor 50 of the antenna unit 6 or the processor and transceiver unit 14 may contain all required ULD ID numbers or communicate with a main processor or processors to access required databases to determine that the chosen ULD 18 is the right one. In one embodiment, the identity of the object 8 is determined when the operator 10 equipped with the sensor unit 4 grasps the object 8, as described above. The object's identity includes a baggage tag number that is used to access a database record to determine the destination of the object 8. In one embodiment, the object's destination is part of the identity stored on the object's RFID tag 2. The destination of the ULD 18 and the destination of the object 8 are compared to determine if the object 8 is transferred to the correct ULD 18. If the destinations match either an audio or audio-visual confirmation signal is generated, or no signal at all. However, if the destinations do not match an audio or audio-visual alarm is generated.

During this handling process, the antenna unit 6 receives a response signal from the RFID tag 2 of the object 8 being grasped, and a signal from the communication unit 20 of the ULD 18. The antenna unit 6 and the communication unit 20 are configured to allow the antenna unit 6 to distinguish between these signals. For example, the signals may have different frequencies, or may be the same, but differently coded. Accordingly, the antenna unit 6 either switches frequencies or is provided with different antennas for the various signals. Once the operator 10 grasps the object 8 and approaches the destination ULD 18, the signal from that ULD's communication unit 20 becomes the dominant signal. The antenna unit 6 waits for the sensor unit 4 to indicate the operator's grasp has been released.

Additionally a running total of the number of object 8 put into a given ULD 18 is kept and transmitted when the ULD 18 is full and sealed. The process works in reverse when a ULD 18 is unloaded. Confirmation or warning signals are conveyed by audio or visual feedback. The ULD 18 can also record the identity of the objects 8 being loaded and the loading sequence to facilitate finding a specific object 8 if it needs to be removed, for example, a passenger's luggage should the passenger fail to board the aircraft. The system above can be used to search for the suspect luggage and during the process of unloading the ULD 18 indicate when it has been grasped by the operator The above sequence of operations is analogous in embodiments where the ULD RFID or beacon are replaced with an active thangulation of the operator 10 while the sensor unit 4 is invoked.

Claims

1. A system for handling objects (8) provided with electronic identification (ID) devices (2), comprising: a sensor unit (4) having at least one first pressure sensor (24) and at least one stress sensor (26), wherein the at least one first pressure sensor (24) is configured to be positioned at an inner area of an operator's finger and to generate a first signal when pressure is applied to the at least one first pressure sensor (24), and wherein the at least one stress sensor (26) is configured to be positioned at an outer area of the operator's hand and to generate a second signal when subjected to stress; and an antenna unit (6) configured to emit a polling signal and to receive a response signal from an electronic ID device (2) within reach of the polling signal, wherein the antenna unit (6) is further configured to couple to the sensor unit (4) to be triggered as a function of the first and second signals.

2. The system of Claim 1 , wherein the sensor unit (4) includes a second pressure sensor (36) configured to be positioned at the palm of the operator's hand and to generate a third signal when pressure is applied to the second pressure sensor (36).

3. The system of Claim 1 or 2, wherein the antenna unit (6) is configured to couple to the sensor unit (4) via one of a wire connection and a wireless connection.

4. The system of any preceding claim, further comprising a processor and transceiver unit (14) coupled to process the response signal in coordination with information stored in a database (12), wherein the information relates to the object (8).

5. The system of Claim 4, wherein the processor and transceiver unit (14) is coupled to the antenna unit (6) via one of a wire connection and a wireless connection.

6. The system of Claim 1 , wherein the antenna unit (6) comprises a processor (50).

7. The system of any preceding claim, wherein the antenna unit (6) is configured to be worn by the operator (10).

8. The system of any preceding claim 1 , wherein the antenna unit (6) includes at least one antenna segment (381, 38r, 38c) having a predetermined field of radiation.

9. A method of handling objects (8) provided with electronic identification (ID) devices (2), comprising: providing an operator (10) with at least one sensor unit (4) configured to couple to an antenna unit (6), wherein the at least one sensor unit (4) has at least one first pressure sensor (24) and at least one stress sensor (26), wherein the at least one first pressure sensor (24) is positioned at an inner area of an operator's finger to generate a first signal when pressure is applied, and wherein the at least one stress sensor (26) is positioned at an outer area of the operator's hand to generate a second signal when subjected to stress; determining if the at least one first pressure sensor (24) generates the first signal; determining if the at least one stress sensor (26) generates the second signal; and triggering the antenna unit (6) as a function of the first and second signals to start processing a received response signal originating from an electronic ID device (2), wherein processing includes obtaining information stored on the electronic ID device (2).

10. The method of Claim 9, wherein the antenna unit (6) emits continuously a polling signal to poll any electronic ID device (2) within reach of the polling signal.

11. The method of Claim 9, wherein the antenna unit (6) emits a polling signal only when the first and second signals are generated.

12. The method of any one of Claims 9 - 11 , wherein the antenna unit (6) is triggered when the first and second signals are generated and are indicative of the operator (10) grasping the object (8) with one hand.

13. The method of any one of Claims 9 - 12, further comprising determining if the first signal exceeds a first threshold value, and determining if the second signal exceeds a second threshold value, wherein the antenna unit (6) is triggered when both threshold values are exceeded.

14. The method of any one of Claims 9 - 13, wherein the operator (10) is provided with two sensor units (4), one for each hand, wherein each sensor unit (4) further includes a second pressure sensor (36) secured to the support (30) and to positioned at a palm of the operator's hand to generate a third signal when pressure is applied, wherein the antenna unit (6) is triggered when two third signals are generated and are indicative of the operator (10) holding the object (8) with two hands.

15. The method of Claim 14, further comprising determining if each third signal exceeds a third threshold value, wherein the antenna unit (6) is triggered when the third signals exceed the third threshold value.

16. The method of any one of Claims 9 - 15, further comprising: using the obtained information to retrieve a record from a database, identifying at least one characteristic of an object (8) by means of the retrieved record, determining if the at least one characteristic is consistent with a predetermined characteristic, generating a confirmation signal if consistency exists, and generating an alarm signal if consistency does not exist.

17. The method of any one of Claims 9 - 15, further comprising: determining locations of a plurality of containers (18) within a handling zone (42), tracking the operator (10) to determine at least one location of the operator (10) while the antenna unit (6) is triggered due to the operator (10) grasping an object (8), terminating tracking the operator (10) when the object (8) is released, determining a final location of the operator (10), comparing the final location with the locations of the plurality of containers (18) to determine a container (18) closest to the operator's final location, and identifying the closest container (18) as the container (18) the operator (10) deposits the object (8).

18. The method of any one of Claims 9 - 15, further comprising: attaching an auxiliary electronic ID device (52) to an object (8) from which no response signal is received when grasped by the operator (10), obtaining an ID number stored on the auxiliary electronic ID device (52), entering human readable identification information (58) provided on the object (8), and associating the ID number of the auxiliary electronic ID device (52) with the human readable identification number (58) in a database as a data record relating to the object (8).

19. The method of Claim 18, wherein the human readable information (58) is entered via voice, scanning or keying.

20. A sensor unit (4) for a system for handling objects (8) provided with electronic identification (ID) devices (2), comprising: a support (30); at least one first pressure sensor (24) secured to the support (30) to be positioned at an inner area of an operator's finger, wherein the at least one first pressure sensor (24) is configured to generate a first signal when pressure is applied to the at least one first pressure sensor (24); and at least one stress sensor (26) secured to the support (30) to be positioned at an outer area of the operator's hand, wherein the at least one stress sensor (26) is configured to generate a second signal when subjected to stress.

21. The sensor unit of Claim 20, further comprising a second pressure sensor (36) secured to the support (30) to be positioned at a palm of the operator's hand, wherein the second pressure sensor (36) is configured to generate a third signal when pressure is applied to the second pressure sensor (26).

22. The sensor unit of any one of Claims 20 - 21 , wherein the pressure and stress sensors (24, 26, 36) include a piezoelectric material that converts a mechanical load to an electrical voltage.

23. The sensor unit of any one of Claims 20 - 22, wherein the support (30) has a glove-like configuration.

24. The sensor unit of any one of Claims 20 - 23, further comprising an interface unit (28) coupled to the at least one first pressure sensor (24) and to the at least one stress sensor (26), wherein the interface unit (28) is configured for communications with an antenna unit (6).