ES2333933B1 - IDENTIFYING ELEMENT OF AN OBJECT, AND SYSTEM AND PROCEDURE FOR IDENTIFYING AN OBJECT. - Google Patents

Abstract

Identifying element of an object, and system and procedure to identify an object.

Identifying element of an object, to which it is partner, which includes means to implement a work cycle which comprises an activation state and a deactivation state, characterized by the fact that the identifying element it also includes means to detect the movement of the object at which is associated and means to generate a control signal concerning the movement of the object, so that, if the means of detection detect the movement of the object, the means of generation generate a control signal concerning the movement of the object that causes the identifying element to activate, while that, if the detection means detect that the object is stopped, the generation means generate a control signal indicative of that the object is stopped, which causes the element identifier is deactivated and remains in a dream state.

Description

Identifying element of an object, and system and procedure to identify an object.

The present invention relates to a system and a procedure to identify and monitor objects, and a identifying element associated with the object to be identified.

This invention is applicable in any activity, mainly from the industry in general and from the logistics in particular, where control is required remote a set of objects (such as pallets, boxes, containers, etc.) that move within an industrial environment known. To each of these objects an element is associated identifier of the invention. These identifying elements are communicate by radio frequency with a detection device (called reader) when passing through its coverage area, and that is why it is important to save energy when carrying out said radio frequency communication, thus extending the service life of identifying elements

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Background of the invention

There are numerous situations in environments industrial where an identification system is necessary and automated location of objects (products, boxes, pallets, containers, tools, workers, etc.), which are move and follow a known path within the industrial environment or between various industrial environments. In these situations you you need to record the trajectory of a certain mobile object to its passage through relevant points of its route, and send said information to a management system.

For this, there are radio frequency identification systems, called RFID (" Radio Frequency IDentification ") systems. An RFID system comprises at least one detection device, called a reader, and some identifying elements associated with each object to be identified and located. These identifying elements may be tags called RFID tags and they communicate wirelessly with the reader when they are located in their coverage area.

Each RFID tag can be associated with a Unique identifier. In this case, each object has an associated RFID tag that uniquely identifies it in a system of business information

There are two identification technologies by Basic radio frequency (RFID technologies): RFID technology passive, in which RFID tags do not include batteries and they get the necessary power to communicate with a reader to from the energy of the signal emitted by said reader; and the Active RFID technology, in which Active RFID tags are Powered by batteries.

The operational lifetime of an RFID tag Active ends when your battery's charge is depleted, so achieving savings in its consumption is an objective basic.

In Active RFID technology, an Active RFID tag (comprising at least one radio frequency device or " transceiver " coupled to an antenna for the emission and reception of signals, a control logic and a battery, which feeds all the hardware of the label) can implement and toggle a mode of operation of low consumption (it is said then that the label is asleep or deactivated), and a mode of high consumption (it is said then that the label is awake or activated), to save energy of said battery It should be noted that an Active RFID tag needs to be activated to interact and communicate with the reader.

As already stated, in an RFID system Active, energy expenditure is critical because it conditions time of operational life of a label.

Within this scope, in US2005 / 0134462A1 describes an Active RFID tag that incorporates a cell photovoltaic to recharge your battery, with the consequent increase in unit cost of the label and limitations of space and arrangement to properly place a solar panel on an object

A feature of an RFID tag when is within the coverage area of a reader is that you need to transmit a signal with at least your identifier, and that the reader receives said signal correctly, in order to be identified by it. At a given moment, a reader with a single receiver is capable of receiving only one signal or transmission of a label through the same channel of radiofrequency

If several RFID tags transmit at the same time or signal emissions overlap over time, said signals interfere and the reader may not receive correctly none of the signals and therefore not able to Identify any of the RFID tags. What is produced is produced known in the state of the art as a collision or interference mutual of the signals of two or more transmitters in a reader.

In the state of the art, there are descriptions of certain communication procedures between a reader and RFID tags for identification. As the reader does not know a priori how many RFID tags are in their coverage area, nor does a tag know how many more tags are in coverage, it is necessary that the identification procedure, or also called anti-collision procedure, arbitrate access to the transmission channel ( media access control) and communications between the reader and RFID tags, to minimize interference or collision of signals emitted by RFID tags.

In the prior art, two particular and suitable strategies are described as identification procedures for RFID systems: TTF ( Tag-Talk-First ) or RTF / ITF ( Reader / Interrogator-Talk-First ).

In the TTF strategy, a tag transmits its identifier (called " beacon ") at certain pre-configured intervals. A reader always has to be listening to the channel, waiting for identification tags of coverage tags. This strategy may be appropriate when there are not many objects together so that, in a reasonable time, a reader can receive all the identification signals of the existing tags. In this strategy it is usually required to deploy numerous readers within a limited environment, with the consequent cost of the system, in order to receive the identification signals of numerous labels. It should be noted that a label that uses the TTF strategy can spend long periods of time without being in the range of coverage of any reader. Therefore, if a tag is transmitting its beacon without being in the coverage area of a no reader, it will be wasting its energy.

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In the RTF / ITF strategy (" Reader / Interrogator-Talk-First ") the reader is always the first to transmit, sending an order that indicates to RFID tags that:

-

is it so in its coverage;

-

he moment in which they can begin to compete to identify themselves; Y

-

how much time they have to emit a signal with their identifiers

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In the RTF strategy, an RFID tag transmits only if it receives a specific and specific order from a reader. These RFID tags are transponders (devices that emit an identifiable signal in response to an interrogation signal, which they receive in the coverage area of said interrogation signal). Therefore, the interrogation order serves to synchronize the existing and activated RFID tags, and establish a communication for identification.

This strategy may be more appropriate when a very high number of tags can go through the range at once of coverage of a reader, and it is very important to guarantee the identification of all of them in a very short time.

In the state of the art, RFID tag systems are used that use the TTF or RTF strategy according to the requirements (technical and cost), characteristics or needs of the final application.

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An Active RFID tag never knows, except that be instructed, when it will be in the coverage range of a reader, so if:

-

uses the RTF strategy and stays active observing the channel in reception mode while waiting for an order from a reader, wastes its batteries and can run out of power in a few days; or

-

It uses the TTF strategy and transmits without being in the range of a reader's coverage, wastes its battery and decreases its operating life.

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Several are known in the state of the art options for saving battery power, which alternate low power modes (RFID tag deactivated, with its main functional blocks off) and high periods consumption (RFID tag awakens or activates, performing some operation or identification procedure).

Within this scope, in US 5 119 104 A it is proposed that a label that follows a TTF identification strategy only transmits its identifier if it is in motion and if it is stopped it remains off without transmitting its identifier. To distinguish whether it is stopped or moving, the tag incorporates a motion sensor.

In turn, in US 6 720 888 B2 it is proposed that there is a specialized reader with a transmitter device of a specific and particular signal and that an RFID tag incorporates an additional activation receiver circuit that activates it when it receives said specific signal from radio by said specialized reader. It is important that the additional activation circuit that incorporates a tag has a current consumption that also consumes the battery, and that the circuit increases the complexity and cost of both the RFID tag and the reader. In proposal ISOIIEC 18000-7 of Active RFID system (" RFID item management - Air Interface Part 7- Parameters for active RFID communications at 433 MHz ") the same idea is used to activate a label when passing through the coverage area of a reader and then start a process of identification of the RTF type.

A technical problem presented by Active RFID systems that use the RTF identification strategy is the over-interrogation of a label already identified by a specific reader. This phenomenon occurs when the tag enters the reader's coverage, is identified and remains in that reader's coverage. The reader can indicate to the label that it has been identified and that it can go to a sleeping state, but, after remaining in its coverage, after a while, it reacts again to the question marks and identifies itself unnecessarily and successively , with the consequent waste of energy.

In view of the state of the art, there is a need to maximize the operational lifetime of an Active RFID tag coupled to a mobile object typical of an industrial process ( pallet , box, container, etc.), which implements a procedure of RTF (" Reader-Talk-First ") type identification between the tag and a reader, without affecting or modifying said identification.

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Description of the invention

From what is described above, it is a object of the present invention to provide an element identifier that saves energy and therefore lengthens its useful life

This objective is achieved through claim 1, providing an identifying element of a object comprising means to detect the movement of the object to which it is associated and means to generate a control signal concerning the movement of the object, so that, if the means of detection detect the movement of the object, the means of generation generate a control signal concerning the movement of the object that causes the identifying element to activate, whereas, if the detection means detect that the object is stopped, the generation means generate a control signal indicative that the object is stopped, which causes the identifier element is deactivated and remains in a state of dream.

According to an embodiment of the invention, the Identifier element is an active RFID tag.

According to a second aspect of the invention, a system is provided to identify at least one object, which comprises an object identifier element, to which is associated, at least one detection device that identifies to the identifying element, and a communication channel between the identifying element and the detection device, in which the identifier element is an identifier element like the described above, and in which the detection device is adapted to communicate with the media to detect the object movement, through the communications channel.

According to one embodiment, the system is a system. RFID identification.

According to one embodiment, the system uses an identification procedure according to an RTF / ITF ( Reader / Interrogator-Talk-First ) strategy. In said identification strategy, the reader is always the first to transmit and initiate communications, and emits a master radio signal discontinuously that interrogates the identifying elements that pass through its coverage area to respond by issuing an identification signal .

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According to a third aspect, the invention it also provides a procedure to spread the identity of an object that has an object identifier element associated with it, which comprises the stages of:

to.

Verify the movement of the identifying element of the object;

b.

In case of negative result, deactivate the logic control of the identifying element for a period of deactivation preset, and continue with the procedure at end that time;

C.

Activate the identifying element for a while of preset activation, within which the following stages:

d.

Check if it is possible to establish a channel of communications between the identifying element and a device reader;

and.

In case of negative result and non-completion of the preset activation time, pass control of the procedure to step (d);

F.

In case of negative result and completion of the pre-set activation time, pass control of procedure to step (a);

g.

In case of positive result, send to device reader, from the identifying element, a control signal of object identification, through the channel of communications

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As follows from the procedure, since when an object is moving you can enter any moment in the coverage area of a reader, the device motion detector reports that there is movement to the logic of control of the label or identifying element, so that it activates or deactivate the tag or identifying element.

On the other hand, when the associated object is stopped, the motion detector device informs the logic control that there is no movement, so you can disable the label or identifying element leaving it in a very low mode I consume a certain time.

Finally, in case the object returns to move, the detector device activates the control logic of the tag or identifying element, to identify it from new.

Since, based on the activity of a standard industrial environment, it is assumed that for a while large enough, an object alternates periods of movement and predominant periods of null movement of long duration (for example in the hours of rest, or periods of inactivity of the industrial activity), and therefore the identifying element is a long time without the need to communicate with the reader, or at least not with a very short time cadence.

In addition, in periods of null movement, a object will not pass through the coverage area of other readers, located at strategic points of its route, so it is it is unnecessary for the identifying element to communicate with the readers so assiduously.

Therefore, through the procedure of present invention, the overall time at which a label or element identifier is inactive increases considerably, being able to adjust the activation and deactivation times according to requirements of the industrial application or the procedure of employee communications This achieves battery savings without modify the standard operation of a system labels

This characteristic is useful if, for example, the operational cycle that an object follows (for example, its transport and distribution between warehouses, etc.) is known, in which there are prolonged periods of movement known a priori , where an object is not going to go through the coverage area of a reader (for example, during truck transport of the object, which can last several days).

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In accordance with another aspect of the invention, provides a procedure to identify an object that has associated an object identifier element, by means of a reading device, which includes the steps of:

h.

Send an establishment request signal from communications to an identifying element;

i.

Check if it is possible to establish a channel of communications between the identifying element and the device reader;

j.

In case of positive result, receive a signal from object identification control, through the channel of communications;

k.

Identify the object, from said signal of control.

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The identification procedures described They are simple, robust and do not require any special hardware, reducing the cost of labels, in addition to not affecting the operation of a conventional reader.

Advantageously, the proposed procedures avoid over-communication of a label identified standing still within the coverage area of the reader, with the reader, since once identified it remains inactive until you resume movement or end a period of configurable downtime.

According to another aspect, the invention provides a computer program that includes instructions for program that run on a computer system to perform the procedure to spread the identity of an object that has associated an object identifier element.

Said computer program may be stored in physical storage media, such as ones recording media, a computer memory, or a memory of read only, or it can be carried by a carrier wave, such as electrical or optical

According to yet another aspect, the invention provides a computer program that includes instructions for program that run on a computer system to perform the procedure to identify an object that has an associated object identifier element.

Brief description of the drawings

For greater understanding of how much has been exposed Drawings are accompanied in which, schematically and only to non-limiting example title, a case study of realization.

In the drawings:

Figure 1 shows a representation schematic of a block diagram of an information system business, a reader and an RFID Active tag conforming to An embodiment of the invention.

Figure 2 schematically shows labels static, moving labels and labels that, when scrolling, They pass through the coverage area of a reader.

Figure 3 shows a block diagram of an embodiment of the procedure for identifying an object according to the invention.

Figure 4 shows a block diagram of an embodiment of the procedure to disseminate the identity and Identify an object according to the invention.

Description of preferred embodiments

In figure 1, it is schematically represented a reader 103 and an identifying element 107 according to an embodiment of the invention. The reader, located at a strategic point of passage of the objects, has the task of identifying a plurality of moving objects that pass through its coverage area.

Each object has an element attached identifier 107 which is, in the present embodiment, a tag Active RFID, which has a unique identifier associated.

When the reader 103 identifies an identifier tag or element 107, it is communicated to a management system 101 through a communication network 102, such as an Ethernet network. In other embodiments, this network may be, for example, the Internet.

The reader 103 has a controller 104 with sufficient memory processing and storage capacity, for example, of the type used in a personal computer or an embedded PC (" embedded PC "). The reader 103 further comprises a radio transmitting and receiving device (" RF transceiver ") 105 coupled to an antenna 106 to be able to radiate on a radio frequency channel and, thus, communicate through said channel with the tag or element RFID identifier 107 which includes, in turn, a radio transmission and reception device 109 that carries an antenna 110 coupled.

The label or identifying element 107 it comprises a control logic 108 of low cost and reduced computing capacity, implemented on, for example, a microcontroller It also incorporates a detection device movement 112 connected to control logic 108, to indicate if there is movement or the associated object is stopped. The device 112 can be a low cost motion sensor with a very low consumption, which may be, for example, of the order of consumption of the label or identifying element deactivated. In addition, the tag or identifying element 107 is fed with a battery 111 that can be replaceable or not.

In addition, the tag or identifying element 107 It can carry a memory of data and sensors (temperature, humidity, etc.) not shown in figure 1.

Figure 2 schematically shows a situation in which there are stopped or static RFID tags 210, and moving labels 204 and 206, within a path of a industrial or transit environment between different environments Industrial Labels 204 and 210 are not in the zone of 202 coverage of a Reader. In turn, there are 206 tags that during their displacement passes through coverage area 202 of a signal of a reader 200, and a tag 211 that has entered the zone of coverage 202 and remains without moving within the zone of reader coverage 200, establishing communication with the Same for an indefinite time.

The reader and system tags implement an identification procedure that follows a RTF strategy ("Reader-Talk-First") where the  Communications are always initiated and commanded by the reader. TO an embodiment of said is described below process.

Figure 3 shows a procedure for monitor objects according to an embodiment of the invention.

At the start of the procedure, in step 301 control logic 108 verifies whether the label or element identifier is stopped or moving, questioning the motion detector device 112.

In case of negative result, the label or identifier element happens to be disabled 302 for a while undefined, achieving the lowest possible battery cost by have the tag or identifying element several of its blocks Functional deactivated.

In an embodiment of the invention, the microcontroller that implements control logic 108 can be set to be in a very low power mode of which it can only exit through an interruption mechanism, that is, if you change the logical state of an input digital signal to which the motion detector device 112 is connected. In this case, if, in step 302, the motion detector device 112 detects that there is displacement of the label or element identifier, generates an event or signal that interrupts and activates the microcontroller, going to step 303.

On the other hand, in case of positive result in step 301, this means that the tag or element identifier is in motion, and procedure control Continue directly with step 303.

In said step 303, the RFID tag or identification element is activated for a Ton time, during which it observes the radio frequency channel that the reader uses to communicate with it. If it receives a signal from the reader, also called the reader's identification order, it means that it is in the reader's coverage area, and consequently the tag or identifying element establishes communication with the reader in step 305 so that the reader identifies it and monitors its position. and establishes a communication, in response to the reader's orders.

However, if during the Ton time the label or identifying element does not detect activity in the pre-established radio frequency channel, in step 304, it is deactivated and remains deactivated during a Toff time, with several (or all) functional blocks deactivated, achieving a very low battery consumption. When the Toff time expires, the tag or identifying element 107 is activated and returns to step 301 by restarting the procedure again, continuing the duty cycle.

Figure 4 shows a block diagram of a process according to another embodiment of the invention. Said procedure for disseminating the identity of an object that has an associated object identification element (in this case an RFID identification tag or element), to identify it by means of a detection device, such as a reader, comprising the steps of 401 verifying the movement of the tag or identifying element associated with the object; Subsequently, in case of negative result, step 402 of deactivating the label or identifying element is performed during a deactivation time Toff ', and, at the end of said time, step 403 is continued. In case of positive result, it is performed directly the step 403 of activating the tag or identifying element during an activation time Ton ', within which steps 404 are performed to verify whether it is possible to establish a communication channel between the RFID tag or identifying element and the reader; in case of negative result and non-completion of the pre-established activation time (condition 405), return to step 403. On the other hand, in case of negative result and end of the activation time Ton '(condition 406), returns to step 401 to verify the movement of the tag or identifying element. Finally, in the case of a positive result, step 407 is sent to send to the reader, from the label or identifying element, an object identification control signal, through the communications channel.

Consequently, said procedure for spreading the identity of an object is done entirely by the tag or RFID identifier element, and, on the other hand, the reader performs a procedure to identify an object according to a embodiment of the invention, comprising the steps of sending a communication establishment request signal to the label or identifying element; check if possible establish a communication channel between the tag or item identifier and reader; in case of positive result, receive an object identification control signal, through the communications channel; and identify the object, from said control signal

Although they have been described and represented specific embodiments of the present invention, it is clear that the person skilled in the art may introduce variants and modifications, or replace the details with others technically equivalent, without departing from the scope of protection defined by the attached claims.

Although also the realizations described of the invention with reference to the drawing comprise computer systems and processes performed in systems computing, the invention also extends to programs of computer, more particularly to computer programs in or on carrier means, adapted to put the invention into practice. The computer program can be in code form source, object code or intermediate code between code source and object code, such as in partially compiled form, or in any other form suitable for use in the implementation of the processes according to the invention. The carrier medium can be any entity or device capable of carrying the program.

For example, the carrier medium may comprise a storage medium, such as a ROM , for example a CD ROM or a semiconductor ROM , or a magnetic recording medium, for example a floppy disc or a hard disk. In addition, the carrier means may be a transmissible carrier medium such as an electrical or optical signal that can be transmitted via electrical or optical cable or by radio or other means.

When the computer program is contained in a signal that can be transmitted directly via a cable or other device or medium, the carrier medium may be constituted by said cable or other device or means.

Alternatively, the carrier means can be an integrated circuit in which the computer program is encapsulated ( embedded ), said integrated circuit being adapted to perform, or to be used in the realization of, the relevant processes.

Claims (11)

1. Identifying element of an object, to which it is associated, which comprises means for implementing a duty cycle comprising an activation state and a deactivation state, characterized by the fact that the identifying element also comprises means for detecting movement of the object to which it is associated and means for generating a control signal relating to the movement of the object, so that, if the detection means detect the movement of the object, the generation means generate a control signal relating to the movement of the object that causes the identifier element to be activated, while, if the detection means detect that the object is stopped, the generation means generates a control signal indicating that the object is stopped, which causes the identifier element to be deactivated and Stay in a state of sleep. 2. Element according to claim 1, characterized in that it is an active RFID tag. 3. System for identifying at least one object, comprising an object identifying element, to which it is associated, at least one reading device that identifies the identifying element, and a communication channel between the identifying element and the reading device, characterized by the fact that the identifying element is an identifying element according to any of claims 1 to 2, and by the fact that the reading device is adapted to communicate with the means to detect the movement of the object, through the communications channel . 4. System according to claim 3, characterized in that it is an RFID radio frequency identification system. 5. System according to any of claims 3 or 4, characterized in that it uses an identification procedure according to an RTF / ITF strategy ( Reader / Interrogator-Talk-First ).

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6. Procedure to disseminate the identity of an object that has an object identifier element associated with it, a reading device and a communication channel, and comprising the stages of:

to.

Verify the movement of the identifying element of the object;

b.

In case of negative result, deactivate the logic control of the identifying element for a period of deactivation preset, and continue with the procedure at end that time;

C.

Activate the identifying element for a while of preset activation, within which the following stages:

d.

Check if it is possible to establish a channel of communications between the identifying element and a device reader;

and.

In case of negative result and non-completion of the preset activation time, pass control of the procedure to step (d);

F.

In case of negative result and completion of the pre-set activation time, pass control of procedure to step (a);

g.

In case of positive result, send to device reader, from the identifying element, a control signal of object identification, through the channel of communications

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7. Procedure to identify an object that it has an associated element identifier of the object, through a reading device, which includes the steps of:

h.

Send an establishment request signal from communications to an identifying element;

i.

Check if it is possible to establish a channel of communications between the identifying element and the device reader;

j.

In case of positive result, receive a signal from object identification control, through the channel of communications;

k.

Identify the object, from said signal of control.

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8. Computer program characterized in that it executes the method to identify an object according to claim 6. 9. Computer-readable support characterized in that it incorporates the code that allows the execution of the method of claim 6. 10. Computer-readable carrier wave characterized in that it incorporates the code that allows the execution of the method of claim 6. 11. Computer program characterized in that it executes the method of claim 7.