DE102011100046A1 - Radio frequency identification device for detecting objects marked with radio frequency identification device in transport path for objects, has radio frequency identification device transmission and reception unit - Google Patents

Abstract

The Radio frequency identification device (RFID)(50) has an RFID transmission and reception unit (19), while a transport path (2) is arranged a metal portion (4). The RFID transmission and reception unit applied on the side of a metal portion is arranged at the transport path. The metal portion is provided with a signal transmission portion for passing the RFID signals through the metal portion. The metal portion is formed by a metal plate (103) or a bottom plate (142), where the metal portion is part of a support structure, over which the transport path is lead.

Description

The invention relates to an RFID device, in particular for use in logistics.

Many retailers only accept deliveries of goods that are shipped with RFID transponders, such as B. RFID chips are marked. This allows you to completely automate the entire logistics chain. If the product label is barcode-coded, the product must be discontinued and the barcode must be read. RFID transponders can be read automatically.

For example, it is already known to use RFID transponders for monitoring the cold chain.

Nowadays, most deliveries of goods are still delivered via pallets. The RFID transponders are located on the pallet.

It is desirable transport routes, such. As loading points or loading docks, or routes for the distribution of goods within buildings or on a company premises, or transport containers such. As containers or the like to be provided with RFID antennas, so that the passage of an RFID transponder on this transport path or in or from the transport container is automatically detected. As a result, it is possible to detect via which transport path at which time which RFID chip was received or left, or one can monitor the contents of a transport container. This can be used, for example, to identify a delivery. You can also use this information for the automatic posting of incoming or outgoing goods as well as for transport monitoring.

A comprehensive presentation of RFID applications in logistics and the techniques used for this can be found eg. In Lenzbauer, S. - RFID Applications in Logistics, Diploma Thesis at the Vienna University of Economics and Business, Series of the Institute for Transport Economics and Logistics, No. 2, (2007 LOG), published in 2007 online via ePub, http: //epub.wu-wien .ac.at attached here as part of the disclosure.

In logistics such. As at loading points or other building accesses or in the area of transport containers or ships, where a goods transport takes place, the routes, passages or containers or transport vehicles are often subjected to harsh operating conditions. For example, transport vehicles such as trucks travel into contact with the building and with the building access device. When transporting goods or goods often transport vehicles or goods to limit. Containers are stacked very tightly, so that it is inevitable to touch each other. The means of transport and the transport routes and their limitations must therefore be designed for high loads; For example, fully loaded industrial trucks should be able to drive over the transit routes. Goods are also often transported on pallets, which are sometimes tons. These loads must withstand the means of transport and transport routes.

It is therefore desirable that such means of transport as well as transport route limitations are very robust. As a rule, therefore, metals such as sheet steel or steel plates are used for the production of such means of transport and transport routes.

On the other hand, transport means or transport routes should be as accurate as possible to detect goods or goods marked with RFID transponders. Therefore, in the field of such means of transport and transport routes consuming RFID transmitting or receiving devices are installed, which must be protected against the harsh operating conditions and in particular must be protected against shocks.

With regard to the detection of RFID transponders, the previous RFID transceiver arrangements are not optimal. In particular, there are problems in capturing metallic goods, transport containers with liquid materials which shield RFID signals, and goods transported in lattice boxes. The detection of such goods also causes problems when an RFID tag is attached to a pallet for transporting such goods.

It is therefore an object of the invention to provide an optimized for applications in logistics RFID device.

This object is achieved by an RFID device according to claim 1, Advantageous embodiments of the invention are the subject of the dependent claims.

The invention provides an RFID device for detecting objects marked with RFID on a transport path for the articles with an RFID transmitting and / or receiving unit and a metal region to be arranged on the transport path, wherein the RFID transmitting and / or receiving unit on a is arranged facing away from the transport path side of the metal region and wherein the metal region with a Signal passage region for passing RFID signals through the metal region is provided.

In an arrangement according to the invention, a metal region is provided between the RFID unit and the transport path. As a result, the RFID unit is particularly well protected.

Advantageously, a metal element which is anyway to be found in or on the transport path, such as, for example, a metallic base plate, a metallic boundary, a metallic wall or the like, is used as the metal region. For example, the RFID unit could be housed in a container wall provided with the signal passage area.

Particularly preferably, it is provided that the metal region is formed by a metal plate and / or a bottom plate. Preferably, an RFID detection is provided from below. As a result, palettes labeled with RFID can be detected particularly well, even if goods or packaging that are impenetrable to the RFID signals are transported thereon.

It is particularly preferably provided that the metal region is part of a supporting structure over which the transport path leads, wherein the RFID transmitting and / or receiving unit is arranged below the metal region. Preferably, an already existing metal construction is used as a receptacle for the RFID unit. This is particularly protected, there are no transport-disturbing structures necessary. In addition, the preferred detection can be achieved from below.

Particularly preferably, it is provided that the signal passage region has at least one slot in the metal region. A slot geometry is particularly preferred as a passband, since with such a slot geometry in particular a signal transmission with the lowest possible weakening of the metal region can be achieved.

Particularly preferably, it is provided that the signal passage region has a slot combination of a plurality of slots.

Particularly preferably, it is provided that the slot combination has an odd number of slots and preferably has three slots.

Particularly preferably, the signal passage region has a passage opening in the metal region whose largest inner width is smaller than half the wavelength of the RFID signals for which the RFID transmitting and / or receiving unit is designed.

It is therefore particularly preferred that the at least one slot has a slot length extending in the longitudinal direction which is smaller than half the wavelength of the RFID signals of the RFID transmitting and / or receiving unit. A slot having a sufficiently short slot length with respect to the wavelength behaves according to Huygens' principle as a secondary radiator, which can be excited by the RFID unit as a primary radiator for emitting the RFID signals. This makes it possible to achieve a good signal passage with little mechanical weakening of the metal region.

Particularly preferably, it is provided that the at least one slot has a slot length of about 100 mm to about 180 mm and preferably has a slot width of about 1 mm to about 20 mm.

Particularly preferably, it is provided that the at least one slot is filled with a dielectric material. Backfilling prevents dirt or other material from penetrating the signal passage area. This is permeable only to signals, but not to matter.

It is particularly preferred that an RFID antenna, in particular a patch antenna or a dipole antenna, is arranged at a predetermined distance from the metal region and in overlap with the signal passage region by means of a fastening device on the side of the metal region to be averted.

It is preferably provided that the dipole antenna is arranged substantially transversely to the at least one slot.

Particularly preferably, it is provided that the signal passage region is reinforced with a reinforcing element. Thus, a breakthrough of the metal region can be avoided even at high point load on the signal passage area.

It is particularly preferably provided that the reinforcing element has a metal plate element fastened to the metal region, in particular welded on the side to be averted, with a slot combination corresponding to the slot combination of the metal region.

It is particularly preferably provided that the metal region is designed as a floor or as part of a floor of the transport path and in particular as a travel path for vehicles, in particular industrial trucks.

Embodiments of the invention will be explained in more detail with reference to the accompanying drawings. It shows:

1 a side perspective view of a transport path in logistics using the example of a floor slab, which is run over by an industrial truck with an RFID-labeled pallet;

2 a perspective top view of the bottom plate of 1 ;

3 a detailed view of the bottom plate of 2 ;

4 an illustration of a slot combination in a bottom plate with three slots from below;

5 a perspective view of a Euro pallet with RFID identifier;

6 a schematic representation of a loaded pallet with RFID;

7 a schematic representation of a detection of a loaded pallet with a ground antenna;

8th to 12 different embodiments of slot arrangements in a schematic representation;

13 a schematic representation of a first embodiment of an antenna of an RFID transmitting and / or receiving device;

14 a schematic representation of a second embodiment of an antenna;

15 a schematic representation of a detection range of an arranged behind a metal region RFID antenna;

16 a schematic representation of a bottom plate from below with three antennas;

17 a schematic representation of an arrangement for finding a suitable position of the antenna;

18 a schematic representation of the receiving area of a arranged below a loading bridge antenna in the practical detection of pallets; and

19 a perspective view of the arrangement of the antenna and slot combination with a reinforcing element.

In 1 is schematically a building access 1 with a transport route 2 shown on the goods or goods in a building 3 can be introduced or can be applied. A lower limit 5 of the transport route 2 is through a metal area 4 educated. On the transport route 2 opposite side of the metal area 4 are several RFID receiving and / or transmitting units 19 appropriate. As a result, an optimized for the application in logistics RFID device 50 which, without any further protective measures, withstands the harsh working conditions in logistics and is nevertheless optimized with regard to RFID detection in logistics.

The RFID receiving and / or transmitting unit 19 is behind a metal area 4 arranged so that the metal area 4 between the transport route 2 and the RFID transmitting and / or receiving unit 19 is arranged and this protects accordingly.

In 1 is the RFID device 50 in the area of a transport route 2 the example of a loading station 100 with a loading bridge 102 and a goal 104 to complete the loading point 100 shown. The loading bridge 102 is made of metal and has a metal plate 103 that the metal area 4 forms, which the RFID transmitting and / or receiving unit 19 protects.

In 1 is shown that the loading bridge 102 to form the transport route 2 for an industrial truck 106 , here in the form of a forklift, is formed, which in particular for the transport of pallets 108 serves. The pallet 108 is an example of a charge carrier 110 , which is marked with RFID and in particular carries a transponder, as will be explained later.

The aim of RFID detection is by means of RFID pallets or boxes and generally load carriers 110 when passing a transport route boundary 5 capture. In particular, the driving over the transport route 2 through a charge carrier 110 be recorded. Accordingly, a forklift is with the pallet 108 on the loading bridge 102 in front of a loading gate 104 shown.

The metal plate 103 , which is an example of a lower transport route boundary 5 represents is with signal pass ranges 112 Mistake.

In particular, the metal plate 103 like this in 2 is shown with slots 114 provided by the under the metal plate 103 mounted antennas (in 2 not shown).

As this is closer in 3 is shown, the multiple slot arrangements 116 each with several slots 114 on the metal plate 103 in detail, the slots are 114 covered by plastic inserts to prevent in operation Dust, dirt or water through the metal plate 103 penetrates.

In 3 an oval marks three slots 114 through which exactly one antenna can radiate. Overall, in 3 three slot combinations or slot arrangements 116 to see.

4 shows the slots 114 from the bottom 120 the metal plate 103 seen from.

The slots 114 are by at least one reinforcing element 121 strengthened. In particular, a metallic reinforcing element provided with corresponding slots is provided 121 in the area of each slot arrangement 116 at the transport route 2 opposite side of the metal area 4 attached.

At the in 4 illustrated embodiment, the slots 114 through welded substrates in gates of metal plate reinforcements 121 reinforced, even at high point load on the metal plate 103 to prevent tearing.

Below the slots 114 is on a mounting arrangement 122 with distance to the slots 114 an antenna 124 the RFID transmitting and / or receiving unit 19 attached.

In the in 4 illustrated embodiment has the metal plate 103 on their bottom 120 several reinforcing ribs 126 in the form of T-profiles 128 on. On the undersides of these T-profiles is a sheet (eg aluminum sheet) for supporting the antenna 124 (For example, a patch antenna) is provided.

The T-profiles 128 form longitudinal beams 130 the loading bridge 102 , An aluminum sheet is left and right on side rails 130 the loading bridge 102 bolted to the mounting arrangement 122 to build.

4 thus shows a view of a slot arrangement 116 with three slots 114 from underneath. On the mounting arrangement 122 sits a UHF RFID antenna 124 pointing up at the slits 114 shine.

5 shows the pallet 108 in the form of a wooden pallet in euro format. On a pallet side member 132 is a transponder 140 unscrewed, an identification of the pallet 108 enabled by RFID.

Accordingly, shows 5 a wooden pallet in Euroformat with a screwed on transponder 140 ,

With the in the 1 and 2 illustrated use of the metal plate 103 as a base plate 142 and / or as a lower transport path boundary 5 can be an RFID acquisition of charge carriers 110 reach from below.

A schematic representation of such RFID detection from below is in 6 shown.

6 shows a metallic bottom plate 142 with signal passage area 19 and below mounted antenna 124 ,

In 6 is still a conventional conventional UHF antenna gate 144 represented by a left-hand carrier 146 , a right bearer 148 and a top cross member 150 consists. At the cross member 150 is an antenna 152 arranged on both sides 146 . 148 are each two antennas 152 arranged. The triangles shown schematically are those of the antennas 152 of the antenna gate 144 represent emitted electromagnetic waves. The UHF antenna gate 144 stands on or above the base plate 142 ,

Next is the palette 108 with the transponder 140 and with goods 154 presented on it.

In the example shown, the palette 108 with goods 154 loaded, which are formed of metal or which contain liquids; it is also conceivable that the goods 154 could be stored in a metal grid box (not shown) which is used very frequently.

Such a product 154 can not be penetrated by the UHF waves, so usually a detection of the transponder 140 neither through the antenna 152 on the upper cross member 150 of the antenna gate 144 , nor through the at the sides of the antenna gate 144 attached antennas 152 is possible.

Free access is only from below, ie through the slot combinations or slot arrangements 116 , in the bottom plate 142 possible.

In 6 is also good to see that the side antennas of the antenna gate 144 and the carriers 146 . 148 . 150 of the antenna gate 144 even the goods traffic of the industrial trucks 106 can obstruct while the ground antenna 124 passing through the slot combinations or slot arrangements 116 radiates, is completely submerged in the ground. Consequently, there is no damage to the ground antenna 124 possible.

In 7 is the practical capture of a palette 108 with a ground antenna 124 to see. It is the industrial truck 106 with the goods 154 , For example, beverage cans, loaded pallet 108 to see, with the transponder 140 the pallet 108 despite the loading of the metallic goods 154 slightly from the bottom through the bottom plate 142 through the ground antenna 124 is possible.

7 thus shows the detection of a loaded pallet 108 with RFID over a ground-antenna slot combination. The transponder 140 is in the palette 108 accommodated.

You can see clearly that the transport route 2 is completely free of antenna structures for the driver.

The following are various possible embodiments of slot arrangements 116 or slot combinations based on the representations in the 8th to 12 explained in more detail.

All illustrated slot combinations have one or more individual slots 114 on.

In empirical experiments it has been determined that at the RFID wavelengths used in Europe, slots with a width of 6 mm and a length of 140 mm are ideal. In general, slots are z. B. provided with a width b of about 1 mm to 20 mm and a length between about 10 mm and about 500 mm.

Has a slot arrangement 116 more than one slot 114 on, so preferably a predetermined distance d is provided. In particular, between the slots 114 a footbridge 160 provided with a distance d corresponding web width.

In empirical experiments, a web width of about 20 mm has proven to be ideal. Again, deviations are possible depending on the material of the metal region, in particular metal material and material thickness, and are selected according to the wavelength used.

Optimum dimensions of the slots 114 and the slot spacing d can be determined by a few empirical experiments.

8th shows a first possible slot arrangement 116 with a slot 114 , It becomes a slot combination of a single slot 114 educated. The slot width b is preferably about 6 mm, the slot length l preferably about 140 mm.

9 shows a second embodiment of a slot arrangement 116 with two slots 114 , The two slots 114 are aligned parallel to each other with a bridge between them 160 formed with the web width d. Preferably, the slot width b is about 6 mm and the slot length l is about 140 mm, and the slot spacing d is about 20 mm. Thus, a slot combination with two slots 114 educated.

10 shows a slot combination with three slots 114 ,

Preferably, the three slots 114 the in 10 slot arrangement shown 116 arranged parallel and aligned with each other, with two of the webs 160 , are each also formed with the length l of about 140 mm and the web width d of about 20 mm. The dimensions of the slots 114 are preferably again about 6 mm for the slot width b and about 140 mm for the slot length l.

11 shows a corresponding slot arrangement 116 with four slots 114 ; and 12 shows a corresponding slot arrangement 116 with five slots 114 , Web width d, slot width b, slot length l and alignment and in particular parallel arrangement of the slots 114 are similar to the other slot arrangements 116 intended.

The in the 8th to 12 illustrated slot combinations and slot arrangements 116 differ with respect to the width B and the height h of the detection area. Empirical experiments have shown that slot combinations with an odd number of slots appear to work better than those with an even number.

Therefore, a slot arrangement 116 with an odd number of slots 114 prefers.

Most preferred is a slot arrangement 116 with three slots. The combination of three slots 114 represents a good compromise between the demand for the lowest possible mechanical weakening of the bottom plate 142 and a minimum number of antennas 124 represents.

13 and 14 show two embodiments of as ground antennas 124 usable antennas. The antennas shown 124 are available on the market and in principle already known. 13 shows a patch antenna 162 , and 14 shows a dipole antenna 164 ,

The patch antenna 162 is, for example, a UHF patch antenna that radiates circularly polarized. The opening angle can be approx. 100 °, circularly polarized. The size can z. 170x170 mm, generally the size of the patch antenna 162 about λ / 2 × λ / 2, where λ is the wavelength of the RFID signals used. The power can be for example about 2.0 watts. A connection is z. B. via an SMA socket possible. Such antennas are in IP protection 65 available in the market.

In the 14 illustrated dipole antenna 164 in particular has a size of λ / 2, for example, the size is about 170 mm. Again, a power of 2.0 watts may be given. As a connection, for example, an N-socket is possible.

In particular, the dipole antenna 164 a λ / 2 dipole that radiates linearly polarized.

The detection range of an antenna 124 is described below with reference to the schematic representation in 15 explained in more detail. In 15 is the bottom plate 142 with the signal passing area 112 and the antenna 124 along with the coverage area 166 the antenna shown. The coverage area 126 has a height h and a width B.

Depending on the antenna used 124 can be the height h and the width B of the detection area 166 to adjust. When using antennas 124 that produce a very directional antenna field, such. B. the patch antennas 162 , is the reachable width B of the detection area 166 less than with dipole antennas 164 ,

Is the detection area 166 very broad, then can be with a few antennas 124 a loading bridge 102 completely cover. The height h of the detection area 166 determines the distance that a pallet 108 with transponder 140 during transport over the bottom plate 142 should have at most to be safe with the RFID antenna 124 to be recorded.

Empirical experiments have shown that complete field coverage of a metal plate 103 with a width of approx. 200 cm, approx. three slot combinations 116 each with three individual slots 114 where each slot combination 116 each with an antenna 124 equipped, suffice.

16 shows the arrangement of the three antennas 124 in a view on the metal plate 103 from underneath. It is a first antenna 124a , a second antenna 124b and a third antenna 124c shown. To each of the antennas 124a . 124b . 124c heard a slot arrangement 116 that is above the antenna 124 is arranged. 16 shows the view under the metal plate 103 with three antennas 124a . 124b . 124c ,

The following is an antenna tuning based on the illustration in 17 explained in more detail. 17 shows the slot arrangement 116 with reinforcing element 121 , Next is the mounting arrangement 122 in the presentation of 17 with an adjustable fastening device 168 provided so that the location of the antenna 124 is adjustable in at least two directions. The adjustable fastening device 168 has a displacement unit 170 on. The antenna here is a dipole antenna 164 used; the slot arrangement 116 has three individual slots 114 on.

Generally, the antenna becomes 124 under the respective slot arrangement 116 powered by a connection cable from an RFID control unit. Preferably, the antenna becomes 124 fed via a coaxial cable from a UHF reader as a control unit.

For optimum power transfer between antenna 124 and control unit, the output impedance of the RFID control unit should be based on the impedance of the cable and the impedance of the cable to the input impedance of the antenna 124 be matched.

In empirical experiments, it can be observed that the metal slot combination or slot arrangement 116 on the impedance of the antenna 124 can react. In other words, the antenna impedance may change compared to the impedance of a same antenna that is freely mounted. For this reason, it may be advantageous to perform impedance matching between the cable and the antenna with an adapter. Such adapters are common in UHF technology.

An alignment of all components is preferably carried out according to the method explained below:
Step 1: slidable mounting of the antenna 124 under the slot arrangement 116 ;
Step 2: Move the antenna vertically to the slot arrangement 116 (Changing the vertical distance to the slot combination) and moving the antenna horizontally to the slot arrangement 116 to the mounting point with the best detection range 166 to find;
step 3 By means of an impedance measuring device, check whether the adapter adjusts the impedance of the antenna to the impedance of the cable.

The following is based on the 18 the exploitation of the Huygens principle explained.

In 18 is the practical capture of the palette 108 with RFID when using a slot combination - for example, the slot arrangement 116 - to see. 18 shows the bottom plate 142 With the signal passage area 112 that has several slots 114 and the antenna 124 below the signal passage area 112 , In addition, the detection area 171 the antenna below the bottom plate 142 as well as the coverage area 166 the antenna above the bottom plate 142 shown. It is the capture of the pallet 108 with goods 154 by means of the transponder 140 shown.

The individual slots 114 The slot combinations are designed so that they can take over the function of a secondary radiator. That of the primary radiator, this is especially the antenna 124 below the slot combination 116 , emitted electromagnetic waves 172 meet the compared with the wavelength of the electromagnetic wave 172 enough narrow slits 114 on. Every slot 114 then behaves like a transmitter that can deliver its own waves. This is done according to Huygens's principle. Generally that is Huygens'sche principle, for example, in Gerthsen, Kneser, Vogel: "physics", Springer Verlag; Berlin, Heidelberg, New York; 13th edition, 1977 , shown in more detail.

If one wanted to forego this positive effect, the electromagnetic waves would be 172 to provide in another way. The bottom plate 142 would have to be opened by a very long slot, which should allow an unobstructed passage of the radiated directly from the ground antenna waves. That would be the bottom plate 142 mechanically very weakened and the antenna 124 would have to be correspondingly complex protected to prevent a collapse of the industrial trucks.

For the RFID frequencies used in Europe were slotted 114 in very thick metal plates 103 In the UHF range a length of 140 mm and a width of about 6 mm determined as optimal.

From the physics one knows according to the Huygens'sche principle: "If a plane wave hits a screen, in which an opening is, whose diameter is small compared to the wavelength, so spreads behind the screen around the opening as center a spherical wave out."

However, in explaining Huygens' principle, the opening is always made in infinitely thin materials; when used in floor slabs 142 from loading bridges 102 or the like lower transport path carriers are plate thicknesses of 8 mm or more possible. The welded for stability reasons reinforcing elements 121 are z. B. 10 mm thick, so that a total of a gap in a 18 mm thick material is used.

As a rule of thumb for the slot length l can therefore be used: l = a · λ / 2, where l is the slot length, a is a cutoff factor and λ is the wavelength of the RFID signals. Particularly suitable values for the reduction factor are: 0.5 <a <1.

The slot width b should be as small as possible.

The antenna 124 as a primary radiator below the slot combination 116 can be circularly polarized, z. B. as in the patch antenna 162 , or linearly polarized, e.g. B. as in the dipole antenna 164 , be. Regardless, the slots work 114 like polarization filter. This means that the slot combination 116 radiates as a secondary radiator regardless of the excitation with linear polarization.

Will a dipole antenna 164 used, it is preferably substantially transverse to the length of the slots 114 arranged.

The 19 shows a corresponding dipole in front of a slot arrangement 116 with the welded-on reinforcements (eg reinforcing element 121 ).

LIST OF REFERENCE NUMBERS

1

building access

2

transport

3

building

4

metal sector

5

limit

19

RFID transmitting and / or receiving unit

50

RFID device

100

Loading Station

102

leveler

103

metal plate

104

gate

106

Industrial truck

108

pallets

110

charge carrier

112

Signal passband

114

slot

116

slot arrangement

118

Plastic inserts

120

bottom

121

reinforcing element

121

Metal plate reinforcement

122

mounting assembly

124

antenna

124a

first antenna

124b

second antenna

124c

third antenna

126

reinforcing rib

128

T profile

130

longitudinal beams

132

Pallets stringers

140

transponder

142

baseplate

144

antenna gate

146

left carrier

148

right bearer

150

crossbeam

152

antenna

154

Were

160

web

162

patch antenna

164

dipole antenna

166

Detection area (on the front or top of the metal area)

168

adjustable fastening device

170

displacement unit

171

Detection area (on the back or underside of the metal area)

172

electromagnetic waves

d

slot pitch

H

Height of the detection area

B

Width of the detection area

l

slot length

b

slot width

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited non-patent literature

• Lenzbauer, S. - RFID Applications in Logistics, Diploma Thesis at the Vienna University of Economics and Business, Series of the Institute for Transport Economics and Logistics, No. 2, (2007 LOG), published in 2007 online via ePub, http: //epub.wu-wien .ac.at [0006]
• Huygens'sche principle, for example, in Gerthsen, Kneser, Vogel: "physics", Springer Verlag; Berlin, Heidelberg, New York; 13th edition, 1977 [0106]

Claims (14)

RFID device ( 50 ) for detecting RFID-marked objects ( 154 ) on a transport route ( 2 ) for the objects ( 154 ) with an RFID transmitting and / or receiving unit ( 19 ) and to be arranged on the transport path metal area ( 4 ), wherein the RFID transmitting and / or receiving unit on a side facing away from the transport path of the metal region ( 4 ) and wherein the metal region ( 4 ) having a signal passage region ( 112 ) for passing RFID signals through the metal area ( 4 ) is provided. RFID device ( 50 ) according to claim 1, characterized in that the metal region ( 4 ) through a metal plate ( 103 ) and / or a bottom plate ( 142 ) is formed. RFID device ( 50 ) according to claim 2, characterized in that the metal region ( 4 ) Part of a supporting structure ( 103 . 102 ) is, over which the transport route ( 2 ), wherein the RFID transmitting and / or receiving unit under the metal area ( 4 ) is arranged. RFID device ( 50 ) according to one of the preceding claims, characterized in that the signal passage region ( 112 ) at least one slot ( 114 ) in the metal region. RFID device ( 50 ) according to claim 4, characterized in that the signal passage region ( 112 ) a slot combination of a plurality of slots ( 114 ) having. RFID device ( 50 ) according to claim 5, characterized in that the slot combination ( 116 ) odd number of slots ( 114 ) and preferably three slots ( 114 ) having. RFID device ( 50 ) according to one of claims 4 to 6, characterized in that the at least one slot ( 114 ) has a length of the extending slot length (l), which is smaller than half the wavelength of the RFID signals of the RFID transmitting and / or receiving unit ( 19 ). RFID device ( 50 ) according to one of claims 4 to 7, characterized in that the at least one slot ( 114 ) has a slot length of about 100 mm to about 180 mm and preferably has a slot width of about 1 mm to about 20 mm. RFID device ( 50 ) according to one of claims 4 to 8, characterized in that the at least one slot ( 114 ) is filled with a dielectric material. RFID device ( 50 ) according to one of the preceding claims, characterized in that on the transport route ( 2 ) to be averted side of the metal region ( 4 ) an RFID antenna ( 124 ), in particular a patch antenna ( 162 ) or a dipole antenna ( 164 ), with a predetermined distance to the metal region ( 4 ) and in register with the signal passage region ( 112 ) by means of a fastening device ( 122 ) is arranged. RFID device ( 50 ) according to claim 10 and any one of claims 4 to 9, characterized in that the dipole antenna ( 164 ) substantially transversely to the at least one slot ( 114 ) is arranged. RFID device ( 50 ) according to one of the preceding claims, characterized in that the signal passage region ( 112 ) with a reinforcing element ( 121 ) is reinforced. RFID device ( 50 ) according to claim 12, characterized in that the reinforcing element ( 121 ) a metal plate element fastened to the metal region on the side facing away from the transport path, in particular welded on, with one of the slot combinations ( 116 ) of the metal region ( 4 ) has corresponding slot combination. RFID device ( 50 ) according to one of the preceding claims, characterized in that the metal region ( 4 ) as a floor or as part of a floor of the transport route ( 2 ) and in particular as a travel route ( 5 ) for vehicles ( 108 ), in particular industrial trucks, is formed.

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