DE102007030195A1 - Device for condition monitoring of components and structures - Google Patents

Abstract

A Device for condition monitoring of structures and components has a signal processing device (20) on or in the Structure or component (10) is arranged, monitors the state shall be. A signal output element (30) is connected to the signal processing device (20) connected. The signal delivery element (30) is for wireless Output of signals formed by the signal processing device (20). A reader (40) is for wireless readout of that from the signal delivery element (30) emitted signals over a transmission path (38) formed. The signal output element (30) is arranged in this way and configured such that a change of state of the to be monitored Building or component (10) to a change in state of Signaling element (30) and to change its Signaling properties leads from the reader (40) is detected.

Description

The The invention relates to a device for condition monitoring of components and structures.

components and structures or building parts are subject to a variety of stresses and strains. A timely detection damage allows prevention or even suitable measures for gentle repairs. At the very least, a timely detection of the risk of Damage to the environment of the building reduced. For this There has been a long-standing interest in surveillance the condition of components and structures.

Common So far, such monitoring by a repeated Visual inspection of the structures or components. A Visual inspection has the disadvantage, subjectively dependent on the persons to be, who make the visual inspection, and also a multitude of possible damages not at all to be revealed.

A Another possibility is usually very expensive Test equipment for the respective tests to create the location of the component or structure or components also have them examined in the laboratory. This has the disadvantage quite costly, because the transport of either test equipment or components is complex, must be organized and the corresponding consuming test equipment must also be procured.

A Another known possibility is the introduction of monitoring systems with a wiring. For this Cases is either the problem of a corresponding power supply to solve or there is no complete monitoring in the intervals between the inspections.

Just in view of the increasing trend towards building conservation the need here cheaper and easier Solutions for reliable condition monitoring of components and structures.

With containers is from the US-2007/0085677 A1 the idea known to attach a sensor and observation units to the container. By means of RFID technology, the data collected by the sensors are then transmitted further and enable intervention.

From the WO 2006/09485 A2 It is known to observe an environment by means of a sensor arrangement and to transmit via an RFID tag the events detected by the sensor.

In the WO 2006/108725 A1 It is proposed to detune or deactivate a high-frequency energy receiving resonant circuit within a so-called passive RFID-TAGS, wherein an antenna coil and a capacitor are provided with a porous dielectric. This porous dielectric is connected via a capillary with a liquid container. If a certain limit temperature is exceeded, the liquid in the liquid container expands due to the temperature-induced expansion in such a way that it soaks through the porous dielectric. As a result, the resonant circuit is detuned with the antenna coil and the capacitor and can not be read. In this way it can be permanently and reliably determined whether a certain limit temperature has been exceeded, for example in a cold chain or in an engine.

All These proposals from the prior art are for very special applications suitable, employ However, not with the problems in the building conservation interesting. So they are relatively expensive or consistently only suitable for a single application. Especially in the construction supervision, but also in a variety of other condition monitoring however, components become reliable, as well very cost effective and easy to monitor Devices needed.

task The invention is therefore, such a cheaper Propose device for condition monitoring.

These The object is achieved by a device for condition monitoring of components and structures, with a signal processing device attached to or is arranged in the component or structure whose condition is monitored should, with a signal output element, which to the signal processing device is connected, and which for the wireless delivery of signals is formed by the signal processing means for Be provided with a reader, which for the wireless read-out of the signal output element emitted signals over a transmission path is formed, wherein the signal output element arranged and is formed such that a change in state of the monitored Building or component to a state change of the signal delivery element and to a change in the signal output characteristics of the Signal delivery element leads from the reader is recognized.

With such a constellation, it becomes possible to monitor the conditions of components and structures not only inexpensively, but this also automatically, with relatively little time and yet reliably perform. This applies in particular to the monitoring of limit load conditions in the static and dynamic case.

One Particularly interesting field of application is monitoring of corrosion-endangered components, such as reinforcing steel in concrete. Here is the progress of carbonation within a component by providing corresponding inventive Concepts are monitored very practicable.

Especially it is preferred if the signal processing device has a or more RFID chips, the signal output element one or has multiple antennas, and the reader one or more Has RFID readers.

Especially it is preferred if the RFID antenna consists of wire.

Of the Use of RFID technology is in other areas of technology already proven and it is therefore cost effective and reliable a variety of components available, which can be used according to the invention. there According to the invention, so-called transponders consisting of RFID chips and antennas on, in or on the supervising Structure or component arranged.

Become several transponders or transponders with several antennas used, so can be changed in a very practical way and state changes spatially capture, for example, those already mentioned above Carbonation of reinforced concrete the direction of progressive Carbonation or depth, to which such a carbonation has penetrated into the building.

The especially applies when the antennas of the RFID devices themselves are exposed to corrosion and thus in case of corrosion the transmission of a signal is omitted. Because of the engagement multiple antennas can also have a location statement or a statement about the progress of corrosion are taken.

About that It also eliminates the problem of external power supplies and a frequently unwanted and unsightly Cabling outside on the structures is no longer necessary.

The wireless possibility of reading or reading has in addition to the purely visual and practical advantages also the Effect that a very typical vulnerability of the previous monitoring systems with a cabling is eliminated. In previous monitoring systems namely, the entry of a cable into the building automatically a weakening of the outer skin of the structure. This weak point can damage effects especially easy to come into the component or structure and yourself propagate along the cable into the building interior.

at the invention completely eliminates this risk.

By the inventively preferred use of RFID transponder Wireless monitoring is possible because have these chips polled wirelessly.

at require passive embodiments of such RFID chips these no longer own power supply. The power supply takes place when reading the RFID chips by the coupling of corresponding alternating fields from the outside. In semi-active transponders features the transponder via an additional energy source (Battery) to supply the RFID chip. Even in these cases becomes the energy for data transfer to the reader however, as in the passive case, out of the field of the reader won.

Next Structures made of reinforced concrete or structural parts in the form of girders It can also be components of machinery, of motor vehicles or act on other components.

According to the invention in particular two different modifications of conventional transponders can be used with advantage.

there is made use of that the signal delivery element of a Transponders on the one hand has an antenna, and on the other hand a connector that connects the antenna to the signal processor is connected, so preferably with the RFID chip.

A with the RFID chip connected antenna inside the component is thereby in the first of these two variants modified so that they are relevant or interesting changes of state of the component or structure can detect.

These thus modified antenna itself acts as a sensor of the RFID system. In this case, for example, the antenna with capacity or Inductors be provided, which are under the influence change the state change in a certain way as well, so that the resonance frequency of the antenna changes accordingly, especially shifting to a different value.

This change can then be read or read by the reader are detected.

at the second mentioned modification can be provided that the connection of the antenna to the RFID chip is changed by the state change, is interrupted in particular. Here, for example, a progressive Cracking or progressive carbonation due to corrosion lead to an interruption of this connection, so that the reader during the reading process of the antenna receives no or deactivated signals.

By the invention thus becomes an automatic, cost-effective, wireless monitoring of components and structures possible. At the same time, this represents a considerable security gain, because now, unlike the prior art, continuous monitoring the state of the components and structures is possible.

The usable sensor technology can be active and / or passive and is very diverse.

It creates a wireless interrogatable and intelligent signal processing device. The signal processing device is connected to a transmitting antenna, in turn, on or in a component to be tested, or Part of a building that monitors the state of this Component or part of the building is used. The antenna itself or an element connected to the antenna is changed by a change the state of the component changed. This change can as a signal of the signal processing device by the wireless Communication are transmitted. In case of interruption or Activation of the antenna by interrupting the connection The change is no longer or for the first time transmitted communication.

To Think is also the case that by the state change the connection between the signal processing device and the transmission output element only comes about by this connection, for example, conductive is done.

The corresponding antennas can be made of wire, for example consist. In a preferred embodiment is thereby provided that the condition monitoring device of components and structures with an antenna and / or the connection printed on the structure or component to be monitored is. In another preferred embodiment, however provided that the condition monitoring device of components and structures characterized in that the antenna and / or the connection on the structure to be monitored or component is glued.

A Elongation of the ferrite term of an antenna due to an elongation of the antenna Component may also detune a resonant frequency of the antenna, which is then passed on as information. A suitably equipped Reader can this information or this Read signal.

Possible it is also to change a dielectric constant. By changing the relative permittivity by the antenna becomes the antenna resonant circuit due to the parasitic Capacity detuned, so even in this case again results in a shift of the resonant frequency.

One Another interesting aspect of the invention is that a change of state can be observed, which is conventional was considered problematic because it transmits signals generally impaired.

is it is interesting, for example, the state change to monitor a metal foil near the antenna, for example, the presence or the abrasion or Decay of such a metal foil in the transmission path between the antenna and the reader, so now can the existence such a metal foil from the outset in the desired value of the monitored Signals are taken into account. The reader is So in this embodiment of the invention accordingly equipped so that it transmitted from the antenna Signals expected under consideration of this metal foil. Is then this metal foil corroded or by abrasion or in another form no longer or no longer in the original one Form exists, the transmission behavior changes accordingly the antenna seen over the transmission line to the reader, which is also monitored there can.

at important embodiments of the present invention is a key aspect, however, that a state change of the structure causes the antenna to break becomes or dissolves. Conversely, it is also possible that a previously provided short-circuit by a state change Will get removed.

The Communication of the RFID chip with an external one Evaluation device can be enabled or cut and this will be used as information.

By the use of multiple transponders allows the design in addition to a number of applications improve.

Conceivable is also the combination of multiple RFID chips. This will in particular also a combined monitoring of larger Areas or larger areas within a building or component possible.

Especially for continuous-time monitoring can also semi-active transponders are used. In certain embodiments also an additional integration of additional sensors possible. This can also be a monitoring of Environmental parameters such as the temperature take place, in addition for example, on the particularly relevant monitoring of progressive carbonation in a component or structure. The selection of passive or semiactive Systems will be based on the energy consumption and the desired Reading range hit.

With The invention provides a possibility in buildings or components, for example in beams of reinforced concrete structures, but also in other components to observe cracks and crack advances and monitor. Weakenings and other problems In this way, you can continuously observe be supplied. The security level at for example Structures are characterized by time-discrete or continuous Monitoring by means of particular semi-active transponder clearly increased, especially with the invention, a cost-effective Solution for such monitoring for Available.

When Keyword could be the invention as a concept for an "antenna as a sensor" Sensors can be connected, but this must be done not be the case and is currently at low cost and preferred embodiments also not made.

It becomes a wireless and non-contact measurement of carbonation progress possible in a reinforced concrete component. This perpendicular to Carbonation front arranged connections to the antennas or even the antennas themselves are corroded by corrosion the elimination of the passivation destroys, which is easy due to the change of the received signals respectively by detecting their absence in the reader and understand leaves.

The Invention can with a casting of transponders in the building material work yourself. The transponders from the RFID technology are doubly used, on the one hand for an identification and on the other hand for monitoring.

semi-active Systems can be used for continuous monitoring be used. A documentation of the life cycle of a component becomes so possible.

Technical Problems in the environment of construction sites can be this way be easily solved. The invention Devices can meet high mechanical requirements and signal-damping effects of building materials can by a corresponding calibration of the expected signals is compensated or be taken into account.

in the The following are some embodiments with reference to the figures the invention described in more detail. Show it:

1 a schematic view of a first embodiment of the invention;

2 a schematic view of a second embodiment of the invention;

3 a schematic view of a third embodiment of the invention;

4 a schematic view of a fourth embodiment of the invention; and

5 a schematic view of a fifth embodiment of the invention.

In the 1 is a component 10 shown schematically. It may be, for example, a beam or carrier.

Schematically, it is further indicated that the state of this component 10 through a crack 11 can be changed. This crack 11 likes to start monitoring the condition of the component 10 not yet exist and only occur in the course of this monitoring.

On the component 10 there is a signal processing device 20 , This signal processing device 20 has preferred and in the 1 an RFID (Radio Frequency Identification) chip.

Such an RFID chip of the signal processing device 20 can be a semi-active or even a passive transponder. The signals emitted by it contain in particular an indication for the identification of precisely this RFID chip of the signal processing device 20 , If a conventional and offered as a mass-produced device is used for this purpose, is the signal processing device 20 particularly inexpensive available.

On the component 10 according to the 1 There is also a signal delivery element 30 , The Signaling element 30 has a connection 32 and an antenna 31 on. The connection 32 transmits the signals of the signal processing device 20 to the antenna 31 ,

A reader 40 is provided that is either permanently arranged at the position shown schematically or is also positioned there for reading purposes. The reader 40 is an RFID reader. It's on the antenna 31 set signals transmitted.

The reader 40 can be outside of the component 10 located to receive the signals from the antenna wirelessly. The signals are from the antenna 31 over a transmission path 38 wireless to the reader 40 transfer.

But it is also conceivable, a variety of such readers 40 in an additional layer, for example in a facade of the building 10 each with respect to their associated transponders with the signal processing device 20 and the signal delivery element 30 to arrange for continuous monitoring.

It is easy to understand that the RFID antenna 40 without the crack in the component gives a different signal than after the occurrence of the crack, the connection 32 the antenna 31 interrupts at least one place. If this connection is interrupted, a signal transmission is inhibited and the reader 40 detects a corresponding error message at the signal input.

In the 2 a second embodiment of the invention will be explained in more detail. Here are several RFID chips 20 provided, which are each equipped with appropriate antennas.

It will be similar to the one in the 1 a component 10 assumed, which is not shown here for simplicity, on which an assumed crack 11 propagates. The propagation of the tear 11 Over time, there are more and more antennas 31 change their state or connections 32 through the crack 11 learn appropriate interruptions. The total information that is released changes in this way and gives information about which antennas are affected and where, therefore, the propagation of the crack 11 currently being propagated.

In the 3 another concept of the device according to the invention is explained. In this example, the signal delivery element becomes 30 thereby changing that a state change of the component 10 in the form of an elongation to a corresponding elongation or extension or shortening of a ferrite core 33 inside the antenna 31 the signal delivery element 30 leads. The change in the length of the ferrite core 33 leads to an effect in the right half of the 3 shown. There the frequency f is plotted to the right and the amplitude A, which occurs at a certain frequency, is plotted upwards. Two arrows indicate that the frequency at which the highest amplitude A occurs changes.

It can thus be seen that the resonance frequency of the antenna shifts. The inductance of the antenna and thus the resonance frequency thus changes due to the state change in the component 10 , In this way, this state change can in turn be done by the reader 40 be recognized.

In the 4 another arrangement is shown. Here is the component schematically 10 to recognize, on which a foil 25 glued on or already glued in the illustrated embodiment. This slide 25 carries in itself the RFID chip or the signal processing device 20 , This is also here about the connection 32 with an (RFID) antenna 31 connected.

It can affect the film 25 also act on a metal foil, which is in the transmission line 38 between antenna 31 and reader 40 located. In this case, the presence or the abrasion or deterioration of this metal foil 25 also be very well monitored by the device according to the invention.

In the 5 is similar in a representation to 1 underlined that antennas 31 not necessarily closed loops must form. Of course, there can be other types of antennas 31 be used, such as radio frequency antennas.

10

component

11

Crack

20

Signal processing device

25

foil

30

Signaling element

31

antenna

32

connection

33

ferrite

38

transmission path

40

reader

QUOTES INCLUDE IN THE DESCRIPTION

This list The documents listed by the applicant have been automated generated and is solely for better information recorded by the reader. The list is not part of the German Patent or utility model application. The DPMA takes over no liability for any errors or omissions.

Cited patent literature

• US 2007/0085677 A1 [0007]
• - WO 2006/09485 A2 [0008]
• WO 2006/108725 A1 [0009]

Claims (14)

Device for condition monitoring of components and structures, - with a signal processing device ( 20 ) on or in the component or structure ( 10 ) is arranged, whose state is to be monitored, - with a signal output element ( 30 ) which is connected to the signal processing device ( 20 ) and which is designed for the wireless delivery of signals which are received by the signal processing device ( 20 ), - with a reader ( 40 ), which is used for the wireless read-out of the signal output element ( 30 ) emitted signals over a transmission path ( 38 ) is formed, - wherein the signal output element ( 30 ) is arranged and designed so that a change in state of the monitored structure or component ( 10 ) to a state change of the signal delivery element ( 30 ) and a change in the signal output characteristics of the signal delivery element ( 30 ) generated by the reader ( 40 ) is recognized. Device for monitoring the condition of components and structures according to claim 1, characterized in that the signal processing device ( 20 ) has one or more RFID chips that the signal delivery element ( 30 ) has one or more antennas, and that the reading device ( 40 ) has one or more RFID readers. Device for monitoring the condition of components and structures according to claim 2, characterized in that the signal-emitting element ( 30 ) next to the antenna ( 31 ) a connection ( 32 ) of the antenna to the signal processing device ( 20 ) having. Device for condition monitoring of components and structures according to claim 3, characterized in that the state change of the monitored structure or component ( 10 ) a carbonation of the material of the structure or component ( 10 ) and that the carbonation leads to an interruption of the connection ( 32 ) or the antenna ( 31 ) leads. Device for condition monitoring of components and structures according to claim 3 or 4, characterized in that the antenna ( 31 ) and / or the connection ( 32 ) consists of wire. Device for condition monitoring of components and structures according to claim 3 or 4, characterized in that the antenna ( 31 ) and / or the connection ( 32 ) on the structure or component to be monitored ( 10 ) is printed. Device for condition monitoring of components and structures according to claim 3 or 4, characterized in that the antenna ( 31 ) and / or the connection ( 32 ) on the structure or component to be monitored ( 10 ) is glued. Device for condition monitoring of components and structures according to one of the preceding claims, characterized in that the signal processing device ( 20 ) is miniaturized. Device for condition monitoring of components and structures according to one of the preceding claims, characterized in that the signal processing device ( 20 ) additional sensors are connected. Device for condition monitoring of components and structures according to one of the preceding claims, characterized in that the state change of the structure or component to be monitored ( 10 ) the existence and / or the state of preservation of one in the transmission link ( 38 ) between the signal delivery element ( 30 ) and the reader ( 40 ), in particular a metallic foil. Device for condition monitoring of components and structures according to one of the preceding claims, characterized in that the signal processing device ( 20 ) and the signal delivery element ( 30 ) are passively formed. Device for condition monitoring of components and structures according to one of claims 1 to 10, characterized in that a power supply in or on the building or component ( 10 ) for the signal processing device ( 20 ) and / or the signal delivery element ( 30 ) is provided. Device for condition monitoring of components and structures according to claim 12, characterized in that the Power supply activated by the state change or disabled. Device for condition monitoring of components and structures according to claim 13, characterized in that the Energy supply by the state change takes place, in particular by electrochemical or temperature-related state changes.