The invention relates to a data acquisition system for acquiring maintenance data.

Traditionally, maintenance, quality monitoring and inspection of building structures such as real estate assets or civil assets such as bridges and roads is performed by technically skilled inspectors on location.

Relevant maintenance aspects of building structures may be difficult to inspect or monitor as structural elements may be inaccessible or hard to test on site. For the purpose of managing maintenance activities computational models have been developed for estimating a physical state of building structures and sample elements may be destructively tested.

As an example, protective coatings on wooden components of outside walls are mainly monitored by visual inspection. Apart from destructive techniques, such as cutting a groove or drilbng a hole, ultrasonic equipment is available for periodically and manually measuring a local thickness of the coatings, however measuring results are inaccurate, unreliable and expensive to obtain. Similarly, in practice, it may be difficult or impossible to obtain moisture and/or thermal insulation data of roof structures in a cost effective way.

In summary, acquiring maintenance data of building structures is a labour intensive, inaccurate, non-reproducible and expensive process.

It is an object of the invention to provide a data acquisition system for acquiring maintenance data wherein at least one of the above disadvantages is counteracted. It is a further objection of the invention to provide a data acquisition system for acquiring maintenance data in an accurate though cost effective manner. Thereto, the invention provides a data acquisition system for acquiring maintenance data of building structures in an area, comprising a plurality of sensors located on the exterior of respective building structures, wherein the sensors are arranged for sensing maintenance data associated with the respective building structure and wherein the sensors are connectable to a publicly accessible data network provided in the area.

By providing a plurality of sensors on the exterior of building structures connectable to a pubhcly accessible data network maintenance data can be easily obtained and collected, e.g. for servicing purposes.

The invention is at least partially based on the insight that maintenance aspects of building structures mainly relate to attributes of the exterior of said building structures, including roof structures and outside walls, and that sensors can be located on said exterior for providing accurate measurement data.

The invention is also at least partially based on the insight that, presently, publicly accessible data networks such as LoRa networks, are available in a majority of areas where building structures are located. By connecting the sensors to a pubhcly accessible data network the maintenance data can be obtained in a cost effective manner.

By application of the data acquisition system, maintenance data may be remotely acquired via external sensing for storing, processing and forwarding the maintenance data, e.g. for servicing these building structures.

Further, the innovative application of sensors and data network reduces inspection time considerably while providing accurate and reproducible data that may be collected at desired time instants, e.g. periodically and/or real time.

As publicly accessible data networks are typically located outside building structures, the maintenance data can be collected without using any interior network of the building structures. Moreover, there is no need to enter the facilities of the building structure when installing the sensors simplifying and enhancing an installation management process, especially if a relatively large number of building structures are involved. Further, installation of the sensors on the exterior of the building structures may maintain desired characteristics of the building structures, such as isolation characteristics.

It is noted that within the context of the present application, the term exterior is to be understood as a part of the building structure that is not the interior of the building structure, said interior being surrounded by an outer shell including e.g. a roof structure and/or an outside wall.

Advantageously, sensors may include a transmitter for wireless transmission of the sensed maintenance data to the pubhcly accessible data network, thereby making any wired network connection to the network superfluous and improving flexibility in application of the sensors, both during construction and renovation projects of building structures. Alternatively, sensors may be connected using a wired connection, e.g. for further improving reliable operation of the system over an extended lifetime.

Preferably, a sensor includes a sensor element for measuring a physical maintenance parameter, such as temperature, a degree of moisture and/or a degree or intensity of UV radiation, and a local power supply unit for feeding the sensor element and/or the transmitter, thereby enabhng autonomous operation of the sensor. Then, the acquisition system does not interfere with any other feeding or data system inside the building structure having advantages in terms of privacy, reliability of operation etc.

The local power supply unit may be implemented as a battery or a solar cell. If the sensor element is arranged for converting incoming signals such as UV radiation into energy, the sensor element may also serve as a local power supply unit rendering the application of a separate local power supply unit such as a battery superfluous. The sensing element may include a photovoltaic cell for measuring UV radiation, e.g. for application of monitoring a coating layer on wooden structures. Further, the sensor may include a first sensing element for measuring temperature and a second sensing element for measuring electrical conductivity, rendering the sensor applicable for monitoring maintenance aspects of roof structures.

The sensors are preferably embedded in or covered by an outer layer of the shell, or located on a front side of the outer layer, the front side facing away from the interior of the building structure. As an example, a first sensor is located on a back side of a coating layer or thermal insulating layer of the building structure outside layer and a second sensor is located on a front side of the coating layer or thermal insulating layer serving as a reference sensor. Here, the back side of the outer layer faces towards the interior of the building structure, while the front side of the outer layer faces away from the interior of the building structure.

Generally, the outer layer of the building structure may include a multiple number of thermal insulating plates arranged next to each other, e.g. in the roof structure. Then, at least one of the thermal insulating plates may be provided with a sensor opening for receiving a roof sensor unit having an insulating plate portion placed in the sensor opening of the thermal insulating plate, the insulating plate portion having a geometry and dimensions matching a corresponding geometry and dimensions of the insulting plate opening so as to form, together with the thermal insulating plates, a substantially continuous insulating layer, and wherein the insulating plate portion is provided, on a back side thereof, with a first sensor, and, on a front side thereof, with a second sensor. Again, the back side of the insulating plate portion faces towards the interior of the building, while the front side of the insulating plate portion faces away from the interior of the building structure. The roof sensor unit is flexibly applicable in roof structures, as a separate unit, maintaining insulating performance of the roof structure while providing accurate and reliable maintenance data. The concept of applying a separate sensor unit placeable in a sensor opening of thermal insulating plate can not only be applied in roof structures but also in other outer layer portions of the building structure, e.g. in an outside wall.

In addition, the invention relates to an insulating plate portion.

Also, the invention relates to a method for servicing maintenance of building structures in an area.

The invention further relates to a computer program product. A computer program product may comprise a set of computer executable instructions stored on a data carrier, such as a flash memory, a CD or a DVD. The set of computer executable instructions, which allow a programmable computer to carry out the method as defined above, may also be available for downloading from a remote server, for example via the Internet, e.g. as an app.

Further advantageous embodiments according to the invention are described in the following claims.

It should be noted that the technical features described above or below may each on its own be embodied in a system and/or in a method, i.e. isolated from the context in which it is described, separate from other features, or in combination with only a number of the other features described in the context in which it is disclosed. Each of these features may further be combined with any other feature disclosed, in any combination.

The invention will be further elucidated on the basis of exemplary embodiments which are represented in the drawings. The exemplary embodiments are given by way of non-limitative illustration of the invention. In the drawings:

Fig. 1 shows a schematic view of a data acquisition system according to the invention; Fig. 2 shows a system view of the data acquisition system shown in

Fig. 1;

Fig. 3 shows a schematic cross sectional view of an UV sensor included in the data acquisition system shown in Fig. 1;

Fig. 4 shows a perspective view of a roof sensor unit included in the data acquisition system shown in Fig. 1;

Fig. 5 shows a schematic cross sectional view of the roof sensor unit shown in Fig. 4;

Fig. 6a shows another schematic cross sectional view of the UV sensor shown in Fig. 3;

Fig. 6b shows another schematic cross sectional view of the roof sensor unit shown in Fig. 4, and

Fig. 7 shows a flow diagram of a method according to the invention.

In the figures identical or corresponding parts are represented with the same reference numerals. The drawings are only schematic representations of embodiments of the invention, which are given by manner of non-limited examples.

Figure 1 shows a schematic view of a data acquisition system 1 according to the invention. The system 1 is arranged for acquiring maintenance data of building structures, including two houses 2 shown in Fig.l, in an area 3 such as a street, city, region, state etc.

The building structures 2 each have an interior 52 and an exterior 51. The interior 52 is surrounded by an outer shell 53 including an outside wall 14, a roof structure 15 and/or a front door. Generally, the shell 53 includes an outer layer.

The system 1 includes a plurality of sensors 4 located on the exterior 51 of respective building structures 2. Preferably, the sensors 4 are embedded in or covered by an outer layer of the shell 53, or located on a front side of the outer layer, said front side facing away from the interior 52 of the building structure 2. In the shown embodiment, two sensors 4 are provided per house 2, viz, a sensor on the outside wall 14 and a sensor on the roof structure 15. However, more than two sensors may be provided per building structure 2, e.g. three, four or ten sensors per building structure 2. On the other hand, a single sensor per building structure 2 may also be possible, e.g. on the roof structure 15.

The plurality of sensors 4 are arranged for sensing maintenance data such as temperature data associated with the building structure 2 where said sensors 4 are located. As an example, maintenance data may include data reflecting a state of the outside wall 14 or the roof structure 15 of the building structure 2. The sensors 4 are further connectable to a publicly accessible data network 8 provided in the area 3.

The publicly available data network 8 may be implemented as a wide area network WAN such as a long range wide area network LoRa that is typically used for data transmission have a low data rate, e.g. suitable for Internet of Things applications. Then, only a limited amount of energy may be sufficient to reahze data transmission having relatively low bandwidth as data packets may be relatively compact and time intervals between data transmission may be relatively large. The publicly available data network 8 may be located near other infrastructural elements, such as electrical lines, water pipes etc., typically along road structures, outside the building structures 2. The network 8 includes a number of gateways or receivers 9 receiving the maintenance data sensed by the sensors 4. Further, a server 10 is connected to the network 8 receiving the maintenance data received by the gateways 9, for storing and/or processing said data. The network 8 may be public or private, and may be accessible free of charge or may be commercial. The network 8 may be included in the data acquisition system 1.

The sensors 4 are arranged for autonomous operation or are stand alone. In the shown embodiment, the sensors 4 each include a transmitter 5 for wireless transmission of the sensed maintenance data, as a wireless signal W, to the publicly accessible data network located outside the building structures 2, a sensor element 6 for measuring a physical maintenance parameter, and a local power supply unit 7 for feeding the sensor element 6 and/or the transmitter 5. If the sensor element 6 is arranged for converting incoming signals into energy, the sensor element 6 may also serve as a local power supply unit rendering the application of a separate local power supply unit such as a battery superfluous.

The physical maintenance parameter that is measured by the sensor element 6 may be a temperature parameter, a degree of moisture parameter and/or a degree of UV radiation parameter. However, other physical maintenance parameters may be measured such as a location parameter, a nitrogen oxide parameter, an atmospheric pressure parameter, a motion parameter etc. Further, multiple physical maintenance parameters may be measured by a sensor element 6 or by a sensor 4. Physical maintenance parameters measured by sensor elements form maintenance data sensed by the sensors.

Figure 2 shows a system view of the data acquisition system 1 shown in Fig. 1. Here, a multiple number of sensors 4 transmit sensed maintenance data wirelessly to the gateways 9 of the LoRa network 8. The sensors 4 may optionally be provided with short range wireless connectivity elements such as BT devices for mutual data transfer such that data sensed by a multiple number of sensors 4 may be collected by a single sensor or other device for combined data transmission to the gateways 9 of the LoRa network 8, e.g. via a sensor that has a shortest distance to a gateway 9, e.g. within a prespecified time window. It is noted that, alternatively, the sensors 4 have a wired connection with the network 8 for wired transmission. The server 10, also referred to as application server, may be connected to the LoRa network 8 directly or via another network, e.g. a high speed data network such as a LTE based network or a 4G telecom network. The sensed maintenance data may be stored and/or processed by the appbcation server 10. Then, processed data may be forwarded to user devices, such as a client working station 11, a client mobile communication device 12 and/or a client server 13, e.g. for generating a maintenance overview of the building structures 2 or an automated maintenance service proposal for the building structures 2. Data may be processed at least partially by the application server 10 and or by the above-mentioned user devices 11, 12, 13.

Figure 3 shows a schematic cross sectional view of an UV sensor included in the data acquisition system shown in Fig. 1. The left hand side of Fig. 3 shows a single sensor embodiment, while the right hand side of Fig. 3 shows a dual sensor embodiment. In the single sensor embodiment, at the left hand side of Fig. 3, the sensor element 6 includes a photovoltaic cell 22 for measuring UV radiation IR incident thereon. The building structure outer shell includes a base layer such as a wooden layer 20 and an outside coating layer 21 covering the base layer 20. The photovoltaic cell 22 of the sensor 4 is located on a back side of a coating layer 21, i.e. sandwiched between the base layer 20 and the coating layer 21, the back side of the coating layer 21 facing towards the interior 52 of the building structure. Generally, the incident UV radiation IR propagates through the coating layer 21 thereby decaying before reaching the photovoltaic cell 22. After some time, the coating layer 21 may degrade, e.g. due to degradation and/or decomposition of macromolecules in a binding agent of the coating layer 21. As a result, the decaying effect of the coating layer 21 will reduce. By regularly measuring the intensity of UV radiation incident on the photovoltaic cell 22 a degradation rate of the coating layer 21 can be measured. In the dual sensor embodiment, at the right hand of Fig. 3, a similar photovoltaic cell 23 is located on the back side of the coating layer 21, while another, reference sensor 24 is located on the front side of the coating layer 21, for performing an UV radiation reference measurement, for comparison with the UV radiation measurement performed by the photovoltaic cell 23 at the back side of the coating layer 21. Here, the front side of the coating layer 21 faces away from the interior 52 of the building structure. Such a sensor construction may be applied in coated portions of the outer shell 53 of the building structures, e.g. a coated front panel. Upon comparing the UV measurements of both cells 23, 24 an UV transmission or UV transparence parameter may be determined indicative of a degradation rate of the coating layer 21. Optionally, the reference sensor 24 is not only arranged for performing an UV radiation reference measurement, but also for serving as a local power supply unit feeding the sensor element 6 and/or the transmitter 5. Further, optionally, the data acquisition system 1 includes a moisture sensor for sensing a moisture degree of the base layer 20 for acquiring further data indicative of a maintenance status of the coating layer 21. The moisture sensor can be implemented as a separate sensor element, e.g. as a moisture sensor in the base layer 20, or can be integrated with the photovoltaic cell 22, 23, e.g. sandwiched between the base layer 20 and the coating layer 21.

Generally, an outside wall or outside panel of a building structure can be provided. Here, the outer wall or outside wall may include an outer layer having a coating layer, at an exterior side of the building structure, the coating layer having a back side facing towards an interior of the building structure, and a front side facing away from the interior of the building structure, wherein a sensor such as an UV sensor is located on or near a back side of the coating layer, either embedded or covered by said coating layer. Optionally, a reference sensor such as a reference UV sensor is located on or near the front side of the coating layer. The outside wall or panel can be formed e.g. as an integral part of the outer shell or portion thereof or can be assembled to the building structure after being produced separately. Generally, sensors, especially the respective sensor elements thereof, may be embedded in or covered by an outer layer of the shell of the respective building structures, or may be located on a front side of the outer layer, the front side of the outer layer facing away from the interior of the building structure.

Figure 4 shows a perspective view of a roof sensor unit included in the data acquisition system shown in Fig. 1. Further, Fig. 5 shows a schematic cross sectional view of the roof sensor unit shown in Fig. 4.

The roof sensor unit 30 is formed as an insulating plate portion for insertion in a sensor opening 41 provided in a thermal insulating plate 40 of a roof structure 15 of a building structure 2. The insulating plate portion 30 has a geometry and dimensions, including a width W, a length L and a height H, matching a corresponding geometry and dimensions of the insulting plate opening 41 so as to form, together with the thermal insulating plate 40 and further thermal insulating plates 42, 43, 44 arranged next to each other, a substantially continuous insulating layer. In the shown embodiment, the insulating plate portion 30 has a box-shaped geometry that is filled with thermal insulating material such as polystyrene, expanded polystyrene EPS, polyisocyanurate PIR or polyurethaan PUR material forming a thermal insulating layer 36. The insulating plate portion 30 is provided, on a back side 34 thereof, with a first sensor 31, and, on a front side 35 thereof, with a second sensor 32. Here, the back side 34, also referred to as bottom side of the insulating plate portion faces towards the interior 52 of the building structure, then typically facing towards a mortar or concrete layer of the roof structure 15, while the front side 35, also referred to as top side of the insulating plate portion faces away from the interior 52 of the building structure, then typically facing towards a bitumen roofing covering such as a roofing felt layer of the roof structure 15.

Both the first and the second sensor 31, 32 include a first sensing element for measuring temperature and a second sensing element for measuring electrical conductivity being a measure of moisture, the measured parameters serving as maintenance data to be transmitted, via the data network 8, to the application server 10. Generally, by monitoring temperature values on the bottom side 34 and the top side 35 of the thermal insulating layer 36, a thermal insulation value can be derived, especially by determining a difference between a temperature at the top side 35 and a temperature at the bottom side of the thermal insulating layer 36. Further, by monitoring electrical conductivity or a degree of moisture, a maintenance state of a roof structure 15 at different levels of the insulating layer 36 may be evaluated. Also, any leakage can be identified.

In the shown embodiment, an optional third sensor 33 is applied in a central portion of the insulating layer 36, for measuring a degree of moisture inside the insulating layer 36 so as to provide information about a degree of moisture in the material of the insulating layer 36. In another embodiment, e.g. depending on a thickness of the insulating layer 36 and/or whether or not a stack of insulating layers are applied, on top of each other, a single sensor may be applied, or more than three sensors, e.g. four sensors or ten sensors. A further sensor may be applied for measuring a further physical parameter such as pressure or mechanical load. It is further noted that multiple roof sensor units 30 may be applied, at different locations, on a roof structure 15 of the building structure, e.g. if the roof structure has a relatively large surface area.

It is noted that the insulating plate portion 30 described above can not only be applied, as a roof sensor unit, in a roof structure 15, but also in other parts of the building structure shell such as an outside wall. In this respect it is noted that the insulating plate portion 30 can further not only be applied during construction of new building structures, but also in renovation projects or generally in existing building structures. Further, the roof sensor unit 30 may have a height H or thickness matching a thickness of the further thermal insulating plates 42, 43, 44 of the roof. In practice, individual roof sensor units may have mutual different thicknesses, such as a thickness A, B and C, so that a specific roof sensor unit may be selected having a thickness that optimally matches a thickness of the further thermal insulating plates 42, 43, 44 of the roof of a building structure.

Generally, the exterior 51 of the building structure is an outer shell 53 surrounding an interior 52 of the building structure, the outer shell 53 including an outside wall and/or a roof structure.

Figure 6a shows another schematic cross sectional view of the UV sensor shown in Fig. 3. Here, the outer shell 53 includes an outside wall.

The outer shell 53 has a base layer 20, such as a wooden layer, and an outer layer, such as a coating layer 21. The coating layer 21 has a front side 21a facing away from the interior 52 of the building structure, and a back side 21b facing towards the interior 52 of the building structure. A first sensor 23 implemented as a photovoltaic cell is located on the back side 21b of the coating layer 21. The first sensor 23 is covered by the coating layer 21. A second sensor 24, also referred to as reference sensor, is located on the front side 21a of the coating layer 21. Both the first and second sensor 23, 24 face outwardly, i.e. away from the interior 52 of the building structure.

Figure 6b shows another schematic cross sectional view of the roof sensor unit shown in Fig. 4. Here, the outside shell 53 includes a roof structure. The outside shell 53 has a base layer 56 such as a roof boarding, a top layer 55 such as roofing felt or roofing tiles, and an outer layer 54 such as a thermal insulating layer, located between the base layer 56 and the top layer 55. Again, the outer layer 54 has a front side 54a facing away from the interior 52 of the building structure, and a back side 54b facing towards the interior 52 of the building structure. Here, a first sensor 31 is covered by the outer layer 54, i.e. located on the back side 54b of the outer layer 54, and a second sensor 32 is located on the front side 54a of the outer layer 54. Further, a third sensor 33 is embedded in the outer layer 54. As shown in Fig. 6a and 6b, the outer layer 21, 54 may be formed as the outermost layer of the outer shell 53 or may be covered by another outermost structure e.g. including a roofing felt or roofing tiles.

According to an aspect of the invention, a method is provided for servicing maintenance of building structures in an area, comprising remotely acquiring maintenance data via external sensing.

Figure 7 shows a flow chart of a method 100 of servicing maintenance of building structures in an area according to the invention. Here, remotely acquiring maintenance data includes a step of sensing 110 maintenance data via a plurality of sensors located on the exterior of respective building structures, and a step of transmitting the sensed maintenance data from the plurality of sensors, via a publicly accessible data network provided in the area, towards a server for storing and/or processing said data.

The method of servicing maintenance of building structures can be facilitated using dedicated hardware structures, such as FPGA and/or ASIC components. Otherwise, the method can also at least partially be performed using a computer program product comprising instructions for causing a processor of a computer system or server to perform a step of transmitting maintenance data sensed via a plurality of sensors located on the exterior of respective building structures, via a publicly accessible data network provided in the area, towards a server for storing and/or processing said data. The step can in principle be performed on a single processor or server. However, it is noted that at least a sub-step can be performed on a separate processor, e.g. a sub-step of receiving, at a gateway of the data network, data transmitted from a sensor. A processor can be loaded with a specific software module. Dedicated software modules can be provided, e.g. from the Internet.

It will be clear to the skilled person that the invention is not limited to the exemplary embodiment represented here. Many variations are possible. As an example, it is noted that the building structures may include a commercial or industrial building such as a house or factory or another real estate or civil asset such as an infrastructural structure, e.g. road structures.

It is noted that a sensor including a photovoltaic cell for measuring UV radiation and a sensor including a first sensing element for measuring temperature and a second sensing element for measuring electrical conductivity, in particular when implemented in an insulating plate portion as described above, can not only be applied in combination with a data acquisition system as defined in claim 1, but more generally, in a data acquisition system for acquiring maintenance data of a building structure, wherein the sensors are arranged for forwarding sensed maintenance to a receiving device for storage and/or further processing.

Such variations shall be clear to the skilled person and are considered to fall within the scope of the invention as defined in the appended claims.