WO2024208519A1

WO2024208519A1 - Sensor of a sensor network

Info

Publication number: WO2024208519A1
Application number: PCT/EP2024/055810
Authority: WO
Inventors: Patrick MOSER; Florian ALLGAIER
Original assignee: Vega Grieshaber Kg
Priority date: 2023-04-03
Filing date: 2024-03-06
Publication date: 2024-10-10
Also published as: DE102023108466A1

Abstract

A sensor of a sensor network, designed for process automation in an industrial or private environment, comprises a communication module and a processor, the processor being able to switch the communication mode of the communication module from a first communication mode to a second communication mode.

Description

sensor of a sensor network

reference to related applications

The present application claims priority from German patent application No. 10 2023 108 466.6, filed on April 3, 2023, which is incorporated in its entirety by reference into the present document.

field of the invention

The invention relates to sensor networks for process automation in industrial or private environments. In particular, the invention relates to a sensor of a sensor network, a sensor network with a plurality of such sensors, a use, a method for operating a sensor, a program element and a computer-readable medium.

Technical Background

Gateways can be used to forward sensor data. Gateways are used to receive and forward data, whereby the communication protocols for receiving and sending can be different. The data sources can be, for example, a local computer or sensors, and the data sink can be a remote computer, e.g. a server that is connected to the gateway via the Internet or mobile communications. The interfaces can be wired or wireless on both sides. The energy to operate a gateway is usually drawn from the power grid, so flexibility is limited despite possible wireless interfaces. Alternatively, a gateway can also be operated with a battery, but the usual power consumption of a gateway means that the battery has to be changed or recharged frequently, which reduces cost-effectiveness.

Summary

It is an object of the present disclosure to provide a sensor network that provides an energy efficient communication mode.

This object is achieved by the subject matter of the independent patent claims. Further developments of the invention emerge from the subclaims and the following description of embodiments.

A first aspect of the present disclosure relates to a field device or a sensor of a sensor network, set up for process automation in an industrial or private environment. The field device comprises, for example, a sensor, a display module, a gateway, and/or a removable module.

The field device or the sensor has a communication module that is set up to receive external sensor data from a neighboring sensor of the sensor network in a first communication mode. The communication module is also set up to send the received sensor data to a receiver outside the sensor network in a second communication mode. The sensor also has a processor that is set up to switch the communication module from the first communication mode to the second communication mode.

According to one embodiment, the field device or sensor has only a single communication module, which is typically a radio module. The selected communication mode can be switched. The Switching the communication mode no longer makes the use of a permanently installed gateway necessary, since one of the sensors in the sensor network can take on the role of the gateway.

Several communication modules can also be provided, e.g. in a three-stage structure:

1. Bluetooth is used, for example, to activate the second communication module.

2. Communication module protocol is DECT NR+: Normally it is disabled because it requires more power than Bluetooth. Bluetooth activates it, allowing data exchange (faster than Bluetooth).

3. NB-loT: Data is sent to the cloud.

It is possible that one, two or even three separate components/radio modules can be used for the three communication modes.

Which sensor takes on the role of the gateway is not determined deterministically; rather, this role can be performed alternately by different sensors over time. The sensors can communicate with each other and independently select which device takes on this role.

According to an embodiment of the present disclosure, the processor is configured to decide whether the own sensor data acquired by the sensor is sent by the communication module to the neighboring sensor in the first communication mode or to the receiver outside the sensor network in the second communication mode.

In the first case, another sensor or another field device in the sensor network takes on the role of the gateway. In the second case, this role is taken on by the sensor itself. According to a further embodiment of the present disclosure, the processor is configured to switch the communication module regularly or as needed from the first communication mode to the second communication mode. A third (or fourth, etc.) communication mode/module/protocol can also be provided. This is very economical and can be permanently active. It can be provided that the other communication modes are activated via a signal.

According to a further embodiment of the present disclosure, the processor is configured to switch the communication module from the first communication mode to the second communication mode based on a trigger event by the adjacent sensor. The processor can also be installed/present in the communication module.

According to a further embodiment, the sensor or field device is configured as a buffer for the external sensor data. The sensor can thus collect external sensor data from neighboring sensors and then forward it in bundles to the external receiver.

According to a further embodiment of the present disclosure, the sensor or the field device is configured to simultaneously send the external sensor data and the own sensor data to the receiver.

According to one embodiment, the measuring device is configured to communicate with the other measuring devices according to one or more of the network protocols (first communication mode) Bluetooth LE, MATTER, LoRa (Long Range Wide Area Network), Symphony Link, Weightless, Wi-Fi HaLow (WLAN standard 802.11 ah), Dect ULE (Digital Enhanced Cordless Telecommunications Ultra Low Energy), Dect NR+, M- Bus Wireless, Wireless HART, Ethernet, or Mioty. In addition to these In addition to protocols known to those skilled in the art, other protocols, such as proprietary or future protocols, may also be used.

According to one embodiment, the measuring device is configured to communicate in its role as a gateway with an external receiver that is not part of the network of measuring devices according to one or more of the communication standards (second communication mode) 1G, 2G, 3G or GSM, 4G or UMTS, 5G or loT, Sigfox, Waviot, RPMA, NB-IOT, LTE-M, LoRa, or CAT-M1. In addition to these protocols known to the person skilled in the art, other protocols, e.g. proprietary or future protocols, can also be used.

According to one embodiment of the present disclosure, the DECT-2020 (DECT NR+) standard is used in stand-alone NB-loT devices in the form of sensors.

According to another embodiment of the present disclosure, the processor is further configured to delete the foreign sensor data after sending.

According to another embodiment of the present disclosure, the sensor is a level sensor, for example a level radar sensor, a limit level sensor, a pressure sensor or a flow sensor.

Another aspect of the present disclosure relates to a sensor network comprising a plurality of the sensors described above and below.

Another aspect of the present disclosure relates to a gateway for a sensor network as described above.

A further aspect of the present disclosure relates to a method for operating a sensor described above and below, in which external sensor data is received from a neighboring sensor of the sensor network in a first communication mode of the communication module in the sensor. The sensor then switches the communication module from the first

Communication mode to the second communication mode, whereupon the received sensor data are sent to a receiver outside the sensor network in the second communication mode.

Another aspect of the present disclosure relates to a program element that, when executed on a processor of a sensor described above and below, instructs the sensor to perform the steps described above.

Another aspect of the present disclosure relates to a computer-readable medium on which a program element described above is stored.

The term "process automation in an industrial environment" can be understood as a branch of technology that includes measures for operating machines and systems without human involvement. One goal of process automation is to automate the interaction of individual components of a plant in the chemical, food, pharmaceutical, petroleum, paper, cement, shipping or mining sectors. A variety of sensors can be used for this purpose, which are particularly adapted to the specific requirements of the process industry, such as mechanical stability, insensitivity to contamination, extreme temperatures and extreme pressures. Measured values from these sensors are usually transmitted to a control room, in which process parameters such as fill level, limit level, flow, pressure or density are monitored and settings for the entire plant can be changed manually or automatically.

A sub-area of process automation in the industrial environment concerns the logistics automation of plants and the logistics automation of supply chains. With the help of distance and angle sensors, processes inside or outside a building or within a single logistics plant are automated in the field of logistics automation. Typical applications include logistics automation systems in the area of baggage and freight handling at airports, in the area of traffic monitoring (toll systems), in retail, in parcel distribution or in the area of building security (access control). What the examples listed above have in common is that presence detection in combination with precise measurement of the size and position of an object is dependent on the respective Application-side sensors can be used for this purpose based on optical measurement methods using lasers, LEDs, 2D cameras or 3D cameras that measure distances according to the time of flight (ToF) principle.

Another area of process automation in the industrial environment concerns factory-to-production automation. Applications for this can be found in a wide variety of industries such as automobile manufacturing, food production, the pharmaceutical industry or in the packaging sector in general. The aim of factory automation is to automate the production of goods using machines, production lines and/or robots, i.e. to allow it to run without human involvement. The sensors used here and the specific requirements with regard to measurement accuracy when recording the position and size of an object are comparable to those in the previous example of logistics automation.

The terms used in the claims should be construed to give them the broadest reasonable interpretation consistent with the foregoing description. For example, the use of the article "a" or "the" in introducing an element should not be construed to exclude a plurality of elements. Similarly, the mention of "or" should be construed to include a plurality of elements, so that the mention of "A or B" does not exclude "A and B" unless it is clear from the context or the preceding description that only one of A and B is meant. Further, the phrase "at least one of A, B and C" is to be understood as one or more elements from a group of elements consisting of A, B and C, and not to be construed to require at least one of each of the listed elements A, B and C, whether A, B and C are related as categories or in some other way. Furthermore, the mention of "A, B and/or C" or "at least one of A, B or C" should be construed to include any single entity of the listed elements, e.g. A, any subset of the listed elements, e.g. A and B, or the entire list of elements A, B and C.

In the following, further embodiments of the present disclosure are described with reference to the figures. In the following description of the figures, If the same reference symbols are used, these designate identical or similar elements. The representations in the figures are schematic and not to scale.

Short description of the characters

Fig. 1 shows a sensor network according to an embodiment of the present disclosure.

Fig. 2 shows a sensor network according to another embodiment of the present disclosure.

Fig. 3 shows a sensor of a sensor network according to an embodiment of the present disclosure.

Fig. 4 shows a flowchart of a method according to an embodiment of the present disclosure.

Detailed description of embodiments

Fig. 1 shows a sensor network 1000 according to an embodiment of the present disclosure. The sensor network 1000 has a sensor 100 that can take on the role of the gateway in the sensor network. A plurality of further sensors 200 are provided that can communicate with each other and with the sensor 100 using a first communication mode. This can be a short-range communication mode. The sensor 100 can also communicate with a receiver 300 outside the sensor network 1000 using a second communication mode, for example a cloud, a server or a user's mobile device, such as a cell phone. The second communication mode is, for example, a cellular communication mode for long-range communication.

It is not necessary for each of the sensors 100, 200 to communicate individually with a corresponding cell tower. This has the advantage that not every sensor 100, 200 requires its own SIM card including a contract. Each sensor 100, 200 requires a complex radio setup (communication with cell towers, establishing a connection to the server/cloud, verification and/or encryption) before the data can be sent. Establishing a connection to the cloud 300 sometimes requires a larger amount of data than is later transmitted in the form of measurement data. This is inefficient and costs energy, time and data volume and leads to increased utilization of the cell network, which is also reflected in the energy consumption of the respective sensor. In addition, the server may have to communicate with many devices at the same time, which can also lead to increased utilization and increased energy requirements.

One embodiment of the present disclosure combines the data from multiple sensors 200 into one sensor 100 so that they can then be sent together from the sensor 100 to the server or cloud.

The sensors 100, 200 communicate with each other and decide based on defined parameters, if required supported by artificial intelligence, which device takes on the role of the gateway. Alternatively, a standalone gateway 400 can be used specifically for this purpose. This is shown in Fig. 2. An example of such an additional gateway is the VEGAMET from VEGA.

The communication standard DECT NR+ can be used as a communication mode for communication between the sensors 100, 200, which offers basic support for flexible handling of gateways.

Fig. 3 shows a sensor 100 with a sensor housing in which the processor 102 is located. A communication module 101 is connected to the processor 102, which has a wireless communication interface and a wired communication interface. Only one such communication interface can also be provided.

Also connected to the processor 102 are a memory unit 104 for storing the received sensor data, as well as a sensor system 103 for recording the (own) sensor data, for example in the form of a radar circuit with antenna. Not every sensor 100, 200 sends its measured value (temperature, pressure, distance, fill level, etc.) (“sensor data”) independently to the Cloud 200. The sensors communicate with each other.

The measured values can be collected in a sensor 100 and then bundled and sent together to the cloud. This collection can include a time delay. The permissible delay of the measured values is adjustable.

The measured value can be sent to the gateway and forwarded from there without delay.

It is also possible for the measured values to be encrypted so that the gateway only has/passes on encrypted measured values from other sensors.

The cloud 300 can then forward data to the individual sensors 200 via the gateway (100, 400).

The sensors can communicate with each other, which also allows for flexible switching of the gateway.

A change of gateway is triggered by external circumstances of the device (so-called trigger events), among other things. The external circumstances include things such as reception strength, signal quality, network coverage of the mobile operator, availability/signal quality of individual mobile standards (NB-loT or CAT-M1), condition of the battery or energy storage, available data volume, amount of data to be sent, existing mobile connection (no connection establishment necessary), data utilization in relation to the owner of the device (in the case of automatic communication between devices of different owners), existing connection to the server or cloud (no transmission of keys; authentication, etc. necessary), instruction from the server that a different gateway is to be used (the sensor or gateway that is currently being used is exchanged/replaced), regularly occurring external circumstances such as change of location, temperature fluctuations, energy availability (solar cells) or Shutdowns that affect the gateway function can be taken into account. AI (or machine learning) can detect and also predict such events.

In addition to the actual measured values, position data or other useful data (e.g. GPS, A-GPS) can also be shared with other participants.

Devices that cannot determine a GPS position (not working or function impaired by the environment, inside a building) can thus find out the approximate position. Shared/available A-GPS data makes it easier to share your own position. Other useful data can be the mobile phone coverage of individual mobile phone operators in the region. Failure of a mobile phone network or a mobile phone band so that another mobile phone network is used.

Grouping several sensors can be done manually at the beginning. An automatic search for compatible devices is also possible. This can include the devices of a single owner, but also the devices of different owners who do not know each other.

A gateway change can be supported and improved by AI or machine learning.

The use of a gateway is optionally adjustable or can be changed. The sensor, the gateway and also the server can decide for themselves (if necessary with the support of the Kl) whether the use of a gateway is necessary/useful.

The sensor can communicate directly with the server at regular/irregular times to avoid unnecessary load on the gateway. This can be the case when there is a software update or exchange of new certificates/keys, or when a message needs to be sent as quickly as possible.

The gateway can be used as a buffer if a sensor is already ready to communicate or if several sensors require identical data (software update). This enables more efficient operation and consequently a longer battery life of the sensors.

Each sensor can have a unique ID that cannot be changed, as well as a flexible ID to cyclically anonymize devices.

The communication between the sensors may not be limited to wireless DECT NR+. Other interfaces such as Bluetooth, Hart, Ethernet, etc. may also be provided.

It can be considered a core aspect of the present disclosure that several sensors collect their messages at one point (the sensor 100 or the gateway 400) in order to send them as efficiently as possible in terms of energy consumption and transmission time. Instead of as before (each sensor sends individually), the messages are bundled at an optimal point, which then acts as a gateway, and sent from there.

For example, there is a group of self-contained NB-loT sensors mounted within an area. Each of these devices wakes up at a set time and sends a measured value to the cloud.

In order to optimize this process, the energy-intensive transmission of measured values via mobile communications should be reduced. To do this, the sensors communicate with each other and determine which sensor is best suited to transmit the measured values of the entire group in the current situation. This type of communication can be activated by a signal (wired or another radio signal). This can save further energy.

The selected device 100 is the only device that establishes a connection to the cloud and transmits all measured values. Alternatively, operation with a permanently installed gateway 400 (e.g. VEGAMET) is also possible. This allows the devices to completely dispense with mobile communication. The sensors 100, 200 then communicate directly with the gateway, which takes over all further communication. If the permanently installed gateway 400 fails, the data can be sent to the cloud via a newly defined gateway 100 (formerly sensor).

The selection of the “optimal gateway” is not carried out in a fixed order, but is parameter-based.

Fig. 4 shows a flow chart of a method according to an embodiment of the present disclosure. In step 401, the sensors of a sensor network collect sensor data. This is then transmitted to a sensor of the sensor network in step 402 using short-range communication and collected there. This transmission can also take place step by step from sensor to sensor until it has arrived at the appropriate sensor. In step 403, this sensor changes its communication mode from short-range communication between the sensors to long-range communication and transmits the collected and its own sensor data to an external receiver, for example a cloud or a cell tower, in step 402.

Claims

patent claims

1. Field device (100) of a sensor network (1000), set up for process automation in an industrial or private environment, comprising: at least one communication module (101), set up to receive external sensor data from a neighboring sensor (200) of the sensor network in a first communication mode; wherein the communication module is further set up to send the received sensor data to a receiver (300) outside the sensor network in a second communication mode; a processor (102), set up to switch the communication module from the first communication mode to the second communication mode.

2. Field device (100) according to claim 1, wherein the processor (102) is configured to decide whether the own sensor data acquired by the sensor (100) are sent by the communication module (101) to the neighboring sensor (200) in the first communication mode, or to the receiver (300) in the second communication mode.

3. Field device (100) according to one of the preceding claims, wherein the processor (102) is configured to switch the communication module (101) regularly or as needed from the first communication mode to the second communication mode.

4. Field device (100) according to one of the preceding claims, wherein the processor (102) is configured to switch the communication module (101) from the first communication mode to the second communication mode based on a trigger event by the adjacent sensor (200).

5. Field device (100) according to one of the preceding claims, configured as a buffer for the external sensor data.

6. Field device (100) according to one of the preceding claims, configured to simultaneously send the external sensor data and the own sensor data to the receiver (300).

7. Field device (100) according to one of the preceding claims, wherein the first communication mode is set up according to one or more of the network protocols Bluetooth LE, LoRa, Symphony Link, weightless, Wi-Fi, HaLow, DECT ULE, DECT NR+, M-Bus Wireless, Wireless HART, Matter, Thread, Zigbee, or Mioty.

8. Field device (100) according to one of the preceding claims, wherein the second communication mode is set up according to one or more of the communication standards 1G, 2G, 3G, 4G, 5G, LoRa, Sigfox, Waviot, RPMA, NB-IOT, LTE-M, or CAT-M1.

9. Field device (100) according to one of the preceding claims, wherein the processor (102) is further configured to delete the foreign sensor data after sending.

10. Field device (100) according to one of the preceding claims, wherein the sensor is a level sensor, a limit level sensor, a pressure sensor or a flow sensor.

11. Sensor network (1000) comprising a plurality of field devices (100) according to one of claims 1 to 10.

12. Sensor network (1000) according to claim 11, further comprising a gateway (400).

13. Use of a gateway (400) for a sensor network (1000) according to one of claims 11 or 12.

14. A method for operating a field device (IOO) according to one of claims 1 to 10, comprising the following steps: Receiving external sensor data from a neighboring field device (200) of the sensor network (1000) in a first communication mode of the communication module (101);

Switching the communication module from the first communication mode to the second communication mode;

Sending the received sensor data to a receiver (300) outside the sensor network in the second communication mode.

15. A program element which, when executed on a processor (102) of a field device (100) according to any one of claims 1 to 10, instructs the sensor to perform the steps according to the method of claim 14.

16. A computer-readable medium on which a program element according to claim 15 is stored.