Method for operating radio positioning system, radio positioning system and transponder

Abstract

The invention relates to a radio positioning system in which the position of a transponder (201) is determined by means of a plurality of base stations (101-103) of the radio positioning system using a radio signal reception time difference or using a radio signal propagation time. The transponder is arranged at a selected point on the object (200) to be positioned. Furthermore, the transponder is equipped with a communication module for the wireless communication system, and the transponder operates as a base station or master station of the wireless communication system. At least one display unit (202), which is provided with a communication module and is separate from the transponder, is connected to the transponder as a subscriber station or slave station of the wireless communication system. The transponder transmits object-related data (401) and position-related information sent by a base station of the radio positioning system to the display unit. The display unit displays the transmitted position-related information and object-related data in a continuously updated manner.

Description

Technical Field

[0001] The invention relates to a method for operating a radiolocation system, as well as to a radiolocation system and a transponder for carrying out the method. Background Art

[0002] Radio-based locating devices can be based, for example, on RFID tags (radio frequency identification), which are respectively attached to objects for identification or locating. RFID tags include a storage unit, the content of which can be read by an RFID reader and can also be changed. Usually, at least one identifier is stored in each RFID tag. In order to read the information stored in the RFID tag, the RFID reader sends a request signal by generating an electromagnetic alternating field. On the one hand, this electromagnetic alternating field is used to power, in particular, passively operated RFID tags, which have no energy source of their own. On the other hand, the RFID tag transmits a response signal by modulating the electromagnetic alternating field, for example by load modulation or changing its antenna impedance.

[0003] Wireless positioning systems for industrial automation systems must meet special requirements such as reliable data transmission, authenticity of the transmitted data and insensitivity to interference sources. Since industrial automation systems are used to monitor, control and regulate technical processes, especially in the fields of manufacturing, process and building automation, a disturbed, manipulated or incorrectly configured wireless positioning system can have serious consequences and, in the worst case, can lead to downtime of the automation system.

[0004] EP 3 599 573 B1 relates to a method for transmitting data between a wireless transponder reader and a wireless transponder, wherein a control unit of the wireless transponder controls the change of the load impedance to generate a response signal by means of a control signal, the control signal having a selected switching pulse frequency and a selected number of switching pulses. The control unit encodes a multi-valued symbol of at least three values ​​into the control signal. The symbol values ​​are respectively assigned to switching pulse sequences, each sequence having a unique combination of switching pulse frequency, number of switching pulses and phase shift. Only those combinations are selected whose quotient of the number of switching pulses and the switching pulse frequency is within a predetermined value range.

[0005] According to WO 2022 / 002503A1, a radio positioning system is known, in which the position of a transponder is determined by a plurality of base stations of the radio positioning system in a first operating mode according to the difference in the reception time of the radio signal, or in a second operating mode according to the propagation time of the radio signal. In order to determine its position, the transponder sends a message to the base station by broadcasting. The base stations receiving the message each determine the received signal strength of the transponder signal used to transmit the message. An evaluation device determines the number of base stations whose received signal strength exceeds a predetermined minimum signal strength and places the base station in the first or second operating mode accordingly.

[0006] KR20180070861A relates to a location information terminal, which includes a bracket, on which at least one electronic shelf label is arranged, and a first communication unit arranged on the bracket, which receives identification information of at least one electronic shelf label. In addition, a control unit is provided for generating location information for the location information terminal. The second communication unit sends the identification information and the location information to a gateway. The second communication unit can be arranged, for example, in the bracket or on the surface of the bracket. Therefore, at least one gateway or at least one server can automatically receive the identification information from the electronic shelf label and register the identification information of at least one electronic shelf label.

[0007] The transponders of wireless positioning systems are specifically mounted on the object to be located, such as a workpiece, a robot or a vehicle, and transmit positioning signals at defined time intervals. In addition, the transponders can include electronic ink or electronic paper displays on which information related to the position, object or process status can be displayed in a human- or machine-readable manner. This enables, for example, the reliable and efficient tracking and processing of vehicle bodies in automobile production lines. Since vehicle bodies usually consist largely of metal, transponders should only be placed at appropriate locations on the vehicle body in order to minimize radio signal attenuation. On the other hand, the electronic ink or electronic paper display of a transponder equipped with a corresponding display should always be easy to read by personnel on the production line. Summary of the invention

[0008] The object of the present invention is therefore to provide a method for operating a radiolocation system which enables advantageous positioning of transponders with respect to radio signal propagation while ensuring good readability of the associated display unit, and to provide means or implementations suitable for carrying out the method.

[0009] This object is achieved according to the invention by a method having the features of claim 1, a radiolocation system having the features of claim 11 and a transponder having the features of claim 12. Advantageous developments of the invention are given in the dependent claims.

[0010] According to the method of the present invention, the position of the transponder is determined by a plurality of base stations of the radio positioning system according to the time difference of receiving the radio signal or the propagation time of the radio signal. The base stations are arranged at predetermined positions respectively. The transponder is arranged at a selected point on the object to be positioned. In addition, at least one identifier assigned to the object to be positioned is stored in the transponder, and when the position of the transponder is determined, the identifier is transmitted to the base station of the radio positioning system. Based on the identifier, the base station of the radio positioning system transmits the object-related data assigned to the object to be positioned to the transponder. The base station of the radio positioning system preferentially transmits the continuously updated object-related data to the transponder.

[0011] For example, the position of the transponder can be determined based on the time difference of arrival (TDOA), wherein the base stations of the radio positioning system are time synchronized with each other. In principle, the position of the transponder can also be determined based on two-way ranging (TWR). Preferably, the radio positioning system is at least based on RFID, UWB or a real-time location system (RTLS) in the 2.4 GHz ISM band.

[0012] According to the present invention, the transponder is equipped with a communication module for a wireless communication system and operates as a base station or master station of the wireless communication system. In addition, at least one display unit equipped with the communication module and separated from the transponder is provided, and the display unit is connected to the transponder as a user station or slave station of the wireless communication system. The transponder transmits position-related information and object-related data sent by the base station of the wireless positioning system to the display unit via the wireless communication system. The display unit displays the transmitted position-related information and object-related data in a continuously updated manner.

[0013] By means of the invention, the transponder can be optimally positioned at the object to be positioned for the transmission of a wireless positioning signal. In contrast, the display unit, in particular the electronic paper display device, can be arranged by means of its decoupling device so that the relevant information can be easily and correctly read by a personnel or machine identification system when processing the individual objects in the production line. In principle, it is also possible to couple multiple display units to one transponder, for example by using a positioning manager, in order to ensure clear readability at all times even under complex conditions of use. In addition, battery-powered display units can be replaced simply and quickly by display units with rechargeable batteries.

[0014] According to a preferred embodiment of the present invention, the wireless communication system is a Wi-Fi communication system or a Bluetooth communication system. The transponder and the display unit can communicate via a Wi-Fi direct connection. In contrast, the display unit preferably communicates with the base station of the radio positioning system only indirectly via the transponder. Therefore, the display unit does not adversely affect the communication within the radio positioning system.

[0015] The radio positioning system according to the present invention is used to execute the method in the aforementioned embodiment, and includes at least one transponder equipped with a communication module of a wireless communication system, which can be arranged at a selected point on the object to be positioned and can operate as a base station or a master station of the wireless communication system. In addition, there is at least one display unit equipped with a communication module, which is separated from the transponder and can be connected to the transponder as a user station or a slave station of the wireless communication system. In addition, the radio positioning system also includes a plurality of base stations that can be arranged at predetermined positions, which are used to determine the position of the transponder based on the radio signal reception time difference or the radio signal propagation time.

[0016] The transponder of the radiolocation system according to the invention is configured and designed to store at least one identifier assigned to the object to be located and transmit it to the base station of the radiolocation system when the position of the transponder is determined. In contrast, the base station of the radiolocation system is respectively configured and designed to transmit object-related data assigned to the object to be located to the transponder based on the identifier. In addition, the transponder is configured and designed to transmit the position-related information and the object-related data transmitted by the base station of the radiolocation system to the display unit. Therefore, the display unit is configured and designed to display the transmitted position-related information and object-related data continuously updated.

[0017] The transponder according to the present invention is designed to perform the method corresponding to the aforementioned embodiment and is equipped with a communication module for a wireless communication system. In addition, the transponder can be arranged at a selected point on the object to be located and can operate as a base station or a master station of the wireless communication system. In addition, the transponder is configured and designed so that at least one display unit equipped with a communication module and separated from the transponder can be connected to the transponder as a user station or a slave station of the wireless communication system.

[0018] Furthermore, the transponder according to the present invention is configured and designed so that a plurality of base stations respectively arranged at predetermined positions can detect the position of the transponder based on the radio signal reception time difference or the radio signal propagation time. Furthermore, the transponder is configured and designed to store at least one identifier assigned to the object to be located and transmit it to the base station of the radio positioning system when the transponder position is determined. Finally, the transponder is configured and designed to transmit the position-related information and the object-related data sent by the base station of the radio positioning system and assigned to the object to be located based on the identifier to the display unit for continuously updated display. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] The present invention will be described in detail by an embodiment in conjunction with the accompanying drawings. The drawings show:

[0020] Figure 1 A radio positioning system for an industrial automation system is shown, comprising a plurality of base stations, a transponder and a display unit coupled to the transponder and arranged at an object to be positioned.

[0021] Figure 2 A radiolocation system having a plurality of base stations, a transponder and a portable display unit is shown. DETAILED DESCRIPTION

[0022] In this embodiment Figure 1The radio positioning system shown is a real-time positioning system (RTLS) based on UWB or 2.4GHz ISM band, which includes multiple base stations 101-103, which are arranged at predetermined or known positions. With the help of base stations 101-103, the position of the RTLS transponder 201 is detected using the radio signal propagation time or the radio signal reception time difference, and the transponder is located at a selected point on the object 200 to be positioned. In this embodiment, the object 200 to be positioned is a vehicle in a vehicle production line. In order to exchange the best positioning signal 100 with the base station, the RTLS transponder 201 is placed on the top of the vehicle body. In addition to the UWB or 2.4GHz ISM band components, the radio positioning system can also include additional components for GPS, WLAN or inertial sensor-based positioning. Here, multiple or all of these components can be integrated into the RTLS transponder 201 and the base stations 101-103 of the radio positioning system.

[0023] In the RTLS transponder 201, at least one object identifier assigned to the object to be located 200 is stored, which object identifier is transmitted to the base stations 301-303 of the radio positioning system when determining the position of the RTLS transponder 201. In this way, for example, it is possible to monitor the object to be located 200, which is transported and assembled by robots 411, 421 in a production line. The robots 411, 421 are controlled by programmable logic controllers 410, 420, respectively, which are connected to a central monitoring and control unit 400. In particular, the programmable logic controllers 411, 421 and the radio positioning system can be configured or monitored by means of the monitoring and control unit 400.

[0024] The base stations 101-103 are connected to an evaluation device of the radio positioning system configured as a gateway 300. The base stations 101-103 preferably send datagrams 301-303 to the gateway 300 for evaluation, the datagrams comprising detected signal propagation time information, signal reception time information, signal strength measurements or object identifiers of the received positioning signals 100. For this purpose, in particular, the positions of the base stations 301-303 of the radio positioning system are present in the gateway 300 or the monitoring and control unit 400.

[0025] In the present embodiment, the position of the RTLS transponder 201 is determined based on the time difference of arrival (TDOA). To this end, the base stations 101-103 are time synchronized with each other. Alternatively, the position of the RTLS transponder 201-203 or the respective distance of the RTLS transponder 201 to the base station 101-103 can be determined based on two-way ranging (TWR). For example, detailed information about position determination by TDOA can be described in an example form under multi-point positioning (https: / / en.wikipedia.org / wiki / Multilateration) on Wikipedia.

[0026] For example, if at least 4 base stations receive positioning signals with a required minimum signal strength from RTLS transponder 201, gateway 300 can place base stations 101-103 in TDOA operation mode. However, if 3 base stations receive positioning signals with a required minimum signal strength from RTLS transponder 201, gateway 300 can place the base stations in TWR operation mode. In addition, gateway 300 can use knowledge of neighboring relationships between base stations or the locations of base stations to decide to switch between TDOA and TWR operation modes.

[0027] The gateway 300 of the radio positioning system sends the position of the respective determined RTLS transponder 201, including the object identifier, to the monitoring and control unit 400. For example, the monitoring and control unit 400 can use the position of the RTLS transponder 201 sent by the gateway 300 to verify the positioning information assigned to the RTLS transponder 201 in the monitoring and control unit 400. In addition, object-related data 401 assigned to the object to be located are sent to the RTLS transponder 201 by the base stations 101-103 of the radio positioning system based on the object identifier. These object-related data 401 are preferably provided by the monitoring and control unit 400. Preferably, the continuously updated object-related data 401 are transmitted to the RTLS transponder 201 by the base stations 101-103 of the radio positioning system.

[0028] The RTLS transponder 201 is equipped with a communication module for a wireless communication system, and the transponder operates as a base station or a master station of the wireless communication system. The wireless communication system can be a Wi-Fi communication system or a Bluetooth communication system.

[0029] Furthermore, at least one display unit 202 is provided which is equipped with a communication module and is separate from the RTLS transponder 201 and which is connected as a user station or slave station of the wireless communication system to the RTLS transponder 201. The display unit is preferably configured as an electronic paper display device and communicates only indirectly, i.e., via the RTLS transponder 201, with the base stations 101-103 of the radio positioning system.

[0030] exist Figure 1 In the illustrated embodiment, the display unit 202 is fixed to the vehicle door, so that personnel on the production line can easily read or detect through a scanner the information displayed on the display unit 202. Basically, the display unit 202 can also be arranged at different locations on the vehicle body, which provide good visibility for personnel on the production line.

[0031] The RTLS transponder 201 transmits the object-related data 401 and the position-related information sent by the base stations 101-103 of the radio positioning system to the display unit 202 via the wireless communication system. Here, the RTLS transponder 201 and the display unit 202 preferably communicate with each other via a Wi-Fi direct connection. The display unit 202 displays the transmitted position-related information and the object-related data in a continuously updated manner.

[0032] exist Figure 2 In the illustrated embodiment, in addition to the display unit 202 fixed to the object to be located 200, a portable display unit 202' is also used, which can be configured as a tablet computer, for example. In this embodiment, the object to be located 200 is contained in containers arranged in a plurality of areas 1-3, in particular in a storage area, and the containers are used to store materials or production products. RTLS transponders 201 are fixed to these containers 200, respectively, and as mentioned above, the transponders can be located by base stations 101-104 of the radio positioning system.

[0033] When a person passes through areas 1-3, his portable display unit 202' is connected to the RTLS transponder 201 of the container 200 located in each area 1-3 via a communication connection of the wireless communication system (similar to the above-mentioned design scheme). Therefore, in addition to being displayed on the display unit 202 fixed to the container 200, location-related information and object-related data can also be displayed on the portable display unit 202' in each area 1-3. In the present embodiment, these location-related information and object-related data particularly include indications of the various areas 1-3 and a list of the contents of each container. In principle, the display unit 202 fixed to each container 200 can also be connected to the RTLS transponder 201 there via a wired connection. The key is that the communication between the portable display unit 202' and the RTLS transponder is realized through the wireless communication system, for which the RTLS transponder 201 operates as a base station or master station.

Claims

1. A method for operating a radio positioning system, wherein: - determining the position of the transponder (201) by means of a plurality of base stations (101-103) of the radio positioning system using a radio signal reception time difference and / or using a radio signal propagation time, wherein the base stations are respectively arranged at predetermined positions, - the transponders are arranged at selected points on the object (200) to be located, - storing in the transponder at least one identifier assigned to the object to be located and transmitting the identifier to the base station of the radiolocation system when the position of the transponder is determined, - based on the identifier, sending object-related data (401) assigned to the object to be located to the transponder by means of the base station of the radiolocation system, - the transponder is equipped with a communication module for a wireless communication system and the transponder operates as a base station or master station of the wireless communication system, at least one display unit (202) equipped with a communication module and separate from the transponder is connected to the transponder as a user station or slave station of the wireless communication system, - the transponder transmits the object-related data and position-related information sent by the base station of the radiolocation system to the display unit, - the display unit displays the transmitted location-related information and the object-related data in a continuously updated manner.

2. The method according to claim 1, wherein: The position of the transponder is determined based on a time difference of arrival, and wherein the base stations of the radiolocation system are time synchronized with each other.

3. The method according to claim 1 or 2, wherein The position of the transponder is determined based on two-way ranging.

4. The method according to any one of claims 1 to 3, wherein: The radio positioning system is a real-time positioning system based at least on RFID, based on UWB and / or based on the 2.4 GHz ISM frequency band.

5. The method according to any one of claims 1 to 4, wherein: The wireless communication system is a Wi-Fi communication system or a Bluetooth communication system.

6. The method according to claim 5, wherein: The transponder and the display unit communicate with each other via a Wi-Fi direct connection.

7. The method according to any one of claims 1 to 6, wherein: The transponder transmits the position-related information and the object-related data to the display unit via the wireless communication system.

8. The method according to any one of claims 1 to 7, wherein: The continuously updated object-related data are transmitted to the transponder by means of the base station of the radio positioning system.

9. The method according to any one of claims 1 to 8, wherein: The display unit is an electronic paper display device.

10. The method according to any one of claims 1 to 9, wherein: The display unit communicates only indirectly with the base station of the radio positioning system by means of the transponder.

11. A radio positioning system for performing the method according to any one of claims 1 to 10, comprising: - at least one transponder (201) equipped with a communication module for a wireless communication system and capable of being arranged at a selected point on the object (200) to be located and capable of operating as a base station or master station of the wireless communication system, at least one display unit (202) equipped with a communication module, said display unit being separate from said transponder and being connectable to said transponder as a user station or slave station of said wireless communication system, - a plurality of base stations (101-103) which can be arranged at predetermined positions respectively, the base stations are used to detect the position of the transponder by using a radio signal reception time difference and / or by using a radio signal propagation time, -in, the transponder being configured and designed to store at least one identifier assigned to the object to be located and to transmit the identifier to the base station of the radiolocation system when the position of the transponder is determined, - wherein the base station of the radiolocation system is configured and designed to transmit object-related data (401) assigned to the object to be located to the transponder based on the identifier, - wherein the transponder is further configured and designed to transmit the object-related data and position-related information sent by the base station of the radiolocation system to the display unit, - wherein the display unit is configured and designed to display the transmitted location-related information and the object-related data in a continuously updated manner.

12. A transponder for carrying out the method according to any one of claims 1 to 10, wherein: The transponder - equipped with a communication module for a wireless communication system, - can be arranged at a selected point on the object to be located, and said transponder can operate as a base station or master station of said wireless communication system, - is configured and designed to connect at least one display unit which is equipped with a communication module and is separate from the transponder to the transponder as a subscriber station or slave station of the wireless communication system, - is further configured and designed so that a plurality of base stations arranged at predetermined positions detect the position of the transponder using a radio signal reception time difference and / or using a radio signal propagation time, - is also configured and designed to store at least one identifier assigned to the object to be located and to transmit the identifier to the base station of the radiolocation system when the position of the transponder is determined, - is also configured and designed to transmit object-related data and position-related information sent by the base station of the radiolocation system to the display unit for continuously updated presentation, the object-related data being assigned to the object to be located based on the identifier.

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