DE102018117525B4 - Method and device for position determination based on a UWB radio network - Google Patents

Abstract

Method for determining position and for communication based on a UWB radio network (Ultra Wide Band), with a plurality of anchors (UWB transceiver with known position) (14, 15, 16, 17, 18, 19, 20), as well as with at least one day (mobile UWB transceiver) (24, 25, 26, 27, 28), which is connected to the anchors (14, 15, 16, 17, 18, 19, 20) and with other tags (24, 25, 26, 27, 28), if available, forms the participants (14, 15, 16, 17, 18, 19, 20, 24, 25, 26, 27, 28) of the UWB radio network, with a position determination of the tags (24, 25 , 26, 27, 28) is carried out according to the TWR method (two way ranging), communication between the participants (14, 15, 16, 17, 18, 19, 20, 24, 25, 26, 27, 28), a switchover between a position determination mode for position determination of tags (24, 25, 26, 27, 28) with blocking of the participants (14, 15, 16, 17, 18, 19, 20, 24 , 25, 26, 27, 28) and an Em pfangs Modus for receiving data from other participants (14, 15, 16, 17, 18, 19, 20, 24, 25, 26, 27, 28) with a certain switching frequency, and wherein the position determination mode has a fixed duration and the reception mode one has variable duration.

Description

The invention relates to a method and a device for determining the position based on a UWB radio network (Ultra Wide Band) with a plurality of anchors (UWB transceiver with known position), as well as with at least one day (movable UWB transceiver) that with the Anchors and other tags, if available, form the participants in the UWB radio network, with the tags being determined using the TWR method (two-way ranging).

In industry and especially in intralogistics, localization of the different dynamic participants (driverless transport systems, forklifts, people, goods carriers, goods, etc.) plays a crucial role. The position data of the participants are relevant at almost every access point: While, for example, a monitoring person or a control system needs all position data brought together from a central point, individual participants, such as a robot, need their own position locally for autonomous navigation. Furthermore, the transmission of the position data between the individual participants is of considerable importance: for example, two autonomous vehicles can negotiate a traffic situation with each other, for example, or a rushing forklift warns a person coming around the corner. Thus, in addition to the position determination technology, communication technology is required for the exchange of information. The exchange of information about the position data is usually very time-critical (e.g. two vehicles approach each other). This means that communication that is as close to real time as possible is desirable.

Previous technical communication options, for example based on WLAN, Bluetooth, etc., aim to transmit as much data as possible in the shortest possible time. The focus is therefore on increasing data rates and secure data transmission (i.e. additional time-consuming protocol procedures).

If there is an exchange of information between more than just two communication participants, the exchange usually takes place via a central contact point in a roundabout way: For example, in a WLAN network, the information is transmitted via a WLAN router, even if the message is sinked is in close proximity to the source. The message arrives at the destination after a long delay due to detours and additional protocol procedures (routing of data distribution, handshake procedures). During this time, for example, two vehicles could move towards one another in an uncontrolled manner, since the mutual position data are only transmitted after a delay. An additional disadvantage of a classic communication network is that everyone involved needs a stable connection to the WLAN router. If at least one communication participant has no connection to the WLAN router, no communication is possible, even if there is a direct line of sight between the participants.

According to the US 7,372,968 B2 A device and a method for determining the position of subscribers who are provided with an RFID tag and the position of the subscribers in a predetermined spatial area are known. For this purpose, a movable RFID reader is used, for example, to detect which of the participants is in its reading area. The relevant RFID tag is read when the participant is in the reading area in order to obtain the special identification of the participant and to determine the position, the determined position of the participating tags being determined and stored in a database relating to the position information contains the participants involved.

With such a method and such a device, only RFID tags in the surroundings, i.e. within the RFID areas. The detection of the tags is then assigned to the position of the scanner.

The method and device in question are not suitable for time-critical, real-time monitoring of moving tags. The system is much too slow to avoid collisions between tags, for example, with numerous differently moving tags.

From the WO 2016/148818 A1 a method and a device for position determination and for communication based on a UWB radio network (Ultra Wide Band) are known, with a plurality of anchors (UWB transceivers with known positions), and with at least one day (movable UWB transceiver), that forms the participants of the UWB radio network with the anchors and with other tags, if available, the tags being determined using the TWR method, namely by means of RTT, communication between the subscribers taking place at least partially at the same time .

From the US 2016/0245716 A1 a calibration method for a barometer in a handset is also known, a barometric pressure sensor of the handset returning to a frequently visited position from which the height is known. The known height is then used to calibrate the barometric pressure sensor used to obtain height measurements based on raw data recorded by the barometric pressure sensor. The handset can be coupled to a computer on a motor vehicle so as to indicate a transport mode or to transmit other information related to the vehicle or its movement, such as position data, speed, direction of movement, inclination, etc.

From the DE 10 2016 217 532 A1 a mobile radio unit for improving traffic safety is also known, with at least one radio device for transmitting and / or receiving information by means of UWB to a radio station; with at least one communication means for sending and / or receiving information based on at least one communication technology that differs from the UWB technology; wherein the mobile radio unit is designed by means of the communication means for exchanging information with an object on which a holder for receiving the mobile radio unit is provided and / or a portable computing system carried by a road user. Here real-time communication and position determination take place.

Against this background, the invention is based on the object of specifying a method and a device for determining the position which, in addition to determining the position as quickly and precisely as possible, also enables communication as quickly as possible between the participants.

This object is achieved by a method according to claim 1.

The object of the invention is further achieved by a device according to claim 11.

The object of the invention is completely achieved in this way.

According to the invention, the position determinations and the communication take place on the basis of a UWB radio network. This enables a particularly precise position determination over relatively long ranges without the signals being disturbed by WLAN signals. As a result of using the TWR method, bidirectional communication between the participants is used to determine the position.

Conventional distance measurements based on UWB are basically possible in two ways: via the TDoA method or via the TWR method. In most cases, the TDoA method is used because it only enables unidirectional communication and therefore a higher number of tags can be localized. A disadvantage of the TDoA process is that the anchors have to be synchronized with one another.

Although fewer tags can be localized at the same rate using the TWR method according to the invention, synchronization of the anchors is not necessary. This is made possible by the fact that bidirectional communication between anchor and tag takes place in the TWR process. A distance measurement is preferably carried out by a signal transit time measurement.

In the bidirectional signal exchange between the participants involved, the data content of the signals is irrelevant since only the transit time is measured. However, according to the invention the transmitted signals are used for simultaneous data exchange.

In this way, the signals emitted for position determination are used simultaneously for communication, as a result of which a shortened total time for position determination and data transmission is achieved. A simplification of the overall system can also be achieved.

According to the invention, there is also a switchover between a position determination mode for determining the position of tags with blocking of the participants involved and a reception mode for receiving data from other participants with a specific sampling rate (switchover frequency), the position determination mode having a fixed duration and the reception mode having a variable duration. The switchover therefore takes place at a variable switchover frequency.

The switching frequency can therefore be adapted to the boundary conditions of the radio network, for example the number and maximum speed of the subscribers, the size of the radio network, etc. This ensures particularly effective and fast communication.

A maximum possible switching frequency naturally depends on the performance of the participants involved (processor performance, memory speed, etc.). It is preferred to work with the highest possible switching frequency, but a sufficient fault tolerance should be ensured.

In a preferred embodiment of the invention, all participants store data with a fixed data structure, which are communicated between the participants within the radio range.

The data exchange is based on a fixed data structure, for example in the form of a matrix facilitated. When exchanging data, only the values in the data structure need to be exchanged (eg new position data x, y, z of a specific day). If new data is received, the position data is replaced internally and sent on at the next opportunity.

During a measurement for determining the position between at least two participants, preferably by means of signal propagation time measurement, the transmitted data can preferably be received by other participants within the radio range.

For this purpose, during a measurement to determine the position between at least two participants, the participants involved are blocked from receiving further signals during the measurement, but the transmitted data can be received by other participants within the radio range.

This enables a highly effective use of the UWB radio network for position determination and for communication. Thus, the data is distributed during a signal transit time measurement (distance measurement) as from a radio tower to all surrounding participants in a direct and time-effective way. If a subscriber is again not in the signal transit time measurement (distance measurement), he is able to receive the data of the other subscribers who are not involved in the signal transit time measurement.

These states take place in a controlled change and enable real-time information exchange of all participants within the radio range.

The position is determined using the TWR method, preferably by measuring the signal transit time between a day and the anchor. At least three distances to three known positions are required for determining the position. For this purpose, signal delay measurements are carried out between the day and at least three anchors. The inclusion of additional anchors increases the accuracy of the measurement.

Furthermore, a position determination can include signal transit time measurements between one day and at least one other day with a known position.

This can also increase the accuracy.

The communicated data preferably includes at least the position data.

In addition, data relating to the speed and direction at which the tags move can be transmitted.

In addition, of course, further data can be transmitted, for example type of object, size and mass of the object on which the day was recorded.

According to a further embodiment of the invention, all the stored data of the subscribers are exchanged with all subscribers within the radio range.

Each participant thus knows all the information available to all participants (position data, but also other data). The system thus represents its own database, which is immediately available to every participant. This supports near-real-time use and enables fast reaction of moving participants, for example to avoid collisions.

In the device according to the invention, all subscribers are preferably designed to store data with a fixed data structure and to transmit the stored data between the subscribers within the radio range.

Furthermore, the subscribers are preferably designed to transmit data for communication to the other subscribers within the radio range during a measurement to determine the position between at least two subscribers, preferably by signal delay measurement.

In this case, the subscribers are preferably designed to communicate at least the position data, possibly additional data relating to the speed and direction at which the tags move.

Of course, further data can be transmitted.

As already mentioned, the subscribers are preferably designed to block these subscribers from receiving further signals during a transit time measurement between two subscribers, but to transmit the transmitted data of the subscribers involved in the transit time measurement from other subscribers within the radio range.

Finally, as already mentioned, all participants are preferably designed to exchange the stored data of the participants with all participants within the radio range.

It goes without saying that the features of the invention mentioned above and those yet to be explained below can be used not only in the combination specified in each case, but also in other combinations or on their own without departing from the scope of the invention.

Further features and advantages of the invention result from the following description of preferred exemplary embodiments.

• 1 ein UWB-Funknetz mit einer Reihe von Anchors und Tags, wobei die möglichen Kommunikationswege dargestellt sind;
• 2 das UWB-Funknetz gemäß 1, wobei das Verfahren zur Positionsbestimmung unter Verwendung einer Laufzeitmessung zu mindestens drei Anchors mit bekannter Position erfolgt;
• 3 das Funknetz gemäß 1, wobei der Mehrzweck einer direkten und echtzeitnahen Kommunikation zwischen den Teilnehmern angedeutet wird;
• 4 da Funknetz gemäß 1, wobei eine potentielle Verbreitung von Informationen zwischen zwei Teilnehmern, die nicht in Funkreichweite zueinander sind, über die übrigen Teilnehmer verdeutlicht ist;
• 5 eine vereinfachte schematische Darstellung des Aufbaus eines Anchors und
• 6 eine vereinfachte schematische Darstellung des Aufbaus eines Tags.

Show it:

• 1 a UWB radio network with a series of anchors and tags, the possible communication paths being shown;
• 2nd the UWB radio network according to 1 , the method for determining the position using a transit time measurement for at least three anchors with a known position;
• 3rd the radio network according to 1 , whereby the multipurpose of a direct and real-time communication between the participants is indicated;
• 4th because radio network according 1 , wherein a potential distribution of information between two participants that are not within radio range of one another is made clear about the other participants;
• 5 a simplified schematic representation of the structure of an anchor and
• 6 a simplified schematic representation of the structure of a day.

In 1 is a device according to the invention as a whole with the number 10th designated. The device 10th includes a room 12 , for example, a warehouse that faces out through a wall 11 is completed. Inside the room 12 are anchors on the edge 14 , 15 , 16 , 17th , 18th , 19th , 20th with a known position, preferably at regular intervals from one another.

Each anchor includes according to 5 a processor 56 that with a memory 58 as well as with a transceiver 60 is coupled, which is a combined transmitter and receiver for UWB signals. The transceiver 60 stands with an antenna 62 in connection, over which UWB radio signals can be transmitted and received.

One example is in a wall of the room 12 a movable door 13 provided with which the room 12 can be locked or opened to the outside. In the immediate vicinity of the door there is an anchor on the inside 7 provided that with a communication interface 22 communicates with the outside world.

Inside the room 12 are several moving objects as an example 30th , 31 , 32 , 33 shown, which are each provided with at least one day 24, 25, 26, 27, 28.

At the object 31 it is, for example, a carriage on which two tags 25, 26 are provided, so that for this object 31 not just the position, but also the orientation of the object 31 can be determined.

In the same way as with the Anchors 14 , 15 , 16 , 17th , 18th , 19th , 20th contains the example in 6 shown day 24 at least one processor 64 that with a memory 66 and a transceiver 68 is coupled. To the transceiver 68 is an antenna 70 connected to be able to send and receive UWB radio signals.

In 1 are with 35 possible communication channels between the Anchors 14 - 20th and indicated the day 24-28.

2nd exemplifies a position measurement on day 24.

Between day 24 and four anchors within range 14 , 15 , 19th , 20th become signal delay measurements 36 , 37 , 38 , 39 carried out, with which the distances to the four anchors 14 , 15 , 19th , 20th be determined. Using the known positions of the anchors 14 , 15 , 19th , 20th From this, the position of the tag 24 can be determined mathematically in a simple manner, for example using triliteration. The inclusion of more than three signal propagation time measurements (distance measurements) increases the accuracy.

During the signal runtime measurement or distance measurement (position determination mode), the participants involved, in the present case day 24 and the anchors 14 , 15 , 19th , 20th bound together and blocked for the reception of further signals. However, the transmitted data, which are not necessary for the runtime measurement, can also be received by other participants (tags and anchors) within the radio range. As a result, the data is distributed to all surrounding participants in a direct and particularly time-effective way, as if from a radio tower. If a subscriber is again not in the signal propagation time measurement mode for position determination, then he is able to receive the data of the other subscribers who do not participate in the signal propagation time measurement (receive mode).

Switching between these two modes is carried out regularly with a fixed but variable switching frequency, which enables real-time information exchange of all participants within the radio range. While the duration of the position determination mode is fixed, the duration of the reception mode is variable. The switchover can take place, for example, with a switchover frequency of 100 Hz to 1 kHz. It goes without saying that the maximum switching frequency depends, of course, on the performance of the subscribers concerned, that is to say anchors and tags, that is to say in particular on the performance of the processors concerned 56 , 64 , the associated memory 58 , 66 and the associated transceiver 60 , 68 depends. The switching frequency is chosen as high as possible, but sufficiently low to ensure a low error rate.

The data is stored for each participant with a fixed data structure, for example in the form of a specific matrix. This enables an easier and quick exchange of information between the participants 14 , 15 , 16 , 17th , 18th , 19th , 20th , 24th , 25th , 26 , 27th , 28 . When exchanging data, only the values in the data structure are exchanged (e.g. new position data x, y, z of the day 24th ). If new data is received, it will be replaced internally and sent on at the next opportunity (during the next distance measurement). Thus the distribution of the position data (but also more in the memory 66 of the day 24th stored data). Because the information sent by multiple participants 14 to 18th received and sent at the same time, the data also spread in several ways in parallel. This results in increased redundancy in data traffic. The communication distribution is similar to that of a meshed network architecture, but without a routing process. All stored data of the participants are preferred 15 to 28 exchanged with all participants within the radio range, which is facilitated by the fixed data structure. So every participant knows 14 to 28 all information (position data, possibly additional data about speed and direction at which the tags 24th to 28 move, and possibly further data). So every participant knows 14 to 28 all information real-time.

This advantage is demonstrated by 3rd clarifies. Here are the two objects 30th , 31 which is in a communication link 72 are on a collision course, as indicated by the arrows 41 and 42 is made clear. A quick evasive maneuver can thus be initiated.

The object 33 with day 28 is near the anchor 17th in front of the exit of the room 12 going through the door 13 is lockable. There is a communication movement 74 with the anchor 17th . The anchor 17th again stands with a communication interface 22 to the outside, via which the door can be opened and closed 13 can be controlled. The object 33 moves in the direction of an arrow 44 on the exit. Via the communication link 74 with the anchor 17th it ensures that the door 13 is opened so the object 33 can get out through the opening.

Based on 4th It is briefly clarified how communication can take place when two participants, tags 24, 28, are outside of the radio range from one another.

Tag 24 is in the state of a distance measurement for position determination. Thus, at this time, signals sent from day 24 can only be received by other participants. Tag 28 is in the receive mode, so it can receive signals from other participants. However, since the tag 28 is outside the radio range of the tag 24, communication takes place indirectly, such as through the communication links 46 , 47 , 48 , 49 , 50 , 51 , 52 , 53 , 54 It is indicated, via which all information on day 28 is transmitted.

Although the day 28 is outside the radio range of the day 24, the day 28 receives all information transmitted by the day 24.

Claims (17)

Method for determining position and for communication based on a UWB radio network (Ultra Wide Band), with a plurality of anchors (UWB transceiver with known position) (14, 15, 16, 17, 18, 19, 20), and at least one day (mobile UWB transceiver) (24, 25, 26, 27, 28), which is connected to the anchors (14, 15, 16, 17, 18, 19, 20) and with other tags (24, 25, 26, 27, 28), if available, forms the subscribers (14, 15, 16, 17, 18, 19, 20, 24, 25, 26, 27, 28) of the UWB radio network, with the tags (24, 25 , 26, 27, 28) is carried out according to the TWR method (two way ranging), communication between the participants (14, 15, 16, 17, 18, 19, 20, 24, 25, 26, 27, 28), a switchover between a position determination mode for position determination of tags (24, 25, 26, 27, 28) with blocking of the participants (14, 15, 16, 17, 18, 19, 20, 24 , 25, 26, 27, 28) and an Em pfangs Modus for receiving data from other participants (14, 15, 16, 17, 18, 19, 20, 24, 25, 26, 27, 28) with a certain switching frequency, and wherein the position determination mode has a fixed duration and the reception mode has a variable duration. Procedure according to Claim 1 , in which all participants (14, 15, 16, 17, 18, 19, 20, 24, 25, 26, 27, 28) store data with a fixed data structure that is shared between the participants (14, 15, 16, 17, 18, 19, 20, 24, 25, 26, 27, 28) can be communicated within the radio range. Procedure according to Claim 1 or 2nd , in which during a measurement to determine the position between at least two participants (14, 15, 16, 17, 18, 19, 20, 24, 25, 26, 27, 28), preferably by signal delay measurement, the transmitted data from other participants (14 , 15, 16, 17, 18, 19, 20, 24, 25, 26, 27, 28) can be received within the radio range. Procedure according to Claim 3 , in which during a measurement to determine the position between at least two participants (14, 15, 16, 17, 18, 19, 20, 24, 25, 26, 27, 28) the participants (14, 15, 16, 17, 18 , 19, 20, 24, 25, 26, 27, 28) are blocked during the measurement for the reception of further signals, but the transmitted data from other participants (14, 15, 16, 17, 18, 19, 20, 24, 25, 26, 27, 28) can be received within the radio range. Method according to one of the preceding claims, in which a position is determined by signal transit time measurements between a day (24, 25, 26, 27, 28) and anchors (14, 15, 16, 17, 18, 19, 20). Method according to one of the preceding claims, in which a position determination includes signal delay measurements between one day (24, 25, 26, 27, 28) and at least one other day (24, 25, 26, 27, 28) with a known position. Procedure according to Claim 6 , in which at least the position data belong to the communicated data. Procedure according to Claim 7 , in which data relating to the speed and direction at which the tags (24, 25, 26, 27, 28) move are additionally transmitted. Method according to one of the preceding claims, in which all stored data of the participants (14, 15, 16, 17, 18, 19, 20, 24, 25, 26, 27, 28) with all participants (14, 15, 16, 17 , 18, 19, 20, 24, 25, 26, 27, 28) can be exchanged within the radio range. Method according to one of the preceding claims, in which the communication and position determination between the participants (14, 15, 16, 17, 18, 19, 20, 24, 25, 26, 27, 28) takes place in real time. Device for determining the position and for communication based on a UWB radio network (Ultra Wide Band), with a plurality of anchors (UWB transceivers with known position) (14, 15, 16, 17, 18, 19, 20), and at least one day (mobile UWB transceiver) (24, 25, 26, 27, 28), which is connected to the anchors (14, 15, 16, 17, 18, 19, 20) and with other tags (24, 25, 26, 27, 28), if available, forms the participants (14, 15, 16, 17, 18, 19, 20, 24, 25, 26, 27, 28) of the UWB radio network, the participants (14, 15, 16 , 17, 18, 19, 20, 24, 25, 26, 27, 28) are designed to carry out a position determination of the tags according to the TWR method (two way ranging) and at least partially at the same time to determine position data between the participants (14 , 15, 16, 17, 18, 19, 20, 24, 25, 26, 27, 28) with the participants (14, 15, 16, 17, 18, 19, 20, 24, 25, 26, 27, 28) are designed to switch between a position determination mode for position determination Immersion of tags (24, 25, 26, 27, 28) with blocking of the participants (14, 15, 16, 17, 18, 19, 20, 24, 25, 26, 27, 28) and a reception mode for receiving To carry out data of other participants (14, 15, 16, 17, 18, 19, 20, 24, 25, 26, 27, 28) with a certain switching frequency, the position determination mode having a fixed duration and the reception mode having a variable duration. Device after Claim 11 , in which all participants (14, 15, 16, 17, 18, 19, 20, 24, 25, 26, 27, 28) are designed to store data with a fixed data structure and the stored data between the participants (14 , 15, 16, 17, 18, 19, 20, 24, 25, 26, 27, 28) within the radio range. Device after Claim 11 or 12 , in which the participants (14, 15, 16, 17, 18, 19, 20, 24, 25, 26, 27, 28) are trained to measure between at least two participants (14, 15, 16, 17, 18, 19, 20, 24, 25, 26, 27, 28), preferably by signal delay measurement, data for communication to the other participants (14, 15, 16, 17, 18, 19, 20, 24, 25, 26 , 27, 28) to be transmitted within the radio range. Device after Claim 13 , in which the participants (14, 15, 16, 17, 18, 19, 20, 24, 25, 26, 27, 28) are designed to communicate at least the position data. Device after Claim 14 , in which the participants (14, 15, 16, 17, 18, 19, 20, 24, 25, 26, 27, 28) are trained to provide additional data regarding the speed and direction at which the tags (24, 25, 26, 27, 28) move to communicate. Device according to one of the Claims 11 to 15 , in which the participants (14, 15, 16, 17, 18, 19, 20, 24, 25, 26, 27, 28) are trained to measure between two participants (14, 15, 16, 17, 18 , 19, 20, 24, 25, 26, 27, 28) to block these participants (14, 15, 16, 17, 18, 19, 20, 24, 25, 26, 27, 28) from receiving further signals, however, the data sent by the participants involved in the runtime measurement (14, 15, 16, 17, 18, 19, 20, 24, 25, 26, 27, 28) from other participants (14, 15, 16, 17, 18, 19 , 20, 24, 25, 26, 27, 28) within the radio range. Device according to one of the Claims 11 to 16 , in which all participants (14, 15, 16, 17, 18, 19, 20, 24, 25, 26, 27, 28) are trained to store the stored data of the participants (14, 15, 16, 17, 18, 19, 20, 24, 25, 26, 27, 28) with all participants (14, 15, 16, 17, 18, 19, 20, 24, 25, 26, 27, 28) within the radio range.

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