NETWORK ARRANGEMENT AND METHOD FOR THE RADIO LOCATION OF OBJECTS WITHIN A CONFINED SPACE
20170245236 · 2017-08-24
Assignee
Inventors
- Matthias HELDMAIER (Stuttgart, DE)
- Andreas SCHUERZINGER (Schwaebisch Gmuend, DE)
- Daniel Schweizer (Filderstadt, DE)
Cpc classification
H04W64/00
ELECTRICITY
H04B7/2618
ELECTRICITY
International classification
H04W64/00
ELECTRICITY
H04H20/16
ELECTRICITY
Abstract
In a network arrangement for carrying out a location of locating objects that are arranged in a confined space and are able to be moved, the location being carried out by pulsed radio signals, wherein at least three communication-technically autarkic reference nodes that are spatially distributed and form a communication network are arranged in the confined space a communication protocol enables a location object that is arranged in the confined space to be localized by a trilateration carried out by a distance-based trilateration that is carried out by the at least three reference nodes.
Claims
1. A network arrangement for carrying out a location of locating objects that are arranged in a confined space (115) and are able to be moved, said location being carried out by means of pulsed radio signals, wherein at least three reference nodes (135-155) that are communication-technically autarkic, spatially distributed and form a communication network are arranged in the confined space (115), comprising a communication protocol, by means of which the management of at least one locating object (300-320) arranged in the confined space (115) is able to be carried out, wherein the at least one locating object (300-320) is able to located by means of a distance-based trilateration that is carried out by the at least three reference nodes (135-155).
2. The network arrangement according to claim 1, wherein the communication protocol depicts the respective topology of the communication network.
3. The network arrangement according to claim 1, wherein the confined space (115) is divided into at least two network segments, between which re-registrations of participants or locating objects are possible.
4. The network arrangement according to claim 1, wherein a location object (300-320) arranged in the confined space (115) is communication-technically assigned to one of the at least three reference nodes (135-155) at a given point in time.
5. The network arrangement according to claim 1, wherein, in addition to the at least three reference nodes (135-155), an administration node (100) is arranged in the confined space (115), by means of which the at least three reference nodes (135-155) and the arranged locating objects (300-320) as appropriate, are managed with communication technology.
6. The network arrangement according to claim 1, wherein “broadcast” signals are sent to participants of the communication network, by means of which signals changes in particular in the communication network are communicated.
7. The network arrangement according to claim 6, wherein changes in the communication network are registrations, deregistrations and re-registrations of participants.
8. The network arrangement according to claim 6, wherein the broadcast signals contain information about a global network topology and/or comprise the reference nodes present in the communication network and/or a clear identification code that is independent of the respective position of a participant in the communication network and/or a local code that is independent of the position of a participant in the communication network and/or further global network information.
9. The network arrangement according to claim 8, wherein the global network information comprises the position of a participant in the confined space (115) in a coordinate system suitable for localization.
10. The network arrangement according to claim 1, wherein the at least three reference nodes (135-155) are arranged (125) or formed to be communication technically linked to be linear, star-shaped or circular.
11. The network arrangement according to claim 10, wherein at least two linear chains (125, 130) of reference nodes (135-155, 160-180) are arranged in the confined space (115).
12. The network arrangement according to claim 1, comprising dynamic participant management, in which time slot plans and/or topology information about the communication network is dynamically provided to the participants.
13. A method for operating a network arrangement for locating at least one location object (300-320) by means of “trilateration” by pulsed radio signals, according to claim 1, wherein the at least one location object (300-320) is managed by means of a dynamic participant management, wherein time slot plans and/or topology information about the communication network is dynamically provided.
14. The method according to claim 13, wherein a dynamic time slot allocation is carried out by a suitable combination of both a time division multiple access method (TDMA) and by means of a code division multiple access method (CDMA).
15. The method according to claim 13, wherein global information about the global network topology is sent to the participant by means of a “broadcast” communication.
16. The method according to claim 15, wherein the signals transmitted by means of broadcast communication additionally comprise information about registrations, deregistrations and/or re-registrations.
17. The method according to claim 15, wherein the broadcast communication comprises an error-redundant forward broadcast of global information and of identification information of active participants.
18. The method according to claim 15, wherein registrations, deregistrations and/or re-registrations of participants are communicated to the administration nodes by means of a return broadcast.
19. The method according to claim 18, wherein the combination of forward broadcast and return broadcast ensures that a participant not uniquely reached by the forward broadcast is not excluded from participating in the communication and does not interrupt the communication with other participants.
20. The method according to claim 13, wherein a locating object newly registered in the localization network or segment listens to the broadcast communication in the network via a first communication channel in order to receive an overview of present reference nodes, and the location object communicates asynchronously with a reference node selected from the broadcast communication via a second communication channel, in order to cause the reception in the network.
21. The method according to claim 20, wherein the selected reference node allocates a preliminary code to the registered location object and provides global information about the network topology.
22. A computer program that is configured to carry out each step of a method according to claim 13.
23. A machine readable data storage device, on which a computer program according to claim 22 is stored.
Description
BRIEF DESCRIPTION OF THE DRAWINGS
[0034]
[0035]
[0036]
[0037]
[0038]
[0039]
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
[0040]
[0041] The network arrangement shown in
[0042] In the lower half of the depiction, a first daisy chain (C1) 125 branches off from the administration node 100 and in the upper half of the depiction, a second daisy chain (C2) 130 does so. Five reference nodes 135-155 are arranged along the first daisy chain 125 in this exemplary embodiment and five reference nodes 160-180 similarly do so in the second daisy chain 130. It should be noted that still no (real) location objects are shown in this depiction.
[0043] A localization measurement of participants carried out in the network shown in
[0044] In
[0045] This first exemplary embodiment relates to the network-sided discourse of new registrations by location objects. In this exemplary embodiment for dynamically managing participants in a UWB network for localization, it is assumed that a fundamentally functional localization network that is shown in
[0046] The number of five reference nodes per chain is only an example and can adopt any desired numerical value larger or smaller than 5, wherein the numerical value should preferably be >=3 in the two-dimensional or quasi-three dimensional localization of a locating object by means of trilateration. In a one dimensional localization or location of a locating object along a line, the numerical value has to be >=2. The two daisy chains can additionally also contain different numbers of reference nodes. However, a symmetrical construction is preferable from the point of view of resource efficiency and maximum measuring speed. The reference nodes from daisy chain C1 are subsequently shown by the numbers ‘11’ to ‘15’ and are contained in
[0047] For the purposes of simplifying the identification of the administration node, it bears the number ‘0’. In the exemplary embodiment, identifying reference nodes in the UWB network or segment takes place exclusively by means of UID and LID. It is assumed that said TDMA slot map shown as an example in
[0048] In this exemplary embodiment, a broadcast channel is labelled “B” and channels that are used for measuring, are labelled “M1” to “M5” according to
[0049] In this exemplary embodiment, the TDMA slot map consists of 32 slots 400 and is depicted in the table shown in
[0050] In a first slot not shown in
[0051] If possible, the four location objects ‘o1’ 300, ‘o2’ 305, ‘o3’ 310 and ‘o4’ 315 shown in
[0052] After the forward broadcast signal has reached the respective ends of the daisy chains, sending a return broadcast signal 335 shown in
[0053] In the exemplary embodiment, said new registrations in the return broadcast are propagated and accumulated by their UID and assigned LID along the daisy chain from their end. Corresponding to the exemplary embodiment shown in
[0054] The described return broadcast process is uniform for every reference node along the daisy chain C1. The same method is also applied separately for the return broadcast in daisy chain C2. In the present exemplary embodiment, the daisy chains do not interact with each other during the broadcast, whereby the end point of the two return broadcast signal tracks is the administration node of the respective network or segment. With two daisy chains, a maximum number of ten new registrations per “slot map” cycle can thus take place, wherein collisions can effectively be avoided from the start. By using a longer slot map, an interaction of the two daisy chains can take place via the return broadcast, if, in the meantime, no measuring communication takes place, similar to the situation with the forward broadcast. Thus, a higher redundancy can be achieved.
[0055] After receiving the return broadcast, the administration node registers the new participant into the “chain occupation” data field and prepares a forward broadcast packet for the next “slot map” run, by the new registrations that have taken place in the meantime being communicated to the receiving reference nodes or participants.
[0056] The described process duration presents a possible implementation of the process of managing participants. Other manifestations of the method are also possible.
In this way, in an extension of the procedure, diagnosis information about the registered participants and reference nodes can additionally be accumulated and communicated in the return broadcast, in order to simultaneously obtain a dynamic entire overview of the network and to prevent it coming to failures or interruptions. The administration node can communicate this diagnosis information, in particular also the information about new registrations to a central server 110 via an input 105 shown in
[0057] According to the preceding description of the network-side processing of a new participant registering (i.e. substantially by the reference nodes) on a UWB network related here for localization, an exemplary embodiment of the process course for registering a locating object is subsequently described.
[0058] In this exemplary embodiment, the described, special arrangement of the TDMA process and the described channel structure are particularly advantageous. The “TDMA slot map” is arranged here in such a way that localization measurements only ever take place in the channels M1-M5 shown in
[0059] In the present return broadcast signal, a special method can be applied, in which e.g. only ever one of two direct successors in the daisy chain is unable to receive any registration messages. This can additionally be dynamically adapted via the network diagnosis in order to dynamically compensate failures by reference nodes. In this way, even a new registration of a participant can thus take place, despite a regularly running localization measuring operation and return broadcasts.
[0060] If a location object should be newly received or registered in the localization network or a network segment, for example the location object ‘o5’ 320 shown in
[0061] The course of the registration process is depicted in detail in
[0062] If the communication cannot thus be established for a long time, the locating object contacts a different reference node. The registration packet thus consists of a request command to be received on the network, the UID of the node and some further information about the locating object. In particular, it is thus also communicated which configuration state, if present, from its most recent participation in the location communication as to the locating object is in.
[0063] Every registration attempt is initially confirmed by the respectively contacted reference node with information 650 which specifies whether the registering participant may or may not register at all. In this way, a participant can be rejected if an empirically predetermined, maximally permissible participant number in the network segment has been reached, if the applicant has been identified as a reference node because of its UID or if the network is in an operation state that is not suitable for localization. The thus respectively contacted reference node has a complete overview of the topology of the network at any time because of the broadcast information running in the segment, said information forming the scope of the UWB communication. In this way, the reference node can decide, by means of the transmitted information of the participant, what information the participant needs to receive in the UWB network, to be able to carry out the registration process in a resource-efficient manner. The information that is thus provided to the applicant in the subsequent communication thus comprises said “almanac” list. Additionally, the applicant receives a preliminary LID and relevant information about the selected coordinate system (coordinate transformation, rotation) as a communication.
[0064] In this exemplary embodiment, the communication of said broadcast information takes place in the form of several telegram pages, exemplarily depicted via the packets 655, 665, 675 and 685, which are each able to be identified via their page number and the UID of the addressed applicant (or of the registering participant) in connection with a data acquisition command. A telegram page can, in the chosen example, thus contain 124 bytes of information, in order to complete the respective communication process before a next slot in the slot map begins. The applicant confirms 660, 670, 680 and 690 the received information by stating its UID and the receiving side. The correspondingly suitable page size thus depends on the chosen length of the TDMA slots and, in the chosen manifestation of the hardware used, can reach up to 1000 bytes. However, any other page lengths are also conceivable. Typically, the amount of information to be transferred is around 20 to 30 page, in some cases more. The participant now registered generates an individual slot map after completing 695 the registration communication, and indeed by omitting the own measuring slots, and then initially listens to the broadcast channel B of its network segment 697, in order to directly hear possible subsequent further network changes. In the “return broadcast” (not shown here) of the current communication in the present segment or, if a new slot map course has already started, in the forward broadcast, the newly registered participant can monitor the disclosure of its re-registration (or registration in the new segment).
[0065] In order to prevent possible collisions with other registration processes in the described communication of the network topology, said processes being able to run in parallel on further reference nodes of the same daisy chain, a demand can additionally be made by the applicant before sending data.
[0066] Subsequently, a second exemplary embodiment or usage scenario shown in
[0067] In this usage scenario, the previously described process course can be correspondingly used in every segment of the network. The channels for measuring M1-M5 described by means of
[0068] In order to prevent crosstalk of (UWB) communication channels between the different segments depicted in
[0069] In the location network schematically depicted on the right side of
[0070] In the present usage scenario, the method already described above for communication, producing a TDMA slot map, for communication along the daisy chain and the existing nodes can be correspondingly used in a functional segment. Addressing or identifying participants in a segment further takes place only via their LID. Alternatively, identifying the participants can also take place via a combination of LID and SID in the segment-internal communication. The SID in the present exemplary embodiment has a length of 1 Byte in order to guarantee the most efficient communication at simultaneously high numbers of participants. Thus 256 subnets (or segments) are conceivable in one localization network. Said parameters form only one exemplary information set and further information about the complete description of the network topology may be necessary.
[0071] However, the described method for a participant (newly) registering is presently complemented by a block which represents the search for the network segment. Said broadcast channel B is always clearly able to be identified via the above depicted manner of channel bundling. It is unknown to a location object itself as to which SID the next available segment of the localization network has. If a location object is newly registered, the location object initially identifies the next available network segment. This happens in turn by listening to a broadcast channel, by which status updates communicated in the segment are sent. The location object now changes in a coincidental or deterministic manner, by all or one part of the possible channel bundle in the respective broadcast channel. This process can take place until a signal is incidentally detected on a broadcast channel. A more reliable manifestation of the invention partially or completely changes as a result of the remaining broadcast channels and tries to record a status update of a different network segment. The process duration already described for registering is then carried out subsequently in one network segment, for which the best available signal to noise ratio has been achieved.
[0072] Apart from the allocation of an LID given in the above description, when registering, the reference node in which the registration process is taking place additionally communicates the SID of the network segment, in which the location object is currently trying to register, to the location object.
[0073] By creating different network segments in which the communication takes place in independent code channels, a size technical scale of location networks can be achieved. This scalability allows for both the distribution of location objects across the different segments and the bundling of measurements on reference nodes available in one segment without dramatic influence on the surfaces—and thus of the number of necessary reference nodes—and of the participant number at the measuring interval.
[0074] The segmenting of a localization network certainly requires the creation of the possibility of participants re-registering between different network or radio segments, in order to guarantee free movement of location objects across the entire location network. This transfer of location objects between network segments is described below.
[0075] To support such a re-registration process, the result of the location of an object can thus be used, and indeed together with the information that the location object has obtained during its initial registration in a segment or via broadcast messages in the measuring duration. Thus, the location object can decide, based on its position (and e.g. additionally based on its movement direction) and the present almanac data, when it has reached a segment in the location network that is better suited to location. One criterion for the suitability of a location segment can for example be the proximity to the reference nodes, the exactness of the location results that is theoretically able to be achieved, the signal strength of the received communication or a combination of such criteria. Other criteria, which are based on a map of the space in which the location object moves, or are met by adaptive/neuronal algorithms, are thus able to be used. If the locating object decides to change into a different segment, then both the SID of the target segment and the positions of the reference nodes of this segment are known to it from the almanac list.
[0076] The exact process course of this communication is exemplarily depicted in
[0077] If the version of the almanac list, the coordinate transformation or the logical spaces have to be changed in the current broadcast, the re-registering participant receives this change communicated by the reference node. Furthermore, the re-registering participant receives a new preliminary LID and information about the allocation of reference nodes of the segment with regards to the respective daisy chains and their sequence within their respective daisy chain. In total, there is thus a very small amount of information that can be transferred in a data page. In this way, the re-registering participant can immediately generate 720 a preliminary slot map and, on receiving its acceptance in the segment, can immediately change 725 to the TDMA mode.
[0078] The participant re-registered in such a way initially further listens to the broadcast channel B of its new network segment 730 in order to directly listen to any network changes, however omits its provided time slots for the subsequent TDMA measuring operation 735. In the return broadcast (not shown here) of the current communication in the present segment or, if a new slot map process has already started, in the forward broadcast, the re-registered participant can recognize the disclosure of its re-registration (or registration in the new segment) and from then on participate in the next slot map run in the regular measuring operation. Before re-registering in the new network segment, a deregistration can additionally take place in the previous network segment in order to achieve as efficient a communication as possible between the participants found there, even in the previous network segment.