US20110188389A1 - Wireless Localisation System - Google Patents

Wireless Localisation System Download PDF

Info

Publication number
US20110188389A1
US20110188389A1 US13/002,640 US200913002640A US2011188389A1 US 20110188389 A1 US20110188389 A1 US 20110188389A1 US 200913002640 A US200913002640 A US 200913002640A US 2011188389 A1 US2011188389 A1 US 2011188389A1
Authority
US
United States
Prior art keywords
nodes
location
anchor
node
range
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Abandoned
Application number
US13/002,640
Other languages
English (en)
Inventor
Mark Hedley
David Eric Humphrey
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Commonwealth Scientific and Industrial Research Organization CSIRO
Original Assignee
Commonwealth Scientific and Industrial Research Organization CSIRO
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Priority claimed from AU2008903441A external-priority patent/AU2008903441A0/en
Application filed by Commonwealth Scientific and Industrial Research Organization CSIRO filed Critical Commonwealth Scientific and Industrial Research Organization CSIRO
Assigned to COMMONWEALTH SCIENTIFIC AND INDUSTRIAL RESEARCH ORGANISATION reassignment COMMONWEALTH SCIENTIFIC AND INDUSTRIAL RESEARCH ORGANISATION ASSIGNMENT OF ASSIGNORS INTEREST (SEE DOCUMENT FOR DETAILS). Assignors: HEDLEY, MARK, HUMPHREY, DAVID ERIC
Publication of US20110188389A1 publication Critical patent/US20110188389A1/en
Abandoned legal-status Critical Current

Links

Images

Classifications

    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01S—RADIO DIRECTION-FINDING; RADIO NAVIGATION; DETERMINING DISTANCE OR VELOCITY BY USE OF RADIO WAVES; LOCATING OR PRESENCE-DETECTING BY USE OF THE REFLECTION OR RERADIATION OF RADIO WAVES; ANALOGOUS ARRANGEMENTS USING OTHER WAVES
    • G01S5/00—Position-fixing by co-ordinating two or more direction or position line determinations; Position-fixing by co-ordinating two or more distance determinations
    • G01S5/02—Position-fixing by co-ordinating two or more direction or position line determinations; Position-fixing by co-ordinating two or more distance determinations using radio waves
    • G01S5/14—Determining absolute distances from a plurality of spaced points of known location
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01S—RADIO DIRECTION-FINDING; RADIO NAVIGATION; DETERMINING DISTANCE OR VELOCITY BY USE OF RADIO WAVES; LOCATING OR PRESENCE-DETECTING BY USE OF THE REFLECTION OR RERADIATION OF RADIO WAVES; ANALOGOUS ARRANGEMENTS USING OTHER WAVES
    • G01S13/00—Systems using the reflection or reradiation of radio waves, e.g. radar systems; Analogous systems using reflection or reradiation of waves whose nature or wavelength is irrelevant or unspecified
    • G01S13/87—Combinations of radar systems, e.g. primary radar and secondary radar
    • G01S13/876—Combination of several spaced transponders or reflectors of known location for determining the position of a receiver
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01S—RADIO DIRECTION-FINDING; RADIO NAVIGATION; DETERMINING DISTANCE OR VELOCITY BY USE OF RADIO WAVES; LOCATING OR PRESENCE-DETECTING BY USE OF THE REFLECTION OR RERADIATION OF RADIO WAVES; ANALOGOUS ARRANGEMENTS USING OTHER WAVES
    • G01S13/00—Systems using the reflection or reradiation of radio waves, e.g. radar systems; Analogous systems using reflection or reradiation of waves whose nature or wavelength is irrelevant or unspecified
    • G01S13/87—Combinations of radar systems, e.g. primary radar and secondary radar
    • G01S13/878—Combination of several spaced transmitters or receivers of known location for determining the position of a transponder or a reflector
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01S—RADIO DIRECTION-FINDING; RADIO NAVIGATION; DETERMINING DISTANCE OR VELOCITY BY USE OF RADIO WAVES; LOCATING OR PRESENCE-DETECTING BY USE OF THE REFLECTION OR RERADIATION OF RADIO WAVES; ANALOGOUS ARRANGEMENTS USING OTHER WAVES
    • G01S5/00—Position-fixing by co-ordinating two or more direction or position line determinations; Position-fixing by co-ordinating two or more distance determinations
    • G01S5/01—Determining conditions which influence positioning, e.g. radio environment, state of motion or energy consumption
    • G01S5/017—Detecting state or type of motion
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01S—RADIO DIRECTION-FINDING; RADIO NAVIGATION; DETERMINING DISTANCE OR VELOCITY BY USE OF RADIO WAVES; LOCATING OR PRESENCE-DETECTING BY USE OF THE REFLECTION OR RERADIATION OF RADIO WAVES; ANALOGOUS ARRANGEMENTS USING OTHER WAVES
    • G01S5/00—Position-fixing by co-ordinating two or more direction or position line determinations; Position-fixing by co-ordinating two or more distance determinations
    • G01S5/02—Position-fixing by co-ordinating two or more direction or position line determinations; Position-fixing by co-ordinating two or more distance determinations using radio waves
    • G01S5/0205—Details
    • G01S5/0218—Multipath in signal reception
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01S—RADIO DIRECTION-FINDING; RADIO NAVIGATION; DETERMINING DISTANCE OR VELOCITY BY USE OF RADIO WAVES; LOCATING OR PRESENCE-DETECTING BY USE OF THE REFLECTION OR RERADIATION OF RADIO WAVES; ANALOGOUS ARRANGEMENTS USING OTHER WAVES
    • G01S5/00—Position-fixing by co-ordinating two or more direction or position line determinations; Position-fixing by co-ordinating two or more distance determinations
    • G01S5/02—Position-fixing by co-ordinating two or more direction or position line determinations; Position-fixing by co-ordinating two or more distance determinations using radio waves
    • G01S5/0205—Details
    • G01S5/0226—Transmitters
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01S—RADIO DIRECTION-FINDING; RADIO NAVIGATION; DETERMINING DISTANCE OR VELOCITY BY USE OF RADIO WAVES; LOCATING OR PRESENCE-DETECTING BY USE OF THE REFLECTION OR RERADIATION OF RADIO WAVES; ANALOGOUS ARRANGEMENTS USING OTHER WAVES
    • G01S5/00—Position-fixing by co-ordinating two or more direction or position line determinations; Position-fixing by co-ordinating two or more distance determinations
    • G01S5/02—Position-fixing by co-ordinating two or more direction or position line determinations; Position-fixing by co-ordinating two or more distance determinations using radio waves
    • G01S5/0284—Relative positioning
    • G01S5/0289—Relative positioning of multiple transceivers, e.g. in ad hoc networks

Definitions

  • the present invention relates generally to wireless localisation, and in particular to tracking objects using radio signals based on measurement of the time-of-arrival.
  • a wireless localisation system refers to any system that uses transmission of electromagnetic signals (e.g. radio frequency or microwave) to localise (estimate the location of) an object, in two dimensions or three dimensions.
  • Mobile objects can be localised and/or tracked by attaching a signal-enabled tag to the object and using a set of fixed ‘anchor’ nodes in the area to be monitored.
  • Inaccuracies in the location estimates arise due to (1) the properties of the radio propagation environment (e.g. multipath reflections and diffraction) and (2) limitations in the system hardware (e.g. lack of time/frequency synchronisation and propagation delays in hardware that are time varying). The latter issues are particularly severe in applications where the anchor nodes have wireless connections and must consist of low-cost hardware.
  • RSS received signal strength
  • TOA time-of-arrival
  • AOA angle-of-arrival
  • RSS techniques require expensive hardware to determine the direction of arrival, and may perform poorly in multipath environments where reflections arrive from many directions.
  • a common TOA-based technique is satellite navigation (e.g. GPS); however, this is not possible in indoor environments or even in outdoor environments where the accuracy is significantly degraded by multipath signals (e.g. urban canyons).
  • the most common TOA-based localisation system uses receiving anchor nodes that are hard-wired (cabled) to the processing hardware (e.g. U.S. Pat. No. 6,831,603). This greatly simplifies the system as a common clock can be shared, eliminating the problem of frequency and time synchronisation. In some situations, such as where rapid installation is required or the region between receiving nodes is inaccessible or inappropriate for cable installation, cabled connections between anchor nodes are impractical.
  • the frequency and time synchronisation problem is often handled by using two way (also known as round trip) localisation, and usually also by the use of a reference node (e.g. US Patent 2003/0092448).
  • This approach transmits a signal from one node to another, followed immediately by a return signal.
  • the time between receiving the forward message and transmitting the reverse message is often assumed to be constant, which is not the case in many practical systems.
  • the location of the mobile nodes is estimated in a process known as ‘multilateration’.
  • the most common technique uses a minimum mean squared error (MMSE) approach. With this technique, ‘bad’ range data can severely affect the estimated locations of the mobile nodes.
  • MMSE minimum mean squared error
  • Another technique with a different assumption on the error distribution is based on Projections onto Convex Sets (POCS); however, conventional POCS algorithms do not handle well the case where there is a large intersection region. As with MMSE, the POCS approach is susceptible to bad data due to effects such as multipath reflections, radio interference and fading phenomena.
  • a method of computing a round trip delay between a pair of nodes comprising:
  • a method of estimating the location of a mobile object using a plurality of ranges between a node associated with said object and respective anchor nodes comprising:
  • a method of estimating the location of a mobile object using a plurality of ranges between a node associated with said object and respective anchor nodes comprising:
  • each said constraint set being a circle centred on one said anchor node with radius equal to the corresponding range, to obtain an end point;
  • said end point is said estimated location of said mobile object.
  • a method of time synchronising a plurality of anchor nodes comprising:
  • a method of estimating the location of a mobile object using a plurality of anchor nodes comprising:
  • a system for estimating the location of one or more objects comprising:
  • beacons data capability to send measured times-of-arrival of said beacons, and transmit times of said beacons, to a location server adapted to compute the location of said objects.
  • a system for estimating the location of an object comprising:
  • a plurality of anchor nodes adapted to communicate wirelessly with each other by either transmitting or receiving beacons;
  • a mobile node coincident with said object the mobile node being adapted to communicate wirelessly with said anchor nodes by either transmitting or receiving said beacons;
  • a localisation server adapted to:
  • the disclosed arrangements include a system for wireless localisation and tracking, and methods that can be used in the disclosed system or other systems.
  • the disclosed arrangements estimate object location using multilateration based on measured time-of-arrival (TOA) of radio signals.
  • TOA time-of-arrival
  • the disclosed arrangements enable more robust processing and hence more accurate location estimation compared to existing systems and methods in the face of bad data due to typical sources of error such as TOA measurement errors (e.g. due to multipath interference or propagation effects), unsynchronised clocks in nodes, time varying propagation delay through the node electronics, and object motion.
  • the disclosed system using only low-cost consumer electronic components, is capable of covering large areas (i.e. is not limited to direct radio communication links between all nodes) and is capable of rapid deployment as cabling is not required between any nodes.
  • FIG. 1 shows an example of a tracking system within which the disclosed arrangements may be practised
  • FIG. 2 is a flow diagram illustrating a general method of localisation according to the preferred embodiment
  • FIG. 3 is a schematic block diagram of a general purpose computer upon which disclosed methods can be practised
  • FIG. 4 a is an illustration of a beaconing node according to the preferred embodiment
  • FIG. 4 b is an illustration of the format of a beacon according to the preferred embodiment
  • FIG. 5 is an illustration of an exemplary TDMA beacon schedule
  • FIG. 6 is an illustration of a location server according to the preferred embodiment
  • FIG. 7 is a flow diagram illustrating a method of estimating the location of mobile nodes according to the preferred embodiment
  • FIG. 8 a illustrates a sequence of beacon transmissions
  • FIG. 8 b illustrates the motion of a mobile node during the beacon transmissions of FIG. 8 a
  • FIG. 9 illustrates the estimation of the location of a node according to the POCS algorithm in an example scenario.
  • Appendix A contains pseudocode for a robust MMSE algorithm for estimating the location of a mobile node.
  • FIG. 1 shows an example of a tracking system 100 within which the disclosed arrangements may be practised, comprising one soccer player 110 , several fixed anchor nodes, e.g. 120 , surrounding the field, and a location server 130 .
  • a tracking system 100 within which the disclosed arrangements may be practised, comprising one soccer player 110 , several fixed anchor nodes, e.g. 120 , surrounding the field, and a location server 130 .
  • the anchor nodes 120 are wirelessly connected to the location server to simplify deployment (although where convenient a cable or fibre connection can be used and will usually improve system performance).
  • the disclosed tracking system comprises:
  • the wireless data communication is preferably performed using direct sequence spread spectrum signalling; however, it could be equally well performed using any radio communication protocol (e.g. the 802.11 family of standards).
  • FIG. 2 is a flow diagram illustrating a general method 200 of localisation according to the preferred embodiment.
  • step 210 certain nodes called beaconing nodes periodically transmit radio signals called beacons that are received by some other nodes called TOA reception nodes that are able to measure the TOA of the beacon.
  • the beacons contain a localisation signal designed for accurate measurement of TOA and an optional data payload. While the localisation signal could be a data symbol, better results are obtained using a specially designed localisation signal.
  • the mobile nodes may be beaconing nodes and/or TOA reception nodes, and likewise the anchor nodes may be beaconing nodes and/or TOA reception nodes. For example:
  • TDMA time division multiple access
  • CDMA code division multiple access
  • FDMA frequency division multiple access
  • the TOA reception nodes measure the TOA for each received beacon, and at step 230 the TOA reception nodes send the TOA data to the location server (preferably via the data payload in their own beacons, or alternatively via other means such as cable, particularly if a TOA reception node is not also a beaconing node).
  • the transmit time of beacons is also required, and beaconing nodes can send this to the location server as a data field in the beacon or by other means. There may be other data such as that related to system operation, for protocols, or from sensors, that is also sent to the location server.
  • the location server at step 240 applies a localisation algorithm to the received data to estimate the location of the mobile nodes.
  • a beaconing node 400 according to the preferred embodiment is illustrated in FIG. 4 a .
  • the beaconing node 400 has digital electronics 430 to generate a beacon and a module 420 to convert the beacon to analog form for radio transmission using a radio transceiver 410 in step 210 of the method 200 .
  • the beaconing node 400 also receives data at least to allow synchronisation of TDMA slots, so the data flow in the beaconing node 400 is bidirectional.
  • the format of a beacon 450 comprising a header 460 , a data field (payload) 470 , and a TOA localisation signal 480 , is illustrated in FIG. 4 b .
  • the TOA localisation signal 480 is specially designed to maximise the accuracy with which the TOA of the signal is measured by a TOA reception node.
  • a separate TOA localisation signal 480 is not used and instead a known signal pattern in the header 460 is used to measure the TOA.
  • the data field 470 is optional.
  • the beacons 450 are scheduled to minimise self-interference and hence maximise localisation accuracy.
  • the update rate of a mobile node's location estimate is limited to the rate at which that node transmits beacons.
  • Previous schemes for round trip localisation involved a beacon being sent to a node and a reply being immediately generated. For all nodes involved in the measurement (for time synchronisation, propagation delay measurement or mobile node localisation), there is a beacon sent from each node to each of the other nodes. By contrast, according to the disclosed arrangements for round trip localisation, each beaconing node transmits just one beacon per measurement.
  • the advantage is that the number of localisation signal transmissions is greatly reduced, which can reduce power consumption and/or increase the number of nodes the system can support. Under the disclosed arrangements, there can be large and variable time intervals between the transmissions of beacons between pairs of nodes. As described in detail below, this time interval is measured and adequately corrected for.
  • the preferred TDMA scheme 500 is illustrated in FIG. 5 .
  • Time is divided into slots, e.g. 510 , with a beacon being sent in each slot by the node corresponding to the slot label (M 1 is mobile node 1 , A 1 is anchor node 1 , etc).
  • a slot can be used by plural nodes, provided the minimum radio link hop count between the nodes using the same slot is greater than two (hence not all nodes have the same schedule).
  • the slot size will generally be as small as possible, preferably adjustable between 1 ms and 10 ms.
  • the update rate of the beacons is determined by the localisation algorithm category.
  • all nodes should transmit at least at the minimum localisation update rate.
  • the mobile nodes For mobile transmit localisation, the mobile nodes should transmit at the minimum localisation update rate; however the anchor nodes should transmit at the required rate to maintain time synchronisation, which is in turn dependent upon the stability of the local oscillators in each node.
  • the slots are grouped in superframes, e.g. 520 , as this simplifies the TDMA scheme; however, it is not necessary.
  • the schedule of each superframe is generally the same, except for dynamic behaviour in the network (e.g. mobile nodes moving in and out of range).
  • the scheduling of beacons into slots can be static or dynamic.
  • Static allocation in which the schedule is known in advance by all nodes, is simpler but does not allow slot reuse in multi-hop networks.
  • Dynamic allocation entails additional communication overhead, either mutually among the nodes according to a distributed algorithm, or between a scheduling controller (e.g. the location server) and the nodes.
  • Coarse time synchronisation is required between all nodes for the TDMA scheme; however, this only needs to be within a fraction of the slot duration (e.g. one percent, or 10 ⁇ s for 1 ms slots), which is readily achieved in nodes designed to measure TOA with high accuracy (typically better than 1 ns).
  • the synchronisation time reference is provided by one of the nodes either by fixed allocation or selection by the nodes themselves (the latter alternative providing robustness should the time reference node fail). This time synchronisation is too coarse to be of any assistance for localisation.
  • TOA reception nodes are adapted to receive a beacon, convert it to digital form, and process it to measure with high resolution the TOA of the beacon (step 220 of the method 200 ).
  • a TOA reception node also preferably uses wireless communication to transmit the TOA values to the location server (step 230 of the method 200 ).
  • the TOA data is sent to the location server in the data field 470 of the beacon format 450 shown in FIG. 4 b .
  • 400 in FIG. 4 a equally well represents a TOA reception node according to the preferred embodiment.
  • the measurement of the TOA (step 220 ) is preferably carried out by a TOA reception node according to the method described in the PCT patent application no. PCT/AU2009/000647. However, any technique for the measurement of TOA may alternatively be used.
  • a location server 600 according to the preferred embodiment is illustrated in FIG. 6 .
  • the location server 600 comprises an analog radio receiver 610 , an analog to digital converter 620 , and digital processing electronics 630 .
  • the location server 600 processes the received data from the TOA reception nodes and uses this information to estimate the location of mobile nodes (step 240 ).
  • the location server 600 may also perform other functions such as performing and/or reporting system diagnostics and recording and formatting sensor data from the system.
  • the digital processing electronics 630 on which the location estimation and any other processing are implemented, are therefore more powerful than the digital processing electronics 430 of either an anchor node or a beacon node.
  • the digital processing electronics 630 comprises the digital processing electronics 430 of an anchor node connected via a USB interface to a general purpose computer system 300 such as that shown in FIG. 3 , wherein the processing of step 240 may be implemented as software, such as one or more application programs executable within the computer system 300 .
  • the processing of step 240 is effected by instructions in the software that are carried out within the computer system 300 .
  • the instructions may be formed as one or more code modules, each for performing one or more particular tasks.
  • the software may also be divided into two separate parts, in which a first part and the corresponding code modules performs the location estimation processing and a second part and the corresponding code modules manage an interface between the first part and other systems.
  • the software may be stored in a computer readable medium, including the storage devices described below, for example.
  • the software is loaded into the computer system 300 from the computer readable medium, and then executed by the computer system 300 .
  • a computer readable medium having such software or computer program recorded on it is a computer program product.
  • the use of the computer program product in the computer system 300 preferably effects an advantageous apparatus for estimating the location of mobile nodes.
  • the computer system 300 is formed by a computer module 301 , input devices such as a keyboard 302 and a mouse pointer device 303 , and output devices including a printer 315 , a display device 314 and loudspeakers 317 .
  • An external Modulator-Demodulator (Modem) transceiver device 316 may be used by the computer module 301 for communicating to and from a communications network 320 via a connection 321 .
  • the computer module 301 typically includes at least one processor unit 305 , and a memory unit 306 for example formed from semiconductor random access memory (RAM) and read only memory (ROM).
  • the module 301 also includes a number of input/output (I/O) interfaces including an audio-video interface 307 that couples to the video display 314 and loudspeakers 317 , an I/O interface 313 for the keyboard 302 and mouse 303 and optionally a joystick (not illustrated), and an interface 308 for the external modem 316 and printer 315 .
  • the modem 316 may be incorporated within the computer module 301 , for example within the interface 308 .
  • the computer module 301 also has a local network interface 311 which, via a connection 323 , permits coupling of the computer system 300 to a local computer network 322 , known as a Local Area Network (LAN).
  • LAN Local Area Network
  • the local network 322 may also couple to the wide network 320 via a connection 324 , which would typically include a so-called “firewall” device or similar functionality.
  • the interface 311 may be formed by an EthernetTM circuit card, a wireless BluetoothTM or an IEEE 802.11 wireless arrangement.
  • the interfaces 308 and 313 may afford both serial and parallel connectivity, the former typically being implemented according to the Universal Serial Bus (USB) standards and having corresponding USB connectors (not illustrated).
  • Storage devices 309 are provided and typically include a hard disk drive (HDD) 310 .
  • HDD hard disk drive
  • Other devices such as a floppy disk drive, a flash memory drive, and a magnetic tape drive (not illustrated) may also be used.
  • An optical disk drive 312 is typically provided to act as a non-volatile source of data.
  • Portable memory devices, such optical disks (eg: CD-ROM, DVD), USB-RAM, and floppy disks for example may then be used as appropriate sources of data to the system 300 .
  • the components 305 , to 313 of the computer module 301 typically communicate via an interconnected bus 304 and in a manner which results in a conventional mode of operation of the computer system 300 known to those in the relevant art.
  • Examples of computers on which the described arrangements can be practised include IBM-PC's and compatibles, Sun Sparcstations, Apple MacTM or like computer systems evolved therefrom.
  • the application programs discussed above are resident on the hard disk drive 310 and read and controlled in execution by the processor 305 . Intermediate storage of such programs and any data fetched from the networks 320 and 322 may be accomplished using the semiconductor memory 306 , possibly in concert with the hard disk drive 310 . In some instances, the application programs may be supplied to the user encoded on one or more CD-ROM and read via the corresponding drive 312 , or alternatively may be read by the user from the networks 320 or 322 . Still further, the software can also be loaded into the computer system 300 from other computer readable media. Computer readable media refers to any storage medium that participates in providing instructions and/or data to the computer system 300 for execution and/or processing.
  • Examples of such media include floppy disks, magnetic tape, CD-ROM, a hard disk drive, a ROM or integrated circuit, a magneto-optical disk, or a computer readable card such as a PCMCIA card and the like, whether or not such devices are internal or external of the computer module 301 .
  • Examples of computer readable transmission media that may also participate in the provision of instructions and/or data include radio or infra-red transmission channels as well as a network connection to another computer or networked device, and the Internet or Intranets including e-mail transmissions and information recorded on Websites and the like.
  • the second part of the application programs and the corresponding code modules mentioned above may be executed to implement one or more graphical user interfaces (GUIs) to be rendered or otherwise represented upon the display 314 .
  • GUIs graphical user interfaces
  • a user of the computer system 300 and the application may manipulate the interface to provide controlling commands and/or input to the applications associated with the GUI(s).
  • the digital processing electronics 630 may alternatively be dedicated hardware such as one or more integrated circuits performing the functions or sub functions of the step 240 .
  • Such dedicated hardware may include graphic processors, digital signal processors, or one or more microprocessors and associated memories with data interfaces (e.g. WLAN or USB or serial interface) but no user interface devices.
  • the digital processing electronics 430 of the beaconing/TOA reception node 400 is also preferably dedicated hardware of this kind.
  • the location server 600 can utilise round trip or mobile transmit localisation, depending on the specifics of the application.
  • An advantage of mobile transmit localisation for tracking objects moving at high velocity is that this approach only uses a single beacon, and is thus only affected by motion for the duration of the beacon (preferably about 0.5 ms).
  • the estimation requires all beacons to and from the mobile node in a superframe, which may be extended over a significant period of time (up to 100 ms where 20 slots of 5 ms are used). It is described below how the effect of constant velocity motion can be corrected for under round trip localisation.
  • a tradeoff in the choice of the localisation algorithm is that round trip localisation results are degraded by non-constant velocity motion over the superframe, while mobile transmit localisation results are degraded by errors in anchor node time synchronisation.
  • the location server 600 can implement multiple localisation algorithms simultaneously, as in the following exemplary scenarios:
  • FIG. 7 is a flow diagram illustrating a method 700 according to the preferred embodiment of estimating the location of mobile nodes.
  • the main decisions in the method 700 are whether the propagation delay of the anchor nodes is known from prior calibration, and whether mobile transmit or round trip localisation is used.
  • round trip localisation with known anchor node propagation delay values there is the further choice of using a MMSE-based or POCS-based localisation algorithm. These choices may be made dynamically, each time the method 700 is executed, or in advance, in which case only the relevant portions of the method 700 need be implemented.
  • the steps of the method 700 are mostly carried out by the location server 600 , except for TOA measurement steps 715 , 752 , 735 , 770 , and 775 which are done by beaconing nodes and TOA reception nodes 400 , and the results sent to the location server 600 , as shown by the method 200 .
  • the method 700 starts at step 710 where it is determined whether the propagation delay of the anchor nodes is known from prior calibration. If not, the method 700 proceeds to step 715 at which the TOA at each anchor node from all other anchor nodes is measured. In step 720 the corrected round trip delay between each pair of anchor nodes is computed as described below. Step 725 follows, at which the propagation delay at each anchor node is computed as described below.
  • step 730 it is checked at step 730 whether round trip localisation is to be used. If not, step 735 measures the TOA at each anchor node from each mobile node.
  • Step 740 follows, at which the anchor nodes are time synchronised as described below.
  • the Pseudo-Range (see below) between all anchor and mobile nodes is then computed at step 745 as described below, after which at step 750 a robust MMSE-based Time Difference of Arrival (TDOA) algorithm described below is used to estimate the location of each mobile node.
  • TDOA Time Difference of Arrival
  • step 752 measures the TOA at each anchor node from each mobile node, and vice versa. Then at step 754 , the method 700 computes the Corrected Round Trip Delay between each anchor node and each mobile node as described below. Step 756 follows, at which the Pseudo-Range between all anchor and mobile nodes is computed as described below. Finally at step 758 a robust MMSE-based TOA algorithm, described below, is used to estimate the location of each mobile node.
  • step 756 computes range rather than pseudo-range, and step 758 would use either a robust MMSE-based or a POCS-based TOA algorithm, to be described below, to estimate the location of each mobile node from the computed ranges.
  • the propagation delay at the mobile nodes is unlikely to be known as the propagation delay of the anchor nodes was initially unknown.
  • the method 700 then concludes at step 795 .
  • step 765 checks whether round trip localisation is to be used. If not, step 770 measures the TOA at each anchor node from all other anchor nodes and all mobile nodes. The method 700 then continues from step 740 as described above.
  • step 775 measures the TOA at each anchor node from each mobile node, and vice versa. Then at step 780 , the method 700 computes the Corrected Round Trip Delay between each anchor node and each mobile node as in step 754 . Step 785 follows, at which the range between all anchor and mobile nodes is computed (assuming the propagation delay at the mobile nodes is known, which is likely since the propagation delay at the anchor nodes is known). Finally at step 790 the robust MMSE- or POCS-based TOA algorithm is used to estimate the location of each mobile node, as in step 758 .
  • step 785 computes Pseudo-Range rather than range, and step 790 can only use the robust MMSE-based TOA algorithm, as in step 758 .
  • the method 700 then concludes at step 795 .
  • the two nodes are labelled as M (typically, but not necessarily, a mobile node) and B (an anchor node).
  • Node M transmits a beacon first, followed by node B after a delay of ⁇ MB determined by the beacon schedule (see FIG. 5 ). After a delay of ⁇ SF (the superframe length), this sequence is repeated, as illustrated in FIG. 8 a .
  • the beacons are transmitted at times t 1 , t 3 , t 5 and t 7 , and received at times t 2 , t 4 , t 6 and t 8 .
  • the difference between the transmit time and the receive time e.g.
  • t 2 ⁇ t 1 is the sum of the propagation delay through the transmitter electronics ( ⁇ i tx where i can be M or B), the propagation time through the air (d ij /c where d ij is distance between the two nodes, c is speed of light, and j can be B or M), and the propagation delay through the receiver electronics ( ⁇ j rx ).
  • An estimate of the frequency difference between the pair of nodes can be made at node M as follows:
  • ⁇ MB is the frequency offset of the local clocks of the node pair
  • ⁇ MB is the Doppler frequency shift due to the radial component of the relative motion between the node pair.
  • ⁇ MB terms between a mobile node and multiple anchor nodes it is possible to estimate the velocity of the mobile node without determining range or location.
  • the round trip delay measurement requires measurements in both directions between the pair of nodes.
  • the uncorrected round trip delay, using the first pair of beacons in FIG. 8 a is:
  • T MB and D M are directly determined from the measured data, and ⁇ MB is known from the beacon TDMA schedule; if not, it can be readily estimated from the TOA data as follows:
  • the location of the mobile node (hence d BM1 ) is unknown, and the propagation delay ⁇ i for each node may be unknown.
  • corrected round trip delay measurements are first made between anchor nodes and mobile nodes (steps 754 and 780 ).
  • the use of round trip delay measurements for removing the requirement for time synchronisation is well known, but using the corrected round trip delay computed as below, the effects of frequency offset and relative motion can also be removed.
  • An important feature of this correction for motion and frequency offset is that it is applied locally to each node pair, and no global processing is required. Note that the motion is corrected to the time at which the mobile node transmits, hence all ranges between this mobile node and multiple anchor nodes are corrected to the same time, compensating for the effect of constant velocity motion.
  • the propagation delay ⁇ B of the anchor nodes is either known from prior calibration or computed at step 725 using corrected round trip delay measurements between anchor nodes as described below.
  • round trip measurements between mobile nodes are not used, but these measurements may be used for other purposes, e.g. cooperative localisation.
  • ⁇ ⁇ is ⁇ ⁇ T MB - ⁇ M - ⁇ B - ⁇ MB ⁇ D M .
  • the range between the pair of nodes is therefore computed (step 785 or 756 ) as:
  • the location of the mobile node is estimated (step 790 or 758 ).
  • ⁇ ⁇ is ⁇ ⁇ T MB - ⁇ B - ⁇ MB ⁇ D M .
  • the pseudo-range between the pair of nodes is therefore computed (step 756 or 785 ) as:
  • p BM d BM + c ⁇ ⁇ ⁇ M 2 ⁇ c ⁇ T MB - ⁇ B - ⁇ MB ⁇ D M 2 . ( 6 )
  • Pre-filtering of the range data improves localisation accuracy by eliminating bad measurements prior to the localisation steps 758 and 790 .
  • an improved estimate of the true range at any given time can be determined by a variety of filtering and interpolation operations. Applying these operations prior to estimation of the node location using either the POCS or MMSE approaches described below can result in improved estimation accuracy. Because these operations act on the range data before the localisation step, the result is quite different to applying a filter (such as a Kalman filter or non-linear filter) to the estimated locations.
  • a filter such as a Kalman filter or non-linear filter
  • any of a number of filtering operations can be applied to the range data, taking into account a priori information about the characteristics of the motion of the mobile node.
  • filtering may include for example linear filters (e.g. low pass filter and Kalman filter) or non-linear filters (e.g. median filter).
  • linear filters e.g. low pass filter and Kalman filter
  • non-linear filters e.g. median filter
  • a nonlinear filter which replaces infeasible measurements with a value extrapolated from past measurements can be used.
  • One embodiment of such a filter limits the maximum difference in range between the minimum range from of any of the previous 5 superframes and the range from the current superframe.
  • the same filtering operations can be applied to pseudo-range data between a given mobile node and anchor nodes, as the distance offset between the pseudo-range and the (unknown) true range is the same for each of these measurements.
  • the MMSE cost function to estimate the mobile node location using the range measurements between a mobile node and K anchor nodes is
  • w i is an optional weight that is preferably inversely proportional to the noise variance in the range measurement.
  • the locations x i of the anchor nodes are known.
  • the mobile node location and propagation delay are estimated from the pseudo-range measurements (step 758 or 790 ) as
  • Finding the minimising argument of either cost function is a non-linear problem with many solution strategies.
  • An initial linear solution followed by one or more non-linear iterations using a Taylor expansion (usually less than five iterations are required) is preferable.
  • bad range measurements e.g. ones with a significant bias due to multipath
  • An algorithm for doing this is given by the pseudocode in Appendix A.
  • the location and the error in the location estimate are computed at line 5 . If the error is less than a threshold, or the number of ranges is less than or equal to a minimum number, the “repeat” loop at line 4 terminates.
  • Each range or pseudo-range measurement is then excluded in turn at line 9 , which recomputes the location and the error in the location estimate with the remaining range or pseudo-range measurements.
  • the location error estimate is computed as the product of an estimate of the range error and the GDOP (geometric dilution of precision) and is given by:
  • Equation (9) is based on the simplifying assumption that the noise in the range (or pseudo-range) measurements is independent and identically distributed, which while not strictly true has been found to work very well with real data.
  • the GDOP is calculated as a Cramer-Rao lower bound (see e.g. Larsson, E.G., “Cramer-Rao bound analysis of distributed positioning in sensor networks,” IEEE Signal Processing Letters , vol. 11, no. 3, pp. 334-337, March 2004). This calculation depends upon the location of the anchor nodes, and whether or not the mobile node propagation delay is being estimated.
  • the other round-trip localisation approach is the Projection Onto Convex Sets (POCS) algorithm (step 758 or 790 ), where each constraint set is a circle centred on an anchor node with the radius given by the estimated range to that anchor node.
  • the POCS algorithm may be extended to 3 dimensional locations by taking the constraint sets as spheres rather than circles.
  • the POCS algorithm applies no penalty for the range to the mobile node being less than or equal to the estimated range.
  • the POCS algorithm gives good results when large positive errors are likely, such as in indoor environments where the direct path may be severely attenuated by intervening walls.
  • a point in the intersection of the constraint sets is found by an iterative process, illustrated in FIG. 9 .
  • Constraints sets for three anchor nodes labelled B 1 , B 2 and B 3 are shown as circles centred at each anchor node, with radii equal to the respective ranges from each anchor node.
  • a random starting point e.g. 900 or 910 , is updated by projecting onto each of the constraint sets in turn. After a small number of iterations (generally less than 10), the point will be in the (shaded) intersection region 920 of the constraint sets. The end point of the path is recorded.
  • the path 915 is taken by the starting point 910 as it is projected onto the constraint sets associated with B 1 , B 2 and B 3 in turn.
  • a second path 905 is taken by a starting point 900 as it is projected onto the sets associated with B 3 , B 1 and B 2 in turn.
  • the intersection of the constraint sets may be empty. This can be detected by determining whether the end point is not inside all the constraint sets after a substantial number of iterations (preferably 20). There are several possible ways of dealing with this case. In one approach, the ranges to one or more of the anchor nodes are increased by a small amount and the constraint set intersection is recomputed. This is repeated until the intersection of the constraint sets is non-empty. In an alternative approach, a number of different starting points are chosen, and the POCS algorithm is run for a fixed number of iterations for each starting point, and the resulting end points are averaged. In yet another approach, only a single starting point is used, and the solution point is given by the average of the end points over a number of steps of the iterative algorithm.
  • intersection of the constraint sets may be empty, it may also be very large, indicated by determining whether multiple end points are widely dispersed. This can be dealt with using strategies similar to those for the case of an empty intersection discussed above.
  • the range to at least one of the anchor nodes is decreased and the POCS algorithm run again. This is repeated until the intersection region shrinks to a small size.
  • the end point for multiple different starting points may be averaged to estimate the centroid of the constraint set intersection region. In FIG. 9 , the end point for two different starting points is shown. Taking the median of several such end points gives a point near the centroid of the shaded intersection region. The median is the location estimate for the mobile node.
  • the location of a mobile node is estimated based on a single beacon from the mobile node to each anchor node. This requires time synchronisation of the anchor nodes (step 740 ) at the time at which the beacon is sent. If the propagation delay of the mobile node is known, it is possible to time synchronise the mobile node to the other nodes and what is generally called a TOA localisation algorithm may be used.
  • TDOA Time Difference Of Arrival
  • the mobile node is time synchronised, given the transmit time from the mobile t M and a receive time at each anchor node i of t rx,i the measured range between the node pairs is given by
  • a set of such measurements can be used as input for the robust MMSE algorithm based on range described above with reference to equation (7). Note that it is not usually convenient to calculate the separate transmit and receive delays, so this localisation algorithm is preferably not used.
  • the measured pseudo-range (step 745 ) is
  • a set of such measurements can be used as input for the robust MMSE TDOA algorithm based on pseudo-range described above with reference to equation (8), except where above the unknown range offset was c ⁇ M /2, in this case it is c(t M + ⁇ M tx ).
  • the propagation delay of anchor nodes at known locations can be readily computed (step 725 ) using the corrected round trip delay
  • equation (4) the distance between the anchor nodes i and j is known, as are ⁇ ij and D i using equation (1), so the only unknowns are the propagation delays of the two anchor nodes.
  • equation (4) may be rewritten as
  • the time offset between anchor nodes is continually changing due to the offset in node clock frequencies (which themselves vary over time). Hence, for the calculation of mobile node location using TDOA, the time offset between the anchor nodes needs to be determined at the time that the mobile node transmitted its beacon (step 740 ). Assume that anchor node i transmits a beacon at t 1 that is received by anchor node j at t 2 . The difference between the measured receive and transmit times at time t 1 is
  • t 2 j - t 1 i ⁇ ⁇ j ⁇ ( d ij / c + ⁇ i tx + ⁇ j rx - t 0 , j ) + ⁇ i ⁇ t 0 , i ⁇ ⁇ t 0 , i - t 0 , j + d ij / c + ⁇ i tx + ⁇ j rx .
  • d ij is known as the anchor node locations are known, and ⁇ i tx and ⁇ j rx can be solved for, but are actually known from previous calibration or separate anchor node propagation delay calculation (step 725 ).
  • the value ⁇ iM can be measured using the receive time of the beacon from the mobile node at node i, however a more robust measurement is to form a least squares estimate of all beacon transmit times over all measurements in a superframe.

Landscapes

  • Engineering & Computer Science (AREA)
  • Radar, Positioning & Navigation (AREA)
  • Remote Sensing (AREA)
  • Physics & Mathematics (AREA)
  • General Physics & Mathematics (AREA)
  • Computer Networks & Wireless Communication (AREA)
  • Mobile Radio Communication Systems (AREA)
  • Position Fixing By Use Of Radio Waves (AREA)
US13/002,640 2008-07-04 2009-07-03 Wireless Localisation System Abandoned US20110188389A1 (en)

Applications Claiming Priority (3)

Application Number Priority Date Filing Date Title
AU2008903441 2008-07-04
AU2008903441A AU2008903441A0 (en) 2008-07-04 Wireless localisation system
PCT/AU2009/000863 WO2010000036A1 (fr) 2008-07-04 2009-07-03 Système de localisation sans fil

Related Parent Applications (1)

Application Number Title Priority Date Filing Date
PCT/AU2009/000863 A-371-Of-International WO2010000036A1 (fr) 2008-07-04 2009-07-03 Système de localisation sans fil

Related Child Applications (1)

Application Number Title Priority Date Filing Date
US15/255,011 Continuation US10338194B2 (en) 2008-07-04 2016-09-01 Wireless localisation system

Publications (1)

Publication Number Publication Date
US20110188389A1 true US20110188389A1 (en) 2011-08-04

Family

ID=41465420

Family Applications (3)

Application Number Title Priority Date Filing Date
US13/002,640 Abandoned US20110188389A1 (en) 2008-07-04 2009-07-03 Wireless Localisation System
US15/255,011 Active 2030-03-17 US10338194B2 (en) 2008-07-04 2016-09-01 Wireless localisation system
US16/454,841 Active 2029-11-14 US11061106B2 (en) 2008-07-04 2019-06-27 Wireless localisation system

Family Applications After (2)

Application Number Title Priority Date Filing Date
US15/255,011 Active 2030-03-17 US10338194B2 (en) 2008-07-04 2016-09-01 Wireless localisation system
US16/454,841 Active 2029-11-14 US11061106B2 (en) 2008-07-04 2019-06-27 Wireless localisation system

Country Status (4)

Country Link
US (3) US20110188389A1 (fr)
EP (2) EP2674775B1 (fr)
AU (1) AU2009266425B2 (fr)
WO (1) WO2010000036A1 (fr)

Cited By (38)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US8265011B2 (en) 2010-11-02 2012-09-11 Diani Systems, Inc. High resolution wireless indoor positioning system for legacy standards-based narrowband mobile radios
US20120231786A1 (en) * 2011-03-09 2012-09-13 Telcordia Technologies, Inc. System and method for quantifying anchor placement impact placement on location accuracy
US20130072217A1 (en) * 2011-09-19 2013-03-21 Qualcomm Atheros, Inc. Time of arrival based positioning system
US8457655B2 (en) 2011-09-19 2013-06-04 Qualcomm Incorporated Hybrid time of arrival based positioning system
US8489114B2 (en) 2011-09-19 2013-07-16 Qualcomm Incorporated Time difference of arrival based positioning system
US8509809B2 (en) 2011-06-10 2013-08-13 Qualcomm Incorporated Third party device location estimation in wireless communication networks
US8547870B2 (en) 2011-06-07 2013-10-01 Qualcomm Incorporated Hybrid positioning mechanism for wireless communication devices
US8755304B2 (en) 2011-10-21 2014-06-17 Qualcomm Incorporated Time of arrival based positioning for wireless communication systems
US8824325B2 (en) 2011-12-08 2014-09-02 Qualcomm Incorporated Positioning technique for wireless communication system
US20140292568A1 (en) * 2013-03-26 2014-10-02 Peter Fleming Radiobeacon stations, user devices, location determination systems, methods for controlling a radiobeacon station, methods for controlling a user device, and location determination methods
WO2014193335A1 (fr) * 2013-05-26 2014-12-04 Intel IP Corporation Appareil, système et procédé d'estimation d'une localisation d'un dispositif mobile
US8909244B2 (en) 2011-06-28 2014-12-09 Qualcomm Incorporated Distributed positioning mechanism for wireless communication devices
US9014172B2 (en) 2010-11-02 2015-04-21 Diani Systems, Inc. High resolution wireless indoor positioning system for legacy standards-based narrowband mobile radios
WO2016023069A1 (fr) * 2014-08-15 2016-02-18 Commonwealth Scientific And Industrial Research Organisation Procédé d'établissement d'un système de poursuite basé sur une plage utilisant un système de coordonnées de poursuite
US9305568B2 (en) * 2014-04-08 2016-04-05 Doppler Labs, Inc. Active acoustic filter with socially determined location-based filter characteristics
US9557960B2 (en) 2014-04-08 2017-01-31 Doppler Labs, Inc. Active acoustic filter with automatic selection of filter parameters based on ambient sound
US9560437B2 (en) 2014-04-08 2017-01-31 Doppler Labs, Inc. Time heuristic audio control
US9572125B1 (en) * 2014-09-03 2017-02-14 Symantec Corporation Systems and methods for locating unrecognized computing devices
US9584899B1 (en) 2015-11-25 2017-02-28 Doppler Labs, Inc. Sharing of custom audio processing parameters
US9648436B2 (en) 2014-04-08 2017-05-09 Doppler Labs, Inc. Augmented reality sound system
US9678709B1 (en) 2015-11-25 2017-06-13 Doppler Labs, Inc. Processing sound using collective feedforward
US9703524B2 (en) 2015-11-25 2017-07-11 Doppler Labs, Inc. Privacy protection in collective feedforward
US20170212211A1 (en) * 2013-03-15 2017-07-27 Nextnav, Llc Systems and methods for improving the performance of a timing-based radio positioning network using estimated range biases
US9736264B2 (en) 2014-04-08 2017-08-15 Doppler Labs, Inc. Personal audio system using processing parameters learned from user feedback
US20170311125A1 (en) * 2014-10-07 2017-10-26 Commonwealth Scientific And Industrial Research Organisation Method of setting up a tracking system
US9810764B2 (en) 2013-09-30 2017-11-07 AT&T Intellectual Preoperty I, L.P. Systems and methods for high precision indoor location tracking
US9825598B2 (en) 2014-04-08 2017-11-21 Doppler Labs, Inc. Real-time combination of ambient audio and a secondary audio source
US9961486B2 (en) 2014-11-20 2018-05-01 At&T Intellectual Property I, L.P. Smart machine to machine behavior tracking
US10338194B2 (en) 2008-07-04 2019-07-02 Commonwealth Scientific And Industrial Research Organisation Wireless localisation system
CN110007268A (zh) * 2019-02-01 2019-07-12 华东师范大学 一种基于锚节点差分时间同步和“Taylor”协同的定位系统
CN110022526A (zh) * 2019-04-01 2019-07-16 黑龙江省科学院自动化研究所 一种无线节点自组网的定位方法
CN110067598A (zh) * 2019-04-29 2019-07-30 中国矿业大学(北京) 一种基于人员定位的矿井下灾害报警方法
US10820170B1 (en) * 2019-09-25 2020-10-27 Mapsted Corp. Time offset based synchronization in mobile device localization
US10853025B2 (en) 2015-11-25 2020-12-01 Dolby Laboratories Licensing Corporation Sharing of custom audio processing parameters
US10976403B2 (en) * 2016-07-04 2021-04-13 Murata Manufacturing Co., Ltd. Position detection system and receiver
US11019457B2 (en) * 2017-09-28 2021-05-25 Lg Electronics Inc. Method for reducing wireless positioning error in multi-node system and terminal therefor
US11145320B2 (en) 2015-11-25 2021-10-12 Dolby Laboratories Licensing Corporation Privacy protection in collective feedforward
JP2022008526A (ja) * 2017-12-21 2022-01-13 オカド・イノベーション・リミテッド 位置決めデバイス、通信システム及び方法

Families Citing this family (14)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US9285454B2 (en) 2011-03-04 2016-03-15 Zih Corp. Method, apparatus, and computer program product for processing received signals for locating
CN106063317B (zh) * 2014-03-27 2019-08-16 华为技术有限公司 业务热点的定位方法及装置
US10802108B2 (en) 2014-07-31 2020-10-13 Symbol Technologies, Llc Two pass detection technique for non-echo pulsed ranging
CN108761388B (zh) * 2018-06-06 2022-02-11 上海交通大学 基于uwb高精度测距定位系统的天线延迟校准方法
FR3096129B1 (fr) * 2019-05-15 2021-04-23 Thales Sa procédé de géolocalisation de plateformes se déplaçant en formation, produit programme d'ordinateur et module de géolocalisation associés
US11255980B2 (en) * 2019-06-28 2022-02-22 Sony Corporation Collaborative positioning
CN110856104B (zh) * 2019-11-18 2021-02-19 哈尔滨工业大学 一种联合最小二乘和三边定位的超宽带室内定位方法
KR102293561B1 (ko) * 2019-12-31 2021-08-24 재단법인대구경북과학기술원 이동형 측위 장치 및 위치 측정 방법
CN111277968B (zh) * 2020-01-20 2022-05-03 中山大学 一种基于堆栈自编码器的无线传感器网络非测距定位方法
CN112285652B (zh) * 2020-10-28 2022-06-07 浙江大学 利用单信标虚拟到达时刻差的水下滑翔机定位方法
CN113406612B (zh) * 2021-05-28 2023-08-11 西安空间无线电技术研究所 一种用于半双工系统的双向实时高精度测距方法和测距装置
CN114584919B (zh) * 2022-02-14 2024-04-19 华东师范大学 使用插值方法的uwb室内定位系统
US20230394257A1 (en) * 2022-06-02 2023-12-07 X Development Llc Wireless anchors for asset tracking
FR3141581A1 (fr) * 2022-10-27 2024-05-03 Thales Procédé de radiodiffusion de temps précis par un réseau de balises de positions imprécises

Citations (33)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4799062A (en) * 1987-04-27 1989-01-17 Axonn Corporation Radio position determination method and apparatus
US5056106A (en) * 1990-08-02 1991-10-08 Wang James J Golf course ranging and direction-finding system using spread-spectrum radiolocation techniques
US5438321A (en) * 1991-10-11 1995-08-01 Bernard; Hermanus A. Location system
US5513854A (en) * 1993-04-19 1996-05-07 Daver; Gil J. G. System used for real time acquistion of data pertaining to persons in motion
US5583517A (en) * 1992-08-20 1996-12-10 Nexus 1994 Limited Multi-path resistant frequency-hopped spread spectrum mobile location system
US5805108A (en) * 1996-09-16 1998-09-08 Trimble Navigation Limited Apparatus and method for processing multiple frequencies in satellite navigation systems
US5822363A (en) * 1994-12-19 1998-10-13 Commissariat A L'energie Atomique Transmission process having spectrum spread phase differential modulation adn demodulation using orthogonal pseudorandom sequences
US5859613A (en) * 1996-08-30 1999-01-12 Harris Corporation System and method for geolocating plural remote transmitters
US5912644A (en) * 1997-08-05 1999-06-15 Wang; James J. M. Spread spectrum position determination, ranging and communication system
US6054950A (en) * 1998-01-26 2000-04-25 Multispectral Solutions, Inc. Ultra wideband precision geolocation system
US6169497B1 (en) * 1993-04-01 2001-01-02 Bruno G. Robert Mobile tracking and positioning system
US6185428B1 (en) * 1998-10-07 2001-02-06 Ericsson Inc System and method for adaptively modifying base station transceiver resources for time of arrival measurements
US6204813B1 (en) * 1998-02-20 2001-03-20 Trakus, Inc. Local area multiple object tracking system
US6259894B1 (en) * 1997-12-04 2001-07-10 Lucent Technologies Inc. Method for improved line-of-sight signal detection using RF model parameters
US6275705B1 (en) * 1995-12-22 2001-08-14 Cambridge Positioning Systems Ltd. Location and tracking system
US20010030625A1 (en) * 2000-01-12 2001-10-18 Doles Daniel T. Local clock-referenced DTOA geolocation system with wireless infrastructure
US6414634B1 (en) * 1997-12-04 2002-07-02 Lucent Technologies Inc. Detecting the geographical location of wireless units
US6469665B2 (en) * 2000-04-25 2002-10-22 Koninklijke Philips Electronics N.V. Time of arrival estimation positioning systems
US6483461B1 (en) * 2000-08-24 2002-11-19 Time Domain Corporation Apparatus and method for locating objects in a three-dimensional space
US20020196186A1 (en) * 2001-06-25 2002-12-26 Harris Corporation Method and system for calibrating wireless location systems
US6504483B1 (en) * 1998-03-23 2003-01-07 Time Domain Corporation System and method for using impulse radio technology to track and monitor animals
US20030092448A1 (en) * 2001-08-16 2003-05-15 Forstrom Howard Scott System for determining position of an emitter
US6795491B2 (en) * 1999-07-22 2004-09-21 Aether Wire & Location Spread spectrum localizers
US6804494B2 (en) * 2001-06-11 2004-10-12 Qualcomm Inc. System and method for the detection and compensation of radio signal time of arrival errors
US6831603B2 (en) * 2002-03-12 2004-12-14 Menache, Llc Motion tracking system and method
US20050026563A1 (en) * 2003-08-01 2005-02-03 Leeper David G. Apparatus and associated methods for precision ranging measurements in a wireless communication environment
US6968194B2 (en) * 2002-08-20 2005-11-22 Aeroscout, Ltd. Method and system for synchronizing location finding measurements in a wireless local area network
US7009561B2 (en) * 2003-03-11 2006-03-07 Menache, Llp Radio frequency motion tracking system and method
US20060066485A1 (en) * 2004-09-24 2006-03-30 Guohua Min Wireless tracking system based upon phase differences
US7026992B1 (en) * 2005-03-31 2006-04-11 Deere & Company Method for configuring a local positioning system
US20060224308A1 (en) * 2005-03-31 2006-10-05 Deere & Company, A Delaware Corporation System and method for determining a position of a vehicle
US7286624B2 (en) * 2003-07-03 2007-10-23 Navcom Technology Inc. Two-way RF ranging system and method for local positioning
US20080130604A1 (en) * 2006-12-05 2008-06-05 Wherenet Corp. Location system for wireless local area network (wlan) using rssi and time difference of arrival (tdoa) processing

Family Cites Families (19)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB1351185A (en) 1970-05-07 1974-04-24 Dynell Elec Radio navigation receivers
US5422646A (en) 1983-02-24 1995-06-06 The United States Of America As Represented By The Secretary Of The Navy High frequency MTI radar
JPS6217304A (ja) 1985-07-15 1987-01-26 Mitsubishi Heavy Ind Ltd 蒸気タ−ビン
US5600706A (en) * 1992-04-08 1997-02-04 U S West, Inc. Method and system for determining the position of a mobile receiver
US5469409A (en) * 1994-03-14 1995-11-21 Motorola, Inc. Method for clock calibration in a position determination system
US5931889A (en) * 1995-01-24 1999-08-03 Massachusetts Institute Of Technology Clock-aided satellite navigation receiver system for monitoring the integrity of satellite signals
US6215442B1 (en) * 1997-02-03 2001-04-10 Snaptrack, Inc. Method and apparatus for determining time in a satellite positioning system
AU6442798A (en) 1997-02-27 1998-09-18 Trakus, Inc. Local area multiple object tracking system
GB9807540D0 (en) 1998-04-09 1998-06-10 Orad Hi Tec Systems Ltd Tracking system for sports
US6453168B1 (en) 1999-08-02 2002-09-17 Itt Manufacturing Enterprises, Inc Method and apparatus for determining the position of a mobile communication device using low accuracy clocks
AU2001237430A1 (en) 2000-03-06 2001-09-17 Cairos Technologies Ag Device for detecting the position and/or movement of objects and/or living things
US6876326B2 (en) 2001-04-23 2005-04-05 Itt Manufacturing Enterprises, Inc. Method and apparatus for high-accuracy position location using search mode ranging techniques
KR100483801B1 (ko) 2002-10-30 2005-04-20 한국철도기술연구원 위상차를 이용한 이동체의 위치 추적 및 운행 관리 시스템
US7110777B2 (en) 2002-11-06 2006-09-19 Charles Duncan Apparatus and method for tracking the location and position of an individual using an accelerometer
JP3762399B2 (ja) 2003-08-28 2006-04-05 三菱電機株式会社 追跡システム及び発信機
US7970574B2 (en) * 2005-06-22 2011-06-28 The Board Of Trustees Of The Leland Stanford Jr. University Scalable sensor localization for wireless sensor networks
US8175613B2 (en) * 2006-08-04 2012-05-08 Misonimo Chi Acquisitions L.L.C. Systems and methods for determining location of devices within a wireless network
KR101417737B1 (ko) * 2007-11-13 2014-08-07 삼성전자주식회사 센서를 구비한 실내 측위 시스템 및 그 위치 확인 방법
EP2674775B1 (fr) 2008-07-04 2017-01-11 Commonwealth Scientific and Industrial Research Organization Système de localisation sans fil

Patent Citations (33)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4799062A (en) * 1987-04-27 1989-01-17 Axonn Corporation Radio position determination method and apparatus
US5056106A (en) * 1990-08-02 1991-10-08 Wang James J Golf course ranging and direction-finding system using spread-spectrum radiolocation techniques
US5438321A (en) * 1991-10-11 1995-08-01 Bernard; Hermanus A. Location system
US5583517A (en) * 1992-08-20 1996-12-10 Nexus 1994 Limited Multi-path resistant frequency-hopped spread spectrum mobile location system
US6169497B1 (en) * 1993-04-01 2001-01-02 Bruno G. Robert Mobile tracking and positioning system
US5513854A (en) * 1993-04-19 1996-05-07 Daver; Gil J. G. System used for real time acquistion of data pertaining to persons in motion
US5822363A (en) * 1994-12-19 1998-10-13 Commissariat A L'energie Atomique Transmission process having spectrum spread phase differential modulation adn demodulation using orthogonal pseudorandom sequences
US6275705B1 (en) * 1995-12-22 2001-08-14 Cambridge Positioning Systems Ltd. Location and tracking system
US5859613A (en) * 1996-08-30 1999-01-12 Harris Corporation System and method for geolocating plural remote transmitters
US5805108A (en) * 1996-09-16 1998-09-08 Trimble Navigation Limited Apparatus and method for processing multiple frequencies in satellite navigation systems
US5912644A (en) * 1997-08-05 1999-06-15 Wang; James J. M. Spread spectrum position determination, ranging and communication system
US6414634B1 (en) * 1997-12-04 2002-07-02 Lucent Technologies Inc. Detecting the geographical location of wireless units
US6259894B1 (en) * 1997-12-04 2001-07-10 Lucent Technologies Inc. Method for improved line-of-sight signal detection using RF model parameters
US6054950A (en) * 1998-01-26 2000-04-25 Multispectral Solutions, Inc. Ultra wideband precision geolocation system
US6204813B1 (en) * 1998-02-20 2001-03-20 Trakus, Inc. Local area multiple object tracking system
US6504483B1 (en) * 1998-03-23 2003-01-07 Time Domain Corporation System and method for using impulse radio technology to track and monitor animals
US6185428B1 (en) * 1998-10-07 2001-02-06 Ericsson Inc System and method for adaptively modifying base station transceiver resources for time of arrival measurements
US6795491B2 (en) * 1999-07-22 2004-09-21 Aether Wire & Location Spread spectrum localizers
US20010030625A1 (en) * 2000-01-12 2001-10-18 Doles Daniel T. Local clock-referenced DTOA geolocation system with wireless infrastructure
US6469665B2 (en) * 2000-04-25 2002-10-22 Koninklijke Philips Electronics N.V. Time of arrival estimation positioning systems
US6483461B1 (en) * 2000-08-24 2002-11-19 Time Domain Corporation Apparatus and method for locating objects in a three-dimensional space
US6804494B2 (en) * 2001-06-11 2004-10-12 Qualcomm Inc. System and method for the detection and compensation of radio signal time of arrival errors
US20020196186A1 (en) * 2001-06-25 2002-12-26 Harris Corporation Method and system for calibrating wireless location systems
US20030092448A1 (en) * 2001-08-16 2003-05-15 Forstrom Howard Scott System for determining position of an emitter
US6831603B2 (en) * 2002-03-12 2004-12-14 Menache, Llc Motion tracking system and method
US6968194B2 (en) * 2002-08-20 2005-11-22 Aeroscout, Ltd. Method and system for synchronizing location finding measurements in a wireless local area network
US7009561B2 (en) * 2003-03-11 2006-03-07 Menache, Llp Radio frequency motion tracking system and method
US7286624B2 (en) * 2003-07-03 2007-10-23 Navcom Technology Inc. Two-way RF ranging system and method for local positioning
US20050026563A1 (en) * 2003-08-01 2005-02-03 Leeper David G. Apparatus and associated methods for precision ranging measurements in a wireless communication environment
US20060066485A1 (en) * 2004-09-24 2006-03-30 Guohua Min Wireless tracking system based upon phase differences
US7026992B1 (en) * 2005-03-31 2006-04-11 Deere & Company Method for configuring a local positioning system
US20060224308A1 (en) * 2005-03-31 2006-10-05 Deere & Company, A Delaware Corporation System and method for determining a position of a vehicle
US20080130604A1 (en) * 2006-12-05 2008-06-05 Wherenet Corp. Location system for wireless local area network (wlan) using rssi and time difference of arrival (tdoa) processing

Cited By (53)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US10338194B2 (en) 2008-07-04 2019-07-02 Commonwealth Scientific And Industrial Research Organisation Wireless localisation system
US11061106B2 (en) 2008-07-04 2021-07-13 Commonwealth Scientific And Industrial Research Organisation Wireless localisation system
US8265011B2 (en) 2010-11-02 2012-09-11 Diani Systems, Inc. High resolution wireless indoor positioning system for legacy standards-based narrowband mobile radios
US9014172B2 (en) 2010-11-02 2015-04-21 Diani Systems, Inc. High resolution wireless indoor positioning system for legacy standards-based narrowband mobile radios
US20120231786A1 (en) * 2011-03-09 2012-09-13 Telcordia Technologies, Inc. System and method for quantifying anchor placement impact placement on location accuracy
US8577362B2 (en) * 2011-03-09 2013-11-05 Telcordia Technologies, Inc. System and method for quantifying anchor placement impact placement on location accuracy
US8547870B2 (en) 2011-06-07 2013-10-01 Qualcomm Incorporated Hybrid positioning mechanism for wireless communication devices
US8509809B2 (en) 2011-06-10 2013-08-13 Qualcomm Incorporated Third party device location estimation in wireless communication networks
US8909244B2 (en) 2011-06-28 2014-12-09 Qualcomm Incorporated Distributed positioning mechanism for wireless communication devices
US9332383B2 (en) 2011-09-19 2016-05-03 Qualcomm Incorporated Time of arrival based positioning system
KR101626514B1 (ko) 2011-09-19 2016-06-01 퀄컴 인코포레이티드 도달 시간 기반 포지셔닝 시스템
US20130072217A1 (en) * 2011-09-19 2013-03-21 Qualcomm Atheros, Inc. Time of arrival based positioning system
US8457655B2 (en) 2011-09-19 2013-06-04 Qualcomm Incorporated Hybrid time of arrival based positioning system
US8489114B2 (en) 2011-09-19 2013-07-16 Qualcomm Incorporated Time difference of arrival based positioning system
KR20140069203A (ko) * 2011-09-19 2014-06-09 퀄컴 인코포레이티드 도달 시간 기반 포지셔닝 시스템
US8521181B2 (en) * 2011-09-19 2013-08-27 Qualcomm Incorporated Time of arrival based positioning system
US8755304B2 (en) 2011-10-21 2014-06-17 Qualcomm Incorporated Time of arrival based positioning for wireless communication systems
US8824325B2 (en) 2011-12-08 2014-09-02 Qualcomm Incorporated Positioning technique for wireless communication system
US10598757B2 (en) * 2013-03-15 2020-03-24 Nextnav, Llc Systems and methods for improving the performance of a timing-based radio positioning network using estimated range biases
US20170212211A1 (en) * 2013-03-15 2017-07-27 Nextnav, Llc Systems and methods for improving the performance of a timing-based radio positioning network using estimated range biases
US20140292568A1 (en) * 2013-03-26 2014-10-02 Peter Fleming Radiobeacon stations, user devices, location determination systems, methods for controlling a radiobeacon station, methods for controlling a user device, and location determination methods
WO2014193335A1 (fr) * 2013-05-26 2014-12-04 Intel IP Corporation Appareil, système et procédé d'estimation d'une localisation d'un dispositif mobile
US9629116B2 (en) 2013-05-26 2017-04-18 Intel IP Corporation Apparatus, system and method of estimating a location of a mobile device
US9810764B2 (en) 2013-09-30 2017-11-07 AT&T Intellectual Preoperty I, L.P. Systems and methods for high precision indoor location tracking
US9648436B2 (en) 2014-04-08 2017-05-09 Doppler Labs, Inc. Augmented reality sound system
US9557960B2 (en) 2014-04-08 2017-01-31 Doppler Labs, Inc. Active acoustic filter with automatic selection of filter parameters based on ambient sound
US9305568B2 (en) * 2014-04-08 2016-04-05 Doppler Labs, Inc. Active acoustic filter with socially determined location-based filter characteristics
US9524731B2 (en) 2014-04-08 2016-12-20 Doppler Labs, Inc. Active acoustic filter with location-based filter characteristics
US9825598B2 (en) 2014-04-08 2017-11-21 Doppler Labs, Inc. Real-time combination of ambient audio and a secondary audio source
US9560437B2 (en) 2014-04-08 2017-01-31 Doppler Labs, Inc. Time heuristic audio control
US9736264B2 (en) 2014-04-08 2017-08-15 Doppler Labs, Inc. Personal audio system using processing parameters learned from user feedback
WO2016023069A1 (fr) * 2014-08-15 2016-02-18 Commonwealth Scientific And Industrial Research Organisation Procédé d'établissement d'un système de poursuite basé sur une plage utilisant un système de coordonnées de poursuite
US10989531B2 (en) 2014-08-15 2021-04-27 Commonwealth Scientific And Industrial Research Organisation Method of setting-up a range-based tracking system utilizing a tracking coordinate system
US10015768B1 (en) * 2014-09-03 2018-07-03 Symantec Corporation Systems and methods for locating unrecognized computing devices
US9572125B1 (en) * 2014-09-03 2017-02-14 Symantec Corporation Systems and methods for locating unrecognized computing devices
US20170311125A1 (en) * 2014-10-07 2017-10-26 Commonwealth Scientific And Industrial Research Organisation Method of setting up a tracking system
US9961486B2 (en) 2014-11-20 2018-05-01 At&T Intellectual Property I, L.P. Smart machine to machine behavior tracking
US10587985B2 (en) 2014-11-20 2020-03-10 At&T Intellectual Property I, L.P. Smart machine to machine behavior tracking
US10275210B2 (en) 2015-11-25 2019-04-30 Dolby Laboratories Licensing Corporation Privacy protection in collective feedforward
US9678709B1 (en) 2015-11-25 2017-06-13 Doppler Labs, Inc. Processing sound using collective feedforward
US11145320B2 (en) 2015-11-25 2021-10-12 Dolby Laboratories Licensing Corporation Privacy protection in collective feedforward
US10853025B2 (en) 2015-11-25 2020-12-01 Dolby Laboratories Licensing Corporation Sharing of custom audio processing parameters
US9703524B2 (en) 2015-11-25 2017-07-11 Doppler Labs, Inc. Privacy protection in collective feedforward
US9769553B2 (en) 2015-11-25 2017-09-19 Doppler Labs, Inc. Adaptive filtering with machine learning
US9584899B1 (en) 2015-11-25 2017-02-28 Doppler Labs, Inc. Sharing of custom audio processing parameters
US10976403B2 (en) * 2016-07-04 2021-04-13 Murata Manufacturing Co., Ltd. Position detection system and receiver
US11019457B2 (en) * 2017-09-28 2021-05-25 Lg Electronics Inc. Method for reducing wireless positioning error in multi-node system and terminal therefor
JP2022008526A (ja) * 2017-12-21 2022-01-13 オカド・イノベーション・リミテッド 位置決めデバイス、通信システム及び方法
JP7159418B2 (ja) 2017-12-21 2022-10-24 オカド・イノベーション・リミテッド 位置決めデバイス、通信システム及び方法
CN110007268A (zh) * 2019-02-01 2019-07-12 华东师范大学 一种基于锚节点差分时间同步和“Taylor”协同的定位系统
CN110022526A (zh) * 2019-04-01 2019-07-16 黑龙江省科学院自动化研究所 一种无线节点自组网的定位方法
CN110067598A (zh) * 2019-04-29 2019-07-30 中国矿业大学(北京) 一种基于人员定位的矿井下灾害报警方法
US10820170B1 (en) * 2019-09-25 2020-10-27 Mapsted Corp. Time offset based synchronization in mobile device localization

Also Published As

Publication number Publication date
US20160370455A1 (en) 2016-12-22
EP2674775B1 (fr) 2017-01-11
EP2674775A1 (fr) 2013-12-18
US11061106B2 (en) 2021-07-13
AU2009266425A1 (en) 2010-01-07
EP2307902A1 (fr) 2011-04-13
EP2307902A4 (fr) 2011-09-07
US20190317184A1 (en) 2019-10-17
EP2307902B1 (fr) 2013-09-25
WO2010000036A1 (fr) 2010-01-07
AU2009266425B2 (en) 2015-02-05
US10338194B2 (en) 2019-07-02

Similar Documents

Publication Publication Date Title
US11061106B2 (en) Wireless localisation system
US10932094B2 (en) Method and system for radiolocation asset tracking via a mesh network
US8165150B2 (en) Method and system for wireless LAN-based indoor position location
KR100671283B1 (ko) 순차 송수신 방식을 이용한 비동기 무선 측위 시스템 및방법
US8644850B2 (en) Radio navigation
CN109375167B (zh) 井下无源动目标定位方法
US20120330600A1 (en) Electronic device, positioning method, positioning system, computer program product, and computer-readable recording medium
JP2003501664A (ja) 狭帯域ベースのナビゲーション方法および装置
JP2011047915A (ja) 無線測位システムおよび測位方法
KR101135201B1 (ko) 무선 네트워크에서 가속도 위치 정보를 이용한 수신신호강도 기반 위치 측정 방법 및 위치측정 시스템
AU2019200145B9 (en) Wireless localisation system
JP2007533968A5 (fr)
JP2007533968A (ja) 無線による自己測量位置決定方法
Moschevikin et al. The impact of nlos components in time-of-flight networks for indoor positioning systems
Youssef et al. Pedestrian Tracking Solution Combining an Impulse Radio Handset Transmitter with an Ankle‐Mounted Inertial Measurement Unit
US20240103118A1 (en) Method and apparatus that uses radio transmissions for surface mapping
Schröder et al. Inphase: an indoor localization system based on phase difference measurements
EP2309288A1 (fr) Améliorations de ou associées à la navigation par radio
Van Herbruggen et al. Single Anchor Localization by Combining UWB Angle-of-Arrival and Two-Way-Ranging: an Experimental Evaluation of the DW3000
Warnakulasuriya et al. Indoor Positioning Based on Time of Flight and Kalman Filtering Using Ultra-Wideband Sensors
JP2006170892A (ja) 位置計測システム

Legal Events

Date Code Title Description
AS Assignment

Owner name: COMMONWEALTH SCIENTIFIC AND INDUSTRIAL RESEARCH OR

Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNORS:HEDLEY, MARK;HUMPHREY, DAVID ERIC;REEL/FRAME:026159/0859

Effective date: 20110112

STCB Information on status: application discontinuation

Free format text: ABANDONED -- FAILURE TO RESPOND TO AN OFFICE ACTION