WO2013088279A1 - Télémétrie sans fil - Google Patents

Télémétrie sans fil Download PDF

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Publication number
WO2013088279A1
WO2013088279A1 PCT/IB2012/056409 IB2012056409W WO2013088279A1 WO 2013088279 A1 WO2013088279 A1 WO 2013088279A1 IB 2012056409 W IB2012056409 W IB 2012056409W WO 2013088279 A1 WO2013088279 A1 WO 2013088279A1
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WIPO (PCT)
Prior art keywords
receiver
transmitter
receivers
instant
distance
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PCT/IB2012/056409
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English (en)
Inventor
Stephen Michael Pitchers
Aki Sakari HÄRMÄ
Paul Richard Simons
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Koninklijke Philips Electronics N.V.
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Application filed by Koninklijke Philips Electronics N.V. filed Critical Koninklijke Philips Electronics N.V.
Publication of WO2013088279A1 publication Critical patent/WO2013088279A1/fr

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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
    • G01S5/06—Position of source determined by co-ordinating a plurality of position lines defined by path-difference measurements
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04W—WIRELESS COMMUNICATION NETWORKS
    • H04W16/00—Network planning, e.g. coverage or traffic planning tools; Network deployment, e.g. resource partitioning or cells structures
    • H04W16/18—Network planning tools
    • H04W16/20—Network planning tools for indoor coverage or short range network deployment
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04W—WIRELESS COMMUNICATION NETWORKS
    • H04W64/00—Locating users or terminals or network equipment for network management purposes, e.g. mobility management

Definitions

  • the invention relates to: a ranging system, an automatic commissioning system comprising the ranging system, and a ranging method.
  • TDOA time difference of arrival
  • the locus of possible emitter locations is a one half of a two-sheeted hyperboloid. Note that the receivers do not need to know the absolute time at which the pulse was transmitted, only the time difference is needed. It is therefore not required that the clock signals of the receivers are synchronized with the clock signal of the transmitter. For time-of- flight (TOF) measurements, the clocks must be synchronized such that the receivers know when in time the transmitter transmitted the event to be received by the receivers.
  • TOF time-of- flight
  • Adding a third receiver at a third location would provide a second and third TDOA
  • the location problem can be posed as an optimization problem and solved using, for example, a least squares method. Additionally, the TDOA of multiple transmitted events (pulses) from the transmitter can be averaged to improve accuracy.
  • a drawback of the approach using the TDOA measurements is that the intersections of hyperboloids (in 3D space) or hyperbolic functions (in 2D space) do not allow the implementation of existing highly optimized techniques for spherical ranging when performing time-of- flight measurements.
  • existing techniques include, but are not limited to, multilateration and multidimensional scaling.
  • a first aspect of the invention provides a system as claimed in claim 1.
  • a second aspect of the invention provides an automatic commissioning system as claimed in claim 11.
  • a third aspect of the invention provides a method as claimed in claim 15.
  • a system in accordance with the first aspect of the invention determines positions of a wireless transmitter, a first wireless receiver and a second wireless receiver with respect to each other.
  • the transmitter transmits a transmitter signal starting at a transmitter instant.
  • the transmitter signal may be a pulse signal.
  • the first receiver receives this transmitter signal without knowing the transmitter instant.
  • the reception of the transmitter signal by the first receiver indicates a first instant at which the transmitter signal reaches the first receiver.
  • the second receiver receives this transmitter signal without knowing the transmitter instant.
  • the reception of the transmitter signal by the second receiver indicates a second instant at which the transmitter signal reaches the second receiver.
  • the calculator determines the time difference between the first instant and the second instant and the estimator receives this difference and geometrical information comprising a geometrical property of the configuration of the transmitter, the first receiver and the second receiver to obtain an estimated absolute time difference between the transmitter instant and the first instance or the second instance, respectively.
  • the geometrical property comprises at least one of the positions of the transmitter, the first receiver and the second receiver, or uses at least one distance between these positions.
  • the geometrical property may be an approximation of an actual geometrical property. For example, an installation technician may estimate a recurring smallest distance between adjacent receivers just by looking at the real situation or into a building plan.
  • the estimator estimates the common offset in time which exist between the first instant and the second instant and the transmitter instant. Or said differently, the estimator estimates the unknown time period between the transmitter instant and the first instant or second instant. In this manner, the TDOA measurements which provide time differences of arrival of the transmitter signal at the receivers are converted into TOF data providing an estimated time difference between the instant the transmitter emits the signal until the signal is received by one of the receivers.
  • the existing highly optimized techniques for spherical ranging can be implemented on this estimated TOF data.
  • the calculator estimates this unknown time period by using a given position of the transmitter or at least one of the receivers or by using information on the geometry of the configuration of transmitter and receivers.
  • the position of a mobile device in a room can be determined by using the mobile device as the transmitter and having a known configuration of an array of receivers just below or in the ceiling.
  • the distance between the handheld mobile device and the nearest one of the receivers may be estimated to be the vertical distance between the ceiling and the handheld device, for example 2 m for a ceiling of 3 m high.
  • the position of elements in a lighting system should be determined.
  • the elements may comprise lamps, switches and sensors.
  • the transmitter may be a loudspeaker at the position of one of the sensors and the receivers may be mounted at the positions of the lamps.
  • the estimator may compare the measured time differences with a known property of the geometry of the elements. For example, if a building plan is available showing where the elements are positioned in the building, a match may be found between the distances on the plan and measured differences. Or, in a standard grid of lamps at the ceiling a known repetition distance between candidate installation positions may be known.
  • the calculator determines the difference of on the one hand a first distance between a position of the transmitter and a position of the first receiver and on the other hand a second distance between the position of the transmitter and a position of the second receiver.
  • the estimator estimates the distance between the position of the transmitter and the position of the first receiver or the second receiver, respectively.
  • Such distances can directly be found by multiplying the time periods or time differences by the speed of the waves of the wireless transmission through the medium in which the transmitter and receivers are present. For example, if the transmitter is a sound emitter and the receivers are microphones which all are positioned in a room, the speed of the wireless transmission is the speed of sound through air.
  • the transmitters may transmit light or radio waves.
  • a fixed relation exists between the positions of the transmitter, the first receiver and a second receiver with respect to each other.
  • the receivers receive the transmitted signal via a wireless link.
  • This embodiment is in particular relevant for situations wherein the transmitter and receivers have fixed position in a particular frame of reference which as such moves with respect to the earth surface, such as in airplanes or trains. This fixed relation enables an easy determination of the geometrical information.
  • the positions of the transmitter and receivers are stationary with respect to the earth surface and are known from a building plan defining the system of transmitter and receivers.
  • a building plan may be a plan indicating positions of lighting elements for a floor of an office building.
  • the lighting elements may comprise light sources, switches and sensors which are arranged in one of the floors of the building.
  • the system comprises a set of receivers which comprise more than two receivers.
  • the geometrical information comprises the known stationary positions.
  • the estimator constructs a hypotheses tree which has branches which assign the receivers to the stationary positions (or IDs) and determines a probability value for each one of these branches by comparing the measured relative distances between the receivers with the stationary positions to find the most probable assignment.
  • This hypotheses tree approach has the advantage that it avoids spread of sources of errors and reduces the need for geometrical information for example because the height of the ceiling is not required.
  • a known maximum likelihood approach may be used instead of the hypotheses tree approach.
  • the geometric information is based on a known geometrical property of the system such as the shortest relative distance between the receivers.
  • a known geometrical property of the system such as the shortest relative distance between the receivers.
  • the receiver positions are co-located with the positions of light sources. Each one of the receivers may be arranged as close as possible to, or at a known offset (distance and direction) from, the associated one of the light sources. The system is now used to determine the positions of the light sources.
  • the transmitter position is co-located with a sensor position.
  • the senor has to be connected to a controller which receives the sensor output and which controls light sources in the neighborhood of the sensor. It is advantageous if this same controller also controls the transmitter to send the transmitter signal.
  • this same controller also controls the transmitter to send the transmitter signal.
  • TOF measurements can be performed because the controller knows the instant at which the transmitter sends the transmitter signal to the receivers.
  • light sources (and the associated receivers) which are connected to another controller the conversion of the TDOA measurements into the TOF results has to be performed in accordance with the present invention.
  • the automatic commissioning system uses the determined absolute distances between the transmitter and the receivers from the relative distances between the receivers using the conversion of these TDOA measurements in accordance with the present invention to assign IDs to the receivers and transmitters in accordance with the geometrical
  • the items may be light sources such a TLs or any other lamps, or may be loudspeakers conveying particular messages or a particular genre of music intended for a particular room, or may be a heater/cooler or flow regulator for influencing a temperature in a particular room.
  • the sensor may be a proximity sensor detecting the presence of a person in a room, a light sensor or a heat sensor.
  • Fig. 1 schematically shows a system comprising a transmitter and three receivers
  • Fig. 2 schematically shows a timing diagram of the signal send by the transmitter and the signals received by the receivers
  • Fig. 3 shows a block diagram of a circuit driving the transmitter and determining the estimation of the distance between the transmitter and the receivers shown in Fig. 1,
  • Fig. 4 shows a configuration of a spatial distribution of transmitters and receivers in a building and a controller for controlling this configuration
  • Fig. 5 shows a configuration wherein TOF ranging is applied
  • Fig. 6 shows signals in the TOF ranging configuration of Fig. 5
  • Fig. 7 shows a configuration wherein TDOA ranging is applied
  • Fig. 8 shows signals the TDOA ranging configuration of Fig. 7
  • Fig. 9 shows an example of a hypothesis tree
  • Fig. 10 shows an example of how to find the required position
  • Fig. 11 shows an example using the Pythagorean relationship and the difference measurements.
  • Fig. 1 schematically shows a system comprising a transmitter and three receivers.
  • Fig. 1 depicts the relative position of the transmitter Tl and the receivers Rl, R2 and FR.
  • Fig. 1 only shows one transmitter Tl and a set SR of three receivers Rl, R2 and FR, the system may comprise a plurality of transmitters and two or more than three receivers.
  • the position of the transmitter Tl and the receivers Rl and R2 is denoted by PTl, PR1 and PR2, respectively.
  • the position of the receiver FR is not relevant at this moment.
  • Fig. 2 schematically shows a timing diagram of the signal send by the transmitter and the signals received by the receivers. It is assumed that the transmitter Tl sends a signal Tsl at the instant tTl . The emitted signal Tsl is received by the receiver Rl at the instant tRl and by the receiver R2 at the instant tR2.
  • the time difference between the instants tRl and tR2 is indicated by tR12.
  • the time difference between the instants tRl and tTl is denoted by tAl 1 and the time difference between the instants tR2 and tTl is denoted by tA12.
  • the instant tTl may be the starting instant of the transmission, but may alternatively be defined differently, for example an instant at which a pulse of the transmitted signal reaches a maximum value. What counts is that the instants tTl, tRl and tR2 refer to the same property of the signal, for example all to the instant the signal starts occurring at the respective output or input.
  • Fig. 3 shows a block diagram of a circuit driving the transmitter and determining the estimation of the distance between the transmitter and at least one of the receivers shown in Fig. 1.
  • a clock circuit T10 generates a clock signal CLKT to clock a circuit Ti l which produces the transmitter signal Tsl at the instant tTl for wireless communication with the receivers Rl and R2.
  • both the reception circuits RIO and R20 of the receivers Rl and R2, respectively are clocked with the same clock signal CLKR generated by the clock generator 1.
  • the reception circuits RIO and R20 receive the transmitted signal Tsl at the instants tRl and tR2, respectively.
  • the calculator CAL receives these instances tRl and tR2 to calculate the difference DIF.
  • the difference DIF may be the time difference tRl 2 with which the transmitted signal Tsl reaches the two receivers Rl and R2.
  • the difference DIF may be the difference distance ddl2 between the two receivers Rl and R2 and the transmitter Tl, which difference distance ddl2 easily follows from the time difference tR12 if the type of wireless
  • the estimator EST receives this difference DIF and information on the geometry GI of the system shown in Fig. 1.
  • the estimator EST may estimate the time difference tAl 1 between the instant tTl of the transmission of the signal Tsl by the transmitter Tl and the instant tRl of the receipt of the signal Tsl by the receiver Rl, or the estimator EST estimates the time difference tAl 2 between the instant tTl of the transmission of the signal Tsl by the transmitter Tl and the instant tR2 of the receipt of the signal Tsl by the receiver R2.
  • the estimator EST receives information on the geometry of the system shown in Fig. 1. For example, as will be elucidated with respect to the description of the Figs 9 to 11, the relative position of at least one or even all of the transmitter Tl and the receivers Rl and R2 is known, for example from a building plan.
  • the shortest distance between the receivers may be known.
  • a distance between two adjacent ones of the receivers may be known together with an angle between on the one hand a line through the transmitter Tl and the receiver Rl and on the other hand the receiver Rl and the receiver R2 enabling to convert the TDOA measurement between the receivers FR and Rl into TOF time difference or distance between the transmitter Tl and the receiver FR.
  • Fig. 4 shows a configuration of a spatial distribution of transmitters and receivers in a building and a controller for controlling this configuration.
  • the top portion of Fig. 4 shows an example of a geometrical distribution of the transmitters SP1, SP2 (in general referred to as SPi) and the receivers SP111, SP112, SP121, SP122, SP211, SP212, SP221 and SP222 (in general referred to as SPijk).
  • the transmitters SPi may be loudspeakers LSi associated with and positional related to a sensor Si and the receivers SPijk may be microphones Mijk associated with and positional related to light sources Lijk such as lamps or sets of lamps.
  • Fig. 4 may be considered to be a building plan BP of a floor or a section of a floor of an office.
  • the shown building plan BP indicates the positions of the light sources Lijk, the microphones Mijk and the sensors SPi as they are arranged at the ceiling.
  • the configuration is divided in blocks Bl and B2 (in general referred to as Bi) which may correspond to rooms on the floor.
  • the sensor SP1 may detect a presence of a person in the room illuminated by the lamps in the block Bl .
  • the sensor SP1 may sense the ambient illumination or the total illumination in the block Bl .
  • the system may further comprise other devices not arranged at the ceiling such as the shown switch SWi which is intended to switch on/off the lamps in at least one of the blocks Bl or B2. As discussed earlier, any controllable distribution of devices other than the lamps Lijk may be present instead.
  • the bottom portion of Fig. 4 shows the controller CO which receives the TOF data AV from the estimator EST shown in Fig. 3, the geometrical information GI and the sensed information SlPi from the sensors SPi and the switches SWi to supply the control signals CSPi to the light sources Lijk.
  • the TOF data AV from the estimator EST may now provide measurements made by all the microphones Mijk.
  • the conversion from the TDOA measurements into the TOF data AV allows this controller CO to operate according to the known TOF algorithms.
  • the controller CO has to know which output signal CSPi is controlling which light source Lijk and which sensor SPi or switch SWi is inputting a status change to adequately respond on the sensor or switch inputs SIPi.
  • This mapping of the inputs/outputs of the controller CO on the devices (Lijk, Mijk, SPi, LSi, SWi) in the configuration shown in the plan BP requires establishing an identity (ID) of each one of these devices. It is important to find solutions which will simplify or even automate this ID mapping process (also referred to as commissioning process) to optimize the installation procedure.
  • the problem of the auto-commissioning process arises from the difficulty of establishing the ID of each light source Lijk, switch SWi and sensor SPi installed in various positions within the room.
  • the desired functional connections between each lighting source Lijk depend, in general, to their proximity or spatial relationship to other devices, for example the light sources Lijk in a particular room should be controlled by the switches SWi in that same room.
  • the auto-commissioning system should be designed to determine which ID should be assigned to which location within the building. Often building plans BP are available which show the candidate locations where each type of device must be installed and which show the functional connections desired between devices at specific positions on the plan. However, it is often the job of an installation technician to assign the correct network ID to each location shown on the plan after the network has allocated the IDs according to its own internal logic. This assignment can be performed automatically or with a minimum of manual intervention if range measurements of sufficient accuracy are available allowing matching of the measured relative position of devices with the geometry known from the plan. Such an auto-commissioning system accepts range measurements between the light sources Lijk as input and produces a list of switch assignments as output. US2009/0045971 discloses the use of decision trees for automatic commissioning.
  • Acoustic range measurements can provide an accurate positioning in the order of 5 cm. By co-locating a microphone Mijk and a loudspeaker LSi at the position of each light source Lijk we can measure ranges very accurately using TOF techniques.
  • An advantage of acoustic ranging is that the speed of sound is much lower than the speed of light (or the speed of propagation of a radio signal) which makes measurement of arrival times with good precision very practical even with inexpensive sample rate clock sources.
  • LON/DALI or DMX, etc, networking is provided by a number of lighting controllers that typically each drive up to nine lights or luminaires Lijk and interface with up to four sensors SPi, such as passive infrared (PIR) occupancy sensors. It makes sense for the sound processing to be conducted within each lighting controller on the network. This allows us to have all the devices on a single lighting controller connected to a common sound playback and recording system. For example, suppose each lighting controller on the network has one loudspeaker LSi (perhaps at a PIR sensor) and up to nine microphones Mijk (one at each luminaire).
  • PIR passive infrared
  • each luminaire Lijk somewhere around a range circle centered at the location of the PIR sensor SPi.
  • the radius is easily derived from the time-of- flight measurement, subject to the available ranging accuracy; however the angular information is not yet known.
  • information has to be included which is obtained by listening to the sound sent out by other loudspeakers LSi at the positions of other PIR sensors SPi, belonging to neighbouring lighting controllers. If it were able to obtain range circles centered on these PIR sensors SPi (with their associated loudspeakers LSi), everything needed to apply the various techniques to determine the position of the devices would already be available because the standard approach of determining the intersection points of the range circles centered on each PIR sensor SPi could be used. However, due to the limitations on available synchronization as discussed above, it is not possible in such a setup to synchronize all the lighting controllers sufficiently accurately and the direct measure the time-of- flight, and hence the range, is not possible.
  • the above cross-controller measurements wherein the microphones Mijk of one lighting controller receive a signal transmitted by a loudspeaker LSi of another lighting controller take the form of time-difference of arrival values, according to the known principles of time-difference of arrival TDOA ranging.
  • the instant at which this neighbouring loudspeaker LSi produced the sound signal is not known, the precise instants at which the sound was received at each of the microphones Mijk belonging to the other lighting controller than the one belonging to the loudspeaker LSi is known relative to the internal sample clock of this another lighting controller.
  • the time-difference between the arrival of the first signal and the arrival of all the other signals at these microphones Mijk can be measured.
  • the measurement of time-of- flight is possible only when adequate synchronisation can be achieved between the playback of sound at the loudspeaker LSi and the recording made at the microphone Mijk.
  • This is indeed possible when there is a wired connection between the playback and recording systems, at least in the case of acoustic ranging, when the speed of signals on the wired connection is significantly higher than the speed of sound.
  • the loudspeaker LSi and microphone Mijk can be wired to a shared soundcard or lighting controller, that provides synchronisation in terms of its audio sampling rate, which is therefore common to both loudspeaker LSi and microphone Mijk.
  • each lighting device must either include its own playback and recording system, or share such a system with a limited number of neighbouring devices. In the latter case, a limit of around nine devices is anticipated; in a typical office installation each lighting controller is directly wired to perhaps six or nine lights Lijk and several sensing devices LSi. However, these numbers may be different in future systems.
  • time-difference of arrival measurements can be made.
  • These TDOA measurements present a difficulty in that to find the position of a device detected by using time-difference measurements, it requires a hyperbolic solution rather than the preferred circular or spherical solution.
  • TOF used to measure ranges directly it is a relatively straight forward calculation to find the desired position at an intersection between spheres.
  • the measured time- differences result in hyperbolic lines of iso-differences. To find the desired position, it is necessary to find the intersection point of hyperbolic curves, which is more complicated than finding intersections of circles.
  • the present invention discloses a system and a method for converting the time-difference measurements into a close approximation of time-of- flight measurements. This conversion allows to apply the existing highly optimised techniques for spherical ranging, including but not limited to, multilateration, multidimensional scaling. Embodiments in accordance with the invention will be discussed with respect to Figs. 9 to 11.
  • Fig. 5 shows a configuration wherein the known TOF ranging is applied.
  • the first processing system comprises the sensor SPi at the position X and the microphones Mijk at the positions A, B, C and D which all have a wired connection to the processing system P.
  • the second processing system comprises the sensor SPi at the position Y and the microphones Mijk at the positions J, K, L and M which all have a wired connection to the processing system Q.
  • the TOF ranging is possible as will be explained for the first processing system P with respect to Fig. 6.
  • the processing system P can directly calculate the distance between the loudspeaker LSi and the
  • microphones Mijk by counting the number of clock pulses between the instant Tx the processing system P controls the loudspeaker LSi at the position X to produce a sound and the instants RxC, RxD, RxA and RxB at which the produced sound reaches the microphones Mijk at the respective positions C, D, A and B.
  • Fig. 7 shows a configuration wherein the known TDOA ranging is applied.
  • Fig. 7 shows the same configuration as in Fig. 5.
  • the sound emitted by the loudspeaker LSi at the position X is received by the microphones Mijk at the positions J, K, L and M belonging to a neighbouring processing system Q.
  • the processing system Q has no accurate information on when the processing system P emitted the sound, only the time differences of arrival of this sound at the microphones J, K, L and M can be measured. In the absence of the further interpretation according to this invention, these difference
  • Fig. 8 shows signals of the TDOA ranging configuration of Fig. 7.
  • the instant Tx at which the loudspeaker LSi at the positon X emits the sound is unknown to the processing system Q.
  • the times of arrival of this sound at the microphones Mijk at the positions J, K, L and M are indicated by RxJ, RxK, RxL and RxM, respectively.
  • the time difference between the instants RxJ and RxK is tdl2
  • the time difference between the instants Rxk and RxL is tdl3
  • the time difference between the instants RxL and RxM is tdl4.
  • the time difference toffset between the instants Tx and RxJ is unknown.
  • the difference measurement provided for use by the positioning algorithm comprises at least: the magnitude of the difference, in terms of either time or an equivalent quantity such as distance; the ID of the loudspeaker LSi that issued the sound; and the IDs of the two microphones Mijk at which the time-difference of arrival has been measured.
  • the time-differences are represented relative to an origin set at the moment the first signal that arrives is detected by a microphone Mijk. The first value is therefore zero and thus it is possible to define the moment of transmission as an event occurring in the past, according to the internal clock of the processing system Q.
  • This first value is related to the actual time of transmission by the time offset toffset, which is equal to the time taken for the sound to travel from the loudspeaker LSi controlled by the processing system P to this first microphone Mijk at the position J of the processing system Q.
  • This offset toffset is initially unknown, but if according to this invention its value is estimated, the difference measurements can easily be converted into an approximation of the range measurements and thus become the output values of the TOF ranging.
  • one of the time differences between the instant Tx and one of the instants RxK, RxL or RxM may be determined as being the common offset (the measured time differences may have a negative sign).
  • the estimated offset toffset has to be added to each one of the measured differences to create an approximation to time-of-flight, and hence calculate the equivalent range.
  • this offset toffset applies only to the set of measurements made of a single loudspeaker's sound probe. A separate estimate must be made on behalf of each neighbouring loudspeaker LSi.
  • Fig. 9 shows an example of a hypothesis tree.
  • the hypothesis tree HT has branches TPi and nodes Ni.
  • information from the hypothesis tree is used to derive an accurate estimate of the offset toffset between the difference measurements (TDOA) available and the range measurement (TOF) desired.
  • Each branch TPi of the tree HT represents a set of assignments of each microphone Mijk (thus: light source Lijk) to a location on the building plan BP.
  • Each node Ni on the tree HT represents a single possible assignment of one of the devices X, J, K, L, M (see Fig. 7) to a location.
  • the upper branch TPi assigns the devices X, J, K, L and M to positions 0, 1, 2, 3 and 4, respectively.
  • the interconnection lines BRi connect the successive nodes Ni in the branch TPi.
  • Each branch TPi contains a different set of possible assignments together with a probability value PVi calculated using optimised multilateration,
  • An important benefit of the tree HT is the way it provides many alternative contexts in which to interpret the measurements to/from each new device (microphone Mijk or loudspeaker LSi) as it is added to the tree HT. This avoids spreading sources of error throughout the entire collection of measurements, and allows us to seek consistencies between measurements and possible solutions that indicate the most likely interpretation of the data.
  • each branch TPi of the tree HT represents a proposed arrangement of devices X, J, K, L and M that can be helpful when estimating the offset value toffset according to the invention.
  • the measurements made between devices J, K, L and M can be compared with the actual distances between the locations to which they have been assigned. If it is assumed, for the purposes of extending this branch TPi, that these assignments are correct, the difference measurements have to be compared to the actual distances on the plan to see whether there is a match within the accuracy of the ranging technique.
  • this technique using the hypothesis tree HT converts time-difference of arrival (TDOA) measurements into time-of- flight (TOF) measurements by using geometrical information on the constellation of the loudspeakers LSi and microphones Mijk and thus the associated sensors Si and light sources Lijk. Equivalently, these time measurements can be viewed as distances, as these two quantities are related by the speed of propagation through a specific communication medium.
  • the sound emitted by the loudspeaker LSi at position X is received in a number of microphones Mijk at the respective positions J, K, L, M which are associated with devices such as for example lamps Lijk.
  • the received data in the processing system Q is a sequence of arrival times. This sequence of arrival times is denoted by the vector t wherein the sequence of the arrival times is in the order of the identification codes of the microphones Mijk that are known by the recording device Q in the figure:
  • the vector d now consists of time-differences of arrival relative to the kt microphone Mijk.
  • the correct distances from X to all the microphones Mijk are known from the building plan BP.
  • the commissioning problem is that the orderings of the microphone identification codes and the orderings of the devices (for example the lamps Lijk associated with the microphones Mijk) marked in the building plan BP are different and the mapping between these orderings is unknown.
  • the permutation matrix is a binary matrix of which each column and row has only one 1 and the rest of the elements are zeros.
  • the number of possible permutations (or different matrices, P) is N ⁇ , wherein N is the number of devices. For example, already with ten devices the number of possible permutations more than 3.6 million, In addition, the value of is unknown.
  • the distances known from the building plan BP are used to approximate the unknown offset value r ⁇
  • an efficient method based on hypothesis trees is used to solve the permutation problem.
  • it is assumed that is started with r 3 ⁇ 4 where 3 ⁇ 4 is the shortest distance in r and then find the permutation P that minimizes the cost function.
  • the time-difference of arrival measurements are converted to estimates of true time-of- flight estimates relative to the position of X.
  • the information from the hypothesis tree HT is used to select the most likely candidate for 3 ⁇ 4 .
  • This embodiment applies background information which can be extracted from other sources of available information relating to a particular application of interest, such as for example the building plan BP. Other applications may provide similar opportunities to extract equivalent information.
  • this embodiment features a hypothesis tree HT that allows to experiment with various values of the offset toffset (in time domain) or r (in space domain) that are customised to the particular circumstances in which they are being applied.
  • the present invention makes a useful estimate of a range by applying this offset to measured time-differences. It was found that even although the quality of the offset estimate affects the results, even a course estimate produces useful results.
  • FIG. 5 which comprises the lights Lijk or microphones Mijk at the positions A, B, C and D and the PIR-sensor Si or loudspeaker LSi at the position X, for example by using the standard time-of- flight techniques.
  • the PIR-sensor Si at the position X is therefore identified, or at least a believable hypothesis for that assignment exist which is used as the basis for positioning the group on the right (the lights Lijk or microphones Mijk at the positions J, K, L, M and the PIR -sensor Si or loudspeaker LSi at the position Y). Because there is no wired audio connection between the loudspeaker LSi at position X and the microphones Mijk associated with the lights Lijk at the positions J, K, L and M, time-difference of arrival techniques are employed.
  • references J, K, L, M may be used to indicate the positions, the lights Lijk or the microphones Mijk and that the reference X may be used to indicate the position, the sensor Si or the loudspeaker LSi.
  • Fig. 10 shows an example of how to find the required position.
  • Fig. 10 shows the same configuration as is shown in Fig. 7.
  • the distance between the position X at which the loudspeaker X is arranged and the position J at which a microphone J is arranged is rol .
  • the distance between the position X and the position K at which a microphone K is arranged is ro2.
  • the distance between the position X and the position L at which a microphone L is arranged is ro3.
  • the distance between the position X and the position M at which a microphone M is arranged is ro4.
  • the difference measurement between the microphones J and K is dl2.
  • the time difference with which the sound emitted by the loudspeaker X reaches the microphones J and K is tl2 which multiplied by the speed of sound leads to a difference distance dl2.
  • the different measurement between the microphones J and L is dl3 and the difference measurement between the microphones J and M is dl4.
  • the task is to assign the network IDs used for routing control messages to the locations as might be indicated on a building plan BP.
  • the hypotheses tree approach allows creating a hypothesis for each possible assignment, leaving the final decision for a later stage, when further information will have been made available. Knowing the difference measurement dl2 between J and K, the tree HT has four first-level hypotheses assigning ID1 to each of lights J, K, L and M. So far there is little indication which of these first-level hypotheses is correct. It is possible that the relative magnitude of the difference values might provide a clue, for example light J is expected to be closer than light K. However, all the measurements are subject to error, and it may not be possible to clearly distinguish between the measurements available.
  • r04 r01 + dl4
  • Bxj is the actual distance between devices X and J, as shown on the building plan BP. This provides the required conversion from hyperbolic differences measurements to circular estimated ranges.
  • Fig. 10 shows the estimated r02 being applied in combination with ranges (or estimated) ranges from other devices to find the position of ID2 using multilateration, or similar. Because this position agrees well with the expected position for one of the lights Lijk on the building plan, namely light K, we assign a high probability to the hypothesis that ID2 should be assigned light K.
  • a further enhancement is possible.
  • a greater number of actual distances is available upon which the calculation of the offset toffset or can be based, which can be used to average out the effect of measurement errors. For example, when working on level four we already have three assumed assignments available. Thus, three actual distances shown on the building plan, X to J, X to K and X to L can be compared with the differences dl2, and dl3.
  • this hypothesis tree approach discloses a technique to convert time-difference of arrival measurements into time-of- flight measurements, resulting in an "offset" value toffset or * 5 that is very easy to apply.
  • the approach shows how background information available from our main application of interest (the building plan) can be used to guide the estimation of the offset and that the hypothesis tree HT provides opportunities to achieve very highly accurate estimates of the offset.
  • multidimensional scaling is a technique that can be used to convert range measurements into a set of positions. This also requires spherical ranges as input rather than the hyperboloid differences that are available from time-difference of arrival measurements.
  • an estimate of the range corresponding to each difference value can be found by estimating the offset using some statistical properties of the building plan BP.
  • the shortest difference value (typically zero assuming the origin is chosen appropriately) is likely to correspond with shortest distances between devices shown on the plan BP. For example, it is very common for false ceilings in offices to be structured around a regular grid of ceiling tiles, which naturally spaces the devices at regular intervals, typically at multiples of 60 cm.
  • the best estimate of the typical offset may not necessarily be the very shortest distance shown on the plan. It may be better to seek the most common minimum separation between devices, using statistical techniques based on a histogram or a probability distribution function.
  • the installation technician could assess the minimum separation between devices that is typical for the current installation being conducted. This could be a simple visual assessment, made by counting the number of tiles separating neighbouring devices, or if necessary a tape measure could be used to take a sample of typical minimum distances. Success of this approach depends on the underlying accuracy of the time-difference measurement system and the sophistication of the
  • Fig. 11 shows an example using the Pythagorean relationship and the difference measurements.
  • rbd 2 2*reb*dbd + dbd 2
  • the present invention can be applied to any environment where speakers SPi and microphones Mijk are deployed, or equivalently, where radio transmitters, receivers or transceivers are deployed.
  • Applications are not limited to ceilings, as switches SWi, sensors Si and light sources Lijk can be placed anywhere within a building or in an outside environment. Neither is it limited to lighting installations, as any installation of loudspeakers LSi and microphones Mijk (or radio transceivers) could benefit from this technique.
  • mobile devices may utilise signals transmitted to or from lighting devices on the ceiling.
  • a mobile device held at approximately hip height, or desktop height, in a room with 3 m high ceilings can be assumed to have an offset of roughly 2 m from the nearest lighting device. This estimated offset can be used to place the mobile device using a single sound received by several microphones associated with respective lighting devices.
  • This invention allows multilateration or multidimensional scaling techniques to be applied without the complication of hyperbolic calculations.
  • radio frequency signals could be employed, as they were in the LORAN system.
  • Accurate radio frequency timings are anticipated to become practical soon, when the forthcoming ultra wideband (UWB) devices become available.
  • UWB ultra wideband
  • the latter are expected to offer time-of- flight ranging as standard, such as IEEE 802.15.4a, which would by default generate spherical range measurements directly, using the two-way ranging technique.
  • time-difference of arrival measurements can be used instead. This can greatly increase the capacity and utility of the services offered, and reduce the requirements for radio bandwidth, as many to a common transmission from the fixed infrastructure.
  • Use of the verb "comprise” and its conjugat exclude the presence of elements or steps other than those stated in a claim, "an” preceding an element does not exclude the presence of a plurality of su invention may be implemented by means of hardware comprising several di and by means of a suitably programmed computer.
  • the device claim enun means several of these means may be embodied by one and the same item c mere fact that certain measures are recited in mutually different dependent c indicate that a combination of these measures cannot be used to advantage.

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  • Physics & Mathematics (AREA)
  • Engineering & Computer Science (AREA)
  • General Physics & Mathematics (AREA)
  • Radar, Positioning & Navigation (AREA)
  • Remote Sensing (AREA)
  • Measurement Of Velocity Or Position Using Acoustic Or Ultrasonic Waves (AREA)

Abstract

La présente invention concerne un système de télémétrie comprenant un émetteur (T1) à une position d'émetteur (PT1) servant à émettre un signal d'émetteur (TS1) à un instant d'émetteur (tT1), un premier récepteur (R1) à une première position de récepteur (PR1) servant à indiquer un premier instant (t R1) où le signal d'émetteur (TS1) atteint le premier récepteur (R1), et un second récepteur (R2) à une seconde position de récepteur (PR2) servant à indiquer un second instant (t R2) où le signal d'émetteur (TS1) atteint le second récepteur (R2). Un calculateur (CAL) détermine une différence relative (t R12 ; dd12) entre le premier instant (t R1) et le second instant (t R2), et un estimateur (EST) est conçu pour estimer la différence absolue (t A11, t A12) entre l'instant d'émetteur (t T1) et le premier instant (t R1). Un estimateur (EST) reçoit la différence relative (t R12) et des informations géométriques (GI) définies par une propriété géométrique d'une configuration de l'émetteur (T1), du premier récepteur (R1) et du second récepteur (R2), pour obtenir une différence absolue estimée (t A11, t A12) entre l'instant d'émetteur (t T1) et le premier instant (t R1).
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Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2015104199A1 (fr) * 2014-01-07 2015-07-16 Koninklijke Philips N.V. Commande de balisage dans un système de positionnement
EP3203760A1 (fr) * 2016-02-08 2017-08-09 Thomson Licensing Procédé et appareil permettant de déterminer la position d'un certain nombre de hauts-parleurs dans une configuration d'un système ambiophonique
CN110926461A (zh) * 2019-10-29 2020-03-27 北京全路通信信号研究设计院集团有限公司 一种基于超宽带室内定位方法和系统、导航方法和系统

Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO1999021389A1 (fr) * 1997-10-21 1999-04-29 Telefonaktiebolaget Lm Ericsson (Publ) Subdivision intelligente de stations de base candidates pour la precision d'un releve de position
WO2002054100A2 (fr) * 2001-01-05 2002-07-11 Motorola, Inc., A Corporation Of The State Of Delaware Procede et dispositif d'estimation d'une position
WO2004019559A2 (fr) * 2002-08-20 2004-03-04 Bluesoft Ltd. Procede et systeme de recherche d'emplacements dans un reseau local sans fil
US20090045971A1 (en) 2006-03-06 2009-02-19 Koninklijke Philips Electronics N.V. Use of decision trees for automatic commissioning

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO1999021389A1 (fr) * 1997-10-21 1999-04-29 Telefonaktiebolaget Lm Ericsson (Publ) Subdivision intelligente de stations de base candidates pour la precision d'un releve de position
WO2002054100A2 (fr) * 2001-01-05 2002-07-11 Motorola, Inc., A Corporation Of The State Of Delaware Procede et dispositif d'estimation d'une position
WO2004019559A2 (fr) * 2002-08-20 2004-03-04 Bluesoft Ltd. Procede et systeme de recherche d'emplacements dans un reseau local sans fil
US20090045971A1 (en) 2006-03-06 2009-02-19 Koninklijke Philips Electronics N.V. Use of decision trees for automatic commissioning

Cited By (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2015104199A1 (fr) * 2014-01-07 2015-07-16 Koninklijke Philips N.V. Commande de balisage dans un système de positionnement
US9838993B2 (en) 2014-01-07 2017-12-05 Philips Lighting Holding B.V. Controlling beaconing in a positioning system
EP3092858B1 (fr) 2014-01-07 2018-12-26 Philips Lighting Holding B.V. Commande de balisage dans un système de positionnement
EP3092858B2 (fr) † 2014-01-07 2022-05-04 Signify Holding B.V. Commande de balisage dans un système de positionnement
EP3203760A1 (fr) * 2016-02-08 2017-08-09 Thomson Licensing Procédé et appareil permettant de déterminer la position d'un certain nombre de hauts-parleurs dans une configuration d'un système ambiophonique
CN110926461A (zh) * 2019-10-29 2020-03-27 北京全路通信信号研究设计院集团有限公司 一种基于超宽带室内定位方法和系统、导航方法和系统
CN110926461B (zh) * 2019-10-29 2022-04-12 北京全路通信信号研究设计院集团有限公司 一种基于超宽带室内定位方法和系统、导航方法和系统

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