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    • 专利摘要:
    A method (100) and apparatus for dynamically modifying (140) a database for use in locating an object has been described. The method comprises determining whether an estimated location corresponds to an obtained location profile of the object, and if not, dynamically adjusting the database to display a signal space on a physical space.
    公开号:BE1020062A5
    申请号:E2011/0433
    申请日:2011-07-08
    公开日:2013-04-02
    发明作者:Maarten Weyn
    申请人:Univ Antwerpen；Artesis Hogeschool Antwerpen；
    IPC主号:
    专利说明:

    Methods and devices for adjusting object localization
    Field of application of the invention
    The invention relates to the domain of object localization. More specifically, the present invention is related to a method and an apparatus for dynamically adjusting the mapping of a signal space of a set of transmitters used to locate objects.
    /
    BACKGROUND OF THE INVENTION
    Localization using signal receivers and / or signal transmitters, for example localization using a fingerprint of the RF signal strength to determine the location of an object, is widely spread.
    Typically, for obtaining accurate results, an off-line phase is performed in which manual calibration of various points with a known location is performed to calibrate the localization system.
    This calibration results in a database of fingerprints that stores the recorded signal strength of the points with known location. In a second phase, the database is used to compare the signal strength that is recorded, for example, by the object being traced with the fingerprint database.
    Signal strengths are very dynamic and can be influenced by, for example, doors that are opened or closed, furniture that has been moved, people passing by, external RF sources, environmental conditions, etc. Because the current fingerprint can therefore differ from the fingerprint that is in the database stored, this will result in an inaccurate estimate of the location of the pattern. A number of suggestions were made to overcome this inaccuracy.
    In a first suggestion, the recalibration of the entire environment is performed manually, each time a change in the RF environment has occurred. It was determined that this is feasible to deal with major changes, for example when the infrastructure has been changed, provided that the change has been signaled to the administrator of the system, but that this is not feasible with minor changes. Manually recalibrating the entire environment results in an enormous manual interaction and does not seem feasible to deal with short-term fluctuations.
    In another suggestion, static reference measurement points are provided that allow recalibration, for example at predetermined time intervals. By using static reference measurement points, the signal strength is measured at various known locations. Change in signal strength can be used to dynamically adjust the fingerprint database. Such a system only works on the condition that the static / fixed reference points are not changed in location, for example, is not subject to shift.
    In addition, this requires the provision of static / fixed reference points that must be fed. An example of such a recalibration system is described in US6380894, where geo-location errors associated with variations in signal transport path parameters are effectively removed by installing one or more reference labels, whose geo-locations are precise be known. The signal sent by the reference labels is processed and is coupled to the geo-location processor. Comparison allows you to adjust the recalibration based on these reference labels. Another example of this is described in WO2009 / 072735, in which a system for analyzing the environment is used and where explicit communication between the access point and a receiving terminal is provided.
    In yet another suggestion, use is made of a plurality of additional sensors for measuring changing conditions, such as, for example, when doors are opened or closed, or when the humidity or temperature changes. This information can then be used to recalibrate the system. Such recalibration is limited in the number of aspects that can be taken into account for the change in the fingerprint and requires the provision and feeding of sensors. Associated with this is the recalibration by selecting a fingerprint selected from a set of fingerprints, for example recorded at different times during the day and thus taking into account varying conditions of the signal path during the day. An example of the selection of a fingerprint from a set of predefined fingerprints, the selection depending on current conditions is described in US2003 / 008668.
    Recalibration, using for example the previous techniques, can be based on input from a user, who indicates that the estimated position is wrong. This requires user interaction to indicate to the system where the user is located. There is room for a more efficient way of recalibrating a localization system.
    Summary of the invention
    It is an object of embodiments of the present invention to provide good methods and apparatus for recalibrating localization systems, as well as to provide localization systems thus obtained.
    It is an advantage of embodiments of the present invention that manual interaction required for recalibrating the system can be reduced or even avoided. It is an advantage of embodiments according to the present invention that the recalibration can be performed automatically if required, without user intervention. ,
    It is an advantage of embodiments according to the present invention that the recalibration for adjusting the display of a signal space on a physical space can be performed in an automatic process by using the location profile of the user.
    It is an advantage of embodiments according to the present invention that the recalibration can be performed without the need for additional components that must be placed and fed in the environment where localization is to be performed.
    It is an advantage of embodiments of the present invention that no reference points are required for recalibration. It is thus an advantage of some embodiments of the present invention that no additional equipment is required.
    It is an advantage of embodiments according to the present invention that the recalibration can be performed taking into account short-term fluctuations as well as long-term fluctuations.
    It is an advantage of embodiments according to the present invention that all aspects that induce an environmental change, and thus induce a modified fingerprint, can be taken into consideration, such as, for example, the presence of people, changed environmental radiation fields, changed setting, etc. It is an advantage of embodiments according to the present invention that the recalibration can be performed in an automated and / or automatic manner, without requiring user interaction.
    The above object is achieved by a method and apparatus according to the present invention.
    The present invention relates to a method for dynamically modifying a database for displaying a signal space on a physical space of a set of access points for use in locating an object. The method comprises obtaining a location profile of the object, obtaining an estimated location of the object by measuring the signal parameter induced by at least one access point and by using the database to display a signal space on a physical space for deriving an approximate location of the measured signal parameter. The method further includes determining whether the estimated location matches the obtained location profile of the object, and if the obtained estimated location does not match the location profile, dynamically adapting the database for mapping to a modified database for mapping obtain a signal space on a physical space.
    It is an advantage of at least a number of embodiments according to the present invention that the recalibration of a system, using the imaging of a signal space, can be used to compensate for dynamic changes in the environment, without requiring user intervention, for example in an automated and automatic manner.
    It is an advantage of at least a number of embodiments according to the present invention that the recalibration of a system, using the imaging of a signal space, can be used to compensate for dynamic changes in the environment, without the need for external sensors. must position or without the need for significant amounts of hardware components.
    It is hereby an advantage that fewer feeding stations have to be provided for feeding such components. It is an advantage of at least a number of embodiments according to the present invention that the recalibration of a system, using the imaging of a signal space, can be used to compensate for dynamic changes in the environment, wherein the configuration for recalibration may deviate from preset configurations for recalibration so that it can compensate for real dynamic changes.
    It is an advantage of embodiments according to the present invention that the recalibration can lead to more accurate data from all access points.
    Obtaining a location profile of the object may include obtaining a location profile for the object, the location profile being based on a plurality of location determinations of the object, using the database for mapping a signal space to a physical space.
    It is an advantage of some embodiments of the present invention that an object's behavior can be easily derived, and that this information can be used to automatically adjust dynamic changes in the environment.
    The method may include determining a newly estimated location of the object, using the adapted database to display a signal space on a physical space.
    It is an advantage of some embodiments of the present invention that an immediate accurate mapping of the signal space can be used because the calibration can be performed at the time the dynamic change occurs.
    The method may include repeating whether the obtained estimated location corresponds to the obtained location profile of the object, dynamically adjusting and determining the newly estimated location, until the obtained estimated location matches the obtained location profile.
    It is an advantage of some embodiments of the present invention that a predefined threshold value can be set above which recalibration can be performed.
    In addition, prior to a dynamic adjustment, the method may include the evaluation of the adequacy of the location profile. The location profile can be updated depending on this evaluation.
    The method may include determining whether or not a sudden change in a signal parameter occurs for a plurality of transmitters and / or receivers. It is an advantage of some embodiments of the present invention that a sudden change in signal parameter can trigger recalibration, resulting in a rapid adjustment after a change in environment.
    The method may include determining whether or not the object, during a certain time interval, is usually located at a recent conventional location different from a traditional conventional location based on the location profile. The usual location can be the location where the object is located for most of the time. It is an advantage of embodiments according to the present invention that the recalibration can be triggered by a sudden change of the usual position.
    The dynamic adjustment may include determining a modified database for mapping a signal space to a physical space based on the differences between the measured signal parameter and the signal parameter corresponding to the signal space for the expected position based on the location profile. It is an advantage of some embodiments of the present invention that rapid convergence to an accurate database for displaying signal space to physical space can be achieved after a dynamic change in the environment.
    Dynamically adjusting the display to obtain a modified database for displaying a signal space into a physical space may include determining the modified database for displaying a signal space on a physical space based on unlikely positions of the object. It is an advantage of some embodiments of the present invention that improbable results and obvious errors are automatically corrected.
    The database for mapping a signal space to a physical space can be any of the following databases: an RF fingerprint database or a database of base station locations. It is an advantage of some embodiments of the present invention that this can be applied in a domain of RF localization. It is an advantage of some embodiments of the present invention that the method and system can be implemented in a quick and simple manner, for example by installing an additional software component in a processing unit of the RF localization system. It is an advantage of some embodiments of the present invention that the system can be easily upgraded to a system that provides automatic recalibration according to embodiments of the present invention.
    The set of access points can be a selected set of access points, selected on the basis of their spatial configuration.
    The dynamic adjustment can be performed if the expected location does not match the location profile for at least a predetermined number of times.
    The dynamic adjustment can be performed if, for at least a predetermined number of access points, a difference is detected between the measured signal parameter and the signal parameter corresponding to the signal space for the location that is expected based on the location profile.
    The present invention also relates to an apparatus for dynamically modifying the database for displaying a signal space to a physical space of a set of access points for use in locating an object. This device comprises an input means for receiving a location profile of the object and for receiving a measured signal strength induced by at least one access point. The apparatus comprises a processing unit for deriving an approximate location of an object, based on the signal parameter, using the database for mapping a signal space to a physical space. The processing unit is furthermore adapted to determine whether the estimated location corresponds to the obtained location profile of the object and, if the estimated location does not match the location profile, to dynamically adapt the database for display to a modified database for displaying to obtain a signal space on a physical space.
    The adjustment may be based on a difference between the measured signal parameter and the signal parameter corresponding to the signal space for the location expected based on the location profile.
    The device can be a control device that can be used in an object location system.
    The device can be executed as a computer program product for, if it is executed on a computer, performing the dynamic adjustment of displaying a signal space of a set of transmitters and / or receivers for locating an object.
    The present invention also relates to a computer program product for - when executed on a computer - performing a method for dynamically adjusting the image of the signal space of a set of transmitters and / or receivers for locating an object according to above methods.
    The present invention also relates to a machine-readable data storage device on which the computer program product is stored as described above and is also related to transmission of such a computer program product over a local or wide telecommunications network.
    The present invention also relates to a method for upgrading a localization system. The method comprises installing a computer program product as described above on a processing unit of the localization system or installing a device as described above.
    Specific and preferred aspects of the invention are included in the appended independent and dependent claims. Features of the dependent claims can be combined with features of the independent claims and with features of other dependent claims as appropriate and not merely as explicitly stated in the claims.
    These and other aspects of the invention will be apparent from and elucidated with reference to the embodiments described below.
    BRIEF DESCRIPTION OF THE FIGURES FIG. 1 illustrates a schematic overview of a method for dynamic adaptation of displaying a signal space of a set of access points, according to an embodiment of the present invention.
    FIG. 2A and FIG. 2B show a schematic representation of the general process for locating an object and recalibrating the image of a signal space into a physical space, the recalibration being performed according to an embodiment of the present invention. FIG. 2A illustrates an example of an initialization process and FIG. 2B illustrates an example of a process for mapping.
    FIG. 3 illustrates a schematic representation of an irregular process for imaging, as may be used in an embodiment of the present invention. FIG. 4A shows an example of a localization system that can use an apparatus for adjusting the display of a signal space to physical space of a set of access points, according to an embodiment of the present invention. FIG. 4B shows an example of an apparatus for dynamic adaptation of displaying a signal space to a physical space for a set of access points, according to an embodiment of the present invention.
    FIG. 5 illustrates a processing means that can be used to perform a method according to an embodiment of the present invention.
    FIG. 6 illustrates a graphical representation of a fingerprint for a single access point as may be used in methods and systems according to embodiments of the present invention. FIG. 7 illustrates an example of a location profile such as can be used according to an embodiment of the present invention.
    FIG. 8 illustrates an example of a modification of the mapping, using a method according to an embodiment of the present invention.
    FIG. 9 illustrates an experimental result of monitoring, on the one hand, a method that uses dynamic recalibration according to an embodiment of the present invention and, on the other hand, a method without recalibration.
    FIG. 10 illustrates an experimental arrangement for dynamic recalibration in an office environment, showing details and advantages of an embodiment of the present invention.
    FIG. 11 illustrates the obtained location error, using a dynamic recalibration method according to an embodiment of the present invention, for an arrangement as shown in FIG. 10.
    FIG. 12 illustrates the obtained location error with dynamic recalibration in a home environment, showing details and advantages of an embodiment of the present invention. FIG. 13 illustrates the estimated location behavior profile of a test object, showing details and advantages of an embodiment of the present invention.
    FIG. 14 illustrates - for an experimental arrangement - the adaptation of a fingerprint for a newly added access point when using a method according to an embodiment of the present invention.
    FIG. 15 illustrates - for an experimental arrangement - the modification of a fingerprint for a remote access point when a method is used according to an embodiment of the present invention.
    The figures are only schematic and non-limiting. In the figures, the dimensions of some parts may be exaggerated and not represented to scale for illustrative purposes. Reference numbers in the claims may not be interpreted to limit the scope of protection. In the various figures, the same reference numbers refer to the same or similar elements.
    Detailed description of illustrative embodiments
    While the invention will be illustrated and described in detail in the figures, such illustrations and descriptions are to be regarded as illustrative or exemplary and not limitative. The invention is not limited to the described embodiments. Other variations on the described embodiments can be understood and carried out by those skilled in the art by carrying out the claimed invention, by studying the figures, the description and the claims described.
    In the claims, the term "include" does not exclude that there are other elements or steps, and the indefinite article "a" does not exclude that there are multiple elements or steps. A single processing unit or other unit can provide the functionality with a plurality of elements described in the claims.
    The fact that certain measures are mentioned in mutually distinct dependent claims does not mean that a combination of these measures cannot be used advantageously.
    A computer program can be stored or distributed on a suitable medium, such as an optical storage medium or a solid medium, supplied together with or as part of other hardware, but can also be distributed in other forms, such as for example via the Internet or via other wired or wireless telecommunication systems.
    The current description provides details of certain embodiments of the invention. It will be understood, however, that no matter how detailed the foregoing may appear in text, the invention can be applied in many ways. It should be noted that the use of particular terminology in describing certain features or aspects of the invention should not be construed to imply that the terminology is redefined herein to be limited to specific features of the features or aspects of the invention with which this terminology is linked.
    Where in the embodiments according to the present invention reference is made to an object or to an object to be traced or to an object to be traced, reference is made to the device to be traced or to the user who carries such an device. Such an object can be a wireless element, such as for example a receiver / transmitter or a device which comprises such a receiver / transmitter, such as for example a mobile telephone or computer, PDA or a label, etc.
    Where in embodiments according to the present invention reference is made to access points, reference is made to devices that emit / emit / receive electromagnetic radiation. Both the access points and the tracing principle can use different types of technology, such as, for example, WiFi technology, wireless network technology, ultra broadband wireless communication, Zigbee, Bluetooth, or generally any RF technology, visual sensor techniques, sound and ultrasonic technology. , radiation technology such as laser or IR, etc.
    Where in embodiments of the present invention reference is made to signal space, reference is made to the mathematical space in which for each location the signal parameter of the signals induced by the access points is given. Reference may be made, for example, to the mathematical space in which for each location the signal strength of the signals transmitted by or to the access points is known, or where for each location the time is required for signals to move between the object and the access point or vice versa, or the angle from which the radiation is emitted or to where the radiation is emitted.
    Where in embodiments of the present invention reference is made to signal parameters, this may refer to signal strength, beam angle, signal travel time or related time differences, etc.
    Where in embodiments according to the present invention reference is made to the estimated location, reference is made to the location as determined based on the measurement of the signal parameter, e.g. the signal strength, the angle of the radiation emission, the time required for the radiation to be received, or the related time difference, and this, derived by using the image database. This location can typically differ from the current location and a correction is required for this. Where in embodiments of the present invention reference is made to "recent usual location", this may refer to the location occupied by the object to be traced, according to two or more recent traces. Where in embodiments according to the present invention reference is made to "classically usual location based on the location profile", reference is made to the location typically occupied by the object to be traced according to the location profile.
    In a first aspect, the present invention relates to a method for dynamically modifying or modifying a database for displaying a signal space on a physical space for a set of access points used in a method for locating an object. The method can advantageously be used, for example, in systems in which localization of an object is carried out by using a set of access points that send out signals and when evaluating the display of a signal space on a physical space of a set of access points, e.g. fingerprints . As indicated above, this method is not limited to RF applications, but can also be used for a variety of applications, based on different signal transport properties, such as laser or IR radiation, sound and visual sensor techniques, etc.
    The method according to the embodiments of the present invention allows a correction of a change in the display of a signal space on a physical space, for example by changing the environmental conditions, change in the physical position of objects in the area of interest, etc.
    By way of example, where embodiments of the present invention are not limited thereto, a method according to an embodiment of the present invention will be described with reference to FIG. The method 100 according to embodiments of the present invention comprises obtaining 110 a location profile for an object. For example, the location profile may contain details regarding the location of the object or the evolution of the location of the object as a function of time. The location profile can be obtained, for example, by data mining of the data already determined with the location system, although embodiments are not limited thereto.
    In one example, the location profile for the object can be based on multiple location determinations of the object, using a database for displaying a signal space on a physical space. The location profile can also be an input by the user. The location profile can contain the location pattern of the object, as well as the behavior of the object. Examples of location profiles can be found as follows: when a number of devices are traced, such as a laptop, pda, mobile device, tag, etc., some are temporarily fixed, such as for example a person working on his laptop at his desk. By data mining one can find the behavior of the device and / or of the user. For example, in the case of a laptop, a location profile may be the fact that the device is on average 90% of the time in a particular location, such as on a desk. The location profile can represent a statistical chance that an object is in a certain place, e.g. based on tracing over a certain time period. The location profile can take into account differences in behavior at different times in time, eg. different behavior at different times during the day or at different times during the week (eg weekend or working days).
    The location profile can be quantified, for example, by expressing it as a set of probabilities that an object to be traced is at a certain location during a certain time interval. The method 100 further includes obtaining an approximate location of an object 120 by measuring a signal parameter for an object 122, the signal parameter being induced by at least one access point of the set of access points and by using a database for mapping a signal space to a physical space to derive an estimated location from the measured signal parameter. Such a database may, for example, include the display of a signal space on a physical space that was recorded during the initial calibration procedure, for example by manual calibration or by the use of any suitable calibration technique. Typical examples of algorithms for efficiently obtaining information and the database for mapping can be, for example, deterministic or statistical algorithms. Alternatively, the database may be a modified version of an initial database, e.g. modified in an earlier step of recalibration. The database for displaying a signal space on a physical space can be, for example, an RF fingerprint database, a database of locations of base stations, or any other model that maps the signal space onto the physical space. Measuring the signal parameter can be performed, for example, by reading data from the object to be traced. The object can be adapted to receive data, i.e. a signal parameter or a parameter derived from the signal, based on induced signals, for example transmitted by one or more access points. The object can then be referred to as an active device. Alternatively, measuring a signal parameter can also be performed by capturing data from the access points, whereby the access points can be adjusted for the detection of a beacon signal of the object to be traced. The object to be traced can then be referred to as a passive device.
    The reading of the tracking device can be performed in any suitable way, embodiments of the present invention not limited to a particular way of reading. The data may contain information from the signal parameter, such as, for example, signal strength, emission angle, flight duration of signals, time difference, etc. In some embodiments, the data may be a fingerprint such as an RF fingerprint.
    The method also includes determining whether the obtained estimated location matches the obtained location profile of the object. Failure to match the obtained location profile may mean, for example, that the estimated position of one or more traced devices is suddenly located at a location close to their usual location, but not at their usual position for a long time. The difference between the measured signal from these traced devices and the signal in the image database can then be used to re-calibrate the image. Another example of non-correspondence is the prevention of a sudden change in the signal strength of one or more access points, which can be caused by, for example, a dynamic disturbance. Yet another example of non-correspondence is the occurrence of objects in unusual places, such as too close to a wall, tending to go through walls, or the occurrence of many objects in unusual rooms, etc.
    In one example, the method may include determining whether the object is in a predefined time interval, usually positioned at a recent, conventional location that is different from a traditional, conventional location based on the location profile. The conformity can be evaluated based on a conformity score. Such a score can, for example, be based on the probability that, according to the location profile, an estimated position will occur for an object to be traced, etc.
    In addition, if the obtained estimated location does not match the location profile, the method includes dynamically adjusting 140 the mapping of the signal space to the physical space to obtain a modified database for mapping the signal space to physical space. The latter may, for example, be based on a difference between a measured signal parameter and the signal parameter that corresponds to the signal space for the expected location expected based on the location profile.
    The different steps can be repeated until a good agreement is reached between the estimated location and the location profile. The latter can be evaluated by determining whether the difference between the estimated location and the expected location based on the location profile is smaller than a certain value. In other words, the method may include determining a new approximate location of the object that utilizes custom mapping of the signal space to the physical space. In a number of embodiments, in addition to being an intermediary step, it can be evaluated whether the location profile is still accurate and if it is judged that this is not the case, an optional adjustment of the location profile 160 can be performed.
    Embodiments of the present invention result in an automated and / or automatic method for recalibrating a localization system, and therefore in an improved localization system and the results obtained therewith. The recalibration procedure as described above can be performed continuously, at predetermined time intervals, when preselected objects to be traced are located, etc. In some embodiments, the selection of the object to be traced may be used for recalibration automatically based on various parameters, such as the integrity of the behavioral profile, the spatial distribution, the calculation capacity, etc.
    By way of illustration, embodiments of the present invention are not limited thereby, an example of a recalibration method is described in combination with a localization method that can benefit from it, with reference to FIG. 2A and FIG. 2B. Standard and optional steps of the recalibration method are discussed, as well as steps that are part of the localization method. The exemplary process 200 as shown in FIG. 2A and FIG. 2B shows a method for the localization of an object to be traced in combination with a method for re-calibration. FIG. 2A here illustrates an initialization process in which a behavioral profile can be constructed and FIG. 2B illustrates the process for mapping. Detection can typically be based on evaluating the signal parameter measured in an object to be traced and induced by at least one but preferably by a set of access points.
    In FIG. 2A, an initialization process is illustrated in which a behavioral profile can be constructed. The initialization process can use the following steps:
    Using an incoming measurement of the object to be traced, which indicates a signal parameter induced by at least one access point and using the existing database to display a signal space on a physical space, the location machine estimates the location. Such a location estimate can be performed by the localization machine 206 based on a signal parameter measurement 202 and using the database for displaying 204. The localization machine 206 provides an estimated position 208 as output.
    The estimated position 208 is used to generate a location profile 210 of the object to be traced. Such a location profile 210 may, for example, provide information regarding the dynamics of the position of the object to be traced. An example of how a location profile can be constructed can be based on the probability that an object d to be traced is located at a location / during a time interval t. Such a probability can be estimated as:
    [1]
    A location profile of a device for a time period can then be described by dividing the time period into η intervals and is given by:
    [2]
    The location profile is typically constructed by tracing an object over a long time and can therefore be registered in advance or can be a continuously updated data source.
    in FIG. 2B, the full arrows in the full process example describe a possible suggestion for a standard location and an irregular detection process. Similar to setting up a location behavior profile, the method includes the use of an incoming measurement of the object to be traced. The incoming measurement is indicative of a signal parameter induced by at least one access point. The method also includes the use of an external or non-external database for displaying a signal space on a physical space for estimating a position. Such a position estimate can be performed by a localization machine 206 based on a signal parameter measurement 202 and by using the mapping database 204. The localization machine 206 provides an estimated location 208 as input.
    The procedure 200 indicated in FIG. 2B further comprises comparing the estimated location 208 with the location profile 210 to detect whether there is an irregular location. The latter is indicated by decision step 216 in the procedure 200. An example of the detection of a local irregularity is detection by statistical analysis whether the estimated location is irregular.
    When considering the location profile and the probability that an object is on a certain plate, an irregularity score, for example, can be defined as follows:
    [3]
    behavioral irregularity limit value [4] and if the score for the behavior of the irregularity exceeds a predefined limit value, also called threshold value, the location is treated as a possible irregularity.
    The threshold value can depend on the probability distribution and can be initialized as
    [5]
    If the derived estimated location 208 does not correspond to the location profile 210 and if it is decided in step 216 that this is related to an irregular behavior, this will be treated, according to the present example, by an irregularity procedure for mapping 214. Alternatively, it may be decided that the location profile must be adjusted. The latter can be decided because an object to be traced has developed a new behavior, whereby, for example, new locations that are visited are not yet present in the location profile but are valid estimated positions.
    The irregularity procedure for mapping 214 examines whether the absurdity may have been caused by an irregularity in mapping based on a comparison between the recorded measurement and the database for mapping. If a possible irregularity for the mapping is detected, an adjustment is estimated 218 and applied to the mapping to be used in subsequent localization steps. Such an adjustment can be made provisionally and can be re-evaluated when future estimates of the position can be evaluated. In an example, the estimated position is compared with the data input corresponding to the most likely location near the estimated position. This corresponds to a local maximum in the location profile. The latter is referred to by the term expected position based on the location profile and this can be expressed as:
    [6]
    The sample Pearson correlation coefficient of the set (data input database for mapping, measurement) can be calculated sample Pearson correlation coefficient:
    May as standard score
    , if sample averagedX, e «^ if sample standard deviation: sx and if this coefficient exceeds a correlation threshold value: r> correlation limit value [8], the measurement will be further investigated. Otherwise, the measurement will be ignored and the new location will be added to the location profile.
    A possible evaluation of an irregularity procedure for imaging according to the exemplary procedure 200 can be as shown in FIG. 3. The irregularity in the mapping 302 is started with a step 304 where the most likely location in the location profile 210 is found that is in the vicinity of the estimated position 208. A correlation between the image and the measurement is determined by step 306 and an evaluation is made as to whether or not the correlation is above a certain threshold value in step 308. If this is not the case, the procedure is terminated in step 326.
    If the correlation is above a certain threshold value, an image data input is searched for that lowers the standard deviation for the difference between the image and the measurement to the very best value when the input is removed from the set. The latter is performed by finding an irregular data input for the image 310, calculating a standard deviation and calculating the difference for the possible sets 312 and evaluating whether or not the maximum standard deviation is above the threshold value 314.
    If this is not the case, the method is stopped. If the standard deviation is above a certain threshold value, it is evaluated whether a data input with a substantially smaller standard deviation can be determined in step 316. If this is the case, the data input is adjusted 318 to a limited set to correlate between the adjusted image and the increase the measurement 320. If the correlation is better than the original correlation according to step 322, an adjustment of the mapping is estimated.
    The procedure 200 described in FIG. 2B. also describes an optional feedback loop for finding a realistic adjustment. This loop is described by the procedure indicated by the dotted line. Starting from the estimated adjustment 218 and based on the current measurement 202, a new estimated position 208 is determined in the localization machine 206, using the adjusted image. This newly estimated position is again compared to the location profile 210 to see if the modification has initiated the anticipated improvement. If there is still an irregularity, the loop is repeated. The system may be programmed such that the loop is repeated until the distance between the estimated position and the expected position is less than the predetermined value and / or until a predetermined number of loops has passed. If there is no longer an irregularity, the adjustment is considered correct and the adjustment is processed to adjust the image database in step 220.
    In the procedure 200 shown in FIG. 2B, as in other embodiments according to the present invention, for example, the procedure can only select the most likely traceable objects for automatic recalibration, depending on their location profile or their spatial configuration. In another example, the system can only adjust the database for display after a predefined number of irregularities has been identified in successive steps. In yet another example, the system can only adjust the database for display after the same irregularities have been detected by at least a predefined number of access points.
    As indicated above, embodiments of the present invention are not limited by the specific manner in which the estimated location of an object is obtained by measuring a signal parameter induced by at least one access point. In a first specific embodiment, the object to be traced determines the signal parameter based on detection of a signal output from the access points. The signal parameter values can be sent to a processing unit or server by the object to be traced. In another embodiment, the object to be traced emits a beacon signal detected by the access points. Based on this detection, the access points evaluate the strength of the object to be traced and the data obtained can be sent to a processing unit or server.
    In one embodiment, the signal strength is used in direct connection with the angular determination. The depiction of the signal space on the physical space describes the position of access points and provides a description of how signal attenuation corresponds to the distance and optionally to the presence of objects that cause attenuation and signal attenuation on the trajectory.
    In a second aspect, the present invention relates to an apparatus for dynamically modifying a database for displaying a signal space on a physical space of a set of access points for use in locating an object. The device can be a part of a localization system or can be a separate device that works in combination with it.
    It may be provided as a processing unit or control unit with a localization system or it may be provided as an addition to a control unit with a localization system. The device can be used for and / or as part of a localization system as shown by way of example in FIG. 4A, which shows a localization system 400 for locating an object 404 using a set of access points 402.
    The access point 402 can be part of a localization system 400 or the localization system 400 can be used in combination with a set of access points 402.
    The access points 402 may be, for example, transmitters as described above, which emit radiation for which a signal parameter is to be measured by object 404. Localization of the object to be traced can be determined based on signal parameter values detected in the object in relation to the access points. The number of access points can be at least one, and is advantageously adjusted so that good coverage of the targeted area is obtained. Localization of an object to be traced can be performed by reading the signal parameter received at the object to be traced. This information is typically processed by a processing unit of the localization system 400, wherein the information of the object to be traced can be obtained, for example, in a wireless manner.
    A processor can typically evaluate the received or measured signal parameter values in the object to be traced, using an image of a signal space on a physical space, for example as a fingerprint of the access points, resulting in a position determination. As indicated above, according to embodiments of the present invention, the device can be part of such a localization system or can be used in combination with it.
    The device for dynamically adjusting the display, for example to handle a change in environment or setting, whereby the signal path of at least one of the access points to the object has been changed, comprises an input means for receiving the location profile for the object and for receiving a measured signal parameter induced by at least one access point from a set of access points.
    Receiving a measured signal parameter value induced by at least one access point can be performed in a similar manner to locating the object or can be obtained during localization.
    Receiving a location profile can be based on previously measured locations of the objects or can be entered by a user. The device can thus comprise a data input port and / or a measurement system for current determination of the input.
    It is advantageous that the location profile can be based on pre-measured locations. The device furthermore comprises a processing unit for deriving an estimated location of an object, using a database for displaying a signal space on the physical space. This part of the processing unit can be similar to the processing unit for localization or this part can be similar to the location component of the localization system.
    In addition, according to embodiments of the present invention, the processing unit is programmed to determine whether the obtained estimated location corresponds to the obtained location profile for the object and, if the obtained estimated location does not correspond to the location profile, dynamic adaptation of the database for displaying to obtain a modified database based on a difference between the measured signal parameter and the signal parameter corresponding to signal space for the location, expected based on the location profile.
    In addition, the device may contain components implemented as part of the processing unit or as a separate component, such as components adapted to perform the functionality of one or more of the functions as described in the steps of the system embodiments as described above.
    By way of illustration, not limitative of embodiments of the present invention, an example of an apparatus 450 for adjusting the display is shown in FIG. 4B. The device 450 comprises an input means 460 and a processing unit 470 as described above.
    Typically, a memory 480 for storing and retrieving information and an output means 490 for reporting data regarding the recalibration may also be present. The device can be adapted to perform distributed processing, ie part of the processing can be performed from a location, remote from the location where the object to be traced is located or remote from the location where the localization process processing happens processing is performed.
    The present invention therefore also relates to an apparatus having an input means for providing signal parameter information regarding the signal parameter measured in the object to be traced and a means for receiving location information obtained by a location system including an apparatus for adjusting the display as described above.
    The device can, according to embodiments of the present invention, be implemented as software on a calculation device or can be implemented as hardware. The device can be automatic or automated. Processing in the device may be based on a predefined algorithm, a set of instructions, a neural network, etc. Further benefits may be as set forth for other embodiments of the present invention.
    In one aspect, the device for adaptation as described in the second aspect can be provided as an application, which can be loaded into a processing unit of an existing localization system as an upgrade or which can be provided on a new localization system. It is an advantage of embodiments according to the present invention that a system can be upgraded to a localization calibration system with automated function, resulting in more accurate localization of traceable objects.
    Such an application can be provided in various ways, for example on a carrier or over a network, as will be described below. In one aspect, an adaptation device as described in a second aspect can be implemented as an additional module that can be incorporated into a localization system. In one aspect, embodiments of the present invention also include a method for upgrading a localization system, the method comprising installing an application as described above on the processor of a localization system or installing a processing module as described above the localization system.
    As already mentioned above, the methodical embodiments described above for dynamically modifying the image of a signal space from a set of access points to physical space access points for locating an object can be at least partially implemented in a processing system 500 as shown in FIG. 5.
    The systems as described above can also be implemented as processing systems, can be part of them or can comprise such a system. FIG. 5 shows a configuration of a processing system 500 that includes at least one programmable processing unit 503 connected to a memory subsystem 505 that contains at least one form of memory, such as, for example, RAM, ROM, etc.
    It should be noted that the processing unit 503 or the processing units may be for general use but may also be specific processing units. They may be adapted for incorporating into a device, such as, for example, a chip that has other components that perform other functions. Processing can be done in a distributed manner as well as in a single processing unit. Thus, one or more aspects of the present invention can be implemented in digital electronic circuits, or in computer hardware, specific business software, software, or in a combination thereof.
    The different steps can be computer-implemented steps.
    The processing system may include a storage subsystem 507 comprising at least a floppy disk drive, and / or a CD drive and / or a DVD drive. In some embodiments, a display device, a keyboard, and a pointing device may be included as part of a user interface subsystem 509 to allow a user to enter information manually.
    Gates for entering and reading data can also be provided. More elements, such as network connections, interfaces for various devices, etc., may be provided, but are not illustrated in FIG. 5. The memory of the memory subsystem 505 may at some point implement a part of or a complete (always shown as 501) set of instructions which, when executed on the processing system 500, implement the steps of the method embodiments described herein.
    An interconnection line 513 can be provided for connecting / connecting components. Although a general processing system 500 is well-known in the art, a system containing the instructions to implement aspects of the method of recalibrating a localization system in adjusting the mapping of a signal space to a physical space of access points for locating an object is not a prior art and, therefore, FIG. 5 is not labeled as prior art.
    The present invention also includes a computer program product that provides the functionality of any of the methods of the present invention when executed on a computing device. Such a computer program product can be contained in a carrier which contains a machine-readable code for execution by a programmable processing unit. The present invention thus also relates to a carrier that carries a computer program product which, when executed on a calculation means, provides instructions for performing any method as described above. The term "carrier" refers to any medium that contributes to providing instructions to a processor during processing. Such a medium can take many forms, such as, but not limited to, non-volatile media, and media for transmission. Non-volatile media include, for example, optical or magnetic discs, such as a storage means that is part of a mass storage. Common forms of computer-readable media include, a CD-ROM, a DVD, a flexible disk or floppy disk, a tape, a memory chip or cartridge, or any other medium that a computer can read. Various forms of computer readable media can be involved in carrying one or more sequences from one or more instructions to a processor for execution. The computer program product can also be sent using a carrier wave in a network, such as a LAN, a WAN or the internet. The sending media can take the form of a sound or light wave, such as those generated by radio waves or infrared data communication. Transmission / transmitting media include coaxial cables, copper wire, optical fiber, or wires from the interconnection line in a computer.
    In some embodiments, computer program products or systems such as those described above can be web applications, also referred to as web services, i.e. computer program applications that can be executed using a network such as, for example, a LAN, a WAN or the Internet. Part of the localization system, e.g. the access points and optionally also a part of the processing unit, can typically be located at a distance from the place where at least a part of the processing for the adaptation of the mapping is performed. The adaptation of the mapping can be provided as a web service, whereby a localization system is upgraded over a network.
    By way of illustration, some experimental results for using a method according to embodiments of the present invention are shown in FIG. 6 to FIG. 9. FIG. 6 illustrates a graphical representation of a fingerprint for a single access point as may be used in methods and systems according to embodiments of the present invention. The figure shows the signal strength h received in an object to be traced and transmitted in an access point. FIG. 7 illustrates an example of a location profile in which X and Y are coordinates of an environment, and wherein the figure thus indicates the probability that an object resides at a position (X, Y) based on the residence of an object at that position during the compile / prepare the location profile.
    FIG. 8 illustrates an example of an adjustment of the display, wherein a signal parameter is displayed as a function of the input for display, the solid lines indicating the original image, the dotted lines indicating the measurement, and the dashed lines indicating the adjusted image. It can be noted that the adjusted image provides a better image of the signal parameter than the original image.
    FIG. 9 illustrates an experimental result of tracing for a method of dynamic recalibration according to an embodiment of the present invention, as well as for an embodiment without a recalibration step. The error (expressed in m) as a function of the number of the measurement for successive measurements (i.e. equivalent to the measurement time) is shown. It can be noted that the method with dynamic recalibration provides much better results than the method without dynamic recalibration.
    Additional experimental examples are also discussed for illustration purposes. In a first additional example, the effect of the recalibration on the estimation of the location is illustrated. The experiment was conducted in an office environment, as shown in FIG.
    10. A person working on his / her laptop was used as a test object to measure the location error, this person is indicated by a circle in FIG. 10. Another person was working on a laptop at his / her desk in the neighboring office. This laptop was used for recalibration and is indicated with a small rectangle. The access points are indicated by triangles. Both laptops continuously send data to the localization machine. However, the machine was not yet able to construct a consistent location behavior profile of the first user (indicated by a circle). This means that only the measurements of the second user could be used to initiate adjustments to the display. The large rectangle indicates an area that was accessed by about 20 people. These people have strongly influenced the signal strength received from the three access points in this area. After the initialization process, the recalibration process could be used to adjust the fingerprint database. This resulted in an improved location estimate for the first user, as shown in FIG. 11, indicating that by using dynamic recalibration, the average 2D positioning error is significantly lower than without dynamic recalibration.
    In a second additional experiment, localization was performed in a home environment. The measurements were taken while working on the laptop in the room in the center of the house. Two localization machines were running simultaneously, one with automatic recalibration and one without automatic recalibration. The improvement is shown in the cumulative distribution function in FIG. 12. FIG. 13 illustrates the estimated location behavior profile of the test object.
    In a third additional experiment, the same setup as in the second experiment is used, with the only access point that was present inside the home test environment being removed and replaced with another access point. In the left room on the ground floor, the clients were still able to detect two very weak signals from neighbors' access points. In the rest of the area, only one access point from a neighbor was detected.
    In FIG. 14, the initial adjustment is shown for the fingerprint of this newly added access point. An initial adjustment estimates a signal strength of -56 dBm for this access point in the first room. This adjustment will spread to the other rooms as soon as the users move. The opposite adjustment is represented by automatically recalibrating for the deleted access point. This is shown in FIG. 15. Here, the process detects the removal of an access point due to the measurements of a user in the first room. This adjustment will again extend to the other rooms.
    权利要求:
    Claims (20)
    [1]
    A method (100) for dynamically modifying a database for displaying a signal space on a physical space of a set of access points (402) for use in locating an object (404), the method comprising the obtaining (110) a location profile of the object (404), wherein the location profile comprises a location pattern of an object, obtaining (120) an estimated location of the object (404) by measuring a signal parameter induced by at least one access point (402) and using the database to display a signal space on a physical space to derive an estimated location of the measured signal parameter, determining (130) whether the estimated location matches the obtained location profile of the object (404) by determining whether or not the object (404), during a certain time interval, is usually located at a recent usual location different from a classi A common location based on the location profile, and if the estimated location does not match the location profile, dynamically adapting (140) the database for mapping to a modified database for mapping a signal space to a physical space to become.
    [2]
    A method (100) according to claim 1, obtaining (110) a location profile of the object (404) comprising obtaining a location profile for the object based on a plurality of localization determinations of the object (404) using the database for displaying a signal space on a physical space.
    [3]
    A method (100) according to any one of the preceding claims, wherein the method (100) comprises determining a newly estimated location of the object, using the adapted database for displaying a signal space on a physical space.
    [4]
    A method (100) according to claim 3, wherein the method (100) comprises repeating determining (130) whether the obtained estimated location corresponds to the obtained location profile of the object (404), dynamically adjusting (140) and determining (120) the newly estimated location until the obtained estimated location matches the obtained location profile.
    [5]
    A method (100) according to any of the preceding claims, wherein the method (100), prior to a dynamic adjustment, includes evaluating (150) the adequacy of the location profile.
    [6]
    A method (100) according to the preceding claim, wherein the location profile is updated (160) depending on the evaluation.
    [7]
    A method (100) according to any one of the preceding claims, the method (100) comprising determining whether or not a sudden change in a signal parameter occurs for a plurality of transmitters and / or receivers.
    [8]
    A method (100) according to any one of the preceding claims, wherein the dynamic adjusting (140) comprises determining a modified database for mapping a signal space to a physical space based on the difference between the measured signal parameter and the signal parameter corresponding to the signal space for the expected position based on the location profile.
    [9]
    A method (100) according to any of the preceding claims, dynamically adjusting (140) the mapping to obtain a modified database for mapping a signal space to a physical space comprising determining the modified database for mapping of a signal space on a physical space based on unlikely positions of the object (404).
    [10]
    A method (100) according to any of the preceding claims, wherein the database for displaying a signal space to a physical space is one of an RF fingerprint database or a database of base station locations.
    [11]
    A method (100) according to any one of the preceding claims, wherein the set of access points (402) is a selected set of access points (402) selected on the basis of their spatial configuration.
    [12]
    A method (100) according to any of the preceding claims, wherein the dynamic adjustment (140) is performed if the expected location does not correspond to the location profile for at least a predetermined number of times.
    [13]
    A method (100) according to any of the preceding claims, wherein the dynamic adjustment (140) is performed if, for at least a predetermined number of access points, a difference is detected between the measured signal parameter and the signal parameter corresponding to the signal space for the location that is expected based on the location profile.
    [14]
    An apparatus (450) for dynamically modifying the database for displaying a signal space to a physical space of a set of access points for use in locating an object (404), the apparatus (450) comprising: - an input means (460) for receiving a location profile of the object (404) and for receiving a measured signal strength induced by at least one access point (402), wherein the location profile comprises a location pattern of an object and - a processing unit ( 470) for deriving from a signal parameter an estimated location of an object using the database for mapping a signal space to a physical space, the processing unit being further adapted to determine whether the obtained estimated location corresponds to the obtained location profile of the object (404) by determining whether or not the object (404) is usually located during a certain time interval erd is different at a recent usual location from a traditional usual location based on the location profile and for, if the obtained estimated location does not match the location profile, dynamically adapting the database for display to a modified database for display from a signal space to a physical space.
    [15]
    A device (450) according to claim 14, wherein the device (450) is a control device for use in an object location system (400).
    [16]
    A device (450) according to any of claims 14 to 15, wherein the device (450) is implemented as a computer program product for, if it is executed on a computer, performing the dynamic adjustment of displaying a signal space of a set of senders and / or receivers for locating an object.
    [17]
    A computer program product for, when executed on a computer, performing a method for dynamically adjusting the display of a signal space of a set of transmitters and / or receivers for the location of an object according to any of claims 1 to 13.
    [18]
    A machine-readable data storage device on which the computer program product according to claim 17 is stored.
    [19]
    A method for sending a computer program product according to claim 17 over a local or wide telecommunications network.
    [20]
    A method for upgrading a localization system, wherein the method comprises installing a computer program product according to claim 18 on a processing unit of the localization system, or installing an apparatus according to claims 14 to 16.
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    同族专利:
    公开号 | 公开日
    GB201011578D0|2010-08-25|
    GB2481851A|2012-01-11|
    EP2591378B1|2016-08-31|
    EP2591378A1|2013-05-15|
    ES2612474T3|2017-05-17|
    WO2012004420A1|2012-01-12|
    US20130116960A1|2013-05-09|
    US9606962B2|2017-03-28|
    引用文献:
    公开号 | 申请日 | 公开日 | 申请人 | 专利标题
    US20040203885A1|2002-11-25|2004-10-14|Geoffrey Quaid|Method and Radio Signature Position Determining Entity for maintaining location database reliability|
    US20100093368A1|2007-03-16|2010-04-15|Steffen Meyer|Device and Method for Localizing Terminal Devices|
    US6249252B1|1996-09-09|2001-06-19|Tracbeam Llc|Wireless location using multiple location estimators|
    US6380894B1|1999-08-30|2002-04-30|Wherenet Corporation|Multi-lateration system with automatic calibration and error removal|
    US6393294B1|1998-09-22|2002-05-21|Polaris Wireless, Inc.|Location determination using RF fingerprinting|
    US7421466B2|2001-10-29|2008-09-02|Hewlett-Packard Development Company, L.P.|Dynamic mapping of wireless network devices|
    US6839027B2|2002-11-15|2005-01-04|Microsoft Corporation|Location measurement process for radio-frequency badges employing path constraints|
    US7042391B2|2003-12-12|2006-05-09|Xerox Corporation|Mobile device and method for determining location of mobile device|
    US7359718B2|2004-04-30|2008-04-15|Hong Kong Applied Science And Technology Research Institute Co., Ltd.|Location determination and location tracking in wireless networks|
    CN101980550B|2004-10-29|2016-02-10|探空气球无线公司|The method of locating user devices|
    KR100848322B1|2006-12-08|2008-07-24|한국전자통신연구원|The system and method for indoor wireless location|
    KR100932271B1|2007-12-07|2009-12-16|한국전자통신연구원|Automatic Fingerprint Database Generation for Indoor Radiolocation|
    CN102077113B|2008-06-27|2014-03-26|弗劳恩霍夫应用研究促进协会|Device and method for allocating a current measurement value for a geographic position to a map object|
    US20100106745A1|2008-10-23|2010-04-29|Electronics And Telecommunications Research Institute|Method and apparatus for generating fingerprint database for wireless location|US8825388B2|2010-07-13|2014-09-02|Qualcomm Incorporated|Indoor likelihood heatmap|
    US20130267251A1|2012-04-10|2013-10-10|Qualcomm Incorporated|Personalized position using information correlation and self-sourcing|
    US8849188B2|2012-08-02|2014-09-30|Intel Corporation|Detecting sub-meter region of interest using radio signals|
    EP3109661B1|2013-06-14|2018-06-13|Indoo.rs GmbH|Method to create virtual reference points from radio fingerprints|
    EP3055707A1|2013-10-07|2016-08-17|Nokia Solutions and Networks GmbH & Co. KG|Determining information of objects|
    CN104635206B|2013-11-14|2018-10-23|中兴通讯股份有限公司|A kind of method and device of wireless location|
    CN104020443B|2014-05-23|2017-01-25|上海炫雅科技有限公司|Wireless positioning method based on wireless noise and system thereof|
    US9474042B1|2015-09-16|2016-10-18|Ivani, LLC|Detecting location within a network|
    WO2017050695A1|2015-09-21|2017-03-30|Philips Lighting Holding B.V.|Localization of a mobile device|
    JP6736412B2|2016-08-10|2020-08-05|三菱重工業株式会社|Target monitoring system and target monitoring method|
    US9900749B1|2016-12-12|2018-02-20|Here Global B.V.|Detection of infrastructure changes in opportunity signal data|
    EP3544323B1|2016-12-28|2021-02-17|Huawei Technologies Co., Ltd.|Method for determining channel delay, positioning method, and related device|
    US10421452B2|2017-03-06|2019-09-24|GM Global Technology Operations LLC|Soft track maintenance|
    JP2019091103A|2017-11-10|2019-06-13|東芝テック株式会社|Information provision apparatus and program|
    US10641610B1|2019-06-03|2020-05-05|Mapsted Corp.|Neural network—instantiated lightweight calibration of RSS fingerprint dataset|
    WO2022013128A1|2020-07-16|2022-01-20|Telecom Italia S.P.A.|Method and system for estimating an occupancy level of a geographic area|
    EP3951419A1|2020-08-05|2022-02-09|Nokia Technologies Oy|Apparatus comprising at least one processor|
    法律状态:
    2021-04-28| MM| Lapsed because of non-payment of the annual fee|Effective date: 20200731 |
    优先权:
    申请号 | 申请日 | 专利标题
    GB1011578.0A|GB2481851A|2010-07-09|2010-07-09|Object location|
    GB201011578|2010-07-09|EP11736033.9A| EP2591378B1|2010-07-09|2011-07-11|Methods and systems for adapting object locating|
    ES11736033.9T| ES2612474T3|2010-07-09|2011-07-11|Methods and systems to adapt the location of objects|
    PCT/EP2011/061789| WO2012004420A1|2010-07-09|2011-07-11|Methods and systems for adapting object locating|
    US13/808,990| US9606962B2|2010-07-09|2011-07-11|Methods and systems for adapting object locating|
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