Apparatus and method for measuring the length of a queue of people

Description

[0001] The present invention relates to an apparatus and a method for measuring the length of a queue of people having an entrance and a remote end.

[0002] The length of a queue is of interest to both those waiting in it and those moving towards the end of the queue, so that they can prepare for the waiting time and plan their daily tasks accordingly. The queue length is even more important for the operators of the facilities in front of which the queue forms, e.g. counters in a government agency or customer service office, airport gates, cash registers in a supermarket, entrances to an event venue, public transport stops, etc. Knowing the queue length allows them to decide, for example, whether additional counters, gates or entrances need to be opened or whether underutilized ones can be closed, or whether the processing speed of existing facilities should be increased or reduced, e.g. the frequency or capacity of public transport, etc., in order to achieve optimal utilization of the available facility without excessive waiting times.

[0003] Currently, queue length is measured using cameras, light barriers, ultrasonic or infrared sensors, foot switch mats, etc. All of these devices require complex on-site infrastructure, including appropriate cabling for power and data traffic.

[0004] The invention aims to create devices and methods for measuring the length of queues that require little infrastructure and can be used quickly and flexibly on site.

[0005] This object is achieved in a first aspect of the invention with a device of the type mentioned in the introduction, which according to the invention is characterized by: at least two data carriers arranged at different distances from the exit in the queue, each with a unique identifier that is machine-readable by a smart device of a waiting person and encodes the distance of this data carrier from the exit; a computing device with an interface via which it can receive identifiers that are machine-readable by smart devices and sent via a radio network; wherein the computing device is designed to select the greatest distance from all distances encoded by the identifiers received in a predetermined time window and to output this distance as the length of the queue.

[0006] The invention is based on a new technological approach to queue measurement by using smart devices carried by those waiting, e.g. smartphones, which can scan data carriers placed along the queue, for example in order to obtain information about the waiting time in the queue. The invention is based on the fact that almost everyone nowadays carries a smart device with them that can scan machine-readable identifiers such as QR codes, barcodes, NFC tags or the like, and on the information needs of those waiting, who scan the data carriers along the queue with their smart device. By querying the information from those waiting, a spatial image of the queue is statistically obtained over a time window, because those waiting usually only start scanning when they reach the end of the queue at the earliest.If, therefore, of the identifiers arriving in a given time window, each of which is queued for a (data carrier) location, only those with the greatest distance from the exit of the queue are taken into account, then the length of the queue is measured from the exit to its end - within the resolution limits of the distribution of the data carriers.

[0007] Preferably, the data carriers are arranged at approximately equal distances along the queue so that the length can be measured on a linear scale.

[0008] The size of the time window in which the identifier with the greatest exit distance is selected determines both the spatial and temporal resolution of the length measurement. If the time window is too short, no disk scans may arrive from the end of the queue, and the length measurement will be spatially inaccurate. A sufficiently long time window can ensure that at least one disk scan originates from the end of the queue. The spatial resolution of the length measurement is therefore higher the longer the time window. However, if the time window is too long, dynamic changes in the queue length, i.e. its growth and shrinkage over time, can no longer be adequately followed. The shorter the time window, the better the temporal resolution of the length measurement.

[0009] In a preferred embodiment of the invention, it is therefore provided that the time window is one tenth to ten times, preferably half to double, particularly preferably one time, the value ΔT opt = ΔL ⋅ D / SR + FR is, with ΔLaverage distance between two adjacent disks, Daverage number of people per unit length in the queue, FRRate of people approaching the end of the queue per unit time, SRRate of people leaving the exit of the queue per unit time.

[0010] This value represents an optimal compromise between spatial accuracy and timeliness of length measurement. Particularly practical designs are achieved in the preferred range between half and twice the optimum. The broader preferred range between one-tenth and ten times the optimum allows designs to be tailored to the desired requirements, whether with particularly high spatial accuracy or particularly high timeliness.

[0011] Attaching the data carrier(s) along the queue is an extremely simple and cost-effective process. For example, stickers can be used as data carriers, which can be optically read with a smart device's camera, or RFID or NFC tags, which can be read wirelessly using an RFID or NFC reader in the smart device. For the former option, each data carrier preferably carries its identifier in the form of a camera-readable QR code or barcode. Modern smartphones are often already equipped with a camera, so the invention can be used widely.

[0012] Preferably, the or each identifier also contains a web address of the computing device, so that those waiting can query data carrier-specific content, e.g. a data carrier location-specific waiting time, by simply calling up the web address in an Internet connection via the wireless network.

[0013] In front of event halls, in waiting areas of government offices, customer service centers, cash registers, markets, at airports, etc., queues are often delimited by belt stands, barrier posts, or the like. According to a particularly preferred embodiment of the invention, at least one data storage device is attached to such a belt stand or barrier post for the queue. On-site installation of the device according to the invention thus merely requires the installation of a detection device at the exit of the queue, a computing device connectable to this device and the smart devices of those waiting, and the installation of such belt stands or barrier posts equipped with data storage devices.

[0014] In meandering queues, some belt stands or barrier posts are used between two adjacent, oppositely traversed sections of the queue, meaning that people waiting pass such belt stands or barrier posts on both sides and in opposite directions. In this case, it is particularly advantageous if such a belt stand or barrier post is equipped with at least two data carriers pointing in different directions.

[0015] A special incentive that entices those waiting to scan the data carriers arranged along the queue is that, in a preferred embodiment of the invention, those waiting at each data carrier can determine their current waiting time at that location in the queue by scanning it. For this purpose, the computing device is preferably configured to calculate a data carrier-location-specific current waiting time for at least one data carrier based on its distance from the exit and the current rate of people leaving the exit per unit of time, and to provide it under its identifier for output to a smart device via a wireless network.

[0016] The invention thus enables a person waiting in line to dynamically display their current waiting time on their own smart device, e.g., smartphone, by scanning a nearby data storage device with the smart device. A complex stationary infrastructure in the form of distributed screens, their cabling, and secure installation are not required. The waiting person's smart device can display their exact waiting time at their respective location in the queue, where the scanned data storage device is located.

[0017] In this embodiment, the computing device can not only provide the current waiting times for output via the radio network, but preferably also receive the machine-read identifier from a smart device via the radio network and send the current waiting time provided under this identifier via the radio network to this smart device for output thereon.

[0018] In a second aspect, the invention provides a method for measuring the length of a queue of people having an entrance and an exit, comprising the steps of: a) arranging at least two data carriers in the queue at different distances from the exit, each data carrier having a unique identifier machine-readable by a smart device of a waiting person, which identifier encodes the distance of that data carrier from the exit; b) in a computing device: receiving identifiers machine-readable by smart devices and transmitted via a radio network over a predetermined time window, selecting the greatest distance from all distances encoded by the identifiers received in the time window, and outputting the selected distance as the length of the queue.

[0019] Preferably, the data carriers are arranged at approximately equal intervals along the queue.

[0020] It is particularly advantageous if the given time window is one tenth to ten times, preferably half to double, particularly preferably one time, the value ΔT opt = ΔL ⋅ D / SR + FR is.

[0021] With regard to further preferred features and advantages of the method according to the invention, reference is made to the above statements regarding the device according to the invention.

[0022] The invention is explained in more detail below with reference to exemplary embodiments illustrated in the accompanying drawings. In the drawings: Fig. 1 the use of the device and method of the invention in a queue of people in a schematic perspective view; Fig. 2 the device of the invention in a schematic plan view; Fig. 3 a method for displaying waiting times for waiting persons, which is optionally used within the scope of the device and method of the invention, in a flowchart; Fig. 4 the arrival of data carrier identifications machine-read by waiting persons in the device of Fig. 2 in a time diagram; Fig. 5 based on the received identifiers from Fig. 4 queue length measurements taken in a time diagram; and Fig. 6 the method of the invention in a flow chart.

[0023] In the Fig. 1 and 2A queue 1 of waiting people 2 is shown. Queue 1 has an exit 4 and a distant end E, i.e., people 2 are waiting in it from end E to beginning 4 to be allowed to leave exit 4 ("first in - first out", FIFO principle). For example, queue 1 is located in front of one or more entrances to an event hall, in front of one or more counters at a government agency or customer service office, in an airport departure hall, e.g., in front of an airport gate, in front of cash registers in a supermarket, at a stop for public transport such as taxis, buses, trams, trains, etc.

[0024] It is understood that several people 2 could stand next to each other in queue 1, and that several people 2 could also leave exit 4 simultaneously, in parallel, or in groups; all of this is encompassed by the terms "queue" and "FIFO principle" here.

[0025] Queue 1 can be linear as in Fig. 1 or curved or meandering as in Fig. 2 from end E to exit 4. Queue 1 can form "freely", ie people 2 wait in a disciplined manner without any lateral restrictions, or it can be separated by walls, railings, parapets, ropes or, as in the example of Fig. 1 and 2 by belt straps 5 that are stretched between stationary or portable belt stands 6. The belt straps 5 can be mounted in sections on the belt stands 6 so that they can be rolled up and each can be releasably anchored to an adjacent belt stand 6, as described, for example, in EP 2 937 463 B1, the disclosure of which is incorporated herein by reference. The lateral boundaries, e.g., the belt stands 5, can extend very far beyond the current end E of the queue 1, particularly in the case of short or half-empty queues 1, as, for example, in Fig. 2 shown. Where the boundaries end, an entrance 3 for queue 1 is created, through which the people 2 flowing into queue 1 pass until they reach the end E of the queue and begin to wait there.

[0026] In queue 1 there are N people 2 over a length L between exit 4 and end E. The person density, i.e. the number of people 2 in queue 1 per unit of distance (e.g. meter), is therefore N / L. Empirical values ​​for the person density D in usual queues in front of airport gates, for example, are 0.5 - 10 people / m, in particular 1 - 2 people / m, e.g. 1.4 people / m.

[0027] The current rate SR of people 2 leaving exit 4 of queue 1 per unit of time (e.g. second, minute or hour), also called the exit rate or "service rate" of queue 1, generally depends on the service, processing or passage speed of those facilities in front of which queue 1 is formed, e.g. the throughput rate of people at the entrances of an event hall, the service rate of customers at counters or cash registers, the control rate of people at a gate, and in particular also on the number of parallel such facilities after queue 1, e.g. the number of open counters, entrances, etc.

[0028] The waiting time WT i of a particular person 2 at a location P i (i = 1, 2, ...) of the queue 1, which is located at a distance L i from the exit 4, is WT i = N i / SR with N i ... Number of people 2 who are in queue 1 over the distance L i, where N i = L i ∗ D i is, with D i ... average person density over the distance L i (example: 1.4 persons / m).

[0029] For example, if location P i is 10 m away from exit 4, there are 14 = 10 m * 1.4 / m people 2 in queue 1 between location P i and exit 4; and the current service rate SR is 1 person / min, then the current waiting time WT i of a person 2 at location P i is 14 : (1 / min) = 14 min.

[0030] In order to give the persons 2 in the queue 1 the opportunity to know their current waiting time WT i at a specific location P i in the queue 1, either to calm their impatience or so that they can prepare to leave the queue 1, the device 7 described below and the subsequently based on Fig. 3 described procedures.

[0031] The device 7 cooperates with smart devices 8 carried by the persons 2, via a radio network 9 of the short-range, cellular, or long-range type, e.g., a WLAN, Bluetooth, NFC, or RFID network, or in particular a cellular data network according to one of the mobile communications standards 3G, 4G, 5G, 6G, or the like. The smart devices 8 are accordingly corresponding terminal devices that can communicate with such radio networks 9, e.g., corresponding mobile phones, smartphones, smartwatches, smartglasses, e.g., also for augmented reality (AR), but also any other type of "wearables" such as digital fitness bracelets, digital jewelry, smart implants, etc.

[0032] The smart devices 8 are each equipped with a reader 10 for machine-readable data carriers Q i , more precisely for reading an identifier id i stored on such a data carrier Q i . Each data carrier Q i has its own identifier id i , which is unique within the device 7.

[0033] The data carriers Q i can be any type of machine-readable data carrier known in the art that can be machine-readable by contact or, preferably, contactless, by the reader 10 of a smart device 8. Examples of data carriers Q i are plates, labels, inscriptions, engravings, adhesive labels, etc. with optically readable identifiers id i . The corresponding readers 10 of the smart devices 8 are optical cameras, such as the nowadays ubiquitous front cameras of smartphones that are used as smart devices 8. Or the data carriers Q i can be read wirelessly, e.g., RFID or NFC tags or labels, which can be read by matching RFID or NFC readers 10 built into the smart devices 8 with regard to their respective identifier id i stored therein. Any other form of machine reading of an identifier id i stored on a data carrier Q i is also conceivable, e.g.,acoustically, if the data carrier Q i is an acoustic beacon and the reading device 10 is a microphone, or the like.

[0034] The device 7 comprises at least two data carriers Q i arranged at different positions P i , ie at different distances L i from the exit 4, on the queue 1. In the Fig. 1 and 2 In the example shown, the data carriers Q i are mounted at the upper end of the belt stands 6. If, in a meandering course of the queue 1 - as in Fig. 2 shown - a belt stand 6 separates two adjacent, opposing sections 11, 12 of the queue 1, (at least) two data carriers Q i pointing in different directions R 1 , R 2 can also be attached to a belt stand 6, one of which points to the section 11 and the other to the section 12 and thus to different positions P i in the queue 1.

[0035] It is understood that the data carriers Q i can also be mounted in other forms along the queue 1, e.g. on boundary posts, railings, parapets, furniture, walls, on the floor, on the ceiling or on overhead support structures.

[0036] The identifier id i stored on the respective data carrier Q i and presented by the latter for machine reading encodes at least the distance L i of this data carrier Q i from exit 4. In the simplest case, the identifier id i directly indicates the distance L i of the data carrier Q i, e.g., id 4 = "4 m". However, the identifier id i can also indicate the distance L i indirectly, e.g., in the form "third belt stand in front of the exit", if the locations or distances L i of the individual data carriers Q i are predetermined or previously known and stored in a memory of the device 7.

[0037] Optionally, the identifier id i can additionally encode a web address of the computing unit 14 on the Internet, under which the waiting time WT 2 at the location P 2 of the respective data carrier Q i can be queried via the radio network 9.

[0038] In the Fig. 1 The example shown is the identifier id 2 of the data carrier Q 2 attached to the second belt stand 6 in front of the exit 4, which is implemented as a QR code: id 2 = https : / / qmetrix . com ∖ wt ? loc = VIE & qu = 7 & st = 2 and thus identifies the second belt stand (stanchion = 2) in the seventh queue (queue = 7) at the installation location "Vienna International Airport" (loc = VIE) as well as the web address "qmetrix.com" of the computing device 14.

[0039] The identifier id i of the data carrier Q i attached to the third belt stand 6 in front of the exit 4 is: id i = https : / / qmetrix . com ∖ wt ? loc = VIE & qu = 7 & st = 3 and thus identifies belt rack No. 3 at location VIE in queue No. 7.

[0040] In addition to the data carriers Q i , the device 7 comprises a detection device 13 for detecting the current output rate SR of the queue 1.

[0041] The detection device 13 can, for example, simply detect the number of available counters, passages or means of transport, etc. after the exit 4. The detection device 13 can also be electronically connected to such counter, passage or transport systems or even be part of them, e.g. be part of an electronic calling system with which counter staff call those waiting to leave queue 1 and which therefore itself detects the exit rate SR, or be part of an electronic traffic control system which controls or detects the available means of transport and thus detects the exit rate SR.

[0042] However, the detection device 13 can also be arranged at the exit 4 of the queue 1 and directly measure the current exit rate SR of the queue 1. For this purpose, the detection device 13 can be, for example, a light barrier, a turnstile, a proximity sensor, a camera, a foot switch mat, or any other type of device that can measure the number of persons 2 leaving the exit 4 per unit of time.

[0043] A computing device 14 is connected to the detection device 13. The computing device 14 is connected to the radio network 9 via an interface 15 and can communicate with the smart devices 8 via the radio network 9. A smart device 8 can thus receive ("push") or request ("pull") data from the computing device 14 via the radio network 9 and the interface 15. The interface 15 can be any data connection between the computing unit 14 and the radio network 9, e.g., a data connection via the Internet.

[0044] The computing device 14 calculates for each data carrier Q i , more precisely for its (approximate) location P i in the queue 1 or its (approximate) distance L i from the exit 4 of the queue 1, the respective (approximate) current data carrier location-specific waiting time WT i , i.e. depending on the output rate SR currently detected (at least approximately) by the detection device 13 according to the above equations (1) and (2) to WT i = (L i * D i ) / SR.

[0045] The person density D i used between the respective data carrier Q i and the output 4 can be an empirical or estimated value and can be predetermined, such as 1 - 10 people / m , e.g. 1.4 people / m , etc. Optionally, the person density D i can be measured in real time using a counting device 16 connected to the computing device 14.

[0046] The counting device 16 may be of any type known in the art, for example a series of step mats at the bottom of the queue 1, a series of proximity sensors or light barriers or - as shown - a camera with image processing means 17 for counting people in the camera image when the camera is directed towards the queue 1.

[0047] The counting device 16 can optionally measure for each data carrier Q i , ie for each distance L i , an individual person density D i or individual number of persons 2 that are located over the distance L i of the queue 1 between the respective data carrier Q i and the exit 4. This also allows congestion in the queue 1, which leads to local expansions and compressions in the queue 1, to be taken into account.

[0048] The current waiting times WT i calculated and provided by the device 7 can now be queried by the persons 2 using their smart device 8 and output thereon. To do this, a person 2 reads the identifier id i of the data carrier Q i closest to them using the reader 10 of their smart device 8, and this sends the read identifier id i via the radio network 9 to the computing device 14. The computing device 14 then returns the current waiting time WT i held under the identifier id i, i.e. calculated for the data carrier Q i, to the querying smart device 8 via the radio network 9. The person 2 waiting at a certain position P i in the queue 1 therefore only needs to scan the next best data carrier Q i with their smart device 8 and immediately receives their current, service rate-dependent waiting time WT i at location P i from the computing device 14.

[0049] The computing device 14 can calculate the data carrier location-specific waiting times WT i "in advance" and make them available for querying smart devices 8, also periodically updating them with the corresponding current recordings from the recording device 13 and optionally the counting device 14. Having currently precalculated waiting times WT i available—within the time granularity of the recording periodicity of the recording device 13 or counting device 14—saves computing resources in the computing device 14 if a large number of querying smart devices 8 are to be expected. Alternatively, the computing device 14 could also calculate the respective waiting times WT i only upon query by a smart device 8; optionally, the corresponding recordings from the recording device 13 and / or counting device 14 can also be initiated first to improve the timeliness of the waiting time calculation.

[0050] Fig. 3 shows various embodiments of the method executed by the device 7—in interaction with an exemplary smart device 8 and the radio network 9. In a first step 18, the data carriers Q i are arranged at different distances L i from the exit 4, e.g., distributed along the queue 1 on barrier railings, posts, belt racks 6, walls, floors, ceilings, etc. In the example shown, each data carrier Q i bears its identifier id i in the form of a camera-readable QR code or barcode.

[0051] In step 19, the output rate SR of queue 1 is detected by the detection device 13. In an optional step 20, the person density D or the person density D i occurring between data carriers Q i and output 4 can also be measured by means of the counting device 16.

[0052] Based on the recorded rate SR and the optionally measured population density D or D i , in step 21 the computing device 14 can now calculate the respective data carrier location-specific current waiting time WT i for (at least) a specific data carrier Q i or for each data carrier Q i of the set of all data carriers {Q i}, as explained above. The calculated waiting time(s) WT i are now available in the device 7, e.g., in a memory of the computing device 14, for output via the radio network 9 to a smart device 8, either for query ("pull") by the smart device 8 or for immediate transmission to it ("push").

[0053] In the "pull" case, the computing device 14 receives the identifier id i of a data carrier Q i machine-read by a smart device 8 in a step 22, searches the waiting time WT i calculated for this identifier id i from its memory in a step 23 and sends it to the querying smart device 8 via the radio network 9 in a step 24. In the "push" case, steps 22 and 23 could be omitted and the calculated waiting time(s) WT i could be sent directly to smart devices 8 connected ("logged in") to the device 7 via the radio network 9 (step 24).

[0054] The order of steps 19-24 can be changed for other embodiments, and individual steps can also be omitted. For example, if the waiting times WT i are not precalculated but only calculated upon query by a smart device 8, then step 21 could take place after step 22, and optionally step 23 could be omitted. In another embodiment, the detection step 19 and the optional counting step 20 could also take place after the query step 22, followed by the calculation step 21, and then step 23 could again optionally be omitted.

[0055] Furthermore, it is understood that the detection and counting steps 19, 20 can be repeated continuously or periodically, in particular if the waiting times WT i are precalculated in step 21 and kept ready for steps 22-24 in the device 7. For example, steps 19-21 could then be repeated periodically in a loop, while the query and transmission steps 22-24 are executed as a parallel process, each accessing the current state of the loop 19-21.

[0056] The computing device 14 can be connected to the registration device 13 and the optional counting device 16 on-site, for example, directly integrated into the registration device 14 at the exit 4 of the queue 1. Alternatively, the computing device 14 is physically separated from the registration and / or counting devices 13, 16 and connected to them via a data connection, e.g., the Internet. For example, the computing device 14 is a web server that can connect to the registration device 13 (and optionally to the counting device 16) via an Internet connection and to the smart devices 8 via another Internet connection as an interface 15 and the mobile network 9.

[0057] The arrival of the machine-read identifiers id i from the smart devices 8 in the computing device 14 can subsequently be used to obtain information about the status of the queue 1, such as the distribution of the persons 2 therein and, in particular, the length LQ of the queue 1. This information can be used by the operator of the queue 1 or the facilities located after the exit 4, e.g., customer, authority or check-in counters, entrances or passageways, cash registers, means of transport, etc., to open or close counters, cash registers, passageways, etc., as required, or to provide, time or plan means of transport. Fig. 1 , 2 and 4 bis 6 describe the device 7 extended by this functionality and a method for measuring the length LQ of the queue 1.

[0058] For the device 7 with queue length measuring function and the Fig. 4 bis 6 In the method described, it is not absolutely necessary for the persons 2 to receive their personal current waiting time WT i as a response from the computing device 14 when scanning a data carrier Q i. Rather, by machine reading the identifier id i of a data carrier Q i, any information or any content can be received from the computing device 14 via the radio network 9 and displayed on the smart device 8, for example messages, audio and / or video snippets for entertainment, advertising, financial information such as account balances, discount stamps or information about discount campaigns, frequent flyer mile credits, timetable information, e.g. about the expected arrival of the next means of transport at a stop, etc.The content available to a data carrier Q i is announced, for example, by an information board placed near queue 1 or data carrier Q i, in the manner of: "Scan here to find out your personal waiting time at this point", "Scan here to be informed about timetable delays", "Scan here to find out the expected arrival time of the next bus", "Scan here to receive 5 bonus miles", "Scan here to receive 5% off your purchase at this checkout", "Scan here to see pre-releases of the latest music videos by Adele and Ed Sheeran", or similar.

[0059] The measurement of the length LQ of queue 1 is based on the statistically valid assumption that persons 2 who flow towards queue 1 and reach the end E of queue 1, where they now have the time and leisure for the first time, machine-read the nearest data carrier Q i with their smart device 8 and thereby simultaneously communicate the identifier id i of this data carrier Q i to the computing device; just like many other persons 2 in queue 1 who at random times scan any of the data carriers Q i between the end E and the exit 4 of queue 1.

[0060] Fig. 4 shows the identifiers id i received in this way in the computing device 14 over time t, i.e. machine-read by smart devices 8 and transmitted via the radio network 9, or more precisely the initial distance L i encoded by these. As can be seen, the identifiers id i or distances L i are received at random times with irregular temporal distribution.

[0061] For a measurement of the current length LQ of the queue 1 at a selected time tn , hereinafter referred to as length measurement LQ n , the computing device 14 applies a time window ΔT n of length ΔT to the received signal from Fig. 4 The time window ΔT n for the length measurement LQ n extends back from time tn (or shortly before) and over the identifiers id i received in this time window ΔT n or the distances L i encoded by them.

[0062] Each time window ΔT n can have the same length ΔT or an individual length if successive length measurements LQ n are to be adapted to different measurement requirements, e.g. high spatial resolution or high temporal resolution, as explained at the beginning and in more detail later.

[0063] From the identifiers id i received in the time window ΔT n or the distances L i lying therein, the computing device 14 now selects the greatest distance LQ n = max(L i} ΔTn. The time window ΔT n can thus also be regarded as a "gliding maximum window". The computing device 14 can output the measured lengths LQ n of the queue 1 at an output 25, for example for display on a screen 26.

[0064] Fig. 5 shows a sequence of lengths LQ n of queue 1, measured at a measurement time tn over a past time window ΔT n, plotted against time t. As can be seen, the length LQ of queue 1 can increase or decrease over time. The time intervals ΔR between successive measurements LQ n and LQ n+1 can be chosen arbitrarily and independently of the time windows ΔT n, so that the time windows ΔT n can overlap or not.

[0065] The length of the time windows ΔT N is limited by the temporal resolution with which dynamic changes in the queue length LQ - growth and shrinkage - can be recorded. The shorter the time windows ΔT n , the faster the length measurement can follow dynamic length changes in queue 1. On the other hand, the brevity of the time windows ΔT n is limited by the desired spatial resolution of the length measurements LQ n . The longer the time windows ΔT n are, the greater the statistical probability that the data carrier Q i closest to the end E of queue 1 will be scanned at least once by a person 2 waiting there.

[0066] An optimal compromise between time resolution or dynamic responsiveness of the length measurement on the one hand and spatial resolution or length measurement accuracy on the other hand is achieved if each time window ΔT n is approximately equal to the value ΔT opt = ΔL ⋅ D / SR + FR is chosen, with ΔL is the average distance between two adjacent data carriers Q i , D is the average number of people 2 per unit length in queue 1, FRRate of people 2 entering the end 3 of queue 1 per unit time, and SRRate of people 2 leaving the exit 4 of queue 1 per unit time.

[0067] The inflow rate FR, also called "arrival rate" or "access rate" of queue 1, can be determined in the same way as previously described for the exit rate SR, for example by empirical value, estimation or a separate detection device 13' at the input 3 similar to the detection device 13 at the output 4.

[0068] If one of the two opposing measurement objectives - spatial resolution and temporal resolution - is to be favored, the time windows ΔT n above the value ΔT opt can be selected for increased spatial resolution and below the value ΔT opt for increased temporal resolution, for example in the range from 0.1 ΔT opt to 10 ΔT opt and in particular in the range from 0.5 ΔT opt to 2 ΔT opt .

[0069] Since the value ΔT opt depends on the population density D, the inflow rate FR, and the outflow rate SR, the time windows ΔT n , if selected according to the value ΔT opt , follow all changes in D, FR, and SR. Thus, if current estimated or measured values ​​of D, FR, and / or SR are used for one or more length measurements LQ n , their time windows ΔT n are self-calibrating or adaptive.

[0070] Fig. 6 shows the method carried out by means of the device 7 for measuring the length LQ of the queue 1 or a sequence {LQ n} of length measurements LQ n successive at time intervals ΔR in the form of a flow chart.

[0071] The first phase a) of the method comprises step 18 of arranging the data carriers Q i as for the method of Fig. 3 described.

[0072] In the second phase b) of the method, in a first step 27 in the computing device 14, the identifiers id i arriving in a time window ΔT n, ie received via the radio network 9 and the interface 15, or the distances L i coded by them are received and collected. The step 27 thus comprises a plurality of the receiving steps 22 of the method of Fig. 3 , so that reference is also made to their description.

[0073] In a subsequent step 28, the computing device 14 selects the largest distance among all distances (L i ) ΔTn collected in the time window ΔT n as the length measurement LQ n, ie LQ n = max L i ΔT n

[0074] In the following step 29, the length LQ n thus measured is output on the interface 25 of the computing device 14, e.g. for display on the screen 26.

[0075] Phase b) of the method can be repeated one or more times in a loop 30 at regular or irregular time intervals ΔR in order to Fig. 5 to generate the sequence {LQ n} of length measurements LQ n of queue 1.

[0076] The invention is not limited to the embodiments shown, but includes all variants, modifications and combinations of embodiments that fall within the scope of the appended claims.

Claims

1. A device for measuring the length of a queue of persons which has an exit and an end distanced therefrom, characterized by: at least two data carriers (Qi) arranged at the queue (1) at different distances (Li) from the exit (4), each having a unique identifier (idi) which is machine-readable by a smart device (8) of a waiting person (2) and which codifies the distance (Li) of this data carrier (Qi) from the exit (4); a computing equipment (14) having an interface (15) via which it can receive identifiers (idi) machine-read and sent via a radio network (9) by smart devices (8); wherein the computing equipment (14) is configured to select, from all the distances (Li) which are codified by the identifiers (idi) received in a predetermined time window (ΔTn), the greatest distance and to output it as the length (LQn) of the queue (1).

2. The device according to claim 1, characterised in that the data carriers (Qi) are arranged along the queue (1) distributed at approximately equal intervals (ΔL).

3. The device according to claim 1 or 2, characterised in that the predetermined time window (ΔTn) is a tenth to ten times, preferably half to twice, particularly preferably one time, the value ΔT opt = ΔL ⋅ D / SR + FR with ΔL average distance between two adjacent data carriers (Qi), D average number of persons (2) per unit of length in the queue (1), FR rate of persons (2) arriving at the end (3') of the queue (1) per unit of time, SR rate of persons (2) leaving the exit (4) of the queue (1) per unit of time.

4. The device according to any one of claims 1 to 3, characterised in that each data carrier (Qi) carries its identifier (idi) in the form of a camera-readable QR code or barcode.

5. The device according to any one of claims 1 to 4, characterised in that each identifier (idi) contains a web address of the computing equipment (14).

6. The device according to any one of claims 1 to 5, characterised in that at least one data carrier (Qi) is attached to a belt stand (6) or boundary post for the queue (1).

7. The device according to claim 6, characterised in that at least one belt stand (6) or boundary post, respectively, is provided with at least two data carriers (Qi) pointing in different directions (R1, R2).

8. The device according to any one of claims 1 to 7, characterised in that the computing equipment (14) is further configured to calculate, for at least one data carrier (Qi), from its distance (Li) from the exit (4) and the current rate (SR) of persons (2) leaving the exit (4) per unit of time, a data-carrier-location-specific current waiting time (WTi) and to provide it under its identifier (idi) for output via a radio network (9) to a smart device (8).

9. The device according to claim 8, characterised in that the computing equipment (14) is configured to receive the identifier (idi) machine-read by a smart device (8) via the radio network (9) and to send the current waiting time (WTi) provided under this identifier via the radio network (9) to this smart device (8) for output thereon.

10. A method for measuring the length of a queue of persons which has an exit and an end distanced therefrom, comprising the steps: a) arranging at least two data carriers (Qi) at the queue (1) at different distances (Li) from the exit (4), wherein each data carrier (Qi) has a unique identifier (idi) which is machine-readable by a smart device (8) of a waiting person (2) and which codifies the distance (Li) of this data carrier (Qi) from the exit (4); b) in a computing equipment (14): receiving identifiers (idi) machine-read and sent via a radio network (9) by smart devices (8) over a predetermined time window (ΔTn), selecting the greatest distance from all the distances (Li) which are codified by the identifiers (idi) received in the time window (ΔTn), and outputting the selected distance as the length (LQn) of the queue (1).

11. The method according to claim 10, characterised in that the data carriers (Qi) are arranged along the queue (1) distributed at approximately equal intervals (ΔL).

12. The method according to claim 10 or 11, characterised in that the predetermined time window (ΔTn) is a tenth to ten times, preferably half to twice, particularly preferably one time, the value ΔT opt = ΔL ⋅ D / SR + FR with ΔL average distance between two adjacent data carriers (Qi), D average number of persons (2) per unit of length in the queue (1), FR rate of persons (2) arriving at the end (3') of the queue (1) per unit of time, SR rate of persons (2) leaving the exit (4) of the queue (1) per unit of time.

13. The method according to any one of claims 10 to 12, characterised in that each data carrier (Qi) carries its identifier (idi) in the form of a camera-readable QR code or barcode.

14. The method according to any one of claims 10 to 13, characterised in that each identifier (idi) contains a web address of the computing equipment (14).

15. The method according to any one of claims 10 to 14, characterised in that step b) is repeated at least once in time intervals.