EP1045358A2 - System to transmit travel times for vehicles - Google Patents

Abstract

The system determines the travelling time of vehicles on the defined stretch of the road by subtracting the joining time from the leaving time for the particular stretch of the road using the roadside receivers. The time is averaged using several measurements for different vehicles. Each vehicle (1) carries a transponder card (2). Opposite the control points (K(n-1); K(n)) on the side of the road there a provided devices (3), e.g. induction loops, for activating the transponders in the passing vehicles and further devices (4) for receiving and evaluating the data received from the cards, e.g. TAG-ID signals.

Description

The invention relates to a system for determining travel times of motor vehicles according to the preamble of the claim 1. Determining the presence of motor vehicles at certain points of a traffic route or also theirs Movement over these points plays a role in road traffic technology in a variety of different use cases a crucial role. The used Methods are adapted to the respective application.

Are known, e.g. B. from EP-B-0 408 699, methods or systems, which only determined the current traffic situation on Places, e.g. B. at key points of a traffic route or of a traffic network. Thereby are stationary or mobile detectors, such as induction loops, Radar or infrared detectors the number, also measured the speeds of the motor vehicles, that pass the measuring point. If necessary a distinction was also made between motor vehicle types. The one with these Information obtained from measurements gives conclusions the traffic density at the respective key points to and can serve, for example, to avoid a traffic jam to recognize and the road users in time to warn.

Such measurements are a special case of this area of application with light signal systems controlled as required, under Under certain circumstances, such traffic light systems, their signal program depending on the traffic density on the confluence Traffic routes is controlled. Another special case are measurements of traffic load, which may also be only be carried out temporarily in order to be generally reliable To get values about the traffic volume, e.g. B. be used as a basis for traffic planning.

Another application in monitoring the flowing Traffic is the speed measurement of individual motor vehicles for the detection of overspeeds. In this case, as every motorist is familiar with, the individual Identify the vehicle and also the driver. To the measuring device itself and the implementation of the Measurement places high demands. Details are notoriously known, so that this is not discussed.

Another use case concerns toll stations on chargeable Traffic routes. In contrast to the above If no attempt is made to identify the motor vehicles per se, rather, it is only necessary to ensure that for those who pass Vehicles also paid the corresponding fee becomes. In the case of high traffic, this leads to the conventionally usual Collection of the toll fee by significant people Traffic delays. There has been no shortage of attempts to remedy this deficiency.

From US-A-5 488 360 it is known, for example, to in a toll station entering motor vehicles bundled one to direct radiating radio antenna. Is an incoming vehicle equipped with a mobile device, so the im Radio wave received a response signal with a vehicle Identification code. This response signal is on the Toll station received, using a transceiver in a binary code converted and fed to a computer. The computer compares the received code with a valid table Identification codes and gives a positive comparison a command to a corresponding toll station facility from, the passage through the toll booth for the identified Release motor vehicle. An independent, in the present Context less interesting function of this known solution is an automatic fee entry or billing.

TAG" bezeichnet) einzusetzen. Die Transponderkarte wird an einer Meßstelle durch ein induktives Feld dazu angeregt, dieses Feld zu modulieren. Das modulierte Feld wird von einer Auswerteeinrichtung empfangen und ausgewertet.From US-A-5 808 550 it is also known to monitor the authorization to pass through a toll booth, instead of the effort for installing a mobile telephone system in a motor vehicle a passive transponder card carried on or in the motor vehicle (transponder cards are often used as

The transponder card is stimulated at one measuring point by an inductive field to modulate this field. The modulated field is received and evaluated by an evaluation device.

Such transponder cards have long been in different Form known for different applications. In simple Execution, as in the example cited, are given by transponder cards on inductive excitation no more than a predetermined response signal. This response signal can be completely uncoded and only activated in one receiver an acoustic warning signal or at best contains one Identification code. In the example cited this is only indicated that the response signal z. B. Identification enable a motor vehicle at a toll booth should.

From US-A-5 804 810 is an example of a much more complex one Known solution to objects to be monitored that are transported in vehicles, for example Attach and use transponder card. So that's it possible, the marked object by means of electronic Transmitting / receiving devices also in moving motor vehicles to pursue on its way. Have the transponder cards in this case a relatively complex electronic circuit with a transmitting and receiving part and a microprocessor consisting of a microcontroller and connected storage device. These transponder cards are able to perform more extensive functions when activated. In the example cited, the transponder cards equipped with a GPS module (GPS = Global Positioning System) his. This is the exact position of a transponder card document the assigned object. The microprocessor is equipped with a peripheral interface, which is also used for data entry to update the Memory content of the transponder card is provided. Consequently is a bidirectional communication of a querying unit with the individual transponder cards in particular Larger scope possible if the latter additionally transmit / receive devices for infrared connections over shorter Distances as well as for radio connections over larger distances have. The example shows that the possibilities modern circuit technology even complex structures Have transponder cards implemented. Inevitable but with increasing complexity it takes the transponder card integrated circuit also the weight and format of the Card too. This is mainly because of the corresponding to the circuit adaptable power supply.

Like the solution for a known from US-A-5 606 313 Shows transponder card as another example is trying this technical difficulty through a special efficient use of the available electrical Encounter energy. As sensible as this solution can be like, this approach may not be the underlying problem fix that compared to storing electrical energy to the electrical circuit technology still disproportionate more volume and weight.

In addition to the use cases described above, in which determining the presence of motor vehicles at certain Points of a traffic route plays a role another application in the present case is special Importance. This affects the travel time determination of motor vehicles on certain sections of a traffic route or a network of traffic routes. Knowing current Travel times become more important, the more traffic control or Enforce traffic control systems on the market Invention relates to this field of application and relates on a system for determining travel times from Motor vehicles.

Travel time is one of the fundamental parameters in traffic engineering, it is defined as the travel time between two locations on a route is a route-related Size. You can e.g. B as an input variable for traffic control procedures used or also used to get current out of it and the most accurate information possible about traffic flows to derive. With the importance of this size for traffic engineering it is natural that there are already a multitude of proposals became known the problem one on a current Traffic situation sufficiently precisely related travel time determination to solve.

So z. B. from DE-A-41 05 809 a system for a traffic flow analysis known by means of local data acquisition. Here a video camera is used as a detector to monitor traffic at a traffic junction. Their captured images are digitized and by a subordinate computer prepared. In this are standard patterns common vehicle types saved. With procedures of Pattern recognition becomes information from a sequence of video images won about how many vehicles are where, when have found what type, e.g. B. Bus, truck, car, two-wheeler they were and which direction they were taking. To because of that data obtained will perform traffic flow analyzes suggested the video camera in a mobile device too integrate. On the other hand, a stationary video camera is said to be then be preferred if by means of the thus obtained Traffic information Traffic control systems are to be controlled.

The solution cited above by way of example is not immediate geared towards individual, possibly also to determine only average travel times on a section of the route. In itself, it would be conceivable from the vehicle speeds on the travel times at the local measuring point the subsequent section of a traffic route or Close transport network. This derivative but was then based on a single value at a local Measuring point and would be too imprecise to even travel time forecast.

In contrast to this, the known methods, which are designed to determine actual travel times, are based on route-related data acquisition. There are two possible approaches. One of these approaches is as Floating car "method is known. Individual vehicles are used, which are individually equipped with special measuring and transmission devices. Depending on the equipment of the on-board system, the cruising speed or travel time on individual sections of the route are calculated in the motor vehicle. The results are transmitted to a central unit The traffic data received from the individual motor vehicles is aggregated there, and the higher the current number of these individually equipped vehicles on the route, the higher the quality of the travel times determined in this way.

A second group of known systems respectively By contrast, the procedure for determining travel times is based on a preferably fixed, local data acquisition, which, for. B. is executed via loop detectors. Using feature vectors an attempt is made to type the passing vehicles to describe and sufficiently significant data for to win a bunch of vehicles. This data is sent to the next measuring point downstream in the direction of traffic transfer. There is now an attempt to determine the arrival time of the Vehicle groups by correlating the transmitted with the local measured data.

With this group of solutions, there is an essential one Problem in that individual vehicles often with the feature vectors specified by the system are not precise enough are described. Furthermore, through individual driving behavior, e.g. B. by overtaking, entrances or exits, mixing in the vehicle stream. These are all the more serious the longer the basis of the measurements Route section is. The correlation methods to be used are therefore complex, computationally intensive and still guarantee not always flawless results.

The present invention is therefore based on the object a system for determining travel times of motor vehicles of the type mentioned to create that with as much as possible simple means reliable but still so significant Vehicle description provides that travel times are more individual Motor vehicles on a route section with a sufficient Number of measurements with reasonable effort and are still to be recorded safely.

This task is carried out in a system of the type mentioned at the beginning Art according to the invention in the characterizing part of the claim 1 described features solved.

Compared to many known solution attempts, which is a complex one Infrastructure need to get current travel times from The solution according to the invention has to measure motor vehicles impressive advantages. The technology of transponder cards, in connection with the facilities that activate and read them out, is available with a wide range. As the examples cited at the beginning demonstrate, the transponder card is also a means that, among other things, already has been proposed for use in the motor vehicle if the practical application only begins sporadically. The on the one hand, existing specialist knowledge enables inexpensive and in terms of their dimensions and energy consumption to produce optimized transponder cards, on the other hand vehicle owners are becoming more familiar with this medium. These are the prerequisites for readiness on the part the manufacturer of motor vehicles and above all the user, this medium is also available in sufficient numbers Use motor vehicle. That is one of the most important Preconditions for the market implementation of a system for Determination of travel times to fulfill, namely if possible have a sufficient number of motor vehicles at short notice To equip transponder cards. This is to ensure that in a statistical distribution that is sufficiently equipped at all times Vehicles actually participate in traffic. The one with it the sample width to be achieved is sufficiently representative, to ensure current travel times with sufficient security determine.

Further developments of the invention as defined in subclaims show, it is particularly advantageous that the system to determine travel times flexibly to a used one Type of transponder cards can be easily adapted. So can use the transponder cards as passive units and accordingly the devices for activating the transponder cards be designed as induction loops, the Only one individual transponder card when activated Enable identification. So this just sets Transponder cards in a very simple embodiment ahead, the inexpensive to manufacture and operate are particularly economical. Such transponder cards are already used as season tickets for users of Toll roads used and could be easily for the further purpose for determining travel times to use. In this application, however, lies a larger share of expenses in the evaluating facilities of the system.

According to another development of the invention Transponder cards designed as active units, the one rewritable storage device for temporary storage an identification code for at least the last one passed control point and a time information about the Show the time of passing this checkpoint.

Then the evaluation devices at the control points be designed in such a way that it is within reach Transponder cards for sending out in their storage device currently saved data and for temporary storage of your own identification code. Active Transponder cards of this type can be used, for example, for the commercial sector of road users of interest to meet its logistics needs for a fleet of To meet motor vehicles. In this case too the determination of the travel time the importance of an additional Function.

Figur 1 schematisch ein System zur Reisezeitermittlung von Kraftfahrzeugen, die zu diesem Zweck mit Transponderkarten ausgerüstet sind, die an ortsfesten Kontrollstellen abgefragt werden,

Figur 2 für das System zur Reisezeitermittlung nach Figur 1 in Verbindung mit dem Einsatz von passiven Transponderkarten ein Blockschaltbild für eine Kontrollstelle, in der die von den Transponderkarten abgerufenen Daten verarbeitet werden und

Figur 3 ein Blockschaltbild für eine weitere Ausführungsform einer Transponderkarte, die für eine bidirektionale Verbindung mit den abtragenden Kontrollstellen ausgerüstet ist.

Exemplary embodiments of the invention are explained in more detail below with reference to the drawing, in which:

1 schematically shows a system for determining the travel time of motor vehicles which are equipped for this purpose with transponder cards which are queried at fixed control points,

Figure 2 for the system for travel time determination according to Figure 1 in connection with the use of passive transponder cards, a block diagram for a control point in which the data retrieved from the transponder cards are processed and

Figure 3 is a block diagram for another embodiment of a transponder card, which is equipped for a bidirectional connection with the ablating control points.

In Figure 1 are schematic for one not shown in detail Traffic route two at a defined distance from each other, Control points successive in the direction of traffic K (n-1) and K (n) are shown. The inspection bodies are expediently set up at the entrances and exits of the trunk road, but can also in critical sections of the route also be provided in between. In the example of Figure 1 drives the same motor vehicle 1 in succession the control points located at a distance a from each other K (n -1) or K (n). As indicated schematically, the motor vehicle 1 is equipped with a transponder card 2. There is a plurality for the present purpose of embodiments of the transponder card 2 suitable. In the simplest case, it is a purely passive one Transponder card, which is only activated when activated Identification signal, d. H. emits a signal based on which the motor vehicle is also individually identifiable. How will still be shown, but it is also advantageous, more complex trained transponder cards 2 to use. This Free movement in the design of the transponder card 2 is a major advantage that it z. B. allowed transponder cards, carried in the vehicle for other reasons for the further purpose of determining the travel time to use.

In the embodiment shown in FIG. 1, it is assumed that that at the control points K (n - 1) or K (n) induction loops 3 are provided, for example in the Roadway of the traffic route are relocated to those in motor vehicles 1 carried transponder cards 2 when passing the to activate the respective control point. That from the transponder card 2 thereupon issued identification signal is in a the induction loop 3 spatially assigned evaluation device 4 received, evaluated, as below is explained in more detail and the result to a central Traffic control computer 5 transmitted.

FIG. 2 is a block diagram of an embodiment of the Evaluation device 4 shown, which is based on that in connection with it transponder cards 2 in their simplest Design are used. The only system-related Requirements for the properties of the transponder cards 2 in this case is your individual identification option when passing the checkpoints z. B. K (n) by the evaluation device 4. This means the evaluation device 4 receives this from an activated transponder card emitted identification signal and sets this in a converter 6 into a further processable identification code TAG ID around. The evaluation device 4 is equipped with a clock, e.g. B. equipped with a radio clock 7, so that the time of Receipt of the respective identification code TAG-ID is fixed and linked from the latter to the corresponding time a defined data record 8 is to be formed.

With this gained, however, each record is one Determining the travel time of the motor vehicle 1, although it is not yet possible. For travel time determination it is necessary to match each other, d. H. identified by the same identification code TAG-ID Records 8 of the different, preferably two each consecutive checkpoints in the direction of traffic, e.g. B. K (n - 1) and K (n) correlate and from the time information of the corresponding data records the individual Travel time of the associated motor vehicle 1 on the corresponding one To calculate route section.

This would be possible in the form that the evaluation devices 4 of the individual control bodies B. K (n) the individual data records transmitted to the central traffic control computer 5 and the evaluation is carried out there. In the embodiment of Figure 2 is instead a decentralized evaluation chosen. The evaluation device 4 is equipped with a remote data transmission unit 9 equipped by means of which the local prepared data records 8 sequentially as data stream 8 (n) the control point K (n) to the downstream in the traffic direction adjacent control point or its evaluation facility be transmitted. The same goes for the evaluation device 4 (n) via another remote data transmission unit 9 'a data stream 8 (n-1) with corresponding data records the neighboring upstream in the direction of traffic Transfer control point K (n - 1).

For the formation of the correlation of individual data records from the Data streams 8 (n-1) or 8 (n) is the evaluation device 4 (n) equipped with a processing unit 10. In figure 2 is shown schematically that the sequentially occurring Records of these two data streams are cached become. The identification codes TAG-ID of the stored Records of both data streams 8 (n - 1) and 8 (n) are checked for agreement. In the event of a match the travel time becomes the difference of the time information of the individual vehicle. The in the Processing unit 10 are determined travel times either as individual values of anonymous motor vehicles or from time to time as average travel times by the individual Evaluation devices 4 to the central traffic control computer 5 transferred.

In the embodiment shown in FIG complex transponder card 2 used. The structure the transponder card 2 in this embodiment is only reproduced schematically since it is assumed to be known can be. The transponder card 2 is with a microcontroller 21 equipped, for example, connected to it Units run over a bus system 22. Of the units connected to the microcontroller 21 are in Figure 3 only those units specified in the present Use case are of particular interest. To belongs next to a storage device, for example designed as a circulation memory 23 (FIFO = First-In-First-Out) is, a converter 24. The converter 24 runs over a Radio modem 25 with the correspondingly configured evaluation device 4 a control point now bidirectional.

In particular the radio modem 25, but also the microcontroller 21 itself and the units 23, 24 connected to it Considerable power consumption in the active operating state. In order to also take this into account in FIG. 3, in addition to a controlled power supply unit 26, an activation unit 27 and an activation sensor 28 are shown. With the units 26 to 28 the power consumption is achieved to optimize the transponder card 2. The microcontroller 21 and the units connected to it via the bus system 22 23 and 24 and the radio modem 25 are normally in reset an energy-saving idle state. Only when one equipped with the transponder card 2 motor vehicle 1 a control point and thus within the scope of the Evaluation device 4, possibly also one of one Induction loop 3 emitted induction field arrives, the activation unit 28 via the activation sensor 27 controlled and caused the electronic units to control the transponder card in the active operating state.

In the active operating state, the transponder card 2 is capable of Information about the radio modem 25 with the evaluation device 4 exchange. Above all, this affects information which are stored in the circulation memory 23. The saved there As schematically indicated, data records should have an identifier field NN and a date field Dat. In the identifier field NN an identifier is stored on the basis of which one checkpoint previously passed must be identified. In the associated Date field Dat is the point in time at which the corresponding control point has been passed. In the chosen one Embodiment is assumed that the circular memory 23rd comprises a plurality of such storage locations, so that this memory content shows a travel course over a plurality of Route sections can be reconstructed. For the real one Travel time determination on individual sections of the route is however, this is of secondary importance at best.

Depending on the expansion of the operating system for the microcontroller 21, it is now conceivable that the evaluation device is called up 4 via the radio modem 25 only the last one in the circulation memory stored data record or already by the microcontroller 21 the travel time for the last trip Route section is calculated and transmitted. Advantageous is there when the electronics of the transponder card 2 too includes a radio clock, not shown in Figure 3. Otherwise can also receive the time information from the evaluation device 4 can be delivered. Appropriately in the the evaluation device 4 transmits the identifier transferred to the last control point passed. In this Trap can the evaluation device 4 passing motor vehicles regardless of the direction of traffic. Finally, the evaluation device 4 gives its own identifier to the transponder card 2, which is then in the corresponding Storage space of the circulation memory 23 together with the current one Time information is saved. Once these operations are completed, the controlled power supply unit continues 26 the electronics of the transponder card 2 in the energy-saving Hibernation back.

The exemplary embodiments described above demonstrate that entirely different embodiments of transponder cards 2 can be used in a system designed according to the invention for determining travel times of motor vehicles. The more Intelligence "is placed in the transponder cards, the less effort is required with the fixed devices of the system. It is also understandable for the person skilled in the art that different types of transponder cards can also be used alongside one another in such a system for determining the travel times of motor vehicles. All that is required is that certain minimum conditions with regard to the system interface, that is to say for the defined communication of the local evaluation devices with the transponder cards, have been established and adhered to.

Claims (4)

System for determining travel times of motor vehicles on at least one section of a traffic route delimited by control points on both sides, with measuring devices for determining the times for access to and exits from the section for certain motor vehicles and with evaluation devices for determining individual travel times of the individual motor vehicles on the corresponding one Section of the route from the difference between departure times and arrival times of the individual motor vehicle or for determining a current average travel time averaged over a plurality of motor vehicles, characterized in that at least individual motor vehicles (1) each carry a transponder card (2) that at the control points ( K (n -1); K (n)) of the route section each have a device (for example 3) for activating the transponder card of the passing motor vehicle and also a device (4) for receiving and evaluating the thereupon data signals emitted by the transponder card (e.g. B. TAG-ID) is provided. System for determining travel times of motor vehicles according to claim 1, characterized in that the transponder cards (2) are designed as passive units and the devices for activating the transponder cards are designed as induction loops (3), the transponder cards in the activated state allowing their individual identification . System for determining travel times of motor vehicles according to claim 2, characterized in that the evaluation devices (4) are equipped with a clockwork (7) for each data signal (TAG-ID) received and processed by a transponder card (2) with time information about to couple the time of its receipt and furthermore a processing unit (10) for correlating the data records (8 (n-1) received at the entrance to the route section with the data records (8 (n)) received at the exit from the route section and for determining the travel time from the difference in the time information of two correlating data records. System for determining travel times of motor vehicles according to Claim 1, characterized in that the transponder cards (2) are designed as active units which have a rewritable storage device for temporarily storing an identification code for at least the last control point passed (e.g. K (n - 1 )) as well as a time information about the time of passing this checkpoint and the evaluation devices (4) at the checkpoints (e.g. K (n)) are designed such that they can reach transponder cards (2) within their range for sending out the in cause their storage device (23) currently stored data and to temporarily store their own identification code.

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