EP1768070B1 - Method and device for determining a point in time for automatically establishing a connection - Google Patents

Description

The invention relates to a method and a device for determining a point in time for the independent establishment of a connection from a vehicle-mounted, phase-operated on-board unit to a background system of a toll system and an on-board unit with such a device.

Tolling systems, in particular automatic tolling systems, are based on the fact that the distances traveled and toll road are recorded and the toll collection data determined with the registration are used. With the toll bill, finally, a fee is calculated, which is charged for driving on the toll roads in total. In automatic toll systems, the detection of the traveled routes is carried out in an automatic, that is in a self-contained manner, which generally depends on the toll system. Vehicles whose vans are tolled are equipped with an on-board unit for the purpose of automatic vehicle tracking, which records the routes traveled and transmits the collected data to a background system of the toll system. In the following, these on-board units are also referred to as "OBU", OBU stands for the term "On Board Unit". This term and thus also its abbreviation OBU is meanwhile a fixed technical term for a specialist for automatic toll systems.

Automatic toll systems thus consist of the above-mentioned OBUs and a background system which operates a data exchange with the OBUs. The data exchange takes place in a wireless manner. It has enforced a radio-based transmission because of its advantages over data-carrier-based or even wired transmission paths. One of the advantages of the radio-based Transmission paths is their spatial independence. However, disadvantages are also associated with the advantages, which are, for example, within the range of the radio signals. Therefore, a radio transmission path that is available in many countries of the world is used to transmit the data. This is the case, for example, in the case of a mobile radio network. In the meantime, a nearly nationwide mobile network has been set up in Europe according to the GSM standard (GSM = Global System for Mobile Communication) by various mobile network operators. By means of such a radio network, it is also possible far from the background system remote OBUs to transmit the collected data on the traveled routes to the background system.

The data transmission is not done constantly in a held while driving connection. On the contrary, it has proved advantageous to carry out the data transmission during a connection established from time to time. After successful data transfer, the connection is terminated. The timing and timing of the connection setup are basically variable.

A partial function of the OBUs is thus to establish the connection to the background system and to transmit the data at a predetermined time, for example once during a day. In order to avoid load peaks in the background system and also in the mobile radio system used to establish the connection, the OBUs are configured such that the times for establishing a connection are not the same for all OBUs, for example the connection establishment times are subject to statistical equal distribution. This is to ensure that the burdens of the background system and the mobile radio system are evenly distributed. However, it is not always possible to establish a connection at the predetermined time, either because no cellular connection is possible or because the OBU is out of service because the vehicle is also out of service. If the OBU can not establish a connection at the predetermined time, then The OBU establishes the connection when this is technically possible again, that is, when there is sufficient network coverage to establish a mobile connection or when the vehicle has been put back into service.

From the DE 101 04 499 A1 A toll collection system is known in which various criteria are defined for the transmission of data from an OBU to a background system via a GSM connection. OBU data is sent when a specified shipping limit is reached or when a parameterized period is exceeded. In addition, the same data is sent again if the OBU does not receive a receipt from the central office.

A method for reducing the load of a mobile network by an automatic toll collection system is in the DE 44 44 142 C1 described. In this case, only individual vehicles are optically detected to control non-or Falschzahlern at a control point, which must acknowledge their payment via the mobile network after the control point.

Some types of vehicles are subject to a time-limited driving ban in the context of traffic regulations. Such a driving ban exists, for example, in Germany for trucks of Güternah- and long-distance freight. It is valid in the period from Saturday evening 22.00 clock to Sunday evening 22.00 clock and on public holidays until 22.00 clock. That is, during this period, a large number of toll vehicles is out of service. As a result, their OBUs are also out of service and do not connect to the background system of the toll system. With the end of the ban on Sunday evening at 22.00 clock, a large number of vehicles and OBUs are put back into operation. Thus, the desired statistical equal distribution of the utilization of the background system as well as the statistical equal distribution of the utilization of the mobile network is no longer given. A peak load is therefore required for both systems.

Such a peak load can also be observed for individual days. In the morning, many vehicle drivers start their work and put vehicles and OBUs into operation. The same applies to the early afternoon, when many drivers have finished their lunch break and also put the vehicles back into operation. OBUs whose predetermined time for connection establishment lie in the time windows that are characterized by standstill, establish the connection to the background system after a resumption of operation. Thus, even on weekdays times with peak loads arise. This is disadvantageous because the background system and also the mobile radio system should be dimensioned so that these peak loads are processed without disturbances or delays. This leads to a high investment volume in the production of the background system and the mobile radio system.

There are various ways to scatter the times for establishing a connection. So z. B. the connection to a randomly selected time after commissioning of the on-board unit done. However, there is a problem. If one also allows time points relatively late in relation to the start of operation of the OBU, then the probability that many vehicles fall short of the travel time required for this is very great. In this case, no connection to the background system of the toll system is established for these vehicles. If, on the other hand, one only allows times for connection establishment relatively shortly after the start of operation of the OBU, the likelihood of establishing a connection with the background system is very high, but the background system and the communication network used for establishing the connection are still relatively heavily loaded during peak load periods.

It is therefore an object of the present invention to provide a method and apparatus for determining a time to independently establish a connection from the OBU to the background system of a toll collection system and a corresponding on-board unit, thus avoiding the peak loads of the toll system's background system.

This object is achieved by a method according to claim 1 and by a device according to claim 12 or by a vehicle on-board unit according to claim 13.

The inventive method is based on the features described below.

An onboard vehicle unit, hereafter referred to as OBU, must systematically establish at intervals from one another either regularly or irregularly a connection to the background system of the toll system. This should be done within predetermined time periods. According to the invention, a suitable time for independent Establishment of a connection determined by the on-board unit with the background system. This is done in such a way that the time of the connection setup during a current operating phase is determined as a function of a duration of a previous operating phase of the OBU. This advantageously statistically determines a value which, on the one hand, corresponds to a time at which the OBU is very likely still in operation and, on the other hand, is not too short after the startup time of the OBU. This reduces the likelihood that the next possible time of connection establishment coincides with other OBUs at the same time. This avoids peak loads on a background system of a toll collection system. Even if z. For example, if a variety of OBUs are put into operation on a Sunday evening at 10:00 pm or on the morning of a business day, then the previous operating hours of the OBUs are different. Thus, due to the dependency of the determination of the time of connection establishment for each OBU, a different time for establishing the connection with the background system of the toll system.

The OBU required for carrying out such a method comprises a device for determining a point in time for the independent establishment of a connection from a vehicle-mounted, phased-operated on-board unit to a background system of a toll system. Furthermore, an OBU embodied in this way comprises an operating time determination device which is designed, for example, as a timer or clock and is provided with an interface in order to detect the events of the switching on and off, and thus the operating time, of the on-board unit. Furthermore, an OBU configured in this way comprises a memory device for storing the values of the time duration of the operating phases of the on-board unit and a point-of-time calculation unit for calculating the time of the connection establishment as a function of a duration of a preceding operating phase of the on-board unit.

The dependent claims and the further description each contain particularly advantageous embodiments and developments of the invention.

As a rule, the operating times of the OBU coincide with the operating times or the operating phases of the respective vehicle. Thus, the operating phases of the OBU are usually coupled with switching on the ignition of the vehicle. Thus, turning on the ignition will cause the OBU to turn on and turning off the ignition will consequently stop the operation of the OBU. At least, however, the operating hours of the OBU should match the travel times of the vehicle, that is, when a vehicle is in motion, the OBU should be safely in operation.

A particularly advantageous embodiment provides for the determination of the time for autonomous construction of the connection to consider several previous operating phases. For this purpose, the OBU has a memory device for storing the values of the duration of several operating phases. "Multiple" means that not only the last operating phase is taken into account, but, for example, a number of n preceding operating phases are used to determine the time to establish a connection with the background system. Ideally, the storage device is designed so that the most recent value, i. H. the operating time of the last operating phase, the oldest value displaced from the memory device, so that always current values are stored in the memory device. This is particularly advantageous when the operating times of a vehicle change due to different uses of long operating times to short operating times.

A further advantageous embodiment of the invention provides to form a statistical value from the set of the determined and stored operating phases. As statistical values, the arithmetic mean, but also other values, such as the median of the set of all stored in the storage device operating periods, find useful use.

When determining a statistical value, in particular an average value, it is advantageous to exclude so-called "outliers" from a value set from the calculation of the statistical value. The invention provides for a predeterminable number of maximum and / or minimum values, i. minimum and maximum operating periods, to exclude from the calculation. For the determination of the average duration of the operating phases z. For example, the upper and lower extreme values can be described as outliers. In this case, the number of extreme values to be excluded from the calculation can either be predetermined in the OBU or predeterminable for all OBUs by a system administrator of the background system. As a result, the system administrator has an influence on the calculation of the mean values of the operating phases and thus also on the distribution of the times of the connections for the data transmission of the OBUs.

An advantageous embodiment of the invention provides to determine the exact time for independent establishment of the connection with the background system according to a statistical distribution, which depends on the duration of the previous operating phase, preferably of several previous operating phases. For this purpose, for example, a Gaussian normal distribution is preferred.

Particularly preferably, the time for autonomous establishment of the connection within a time window is within the current operating phase, which is determined as a function of the duration of the preceding operating phase (s) according to a predetermined or predeterminable rule.

Predeterminable rules for determining the time within such a time window as well as predeterminable rules can be provided for determining how such a time window is to be determined. To determine the time after In the manner just described, the above-mentioned point-in-time calculation unit must be constructed in such a way as to determine the time window on the basis of predetermined rules and to determine a time in the time window. The calculation rules are predeterminable by the system administrator of the background system and are used during an existing radio connection z. B. transferred to the OBU for the next contact. Alternatively, the calculation rules are fixed in the background system or in each device for determining the connection establishment time or the OBU. An example of the last variant is to place the time of the connection establishment with the background system in a window, which comprises the third quarter of the average operating time. It is likewise provided for the system administrator of the background system to make such fixed settings for all OBUs jointly or in each case for individual selected OBUs in order to give the system administrator an opportunity to influence the calculation of the connection time at least in a statistical manner.

Within this time window, the choice of the connection time can in principle be made according to any distribution. Preferably, however, it takes place after an equal distribution. Ie. Each time calculation unit for the respective OBU determines the time of connection establishment within this time window according to a random principle on which a statistical equal distribution is based. Nevertheless, a reduction in the peak loads for the background system can still be achieved via the set of all OBUs, even if a large number of OBUs have similar start times and operating times.

In a further advantageous embodiment of the invention, the time of the connection establishment in dependence on a current time of day and / or a current calendar day and / or a current position and / or route is determined. Thus, the relative time window of the statistical value or the arithmetic mean of the time duration becomes the operating phases and / or the number of maximum and minimum values of the duration of the operating phases for certain days of the week. This is given an advantageous consideration of the different behavior of the driver on different days of the week. For example, on Sundays and public holidays there are completely different working hours and working rhythms compared to weekdays. A typical example of this is the start of the journey one hour before a weekend driving ban. An OBU with an average operating time of 4 hours will most likely not connect to the background system during the one-hour drive because the calculation basis is 4 hours of operation. On the other hand, if the calculation bases are adapted to the days of the week, places and times of day, an OBU based on this information will establish the connection to the background system within the expected operating hour before the weekend driving ban.

In the method according to the invention, further specifications of the background system are preferably taken into account, such. For example, specify that the OBU should contact the background system only once within a specific time period (for example, once every 24 hours). In order to fulfill these requirements, the calculation rules may be temporarily modified if necessary for a concrete determination of a connection establishment.

The connection between the OEU and the background system can, in principle, take place via any radio interface. However, if this - as described above - a mobile network used, a greater location independence is comparable given small transmission power of the OBUs, as this is possible with other radio links.

In the foregoing, the method and apparatus for determining a time for self-establishment of connection are described. It is therefore advantageous to incorporate this device directly into a vehicle on-board unit for a toll system, i. H. into an OBU, to integrate. An on-board unit equipped in this manner advantageously comprises a toll collection device, a transmission device for transmitting collected toll data to the background system, and a receiving device for receiving control data from the background system. Alternatively, the inventive device for determining a connection establishment time but also as a separate unit, for. B. be designed for connection to a conventional OBU or to retrofit.

FIG 1

eine schematische Darstellung eines Fahrzeugs und eines automatischen Mautsystems,

FIG 2

eine schematische Darstellung einer Bordeinheit (OBU),

FIG 3

eine grafische Darstellung der Verteilung von Fahrbeginn-Ereignissen über einen Tagesverlauf von 24 Stunden,

FIG 4

eine grafische Darstellung über die statistische Verteilung der durchschnittlichen Fahrdauern der Fahrzeuge,

FIG 5

eine grafische Darstellung der Verteilung der Verbindungsaufbau-Ereignisse über einen Tagesverlauf von 24 Stunden,

FIG 6

ein Ablaufdiagramm zur Bestimmung des Zeitpunktes des Kommunikationsaufbaus mit dem Hintergrundsystem,

FIG 7

ein Berechungsbeispiel für ein Fahrzeug mit kurzen Fahrzeiten,

FIG 8

ein Berechnungsbeispiel für ein Fahrzeug mit langen Fahrzeiten,

FIG 9

eine grafische Darstellung zu den Berechnungsbeispielen der Figuren 8 und 9.

The invention will be explained in more detail below with reference to the accompanying figures with reference to embodiments. Show it:

FIG. 1

a schematic representation of a vehicle and an automatic toll system,

FIG. 2

a schematic representation of an on-board unit (OBU),

FIG. 3

a graphical representation of the distribution of start-of-drive events over a 24-hour day

FIG. 4

a graphic representation of the statistical distribution of average vehicle lives,

FIG. 5

a graphic representation of the distribution of the connection establishment events over a daily course of 24 hours,

FIG. 6

a flow chart for determining the time of communication with the background system,

FIG. 7

a calculation example for a vehicle with short travel times,

FIG. 8

a calculation example for a vehicle with long travel times,

FIG. 9

a graphic representation of the calculation examples of the FIGS. 8 and 9 ,

FIG. 1 shows a schematic representation of a vehicle 1 with an on-board unit or OBU 2, which is arranged in the vehicle. The OBU 2 is electrically connected to a power supply network 3 of the vehicle and obtains the necessary for the operation of the OBU electrical energy from this power grid 3. By means of an electromechanical switching element 4, for example, the present in each vehicle ignition switch, with the vehicle and the OBU in Operation set. By means of a radio device 5, the OBU 2 establishes a radio link 6 to a background system 7 of a toll system. The radio link is made in the illustrated embodiment via a cellular network 13, for example, a GSM network.

In FIG. 2 are subcomponents of the FIG. 1 in a schematic representation in turn shown with their individual subcomponents. The power supply network 3 of the vehicle 1 is connected via the ignition switch 4 to the OBU 2. Thus, the operating times of the vehicle 1 with the operating times of the OBU 2 are congruent. The OBU 2 is connected by means of a bidirectional connection to a device 8 for determining a time for the independent establishment of a connection. This records the operating times by means of an operating time determination device 9 and stores these "operating time values" in a memory device 10. The memory device 10 accumulates these values until a predetermined number of values are stored in the memory device 10. Then, according to a "first-in-first-out" methodology, the removal of the oldest operating-time values in the time-domain of the storage takes place from the memory device 10.

Furthermore, the device 8 for determining the connection establishment time comprises a time point calculation unit 11. This first determines, using the operating time values stored in the memory device 10, a statistical value for a statistically expected travel time of the vehicle 1 and thus also the operating time of the OBU 2 In the present example, the statistical value is calculated as the arithmetic mean of n previous operating time values. In order not to distort the statistical value by extreme values that do not represent the mass of the operating time values, the values of the shortest and the values of the longest operating periods are excluded from the calculation of the statistical value. On the basis of the mean value, which represents the expected operating time, a time window is then determined relative to the start time of the current operating phase, in which the time of connection should be. With the help of a random number generator 12, an arbitrary time is selected within this time window.

The device 8 for determining the connection time with the background system 7 then transmits to the OBU 2 the information about the determined time. With the receipt of this information, the OBU 2 establishes the connection at the time determined independently. The OBU further comprises a toll collection device 20. This records during the operation of the OBU 2 and the vehicle 1 the tolled roads traveled by the vehicle 1. After a successful connection establishment with the background system 7, the OBU transmits this collected information to the background system of the toll system by means of a transmission device 2b. The OBU receives control data from the background system 7 via a receiving device 2c arranged in the OBU 2. Thus, for example, a system administrator of the background system can transmit calculation bases relating to the calculation of the time of connection establishment to certain or to all OBUs.

In the FIG. 2 the device 8 is shown spatially separated from the OBU 2. However, the device 8 can also be integrated without restriction in its function in the OBU 2. The illustrated variant with a device 8 arranged outside the OBU 2 is advantageous, for example, for retrofitting actions on OBUs 2 already manufactured and mounted in vehicles 1.

In FIG. 3 an exemplary frequency distribution of start-of-operation events N _B of toll vehicles 1 over the course of 24 hours of a normal working day is shown. Show this FIG. 3 the problem of peak loads, which are triggered by OBUs 2, which do not determine the time for independent establishment of a connection with the background system 7 by the method according to the invention, but establish the connection with the background system 7 after the start of operation of the OBU 2.

Starting at 6:00 am, there is a sharp increase in the start of trip events. This results from the relatively simultaneous start of travel of all vehicles 1 at the beginning of a working day. During the morning this value drops significantly. This does not mean that fewer vehicles are involved at this time, but only means that the "start of journey" event is now mainly caused by local traffic. This is distributed over the morning. Due to the long-distance traffic hardly an event is produced here. At noon, a break-in, followed by a tip to follow. This is not as pronounced as the peak load on the morning of the working day at 6:00 clock. At the end of a working day, the curve of the frequency distribution of the start of journey events further flattens.

If the OBU 2 communicates with the background system 7 triggered by the event indicated here, then the load of the communication network used to establish the connection, for example the mobile radio network, corresponds to as well as the burden of the background system 7 even this graph.

The in the FIG. 4 shown distribution curve shows a statistical frequency distribution of the average operating time t _{B of} an exemplary set of vehicles 1. Thus, it can be seen that the driving time of a vehicle 1 ranges from very short trips mostly in local transport to very long trips mostly in long-distance traffic. The values plotted on the vertical axis in the graph represent the number N _{F of} the vehicles with the respective average operating time t _B.

FIG. 5 shows in comparison to FIG. 3 exemplifies the effect of the method according to the invention in the course of a normal weekday. By the inventive consideration of the previous operating times of the OBU 2 in the determination of the time to establish a connection of the OBU 2 with the background system 7 is carried out a significant reduction of the load during the in FIG. 3 indicated peak load times at 6:00 and around noon. In addition, there is a distribution of the burden on the otherwise low-load times. The number N _V of the connecting receptacles for in each case the same time of the working day is more evenly distributed over the day as at a distribution according to FIG. 3 ,

FIG. 6 shows an example of a schematic sequence of the method according to the invention. In this case, a start of operation marks the starting point of the method in step I. In step II then takes place a determination of the duration of the last trip on the basis of previously stored events "start of journey" and "end of travel". The determined last operating time value is passed in step III of the operating time determination device 9 to the memory device 10 for the purpose of storage. The time calculation unit 11 determines in step IV from the currently stored operating time values the arithmetic mean value and calculates in step V therefrom the time for a connection establishment in the course the current operating phase according to the above-explained rules. In step VI, a timer is then set, which initiates the connection recording at the time determined. Finally, in step VII, the connection is established. If the current operating phase is terminated before the connection is established, the method is carried out again after the resumption of operation and establishes a connection in the next operating phase.

The FIGS. 7 and 8th show examples of vehicles with short service lives ( FIG. 7 ) and with long service lives ( FIG. 8 ), which results are achieved for a value set of operating periods. The example calculations in the FIGS. 7 and 8th use the exclusion of maximum and minimum values, which excludes extreme values, which are not representative of the vehicle, from averaging. The time window used is the third quarter of the average operating time determined. Within this time range, a random equal distribution is followed by a random determination of the time for establishing a connection.

The results from the exemplary calculations are in graphical form in the FIG. 9 shown. The arithmetic mean values t _B , _k , t _B , _{l of} the operating times for the vehicle with the short (index k) and with the long (index 1) operating time are shown in dashed form. The time windows Z _k , Z _{l of} the third quarters of the average operating times t _B , _k , t _B , _l selected within these operating times for connection establishment are shown in solid lines.

Finally, it should be pointed out that the description of the invention and the exemplary embodiments are in principle not restrictive with regard to a specific physical realization of the invention and thus can be modified in various ways without departing from the scope of the invention. For a specialist it is particularly obvious that the invention as a heterogeneous system partially or completely in soft and / or hardware and / or on a plurality of physical products - in particular also computer program products - can be distributed distributed.

Claims (14)

1. Method for determining a time point for autonomously establishing a connection from an on-board unit (2) which is arranged in a vehicle (1) and operated in a phased manner to a background system (7) of a toll system, wherein the time point for establishing the connection during a current operating phase is determined as a function of a duration of a preceding operating phase of the on-board unit (2).
2. Method according to claim 1,
   wherein the operating phases of the on-board unit (2) include at least the travel times of the respective vehicle (1).
3. Method according to one of the claims 1 or 2,
   wherein a plurality of preceding operating phases are taken into consideration when determining the time point for autonomously establishing the connection.
4. Method according to claim 3,
   wherein a statistical value is calculated from the temporal duration of the preceding operating phases and this statistical value is used to determine the time point for autonomously establishing the connection.
5. Method according to claim 4,
   wherein the arithmetic mean value of the temporal duration of the operating phases is calculated as a statistical value.
6. Method according to claim 4 or 5,
   wherein a predetermined number of maximal values and minimal values of the temporal duration of the operating phases is excluded from the calculation of the statistical value.
7. Method according to one of the claims 1 to 6,
   wherein the time point for autonomously establishing the connection is randomly determined according to a distribution which is dependent on the duration of the preceding operating phase(s).
8. Method according to one of the claims 1 to 7,
   wherein the time point for autonomously establishing the connection is situated within a time window (Z_k, Z_l) within the current operating phase, said time window (Z_k, Z_l) being determined as a function of the duration of the preceding operating phase(s) by means of a rule which is or can be predetermined.
9. Method according to claim 8,
   wherein the time point for autonomously establishing the connection is situated in the time window according to a random uniform distribution.
10. Method according to one of the claims 1 to 9,
    wherein the time point for establishing the connection is determined as a function of a current time of day and/or a current calendar date and/or a current position and/or travel route.
11. Method according to one of the claims 1 to 10,
    wherein the on-board unit (2) establishes a connection to the background system (7) of the toll system via a mobile radio network (13).
12. Device for determining a time point for autonomously establishing a connection from an on-board unit (2) which is arranged in a vehicle (1) and operated in a phased manner to a background system (7) of a toll system, comprising

    - a device for ascertaining an operating time (9),

    - a storage device (10) for storing the values of the temporal duration of the operating phases of the on-board unit (2),

    - a time-point calculation unit (11) for calculating the time point for establishing the connection as a function of a duration of a preceding operating phase of the on-board unit (2).
13. Vehicle-on-board unit (2) for a toll system, comprising a device according to claim 12 for determining a time point for autonomously establishing a connection from the on-board unit (2) to a background system (7) of the toll system.
14. On-board unit according to claim 13, comprising

    - a toll recording device (2a),

    - a send device (2b) for sending recorded toll data to the background system (7), and

    - a receive device (2c) for receiving control data from the background system (7).

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