EP2186077B1 - Method and device for controlling traffic flow - Google Patents

Description

The invention relates to a method and a device for controlling the traffic flow. It is provided that the information about the time until switching a traffic light to another traffic light phase, i. in particular red, yellow or green, is used to give the driver of a vehicle a speed recommendation for approaching the traffic light. A traffic light in the sense of the invention is any traffic light system that gives instructions to vehicles in traffic.

In such traffic light phase assistants, therefore, the information about the duration until the change of the traffic light to the next traffic light phase, for example from green to yellow to red, is used to indicate to the driver at which speed he has a green wave, ie whether he is still at green, the traffic light can happen or this will switch to red before and forces him to stop. In order to realize this function of the traffic light phase assistant, it is necessary for the vehicle to know the switching times between the individual phases of the traffic light. Typically, for this purpose, a direct communication between the traffic light and the vehicle is used, via which the switching times is communicated. Here, in particular, the so-called Dedicated Short Range Communication (DSRC) for the application, ie a vehicle-to-infrastructure communication based on ad hoc networks.

However, there is the problem that these ad-hoc networks are often not built up fast enough or are not available for all vehicles depending on the hardware of each vehicle. In addition, the range of the communication is not sufficient to anticipate for a variety of subsequently passed traffic lights to give a total of these traffic lights speed recommendations.

The publication WO 03/077222 A (D1) discloses an automatic vehicle guidance method in which infrastructure data is wirelessly transmitted to the vehicle and commands for vehicle guidance are calculated from the infrastructure data.

The publication US2003 / 128135 A1 discloses an apparatus and method for remotely controlling a traffic control device.

Object of the present invention is therefore to achieve an improvement in the determination of the speed recommendation, with a total of more vehicles to be achieved.

This object is achieved with the features of claims 1 and 10. In the method proposed according to the invention, the position and the switching times of a traffic light for a plurality of traffic lights are stored in a database with the function of a server. Via a mobile radio communication connection, these data (position and switching times) can be called up by a motor vehicle, so that the driver of the vehicle is given the speed recommendation using this information, ie in particular switching times and / or position of the traffic light. By using a preferably central database for storing the switching times of the traffic light phases, it is possible, the switching times of this traffic light without a direct Use radio connection to this special traffic light for the calculation of speed recommendations of a traffic light phase assistant. Since the vehicles already often have or will have mobile radio communication in the future, for example in order to realize an ecall (automatic emergency call), wherein the mobile radio communication devices are connected, for example, to a driver assistance system, this can be done without the need for a new hardware deployment a variety of vehicles can be achieved. In addition, the central management of the switching times of the traffic lights offers an advantage in traffic planning, since these data can also be used in the development of traffic concepts and they can enter into simulations.

According to the invention, provision is made in particular for the position of the vehicle relative to the traffic light to be taken into account for the speed recommendation to the driver, in particular to determine whether within the permitted maximum speed, which is transmitted as an additional parameter with the position and the switching times of the traffic light can, a so-called green wave for the driver can be realized, ie that the driver is not forced to stop when the traffic light is reached.

According to a further development of this method variant, the position of the vehicle and the position of the traffic light can be taken into account in a digital road map in which, for example, the maximum permissible speeds are also noted. In this case, this speed would have are not transmitted in the data transfer. In addition, this method variant allows a prediction of whether a traffic light is located in the traffic route of the vehicle, and the retrieval of the switching times to this traffic light in advance by the vehicle.

According to the invention, the database for this is preferably sorted in such a way that the retrieval of the data takes place on the basis of the position data of the traffic light and / or the vehicle, i. the traffic lights in the database are sorted according to preferably global coordinates of a position or navigation system in order, for example, to transmit the switching times of the coming traffic light and, if appropriate, the subsequent traffic lights, based on transmitted vehicle positions.

A further improvement of the prediction accuracy can be achieved if navigation data of the vehicle is taken into account in the speed recommendation. In the case of a travel route entered in a navigation system, this can be done, in particular, by taking into account additional traffic lights on the route for determining the speed recommendation, and by reaching a green wave for several consecutive traffic lights even when departing from a main traffic route. For major traffic routes, the traffic light phases are often preconfigured to set a green wave. Without an entered route, the navigation data of the vehicle can also be interpreted to determine a more likely route along a route and to issue a speed recommendation for this purpose. If in determining the speed recommendation not only the next, but also the following traffic lights are taken into account on a longer journey, it may be useful according to the invention to consider the upcoming and possibly the next traffic light with a higher weighting. It is thus achieved that an optimized speed recommendation is given for the traffic lights immediately following, since it is not predictable, especially in cities, whether obstacles will occur on the further travel path, which in any case force them to deviate from the speed recommendation.

In a further development of the method proposed according to the invention, it can further be provided that the current or a currently averaged speed of the vehicle is taken into account in the speed recommendation, for example by a speed corridor lying around this current or currently averaged speed. As a result, a feel-good speed of the driver or a traffic situation in determining the speed recommendation can already be taken into account.

In order to avoid inaccuracies due to time tolerances of real-time clocks, it is proposed according to a particularly preferred embodiment of the invention to use as reference time the time base of a preferably global positioning or navigation system. Such a positioning or navigation system may in particular be the GPS system or the future European satellite positioning system Galileo or comparable systems based on satellite signals under Use an accurate time base to perform location fixes.

In order to keep the database proposed according to the invention up-to-date, it is possible in particular for dynamic adaptation of the traffic light phases, i. the time until a change of the traffic light phase, also a dynamic update of the database. This can preferably be implemented by means of a mobile radio connection or especially in cities wired communication networks such as bus systems. This communication options between the traffic light and the database can be used according to the invention in parallel for maintenance tasks or the transmission of fault messages.

According to an advantageous implementation, it is proposed that the mobile radio communication connection is realized by means of 2 G, 2.5 G, 2.75 G, 3 G and / or 4 G mobile radio networks, which provide sufficient data transmission capacities for the data to be transmitted. However, the invention is not limited to the known mobile communication solutions, but can in principle be implemented with other wireless communication solutions that allow secure data transmission from a central server with database to mobile vehicles and / or traffic lights.

In order to reduce the number of radio transmissions, it can be provided according to a particularly advantageous variant of the method that during the transmission of the switching times for the upcoming traffic light and the switching times for one or several following traffic lights are transmitted with the same, in particular in each case together with the position data. Thus, all information is available in the vehicle and can be taken into account by the traffic light phase assistant without further radio communication in determining the speed recommendation.

The invention also relates to an apparatus for controlling the traffic flow for use with a traffic light phase assistant according to the features of claim 9. The traffic light phase assistant used with the apparatus is adapted to the driver based on information about the time until the traffic light turns to another traffic light phase to give a vehicle a speed recommendation for approaching the traffic light, wherein a database is provided, in which the position and the switching times of a traffic light are stored, and a mobile communication device is connected to the database, which queries the position and the switching times a traffic light via a mobile phone connection at regular intervals and / or a change in the switching times to communicate these switching times the data server with the database, so that they can be kept dynamically updated by a continuous update of the switching times.

The database is preferably set up so that the dynamically changing switching times are recognized in the database and provided with an identifier. The device according to the invention can be designed both for connection to a traffic light phase assistant and also contain an integrated traffic light phase assistant.

According to the invention, the device is provided in particular in a data server of a database in which the position and the switching times of a traffic light for a plurality of traffic lights are stored. Switching times represent the switching times between the traffic light phases (for example red, yellow, green), it also being sufficient for carrying out the method according to the invention to take into account only the switching times for the phases red and green, since the yellow phases are very short and at one Speed recommendation does not necessarily have to be considered. With the database according to the invention a mobile communication device is connected to a query of the

Position and the switching times of one or more traffic lights over a cellular connection allows. The database or the data server on which the database is installed can be set up in a function as a control device, in particular for carrying out the method described above or parts thereof.

According to a preferred embodiment of the device, the data server is connected to a receiver of a particular global positioning or navigation system and is adapted to determine the time base of the positioning or navigation system. This time base can be used as a reference time to avoid having each traffic light know the reference time itself and must maintain it exactly.

To set and / or dynamic update, for example, changes in switching times, a traffic light for carrying out the method according to the invention in predetermined intervals, the time switching points of the individual phases transmitted to the data server, the time between time switching point and transmission is recorded and transmitted. With this information, the data server can then transform the switching time to the reference time and store it based on this time base. Due to the short time between a switching time of a phase change of the traffic light and the transmission to the server occurs here no significant inaccuracy. However, this procedure can be dispensed with if the traffic light knows the reference time base itself, for example because it is also with a receiver of the positioning or navigation system or the reference time is synchronized at regular intervals over a communication link. Partly, a program is also installed in traffic light controls that specifies the switching times. Then it is also possible, for example, to transfer the program and its start time to the database. Based on this, the database can calculate the switching times for this traffic light and store it explicitly or as a calculation rule in the database. Therefore, it is basically sufficient if the program and the start time are sent only once, especially when starting the operation. For synchronization, however, it is advisable to retransmit the start time and possibly also the program at fixed time intervals. A suitable period is about 24 hours, ie a once-daily synchronization.

In a further development of the invention, the device can also have a mobile transmitting and receiving device with an interface to a traffic light phase assistant. This communication device is preferably mounted in a vehicle and may represent a unit with the traffic light phase assistant, which controls the communication device. Of course, a control device that is separate from the traffic light phase assistant can also be provided, so that the device can be operated independently of the traffic light phase assistant and only provides it with the required information. In this last variant, the device proposed according to the invention is particularly suitable for retrofitting existing traffic light phase assistants.

In a comprehensive embodiment of the device according to the invention, the transmitting and receiving device and / or the traffic light phase assistant are integrated into a driver assistance system, which also has other functions and is designed in particular as a computer, for example with a programmable microprocessor or comparable arithmetic unit. In this case, the mobile part of the device according to the invention which is attributable to the vehicle can also be designed as a computer program product which sets up the processor of the driver assistance system to carry out the method described above and the components present in the vehicle, in particular the transmitting and receiving device and the traffic light phase assistant uses inventive way.

Further advantages, features and applications of the present invention will become apparent from the following description of an embodiment and the drawing. All described and / or illustrated features alone or in any combination form the subject matter of the present invention, also independent of their summary in the claims or their back references.

Fig. 1

schematisch eine Ausführungsform der erfindungsgemäßen Vorrichtung bei Durchführung des vorgeschlagenen Verfahrens.

It shows:

Fig. 1

schematically an embodiment of the device according to the invention in carrying out the proposed method.

In Fig. 1 a device 1 for controlling the traffic flow is shown, which has a data server 2 with a database in which the position P and the switching times Si of a traffic light 3 for a plurality of traffic lights 3 are deposited, wherein Fig. 1 only one record (P, Si) of a traffic light 3 is shown. Connected to the database 2 of the data server is a mobile radio communication device 4, which makes it possible to query the position P and the switching times Si of traffic lights 3 via a mobile radio connection 5. The mobile radio connection 5 can be, for example, one of the typically commercially available mobile radio networks of the generations 2 G, 2.5 G, 2.75 G, 3 G or 4 G, which enable transmission of data at different transmission speeds.

Frequently, vehicles 6 are already equipped with corresponding mobile transmitting and receiving devices 7. This transmitting and receiving device 7, which also performs a plurality of data transmissions from the vehicle 6 for other functional units, has an interface to a traffic light phase assistant 8, which is implemented in the vehicle 6. The traffic light phase assistant 8 is set up to give the driver of the vehicle 6 a speed recommendation for approaching the traffic light 3 on the basis of information about the time until switching of the traffic light 3 (switching times Si) to another traffic light phase, so that it is possible during the traffic light Green phase reached and at the traffic light 3 does not have to stop. For this purpose, it is controlled by the traffic light phase assistant 8 queried in the data server or the database 2, which switching times Si are to be expected. The traffic light 3 is thereby about their position data P identified, which knows the car from a positioning or navigation system 9 also associated with the mobile transceiver.

The positioning or navigation system 9 also allows from the current position of the vehicle 6 and the position P of the traffic light 3 by the traffic light phase assistant 8 to give a very accurate speed recommendation for the approach to the traffic light 3, in which possibly even the current maximum speed or Road condition is taken into account.

As a common reference time, the time base of a global positioning or navigation system is used, which also uses the positioning or navigation system 9 in the vehicle 6. This may, for example, be the currently widespread GPS system, although other, for example, future systems such as the Galileo system come into question.

In order to set the switching times Si of the traffic light 3 to the common reference time, the device 1 has a receiver 10, which is in communication with the mobile radio communication device 4 and the data server or the database 2, of the positioning or navigation system, which is set up for the time base of the positioning or navigation system. Thus, the switching times Si transmitted by the traffic light 3, for example also by means of a mobile radio connection 5, can be found in the database 2 with the reference time valid in the entire system be filed. In this way, synchronization problems of different clocks in different components of the entire system are avoided by using the common time base.

Since traffic lights 3 often adjust their switching times also dynamically in response to a traffic flow, it is proposed that the traffic lights 3 communicate via the mobile radio connection 5 at regular intervals and / or a change in the switching times Si these switching times the data server with the database 2, so this can be kept dynamically updated by a continuous update of the switching times Si. In order to facilitate indexing in the system, dynamically changing switching times can be detected in the database 2 and provided with a flag which allows faster access to these switching times for a continuous update. This can be done for example by a special indexing of these switching times in the database 2.

With the present system, the switching times Si are stored in connection with the position P of a traffic light 3 for their identification in a preferably central database 2 and can there also without a direct ad hoc radio link between the traffic light 3 and the vehicle 6 via a mobile phone connection 5 are retrieved. Mobile communication devices with a mobile transmitting and receiving device 7 are often installed in vehicles 6, for example for a Ecall, so that can be used on existing communication technology. This is technically easier than building ad hoc network connections. In this way, the required information is available to a traffic light phase assistant 8 in a technically simple manner, without having to set up a direct radio communication connection between the traffic light 3 and the vehicle 6.

LIST OF REFERENCE NUMBERS

1

Device for controlling the traffic flow

2

Data server, database

3

traffic light

4

Mobile communication device

5

cellular Line

6

vehicle

7

Transmitting and receiving device

8th

Ampelphase Assistant

9

Positioning or navigation system

10

receiver

P

Position of a traffic light

Si

Switching times of a traffic light phase (i)

Claims (10)

1. A method for controlling a flow of traffic, in which information about a period of time before a set of traffic lights (3) changes to another traffic light phase is used to provide a driver of a vehicle (6) with a speed recommendation for approaching the traffic lights (3), wherein a database (2) is used to store a position (P) and change times (Si) of a set of traffic lights (3), and said position and change times can be retrieved by a vehicle (6) via a mobile radio communication link (5), and that the driver of the vehicle (6) is provided with the speed recommendation using this information, characterized in that dynamic adaptation of traffic light phases involves the database (2) being dynamically updated.
2. The method according to Claim 1, characterized in that a position of the vehicle (6) relative to the traffic lights (3) is also taken into account for the speed recommendation.
3. The method according to Claim 2, characterized in that the position of the vehicle (6) and the position (P) of the traffic lights (3) are taken into account in a digital roadmap.
4. The method according to Claim 2 or 3, characterized in that navigation data for the vehicle (6) are taken into account for the speed recommendation.
5. The method according to any one of the preceding claims, characterized in that a speed of the vehicle (6) is taken into account for the speed recommendation.
6. The method according to any one of the preceding claims, characterized in that a reference time used is a time base for a global positioning or navigation system.
7. The method according to any one of the preceding claims, characterized in that the mobile radio communication link (5) is effected using 2 G, 2.5 G, 2.75 G, 3 G and/or 4 G mobile radio networks.
8. The method according to any one of the preceding claims, characterized in that transmission of the change times (Si) for upcoming traffic lights (3) involves change times for one or more subsequent set(s) of traffic lights that are also being transmitted.
9. An apparatus for controlling a flow of traffic for use with a traffic light phase assistant (8), which is set up to take information about a period of time before a set of traffic lights (3) changes to another traffic light phase as a basis for providing a driver of a vehicle (6) with a speed recommendation for approaching the traffic lights (3), wherein a database (2) is provided which stores a position (P) and the change times (Si) of a set of traffic lights (3), and the one mobile radio communication device (4) is connected to the database (2) which allows the position (P) and the change times (Si) of a set of traffic lights (3) to be requested via a mobile radio link (5) at regular intervals of time and/or allows these change times (Si) to be communicated to the data server with the database (2) at regular intervals of time when the change times (Si) are altered so that they can be dynamically kept up to date by means of a continuous update of the change times (Si).
10. The device according to Claim 9, characterized in that the database (2) is set up such that the dynamically changing change times can be identified in the database (2) and provided with an identifier.

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