WO1999024952A1 - Method, system and devices for collecting traffic data - Google Patents

Abstract

The invention concerns a method and a system for collecting data concerning traffic on a road network via a telecommunication system, which consists in determining the real positions of the vehicles by a plurality thereof and, in particular, via a mobile radio network (4) in conformity with the GSM standard, by means of short messages (3) transmitted to a traffic data central unit (5) comprising a short message service centre (50) capable of operating special services (51, 52). A special service (51) of the short message service centre (50) processes the received positions and computes the average speeds for predetermined road sections, which are stored in a data bank, in the form of individual time series for the respective corresponding predetermined road sections. Another special service (52) of the short message service centre (50) evaluates the time series of the average speeds for the predetermined road sections, taking into account the traffic jams and supplies to clients corresponding data concerning bottlenecks in the traffic.

Description

 Method, system and devices for collecting traffic data

The present invention relates to a method for collecting traffic data from a road network via a communication system. In particular, the present invention relates to a method for collecting traffic data from a road network via a mobile radio network, at least the current positions of a plurality of motor vehicles being transmitted to a traffic data center for processing.

In the prior art, various methods and systems for collecting traffic data are known which are based on sensors which are installed at certain primary points in the road network. Traffic data in these processes and systems are limited to the primary locations and if better coverage is required, the installations required in many locations and, above all, the maintenance of the numerous sensors quickly lead to high costs.

There are also known solutions that are expensive

Do not install many sensors and instead record traffic data from vehicles. A traffic information system (Traffic Information System), in which information about traffic jams or accidents is collected by a device installed in a vehicle, is described in EP 0 720 137 A2. In addition to the possibility of manually entering information relating to traffic jams, accidents and weather, the device described therein comprises an automobile navigation system for determining the position, a laser radar device for determining the number, the speed and the shape of vehicles, and traffic jam information and accident information are generated on the basis thereof. Various information collected by the vehicle is transmitted to a control center from a repeater, from where it is transmitted back to vehicles after processing by the control center.

A traffic monitoring system with reduced

Communication requirements (Traffic Monitoring System With Reduced Communications Requirements) is described in WO 95/14292. In this system, there are calibration vehicles that, equipped with a differential GPS (Global Positioning System), record average speeds of short time intervals along with the corresponding time and position information during longer calibration phases along selected routes. The recorded data from all calibration vehicles are loaded into the computer of a control center and processed there statistically in order to obtain a data baseline with average speed patterns. Depending on this data baseline, probing vehicles are used which transmit their speed by means of a radio telephone if it deviates from the data baseline by a predefined value.

WO 96/30884 describes the transmission of position signals from mobile units (Communication of Position Signals from Mobile Units), which suggests automatically executed calls in a mobile telephone network such as the GSM (Global System for Mobile Communication) network for the transmission.

It is the object of this invention to propose a new and improved method and system for collecting traffic data, which in particular is not dependent on sensors permanently installed in the road network.

According to the present invention, this aim is achieved in particular by the elements of the characterizing part of independent claims 1, 11 and 17. This goal is also achieved by the system according to independent claim 23. More beneficial

Embodiments are also apparent from the dependent claims and the description.

In particular, these goals are achieved by the invention in that the current positions of motor vehicles in the road network are continuously and directly transmitted to a traffic data center where they are collected and processed to store and update traffic data in a database.

With the present method, the position of a motor vehicle located in the road network is preferably determined by means of a differential global positioning system (GPS) with which the motor vehicle in question is equipped. According to the invention, the current positions determined in this way are transmitted from the motor vehicle to a traffic data center by means of short messages (Short Message Service, SMS) via a mobile radio network, which preferably works according to the GSM standard.

The traffic data center preferably comprises a short message service center which is equipped such that it can carry out special services which are ordered by means of short messages from subscribers in the mobile radio network, preferably in accordance with the method which is described, inter alia, in patent EP 0689 368 B1. In this procedure, applications in the service center communicate with applications on a SIM (Subscriber Identification Module) card by means of short messages via a cellular network according to the GSM standard. A software filter for short messages received allows special services such as the exchange of files, instructions and programs between the service center and a SIM card to be carried out. It is important to clarify here that the SIM card used in EP 0689 368 B1 is not decisive for the present invention, but that its features, in particular the software filter for executing special services, can also be implemented in another form known to the person skilled in the art .

The determined current position is transmitted within the short message, after the header of the short message and after a second header that indicates the special service. The positions received in a short message by the traffic data center are temporarily stored by the special service in the Short Message Service Center. In a further step, this service uses average values for position and time values for predefined road segments calculates which are saved in a database in individual time series for the corresponding predefined road segments. In one variant, in addition to the current position, the current vehicle speed is also determined and transmitted, with the result that the average speeds for predefined road segments are calculated in a correspondingly simplified manner.

The transmission of the current position of motor vehicles by means of short messages has in particular the advantages of short transmission times and low transmission costs.

An embodiment of the present invention is described below using an example. The example of the execution is illustrated by the following enclosed figures:

1 shows an overview diagram with a section of the segmented road network, a motor vehicle, the mobile radio network, and the traffic data center.

FIG. 2 shows a block diagram of the device for the motor vehicle, which comprises components for determining and transmitting the position.

3 shows the structure of a short message for the transmission of the determined position.

FIG. 4 shows a first variant of a flow chart, which illustrates the determination of time series with average speeds of road segments.

FIG. 5 shows a second variant of a flow chart, which illustrates the determination of time series with average speeds of road segments. The reference number 1 relates to a road section of the road network which, in this example, is divided into the road segments 10a, 10b, 10c and 10d. The length of the road segments can be freely defined, but is preferably fifty meters to several kilometers. A variable segment length, which depends, for example, on the average traffic density, is also possible. A motor vehicle 2 is located in the road segment 10a and moves toward the next road segment 10b in the direction of the arrow. In this example, the road has two lanes, for example with a different direction of travel. However, it does not matter to the invention whether it is a single or multi-lane road or a freeway.

Inside the motor vehicle 2 there is a device 20, the components 200, 201, 202, 203 and 204 of which are explained in more detail below.

Component 200 includes position determining means, in this exemplary embodiment a differential global positioning system, which allows the position to be determined with an accuracy of approximately one meter.

The components 201 and 202 contain transmission means which make it possible to communicate in a mobile radio network 4 in accordance with the GSM standard (GSM component 201) and to transmit short messages in this GSM network (SMS component 202).

In a preferred variant, the position of the motor vehicle 2 is periodically transmitted to the traffic data center 5. Within this period, the position of motor vehicle 2 is first determined using GPS component 200. The value of the determined position is passed to the SMS component 202, where it is inserted into the short message 3 (FIG. 3). The short message 3 is constructed in such a way that the field 31 contains the standard header of the short message, that the field 32 contains a further second header which shows the recipient the special service - in this case the collection of traffic data - and that the field 33 contains the value of the specific position of motor vehicle 2. The short message 3 thus constructed is then sent by the GSM component 201 to the traffic data center 5 via the mobile radio network 4 within the same period.

The traffic data center 5 comprises a short message service

Center (SSC) 50 which, in addition to the functionality for handling standard short messages, has the functionality to recognize special services, which are specified in the second header 32, and the content of the short messages to the corresponding applications for executing the corresponding special services - in this case the application for the collection of traffic data 51 - pass on.

An embodiment of the method according to the invention will now be described with the aid of the attached FIG. 4. In a first step 601, the application determines the reception time for the collection of traffic data 51 and takes the value of the current position transmitted by the motor vehicle 2 from the field 33 during step 602.

In step 603 it is checked whether a position has already been received by the transmitter in question, in this case motor vehicle 2. In the event that a position value has not yet been received from the transmitter in question, the process continues with step 607 in which the time determined in step 601, the position value obtained and the identification of the transmitter are stored. In the event that a position has already been received by the transmitter in question, the average vehicle speed of the corresponding motor vehicle is calculated in step 604 from the previous and new time and position values. In step 605, the road segment corresponding to the newly transmitted position, in this case 10a, is determined. In step 606, the time determined in step 601 and the calculated average vehicle speed are stored for this specific road segment.

After the time determined in step 601, the received one

Position value and the identification of the transmitter are stored in step 607 was checked in step 608 whether a new average speed should be calculated for the particular road segment. In one variant, this is done by comparing the time determined in step 601 with a periodically incremented target time. In another variant, this decision depends on the number of average vehicle speeds stored for the relevant road segment since the last average calculation. If no new calculation is necessary, the processing of the received short message 3 ends in step 611. Otherwise, the average speed for the relevant road segment is calculated in step 609 (if the variant allows this step to be carried out without newly stored average vehicle speeds, this is carried out for this Given the existing average speed for the relevant street segment as a result). In step 610, the average speed calculated for the street segment together with the current time is stored in a database as a new value in a time series for the corresponding street segment. The processing of the received short message 3 then ends in step 611.

The previously described method for collecting traffic data has proven to be advantageous since the traffic data stored in the database is continuously and directly updated by the motor vehicles in the road network. In addition to non-commercial passenger vehicles, vehicles of public transport, such as buses, or commercial transport, such as taxis or trucks, can also be included, for example, by equipping them with a corresponding device (20) for collecting traffic data.

In a variant, the device 20 also has a clock 203, which is used to determine the current time when determining the current position of the motor vehicle, which is transmitted in addition to the position in the short message 3. Accordingly, in this variant, this transmitted time is taken from the short message 3 in the first step 601, instead of the reception time being determined. This variant has the advantage that the Calculation of the average vehicle speed of a motor vehicle cannot be falsified by the transmission times of short messages.

In another variant, the current position of the motor vehicle, which is determined at the beginning of the period mentioned, is determined a second time within this period after a short predefined period of time, for example three seconds, and transmitted in the short message 3 to the traffic data center. The determined current positions are transmitted in two different short messages, which follow one another within the short predefined time period, with the corresponding, successively determined current positions. In another embodiment of this variant, the successively determined current positions are transmitted to the traffic data center in a common short message. Both embodiments of this variant have the advantage that the calculation of the average vehicle speed of a motor vehicle is simplified by the application for the collection of traffic data, since the time difference between the current positions of a motor vehicle successively determined in one period always corresponds exactly to the short, predefined time period.

In a further variant, the device 20 also has means 204 for determining the speed of the motor vehicle. Thus, in addition to the current position of the motor vehicle, the current speed of the motor vehicle can also be determined and transmitted in addition to the current position in the short message 3. This eliminates the need to calculate the average vehicle speed of a motor vehicle using the application for the collection of traffic data 51. Accordingly, in a first step 701 the application 51 determines the reception time (or takes the time from the short message if this variant is determined and transmitted by the motor vehicle in this variant) ) and in step 702 takes short message 3 from the current vehicle speed and current position transmitted by motor vehicle 2 (field 33). In step 705, the road segment corresponding to the newly transmitted position is in this Case 10a, determined. In step 706, the time determined in step 701 and the received vehicle speed are stored for this specific road segment. Step 708 checks whether a new average speed should be calculated for the particular road segment. In one variant, this is done by comparing the time determined in step 701 with a periodically incremented target time. In another variant, this decision depends on the number of vehicle speeds stored for the relevant road segment since the last average calculation. If no new calculation is necessary, the processing of the received short message 3 ends in

Step 711. Otherwise, the average speed for the relevant road segment is calculated in step 709 (if the variant allows this step to be carried out without newly stored average vehicle speeds, in this case the already existing average speed for the relevant one

Road segment given as a result). In step 710, the average speed calculated for the road segment together with the current time is stored in a database as a new value in a time series for the corresponding road segment. Thereafter, the processing of the received short message 3 ends in step 711. This variant has the additional advantage that the calculation of average vehicle speeds in the traffic data center is omitted and therefore, especially in cases where many motor vehicles are equipped with a corresponding device (20) Collection of traffic data are included, is significantly relieved.

In addition to the application for the collection of traffic data 51, the traffic data center 5 also includes other applications 52, which also perform special services requested by means of short messages 3. For example, application 52 provides specific traffic information, such as traffic congestion information, on request. In this example, the application 52 evaluates the time series of average speeds of road segments created by the application for the collection of traffic data 51 and stored in a database with regard to traffic congestion. In this evaluation there is a traffic jam indicated by a significant reduction in the average speed in one or more contiguous road segments. An interested customer, for example in a motor vehicle 2, can, for example, request traffic jam information from a specific street or area or for the streets between a starting point and a destination. These special services are ordered by means of short messages 3 via the mobile radio network 4 to the traffic data center, preferably as described above, according to the method which is represented, inter alia, in patent EP 0689 368 B1. It is readily apparent to the person skilled in the art that there are various possibilities for providing the customer in the motor vehicle 2 with means for requesting such special services and means for presenting the resulting information, but this is not the subject of this invention.

Although this was not described in this exemplary embodiment, it is entirely possible to have a plurality of traffic data centers which are connected, for example, to one another and can share and exchange traffic data with one another.

In particular, it is also important to emphasize that the traffic data for the road segments need not be limited to time series of average speeds, but rather that other traffic information can also be determined, transmitted, received, processed, stored and distributed. For example, additional information such as road temperature, air temperature or visibility (determined, for example, by detecting the presence and density of fog) in field 34 can be transmitted to the traffic data center for further use.

With regard to the determination of the current position of a motor vehicle 2, it is also particularly important to clarify that this does not have to be carried out exclusively by means of the Global Positioning System (GPS), but that this can also be done using another position determination means, for example in particular using a terrestrial positioning system ( TPS) can be performed.

Claims

Expectations 1. A method for collecting traffic data from a road network via a communication system, the current position of a motor vehicle being determined by position determining means with which at least certain motor vehicles on the road network are equipped, the determined positions by transmission means with which at least certain motor vehicles are equipped , are transmitted to a traffic data center via the communication system, wherein the said transmitted positions are received and temporarily stored by the traffic data center, characterized in that the said communication system is a mobile radio network (4) via which the specific positions of a large number by means of special short messages (3) from certain motor vehicles to at least one named traffic data center (5) that said traffic data center (5) contains the special short messages (3) mentioned above n distinguishes other short messages and determines traffic information from the transmitted positions. 2. The method according to the preceding claim, characterized in that said determined traffic information contains average speeds for predefined road segments. 3. The method according to any one of the preceding claims, characterized in that said average speeds are stored in a database as individual time series for the corresponding predefined road segments. 4. The method according to any one of the preceding claims, characterized in that the position determining means comprise a differential global positioning system (200) or a terrestrial positioning system. 5. The method according to any one of the preceding claims, characterized in that the short message (3) is structured such that The standard header of the short message (31) is followed by a second header (32) for the identification of special services, behind which the specific position (33) to be transmitted to the traffic data center (5) is located. 6. The method according to the preceding claims, characterized in that in addition to the current position of the motor vehicle (2) in question, the current speed of the motor vehicle (2) is determined and transmitted. 7. The method according to the preceding claims, characterized in that the motor vehicle (2) additionally determines and transmits further information. 8. The method according to the preceding claim, characterized in that the determination and transmission of additional further information by the motor vehicle (2) includes in particular the determination and transmission of the street temperature. 9. The method according to claim 7, characterized in that the determination and transmission of additional additional information by the motor vehicle (2) includes in particular the determination and transmission of the air temperature. 10. The method according to claim 7, characterized in that the determination and transmission of additional additional information by the motor vehicle (2) includes in particular the determination and transmission of the visibility. 1 1. Device (20) for a motor vehicle (2), characterized in that it has at least position determining means (200) for determining the current position of the motor vehicle in question and transmission means (201, 202) for transmitting said position by means of short messages (202) via a mobile radio network ( 4) to a traffic data center (5). 12. The device (20) according to the preceding claim, characterized in that the position determination means contain a differential global positioning system (200) or a terrestrial positioning system. 13. The device (20) according to one of claims 11 or 12, characterized in that it additionally comprises means for determining the current speed of the motor vehicle (204) and its transmission to the traffic data center (4). 14. The device (20) according to one of claims 11, 12 or 13, characterized in that it additionally has means for determining the Street temperature and their transmission to the traffic data center (4). 15. The device (20) according to one of claims 11, 12 or 13, characterized in that it additionally comprises means for determining the air temperature and its transmission to the traffic data center (4). 16. The device (20) according to one of claims 1 1, 12 or 13, characterized in that it additionally comprises means for determining the visibility and transmitting it to the traffic data center (4). 17. Device for a traffic data center (5) which has access to a database and which is connected to a mobile radio network (4), characterized in that it comprises the following means: Means for receiving and temporarily storing special short messages (3), Means for determining positions of certain motor vehicles from the temporarily stored short messages, and Means for determining traffic information from the specific positions. 18. Device for a traffic data center (5) according to the preceding claim, characterized in that it additionally comprises the following means: Means for processing the temporarily stored positions, average speeds being calculated for predefined road segments, Means for storing the calculated average speeds mentioned as individual time series for the corresponding predefined road segments in the database mentioned. 19. Device for a traffic data center (5) according to the preceding claim, characterized in that it additionally has means for receiving, temporarily storing and processing the determined by a large number of certain motor vehicles on the road network and by means of special short messages (3) about the said Cellular network (4) transmitted current speed includes. 20. Device for a traffic data center (5) according to one of claims 18 or 19, characterized in that it additionally has means for receiving, temporarily storing and processing the data determined by a large number of certain motor vehicles on the road network and by means of special short messages (3) road temperature transmitted via said mobile radio network (4). 21. A device for a traffic data center (5) according to one of claims 18 or 19, characterized in that it additionally has means for receiving, temporarily storing and processing the data determined by a large number of certain motor vehicles on the road network air temperature transmitted by means of special short messages (3) via said mobile radio network (4). 22. Device for a traffic data center (5) according to one of claims 18 or 19, characterized in that it additionally has means for receiving, temporarily storing and processing the data determined by a large number of certain motor vehicles on the road network and by means of special short messages (3). range of sight transmitted via said mobile radio network (4). 23. System for performing the method according to claims 1 to 10 by means of the devices according to claims 11 to 22 via Cellular network (4).