FR2843474A1 - Motor vehicle traffic information generation system, and motor vehicle navigation system, in which vehicles carry traffic information generating equipment and are linked in an ad-hoc network - Google Patents

Abstract

Method for generating road traffic information involves determination of local traffic information, based on a vehicle's own movements and displacements and on similar information received from vehicles in the vicinity equipped with similar traffic information generation equipment. The invention also relates to corresponding equipment for production of road traffic information, a system for production of road traffic information comprising a plurality of such information equipment units, a road navigation system and road navigation equipment.

Description

The present invention relates to a method for producing information of

  road traffic, equipment for producing road traffic information which is provided for implementing such a method and a system for producing road traffic information which uses a plurality of such equipment. It also relates to a road navigation system as well as road navigation equipment which is provided with said system.

  Various methods for producing road traffic information have already been proposed. In this regard, reference may be made to patent documents WO-A-98/36397, WO-A-99/24952 and WO-A-99/44183. According to the first of these documents, the production of road traffic information is carried out by combining, on the one hand, information relating to the movement of the vehicles, such as information on the location and / or speed of the vehicles brought up to a central and, on the other hand, global average speeds calculated from fixed receivers. According to the second, short messages indicating the actual position of each vehicle are transmitted, via a wireless telephone network, to a processing center where average speeds are determined on predetermined sections of road. Finally, according to the third, the positions of the vehicles come from a network positioning server or

of the mobiles themselves.

  This road traffic information can be viewed, in text or graphic form on a screen that includes the production equipment. They

  can be used in a road navigation system.

  Such road navigation systems are also known and we can

  refer as an example to patent document WO-A-96/07 110 and EP-A933 616.

  In these documents, the systems for collecting and producing road traffic information described consist essentially of a fixed server and of a plurality of devices on board vehicles for which the road traffic information is intended. More precisely, each on-board device essentially consists of a positioning unit determining the position of the vehicle (generally using a GPS (Global Positioning System) system), a dialogue unit with the user, a communication unit with the server (generally using a mobile telephone network such as the GSM network) and a data processing unit transmitted by the server. As for the server, it essentially comprises at least one database in which geographical maps are recorded, a unit for collecting road traffic information, a unit for processing geographical map data and road traffic information and a unit Communication

with each mobile device.

  A route calculation unit also constitutes such a road navigation system. According to the embodiments, this unit is located entirely or even partially either in the fixed server, or in each on-board device.

  The operation of such a road navigation system is as follows.

  The user present in the vehicle to be guided formulates a request indicating in particular the place where he wishes to go. Also included in this request is the position it occupies which is given by the positioning unit. Based on this

  query, geographic information from the database containing the maps and road traffic information valid for the user are determined and for example transmitted to the user. The route calculating unit also determines an optimum route between the current position and the place of destination which is then offered to the user.

  In the following description and in the claims, we will call

  movement information of a vehicle, information that relates to the location of that vehicle, its actual or instantaneous speed, and generally speaking, any information that can be used to describe in a way or a other its displacement. This information is raw information.

  Information relating to the state and characteristics of road traffic in a given geographical area will be called road traffic information. This information is in particular developed from the raw information that constitutes the movement information of a plurality of vehicles. For example, for a given road axis, it may be the overall average speed, the number of vehicles per hour, the presence or not of a traffic jam, etc.

  In the following description but also in the claims, we

  Road traffic information will refer to all information relating to road traffic in a given geographical area. It can therefore be the information on the movement of individual vehicles, road traffic information but also information relating to the conditions which may affect the

  road traffic such as weather conditions.

  All known methods for producing road traffic information consist in concentrating on one or more fixed and / nodal points information relating to each vehicle of a plurality of vehicles relating to the movement of this vehicle, then to deducing therefrom in a centralized computing unit, information of

  road traffic which is then re-broadcast to this plurality of vehicles.

  However, it turns out that all of the processing which goes from the collection of information on the movement of each vehicle 5 to the production of road traffic information and then to the dissemination of the latter to vehicles requires relatively large computing resources. , which results in significant processing times and therefore, for each vehicle, times to obtain this information also

relatively large.

  The aim of the present invention is to provide a new production system

  traffic information which allows each vehicle to obtain this traffic information in a shorter time than with the systems of the prior art. More specifically, the present invention proposes to provide an equipment for producing road traffic information which allows the establishment of a system for producing road traffic information which solves the problems mentioned above.

  To this end, a method of producing road traffic information according to the present invention is characterized in that it consists in determining said road traffic information locally at the level of a vehicle on the basis of information on movement of said road. vehicle and on the basis of road traffic information that it receives respectively from production equipment

  traffic information of other vehicles.

  It may consist in determining said road traffic information also

  on the basis of road traffic information which it receives from at least one fixed item of equipment.

  Advantageously, said road traffic information includes vehicle movement information. Likewise, said road traffic information includes locally produced road traffic information. More specifically, a method of producing road traffic information according to the present invention is characterized in that it comprises the steps of: determining the location of said vehicle in which it is installed, broadcasting via a network of the "ad-hoc" type "the traffic information of said vehicle relating to said location determined in the previous step, receiving traffic information from other vehicles, and determining on the basis of movement information of said vehicle and on the basis of traffic information of said other vehicles, said information from

road traffic.

  Advantageously, it uses a database in which are stored

  data relating to the description of the road network surrounding said vehicle.

  According to an advantageous mode of implementation, it consists in accompanying said road traffic information with a list of recipient equipment and, upon receipt of the road traffic information accompanied by a list of recipient equipment, it consists in retransmit said road traffic information to the equipment from which it has already received traffic information

  but which are absent from the said list of recipient equipment.

  It advantageously includes a step of comparing information from

  traffic received with traffic information generated locally and to keep and disseminate the most relevant.

  The present invention also relates to an equipment for producing road traffic information which is characterized in that it is intended to be installed in a vehicle and in that it is provided for implementing a method for producing information traffic as described above. More specifically, this equipment comprises: location means provided for determining the location of said vehicle in which it is installed and for delivering information on the movement of said vehicle, transmission / reception means provided for, on the one hand, broadcasting via a network 25 of the "ad-hoc" type, the traffic information of said vehicle relating to said location determined by said location means and, on the other hand, to receive the traffic information transmitted by the equipment of said other vehicles and / or said fixed equipment (s), and calculation means for determining on the basis of the movement information of said vehicle and on the basis of the traffic information of said

  other vehicles, said road traffic information.

  It advantageously further comprises a database in which are

  stored data relating to the description of the road network surrounding said road

  vehicle. The present invention also relates to road navigation equipment

  intended to be installed in a vehicle which is characterized in that it comprises equipment for producing road traffic information as just described and in that it determines road navigation information according to the base said 5 traffic information that said equipment for producing traffic information determined and data relating to the description of the road network

surrounding said vehicle.

  Advantageously, said data relating to the description of the road network

  surrounding said vehicle are stored in a database that includes said equipment.

  The present invention also relates to an information production system

  traffic equipment which is characterized in that it consists of a plurality of equipment for producing road traffic information respectively installed in vehicles, each of said equipment being in accordance with equipment for producing traffic information road as just described.

  This system for producing road traffic information comprises, according to a particular embodiment, at least one fixed item of equipment provided for receiving the road traffic information broadcast by equipment for producing road traffic information which it comprises, as well as said road traffic information which they transmit and to re-transmit them to a database of

centralized data.

  The present invention also relates to a road navigation system.

  The features of the invention mentioned above, as well as others,

  will appear more clearly on reading the following description of an exemplary embodiment, said description being made in relation to the accompanying drawings, among

  which: Fig. 1 shows vehicles equipped with equipment for producing road traffic information according to the present invention communicating via an "ad-hoc" network, FIG. 2 is a block diagram of equipment for producing road traffic information or road navigation according to the invention, and FIG. 3 is a diagram showing over time the transmissions and receptions of equipment for producing road traffic or navigation information

road according to the invention.

  According to the present invention, as already mentioned above, equipment for producing road traffic information is installed in a vehicle and is provided for broadcasting road traffic information to a set of equipment for producing traffic information other vehicles and to receive them from these vehicles or, possibly, from at least one fixed equipment provided for this purpose. There is shown in FIG. 1 a set of four vehicles 1 to 4 which can communicate with each other and therefore exchange traffic information via a mobile telecommunications network 5 which is of the so-called type

  "ad-hoc" network. We also see in this Fig. 1 fixed equipment 6.

  Generally, such an "ad-hoc" network is a network defined as a set of mobile units interconnected so as to form a temporary network.

  without pre-existing infrastructure and centralized administration.

  Such an "ad-hoc" network is, for example, a network standardized at the IEEE under the so-called 802.11-1997 standard in chapter 11 defining the specifications of its access layer and of its physical layer. More specifically, such a network according to the IEEE standard

  802.11 is intended to operate in an independent configuration mode in which the mobile units can communicate directly with each other so that no infrastructure needs to be installed. It can also operate according to a mode with an infrastructure configuration which is not the mode which concerns the present invention. In the first mode only, the network is an "adhoc" network.

  It will be noted that in the independent configuration mode, the MAC access layer of the network is provided with a means to allow a mobile unit to access the network and therefore to enter into communication with at least one other mobile unit without disrupt other communications and, in particular, avoid collisions. 25 For example, in an 802.11 network, a protocol called CSMA / CA (Carrier Sense

  Multiple Access with Collision Avoidance) is implemented.

  There is shown in FIG. 2 a piece of equipment for producing road traffic information 10 according to an embodiment of the present invention and which is provided with each of the vehicles 1 to 4 shown in FIG. 1. This equipment 10 comprises a transmission / reception unit 11 to be able to transmit and receive vehicle traffic information to or from other similar or identical equipment in accordance with a telecommunications protocol of the "ad-hoc" network. 5. It also includes a location unit 12 which determines the location of the vehicle and delivers information on the movement of said vehicle, for example its coordinates whether or not accompanied by the instantaneous speed or the average speed of the vehicle. These coordinates are for example expressed in latitude and longitude or in coordinates conforming to geodetic references known as WGS 84 (Word Geodetic System 1984) or to another equivalent system. It also includes a central computing unit 13 connected to the location unit 12 to receive the vehicle movement information there and to the transmission / reception unit 11 in order to be able to transmit or

  receive traffic information.

  It is recalled here that in the present description and in the claims,

  Road traffic information means any information relating to road traffic in a given geographical area. It can therefore be the movement information of individual vehicles, road traffic information but also information relating to the conditions which may affect road traffic

  such as weather conditions.

  According to the present invention, by means of the transmission / reception unit 11, the equipment 10 of a vehicle broadcasts from time to time to the equipment for producing road traffic information 10 from other vehicles capable of transmitting them. receive (in particular because they are within its reach) road traffic information such as for example the movement information relating to its current position or to several of its successive positions, information determined and delivered by the location unit 12 , and / or road traffic information which are determined and delivered by the calculation unit 13. Advantageously, the equipment for producing road traffic information 10 broadcasts such information at time intervals.

  regular according to a period T, for example of the order of 20 to 30 seconds.

  The message broadcast by an item of equipment 10 when the latter is for example carrying vehicle movement information can take the following form: [identifier of the transmitting equipment, type of addressing: broadcasting, type of message: location information Number of transmitted positions, (current position, corresponding speed), (previous position, corresponding speed), (still previous position, corresponding speed), ...] Always, by means of the transmission / reception unit 11, equipment 10 receives

  also the traffic information relating to the other vehicles within its reach, that is to say its vicinity. This traffic information may be only the movement information of the other vehicles within its reach, but it may also be traffic information originating from these same vehicles. By methods known per se, on the basis of the movement information of the vehicle in which the equipment is installed and on the basis of the traffic information received from the other vehicles, the calculation unit 13 will determine the relative traffic information to the geographic area where the vehicle in which the equipment is installed is located.

  By way of example and illustration, there is shown in FIG. 3, the broadcasting D of movement information of the vehicle 1 at regular time intervals of period T as well as the reception of the movement information F2, F3 and F4 respectively broadcast by the vehicles 2, 3, 4. It will be noted that the periods emission for the latter 15 are substantially equal to T. This ensures that between two D broadcasts, the equipment 10 of the vehicle 1 has received all the information broadcast by the equipment of the other vehicles. Although advantageous, this provision is not

  essential to the present invention as will be understood later.

  The calculation unit 13 then determines on the basis of the movement information 20 delivered by the location unit 12, on the one hand, and on the basis of the road traffic information transmitted by other vehicles and received by the transmission / reception unit 11, on the other hand, information relating to road traffic in a given area. This information is for example shown to the user at

  by means of a man / machine interface 14 that comprises said equipment 10.

  The equipment 10 may include a database 15 in which are

  stored data relating to the description of the road network surrounding the vehicle and more particularly data relating to the description of the road axes constituting this road network. Note that there is no relationship between the road network and the communication network. The calculation unit 13 can therefore assign to each road axis one or more parameters constituting the traffic information.

  road: for example, to one axis is assigned an overall average speed of so much, to another, another overall average speed, etc. The road traffic information is then shown to the user by means of the man / machine interface 14 in correspondence with a map representative of the road network with its road axes.

  They can be shown explicitly, for example textually, but also under

graph form.

  The calculation unit 13 can also propose, for example by means of

  the man / machine interface, to the user one or more preferential routes in this road network. The equipment 10 is then a road navigation equipment according to the present invention.

  In an exemplary embodiment of the present invention, the unit 13 for calculating the equipment 10 can perform the following operations: reporting the positions of the vehicles on the road axes whose coordinates 10 are provided by the database 15, - calculate the average speed of all vehicles in the near past on a given road axis, - compare this average speed with an average reference speed for this particular axis or for this particular type of road axis (this speed reference average indeed depends on the road axis considered according to whether it is an alley, a boulevard, a road, a motorway, etc.), - render on a screen (generally by means of the human interface / machine 14) the results of this comparison. For example, a color code could be associated with different speed ranges relative to the average reference speed: the road axes for which the speed is reduced compared to the reference speed (for example 50% lower than the speed of

  reference) are shown in red while they are green in other cases.

  According to an advantageous embodiment of the present invention, the equipment 10 is also provided for broadcasting to the equipment 10 vehicles for which it has received travel information, road traffic information relating to the

  results of the calculations made by the calculation unit 13. For example, to do this, the equipment 10 draws up a list of identifiers of the equipment 10 for which it has already received movement information. These identifiers are for example contained in the messages carrying location information (see the example above 30 where the message carries the identifier of the transmitting equipment).

  There is shown in FIG. 3 the transmission of this traffic information by the arrow marked Dc. It will be noted that this emission is not necessarily made with the same period as the diffusions D of information of displacement. In practice, it seems advantageous that this issue should be made at a period

  longer than the period T between two broadcasts.

  The message carrying this consolidated information could take the following form: [identifier of the sending equipment, type of addressing: broadcasting to equipment 10 of the list of identifiers, (there is transmission of the list of identifiers) number qualified information (location, average speed for this location, corresponding event code, reliability of information, etc.); (other locator, average speed for this other

  locator, corresponding event code, reliability of information); ...

  ] The locator is for example a place name, or the coordinates of a place, or a reference to objects gathered in a table - for example according to the Alert C standard. For the event code of a locator, it can s 'act with information on the presence of a traffic jam, a slowdown. This code can be in accordance with the Alert C standard. As for the reliability information, it can be calculated as a function of the number of vehicles taken into account for the establishment of the traffic information, the average speed and the event code, depending on the standard deviation of the vehicle speeds taken into account, etc. All this information (location, average speed for this location, code

  corresponding event, reliability of information, etc.) are in fact an example of what is called in the present description and in the claims, the information

of road traffic.

  It will be noted that when an item of equipment 10 receives road traffic information with a list of identifiers (present in the message carrying said information) which does not correspond to its own list, it may retransmit this information to the items of equipment 10 of its own list but which do not belong to the distribution list, in particular when this information differs significantly from

  traffic information that it can disseminate.

  This characteristic has the advantage that two pieces of equipment 10 which are not within the range of one another can nevertheless exchange road traffic information via other pieces of equipment 10. To explain this, reference is made to the example shown in Fig. 4. A first device 101 has in its mailing list the devices 102 and 103. The device 102, which can therefore receive information from the device 101, has in its mailing list the devices 101, 5 103, 104 and 105. It will be noted that the equipment 104 and 105 are not in the distribution list of the equipment 101. However, when the equipment 102 receives the traffic information from the equipment 101, it will retransmit them to the

equipment 104 and 105.

  According to an advantageous characteristic of the present invention, when the equipment 10 receives road traffic information, it compares them with the road traffic information which it has calculated from the traffic information which it has determined and it chooses the more relevant, for example based on indices of

  reliability that accompany them respectively.

  Note that the stationary equipment 6 shown in FIG. 1 could have the same structure as the traffic information production equipment which equips the

  vehicles 1 to 4, with the exception of the man / machine interface 14 which is not useful.

  This equipment can also be provided to receive the movement information of each vehicle as well as the traffic information emanating from these vehicles and retransmit them to a central database in which all this information is recorded. This last database could then be

  accessible by other navigation systems.

  It will be noted that a system for producing road traffic information or road navigation according to the invention could comprise several fixed pieces of equipment.

such as stationary equipment 6.

Claims (11)

  1) Method for producing road traffic information, characterized in that it consists in determining said road traffic information locally at the level of a vehicle on the basis of movement information of said vehicle and on the basis of information traffic it receives respectively from traffic information production equipment from other vehicles. 2) A method of producing road traffic information according to claim 1, characterized in that it consists in determining said road traffic information also on the basis of road traffic information which it receives from at least one fixed equipment.   3) Method for producing road traffic information according to claim 1 or 2, characterized in that said road traffic information comprises   vehicle movement information.   4) Method for producing road traffic information according to one of the   Claims 1 to 3, characterized in that said road traffic information 15 includes locally produced road traffic information.   ) Method for producing road traffic information according to one of the   previous claims, characterized in that it comprises the steps of   determine the location of said vehicle in which it is installed, disseminate via an "ad-hoc" type network the traffic information 20 of said vehicle relating to said location determined in the previous step, receive traffic information from others vehicles, and determining on the basis of the movement information of said vehicle and on the basis of the traffic information of said other vehicles, said information of road traffic.   6) Method for producing road traffic information according to one of the   previous claims, characterized in that it uses a database in which data relating to the description of the road network are stored surrounding said vehicle.   7) Method for producing road traffic information according to one of the preceding claims, characterized in that it consists in accompanying said traffic   road traffic information from a list of destination equipment, and in that, upon receipt of road traffic information accompanied by a list of destination equipment, it consists in re-transmitting said road traffic information to the equipment whose it has already received traffic information   but which are absent from the said list of recipient equipment.   8) Method for producing road traffic information according to claim 6   or 7, characterized in that it includes a step of comparing the traffic information received with traffic information generated locally and to keep and disseminate the most relevant.   9) Equipment for producing road traffic information, characterized in that   that it is intended to be installed in a vehicle, in that it is intended to implement a method for producing road traffic information according to one of claims 10 to 8.   ) Equipment for producing road traffic information according to claim 9, characterized in that it comprises: location means provided for determining the location of said vehicle in which it is installed and for delivering displacement information of said vehicle, transmission / reception means provided for, on the one hand, broadcasting via an "ad-hoc" type network the traffic information of said vehicle relating to said location determined by said location means and, on the other hand, to receive road traffic information transmitted by the equipment of said other vehicles and / or said stationary equipment (s), and calculation means for determining on the basis of movement information of said vehicle and on the basis of traffic information of said   other vehicles, said road traffic information.   11) Equipment for producing road traffic information according to one of claims 9 or 10, characterized in that it comprises a database in   which are stored data relating to the description of the road network surrounding said vehicle.   12) Road navigation equipment intended to be installed in a vehicle,   characterized in that it comprises equipment for producing road traffic information in accordance with one of claims 9 to 11 and in that it determines   road navigation information according to said road traffic information that said road traffic information production equipment has determined and data relating to the description of the road network surrounding said   vehicle. 13) Road navigation equipment according to claim 10, characterized in   what said data relating to the description of the surrounding road network said   vehicle are stored in a database that includes said equipment.   14) Road traffic information production system, characterized in that it consists of a plurality of road traffic information production equipment respectively installed in vehicles, each of said equipment being in accordance with equipment for producing traffic information according to one of the claims 9 to 11.   ) A system for producing road traffic information according to claim 10 14, characterized in that it comprises at least one fixed device provided for receiving the traffic information broadcast by equipment for producing traffic information that it thus includes the said road traffic information which they emit and to re-transmit them to a database of centralized data.   16) Road navigation system, characterized in that it consists of a   plurality of road navigation equipment respectively installed in vehicles conforming to one of claims 12 or 13 and / or   production of road traffic information in accordance with one of claims 9 to 11.