WO2005029438A1

WO2005029438A1 - A traffic information exchange method

Info

Publication number: WO2005029438A1
Application number: PCT/KR2004/002380
Authority: WO
Inventors: Jae Moon Choi
Original assignee: Atn Co. Ltd.
Priority date: 2003-09-22
Filing date: 2004-09-16
Publication date: 2005-03-31
Also published as: KR100515952B1; KR20030096111A

Abstract

The invention relates to a method of traffic information exchange using inter vehicle communication. Most of the methods for collecting and distributing road traffic information use external wireless infrastructure networks such as a cellular network, WLAN, TRS network and pager network so it causes huge initial network deployment cost, maintenance cost as well as network data communication delay. The invention is about the method of determining the forward traffic situation by exchanging travel history with opposite lane's vehicle terminal. The vehicle sends its travel history data and its opposite direction vehicle's travel history data received from the opposite direction vehicle's terminal previously, to current communicable vehicles. The traffic information of the front is processed using received data from opposite direction vehicles and data from the vehicles that have passed already. A driving history includes time-location data and/or speed data which represent the moving trace of a vehicle. This invention presents a method for generating and exchanging traffic information without help of a roadside wireless control tower, wireless relay device or center server for traffic information management.

Description

A TRAFFIC INFORMATION EXCHANGE METHOD

[Field of the Invention] The invention concerns direct exchange of traffic information among vehicles, and in particular, it is collecting and distributing technplogy of traffic information which is part of the Intelligent Transport System.

[Description of the Prior Art] The field concerning collecting and distributing of traffic information are becoming the core of Intelligent Transport System. Traffic information includes traffic jams in certain sections of a road, road conditions after an accident, amount of traffic flow, speed, and so on. Up to now, for collecting traffic information, magnetic roof sensors were set on the road surface, traffic information collecting cameras above ground and location data receiving module in vehicles to send fundamental data through wired or wireless communication network to the center computer which is used to process the traffic information, and this is summarized and shown on VMS(Variable Messaging System) or sent to the receiving terminal inside the vehicle through wireless communication network. This form of traffic information collection or distributing process certainly requires fixed set of exclusive facility or equipment, and specially requires infrastructure wireless communication network like cellular wireless phone network, TRS (trunked radio system) network and wireless paging system to provide information into vehicle. This requires not only the complexity of the system but also the maintenance cost, and causes problems on providing traffic information at an appropriate time.

[Summary of the Invention] The invention relates to a method of traffic information exchange using direct wireless communication among vehicles and by exchanging information not through various main facilities on side of the road and public wireless communication network but through direct communication between wireless communication terminals installed in vehicles. Main purpose of this invention is that collecting and distributing required traffic information can be proceeded directly through vehicle-to-vehicle ad-hoc communication. Using this invention, fixed facilities on roadside for collecting and distributing traffic information will almost be useless and wire/wireless infrastructure communication network will no longer be needed. Therefore, free acquisition and use of information will be possible without the infrastructure network fee and recognizing the traffic conditions ahead will be possible in a flash. Also, collecting and distributing traffic information will be possible on country roads without wire/wireless infrastructure network. The method of exchanging traffic information directly, according to the invention to achieve the goal above consist of, the storing process which is revising existing data and storing new data received from the terminal installed in vehicle, which is acquired after transmitting and receiving information between vehicle's terminal from opposite direction, the process of transmission which is transmitting stored data above to vehicles approaching from the opposite side, and the process of updating, which is updating existing data using the received one from the vehicle's terminal and saving for the newly approaching terminals of opposite direction, which are the distinct features for the method of exchanging information through wireless data communication among terminals set in vehicles. On one side, the method of exchanging information through wireless data communication between terminals installed in vehicles without a control tower or an external network consists of the process of travel location information storing process, which is updating and saving data of vehicle's terminal location according to time periodically, the process of processing data, which stores travel location data received from the vehicle's terminal of opposite direction, and the process of transmission which transmits travel location information of the process above and location data of the opposite directional inter vehicle terminal process above at a certain time interval or at a time when it contacts a vehicle's terminal of the opposite direction, which are the distinct features. Also, The method of exchanging information through wireless data communication between terminals installed in vehicles without a control tower or an external network consists of these processes; the process of information field adding process which adds message relay information field that distinguishes whether a certain information transmitting message unit is incoming or outgoing. the process of message transmission which transmits information transmitting message after indicating whether it's incoming or outgoing message of the message rely field above, and the process of information transmitting method by detour route which includes process of retransmitting the incoming information message after examining it and changing it to outgoing message.

The method of exchanging information through wireless data communication between terminals installed in vehicles without a control tower or an external network consists of these processes; the first step, in which wireless information is received from other terminals and when the data referred above includes passing information of the ongoing vehicle, it adjusts the collection of the opposite direction data it keeps and maintains, and when the data includes retro-directional data of the approaching terminal, it adjusts its collection of traffic information of ahead or sends it to an output device already set. the second step which when the location data is received it updates the forward direction travel history it keeps and maintains, and the third step which is sending its collection of forward directional travel history wireless, or sending collection of the opposite directional data it keeps and maintains, referring to the periodic or non-periodic signal, To achieve the goal stated above, certain terminal must keep and maintain at least these sets below. First, its collection of forward direction travel history that includes terminal location's alteration information according to time interval, second, the collection of opposite direction data that includes travel history received from the vehicle of opposite lane, and third, its collection of forward traffic information which is composed of the collection of forward direction data received from the opposite direction terminal. The forward direction above refers to the direction of the vehicle that is being considered, and the opposite direction refers to the direction opposite direction of the vehicle that is considering. Also if you vehicle is traveling upward, it refers to the upward lane and traveling down, opposite lane. The collection of your forward direction travel history data is for offering traffic information to the vehicle behind via opposite direction's terminal, and collection of opposite direction data is maintained to offer the information of the opposite direction's terminal about the front to the vehicle that will encounter later on. And collection of the traffic information data of the front which has the latest traffic information is used for itself. The terminal installed in vehicles uses inter-terminal wireless communication to send the collection of forward direction travel history and opposite direction data stated above to the opponent, and uses the collection of forward traffic information data stated above for itself which is processed by receiving the opponent's collection of forward data. As stated, the new method of exchanging traffic information by inter-vehicle direct communication is an epoch-making discovery due to the fact that latest traffic information can be collected and distributed by only the inter vehicle terminal without a infrastructure facility or a network. Also, not only is infrastructure facility using fee free but also it's effective in offering the traffic information for the public use because when a terminal is fixed on the side of the road and connected to wire network, the data from the vehicle can rather be transmitted to the network. So far, concrete examples of foremost usage of this invention were stated but as for the technical field of this invention, one with common sense can figure out that it can be operated with various changes. Therefore, actual examples can not deviate from the technology in this invention.

[Description of the Drawings] Fig. la or fig.lc shows the process of exchanging traffic information using the invention, which is inter- vehicle direct communication. Fig.2 shows the general idea of bi-directional information exchange of inter vehicle terminal using the traffic information exchanging method. Fig.3 shows an example of the detour communication route of the incommunicable terminals. Fig.4 shows the procedures of the traffic information exchange through inter- vehicle direct communication. Fig.5 shows the structure of the message exchanged when vehicles communicate.

Definition of the major symbols in the drawings: 100 : centerline of a road 101,102,103 : vehicle's on-board terminal of p-direction 111 : vehicle's on-board terminal of q-direction 201,202,203 : vehicle's on-board terminal of p-direction 211,212,213 : vehicle's on-board terminal of q-direction [1], [2] ,[3], [4] : wireless communication link identification

[Description of the Preferred Embodiments] Using the inter-vehicle direct communication, the foremost substantial examples of traffic information exchange method are shown. Fig. la, Fig. lb and Fig.lc show the process of sending forward traffic information to the terminal installed in vehicle using the inter- vehicle direct communication. As illustrated, fig. la is for explaining the process of how the traffic information is sent to p-direction vehicle A-2(102) and vehicle A-3(103)'s terminals, and it is in vehicle B-l(lll)'s point of view, which is moving opposite direction of the two above. Fig. la shows the traveling moment at tO and fig. lb shows traveling moment at tl, and figlc shows traveling moment at t2.(t0 < tl < t2, the time epoch tO is before tl and the time epoch tl is before t2) Vehicles A-2(102), A-2(102) and A-3(103) of Fig.la or fig.lc shows the communication terminal installed in vehicle in p-direction and vehicle B-l(l l l) shows q-direction of the terminal installed in vehicle. First, when the message of vehicle A-(101)'s travel history is sent from vehicle A- 1(101) to vehicle B-(l l l), as shown on the figure lb, vehicle B-l(l l l) processes or saves it and sends[2] it to the terminal of following vehicle A-2(102). At this point, for the terminals of the opposite direction vehicles to be encountered later on, message including vehicle A-2(102)'s travel history is received form vehicle A-2(102) and it is stored or maintained. The information received[l] from vehicle A-l(lOl) of fig.la and information received[3] from vehicle A-2 is kept and maintained in vehicle B-l(l 11) for the following vehicle A-3(103)'s terminals, and is sent[4] to vehicle A-3(103) of fig.lc at t2. Through these procedures, the information transmitted by the terminals in front is sent to succeeding terminals, helped by the terminals of opposite direction. When the procedure above is applied to both directions, succeeding vehicle's terminal creates its travel history and sends it to the opposite terminal so it can be transmitted to the vehicles behind and relays messages received form the terminals of opposite direction to the rear of opposite direction's terminals. Also, messages created by the front of forward direction terminal is relayed by the opposite direction terminal, which is received to determine the front traffic information. Fig.2a, fig.2a and fig.2c are the general drawings of bi-directional information exchange based on the information exchanging terminal's progress situation. As shown, fig.2a, which explains basic method of information exchange, shows traveling moment at tO, fig.2b shows traveling moment at tl, and fig.2c shows traveling moment at t2.(t0 < tl < t2) Vehicle A-l(201), vehicle A-2(202), vehicle A-3(203) and vehicle A-4(204) on the diagram shows p-direction terminals in vehicles and vehicle B- 1(211), vehicle B- 1(212) and vehicle B-l(213) shows q-direction terminals. First, when vehicle A-l(201) and vehicle B-l(211)'s terminals approach closer and wireless communication become possible, vehicle A- 1(201) and vehicle B-l(211) exchanges their forward direction travel history and the collection of opposite direction data that they have kept and maintained. To explain at vehicle A-l(201)'s point of view, when vehicle A- 1(201) receives vehicle B-l(211)'s forward direction travel history, vehicle A- 1(201) updates or transmits its collection of traffic information data to an external data output device. Because, vehicle B-l(211)'s collection of opposite direction data includes vehicle A-l(201)'s forward traffic situation. Fig.2b shows fig.2a's traffic situation from tO to tl which the vehicles have traveled a bit. Wireless communication is possible for the vehicle A- 1(201) and vehicle B-2(212) of fig.2b and also vehicle A-2(202) and vehicle B-l(211), and vehicle A- 3(203) and vehicle B-l(211) are at possible state of communication. Vehicle A-l(201) and vehicle B-2(212) each exchange their collection of forward direction travel history, and use collection of opposite direction travel history received from the opponent to update their opposite direction data. And using the collection of opposite direction data received from the opponent, they update traffic information about the front. At present time and location, Vehicle B-l(211) transmits collection of its forward direction data(own travel history data) recently updated and collection of opposite direction data updated at tO to vehicle A-2(202) and vehicle A-3(203). Also, vehicle A-2(202) and vehicle A-3(203) each transmit forward direction travel history and the collection of its opposite direction data which they have kept and maintained. As a result of the communication above, vehicle A-2(202) and vehicle A-3(203) can determine the traffic information up to the spot of vehicle A- 1(201) at present standpoint. Data can be transmitted through the broadcasting form or form of personal communication link. In fig.2c which shows traffic situation of t2 which comes after fig.2a's tO and tl, the vehicle is at a state where it has moved a bit more, and new terminals of vehicle A- 4(204) and vehicle B-3(213) has approached. Present possible communication link at t2 are vehicle A- 1(201) and vehicle B-3(213), vehicle A-2(202) and vehicle B-2(212), vehicle A-3(203) and vehicle B-2(212), and vehicle A-4(204) and vehicle B-l(211). The methods of information exchange of each communication link are same for fig.2a and fig.2b. Vehicle B-3(213) of fig.2c can determine the forward traffic information of vehicles B-l(211) and B-2(212), which have passed already, by receiving vehicle A- l(201)'s collection of opposite data. And vehicle A-l(201)'s forward traffic information can be determined by referring to the opposite direction information sent by the vehicle B-3(213). Using the same method, vehicle A-4(204) can determine passed vehicle A- 1(201), vehicle A-2(202), and vehicle A-3(203)'s traffic information through the collection of opposite direction data sent by vehicle B-l(211). Fig.3 shows an example of using detour route of incommunicable terminals. As shown above, fig.3 explains communicating through detour route when an obstacle is intervened in between terminals and communication becomes impossible. By using not only the direct communication of fig.2 for information transmission but also the expansion of communication link using the middle terminal, information transmission is fortified. For every message received, classifying field determines whether it is an initial message from the message generating end or a retransmitted message from another terminal, and for the case of retransmitted terminal, an indication is added to show that it is retransmitted. So if vehicle A-2(302) and vehicle A-3(303)'s communication is impossible due to vehicle A-l(301), detour communication is possible via vehicle A-3(303). When the Vehicle A-3(303) receives the message from vehicle B-2(312) and if it is an initial message, it retransmits the message to the field stated above after adding an indication of retransmission. Reversely, vehicle A-3(303) retransmits the initial message received from vehicle A-2(202) helping vehicle B-2(312) to receive it. With this communication between vehicle B-2(312) and vehicle A-2(302) is possible. The initial message stated above refers to the case in which the message generating end and transmitting end are identical, and retransmitted message refers to case in which the generating end and transmitting end are different. Fig.4 illustrates a stark example of a message exchange using inter-vehicle wireless communication. The wireless data reception module(401) restores signal from other terminals and invokes an data reception event when proper information is received. The transmitter timer(402) which tells message receiving time periodically or non- periodically, creates a timer event. The GPS receiver, or the location-data generator module(403), which receives/calculates the present location of the terminal, generates a location data event when the location data is updated. The communication control processor confirms type of the event when an event takes a place during action standby mode (404), and does proper actions. When the generated event is the data reception event (405) and the processor is in the initial message data reception stage (408), the retransmission message pool is updated and activated (411). Also when the received data includes forward direction travel history(409), it is used to update the set of opposite direction data, and when the received data includes opposite direction data(410), it is used to adjust (413) its traffic information of the front of itself. If a generated event during action standby(404) is categorized as timer event(406), and when it is in activation after examining the retransmission pool (414), the contents of retransmission message pool is transmitted(415) to the wireless link after a certain delay(or random). Again after a certain delay(or random), it transmits(416) its forward travel history and transmits(417) collection opposite direction data. For the certain time indicated in fig.4, the procedures of transmitting retransmission message pool after a delay(415), deactivation(416) and transmitting opposite direction data set(417) doesn't have to be in sequence, and transmitting retransmission message pool after a delay(415) step can be even omitted. Also, the time delay mentioned above can be adjusted to fit any situation. If a generated event during action standby mode(404) is a location data event (407), its forward travel history is adjusted(418). When the event are all carried out it returns to the standby mode(404). Fig.5 offers an example of the structure of exchanged messages between vehicles. This message structure can hold various units of information including the address of the destination, origination and relay point, the handling method of message, the type of the message, and the length. It can also include detailed information such as the received time, longitude, latitude and altitude as well as the velocity of the vehicle terminal.

Claims

1. A traffic information exchange method using wireless data communication between terminals installed in vehicles without a support of any control tower or any external network, comprising the steps of: a) the storing which is revising existing data and storing new data, using information acquired from the results of wireless communication with opposite direction vehicle's terminal; b) the transmission which is transmitting the data above to vehicles approaching from the opposite side, c) the updating, which is updating existing data using the received one from opposite direction vehicle's terminal and saving for the newly approaching terminals of opposite direction

2. A traffic information exchange method for exchanging terminal's travel history data through wireless data communication between terminals installed in vehicles comprising the processes of: a) forward direction travel location data storing, which is updating and saving a data set of his own terminal's travel locations according to time; b) opposite direction travel data cooking and storing, which cooks and stores a set of travel location data received from the vehicle's terminal of opposite direction; c) transmission which transmits two travel location data sets above(a, b) at a certain time interval or at a time when it contacts vehicle's terminal of the opposite side.

3. A traffic information exchange method of route detouring for connecting unreachable terminal directly using relaying for exchanging traffic information through wireless data communication among terminals installed in vehicles, comprising the steps of: a) information field adding which adds message relay information field that distinguishes whether a certain information transmitting message unit is from an originator or from an intermediate relay terminal, b) transmission which transmits a message after indicating whether it's originating or relayed message of the message rely field above, c) reception and retransmission which receives a message from other transmitter and checks whether the destination of the received message is itself or not. If the destination is not its own, the step retransmits the received data with marked as the relay to the relay information field.

4. A traffic information exchange method for exchanging information through wireless data communication between terminals installed in vehicles considering terminal's moving direction comprising: a) the first step, in which data is received from other terminals and when the data includes travel history information of the upcoming vehicle at opposite direction, it adjusts the set of the opposite direction data it keeps and maintains, and when the data includes the travel history of going ahead vehicle of ongoing direction, it adjusts the set of traffic information of ahead. b) the second step which when a new location data of itself is made, it updates the forward direction travel history it keeps and maintains, c) the third step which transmits its collection of forward directional travel history, and/or transmits the collection of the opposite directional data it keeps and maintains to other terminal, referring to the periodic or non-periodic internal signal.