Communication system for platooning vehicles

Abstract

A communication system for a platooning vehicle according to an embodiment of the present invention is provided. In a communication system for a platooning vehicle that performs V2V (Vehicle-to-Vehicle) communication through control units mounted on the platooning vehicles, each of the control units includes a communication unit that transmits and receives a message containing control and sensor information of each of the platooning vehicles, a scheduling unit that stores the message transmission time between the platooning vehicles, and a determination unit that determines whether a message received by the communication unit corresponds to scheduling information stored in the scheduling unit. Each of the control units transmits a message according to an order determined based on the scheduling information, and the control units can determine the message transmission order of the platooning vehicles by sharing the scheduling information with each other.

Description

Technology Field

[0001] The present invention relates to a communication system for platooning vehicles that can improve the real-time nature of information by identifying the loss or error of a message transmitted by the platooning vehicles in real time. Background Technology

[0002] Platooning of large trucks is a type of autonomous transportation technology in which multiple cargo vehicles travel together in a convoy. It is expected to not only innovate the future logistics industry but also drastically reduce major traffic accidents. Platooning is known to offer excellent environmental benefits, such as improved fuel efficiency and reduced emissions, as it minimizes air resistance on the following trucks. Since vehicles in platoons drive cooperatively by sharing real-time vehicle control information—such as acceleration and deceleration—as well as data collected from various sensors via V2V (Vehicle-to-Vehicle) communication, the reliability of communication and the real-time nature of the information are critical.

[0003] However, existing communication methods cannot guarantee communication reliability because there is no mechanism to verify the success of message transmission. Furthermore, if messages are transmitted only at fixed intervals, if a message transmitted by a vehicle is lost or an error occurs, other vehicles will be unable to access that vehicle's information for at least one cycle, thus failing to guarantee real-time information. To improve communication reliability, a conventional method has been adopted where each vehicle adds information on all other vehicles it currently possesses to its own data and transmits it as a single packet. However, storing information on all other vehicles requires additional memory, and as the message size increases, the probability of errors during transmission may actually rise, leading to problems such as increased transmission time. The problem to be solved

[0004] The technical problem of the present invention is to provide a communication system for platooning vehicles that can improve the real-time nature of information by identifying the loss or error of messages transmitted by platooning vehicles in real time.

[0005] The technical problem of the present invention is to provide a communication system for platooning vehicles that allows all platooning vehicles to share information for platooning without requiring excessive memory for the vehicle.

[0006] The technical objective of the present invention is to provide a communication system for platooning vehicles that does not require separate logic to identify a vehicle in which an error has occurred in message transmission, and can prevent a delay in updating information of platooning vehicles after an error in message transmission has occurred. means of solving the problem

[0007] A communication system for a platooning vehicle according to an embodiment of the present invention is provided. In a communication system for a platooning vehicle that performs V2V (Vehicle-to-Vehicle) communication through control units mounted on the platooning vehicles, each of the control units includes a communication unit that transmits and receives a message containing control and sensor information of each of the platooning vehicles, a scheduling unit that stores the message transmission time between the platooning vehicles, and a determination unit that determines whether a message received by the communication unit corresponds to scheduling information stored in the scheduling unit. Each of the control units transmits a message according to an order determined based on the scheduling information, and the control units can determine the message transmission order of the platooning vehicles by sharing the scheduling information with each other.

[0008] In one example, it further includes a time measuring unit that measures the current time synchronized between the platooning vehicles based on the time synchronized with the GPS signal.

[0009] In one example, the communication unit matches the current time measured by the time measuring unit with the scheduling information and transmits messages in sequence, and the time measuring unit measures the time at which the message is received by the communication unit.

[0010] By way of example, it further includes a cluster vehicle set unit that stores information about the cluster vehicles and determines changes in the cluster vehicles.

[0011] For example, the platoon vehicle set unit transmits information about new platoon vehicles to the scheduling unit when a new vehicle joins the platoon driving or an existing vehicle leaves the platoon driving.

[0012] For example, the platoon vehicle assembly unit that detects that a change has occurred in the platoon vehicles is a component of the master control unit mounted on the leader vehicle among the platoon vehicles.

[0013] In one example, the scheduling unit of the master control unit sets the message transmission order of the new vehicle to be the first or last in a cycle when the new vehicle joins the platoon driving.

[0014] In one example, the scheduling unit determines new scheduling information, and determining the new scheduling information includes calculating the message transmission interval of the new platooning vehicles by considering the platooning message period and the number of the new platooning vehicles, and determining the message transmission order based on the synchronized time between the new platooning vehicles.

[0015] For example, even if the number of the platooning vehicles changes, the platooning message cycle of the platooning vehicles does not change.

[0016] For example, if the Nth vehicle that does not match the scheduling information transmits a message, the judgment unit determines that the message of the N-1th vehicle, which must transmit a message before the Nth vehicle, has been lost or an error has occurred.

[0017] In one example, if the vehicles in the platoon do not receive a message for a certain time interval in the sequence in which the N-1st vehicle transmits a message, the Nth vehicle, which is the vehicle in the next sequence after the N-1st vehicle, transmits a message at the time when the N-1st vehicle is supposed to transmit a message.

[0018] For example, after the Nth vehicle transmits a message, the N-1st vehicle transmits a message at the time when the Nth vehicle is supposed to transmit a message according to the schedule information, and the scheduling unit updates the scheduling information based on the fact that the message transmission order of the Nth vehicle and the N-1st vehicle has changed.

[0019] For example, if the specific vehicle that transmitted the message received from the communication unit does not match the message transmission order stored in the scheduling information, the judgment unit determines that the message of the vehicle corresponding to the order prior to the specific vehicle has been lost or an error has occurred.

[0020] For example, the message transmission interval of the platooning vehicles is the value obtained by dividing the platooning message period of the platooning vehicles by the number of the platooning vehicles.

[0021] For example, the transmission intervals of the messages transmitted by the platoon of vehicles are different from each other.

[0022] For example, if the vehicles in the platoon fail to receive a message for a certain time interval in the sequence in which the N-1th vehicle transmits a message, the leader vehicle among the vehicles in the platoon transmits a message at the time when the N-1th vehicle is supposed to transmit a message.

[0023] For example, if the vehicles in the platoon fail to receive a message for a certain time interval in the sequence in which the N-1st vehicle transmits a message, the vehicle physically closest to the N-1st vehicle transmits a message at the time when the N-1st vehicle is supposed to transmit a message.

[0024] By way of example, a roadside device is provided that stores information about the platooning vehicles and determines changes in the platooning vehicles, and when a new vehicle joins the platooning or an existing vehicle leaves the platooning, the roadside device transmits new scheduling information, including a new message transmission interval and a new message transmission order, to the new platooning vehicles based on information about the new platooning vehicles.

[0025] In one example, the communication unit transmits a message to the platoon of vehicles using a broadcast method. Effects of the invention

[0026] According to an embodiment of the present invention, each of the control units can determine in real time which vehicle's message has been lost when messages are not received in a predetermined order, without the need for control logic to separately locate the vehicle that transmitted the loss / error message. Therefore, the reliability of communication between platooning vehicles can be guaranteed without a mechanism to verify the success or failure of message transmission.

[0027] According to an embodiment of the present invention, by giving a specific vehicle that transmitted a loss / error message an opportunity to transmit a message again, the problem of all vehicles in a platoon being unable to share information about a specific vehicle at a specific period can be resolved. Brief explanation of the drawing

[0028] FIG. 1 is a block diagram showing a communication system of a platooning vehicle according to an embodiment of the present invention. FIG. 2 is a diagram showing a new vehicle according to an embodiment of the present invention joining a platoon. FIG. 3 is a diagram illustrating centralized scheduling according to an embodiment of the present invention. FIG. 4 is a diagram illustrating distributed scheduling according to an embodiment of the present invention. FIG. 5 is a flowchart illustrating centralized scheduling according to an embodiment of the present invention. FIG. 6 is a flowchart illustrating distributed scheduling according to an embodiment of the present invention. FIG. 7 is a diagram showing a variation of the message transmission interval between platooning vehicles according to an embodiment of the present invention. FIG. 8 is a diagram showing a modified example of centralized scheduling according to an embodiment of the present invention. FIG. 9 is a diagram showing a modified example of distributed scheduling according to an embodiment of the present invention. Specific details for implementing the invention

[0029] The advantages and features of the present invention and the methods for achieving them will become clear by referring to the embodiments described below in detail together with the accompanying drawings. However, the present invention is not limited to the embodiments disclosed below but can be implemented in various different forms. These embodiments are provided merely to ensure that the disclosure of the present invention is complete and to fully inform those skilled in the art of the scope of the invention, and the present invention is defined only by the scope of the claims. Throughout the entire specification, the same reference numerals refer to the same components.

[0030] Terms such as "...part," "...unit," and "...module" as described in the specification refer to a unit that processes at least one function or operation, and this may be implemented in hardware, software, or a combination of hardware and software.

[0031] In addition, the classification of the names of components in this specification as "first," "second," etc., is intended to distinguish them due to identical names, and is not necessarily limited to that order in the following description.

[0032] The detailed description is illustrative of the present invention. Furthermore, the foregoing describes preferred embodiments of the present invention, and the present invention may be used in various other combinations, modifications, and environments. That is, modifications or alterations are possible within the scope of the concept of the invention disclosed herein, the scope equivalent to the disclosed content, and / or the scope of the art or knowledge. The described embodiments describe the best state for implementing the technical concept of the present invention, and various modifications required for specific fields of application and uses of the present invention are possible. Accordingly, the above detailed description of the invention is not intended to limit the present invention to the disclosed embodiments. Furthermore, the appended claims should be interpreted as including other embodiments.

[0034] FIG. 1 is a block diagram showing a communication system of a platooning vehicle according to an embodiment of the present invention.

[0035] Referring to FIG. 1, a control unit (1) implementing a communication system for a platooning vehicle may include a communication unit (100), a platooning vehicle assembly unit (200), a time measurement unit (300), and a scheduling unit (400). The communication unit (100), the platooning vehicle assembly unit (200), the time measurement unit (300), and the scheduling unit (400) may be distinguished according to the functions of the control unit (1) for platooning vehicle mounted on the vehicle. In this case, platooning vehicle may mean driving cooperatively by sharing vehicle control information, such as acceleration and deceleration, and information collected from various sensors of the vehicle in real time through V2V (Vehicle-to-Vehicle) communication. The control unit (1) is a controller for communication between platooning vehicles composed of a plurality of vehicles, and can transmit and receive messages to share the status of the platooning vehicles in real time. Additionally, the control unit (1) may be provided to each of the platooning vehicles. One of the vehicles in the platoon may be defined as a leader vehicle that directs the platoon driving. A control unit (1) mounted on the leader vehicle may be defined as a master control unit.

[0036] The communication unit (100) can transmit and receive messages containing control and sensor information for each of the platooning vehicles. Since the communication unit (100) transmits messages in a broadcast manner, the communication unit (100) of all platooning vehicles can receive all messages transmitted by each of the platooning vehicles. The communication unit (100) can transmit messages at a set time and in a set order based on scheduling information. For example, scheduling information may include information such as the number of platooning vehicles, the driving order of the platooning vehicles, the message transmission interval between platooning vehicles, and the message transmission order of the platooning vehicles. Additionally, the communication unit (100) of the master control unit can receive messages requesting to join or leave from a new vehicle joining the platooning or from a vehicle leaving the platooning.

[0037] The platoon vehicle assembly unit (200) stores information about the platoon vehicles and can determine changes in the platoon vehicles. The platoon vehicle assembly unit (200) can be applied to the master control unit of the leader vehicle among the platoon vehicles. That is, the platoon vehicle assembly unit (200) of the master control unit can determine changes in the platoon vehicles. However, a control unit (1) other than the master control unit may also include the platoon vehicle assembly unit (200). The platoon vehicle assembly unit (200) can identify new vehicles joining the platoon or vehicles leaving the platoon. Specifically, new vehicles joining the platoon or vehicles leaving the platoon can send a message requesting to join or leave to the leader vehicle, and based on the message requesting to join or leave obtained through the communication unit (100), the platoon vehicle assembly unit (200) can update information such as the number of platoon vehicles and the driving order of the platoon vehicles. New scheduling information updated by the platoon driving vehicle assembly unit (200) can be transmitted to the scheduling unit (400).

[0038] The time measuring unit (300) can measure the current time synchronized among the platooning vehicles based on the time synchronized with the GPS signal. The time measuring unit (300) can synchronize time through message transmission between multiple platooning vehicles. Accordingly, the communication unit (100) can match the current time measured by the time measuring unit (300) with scheduling information and transmit messages in order, and the time measuring unit (300) can measure and store the time at which the message was received by the communication unit (100).

[0039] The scheduling unit (400) can determine new scheduling information. For example, when a new vehicle joins the platooning or an existing vehicle leaves the platooning, the scheduling unit (200) can determine a new message transmission interval and a new message transmission order based on the number of platooning vehicles determined by the platooning vehicle set unit (200) and the driving order of the platooning vehicles. Specifically, the scheduling unit (400) can calculate the message transmission interval of the new platooning vehicles by considering the platooning message cycle and the number of new platooning vehicles, and can determine the message transmission order based on the synchronized time between the new platooning vehicles. At this time, even if the number of platooning vehicles changes, the platooning message cycle of the platooning vehicles may not change. The message transmission interval of the platooning vehicles may be a value obtained by dividing the platooning message cycle of the platooning vehicles by the number of platooning vehicles. Therefore, if the number of vehicles in a platoon increases, the message transmission interval of the vehicles in the platoon can be reduced, and if the number of vehicles in the platoon decreases, the message transmission interval of the vehicles in the platoon can be increased.

[0040] The judgment unit (500) can determine whether there is an error in the message received from the communication unit (100) and can determine whether the received message is a message transmitted by a vehicle that matches the scheduling information. If the specific vehicle that transmitted the message received from the communication unit (100) does not match the message transmission order stored in the scheduling information, the judgment unit (500) can determine that the message of the vehicle corresponding to the order prior to the specific vehicle will be lost. Additionally, the judgment unit (500) can determine whether there is an error in the message itself based on a code that can determine a message error and a logic that determines whether the received message is a message transmitted by a vehicle that matches the scheduling information and whether the data is valid. The judgment unit (500) can control the communication unit (100) to transmit a message based on the scheduling information stored by the scheduling unit (400) or the scheduling information newly determined by the scheduling unit (400).

[0041] The judgment unit (500) of the platooning vehicles can receive messages from the platooning vehicles in real time. If a message from a vehicle in a predetermined order is not received, the vehicle in the next order can transmit a message first based on the scheduling information. If a vehicle that is not in the original order transmits a message, the judgment unit (500) can determine that the message of the vehicle that should have transmitted a message in the order prior to the vehicle that is not in the original order has been lost or that an error has occurred in the message. That is, without a separate judgment logic, the judgment unit (500) can determine in real time whether a message transmitted by a vehicle has been lost or an error has occurred in the message based on the scheduling information shared by the platooning vehicles. In addition, the control unit (1) that transmitted the loss / error message can determine in real time whether the transmitted message has been lost or an error has occurred in the message.

[0042] After a specific vehicle transmits a message, the determination unit (500) of the vehicle that transmitted the loss / error message can control the communication unit (100) to transmit the message again. At this time, the determination unit (500) of the vehicle that transmitted the loss / error message can control the communication unit (100) to transmit the message in the order in which the specific vehicle was originally supposed to transmit the message based on scheduling information.

[0043] For example, if the Nth vehicle, which does not match the scheduling information, transmits a message, the judgment unit (500) may determine that the message of the N-1st vehicle, which is supposed to transmit a message before the Nth vehicle, has been lost or an error has occurred. Additionally, if the platooning vehicles do not receive the message for a certain time interval during the sequence in which the N-1st vehicle transmits a message, the Nth vehicle, which is the vehicle in the next sequence after the N-1st vehicle, may transmit the message at the time when the N-1st vehicle is supposed to transmit the message. After the Nth vehicle transmits the message, the N-1st vehicle may transmit the message at the time when the Nth vehicle is supposed to transmit the message according to the schedule information. If the N-1st vehicle does not transmit the message even at the time when the Nth vehicle is supposed to transmit the message according to the original schedule information, the judgment unit (500) may determine that a problem has occurred with the N-1st vehicle itself. The logic for determining that a problem has occurred with the vehicle itself may be applied when the message transmitted by the N-1st vehicle is not received by other platooning vehicles at least twice. At this time, the scheduling unit (400) can update the scheduling information based on the fact that the message transmission order of the Nth vehicle and the N-1th vehicle has changed. The updated scheduling information can be transmitted by the communication unit (100) to other platooning vehicles under the control of the judgment unit (500) of the master control unit.

[0044] According to an embodiment of the present invention, each of the control units (1) deployed in the platoon of vehicles can transmit a message according to an order determined based on scheduling information. The control units (1) can identify the message transmission order of the platoon of vehicles by sharing the scheduling information with one another. Therefore, if a specific vehicle transmits a message outside of the set order, all platoon of vehicles can identify that the message of the vehicle preceding that specific vehicle has been lost or that an error has occurred in the message. Additionally, if a specific vehicle transmits a message outside of the set order, the control unit (1) of the vehicle that transmitted the lost / erroneous message can identify that there is a problem with the message it transmitted. That is, without a separate control logic to find the vehicle that transmitted the lost / erroneous message, each of the control units (1) can identify in real time which vehicle's message has been lost when a message according to the set order is not received. Therefore, the reliability of communication between the platoon of vehicles can be guaranteed without a mechanism to verify the success or failure of message transmission.

[0046] FIG. 2 is a diagram showing a new vehicle joining a platooning drive according to an embodiment of the present invention, and FIG. 3 is a diagram for explaining centralized scheduling according to an embodiment of the present invention.

[0047] Referring to FIGS. 1 to 3, there may be platooning vehicles (V1, V2, V3 to Vn) and a new vehicle (Vj) that intends to join the platooning. At this time, among the platooning vehicles (V1, V2, V3 to Vn), the leader vehicle commanding the platooning may be the first vehicle (V1). That is, the control unit (1) of the first vehicle (V1) may be a master control unit. In this embodiment, the platooning message period may be set to T.

[0048] The new vehicle (Vj) can send a message requesting to join the first vehicle (V1). That is, the communication unit (100) of the new vehicle (Vj) can send a message requesting to join. The first vehicle (V1) can send a message approving platooning. The platooning vehicle assembly unit (200) of the first vehicle (V1) recognizes that the number of platooning vehicles has increased by one and can determine the driving order of the new vehicle (Vj).

[0049] The cluster vehicle assembly unit (200) of the first vehicle (V1) can transmit information regarding the number of clustered vehicles and the driving order of the clustered vehicles to the scheduling unit (400) of the first vehicle (V1).

[0050] The scheduling unit (400) of the first vehicle (V1) can set the message transmission order of the new vehicle (Vi) to be the first or last in a cycle when a new vehicle (Vj) joins the platoon driving. The scheduling unit (400) can determine new scheduling information including a new message transmission interval and a new message transmission order based on the number of vehicles in the platoon driving and the driving order of the vehicles in the platoon driving. For example, the new message transmission interval (g') may be smaller than the existing message transmission interval (g). However, the platoon driving message cycle (T) may not be changed. For example, the existing message transmission order is V1→V2→V3→…→Vn, and after a new vehicle (Vj) additionally joins the platoon driving, 'centralized scheduling' by the master control unit is performed, and the message transmission order may be changed to V1→V2→V3→…→Vn→Vj according to the newly scheduled information.

[0051] The communication unit (100) of the first vehicle (V1) can transmit new scheduling information to new platooning vehicles (V2, V3 to Vn and Vj). The new vehicle (Vj) can join the communication of the platooning vehicles from the next cycle based on the time it joined the platooning. That is, in the existing cycle (P), only the previous platooning vehicles (V1, V2, V3 to Vn) communicate, and in the new cycle (P'), the new platooning vehicles (V1, V2, V3 to Vn and Vj) communicate.

[0053] FIG. 4 is a diagram illustrating distributed scheduling according to an embodiment of the present invention.

[0054] Referring to FIGS. 1 and FIGS. 4, the message transmission order of the platooning vehicles (V1, V2, V3 to Vn) is V1→V2→V3→…→Vn. The distributed scheduling described in this embodiment may refer to a scheduling method for correcting message loss / error in the event that a message from one vehicle is lost or an error occurs in a message from one vehicle.

[0055] In communication between existing platooning vehicles (V1, V2, V3 to Vn), a message transmitted by the first vehicle (V1) is lost or an error occurs in the message. If the second vehicle (V2), which is the next vehicle in the sequence, fails to receive the message of the first vehicle (V1) at a set time, or if there is an error in the message of the first vehicle (V1) received by the second vehicle (V2) at a set time, the second vehicle (V2) may transmit a message after a certain time interval (δ) has elapsed. As a result of the second vehicle (V2) transmitting a message after a certain time interval (δ) has elapsed, rather than at the preset message transmission interval, the other platooning vehicles (V1, V3 to V4) can identify in real time that the message of the first vehicle (V1) has been lost or an error has occurred in the message.

[0056] Based on the scheduling information, at the time when the second vehicle (V2) needs to transmit a message, the first vehicle (V1), which is the vehicle in the previous order, can transmit the message again. That is, even if other platooning vehicles (V2, V3 to Vn) do not request the first vehicle (V1) to transmit the message again, the first vehicle (V1) transmits the message at the time when the second vehicle (V2) needs to transmit the message. The scheduling unit (400) of the control units (1) installed in each vehicle recognizes that the message transmission order of the first vehicle (V1) and the second vehicle (V2) has changed, and can determine new scheduling information according to the changed order. The new scheduling information determined by the scheduling unit (400) of each vehicle can be shared with each other. Therefore, in the next cycle, the message transmission order of the platooning vehicles (V1, V2, V3 to Vn) can be changed to V2→V1→V3→…→Vn.

[0057] If messages are transmitted only in a fixed order, when a loss or error occurs in a message transmitted by a specific vehicle, other vehicles in the platoon cannot know the information of that specific vehicle for at least one period, and thus the real-time nature of the information cannot be guaranteed. According to an embodiment of the present invention, by giving the specific vehicle that transmitted the loss / error message an opportunity to transmit the message again, the problem of all vehicles in the platoon being unable to share the information of that specific vehicle within a specific period can be resolved.

[0059] FIG. 5 is a flowchart illustrating centralized scheduling according to an embodiment of the present invention. In this embodiment, centralized scheduling of a master control unit mounted on a leader vehicle is described. For brevity of the description, redundant content is omitted.

[0060] Referring to FIGS. 1 and FIGS. 5, the leader vehicle can notify surrounding vehicles that it is providing a platooning service. Specifically, the communication unit (100) of the master control unit mounted on the leader vehicle can output a notification that it is providing a platooning service (S100).

[0061] The platoon vehicle set unit (200) stores information about the platoon vehicles and can determine changes in the platoon vehicles. The platoon vehicle set unit (200) can determine changes in the platoon vehicles. Specifically, when a new vehicle joins the platoon or an existing vehicle leaves the platoon, the platoon vehicle set unit (200) can determine the number of vehicles continuing the platoon and the driving order of the vehicles (S110).

[0062] New scheduling information can be set based on the number of vehicles continuing to drive in a platoon. The scheduling unit (400) can determine a new message transmission interval and a new message transmission order based on the number of vehicles continuing to drive in a platoon. Specifically, the scheduling unit (400) can calculate the message transmission interval of new vehicles in a platoon by considering the platoon driving message cycle and the number of new vehicles in a platoon, and can determine the message transmission order based on the synchronized time between the new vehicles in a platoon. At this time, even if the number of vehicles in a platoon changes, the platoon driving message cycle of the vehicles in a platoon may not change (S120).

[0063] The judgment unit (500) can transmit the newly determined scheduling information by the scheduling unit (400) to other platoon driving vehicles. That is, the leader vehicle can transmit new scheduling information to other platoon driving vehicles. Accordingly, the platoon driving vehicles transmit messages based on the new scheduling information (S130).

[0065] FIG. 6 is a flowchart illustrating distributed scheduling according to an embodiment of the present invention. In this embodiment, distributed scheduling of a control unit installed in each of the platooning vehicles is described. For brevity of the description, redundant content is omitted.

[0066] Referring to FIGS. 1 and FIGS. 6, the judgment unit (500) can control the communication unit (100) to transmit a message based on scheduling information set by the scheduling unit (400) (S200).

[0067] The time measuring unit (300) can determine whether a message has been received at a set time, and the judgment unit (500) can determine whether a message from a vehicle matching the scheduling information has been received (S210).

[0068] When the platooning vehicles receive a message at a set time, the judgment unit (500) can determine whether an error has occurred in the received message using an error detection algorithm. If no error has occurred in the received message, the platooning vehicles can transmit and receive messages based on the originally determined scheduling information (S220).

[0069] If the vehicles in the platoon do not receive a message for a set time interval, the judgment unit (500) may determine that the message has been lost. For example, if the vehicles in the platoon do not receive a message for a set time interval during the sequence in which the N-1st vehicle transmits a message, the vehicles in the platoon may determine that the message transmitted by the N-1st vehicle has been lost. Additionally, if the vehicles in the platoon receive the message from the N-1st vehicle but an error occurs in the received message, the vehicles in the platoon may determine that an error occurred in the message transmitted by the N-1st vehicle. If the vehicles in the platoon do not receive a message for a set time interval during the sequence in which the N-1st vehicle transmits a message, the Nth vehicle, which is the vehicle next in the sequence after the N-1st vehicle, may transmit a message at the time when the N-1st vehicle is supposed to transmit a message. This is based on the premise that, according to existing scheduling information, the Nth vehicle is determined to transmit a message after the N-1st vehicle has transmitted a message (S230).

[0070] After the Nth vehicle transmits a message, the N-1th vehicle that transmitted the loss / error message can transmit a message at the time when the Nth vehicle is supposed to transmit a message according to the schedule information. That is, the time when the N-1th vehicle and the Nth vehicle transmit messages can be swapped. Through this, if a message from a specific vehicle is lost or an error occurs in the message, the problem of a specific vehicle's message not being shared during communication between vehicles for one period can be resolved (S240).

[0071] The scheduling unit (400) can determine new scheduling information based on the fact that the times for transmitting messages have changed. The scheduling unit (400) can share the changed message transmission order with other platoon vehicles. Accordingly, the platoon vehicles can transmit and receive messages according to the changed message transmission order (i.e., new scheduling information) (S250).

[0073] FIG. 7 is a diagram showing a variation of the message transmission interval between platooning vehicles according to an embodiment of the present invention.

[0074] Referring to FIG. 7, the transmission intervals of messages transmitted by the platooning vehicles (V1, V2, V3 to Vn) may differ from one another. For example, the interval between the time when the first vehicle (V1) transmits a message and the time when the second vehicle (V2) transmits a message may be a first transmission interval (g1), and the interval between the time when the second vehicle (V2) transmits a message and the time when the third vehicle (V3) transmits a message may be a second transmission interval (g2), and the first transmission interval (g1) and the second transmission interval (g2) may differ from each other. However, the platooning message period from when the first vehicle (V1) transmits a message until the first vehicle (V1) transmits a message again may be set to T. The transmission interval of messages may be adaptively set according to the physical distance between the platooning vehicles (V1, V2, V3 to Vn).

[0076] FIG. 8 is a diagram showing a modified example of centralized scheduling according to an embodiment of the present invention.

[0077] Referring to FIG. 8, when the number of vehicles in a platoon changes, the scheduling information for newly set message transmission times for the new vehicles in the platoon can be transmitted from the vehicle with the most remaining CPU resources, the vehicle with the fewest communication interference factors due to distance from each vehicle and obstacles, or the edge computer or cloud server of the roadside unit (50) closest to the platoon. In other words, the entity transmitting the new scheduling information to other vehicles may change depending on various driving situations, rather than only the leader vehicle of the platoon sharing the new scheduling information with other vehicles.

[0078] For example, a roadside device (50) that stores information about vehicles in a platoon and determines changes in the vehicles in the platoon may be provided. When a new vehicle joins the platoon or an existing vehicle leaves the platoon, the roadside device (50) may transmit new scheduling information, including a new message transmission interval and a new message transmission order, to the new vehicles in the platoon based on information about the new vehicles in the platoon. The roadside device (50) may be configured to be positioned at regular intervals near the road in which the vehicle is traveling.

[0080] FIG. 9 is a diagram showing a modified example of distributed scheduling according to an embodiment of the present invention.

[0081] Referring to Fig. 9, when a loss or error occurs in a message, the vehicle that is physically closest to the vehicle that transmitted the lost or erroneous message and thus has the lowest probability of communication error due to radio interference compared to other vehicles, the leader vehicle that manages the overall platooning, or the vehicle pre-designated to handle the error event can notify that a loss or error has occurred in the message by sending a message at a different time than its own message transmission time in the scheduling information.

[0082] For example, if the platooning vehicles (V1, V2, V3 to Vn) fail to receive a message during the sequence in which the first vehicle (V1) transmits a message, the third vehicle (V3), which is a vehicle pre-designated to handle the error event among the platooning vehicles (V1, V2, V3 to Vn), may transmit a message first. That is, if the first vehicle (V1) fails to transmit a message during the sequence in which the first vehicle (V1) transmits a message, the third vehicle may transmit a message at the time when the first vehicle (V1) is supposed to transmit a message. At this time, the first vehicle (V1) may immediately transmit a message in the next sequence. That is, messages may be transmitted in the order of the third vehicle (V3), the first vehicle (V1), and the second vehicle (V2).

[0083] As another example, if the platoon of vehicles (V1, V2, V3 to Vn) do not receive the message for a certain time interval in the sequence in which the first vehicle (V1) transmits the message, the vehicle physically closest to the first vehicle (V1) (in this embodiment, the third vehicle (V3)) can transmit the message at the time when the first vehicle is supposed to transmit the message.

[0084] Unlike the example described above, if the third vehicle (V3) transmits a message at the time when the first vehicle (V1) is supposed to transmit a message, the second vehicle (V2) can transmit a message based on the original scheduling information. At this time, the first vehicle (V1) can transmit a message at the time when the third vehicle (V3) is supposed to transmit a message. Consequently, messages can be transmitted in the order of the third vehicle (V3), the second vehicle (V2), and the first vehicle (V1).

[0085] Although embodiments of the present invention have been described above with reference to the attached drawings, those skilled in the art will understand that the present invention may be implemented in other specific forms without changing its technical concept or essential features. Therefore, the embodiments described above should be understood as illustrative in all respects and not restrictive.

Claims

Claim 1 A communication system for platooning vehicles that performs V2V (Vehicle-to-Vehicle) communication through control units mounted on the platooning vehicles, wherein each of the control units comprises: a communication unit that transmits and receives a message containing control and sensor information of each of the platooning vehicles; a scheduling unit that stores the message transmission time between the platooning vehicles; and a determination unit that determines whether a message received by the communication unit corresponds to scheduling information stored in the scheduling unit; wherein each of the control units transmits a message according to an order determined based on the scheduling information, and the control units share the scheduling information with each other to determine the message transmission order of the platooning vehicles, and if the platooning vehicles fail to receive a message for a certain time interval in the order in which the N-1th vehicle transmits a message, another vehicle transmits a message in the order in which the N-1th vehicle transmits a message. Claim 2 A communication system for platooning vehicles according to claim 1, further comprising a time measuring unit that measures the current time synchronized between the platooning vehicles based on the time synchronized with the GPS signal. Claim 3 A communication system for a platooning vehicle according to claim 2, wherein the communication unit matches the current time measured by the time measuring unit with the scheduling information and transmits messages in sequence, and the time measuring unit measures the time at which the message is received by the communication unit. Claim 4 A communication system for a platoon of vehicles according to claim 1, further comprising a platoon vehicle set unit that stores information about the platoon of vehicles and determines changes in the platoon of vehicles. Claim 5 In claim 4, the platoon vehicle assembly unit transmits information about new platoon vehicles to the scheduling unit when a new vehicle joins the platoon driving or an existing vehicle leaves the platoon driving, in a communication system for platoon vehicles. Claim 6 In claim 5, the platoon vehicle assembly unit that detects that a change has occurred in the platoon vehicles is a component of a master control unit mounted on a leader vehicle among the platoon vehicles, and is a communication system of platoon vehicles. Claim 7 In claim 6, the scheduling unit of the master control unit sets the message transmission order of the new vehicle to be the first or last in a cycle when the new vehicle joins the platooning. A communication system for platooning vehicles. Claim 8 A communication system for a platooning vehicle according to claim 5, wherein the scheduling unit determines new scheduling information, and determining the new scheduling information includes calculating the message transmission interval of the new platooning vehicles by considering the platooning message period and the number of the new platooning vehicles, and determining the message transmission order based on the synchronized time between the new platooning vehicles. Claim 9 A communication system for platooning vehicles according to claim 8, wherein the platooning message cycle of the platooning vehicles is not changed even if the number of the platooning vehicles is changed. Claim 10 A communication system for platooning vehicles according to claim 1, wherein the judgment unit determines that when the Nth vehicle that does not match the scheduling information transmits a message, the message of the N-1th vehicle that must transmit a message before the Nth vehicle is lost or an error has occurred. Claim 11 A communication system for platooning vehicles according to claim 10, wherein if the platooning vehicles fail to receive a message for a certain time interval in the order in which the N-1st vehicle transmits a message, the Nth vehicle, which is the vehicle in the next order of the N-1st vehicle, transmits a message at the time when the N-1st vehicle is supposed to transmit a message. Claim 12 A communication system for platooning vehicles according to claim 11, wherein after the Nth vehicle transmits a message, the N-1st vehicle transmits a message at the time when the Nth vehicle is supposed to transmit a message according to the scheduling information, and the scheduling unit updates the scheduling information based on the fact that the message transmission order of the Nth vehicle and the N-1st vehicle has changed. Claim 13 A communication system for platooning vehicles according to claim 1, wherein the judgment unit determines that the message of a vehicle corresponding to the order prior to the specific vehicle has been lost or an error has occurred when the specific vehicle that transmitted the message received from the communication unit does not match the message transmission order stored in the scheduling information. Claim 14 A communication system for platooning vehicles according to claim 1, wherein the message transmission interval of the platooning vehicles is a value obtained by dividing the platooning message period of the platooning vehicles by the number of the platooning vehicles. Claim 15 A communication system for platooning vehicles according to claim 1, wherein the transmission intervals of messages transmitted by the platooning vehicles are different from each other. Claim 16 A communication system for platooning vehicles according to claim 1, wherein if the platooning vehicles fail to receive a message for a certain time interval in the order in which the N-1st vehicle transmits a message, the leader vehicle among the platooning vehicles transmits a message at the time when the N-1st vehicle is supposed to transmit a message. Claim 17 A communication system for platooning vehicles according to claim 1, wherein if the platooning vehicles fail to receive a message for a certain time interval in the order in which the N-1st vehicle transmits a message, the vehicle physically closest to the N-1st vehicle transmits a message at the time when the N-1st vehicle is supposed to transmit a message. Claim 18 A communication system for platooning vehicles according to claim 1, wherein a roadside device is provided for storing information about the platooning vehicles and determining changes in the platooning vehicles, and the roadside device transmits new scheduling information, including a new message transmission interval and a new message transmission order, to the new platooning vehicles based on information about the new platooning vehicles when a new vehicle joins the platooning or an existing vehicle leaves the platooning. Claim 19 A communication system for platooning vehicles according to claim 1, wherein the communication unit transmits a message to the platooning vehicles using a broadcast method.

Images