Method for adjusting PSM transmission period for v2x communication and device for same

Abstract

Proposed is a method for adjusting the transmission period of a personal safety message (PSM) for V2X communication, the method being performed by a vulnerable road user (VRU) terminal and comprising the steps of: receiving signal information, including the time remaining until a signal change of a signalling apparatus, from a road side unit (RSU) or a V2X server; performing scheduling for adjusting the transmission period of the PSM according to the received signal information; and transmitting the PSM according to the transmission period adjusted according to the scheduling.

Description

Method for controlling PSM transmission cycle for V2X communication and device therefor

[0001] The present invention relates to a device for traffic safety or traffic accident prevention using soft V2X, a method or system therefor, and more specifically, to a method for controlling a PSM (Personal Safety Message) transmission cycle of a VRU (Vulnerable Road User) and a device therefor.

[0002] Push-button pedestrian signals, now widely installed and widespread at crosswalks, trigger a signal change when a pedestrian presses a button on the signal if they intend to walk. This can vary depending on factors such as vehicle traffic volume, pedestrian traffic volume, and time of day.

[0003] Depending on the situation, the pedestrian signal may operate differently, such as only being activated when the button is pressed, or the pedestrian signal may be activated more quickly when the button is pressed. This can reduce unnecessary vehicle waiting in areas with low pedestrian traffic volume and protect pedestrian safety by clearly indicating the pedestrian signal in areas operated by flashing signals.

[0004] Similarly, recent crosswalks have installed red or green light remaining time indicators. When the pedestrian signal is red, the remaining red light time is displayed on the traffic light. When the pedestrian signal is green, the remaining green light time is displayed on the traffic light. This indicates the remaining time pedestrians have to wait or the time to cross, providing convenience to pedestrians and reducing jaywalking. After the remaining red light time, the pedestrian signal changes to a pedestrian signal, and pedestrians can cross the road until the remaining time of the pedestrian signal.

[0005] Figure 1 relates to a smart traffic management system using conventional soft V2X (vehicle to everything).

[0006] Soft V2X is a system and app that can predict collisions between vehicles and pedestrians by transmitting and receiving information (location, speed, direction) as messages between surrounding user terminals and servers, and prevent accidents in advance by notifying users of this in advance through user terminals.

[0007] The SoftV2X app transmits location, speed, and direction information to the server according to the SAE 2735 message format. For vehicles, it transmits a basic safety message (BSM), while for pedestrians, bicycles, and scooters, it transmits a personal safety message (PSM). Key elements in each message are as follows:

[0008] ElementDescriptionid4 octet random device identifiersecMarkTimestamplatLatitudelongLongitudeelevElevationaccuracyPositional Accuracyspeedspeedheadingcurrent heading of the sending deviceaccelSeta set of acceleration values ​​in 3 orthogonal directions

[0009] Smart RSUs, such as smart CCTVs, can detect objects from acquired images, calculate the object's position, direction, and speed, and include them in BSM or PSM to transmit to the SoftV2X server.

[0010]

[0011] The present invention proposes a method for managing power consumption by controlling the PSM transmission cycle of a Vulnerable Road User (VRU), and also proposes a method for increasing the safety of a VRU by shortening the PSM transmission cycle when the VRU crosses a road.

[0012] The present invention proposes a method for controlling the transmission cycle of PSM.

[0013] In addition, the present invention proposes a method for managing power consumption of a VRU or a VRU terminal by controlling the transmission cycle of PSM, or for improving pedestrian safety of a VRU.

[0014] The problems to be solved by the present invention are not limited to the problems to be solved above, and other problems not mentioned can be clearly understood by a person having ordinary skill in the technical field to which the present invention belongs from the description below.

[0015] A method for controlling a transmission cycle of a personal safety message (PSM) for V2X communication is proposed, the method being performed by a Vulnerable Road User (VRU) terminal, and may include the steps of: receiving signal information including a remaining time until a signal change of a signal from an RSU (Road Side Unit) or a V2X server; performing scheduling to control a transmission cycle of the PSM according to the received signal information; and transmitting the PSM according to the controlled transmission cycle according to the scheduling.

[0016] A method for controlling a transmission cycle of a personal safety message (PSM) for V2X communication is proposed, the method being performed by a Vulnerable Road User (VRU) terminal, and may include: a step of periodically updating current location information of the VRU terminal; a step of performing scheduling to control a transmission cycle of the PSM based on the updated current location; and a step of transmitting the PSM according to the controlled transmission cycle.

[0017] The above problem solving methods are only some of the embodiments of the present invention, and various embodiments reflecting the technical features of the present invention can be derived and understood by a person having ordinary knowledge in the relevant technical field based on the detailed description of the present invention described below.

[0018] The present invention has the following effects.

[0019] The present invention can control the transmission cycle of PSM.

[0020] In addition, the present invention can manage power consumption of a VRU or a VRU terminal by controlling the transmission cycle of PSM, or can improve pedestrian safety of a VRU.

[0021] In addition, the present invention can optimize power consumption of a VRU or a VRU terminal by controlling the transmission cycle of PSM.

[0022] The effects according to the present invention are not limited to the effects mentioned above, and other effects not mentioned will be clearly understood by those skilled in the art to which the present invention pertains from the detailed description of the invention below.

[0023] The accompanying drawings, which are included as part of the detailed description to aid in understanding the present invention, provide embodiments of the present invention and, together with the detailed description, explain the technical idea of ​​the present invention.

[0024] Figure 1 relates to a smart traffic management system using conventional soft V2X (vehicle to everything).

[0025] FIG. 2 illustrates a V2X-based smart traffic management system according to the present invention.

[0026] FIG. 3 illustrates a flowchart of a method for controlling a V2X-based PSM transmission period according to the present invention.

[0027] FIG. 4 illustrates a flowchart of a method for controlling a V2X-based PSM transmission period according to the present invention.

[0028] FIG. 5 illustrates a flowchart of a method for controlling a V2X-based PSM transmission period according to the present invention.

[0029] FIG. 6 illustrates a flowchart of a method for controlling a V2X-based PSM transmission period according to the present invention.

[0030] Figure 7 illustrates the setting of an area in an environment for controlling a V2X-based PSM transmission cycle according to the present invention.

[0031] Figure 8 illustrates a flowchart of a method for controlling a V2X-based PSM transmission period according to the present invention.

[0032] FIG. 9 illustrates a flowchart of a method for controlling a V2X-based PSM transmission period according to the present invention.

[0033] Figure 10 shows a comparison of the V2X-based PSM transmission cycle according to the present invention and the prior art.

[0034] Fig. 11 illustrates a block diagram of a device for controlling the PSM transmission cycle of the present invention.

[0035] Hereinafter, embodiments disclosed in this specification will be described in detail with reference to the attached drawings. Regardless of the drawing numbers, identical or similar components will be given the same reference numbers, and redundant descriptions thereof will be omitted. The suffixes "module" and "part" used for components in the following description are assigned or used interchangeably only for the convenience of writing the specification, and do not in themselves have distinct meanings or roles. In addition, when describing the embodiments disclosed in this specification, if it is determined that a specific description of a related known technology may obscure the gist of the embodiments disclosed in this specification, a detailed description thereof will be omitted. In addition, the attached drawings are only intended to facilitate easy understanding of the embodiments disclosed in this specification, and the technical ideas disclosed in this specification are not limited by the attached drawings, and should be understood to include all modifications, equivalents, and substitutes included in the spirit and technical scope of the present invention.

[0036] Terms that include ordinal numbers, such as first, second, etc., may be used to describe various components, but the components are not limited by these terms. These terms are used solely to distinguish one component from another.

[0037] When a component is referred to as being "connected" or "connected" to another component, it should be understood that it may be directly connected or connected to that other component, but that there may be other components intervening. Conversely, when a component is referred to as being "directly connected" or "connected" to another component, it should be understood that there are no other components intervening.

[0038] Singular expressions include plural expressions unless the context clearly indicates otherwise.

[0039] In this application, terms such as “include” or “have” are intended to specify the presence of a feature, number, step, operation, component, part or combination thereof described in the specification, but should be understood not to exclude in advance the possibility of the presence or addition of one or more other features, numbers, steps, operations, components, parts or combinations thereof.

[0040]

[0041] The SAE standards body defines the format and content of messages used in V2X in J2735 (V2X Communications Message Set Dictionary). Below, among the standardized messages, are described messages related to VRU transmission and reception.

[0042] Standard message

[0043] - BSM (Basic Safety Message)

[0044] BSM is used to transmit safety information related to the vehicle's status when the V2X device is a vehicle. Typically, messages are transmitted 10 times per second and can include information such as vehicle position, speed, direction, and vehicle events. This BSM can be received by other nearby vehicles, VRUs, and RSUs (Roadside Units) via V2X communication.

[0045]

[0046] BasicSafetyMessage ::= SEQUENCE {

[0047] -- Part I, Sent at all times with each message

[0048] coreData BSMcoreData,

[0049] -- Part II Content

[0050] partII SEQUENCE (SIZE(1..8)) OF

[0051] PartIIcontent {{ BSMpartIIExtension}} OPTIONAL,

[0052] regional SEQUENCE (SIZE(1..4)) OF

[0053] RegionalExtension {{REGION.Reg-BasicSafetyMessage}} OPTIONAL,

[0054] ...

[0055] }

[0056]

[0057] -- BSM Part I

[0058] BSMcoreData ::= SEQUENCE {

[0059] msgCnt MsgCount,

[0060] id TemporaryID,

[0061] secMark DSecond,

[0062] lat Latitude,

[0063] long Longitude,

[0064] elev Elevation,

[0065] accuracy PositionalAccuracy,

[0066] transmission TransmissionState,

[0067] speed Speed,

[0068] heading Heading,

[0069] angle SteeringWheelAngle,

[0070] accelSet AccelerationSet4Way,

[0071] brakes BrakeSystemStatus,

[0072] size VehicleSize

[0073] }

[0074]

[0075] -- BSM Part II content support

[0076] PARTII-EXT-ID-AND-TYPE ::= CLASS {

[0077] &id PartII-Id UNIQUE,

[0078] &Type

[0079] } WITH SYNTAX {&Type IDENTIFIED BY &id}

[0080]

[0081] PartIIcontent { PARTII-EXT-ID-AND-TYPE: Set} ::= SEQUENCE {

[0082] partII-Id PARTII-EXT-ID-AND-TYPE.&id( {Set} ),

[0083] partII-Value PARTII-EXT-ID-AND-TYPE.&Type( {Set}{@partII-Id} )

[0084] }

[0085]

[0086] PartII-Id ::= INTEGER (0..63)

[0087] vehicleSafetyExt PartII-Id::= 0 -- VehicleSafetyExtensions

[0088] specialVehicleExt PartII-Id::= 1 -- SpecialVehicleExtensions

[0089] supplementalVehicleExt PartII-Id::= 2 -- SupplementalVehicleExtensions

[0090] -- NOTE: new registered Part II content IDs will be denoted here

[0091]

[0092] -- In a given message there may be multiple extensions present

[0093] -- but at most one instance of each extension type.

[0094] BSMpartIIExtension PARTII-EXT-ID-AND-TYPE ::= {

[0095] { VehicleSafetyExtensions IDENTIFIED BY vehicleSafetyExt} |

[0096] { SpecialVehicleExtensions IDENTIFIED BY specialVehicleExt} |

[0097] { SupplementalVehicleExtensions IDENTIFIED BY supplementalVehicleExt},

[0098] ...

[0099] }

[0100]

[0101]

[0102] - PSM (Personal Safety Message)

[0103] PSM messages are V2X messages that allow VRUs to transmit their safety data to their surroundings. These messages primarily include the physical location, speed, and direction of various VRUs. The format of a PSM message is as follows, and the inclusion of optional values ​​is a non-standard matter and varies depending on the V2X system or service. The following shows the ASN.1 format of a PSM message.

[0104] PersonalSafetyMessage ::= SEQUENCE {

[0105] basicType PersonalDeviceUserType,

[0106] secMark DSecond,

[0107] msgCnt MsgCount,

[0108] id TemporaryID,

[0109] position Position3D, -- Lat, Long, Elevation

[0110] accuracy PositionalAccuracy,

[0111] speed Velocity,

[0112] heading Heading,

[0113] accelSet AccelerationSet4Way OPTIONAL,

[0114] pathHistory PathHistory OPTIONAL,

[0115] pathPrediction PathPrediction OPTIONAL,

[0116] propulsion PropelledInformation OPTIONAL,

[0117] useState PersonalDeviceUsageState OPTIONAL,

[0118] cross Request PersonalCrossingRequest OPTIONAL,

[0119] crossState PersonalCrossingInProgress OPTIONAL,

[0120] clusterSize NumberOfParticipantsInCluster OPTIONAL,

[0121] clusterRadius PersonalClusterRadius OPTIONAL,

[0122] eventResponderType PublicSafetyEventResponderWorkerType OPTIONAL,

[0123] activityType PublicSafetyAndRoadWorkerActivity OPTIONAL,

[0124] activitySubType PublicSafetyDirectingTrafficSubType OPTIONAL,

[0125] assistType PersonalAssistive OPTIONAL,

[0126] sizing UserSizeAndBehaviour OPTIONAL,

[0127] attachment Attachment OPTIONAL,

[0128] attachmentRadius AttachmentRadius OPTIONAL,

[0129] animalType AnimalType OPTIONAL,

[0130]

[0131] regional SEQUENCE (SIZE(1..4)) OF

[0132] RegionalExtension {{REGION.Reg-PersonalSafetyMessage}} OPTIONAL,

[0133] ...

[0134] }

[0135]

[0136] - VRU의 PSM 전송 주기

[0137] SAE standard J2945 / 9 (Vulnerable Road Safety Message minimum performance requirements) describes the minimum requirements for PSM messages transmitted by VRUs. The standard describes how to set the PSM transmission cycle to a random time (1 / Ti) or a fixed cycle, but does not define the transmission cycle as a precise number. It defines Transmission Timing Mode 1 and Transmission Timing Mode 2 as follows.

[0138] Transmission Timing Mode 1 describes a method to determine the transmission period Ti based on the moving speed of the VRU. This has the advantage of allowing an appropriate period to be set according to the moving speed of a VRU such as a bicycle, which has a relatively fast moving speed. If the VRU is moving faster than 15 m / s, it is set to Ti = vruHighSpdPSMTiConst [in / s], and if the VRU is moving slower than this, it is set to Ti = Ceilling[(-vruPSMTiCoeff*Vp+0.5)*100] / 100 [in / s]. This mode is a suitable method for the VRU to inform the vehicle of its location when there is a possibility of collision with an approaching vehicle around the VRU device. This is a method in which the transmission period of the PSM also changes as the moving speed changes. Transmission Timing Mode 2 is a method in which the PSM transmission period is fixed to a value between vruPSMTxRateMin and vruPSMTxRateMax. This is a transmission period value between 1 s and 100 ms according to the specification.

[0139]

[0140] Figure 2 illustrates a V2X-based smart traffic management system (1) according to the present invention.

[0141] The system (1) may be composed of a VRU (201), a vehicle (202), a network (203), a V2X server (204), a signal server (205), an RSU (206), a signal device (207), and a button-type pedestrian signal device (208).

[0142] VRU (201) is a subject that transmits PSM and is an object that can move on a sidewalk or roadside rather than a road, and can generally be a pedestrian, bicycle, roadside worker, pet, etc. In order to connect to the V2X service, VRU (201) carries a device such as a smartphone, and the VRU device can be connected to a vehicle (202) and RSU (206) through a communication method such as PC5 or DSRC. In addition, it can be connected to the Internet (203) through a base station through Uu communication such as LTE / 5G. In the case of VRU, PSM can be transmitted including its own information and location data. In this specification, VRU (201) is described as a concept that includes not only a person but also a mobile device such as a smartphone, i.e., a terminal carried by VRU.

[0143] The vehicle (202) is a vehicle defined in V2X, and can also be connected to an object such as a VRU (201) or an RSU (206) through direct communication such as PC5 or DSRC. Similarly, the vehicle (202) can be connected to an Internet network (203) through mobile communication such as LTE / 5G. The vehicle (202) periodically transmits BSM, and generally informs the surroundings of its moving location, speed, and direction information through BSM messages 10 times per second.

[0144] The V2X server (204) uses the V2X communication method for V2N2X (Vehicle-to-Network-to-Everything). The main purpose of the V2X server (204) is to receive messages from vehicles or VRUs that provide V2X services using Uu and broadcast them to a specific area.

[0145] The signal server (205) monitors and controls the signal system, and is primarily a server managed and controlled by the government or the National Police Agency. Each signal (207) is connected to the signal server (205), and performs control to change the signal of the corresponding signal when the signal changes and when a pedestrian presses a button-type pedestrian signal (208).

[0146] The RSU (206) is a type of roadside infrastructure. The RSU (206) communicates with VRUs (201) or vehicles (202) moving along the roadside via PC5 or DSRC. It primarily provides V2I (Vehicle-to-Infrastructure) or I2VRU communications. Furthermore, the RSU (206) provides Internet-connected communications, enabling communication with servers or other entities located on the network.

[0147] The signal (207) displays a pedestrian signal at a crosswalk. The signal (207) may display the remaining red light time or green light time, or may include a device that displays the remaining time. The remaining time can generally be monitored or confirmed by the signal server (205). For example, when a client queries the signal server (205) for the signal status of a specific signal, the signal server (205) may respond with information such as the current signal status of the signal and the remaining time until the signal changes (i.e., the remaining time).

[0148] The push-button pedestrian signal (208) is a button connected to the previously described signal (207), and is primarily pressed to change the signal when a pedestrian wishes to cross the road. When this button is pressed, the button sends a request to the signal server (205) for a signal change, thereby switching the signal (207) to a green light.

[0149] The primary purpose of the present invention is to recognize a VRU's plan or action to cross a lane or crosswalk and to adjust the PSM transmission cycle of the corresponding VRU. Below, a method for recognizing a VRU crossing a lane or crosswalk and providing signal information to the VRU to adjust the PSM transmission cycle is described.

[0150]

[0151] FIG. 3 illustrates a flowchart of a method for controlling a V2X-based PSM transmission period according to the present invention.

[0152] FIG. 3 shows a process in which a VRU (201) adjusts a PSM transmission cycle in conjunction with a button operation when a button-type pedestrian signal (208) is used in a V2X-based smart traffic management system (1).

[0153] As with Fig. 2, there is no limitation on the V2X communication method, and both V2N methods such as Uu and direct communication methods such as PC5 and DSRC are considered.

[0154] Additionally, while the process illustrated in FIG. 3 is in progress, the VRU (201) transmits PSM according to the set transmission cycle.

[0155] A push-button pedestrian signal (208), a signal (207) and an RSU (206) can constitute road infrastructure.

[0156] Additionally, it is assumed that the VRU (201) and the V2X server (204) have established a V2X session (S300).

[0157] It is assumed that the signal (207) is indicating a red light (T1). The VRU (201) is positioned in front of the crosswalk (T2). Until the VRU (201) is positioned in front of the crosswalk, the transmission cycle of the PSM can be Transmission Timing Mode 1 or Mode 2 as described above, and the transmission cycle of the PSM can be short or long. The present invention operates regardless of the PSM transmission cycle of the VRU or whether the power saving mode is operated until the arrival at the crosswalk.

[0158] The VRU (201) presses the button of the push-button pedestrian signal (208) (S301). The button is merely an example, and the push-button pedestrian signal (208) performs the function of transmitting a signal change request to the signal server (205). Accordingly, a method for triggering the transmission of a signal change request in a different way than the button may be used. For example, when the VRU (201) approaches the push-button pedestrian signal (208), the VRU (201) may be recognized through a proximity sensor or the like, and the push-button pedestrian signal (208) may transmit a signal change request to the signal server (205) accordingly.

[0159] The push-button pedestrian signal (208) can transmit a VRU presence notification or a signal change request to the signal device (207). In response, the signal device (207) can transmit a signal change request to the signal server (205) (S303).

[0160] The signal server (205) that receives the signal change request is responsible for the status and control of the signal, and thus can instruct the signal information of the corresponding signal device (207), i.e., to change to the next signal, and can know the remaining time information corresponding to the remaining time information until the signal change. Accordingly, the signal server (205) can determine the timing of the signal change (i.e., when the signal change should be performed, or the remaining time until the signal change).

[0161] The signal server (205) can update the remaining time of the current signal (i.e., red light) (S304) and transmit a signal change response including the remaining time information to the signal device (207) (S305). Here, the signal change response can include a signal change instruction and the remaining time (i.e., information on when the signal should be changed).

[0162] The signal (207) can update the remaining time information (S306) and transmit a trigger message including a VRU presence notification to the RSU (206) (S307). The RSU (206) can transmit the VRU presence notification to the V2X server (204) (S308). Here, the VRU presence notification can include the ID of the RSU, thereby transmitting which crosswalk or (signal) RSU the VRU presence notification was transmitted from.

[0163] The V2X server (204) can transmit a request for remaining time information to the signal server (205) (S309) and receive a response for remaining time information as a response (S310).

[0164] There are two possible methods for transmitting signal information from the V2X server (204) to the VRU (201).

[0165] As a first proposal, this is a method in which the RSU (206) has V2X communication capabilities.

[0166] The signal server (206) can transmit signal information to the RSU (206) (S311-1). The RSU (206) can transmit the received signal information to the VRU (201) (S311-2). The signal information can include remaining time information of the current signal.

[0167] As a second proposal, in the case where the RSU (206) does not have V2X communication capabilities, the VRU (201) is connected to the V2X server (204) via a mobile communication network such as LTE / 5G, and the signal server (205) and the V2X server (204) are connected in a manner such as a cloud-to-cloud connection. As mentioned above, through S309 to S310, the V2X server (204) can obtain remaining time information from the signal server (205). Accordingly, the V2X server (204) can transmit the signal information to the RSU (201) (S311). The signal information can include remaining time information of the current signal.

[0168] The format of the message for transmitting signal information can use SPAT (Signal Phase and Timing Message) and MAP (MapData Message) defined in the SAE standard, and can be transmitted through a separate non-standard message.

[0169] SPAT is defined as follows:

[0170]

[0171] Additionally, MAP is defined as follows:

[0172]

[0173] Intersections included in the MAP include a list of IntersectionGeometry (i.e., IntersectionGeometryList), which includes reference Position (latitude, longitude), lane width, speed limit, etc. It is configured to include the following information.

[0174]

[0175] Additionally, RoadSegments within the MAP include a list of RoadSegments, which similarly include road location information. In other words, the data included varies depending on whether the location is an intersection or a regular road.

[0176]

[0177] The present invention does not limit the format of the transmission message of signal information.

[0178] The signal information may include at least one of the following information: Preferably, the signal information may necessarily include the remaining time for a signal change.

[0179] - The name of the signal or intersection where the signal is located

[0180] - The signal or the intersection identifier (ID) at which the signal is located.

[0181] - Direction of the signal

[0182] - Current time (message creation time for transmitting signal information from signal server (205))

[0183] - Current signal status

[0184] - Remaining time until the signal changes

[0185] - Information for mapping the signal information of the signal and the location information of the signal (i.e. MapData above)

[0186]

[0187] The VRU (201) can receive signal information (S312). Through the received signal information, the VRU (201) can check the current signal status and the remaining time until the next signal is changed. Then, the VRU (201) can perform scheduling to adjust the transmission cycle of the PSM after the remaining time. Here, the scheduling may include a process of preparing for transmitting the PSM, a process of adjusting the transmission cycle of the PSM from when, and a process of determining information on how to transmit the PSM with the adjusted transmission cycle.

[0188] Additionally, as a process included in scheduling, the VRU (201) can perform an additional low-power mode by adjusting the transmission cycle of the PSM during the remaining time. For example, the VRU (201) can perform additional power savings by transmitting the PSM at a longer cycle than the PSM transmission cycle before receiving the signal information.

[0189] VRU (201) can save power used for message transmission by lengthening the transmission cycle of PSM before transmitting PSM with the adjusted transmission cycle of PSM after receiving signal information.

[0190] The VRU (201) can change the transmission cycle of the PSM (S313) at the time when the lighting of the signal (207) changes (e.g., the time when the light changes from red to green, T3). The time when the transmission cycle of the PSM is changed may not completely coincide with the time when the lighting of the signal (207) changes (T3). The transmission cycle of the PSM can be changed within a certain range of time based on T3.

[0191] In this case, the transmission cycle may be changed to be shorter than the previous transmission cycle. This is to notify the VRU (201) of road crossings more frequently.

[0192] Then, the VRU (201) can transmit the PSM with a changed transmission cycle (S314). By transmitting the PSM more frequently, the probability that surrounding vehicles can detect the presence of the VRU (201) while crossing the road can be increased.

[0193] When receiving signal information as below, VRU (201) interprets the message in which the signal information is transmitted to check the current position of the signal (207), and confirms that the current signal is a red light and that the signal will change to a green light after 45 seconds.

[0194] SignalInformationMessage::= SEQUENCE {

[0195] crosswalkName "ABC School",

[0196] crosswalkId "SEOUL123456",

[0197] crosswalkDirection "SouthToNorth",

[0198] timeStamp 1690874745, -- Epoch time

[0199] signalStatus "Red",

[0200] remainingTime 45 -- 45 seconds

[0201]

[0202] ...

[0203] }

[0204] That is, after 45 seconds, the pedestrian can actually cross the crosswalk. During the 45 seconds, the VRU (201) can lengthen the PSM transmission cycle to reduce power consumption.

[0205] In an embodiment, a VRU that receives signal information can set the vruPSMTxRateMin value to 1 Hz (PSM transmission every 1 second) and wait until the signal changes. After that, the VRU (201) can transmit PSM by adjusting the PSM transmission cycle to a short value after 45 seconds, thereby safely transmitting its location to other vehicles while the VRU (201) is crossing the road. For example, the VRU (201) can change the PSM transmission cycle to 10 Hz (PSM transmission every 100 ms), which is vruPSMTxRateMax, 45 seconds after receiving the signal information, and transmit PSM accordingly. The specific value of the PSM transmission cycle may vary depending on the system settings or the policy of the VRU (201), and the present invention does not limit it.

[0206] Additionally, the VRU (201) may change the transmission cycle of the PSM again after a preset time or a sufficient time after the VRU (201) has completed crossing the road (S314). Here, the preset time may correspond to the green light maintenance time of the signal (207), may be set to a value proportional to the moving speed of the VRU (201), or may be a time that can be set for each VRU (201) through user settings, etc. In Fig. 3, it is illustrated that the VRU (201) changes the transmission cycle of the PSM when the signal changes to red again (T4).

[0207]

[0208] FIG. 4 illustrates a flowchart of a method for controlling a V2X-based PSM transmission period according to the present invention.

[0209] Fig. 4 shows a process in which a VRU (201) adjusts a PSM transmission cycle when a remaining time indicator (209) is used in a V2X-based smart traffic management system (1).

[0210] As with Fig. 2, there is no limitation on the V2X communication method, and both V2N methods such as Uu and direct communication methods such as PC5 and DSRC are considered.

[0211] Additionally, while the process illustrated in FIG. 4 is in progress, the VRU (201) transmits PSM according to the set transmission cycle.

[0212] A remaining time indicator (209), a signal (207) and an RSU (206) can constitute road infrastructure.

[0213] The embodiment of Fig. 4 shows an embodiment in which the procedure is triggered according to a change in the signal of the signal (207) (change from red to green).

[0214] It is assumed that the signal (207) is indicating a red light (T11). More specifically, it is assumed that the signal (207) has changed from a green light to a red light (T11). In addition, it is assumed that the remaining time indicator (209) is indicating the remaining time of the red light (T12).

[0215] The process of obtaining remaining time information to display the remaining time of a signal by the remaining time indicator (209) is briefly described.

[0216] When the light changes from green to red, the signal device (207) can update the remaining time of the red light (S401). The signal device (207) can obtain information about the remaining time or duration of the red light from the signal server, or can obtain information about the remaining time or duration of the red light from the signal schedule scheduled by the signal server. Then, the signal device (207) can transmit a number to be displayed to the remaining time indicator (209) (S402). The remaining time indicator (209) can display the remaining time based on the number to be displayed received.

[0217] Then, the signal (207) can transmit a triggering message including a signal change notification and remaining time information of the changed signal (i.e., red light) to the RSU (206) (S403).

[0218] In addition, the time at which the transmission of the trigger message (S403) is triggered must be sufficient time for the VRU (201) to perform scheduling to change the transmission cycle of the PSM after receiving the signal information. That is, the signal information transmission request must be transmitted before the preparation time required to perform scheduling at the time of the signal change (after the remaining time has elapsed). That is, the signal information transmission request can be transmitted when the remaining time until the signal change is longer than the preparation time required to change the transmission cycle of the PSM.

[0219] For example, a request for signal information transmission may be transmitted 10 seconds before the remaining time, which is the point at which the signal changes, is reached, so that the VRU (201) that has received the signal information may perform scheduling to change the PSM transmission cycle for about 10 seconds. This setting is an example, and the specific value of the transmission cycle may vary depending on the system settings or the policy of the VRU (201), and the invention is not limited thereto.

[0220] RSU (206) can transmit a signal change notification including remaining time information to the V2X server (204) (S404).

[0221] Meanwhile, since the V2X server (204) obtains remaining time information from the RSU (206), a query and response procedure for remaining time information with the signal server (205) such as S309 to S310 of FIG. 3 is not necessary.

[0222] There may be three ways to transmit signal information including transmission time information to the VRU (201): i) two ways through the RSU (206), and ii) a way in which the V2X server (204) transmits directly.

[0223] Two methods via RSU (206) are described, referred to as Opt1. Opt1 can be implemented when VRU (201) is equipped with a PC5 interface.

[0224] The V2X server (204) can transmit signal information including remaining time information to the RSU (206) (S405-1). Then, the RSU (206) can transmit signal information including remaining time information to the VRU (201) (S405-2).

[0225] Alternatively, since the RSU (206) can obtain remaining time information from the signal device (207), when a trigger message (S403) is received, the RSU (206) can transmit signal information including the remaining time information to the VRU (201) (S405-2).

[0226] The method in which the V2X server (204) directly transmits signal information to the VRU (201) is called Opt2 and will be described below. Opt2 can be implemented when the VRU (201) does not have a PC5 interface and uses a Uu interface (e.g., Soft V2X VRU).

[0227] The V2X server (204) can transmit signal information including remaining time information to the VRU (201) (S405).

[0228] The VRU (201) can receive signal information (S406). Through the received signal information, the VRU (201) can check the current signal status and the remaining time until the next signal is changed. Then, the VRU (201) can perform scheduling to adjust the transmission cycle of the PSM after the remaining time. Here, the scheduling may include a process of preparing to transmit the PSM, a process of adjusting the transmission cycle of the PSM from when, and a process of determining information on how to transmit the PSM with the adjusted transmission cycle.

[0229] Additionally, as a process included in scheduling, the VRU (201) can perform an additional low-power mode by adjusting the transmission cycle of the PSM during the remaining time. For example, the VRU (201) can perform additional power savings by transmitting the PSM at a longer cycle than the PSM transmission cycle before receiving the signal information.

[0230] VRU (201) can save power used for message transmission by lengthening the transmission cycle of PSM before transmitting PSM with the adjusted transmission cycle of PSM after receiving signal information.

[0231] The VRU (201) can change the transmission cycle of the PSM (S407) at the time when the lighting of the signal (207) changes (e.g., the time when the light changes from red to green, T14). The time when the transmission cycle of the PSM is changed may not completely coincide with the time when the lighting of the signal (207) changes (T14). The transmission cycle of the PSM can be changed within a certain range of time based on T14.

[0232] In this case, the transmission cycle may be changed to be shorter than the previous transmission cycle. This is to notify the VRU (201) of road crossings more frequently.

[0233] Then, the VRU (201) can transmit PSM with a changed transmission cycle (S411). By transmitting PSM more frequently, the VRU (201) can increase the probability that surrounding vehicles can detect the presence of the VRU (201) while crossing the road.

[0234] Until the VRU (201) changes the transmission cycle, the transmission cycle of the PSM can be Transmission Timing Mode 1 or Mode 2 as described above, and the transmission cycle of the PSM can be short or long. The present invention operates regardless of the PSM transmission cycle of the VRU or whether the power saving mode is in operation until the arrival at the crosswalk.

[0235] In addition, the VRU (201) can change the transmission cycle of the PSM again after a preset time or a sufficient time after the VRU (201) has completed crossing the road (S412). Here, the preset time may correspond to the green light maintenance time of the signal (207), may be set to a value proportional to the moving speed of the VRU (201), or may be a time that can be set for each VRU (201) through user settings, etc. In Fig. 4, it is illustrated that the VRU (201) changes the transmission cycle of the PSM when the signal changes to red again (T16).

[0236] In addition, the process for displaying the remaining time of the signal of the remaining time indicator (209) according to the signal change to green of the signal (207) can be applied in the same manner to S408, S409 and S410.

[0237] However, since S401 to S407 and S411, etc., described above may be performed only when the signal light changes to red, unlike what is shown, when the signal light changes to green, transmission of the trigger message (S410) may not be performed.

[0238] When the signal changes back to red (T16), S401 to S407 and S411 described above may be performed.

[0239] Meanwhile, in the case of Opt1, the RSU (206) and VRU (201) can transmit and receive signal information out of band (Non V2X) rather than through the PC5 interface.

[0240] Meanwhile, although the description was made assuming that the VRU (201) is located at the signal (207) or the corresponding crosswalk in T13, the present invention may not require this. That is, it can be confirmed that the approach of the VRU (201) to the signal (207) does not trigger S401 to S412. That is, the V2X server (204) or the RSU (206) is configured to transmit signal information including remaining time information to the VRU (201) around the signal (207) whenever the signal of the signal (207) changes (T11, T16, etc.).

[0241]

[0242] FIG. 5 illustrates a flowchart of a method for controlling a V2X-based PSM transmission period according to the present invention.

[0243] FIG. 5 shows a process in which a VRU (201) adjusts a PSM transmission cycle when a remaining time indicator (209) is used in a V2X-based smart traffic management system (1).

[0244] As with Fig. 2, there is no limitation on the V2X communication method, and both V2N methods such as Uu and direct communication methods such as PC5 and DSRC are considered.

[0245] Additionally, while the process illustrated in FIG. 4 is in progress, the VRU (201) transmits PSM according to the set transmission cycle.

[0246] A remaining time indicator (209), a signal (207) and an RSU (206) can constitute road infrastructure.

[0247] The embodiment of Fig. 5 shows an embodiment in which the procedure is triggered according to a change in the signal of the signal (207) (change from red to green).

[0248] However, what is different from Fig. 4 is that the remaining time information is not included in the information transmitted from the signal (207) to the RSU (206) and the V2X server (204).

[0249] Accordingly, there is a difference in that S505 and S506 are added. S501 to S504 of FIG. 5 are identical to or correspond to S401 to S404 of FIG. 4, and S507 to S514 of FIG. 5 are identical to or correspond to S405 to S412 of FIG. 4, and therefore, a description thereof will be omitted. However, unlike FIG. 4, in Opt1 of FIG. 5, the RSU (206) has not acquired the remaining time information of the signal device (207), and therefore the RSU (206) cannot directly transmit signal information including the remaining time information.

[0250] Since the trigger message of S503 only includes a signal change notification, the V2X server (204) must query the signal server (205) for remaining time information of the signal. Accordingly, the V2X server (204) transmits a remaining time information request to the signal server (205) (S505), and in response, the V2X server (204) can receive a remaining time information response including the remaining time information from the signal server (205) (S506).

[0251] Meanwhile, in the case of Opt1, the RSU (206) and VRU (201) can transmit and receive signal information out of band (Non V2X) rather than through the PC5 interface.

[0252] Meanwhile, although the description was made assuming that the VRU (201) is located at the signal (207) or the corresponding crosswalk in T13, the present invention may not require this. That is, it can be confirmed that the approach of the VRU (201) to the signal (207) does not trigger S401 to S412. That is, the V2X server (204) or the RSU (206) is configured to transmit signal information including remaining time information to the VRU (201) around the signal (207) whenever the signal of the signal (207) changes (T11, T16, etc.).

[0253]

[0254] Fig. 6 illustrates a flowchart of a method for controlling a V2X-based PSM transmission cycle according to the present invention. Unlike Figs. 4 and 5, Fig. 6 illustrates an embodiment in which the approach of a VRU (201) to a signal or crosswalk is detected through a sensor (210) of a road infrastructure, thereby triggering the corresponding procedure.

[0255] The present invention can be extended to an embodiment in which, in addition to this embodiment, the procedure is triggered by detecting the approach of road infrastructure or RSU (206) to the signal (207) of VRU (201) through PSM periodically transmitted by VRU (201) (PSM includes location information, see Table 1).

[0256] Let us assume a situation where a VRU (201) is located at a signal (207) or at a crosswalk corresponding to a signal (207) (T21). The VRU (201) can transmit a VRU detection signal to a sensor (210) (S601). Although described as a VRU detection signal and its transmission, it can also be understood that the VRU (201) actually transmits a VRU detection signal, or the sensor (210) detects the VRU (201).

[0257] The sensor (210) can transmit a VRU detection signal to the RSU (206) (S602). The RSU (206) can transmit a VRU presence notification to the V2X server (204) (S603).

[0258] The V2X server (204) needs to obtain remaining time information of the signal (207). Accordingly, the V2X server (204) transmits a remaining time information request to the signal server (205) (S604), and in response, the V2X server (204) can receive a remaining time information response including remaining time information from the signal server (205) (S605).

[0259] There may be two ways to transmit signal information including transmission time information to the VRU (201): i) through the RSU (206), and ii) directly by the V2X server (204).

[0260] The method via RSU (206) is called Opt1 and will be described below. Opt1 can be implemented when VRU (201) is equipped with a PC5 interface.

[0261] The V2X server (204) can transmit signal information including remaining time information to the RSU (206) (S606-1). Then, the RSU (206) can transmit signal information including remaining time information to the VRU (201) (S606-2).

[0262] The method in which the V2X server (204) directly transmits signal information to the VRU (201) is called Opt2 and will be described below. Opt2 can be implemented when the VRU (201) does not have a PC5 interface and uses a Uu interface (e.g., Soft V2X VRU).

[0263] The V2X server (204) can transmit signal information including remaining time information to the VRU (201) (S606).

[0264] The VRU (201) can receive signal information (S607). Through the received signal information, the VRU (201) can check the current signal status and the remaining time until the next signal is changed. Then, the VRU (201) can perform scheduling to adjust the transmission cycle of the PSM after the remaining time. Here, the scheduling may include a preparation process for transmitting the PSM, a process for adjusting the transmission cycle of the PSM from when, and a process for determining information on how to transmit the PSM with the adjusted transmission cycle.

[0265] Additionally, as a process included in scheduling, the VRU (201) can perform an additional low-power mode by adjusting the transmission cycle of the PSM during the remaining time. For example, the VRU (201) can perform additional power savings by transmitting the PSM at a longer cycle than the PSM transmission cycle before receiving the signal information.

[0266] VRU (201) can save power used for message transmission by lengthening the transmission cycle of PSM before transmitting PSM with the adjusted transmission cycle of PSM after receiving signal information.

[0267] The VRU (201) can change the transmission cycle of the PSM (S608) at the time when the lighting of the signal (207) changes (e.g., the time when the light changes from red to green, T22). The time when the transmission cycle of the PSM is changed may not completely coincide with the time when the lighting of the signal (207) changes (T22). The transmission cycle of the PSM can be changed within a certain range of time based on T22.

[0268] In this case, the transmission cycle may be changed to be shorter than the previous transmission cycle. This is to notify the VRU (201) of road crossings more frequently.

[0269] Then, the VRU (201) can transmit the PSM with a changed transmission cycle. By transmitting the PSM more frequently, the probability that surrounding vehicles can detect the presence of the VRU (201) while crossing the road can be increased.

[0270] Until the VRU (201) changes the transmission cycle, the transmission cycle of the PSM can be Transmission Timing Mode 1 or Mode 2 as described above, and the transmission cycle of the PSM can be short or long. The present invention operates regardless of the PSM transmission cycle of the VRU or whether the power saving mode is in operation until the arrival at the crosswalk.

[0271] Additionally, the VRU (201) may change the transmission cycle of the PSM again after a preset time or after a sufficient time for the VRU (201) to complete crossing the road. Here, the preset time may correspond to the green light maintenance time of the signal (207), may be set to a value proportional to the moving speed of the VRU (201), or may be a time that can be set for each VRU (201) through user settings, etc.

[0272] Meanwhile, in the case of Opt1, the RSU (206) and VRU (201) can transmit and receive signal information out of band (Non V2X) rather than through the PC5 interface.

[0273]

[0274] Figure 7 illustrates the setting of an area in an environment for controlling a V2X-based PSM transmission cycle according to the present invention.

[0275] A method for determining whether a VRU (201) is crossing a crosswalk using the current location information of the VRU (201) is described. Basically, all VRUs (201) have GPS / GNSS, which is a positioning technology for determining their location. Using this, a method is proposed in which the VRU (201) periodically checks its location, and if its location is located in a pre-designated crosswalk area, it predicts or assumes that the VRU (201) will cross the crosswalk, and adjusts the PSM transmission cycle of the VRU (201). This method has no connection with a signal (207) or a signal server (205), so the accuracy of determining whether the VRU (201) is crossing a crosswalk is low, but it has the advantage that the VRU itself can adjust the PSM transmission cycle according to the location information.

[0276] The RSU (206) can be communicatively connected to a V2X server (204) and a location information server (210) via a network. The location information server (210) can store information about areas (R1, R2) around a crosswalk, which will be described below.

[0277] The areas (R1, R2) around the crosswalk can be preset. Information about the areas (R1, R2) around the crosswalk can be received from the VRU (201) at the start of the service or during the service.

[0278] Although the scope of the embodiment is exemplified as the area around a crosswalk, the invention is not limited to the application of the scope to areas such as construction sites, areas at risk of falling, areas with a high incidence of traffic accidents, areas where pedestrians are killed in traffic accidents, areas for the protection of children, areas for the protection of the elderly, and areas for the protection of the vulnerable.

[0279]

[0280] Fig. 8 illustrates a flowchart of a method for controlling a V2X-based PSM transmission period according to the present invention. Fig. 9 proposes a method for controlling a PSM transmission period using the area information illustrated in Fig. 8.

[0281] Additionally, while the process illustrated in FIG. 8 is in progress, the VRU (201) transmits PSM according to the set transmission cycle.

[0282] VRU (201) can update or receive preset area information (S810).

[0283] The preset area may include the first area (R1) or the second area (R2) described with reference to FIG. 7, but the present invention is not limited thereto.

[0284] For example, the first region (R1) may include a surrounding area including a crosswalk. The preset region information includes information on the area waiting for a pedestrian signal and the area marked as a crosswalk on the road, and may be expressed as, for example, polygon coordinates in GeoJSON format.

[0285] The VRU (201) can update its current location (S820). In addition, the VRU (201) can compare its current location with a preset area to determine whether the VRU (201) is currently located within the preset area (S830).

[0286] If VRU (201) is located within the preset area, it starts a timer from the time of location confirmation to activate T in the area. duration You can check whether it has been positioned continuously (S840). T duration The value can be determined by the system or settings.

[0287] For example, if the preset area is R1 around the crosswalk shown in Fig. 7, the VRU (201) is in R1 for a certain period of time (T duration ) If the pedestrian remains for more than this period, it can be judged that the pedestrian intends to cross the crosswalk or is in the process of crossing the crosswalk.

[0288] For example, if the preset area is a child protection zone, the VRU (201) will be in R1 for a certain period of time (T duration) If the VRU (201) stays for more than this period, it can be determined that the VRU (201) is on its way to or from school or is active in the vicinity.

[0289] If VRU (201) is not located within the preset area, or T is not present in the area duration If the VRU (201) is not continuously located during the period, the VRU (201) can maintain the PSM transmission cycle (S850). After that, the VRU (201) can return to S820 and repeat the procedure, such as updating its location information.

[0290] VRU (201) is located within the preset area and T in the preset area. duration If the VRU (201) remains in the preset area, it may be determined or determined that the transmission cycle of the PSM needs to be adjusted (S860). More specifically, while the VRU (201) remains in the preset area, the preset area may be an area with a high frequency of traffic accidents or a high level of damage, so the PSM containing the location information of the VRU (201) should be transmitted more frequently so that surrounding vehicles (202) can easily detect the presence of the VRU (201).

[0291] Meanwhile, although not shown, one more condition may be added to determine or determine whether it is necessary to adjust the transmission cycle of the PSM of the VRU (201). Referring to FIG. 7, not only the region (R1) but also the region (R2) is shown. The region (R2) is an area around the region (R1). The VRU (201) may additionally determine whether it has received a BSM from a surrounding vehicle (202) in a second region (R2) around the preset region (R1). That is, the VRU (201) may transmit a BSM to the preset region (R1) for a preset time (T duration ) and also in the case where BSM is received in the area (R2) before being located in the preset area (R1), it can be judged or determined that it is necessary to adjust the PSM transmission cycle to a shorter period (S860).

[0292] Then, VRU (201) can adjust the PSM transmission cycle to be short (S870).

[0293] At this time, the application of the adjusted transmission period can be performed immediately. That is, the VRU (201) can transmit the PSM according to the adjusted transmission period.

[0294] The VRU (201) may transmit PSM according to a controlled transmission cycle until a preset time has elapsed or the vehicle leaves a preset area. For example, the preset time may be sufficient time to cross a crosswalk.

[0295] VRU (201) can determine whether a preset time has passed or a preset area has been left (S880).

[0296] When a preset time has elapsed or the preset area has been exceeded, the VRU (201) can adjust the PSM transmission cycle to a longer length again (S890). At this time, the transmission cycle can be adjusted to a transmission cycle set before the transmission cycle was adjusted in S870, or to a transmission cycle according to an existing system policy or setting.

[0297] Meanwhile, the description of Fig. 8 was about a method for VRU (201) alone to adjust the PSM transmission cycle based on its current location and received preset area information.

[0298] As another example, in the environment or system illustrated in FIG. 7, the VRU (201) is located in a preset area (R1, R2) and / or at a preset time (T duration ) can be set to receive a message from the RSU (206) when located in a preset area (R1, R2).

[0299] The VRU (201) informs its surroundings of its location through periodic PSM transmission, which the RSU (206) can receive. The RSU (206) can receive information about preset areas (R1, R2) from the location information server (210) in advance or periodically. Accordingly, the RSU (206) can determine whether the VRU (201) is located in the preset area for a preset period of time. If the RSU (206) determines that the VRU (201) is located in the preset area for a preset period of time, the RSU (206) can transmit a transmission period adjustment command to the VRU (201). The VRU (201) that receives the transmission period adjustment command can adjust its own PSM transmission period.

[0300] Meanwhile, instead of the RSU (206), the V2X server (204) can generate the above judgment and transmission cycle control command and transmit it to the VRU (201). In this case, the V2X server (204) can obtain the location information of the VRU (201) because it is connected to the VRU (201) through an Internet network (203) via Uu communication such as LTE / 5G as well as the PSM transmitted by the VRU (201). The V2X server (204) can determine whether the VRU (201) is located in the preset area for a preset period of time based on the obtained location information of the VRU (201) and information about the preset area.

[0301] Likewise, the V2X server (204) can determine whether the VRU (201) has left the preset area or whether a preset time has passed since the transmission period adjustment command was transmitted. If the V2X server (204) determines that the VRU (201) has left the preset area or whether a preset time has passed since the transmission period adjustment command was transmitted, the V2X server (204) can generate a PSM transmission period adjustment command and transmit it to the VRU (201). The VRU (201) that receives the transmission period adjustment command can adjust its own PSM transmission period.

[0302]

[0303] FIG. 9 illustrates a flowchart of a method for controlling a V2X-based PSM transmission period according to the present invention.

[0304] FIG. 9 proposes a method that combines a method for controlling a PSM transmission period using the area information shown in FIG. 7 and a method for controlling a PSM transmission period using the signal information shown in FIGS. 3 to 6.

[0305] Additionally, while the process illustrated in FIG. 9 is in progress, the VRU (201) transmits PSM according to the set transmission cycle.

[0306] S901 to S905 of FIG. 9 are the same as S810 to S840 and S860 of FIG. 8, S907 of FIG. 9 is the same as S850 of FIG. 8, and S911 to S913 of FIG. 9 are the same as S870 to S890 of FIG. 8. Therefore, to avoid redundant explanation, the explanation will be omitted and reference will be made to the explanation of FIG. 8.

[0307] In Fig. 9, we propose a method to further reduce power consumption compared to the method of Fig. 8 by more precisely specifying the point in time to start transmitting PSM with an adjusted PSM transmission cycle.

[0308] Accordingly, the VRU (201) can detect whether signal information has been received or whether the VRU (201) is crossing a road within a preset area (S906). The signal information may include information on the remaining time for a signal change, as described above. If the VRU (201) receives signal information or detects that the VRU (201) is crossing a road within a preset area, the VRU (201) can perform scheduling to adjust the PSM transmission cycle (S908).

[0309] Whether or not a pedestrian is crossing the road within a preset area can be determined through the current location of the VRU (201). This is to adjust the frequency of PSM transmission so that it can be transmitted immediately if the current location of the pedestrian is determined to be on the road on which the vehicle (202) is driving, regardless of the reception of signal information. This is to adjust the transmission cycle of PSM to encompass both cases where a VRU that has not received signal information for any reason proceeds with a normal crossing when the signal changes from red to green, and cases where a VRU is located on the road at a red light even before the signal changes, for example, jaywalking.

[0310] At this time, if signal information is received, the VRU (201) may begin transmitting PSM with an adjusted transmission cycle after the remaining time for signal change according to the signal information has elapsed. In addition, if the VRU (201) determines that the VRU (201) is crossing a road, the VRU (201) may immediately begin transmitting PSM with an adjusted transmission cycle.

[0311] Accordingly, the VRU (201) can detect whether the remaining time for the signal change has elapsed or whether the VRU (201) is crossing the road (S909).

[0312] When the remaining time for a signal change has elapsed or when it is detected that the VRU (201) is crossing the road, the VRU (201) can adjust the PSM transmission cycle (S911).

[0313] If the remaining time for the signal change has not elapsed or if the VRU (201) is not detected to be crossing the road, the VRU (201) can maintain the PSM transmission cycle (S910).

[0314]

[0315] Figure 10 shows a comparison of the V2X-based PSM transmission cycle according to the present invention and the prior art.

[0316] In (a) to (f) of Fig. 10, P1, which represents the road crossing time of the VRU, means the time at which the VRU actually crossed the road. In (a) to (f) of Fig. 10, the upward arrow represents the transmission of PSM.

[0317] In the case of (a) of Fig. 10, the transmission (cycle) of PSM is shown when the PSM transmission cycle is fixed to 1 Hz according to the prior art. In this case, the VRU transmits PSM once per second, and transmits at a constant cycle regardless of the VRU's road crossing. In this case, since the PSM is transmitted at a relatively slow cycle while crossing the road, there is a disadvantage that surrounding vehicles may not be able to recognize the VRU in a timely manner. In other words, there is a disadvantage that the safety of the VRU may not be guaranteed while crossing the crosswalk.

[0318] In the case of (b) of Fig. 10, the PSM transmission cycle is fixed at 10 Hz according to the conventional technology. In this case, the VRU transmits PSM once every 100 ms across the entire area. While the VRU can transmit PSM relatively safely while crossing a road, it has the disadvantage of consuming a lot of power in the VRU because it transmits PSM too frequently even when not crossing a road.

[0319] In the case of (c) of Fig. 10, the transmission (cycle) of PSM is shown when using a button-type pedestrian signal according to the present invention. It corresponds to the embodiment illustrated in Fig. 3. In this case, from the time when the VRU presses the button conveying the intention to cross the road, and during the period (remaining time) when the signal information is received and the signal actually changes from red to green, the VRU transmits PSM at a relatively long cycle (e.g., 1 Hz) as before. Thereafter, from the time when the signal changes to the time when the signal is maintained, the VRU transmits PSM at 10 Hz. This has the advantage of reducing power consumption by transmitting PSM at a long cycle in a relatively safe location, and increasing safety by frequently transmitting PSM when crossing a relatively dangerous road. In the embodiment, the PSM cycle is expressed as being adjusted short until the time when the signal changes from green to red again, but if the location information of the VRU is used together as in (e), the transmission cycle of the PSM can be adjusted again the moment the VRU exits the crosswalk.

[0320] Fig. 10(d) shows the transmission (cycle) of PSM when the VRU according to the present invention uses a red light remaining time indicator. In this case, similar to Fig. 10(c), the signal information is received and the PSM transmission cycle is adjusted short after a preparation time. Similar to Fig. 10(c), it has the advantage of increasing safety by frequently transmitting PSM while the VRU is crossing the crosswalk, and it has the advantage of reducing power consumption by readjusting the PSM transmission cycle when the signal changes from green to red.

[0321] Figure 10(e) illustrates the transmission (cycle) of PSM when using the location information of the VRU according to the present invention. In this case, the point in time when the PSM transmission cycle is adjusted to be short is when the VRU enters the area surrounding the crosswalk (e.g., R1 in Figure 5). Thereafter, while remaining in the area surrounding the crosswalk, the VRU can frequently transmit its location to vehicles by shortening the PSM cycle, thereby enhancing safety. After this, when exiting the crosswalk area before the signal changes from green to red, the VRU can adjust the PSM transmission cycle again to reduce power consumption.

[0322] Figure 10 (f) shows the transmission (cycle) of PSM when using the button-type pedestrian signal (or red light remaining time indicator) according to the present invention and the location information of the VRU together.

[0323] Accordingly, the VRU can more accurately recognize that the VRU has started to cross the crosswalk, and the VRU can adjust the PSM transmission cycle at the precise timing. That is, the approximate time when the VRU starts to cross can be confirmed based on the signal information, and the PSM can be transmitted while confirming that the VRU has actually started to cross based on the current location of the VRU. In addition, the PSM transmission cycle can be adjusted by confirming that the VRU has completed crossing by considering the location of the VRU and the remaining time of the green light. Accordingly, it can be confirmed that the most power-efficient embodiment is achieved by adjusting the PSM transmission cycle to be short and transmitting PSM accordingly only during P1 or during the time interval most similar to P1.

[0324]

[0325] As previously explained, since VRUs typically participate in V2X services through mobile devices such as smartphones, power consumption varies significantly depending on the frequency of communication. To provide safer services using V2X, it is necessary to share one's location as frequently as possible and frequently receive location information transmitted by other V2X devices to predict collisions or hazards using the latest information. However, frequent data transmission consumes the limited battery resources of mobile devices, so there is a problem with unconditionally transmitting and receiving data frequently. To solve this problem, power consumption can be reduced by increasing the transmission cycle of the PSM transmitted and received by the VRU, but this can conversely pose a safety issue.

[0326] The present invention reduces power consumption by adjusting the transmission cycle of PSM to be relatively long when the VRU is located away from a sidewalk or road, which is a relatively safe location, and can adjust the PSM transmission cycle to be short by detecting a pedestrian crossing the road.

[0327] This reduces overall power consumption and enables quicker response to dangerous situations.

[0328] Fig. 11 illustrates a block diagram of a device for controlling the PSM transmission cycle of the present invention.

[0329] The device (201) corresponds to the VRU described above.

[0330] The device (201) may include a transceiver (2100) and a processor (2200). The transceiver (2100) may be configured to receive signal information from an RSU (206) or a V2X server (204), or to transmit a PSM.

[0331] The processor (2200) may be configured to receive signal information including a remaining time until a signal change from the RSU (206) or the V2X server (204) through the transceiver (2100). The processor (2200) may be configured to perform scheduling for adjusting a transmission period of the PSM according to the received signal information. In addition, the processor (2200) may be configured to transmit the PSM through the transceiver (2200) according to an adjusted transmission period according to the scheduling for adjusting the transmission period of the PSM.

[0332] As another embodiment, the processor (2200) may be configured to periodically update the current location information of the device (201). The processor (2200) may be configured to perform scheduling to adjust the transmission period of the PSM based on the updated current location. Furthermore, the processor (2200) may be configured to transmit the PSM according to the adjusted transmission period.

[0333] For configurations or operations of the device or VRU (201) not described with reference to FIG. 11, refer to the contents described with reference to FIGS. 3 to 10. That is, the contents of the configuration or operation of the VRU (201) described with reference to FIGS. 3 to 10 may also be applied to the device (201) of FIG. 11.

[0334]

[0335] In addition, as another aspect of the present invention, the operation of the proposal or invention described above may be implemented, performed or executed by a “computer” (a comprehensive concept including a system on chip (SoC) or a (micro) processor, etc.), or may be provided as a code or a computer-readable storage medium storing or including the code or a computer program product, and the scope of the present invention may be extended to the code or the computer-readable storage medium storing or including the code or the computer program product.

[0336]

[0337] The detailed description of the preferred embodiments of the present invention disclosed above has been provided to enable those skilled in the art to implement and practice the present invention. While the above description has been made with reference to preferred embodiments of the present invention, those skilled in the art will appreciate that various modifications and variations of the present invention, as defined by the following claims, are possible. Accordingly, the present invention is not intended to be limited to the embodiments disclosed herein but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A method for controlling the transmission cycle of a PSM (personal safety message) for V2X communication, wherein the method is performed by a VRU (Vulnerable Road User) terminal. A step of receiving signal information including the remaining time until a signal change of a signal from an RSU (Road Side Unit) or a V2X server; A step of performing scheduling to adjust the transmission cycle of PSM according to the received signal information; and A method comprising the step of transmitting the PSM according to an adjusted transmission cycle according to the above scheduling.

2. A method comprising, in the first paragraph, a step of restoring the adjusted transmission period according to the scheduling to the transmission period before adjusting or the preset transmission period after a preset time has elapsed after adjusting the transmission period of the PSM.

3. In the first paragraph, a step of setting the transmission cycle of the PSM for the remaining time until the signal change to be greater than the transmission cycle before receiving the signal information within a preset range; and A method comprising the step of transmitting PSM according to the set transmission cycle during the remaining time.

4. In paragraph 1, the transmission of the signal information of the RSU or the V2X server is A method triggered by any one of the following: the location of the VRU terminal, detection of a push of a button installed around the signal, or a change in the signal.

5. In paragraph 1, the transmission of the signal information of the RSU or the V2X server is triggered according to a signal change, A method in which a trigger message for requesting transmission of the above signal information is transmitted when the remaining time until the signal change is longer than the preparation time required to change the transmission cycle of the PSM.

6. In paragraph 1, the signal information is: The name of the above signal or the intersection where the above signal is located, The above signal or the intersection identifier (ID) at which the above signal is located, The direction of the above signal, Current time, Current status of the above signal, The remaining time until the signal change of the above signal, or A method comprising at least one of signal information of the signal device and information for mapping location information of the signal device.

7. A method for controlling the transmission cycle of a PSM (personal safety message) for V2X communication, wherein the method is performed by a VRU (Vulnerable Road User) terminal. Steps for periodically updating the current location information of the above VRU terminal: A step of performing scheduling to adjust the transmission cycle of the PSM based on the updated current location; and A method comprising the step of transmitting the PSM according to the adjusted transmission cycle.

8. In paragraph 7, the start of the PSM transmission according to the adjusted transmission cycle is A method determined based on signal information received from an RSU or V2X server or the updated current location.

9. In paragraph 7, after the remaining time until the signal change included in the signal information received from the RSU or V2X server has elapsed, or after detecting that the VRU terminal begins to cross the crosswalk based on the updated current location, A method comprising the step of transmitting the PSM at the above-described controlled transmission cycle.

10. In paragraph 7, A method comprising a step of restoring the adjusted transmission cycle according to the scheduling to the transmission cycle prior to adjusting the transmission cycle or to the preset transmission cycle, if a preset time has elapsed after adjusting the transmission cycle of the PSM or if it is determined that the VRU terminal has left the crosswalk area based on the updated current location.

11. In the 7th paragraph, the step of performing scheduling to control the transmission cycle of the PSM is as follows: A method comprising the step of performing scheduling to adjust the transmission period of the PSM according to the updated current location falling within a first area around a crosswalk for a preset time.

12. In the 7th paragraph, the step of performing scheduling to control the transmission cycle of the PSM is as follows: A step of receiving a BSM (Basic Safety Message) from a surrounding vehicle in a second area around a crosswalk, and performing scheduling to adjust a transmission cycle of the PSM according to the updated current location belonging to a first area around the crosswalk for a preset time, A method wherein the second region includes a surrounding region of the first region.

13. A method according to claim 7, further comprising a step of receiving settings for a first area or a second area around a crosswalk.

14. A device for controlling the transmission cycle of PSM (personal safety message) for V2X communication. including a transceiver and a processor, The above processor receives signal information including the remaining time until a signal change from an RSU (Road Side Unit) or a V2X server through the above transceiver, Perform scheduling to adjust the transmission cycle of PSM according to the received signal information, and A device configured to transmit the PSM according to an adjusted transmission cycle according to the above scheduling.

15. A device for controlling the transmission cycle of PSM (personal safety message) for V2X communication. including a transceiver and a processor, The above processor periodically updates the current location information of the device, Perform scheduling to adjust the transmission cycle of the PSM based on the updated current location, and A device configured to transmit the PSM according to the above-described controlled transmission cycle.

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