JP7825976B2 - Drive recorder and recording method - Google Patents

Description

The present invention relates to a drive recorder, a drive recorder system, and a recording method for a drive recorder.

A drive recorder records image information from a camera installed in the vehicle onto a recording medium when an event occurs, such as abnormal acceleration being applied to the vehicle.

Meanwhile, technology has been developed to install an on-board device in each vehicle and use the on-board device to drive multiple vehicles in a convoy. Patent Document 1 below is an example of a disclosure of drive recorder-related technology related to platooning.

Japanese Patent Application Laid-Open No. 2019-144992

There is room for improvement in drive recorder-related technology suitable for platooning. There is a need for the development of technology that can perform effective recording (video recording) in connection with platooning.

The present invention aims to provide a drive recorder, drive recorder system, and drive recorder recording method that can perform effective recording (video recording) in connection with platooning.

The drive recorder of the present invention is mounted on a target vehicle included in a group of vehicles traveling in a convoy, and includes an image information acquisition unit that acquires image information based on the results of photography by a camera installed on the target vehicle, an event detection unit that detects whether one or more types of events have occurred, and a recording control unit that performs event recording processing that sets an event recording period when the occurrence of any of the events is detected and records the image information during the event recording period on a specified recording medium. In this drive recorder, the one or more types of events include specific events unique to the convoy.

The drive recorder system of the present invention includes a drive recorder mounted on each of multiple vehicles in a platoon that travels in a convoy. Each drive recorder includes an image information acquisition unit that acquires image information based on the results of photography by a camera installed in the vehicle in the convoy on which the drive recorder is mounted; an event detection unit that detects whether one or more types of events have occurred; and a recording control unit that performs event recording processing that sets an event recording period when the occurrence of any event is detected and records the image information during the event recording period on a specified recording medium. In the drive recorder system, when the occurrence of any event is detected in any of the drive recorders, the event recording processing is executed in each drive recorder.

The present invention makes it possible to provide a drive recorder, a drive recorder system, and a recording method for a drive recorder that can perform effective recording (video recording) in connection with platooning.

1 is a schematic top view of a plurality of vehicles according to an embodiment of the present invention; 1 is a diagram illustrating the overall configuration of a system according to an embodiment of the present invention. 1 is a schematic top view of a plurality of vehicles according to an embodiment of the present invention; 1 is a configuration diagram of an in-vehicle device according to an embodiment of the present invention; 1 is a diagram showing a state in which a plurality of cameras are installed on a vehicle according to an embodiment of the present invention; FIG. 2 is a diagram illustrating an outline of vehicle information generated by each in-vehicle device according to the embodiment of the present invention. 3 is a diagram listing processes that can be executed by a main control unit of an in-vehicle device according to an embodiment of the present invention. FIG. FIG. 2 is a functional block diagram of a main control unit in the in-vehicle device according to the embodiment of the present invention. 3 is a flowchart illustrating an operation of the system related to the occurrence of an event according to an embodiment of the present invention. FIG. 10 is an explanatory diagram of an event occurrence period according to an embodiment of the present invention. 10 is a diagram showing how a signal is transmitted to another in-vehicle device when an event occurrence is detected in one in-vehicle device according to an embodiment of the present invention; FIG. FIG. 3 is an explanatory diagram of information recorded on a recording medium in an event recording process according to an embodiment of the present invention. FIG. 10 is an explanatory diagram of a vehicle number increase event in which the number of vehicles forming a platoon increases, according to an example (EX1) belonging to an embodiment of the present invention. FIG. 10 is an explanatory diagram of a vehicle number reduction event in which the number of vehicles forming a platoon is reduced, in accordance with an example (EX2) of an embodiment of the present invention. FIG. 10 is an explanatory diagram of an order change event in which the driving order of a group of vehicles forming a platoon is changed, in an example (EX3) according to an embodiment of the present invention. FIG. 10 is an explanatory diagram of a convoy cut-in event in which a general vehicle cuts in on a convoy, in accordance with an example (EX4) of an embodiment of the present invention.

Examples of embodiments of the present invention will be described in detail below with reference to the drawings. In each of the referenced drawings, identical parts are given the same reference numerals, and duplicate explanations of identical parts will generally be omitted. For the sake of simplicity, this specification may use symbols or reference numerals that refer to information, signals, physical quantities, components, etc., and omit or abbreviate the names of the information, signals, physical quantities, components, etc. that correspond to the symbols or reference numerals. For example, the surrounding information detection unit referred to by "30" below (see Figure 4) may be written as surrounding information detection unit 30 or abbreviated as detection unit 30, but they all refer to the same thing.

Figure 1 is a schematic top view of multiple vehicles according to an embodiment of the present invention. A platoon is formed (in other words, composed) by multiple vehicles. In this embodiment, forming a platoon is synonymous with organizing a platoon. Each vehicle forming the platoon will be specifically referred to by the symbol "CR." Furthermore, each vehicle forming the platoon may be referred to as a platoon-forming vehicle. A vehicle CR may be any type of automobile. A vehicle CR is typically assumed to be a cargo transport vehicle (truck). However, a vehicle CR may be any type of vehicle, including an electric cart or electric wheelchair. Of the vehicles CR forming the platoon, the vehicle CR traveling at the front will be referred to as the leading vehicle, the vehicle CR traveling at the rear will be referred to as the rearmost vehicle, and each of the other vehicles CR will be referred to as an intermediate vehicle. The intermediate vehicles and the rearmost vehicle will be collectively referred to as the following vehicles. The number of vehicles CR forming the platoon is represented by n. n is any integer greater than or equal to 2. The number of intermediate vehicles is (n-2). When "n = 2", there are no intermediate vehicles. Below, unless otherwise specified, it is assumed that "n ≥ 3". Note that when a platoon moves from a first point to a second point by moving straight, the direction from the first point to the second point corresponds to the forward direction.

An on-board device 1 is mounted on each vehicle CR. Figure 1 shows a schematic diagram of the on-board device 1 mounted on each vehicle CR (the same applies to Figure 3 described below). Referring to Figure 2, the system SYS is made up of a total of n on-board devices 1 mounted on n vehicles CR forming the platoon. When it is necessary to distinguish between the n vehicles CR, the i-th vehicle CR of the n vehicles CR will be specifically referred to as vehicle CR[i] (i is an integer), as shown in Figure 3. When it is necessary to distinguish between the n on-board devices 1, the on-board device 1 mounted on vehicle CR[i] will be specifically referred to as on-board device 1[i] (see also Figure 2).

In the platoon, one of the vehicles CR[1] to CR[n] functions as the reference vehicle. Here, the leading vehicle is considered to be the reference vehicle. However, any of the following vehicles may also function as the reference vehicle. Of the vehicles CR[1] to CR[n], vehicles other than the reference vehicle are sometimes referred to as non-reference vehicles. The on-board device 1 mounted on the reference vehicle can perform processes related to the entire platoon (for example, the route setting process described below) on behalf of the on-board devices 1[1] to 1[n].

In the system SYS, multiple vehicles CR travel in a convoy. Platooning refers to multiple vehicles CR traveling in a convoy. In the system SYS, the multiple vehicles CR move autonomously (autonomously travel), and the convoy travel of the multiple vehicles CR is controlled by multiple on-board devices 1 to achieve this. From this perspective, the system SYS can be referred to as a convoy travel control system. However, as will become clear from the explanation below, each on-board device 1 functions as a drive recorder suitable for platooning. Here, a drive recorder suitable for platooning can be said to be an information recording device that can record information recorded by a general drive recorder and information specific to platooning. For this reason, the system SYS can also be referred to as a convoy travel drive recorder system.

Each in-vehicle device 1 may be connected to a server device 2 for two-way communication via a predetermined communication network NET, which may include a mobile communication network, a local area network, the Internet, etc. The server device 2 is a computer device connected to the communication network NET. The server device 2 may be composed of two or more computer devices. The server device 2 may also be configured using cloud computing. The server device 2 can be a component of the system SYS. However, the presence of the server device 2 is not essential to the system SYS.

Each vehicle CR has a power source, which generates driving force to propel the vehicle CR. The power source generates driving force based on a specified fuel (e.g., fossil fuel, hydrogen), electrical energy, etc. In the following, in this embodiment, the power source will be assumed to include a motor that generates driving force based on electrical energy, as an example.

Figure 4 shows the configuration of the in-vehicle device 1. The configuration of each in-vehicle device 1 included in the system SYS is the same among the multiple in-vehicle devices 1 (although it may differ in detail). For the sake of concreteness, we will focus on one vehicle CR out of the multiple vehicles CR and explain the configuration of the in-vehicle device 1 installed in the focused vehicle CR. The focused vehicle CR may be referred to as the focused vehicle CR or simply the focused vehicle as necessary.

The in-vehicle device 1 comprises a main control unit 10, a driving information detection unit 20, a surrounding information detection unit 30, a GPS processing unit 40, an acceleration sensor 50, a memory unit 60, and a recording medium 70. However, all or any part of the driving information detection unit 20, surrounding information detection unit 30, GPS processing unit 40, acceleration sensor 50, memory unit 60, and recording medium 70 may be understood as devices that are not included in the components of the in-vehicle device 1 but are connected to the in-vehicle device 1. The actuator unit 80 is driven and controlled by the main control unit 10. Here, the actuator unit 80 is understood to be a device that is not included in the components of the in-vehicle device 1 but is connected to the in-vehicle device 1. However, it is also possible to understand the actuator unit 80 as being included in the components of the in-vehicle device 1.

The main control unit 10 includes, as hardware resources, an arithmetic processing unit 11 including a CPU (Central Processing Unit) and GPU (Graphics Processing Unit), an internal memory 12, and a communication processing unit 13 for realizing two-way communication with a counterpart device. The internal memory 12 includes non-volatile memory such as ROM (Read Only Memory) or flash memory, and volatile memory such as RAM (Random Access Memory). The counterpart devices for the in-vehicle device 1 installed in the target vehicle CR include the in-vehicle devices 1 (main control unit 10) installed in each vehicle CR other than the target vehicle CR, and may also include a server device 2.

Communication between an in-vehicle device 1 installed in one vehicle and an in-vehicle device 1 installed in another vehicle is specifically referred to as inter-vehicle communication. Inter-vehicle communication may be realized by an inter-vehicle communication system called CVSS (Connected Vehicle Support Systems). Inter-vehicle communication may be realized via a communication network NET or via a server device 2. Any information acquired or handled by any in-vehicle device 1 may be transmitted to any other in-vehicle device 1 via inter-vehicle communication, and the any information may be commonly recognized by all in-vehicle devices 1. Various notifications described below may be made via inter-vehicle communication.

In the main control unit 10, the calculation processing unit 11 may execute a program stored in the internal memory 12 or the memory unit 60 to realize each of the functional blocks described below. The main control unit 10 may be configured as a combination of multiple ECUs (Electronic Control Units) installed in the vehicle CR. Furthermore, some or all of the processing performed by the main control unit 10 may be realized by a mixture of software and hardware. Furthermore, some or all of the processing performed by the image processing device may be realized by semiconductor integrated circuits such as ASICs (application specific integrated circuits), FPGAs (field-programmable gate arrays), and CPLDs (Complex Programmable Logic Devices). The image processing device here is a device included in the system SYS and may be a device internal to the main control unit 10.

The driving information detection unit 20 consists of multiple measuring devices installed on the vehicle CR, and detects and acquires driving information using each measuring device. The driving information detection unit 20 of the target vehicle CR detects and acquires driving information about the target vehicle CR.

The driving information is information that represents the driving state of the vehicle CR. Specifically, the driving information includes vehicle speed information that represents the speed (driving speed) of the vehicle CR, steering angle information that represents the steering angle (steering angle) of the vehicle CR, and acceleration/deceleration information that represents the acceleration and deceleration state of the vehicle CR. The acceleration/deceleration information may include brake information that represents the control amount (operation amount) of the brakes of the vehicle CR. Note that the driving information may also include various information other than the various types of information described above (such as the operation amount of the throttle). The driving information is acquired sequentially at a predetermined cycle, and the acquired driving information is output sequentially to the main control unit 10.

The surrounding information detection unit 30 uses sensors for observing the surroundings of the vehicle CR to detect and acquire surrounding information representing the state of the surroundings of the vehicle CR (in other words, surrounding environment information representing the surrounding environment of the vehicle CR). The detection unit 30 for the target vehicle CR detects and acquires surrounding information representing the state of the surroundings of the target vehicle CR. The detection unit 30 is equipped with a camera 31, which is an image sensor, and a distance measurement sensor 32 as sensors for observing and detecting the surrounding state (surrounding environment) of the vehicle CR. The surrounding information is acquired sequentially at a predetermined interval, and the acquired surrounding information is output sequentially to the main control unit 10. The surrounding information includes image information and distance measurement information, which will be described below.

In the target vehicle CR, the camera 31 is installed at a predetermined position on the target vehicle CR and captures images of the area around the target vehicle CR. In the target vehicle CR, the camera 31 has a capture area (field of view) based on the position of the target vehicle CR and generates image information representing the captured image within the capture area. The image captured by the camera 31 is sometimes referred to as a camera image. Therefore, the image information generated by the camera 31 is image information representing a camera image. The capture area of the camera 31 in the target vehicle CR may include the area in front of, behind, to the right, and to the left of the target vehicle CR. Here, as shown in FIG. 5, in each vehicle CR, the camera 31 includes a front camera 31F that captures the area in front of the vehicle CR, a rear camera 31B that captures the area behind the vehicle CR, a right camera 31R that captures the area to the right of the vehicle CR, and a left camera 31L that captures the area to the left of the vehicle CR. However, the camera 31 may also include only the front camera 31F. Alternatively, the camera 31 may include only a front camera 31F and a rear camera 31B.

In the target vehicle CR, the distance measurement sensor 32 is installed at a predetermined position on the target vehicle CR and generates and outputs distance measurement information by performing distance measurements. In the target vehicle CR, distance measurement detects the distance between the target vehicle CR and a three-dimensional object (a three-dimensional object) located around the target vehicle CR, and also detects the orientation of the three-dimensional object as viewed from the target vehicle CR. These detection results are included in the distance measurement information output from the distance measurement sensor 32. In the target vehicle CR, the main control unit 10 can generate a two-dimensional map showing the presence of three-dimensional objects around the target vehicle CR based on the distance measurement information. Three-dimensional objects from the target vehicle CR's perspective include vehicles CR other than the target vehicle CR, as well as obstacles different from the vehicle CR.

The ranging sensor 32 may be configured as a LIDAR (Light Detection and Ranging) sensor that measures distance using light, or as a radar sensor that measures distance using radio waves. The ranging sensor 32 may also be configured as a combination of LIDAR and radar.

The GPS processing unit 40 receives signals from multiple GPS satellites that form the GPS (Global Positioning System) and generates GPS position information based on the received signals. For the target vehicle CR, the GPS position information generated by the GPS processing unit 40 represents the current location of the target vehicle CR using longitude and latitude. The GPS position information is generated sequentially at a predetermined interval, and the generated GPS position information is sequentially output to the main control unit 10.

The acceleration sensor 50 detects acceleration acting on the vehicle CR in a predetermined axial direction, and generates and outputs the acceleration detection results as G-sensor information. The acceleration sensor 50 may detect acceleration in two mutually orthogonal axial directions, or may detect acceleration in three mutually orthogonal axial directions. In the target vehicle CR, the acceleration sensor 50 generates and outputs G-sensor information for the target vehicle CR. The G-sensor information is generated sequentially at a predetermined cycle, and the generated G-sensor information is output sequentially to the main control unit 10.

The memory unit 60 is made of a non-volatile recording medium and records and stores various information. Map information 61 and a platooning program 62 are recorded and stored in the memory unit 60. The memory unit 60 may be provided with separate memory (map information storage unit) for recording and storing the map information 61 and memory for recording and storing the platooning program 62. The map information 61 represents a map of the area in which the vehicles CR are expected to travel. The platooning program 62 is a program executed by the processing unit 11 when multiple vehicles CR are platooning; therefore, platooning is achieved through the execution of the program 62. The map information 61 or the platooning program 62 may be downloaded from the server device 2.

The recording medium 70 is a non-volatile recording medium. The recording medium 70 is a recording medium for the drive recorder, and records mainly image information of camera images under the control of the main control unit 10. Hereinafter, the image information of camera images may also be referred to as camera image information.

The actuator unit 80 is equipped with various actuators for driving the vehicle CR in the desired direction and for accelerating, decelerating, or stopping the vehicle CR. Specifically, the actuator unit 80 is equipped with a motor that generates the driving force, as well as a steering actuator that operates the steering of the vehicle CR and a brake actuator that operates the brakes of the vehicle CR. Note that when the driving force is generated using fuel, an engine is provided in the actuator unit 80.

The vehicle information shown in Figure 6 is generated in each in-vehicle device 1. The vehicle information for the noted vehicle CR includes driving information, surrounding information, GPS position information, and G-sensor information for the noted vehicle CR, and further includes destination information indicating the destination of the noted vehicle CR. The destination of the noted vehicle CR is set in advance by the driver or administrator of the noted vehicle CR. The destination of the noted vehicle CR may also be set in the in-vehicle device 1 of the noted vehicle CR based on a signal transmitted from the server device 2 to the in-vehicle device 1 of the noted vehicle CR.

In the following, for a given in-vehicle device 1, the vehicle CR in which it is installed will be referred to as the "own vehicle," and other vehicles CR will be referred to as "other vehicles."

Figure 7 lists the main processes that can be executed by the main control unit 10.

The main control unit 10 executes the host vehicle information acquisition process. The host vehicle information acquisition process is executed for each in-vehicle device 1. In the host vehicle information acquisition process, the main control unit 10 acquires host vehicle information, which is vehicle information about the host vehicle (see Figure 6).

The main control unit 10 executes the other vehicle information acquisition process. The other vehicle information acquisition process is executed for each in-vehicle device 1. In the other vehicle information acquisition process, the main control unit 10 acquires other vehicle information, which is vehicle information about other vehicles (see Figure 6), via vehicle-to-vehicle communication. If there are multiple other vehicles, other vehicle information may be acquired for each other vehicle.

The main control unit 10 executes the route setting process. The route setting process may be executed by the main control unit 10 of one of the on-board devices 1[1] to 1[n], and in this example, the route setting process is performed by the main control unit 10 of the on-board device 1 installed in the reference vehicle. The route setting process sets the planned travel route of the convoy based on the current location of the convoy, map information 61, and the destination of the convoy.

The current location of the platoon coincides with the current location of the reference vehicle. The destination of the platoon coincides with the destination of the reference vehicle. In this embodiment, unless otherwise specified, the destinations of vehicles CR[1] to CR[n] are assumed to coincide with each other. In this case, the destination of the platoon is the same as the destination of vehicles CR[1] to CR[n]. However, the destinations of vehicles CR[1] to CR[n] may include two or more different destinations. In this case, a vehicle CR with a destination set different from the destination of the platoon (destination of the reference vehicle) will leave the platoon while traveling from the current location of the platoon to the destination of the platoon (destination of the reference vehicle). The planned travel route of the platoon represents the planned route along which the platoon will travel when heading towards the destination of the platoon.

The main control unit 10 executes driving processing. Driving processing is executed for each in-vehicle device 1. The driving processing is driving control for driving the host vehicle.

The driving process in the lead vehicle is the lead driving process. In the lead driving process, the actuator unit 80 of the vehicle is controlled so that the vehicle (i.e., the lead vehicle) drives along the planned driving route. In this case, for example, the actuator unit 80 may be controlled based on the driving information of the vehicle so that the driving speed of the vehicle is kept constant or within a predetermined speed range. If the platoon drives on an ordinary road or an expressway, the actuator unit 80 may be controlled in the driving process in the lead vehicle so that the driving speed of the vehicle is kept within a predetermined speed range that is below the legal speed limit for each road.

The driving process of the following vehicle is a follow-up driving process. In the follow-up driving process, the inter-vehicle distance between the host vehicle and the vehicle immediately preceding the host vehicle is detected based on information about the host vehicle's surroundings (particularly distance measurement information). Then, in the follow-up driving process, the actuator unit 80 of the host vehicle is controlled while referencing the host vehicle's driving information and surrounding information so that the host vehicle follows the immediately preceding vehicle while maintaining the detected inter-vehicle distance within a predetermined distance range. In this control, the driving information of the lead vehicle or the driving information of the vehicle immediately preceding the host vehicle may be referenced. With respect to the host vehicle, the immediately preceding vehicle refers to the vehicle traveling immediately before the host vehicle among the multiple vehicles CR forming the platoon.

The driving process in each vehicle CR causes the n vehicles CR to form a convoy and proceed towards the convoy's destination. During the driving process by each main control unit 10, the actuator unit 80 of each vehicle CR is controlled based on the results of the obstacle monitoring process described below to prevent each vehicle CR from colliding with an obstacle.

The main control unit 10 executes obstacle monitoring processing. One main control unit 10 among the in-vehicle devices 1[1] to 1[n] may perform the obstacle monitoring processing, or two or more main control units 10 among the in-vehicle devices 1[1] to 1[n] may cooperate to perform the obstacle monitoring processing. In the obstacle monitoring processing, obstacles around the platoon are monitored based on the surrounding information output from the surrounding information detection unit 30 of each vehicle CR. Monitoring obstacles around the platoon is equivalent to monitoring obstacles around each vehicle CR that forms the platoon. Obstacles are three-dimensional objects separate from the vehicles CR. In obstacle monitoring, the presence or absence of an obstacle is detected, and if an obstacle is detected, the positional relationship between the platoon and the obstacle is detected.

The main control unit 10 executes the formation control process. One main control unit 10 among the on-board devices 1[1] to 1[n] may execute the formation control process, or two or more main control units 10 among the on-board devices 1[1] to 1[n] may cooperate to execute the formation control process. Here, it is assumed that the formation control process is executed by the main control unit 10 of the on-board device 1 mounted on the reference vehicle. The formation control process controls the formation state of the platoon. The formation state of the platoon is determined by the number of vehicles in the platoon and the running order of vehicles CR[1] to CR[n] in the platoon. The number of vehicles in the platoon is the number of vehicles CR that form the platoon, and therefore has a value of n. When the platoon is formed, the main control unit 10 of the reference vehicle determines which vehicle CR will run in what order in the platoon during the formation control process, and transmits the determination to the on-board devices 1 of the non-reference vehicles. The on-board device 1 of each non-reference vehicle controls the actuator unit 80 according to the transmitted content. The formation control process may change the formation state of the platoon. That is, for example, the formation control process may increase or decrease the number of vehicles in the platoon. Also, for example, the formation control process may change the running order of vehicles CR[1] to CR[n] in the platoon.

The main control unit 10 executes an event detection process. This process is executed for each in-vehicle device 1. The event detection process for each in-vehicle device 1 detects whether m types of events have occurred. An event is an unusual occurrence that can occur during platooning (for example, a change in the platoon's running order or the detection of abnormal G-sensor information that corresponds to an accident). The content and detection method of each event will be described in detail later. Note that, unless otherwise specified, the event referred to in the following description refers to any of the m types of events. Event conditions (predetermined event conditions) are defined for each type of event. The m types of events are referred to as the first through mth events. The first through mth events may also be read as the first through mth types of events. m is an integer greater than or equal to 2. However, "m = 1" is also acceptable. The event detection process determines whether each event condition is met, and when the jth event condition is met, the jth event is detected or determined to have occurred. j represents any natural number less than or equal to m.

The main control unit 10 executes the event occurrence notification process. The event occurrence notification process is executed for each in-vehicle device 1. When the occurrence of an event is detected during the event detection process of the host vehicle, the main control unit 10 of the host vehicle executes the event occurrence notification process and notifies the in-vehicle devices 1 of other vehicles of the event occurrence notification process. If there are multiple other vehicles, the event occurrence notification is sent to each of the other vehicles. The event occurrence notification is realized by transmitting an event occurrence notification signal to the in-vehicle devices 1 of the other vehicles via vehicle-to-vehicle communication.

The main control unit 10 executes recording control processing. Recording control processing is executed for each in-vehicle device 1. Recording control processing is processing for recording camera image information, etc., to the internal memory 12 or recording medium 70. As event-related recording control processing, the main control unit 10 can execute event recording processing. In event recording processing, an event recording period is set when the occurrence of any of the first to mth events is detected. The event recording processing also includes processing for recording camera image information during the event recording period to the recording medium 70.

The main control unit 10 in the host vehicle performs event recording processing when the occurrence of any event is detected during the event detection processing of the in-vehicle device 1 of the host vehicle. In addition, when the occurrence of any event is detected during the event detection processing of the in-vehicle device 1 of another vehicle, the main control unit 10 in the host vehicle performs event recording processing upon receiving an event occurrence notification (i.e., upon receiving an event occurrence notification signal).

As shown in FIG. 8, functional blocks 111-119 may be provided in the main control unit 10. Functional blocks 111-119 may be realized by executing the platooning program 62 in the calculation processing unit 11 of the main control unit 10. However, some of functional blocks 111-119 may be realized only in the main control units 10 of some of the on-board devices 1[1]-1[n].

The functional block 111 is a host vehicle information acquisition unit that performs host vehicle information acquisition processing.
The functional block 112 is an other vehicle information acquisition unit that performs other vehicle information acquisition processing.
The functional block 113 is a route setting unit that performs route setting processing.
The function block 114 is a driving processing unit that performs driving processing.
The function block 115 is an obstacle monitoring unit that performs obstacle monitoring processing.
The functional block 116 is a composition control unit that performs composition control processing.
The function block 117 is an event detection unit that performs event detection processing.
The function block 118 is an event occurrence notification unit that performs an event occurrence notification process.
The function block 119 is a recording control unit that performs recording control processing.

In addition, during the host vehicle information acquisition process, camera image information is acquired while information about the host vehicle's surroundings is acquired (see Figures 4 and 6), so it can be said that the host vehicle information acquisition unit 111 has the function of an image information acquisition unit.

The flow of operation of the system SYS related to the occurrence of an event will be explained with reference to Figure 9. Also refer to Figure 10, which explains the event recording period, and Figure 11, which shows the event occurrence notification, as appropriate.

First, in step S1, the occurrence of a jth event, which is an arbitrary type of event, is detected in the in-vehicle device 1[i] of any one of the vehicles CR[1] to CR[n]. That is, it is determined that the jth event condition is met in the in-vehicle device 1[i]. The time at which the occurrence of the jth event is detected by the in-vehicle device 1[i] (i.e., the time at which the occurrence of the jth event is detected in the in-vehicle device 1[i]) is referred to as time _tEV (see FIG. 10). Time _tEV corresponds to the time at which it is determined that the jth event condition is met.

In step S2 following step S1, an event notification process is executed in the in-vehicle device 1[i]. That is, as shown in FIG. 11 , an event occurrence notification signal NS is transmitted from the in-vehicle device 1[i] to each of the in-vehicle devices 1 other than the in-vehicle device 1[i] among the in-vehicle devices 1[1] to 1[n]. Each of the in-vehicle devices 1 other than the in-vehicle device 1[i] receives the event occurrence notification signal NS. Then, in step S3, an event recording process is executed in each of the in-vehicle devices 1[1] to 1[n]. The signal NS includes information representing the time t _EV . Note that the time t _EV may be information representing a date and time (i.e., information specifying the date and time when the occurrence of the jth event was detected).

Referring to FIG. 10 , the event recording period set in response to the detection of the occurrence of the jth event (in other words, the event recording period set in response to the establishment of the jth event condition) will be described. The start time of the event recording period is a predetermined time T _PRE (e.g., 12 seconds) before time t _EV , and the end time of the event recording period is a predetermined time T _POST (e.g., 8 seconds) after time t _EV . The times T _PRE and T _POST may be predetermined times, and may or may not coincide. Either of the times T _PRE and T _POST may be zero. During the operation period of each in-vehicle device 1, a period other than the event recording period is referred to as a non-event period.

Referring to Figures 12(a) and (b), the information recorded on the recording medium 70 during the event recording process in step S3 will be described. In step S3, in-vehicle device 1[i] performs event recording process in response to detecting the occurrence of the jth event, and each in-vehicle device 1 among in-vehicle devices 1[1] to 1[n] other than in-vehicle device 1[i] performs event recording process in response to receiving an event occurrence notification signal NS. Note that hereinafter, the jth event and jth event condition may be simply referred to as the event and event condition.

In the event recording process of step S3, each of the in-vehicle devices 1[1] to 1[n] associates camera image information and additional information from the event recording period with each other and records them on the recording medium 70. If multiple cameras are installed on the vehicle CR[i] as cameras 31, the camera image information from each camera may be recorded on the recording medium 70 of the in-vehicle device 1[i]. Therefore, for example, in the example of Figure 5, in the event recording process, the camera image information from each of the cameras 31F, 31B, 31R, and 31L installed on the vehicle CR[i] may be recorded on the recording medium 70 of the in-vehicle device 1[i].

The additional information includes information AD1 to AD8. However, the additional information may include only one or more pieces of information AD1 to AD8.

Information AD1 is occurrence event information that indicates the details of the event whose occurrence has been detected. If the event whose occurrence has been detected is a first event, information indicating the details of the first event is set in information AD1, and if the event whose occurrence has been detected is a second event, information indicating the details of the second event is set in information AD1. Information indicating which event has been detected is included in the event occurrence notification signal NS. Therefore, information AD1 can be identified by each in-vehicle device 1.

Information AD2 represents the identification ID (identification information) of the vehicle CR in which the in-vehicle device 1 that detected the event occurrence is installed. Each vehicle CR is assigned a unique identification ID. Each in-vehicle device 1 recognizes its own vehicle's identification ID in advance. In-vehicle device 1[i] includes its own vehicle's identification ID in the event occurrence notification signal NS that it sends to other in-vehicle devices 1. Therefore, information AD2 can be identified by each in-vehicle device 1.

Information AD3 indicates the date and time when the occurrence of the event was detected, and therefore indicates time _tEV (see FIG. 10). As described above, time _tEV may be information indicating date and time. Time _tEV is included in the event occurrence notification signal NS. Therefore, information AD3 can be identified by each in-vehicle device 1. Information AD4 indicates whether the host vehicle was traveling in a convoy at time _tEV . Information AD5 indicates the identification ID (identification information) of the convoy formed including the host vehicle. When the host vehicle is incorporated into the convoy, the identification ID of the convoy is set in the in-vehicle device 1 of the reference vehicle, and the set content is notified to each of the other in-vehicle devices 1.

Information AD6 is driving order information that indicates the driving order of the host vehicle at time t _EV . The driving order of the host vehicle is the driving order of the host vehicle in the platoon and indicates the position of the host vehicle from the front in the platoon. For example, consider a first case in which "n = 5" and _vehicles CR[1], CR[2], CR[3], CR[4], and CR[5] are lined up in this order from front to rear and driving in a platoon at time t EV. In this first case, the driving order of vehicle CR[i] is the ith, and information AD6 in the event recording process of on-board device 1[i] indicates that the driving order of the host vehicle (i.e., vehicle CR[i]) is the ith. When the host vehicle is incorporated into the platoon, the driving order of the host vehicle is determined by the reference vehicle, and the determined order is notified to the host vehicle by the reference vehicle (if the reference vehicle itself is the host vehicle, this notification is not necessary).

Information AD7 is first inter-vehicle distance information representing the inter-vehicle distance between the host vehicle and the immediately preceding vehicle at time _tEV . As described above, with respect to the host vehicle, the immediately preceding vehicle refers to the vehicle traveling immediately before the host vehicle among the multiple vehicles CR forming the platoon. Information AD8 is second inter-vehicle distance information representing the inter-vehicle distance between the host vehicle and the immediately following vehicle at time _tEV . With respect to the host vehicle, the immediately following vehicle refers to the vehicle traveling immediately after the host vehicle among the multiple vehicles CR forming the platoon. In the first case described above, if the host vehicle is vehicle CR[3], vehicle CR[2] corresponds to the immediately preceding vehicle and vehicle CR[4] corresponds to the immediately following vehicle. Note that when the host vehicle is the leading vehicle, there is no immediately preceding vehicle, and therefore information AD7 is not included in the additional information for the leading vehicle. Similarly, when the vehicle is the last vehicle, there is no vehicle immediately following it, and therefore information AD8 is not included in the additional information for the last vehicle. In each in-vehicle device 1, the recording control unit 119 can generate information AD7 and AD8 using the surrounding information (particularly distance measurement information) output from the surrounding information detection unit 30.

In each in-vehicle device 1, the recording control unit 119 operates in either event recording mode or continuous recording mode. The recording control unit 119 may be configured to be able to switch between operating in event recording mode or continuous recording mode, or the recording control unit 119 may be configured to operate in only one of the event recording mode or continuous recording mode.

In event recording mode, the operation of recording image information to the recording medium 70 is performed only when an event recording operation is performed. That is, in event recording mode, camera image information during non-event periods is not recorded to the recording medium 70 (recording of camera image information to the recording medium 70 is stopped during non-event periods). In event recording mode, camera image information during event recording periods is recorded to the recording medium 70 along with additional information.

When recording camera image information on the recording medium 70, the internal memory 12 is used as appropriate. A ring buffer is formed in the internal memory 12 to temporarily record camera image information for a predetermined period of time. Information AD6 to AD8 (see FIG. 12(b)) may be added to the camera image information recorded in the ring buffer. When new camera image information to be recorded is input to the main control unit 10 after a certain period of time of camera image information has been recorded in the ring buffer, the latest camera image information is overwritten and recorded over the oldest recorded camera image information. Therefore, the latest camera image information for a certain period of time is always held in the ring buffer. By using this ring buffer, camera image information generated by the camera 31 between a certain time (>T _PRE ) before time t _EV and time t _EV can be read from the ring buffer at or after time _{t EV .}

The recording control unit 119 in the continuous recording mode records camera image information of the vehicle as unprotected data on the recording medium 70 while the in-vehicle device 1 is operating, regardless of the results of the event detection process, i.e., regardless of whether an event has occurred. Information AD6 to AD8 (see Figure 12(b)) may be added to the unprotected data. The recording medium 70 has a recording area large enough to store a maximum of a predetermined amount of unprotected data. In the continuous recording mode, when a predetermined amount of unprotected data has been recorded on the recording medium 70 and new unprotected data is generated, the newest unprotected data is overwritten on the previous unprotected data on the recording medium 70. Overwriting and recording first data over second data means erasing the second data from the recording medium 70 and recording the first data on the recording medium 70 instead. The previous unprotected data to be overwritten is the unprotected data acquired and recorded at the earliest time among all unprotected data recorded on the recording medium 70. In this way, in continuous recording mode, the camera image information of the vehicle is set as unprotected data, and is continuously recorded on the recording medium 70 in a manner that allows overwriting of the unprotected data.

The recording control unit 119 in continuous recording mode sets the camera image information during the event recording period as protected data and records the protected data on the recording medium 70 in a manner that prohibits overwriting. Additional information corresponding to the camera image information during the event recording period is also included in the protected data. Once protected data is recorded on the recording medium 70, it will not be erased from the recording medium 70 or overwritten by other data unless a specified release operation is performed. Hereinafter, recording certain data (information) as protected data on the recording medium 70 may be referred to as protected recording or protected recording.

As can be understood from the above explanation, unprotected data means data that is permitted to be overwritten, while protected data means data that is prohibited from being overwritten. Therefore, recording certain data as unprotected data is synonymous with recording that data in a manner that allows overwriting, and recording certain data as protected data is synonymous with recording that data in a manner that prohibits overwriting. Separate recording areas for recording unprotected data and recording areas for recording protected data may be set up on the recording medium 70, or data may be classified as unprotected or protected by managing flags or the like.

By the way, the first to mth events include events (specific events) unique to platooning.

This makes it possible to record events related to platooning (specific events) when they occur, something that was not possible with existing drive recorders. In other words, it is possible to achieve effective event recording for platooning.

Events unique to platooning (specific events) correspond or have the potential to correspond to dangerous situations unique to platooning. Therefore, by using the information recorded on the recording medium 70 in the event recording process according to this embodiment, it is possible to easily create a learning dataset that is effective for machine learning in AI (artificial intelligence) that determines dangerous situations during platooning.

Events unique to platooning (specific events) include a formation change event in which the formation of vehicles CR[1] to CR[n] is changed, and also, or instead of, a platoon cut-in event in which a general vehicle cuts into the platoon. A general vehicle is a vehicle that is different from vehicles CR[1] to CR[n]. In other words, a general vehicle is a vehicle that does not belong to the group of vehicles (CR[1] to CR[n]) that form the platoon.

Formation status change events include a vehicle count increase event, which increases the number of vehicles CR forming the platoon; a vehicle count decrease event, which decreases the number of vehicles CR forming the platoon; and a sequence change event, which changes the running order of vehicles CR[1] to CR[n]. The vehicle count increase event, vehicle count decrease event, and sequence change event are three of the first to mth events. However, any one or two of the vehicle count increase event, vehicle count decrease event, and sequence change event do not have to be included in the first to mth events.

Compared to situations where the platoon is traveling stably without changing its formation, situations where the platoon's formation changes make the driving control of each vehicle more complex and more likely to become dangerous. Furthermore, when a regular vehicle cuts in on the platoon, it becomes difficult to maintain platoon driving. By treating these situations as events and recording them, effective event recording of platoon driving can be achieved.

Note that a platoon cutting-in event is an example of an event that makes it difficult to maintain platoon driving. Events that make it difficult to maintain platoon driving, other than platoon cutting-in events, may be included in the first through mth events.

The following describes specific operational examples, application techniques, modified techniques, etc. related to the system SYS in multiple embodiments. The matters described above in this embodiment apply to each of the following embodiments unless otherwise stated and unless there is a contradiction. If there are any matters in each embodiment that contradict the matters described above, the descriptions in each embodiment may take precedence. Furthermore, unless there is a contradiction, the matters described in any of the multiple embodiments described below can also be applied to any of the other embodiments (i.e., any two or more of the multiple embodiments can also be combined).

<<Example EX1>>
Example EX1 will be described. In Example EX1, the above-mentioned vehicle number increase event corresponds to the j-th event in step S1 (see FIG. 9 ). A known method can be used to add a new vehicle to a group of vehicles traveling in a convoy, and a specific example will be given below.

Refer to Figure 13. Assuming the initial state ST1_a is "n=3" and vehicles CR[1], CR[2], and CR[3] are lined up in this order from front to rear and traveling in a convoy. In this state, vehicle CR[1] is the reference vehicle. The convoy described in this embodiment refers to a convoy formed including vehicles CR[1] to CR[3].

Starting from the initial state ST1_a, vehicle CR' equipped with on-board device 1 approaches a platoon consisting of vehicles CR[1] to CR[3]. The on-board device 1 of vehicle CR' transmits a platoon incorporation request signal to its surroundings. The platoon incorporation request signal requests that vehicle CR' be incorporated into the platoon, and includes destination information indicating the destination of vehicle CR' and the vehicle's ID. When the platoon incorporation request signal is received by on-board device 1[1] of reference vehicle CR[1], the formation control unit 116 of on-board device 1[1] compares the destination indicated in the destination information in the platoon incorporation request signal with the destination of the platoon to determine whether or not to incorporate vehicle CR' into the platoon. This determination may also be made based on the planned route of the platoon. If the compared destinations match or are similar, the formation control unit 116 of on-board device 1[1] allows vehicle CR' to be incorporated into the platoon. Even if the compared destinations do not match, vehicle CR' may be permitted to be incorporated into the platoon depending on the planned travel route of the platoon and vehicle CR's destination.

When permitting vehicle CR' to be incorporated into the platoon, the formation control unit 116 of on-board device 1 [1] transmits a platoon incorporation permission signal to on-board device 1 of vehicle CR', permitting vehicle CR' to be incorporated into the platoon. The platoon incorporation permission signal includes the identification ID of the platoon, as well as a signal indicating that vehicle CR' should travel behind vehicle CR [3], such as indicating that vehicle CR' is fourth in the platoon's running order. Upon receiving the platoon incorporation permission signal, on-board device 1 of vehicle CR' controls the driving of vehicle CR' so that vehicle CR' follows vehicle CR [3]. This results in state ST1_b, in which vehicle CR' has been incorporated into the platoon as vehicle CR [4]. Furthermore, when transmitting the platoon incorporation permission signal, on-board device 1 [1] notifies on-board devices 1 [2] and 1 [3] that vehicle CR' will be incorporated into the platoon as vehicle CR [4].

In this embodiment, the event detection unit 117 in the in-vehicle device 1[1] of the reference vehicle CR[1] detects the occurrence of a vehicle number increase event. The transmission of the convoy incorporation permission signal may be considered to correspond to the occurrence of a vehicle number increase event. In this case, the detection time _tEV of the occurrence of the vehicle number increase event may be the transmission time of the convoy incorporation permission signal. After the transmission of the convoy incorporation permission signal, vehicle CR' follows vehicle CR[3] behind, and each in-vehicle device 1 may continue the event recording period until the following traveling stabilizes. In this case, the recording control unit 119 of the reference vehicle CR may set the end time of the event recording period.

As described above, under the control of the formation control unit 116 of the on-board device 1[1] installed on the reference vehicle CR[1], a vehicle CR' that was not previously part of the platoon is newly incorporated into the platoon, thereby increasing the number of vehicles CR forming the platoon. In other words, in the on-board device 1[1], the formation control unit 116 has the function of controlling the number of vehicles CR forming the platoon, and the event detection unit 117 detects whether a vehicle number increase event has occurred based on the control content of the formation control unit 116. This makes it possible to properly detect whether a vehicle number increase event has occurred.

Here, it is assumed that each vehicle CR is maintained in a running state (a state in which the speed is greater than zero) during the process from the initial state ST1_a to state ST1_b. However, this process may include periods in which each vehicle CR is stopped. For example, after vehicles CR[1] to CR[3] that were running in the initial state ST1_a stop in a parking area or the like, when vehicles CR[1] to CR[3] restart, vehicle CR' may be incorporated into the platoon as the rearmost vehicle CR[4]. In this case, the restart of each vehicle CR in a formation with an increased number of vehicles CR forming the platoon after each vehicle CR stops can be considered to correspond to a number increase event. In this case, for example, the departure time of the reference vehicle CR[1] (the time when the speed of the reference vehicle CR[1] transitions from zero to a state greater than zero) may be considered to be the detection time _tEV of the occurrence of the number increase event.

In the example of Figure 13, vehicle CR' is incorporated into the platoon as the rearmost vehicle, but vehicle CR' may also be incorporated into the platoon as an intermediate vehicle.

<<Example EX2>>
In the embodiment EX2, the above-mentioned event of decreasing the number of vehicles corresponds to the j-th event (see FIG. 9) in step S1.

Refer to Figure 14. Assuming that the initial state ST2_a is "n=4" and that vehicles CR[1], CR[2], CR[3], and CR[4] are lined up in this order from front to rear and traveling in a convoy. In this state, vehicle CR[1] is the reference vehicle. In this embodiment, the convoy refers to a convoy formed including vehicles CR[1] to CR[4] or a convoy formed including vehicles CR[1] to CR[3].

Starting from the initial state ST2_a, the on-board device 1 [4] of vehicle CR [4] transmits a platoon departure request signal to the on-board device 1 [1] of the reference vehicle CR [1]. The platoon departure request signal here is a signal requesting that the vehicle leave the platoon and includes the identification ID of vehicle CR [4]. When the platoon departure request signal is received by the on-board device 1 [1] of the reference vehicle CR [1], the formation control unit 116 of the on-board device 1 [1] generally transmits a platoon departure permission signal to the on-board device 1 [4] indicating that vehicle CR [4] is permitted to leave the platoon. However, if there are special circumstances that prohibit the departure, the formation control unit 116 of the on-board device 1 [1] may transmit a platoon departure prohibition signal to the on-board device 1 [4] indicating that the departure is not permitted, instead of the platoon departure permission signal. In addition, the formation control unit 116 of the in-vehicle device 1[1] can also send a platoon departure instruction signal to the in-vehicle device 1[4] as necessary, regardless of whether a platoon departure request signal has been received. The platoon departure instruction signal here is a signal that instructs vehicle CR[4] to leave the platoon.

When in-vehicle device 1 [4] receives the platoon departure permission signal or platoon departure instruction signal, it stops the following process, which causes vehicle CR [4] to follow vehicle CR [3]. Then, under the control of in-vehicle device 1 [4], vehicle CR [4] leaves the platoon as a vehicle CR' that does not form part of the platoon. State ST2_b represents the state after this departure is complete. When in-vehicle device 1 [1] transmits the platoon departure permission signal or the platoon departure instruction signal, it notifies in-vehicle devices 1 [2] and 1 [3] that vehicle CR [4] will leave the platoon.

In this embodiment, the event detection unit 117 in the on-board device 1[1] of the reference vehicle CR[1] detects the occurrence of a vehicle number reduction event. The transmission of a platoon departure permission signal or a platoon departure instruction signal may be considered to correspond to the occurrence of a vehicle number reduction event. In this case, the detection time _tEV of the occurrence of the vehicle number reduction event may be the transmission time of the platoon departure permission signal or the platoon departure instruction signal.

As described above, under the control of the formation control unit 116 of the on-board device 1[1] installed on the reference vehicle CR[1], a vehicle CR that had been forming a platoon leaves the platoon, thereby reducing the number of vehicles CR forming the platoon. In other words, in the on-board device 1[1], the formation control unit 116 has the function of controlling the number of vehicles CR that form the platoon, and the event detection unit 117 detects whether a vehicle count reduction event has occurred based on the control content of the formation control unit 116. This makes it possible to properly detect whether a vehicle count reduction event has occurred.

Here, it is assumed that each vehicle CR is maintained in a running state (a state in which the speed is greater than zero) during the process from the initial state ST2_a to state ST2_b. However, this process may include a period in which each vehicle CR stops. For example, after vehicles CR[1] to CR[4] that were running in the initial state ST2_a stop in a parking area or the like, when vehicles CR[1] to CR[3] restart, the vehicle that was vehicle CR[4] may leave the platoon as vehicle C'' (i.e., for example, when vehicle CR[3] restarts, the vehicle that was vehicle CR[4] may not follow vehicle CR[3]). In this case, the restart of each vehicle CR in a formation with a reduced number of vehicles CR forming the platoon after each vehicle CR stops can be considered to correspond to a vehicle number reduction event. In this case, for example, the departure time of the reference vehicle CR[1] (the time when the speed of the reference vehicle CR[1] transitions from zero to a state greater than zero) may be regarded as the detection time t _EV of the occurrence of the vehicle number reduction event.

Note that in the example shown in Figure 14, the rearmost vehicle in the convoy leaves the convoy, but it is also possible for a middle vehicle in the convoy to leave the convoy.

<<Example EX3>>
An example EX3 will be described below. In the example EX3, the above-mentioned order change event corresponds to the j-th event in step S1 (see FIG. 9).

Refer to Figure 15. Assume that the initial state ST3_a is "n=4" and vehicles CR[1] to CR[4] are traveling in a convoy in the first traveling order. In the first traveling order, vehicles CR[1], CR[2], CR[3], and CR[4] are lined up in this order from front to rear. Vehicle CR[1] is the reference vehicle. The convoy described in this embodiment refers to a convoy formed including vehicles CR[1] to CR[4].

Starting from the initial state ST3_a, the formation control unit 116 of the on-board device 1[1] decides to change the traveling order of the platoon from the first traveling order to the second traveling order. In the second traveling order, vehicles CR[1], CR[4], CR[3], and CR[2] are lined up in this order from front to rear. In other words, by changing from the first traveling order to the second traveling order, the rearmost vehicle changes from vehicle CR[4] to vehicle CR[2]. For example, if some abnormality occurs in the distance measurement sensor 32 installed in vehicle CR[4], making it difficult to monitor obstacles behind vehicle CR[4], the formation control unit 116 of the on-board device 1[1] decides to change to the second traveling order.

Based on the above decision, the formation control unit 116 of on-board device 1[1] transmits a sequence change instruction signal to on-board devices 1[2]-1[4], instructing them to change the platoon's running order from the first running order to the second running order. In each of on-board devices 1[2]-1[4] that receives the sequence change instruction signal, the driving processing unit 114 controls the actuator unit 80 while referring to peripheral information to achieve the second running order. That is, the running order of each vehicle is rearranged so that vehicle CR[4] follows vehicle CR[1], vehicle CR[3] follows vehicle CR[4], and vehicle CR[2] follows vehicle CR[3]. This transitions to state ST3_b, in which vehicles CR[1]-CR[4] are running in platoon in the second running order. Note that the process of changing the running order is not shown in Figure 15 (only the state of the platoon before and after the change in running order is shown). Known methods can be used as specific driving control methods for changing the driving order in a platoon.

In this embodiment, the event detection unit 117 in the in-vehicle device 1[1] of the reference vehicle CR[1] detects the occurrence of an order change event. The transmission of the order change instruction signal may be considered to correspond to the occurrence of an order change event. In this case, the detection time _tEV of the occurrence of the order change event may be the transmission time of the order change instruction signal. After time _tEV , each in-vehicle device 1 may continue the event recording period until it is determined that the driving of vehicles CR[1] to CR[4] according to the second driving order is stable. In this case, the recording control unit 119 of the reference vehicle CR may set the end time of the event recording period.

As described above, the running order of the group of vehicles forming the platoon (here, vehicles CR[1] to CR[4]) is changed under the control of the formation control unit 116 of the onboard device 1[1] installed on the reference vehicle CR[1]. In other words, in the onboard device 1[1], the formation control unit 116 has the function of controlling the running order of the group of vehicles forming the platoon, and the event detection unit 117 detects whether or not an order change event has occurred based on the control content of the formation control unit 116. This allows for accurate detection of whether or not an order change event has occurred.

Here, it is assumed that each vehicle CR is maintained in a traveling state (a state in which the speed is greater than zero) during the process from the initial state ST3_a to state ST3_b. However, this process may include a period in which each vehicle CR stops. For example, after the vehicles CR[1] to CR[4] traveling in the first traveling order stop in a parking area or the like, the vehicles CR[1] to CR[4] may restart in the second traveling order. In this case, the restart of each vehicle CR in the second traveling order after each vehicle CR forming the platoon stops can be considered to correspond to an order change event. In this case, for example, the departure time of the reference vehicle CR[1] (the time when the speed of the reference vehicle CR[1] transitions from zero to a state greater than zero) may be considered to be the detection time _tEV of the occurrence of the order change event.

<<Example EX4>>
An example EX4 will be described below. In the example EX4, the above-mentioned formation interruption event corresponds to the j-th event in step S1 (see FIG. 9).

Refer to Figure 16. Assuming the initial state ST4_a is "n=3" and vehicles CR[1], CR[2], and CR[3] are lined up in this order from front to rear and traveling in a convoy. In this state, vehicle CR[1] is the reference vehicle. In this embodiment, the convoy refers to a convoy formed including vehicles CR[1] to CR[3].

In the initial state ST4_a, no ordinary vehicle has cut in the platoon. That is, in the initial state ST4_a, there are no ordinary vehicles between vehicles CR[1] and CR[2], and there are no ordinary vehicles between vehicles CR[2] and CR[3]. Starting from the initial state ST4_a, ordinary vehicle CC approaches the platoon, resulting in state ST4_b. In state ST4_b, part of the body of ordinary vehicle CC is present between vehicles CR[2] and CR[3]. In the subsequent state ST4_c, the entire body of ordinary vehicle CC is present between vehicles CR[2] and CR[3], and vehicles CR[1] to CR[3] travel with ordinary vehicle CC sandwiched between vehicles CR[2] and CR[3]. Furthermore, as ordinary vehicle CC leaves the space between vehicles CR[2] and CR[3], state ST4_d is reached. In state ST4_d, there is no general vehicle CC between vehicles CR[2] and CR[3].

Maintaining convoy travel becomes difficult when a general vehicle CC cuts in on the convoy, but here we assume that the time the general vehicle CC cuts in on the convoy is sufficiently short, and that convoy travel is maintained from the initial state ST4_a to state ST4_d, and even after state ST4_d.

In the example of Figure 16, the event detection unit 117 in the in-vehicle device 1[2] or 1[3] detects the occurrence of a platoon interruption event based on the surrounding information acquired by vehicle CR[2] or CR[3]. Below, it is assumed that the event detection unit 117 in the in-vehicle device 1[3] detects the occurrence of a platoon interruption event based on the surrounding information acquired by vehicle CR[3].

For convenience, a state in which all or part of the body of a general vehicle CC is present in the space between vehicles CR[2] and CR[3] will be referred to as an interruption state, and a state in which this is not the case will be referred to as a non-interruption state. In the in-vehicle device 1[3], the event detection unit 117 can determine whether the current state is an interruption state or a non-interruption state based on the surrounding information acquired from the surrounding state detection unit 30.

When the in-vehicle device 1 [3] transitions from a non-interrupt state to an interrupt state, the event detection unit 117 determines that the interruption of the general vehicle CC has begun (for convenience, this determination is referred to as an interruption start determination). Thereafter, when the in-vehicle device 1 [3] transitions from an interruption state to a non-interruption state, the event detection unit 117 determines that the interruption of the general vehicle CC has ended (for convenience, this determination is referred to as an interruption end determination).

The making of a cut-in start determination may correspond to the detection of the occurrence of a formation cut-in event. In this case, the detection time t _EV of the occurrence of the formation cut-in event may be the time when the cut-in start determination is made. Thereafter, the event recording period may be continued at least until the cut-in end determination is made. Alternatively, the making of a cut-in end determination may correspond to the detection of the occurrence of a formation cut-in event. In this case, the detection time t _EV of the occurrence of the formation cut-in event may be the time when the cut-in end determination is made.

In practice, for a formation cut-in event, the period from the following first time to second time may be set as the event recording period. The first time is a predetermined time T _PRE before the time when the cut-in start determination is made. The second time is a predetermined time T _POST after the time when the cut-in end determination is made. In this case, the detection time t _EV of the formation cut-in event may be understood as the time when the cut-in start determination is made. Alternatively, the detection time t _EV of the formation cut-in event may be understood as a concept having a time span from the time when the cut-in start determination is made to the time when the cut-in end determination is made.

In this way, whether or not a platoon interruption event has occurred is detected using a group of sensors installed on the vehicles forming the platoon to observe the area around the platoon. The group of sensors includes a camera 31 and a distance measurement sensor 32 installed on each vehicle CR forming the platoon. In the example of Figure 16, the camera 31 and distance measurement sensor 32 installed on vehicle CR[3] in particular function effectively to detect the occurrence of a platoon interruption event. By using the above group of sensors, which are also used to realize platoon driving, a platoon interruption event can be easily detected.

<<Example EX5>>
An example EX5 will be described. The first to m-th events may include events that are not particularly related to platooning, in addition to events that are specific to platooning (specific events).

For example, a G event may be included in the first to mth events. In the in-vehicle device 1[i], the event detection unit 117 calculates the absolute value of the acceleration acting on the host vehicle CR[i] as a G value based on G sensor information from the host vehicle CR[i], and determines that a G event has occurred in the host vehicle CR[i] when a G value equal to or greater than a predetermined threshold is observed. In the host vehicle CR[i], a G event mainly occurs when, for example, some kind of three-dimensional object (any other vehicle or obstacle, etc.) collides with the host vehicle CR[i]. For this reason, a G event may be considered a type of object collision event.

For example, a sudden braking event may be included in the first to mth events. A sudden braking event is an event in which the brakes are suddenly applied. In the in-vehicle device 1[i], the event detection unit 117 can detect whether a sudden braking event has occurred in the host vehicle CR[i] based on the amount of operation of the brakes on the host vehicle CR[i].

For example, an abrupt steering event may be included in the first to mth events. An abrupt steering event is an event in which the steering angle of the vehicle CR changes suddenly. In the in-vehicle device 1[i], the event detection unit 117 can detect whether an abrupt steering event has occurred in the host vehicle CR[i] based on the amount of change in the steering angle of the host vehicle CR[i].

For example, a sudden acceleration event may be included in the first to mth events. In the in-vehicle device 1[i], the event detection unit 117 can calculate the absolute value of the change in the increasing direction of the speed of the vehicle CR based on the vehicle speed information of the vehicle CR[i]. In the in-vehicle device 1[i], the event detection unit 117 determines that a sudden acceleration event has occurred in the vehicle CR[i] when the absolute value of the change is equal to or greater than a predetermined upper acceleration limit.

For example, a sudden deceleration event may be included in the first to mth events. In the in-vehicle device 1[i], the event detection unit 117 can calculate the absolute value of the change in the speed of the vehicle CR in the direction of a decrease, based on the vehicle speed information of the vehicle CR[i]. In the in-vehicle device 1[i], the event detection unit 117 determines that a sudden deceleration event has occurred in the vehicle CR[i] when the absolute value of the change is equal to or greater than a predetermined upper deceleration limit.

For example, a start event and a stop event may be included in the first to mth events. A start event is an event in which the host vehicle CR starts (an event in which the speed of the host vehicle CR transitions from a state where it is zero to a state where it is greater than zero). A stop event is an event in which the host vehicle CR stops (an event in which the speed of the host vehicle CR transitions from a state where it is greater than zero to a state where it is zero). In the in-vehicle device 1[i], the event detection unit 117 can detect whether a start event or a stop event has occurred based on the vehicle speed information of the host vehicle CR[i].

When platooning, the risk of rear-end collisions and other incidents can be higher when starting or stopping than when driving steadily. Therefore, it is a good idea to include starting and stopping events in the first through mth events. Note that starting and stopping events may be detected only by the event detection unit 117 of the reference vehicle CR. This is because each non-reference vehicle also starts or stops in conjunction with the starting or stopping of the reference vehicle.

In addition, the event detection unit 117 may detect whether or not various events (red light ignoring events, swaying events) have occurred.

The event detection unit 117 in the in-vehicle device 1[ _iA ] may be able to detect whether an event has occurred in the vehicle CR[ _iB ]. Here, _iA and _iB are different natural numbers equal to or less than n. For example, in state ST1_a of FIG. 13 , the event detection unit 117 in the in-vehicle device 1[3] may refer to the surrounding information acquired by the surrounding information detection unit 30 of the host vehicle CR[3] to determine whether the vehicle CR[2], the vehicle directly ahead, is driving abnormally. The surrounding information referenced here includes camera image information from a camera 31 that captures the vehicle CR[2] within its shooting range, and ranging information capable of identifying the inter-vehicle distance between the vehicles CR[2] and CR[3]. More specifically, for example, the event detection unit 117 in the in-vehicle device 1[3] may determine, based on the referenced surrounding information, whether a sudden braking event, in which the brakes of the vehicle CR[2] are suddenly applied, has occurred in the vehicle CR[2]. Furthermore, for example, the event detection unit 117 of the in-vehicle device 1[3] can determine whether an abrupt steering event, in which the steering angle of the vehicle CR[2] suddenly changes, has occurred in the vehicle CR[2] based on the referenced peripheral information. When making these determinations, the driving information of the in-vehicle device 1[3] may also be referenced.

In this way, it is advisable to enable the first vehicle (e.g., vehicle CR[3]) to detect whether an event has occurred in the second vehicle (e.g., vehicle CR[2]). This makes it possible to perform appropriate event recording processing even if a malfunction occurs in the second vehicle that prevents event detection from being performed correctly.

<<Example EX6>>
Example EX6 will be described. In each in-vehicle device 1, the event detection unit 117 may use external reference information to detect whether at least some of the first to mth events have occurred. The above-mentioned driving information, surrounding information, GPS position information, and G-sensor information (see FIG. 4) are collectively referred to as internal reference information. The internal reference information is information obtained from functional units (driving information detection unit 20, surrounding information detection unit 30, GPS processing unit 40, and acceleration sensor 50) installed in the vehicle CR. In contrast, the external reference information is information obtained from functional units outside the vehicle CR.

For example, image information captured by a fixed camera installed on a road may be included in the external reference information. Also, for example, information transmitted from a traffic light installed on the road (information indicating the signal transmitted by that traffic light) may be included in the external reference information. By referencing the image information captured by the fixed camera, it is possible to detect, for example, whether a sudden braking event has occurred. By referencing the information transmitted from the traffic light, it is possible to detect, for example, whether a red light ignition event has occurred. Each in-vehicle device 1 may be able to receive image information captured by the fixed camera and information transmitted from the traffic light using any wireless communication method.

The external reference information may include information from any external device connected to the communication network NET. The external device may include the server device 2.

The information from the external device may include, for example, weather information. The area in which the convoy is currently traveling or the area in which the convoy is scheduled to travel is referred to as the target area. The weather information includes current weather information that indicates the current weather in the target area and weather forecast information that indicates the forecast for future weather. The event detection unit 117 in any in-vehicle device 1 may detect whether a weather event has occurred based on the weather information received from the external device. The weather event may be included in the first to mth events. A weather event is, for example, an event in which a weather-related warning (such as a heavy rain warning) is issued in the target area.

The information from the external device may include, for example, disaster information. The disaster information includes current disaster information indicating disasters that have occurred at the current time in the target area and disaster forecast information indicating a fairly high possibility of a future disaster occurring. The event detection unit 117 in any in-vehicle device 1 may detect whether a disaster event has occurred based on the disaster information received from the external device. A disaster event may be included in the first to mth events. A disaster event is, for example, an event that results in the issuance of a disaster-related warning (earthquake warning, tsunami warning, etc.) in the target area. Note that weather-related warnings may also fall under the category of disaster-related warnings.

<<Example EX7>>
Example EX7 will be described. Each in-vehicle device 1 incorporates the functions of a drive recorder (platooning drive recorder). In each in-vehicle device 1, the drive recorder is configured with a main control unit 10 and a recording medium 70, and may further include all or part of a camera 31, a GPS processing unit 40, and an acceleration sensor 50. The camera 31, the GPS processing unit 40, or the acceleration sensor 50 may be understood as being provided externally to the drive recorder and connected to it. A total of n drive recorders installed in vehicles CR[1] to CR[n] form a drive recorder system (platooning drive recorder system).

The in-vehicle device 1 according to this embodiment has both a drive recorder function and a function for realizing platooning, but an in-vehicle device having only the former function may be installed in each vehicle. In this case, an in-vehicle device having the latter function is installed separately in each vehicle.

As can be understood from the above explanation, when the event detection unit 117 of a certain in-vehicle device 1[i] detects the occurrence of the jth event, an event occurrence notification signal NS is transmitted from the in-vehicle device 1[i] to each in-vehicle device 1 other than the in-vehicle device 1[i] (see Figures 9 and 11). The transmission of the event occurrence notification signal NS corresponds to an event occurrence notification issued by the event occurrence notification unit 118 of the in-vehicle device 1[i]. For the in-vehicle devices 1 other than the in-vehicle device 1[i], the event occurrence notification corresponds to a notification output from the in-vehicle device 1[i] in response to the detection of the jth event in the in-vehicle device 1[i]. Consider case CS7, in which a convoy is formed of vehicles CR[1] to CR[4], and the occurrence of the jth event is detected by the event detection unit 117 of the in-vehicle device 1[1]. The event occurrence notification here is a notification to cause the in-vehicle devices 1[2] to 1[4] to record camera image information from the cameras 31 installed in the vehicles CR[2] to CR[4] on the recording medium 70.

When such an event occurrence notification is received and the occurrence of the jth event is detected by any of the in-vehicle devices 1 (drive recorders), the event recording process will be performed in each in-vehicle device 1 (each drive recorder).

Therefore, in the in-vehicle device 1 [2] in case CS7, the recording control unit 119 sets an event recording period and performs event recording processing upon receiving an event occurrence notification. Therefore, camera image information from the camera 31 installed in vehicle CR [2] (camera image information during the event recording period) is recorded on the recording medium 70 of the in-vehicle device 1 [2]. Similarly, in the in-vehicle device 1 [3] in case CS7, the recording control unit 119 sets an event recording period and performs event recording processing upon receiving an event occurrence notification. Therefore, camera image information from the camera 31 installed in vehicle CR [3] (camera image information during the event recording period) is recorded on the recording medium 70 of the in-vehicle device 1 [3]. The same is true for the in-vehicle device 1 [4]. In case CS7, the in-vehicle device 1 [1], which is the entity that detects the occurrence of the jth event, sets an event recording period and performs event recording processing upon detecting the occurrence of the event itself. Therefore, camera image information (camera image information during the event recording period) from the camera 31 installed in the vehicle CR[1] is recorded on the recording medium 70 of the in-vehicle device 1[1].

By using event notifications to record events on all onboard devices, it is possible to record the situation of the entire convoy in detail when an event occurs. This is useful for identifying dangerous situations and analyzing accidents after the event.

In addition, in this embodiment, additional information is recorded on the recording medium 70 in addition to the camera image information during the event recording process, and information specific to platoon driving is included in the additional information (see Figures 12(a) and 12(b)). Information AD6, AD7, and AD8 shown in Figure 12(b) corresponds to information specific to platoon driving. However, information AD2, AD4, and AD5 are also types of information specific to platoon driving. By recording information specific to platoon driving (particularly information AD6, AD7, and AD8) during the event recording process, it is possible to record in detail the status of the platoon at the time an event occurs. This is useful for post-event risk scene identification and accident analysis, etc.

<<Example EX8>>
Example EX8 will now be described.

In this embodiment, as described above, when the occurrence of an event is detected, information is recorded on the recording medium 70 of each in-vehicle device 1. However, the following modified recording method may also be adopted. The modified recording method will be explained assuming case CS8 in which a convoy is formed of vehicles CR[1] to CR[3] and the occurrence of the jth event is detected by the event detection unit 117 of in-vehicle device 1[1], 1[2], or 1[3].

In case CS8, an event recording period is set in each in-vehicle device 1. In the modified recording method, one of in-vehicle devices 1[1] to 1[3] is pre-set as the representative recording device. Here, in-vehicle device 1[1] is assumed to be the representative recording device. Then, in case CS8, camera image information acquired by in-vehicle device 1[1] during the event recording period and corresponding additional information are generated within in-vehicle device 1[1] as first recording target information. In case CS8, camera image information acquired by in-vehicle device 1[2] during the event recording period and corresponding additional information are transmitted to in-vehicle device 1[1] via vehicle-to-vehicle communication as second recording target information. Similarly, in case CS8, camera image information acquired by in-vehicle device 1[3] during the event recording period and corresponding additional information are transmitted to in-vehicle device 1[1] via vehicle-to-vehicle communication as third recording target information. The recording control unit 119 of the in-vehicle device 1[1] records the first to third record target information on the recording medium 70 of the in-vehicle device 1[1] in response to the jth event related to case CS8. In this way, in the modified recording method, the information recording function is consolidated into the representative recording device. Multiple in-vehicle devices 1 may be set as the representative recording device (however, the total number of representative recording devices is less than the value of n).

Alternatively, in case CS8, the in-vehicle devices 1[1] to 1[3] may transmit the first to third record target information to the server device 2, and the server device 2 may record the first to third record target information on a recording medium (not shown) installed in or connected to the server device 2.

A computer program that causes a computer to execute the above-described method, and a computer-readable non-volatile recording medium on which that program is recorded, are included within the scope of the embodiments of the present invention. Various modifications to the embodiments of the present invention are possible, as appropriate, within the scope of the technical ideas set forth in the claims. The above-described embodiments are merely examples of embodiments of the present invention, and the meanings of the terms used in the present invention and each constituent element are not limited to those described in the above embodiments. The specific numerical values shown in the above description are merely examples, and can, of course, be changed to various numerical values.

SYS System CR, CR[1] to CR[n] Vehicle NET Communication network 1 In-vehicle device 2 Server device 10 Main control unit 11 Arithmetic processing unit 12 Internal memory 13 Communication processing unit 20 Travel information detection unit 30 Surrounding information detection unit 31 Camera (image sensor)
32 Distance measurement sensor 40 GPS processing unit 50 Acceleration sensor 60 Memory unit 70 Recording medium 80 Actuator unit 111 Vehicle information acquisition unit 112 Other vehicle information acquisition unit 113 Route setting unit 114 Travel processing unit 115 Obstacle monitoring unit 116 Formation control unit 117 Event detection unit 118 Event occurrence notification unit 119 Recording control unit

Claims (8)

A drive recorder mounted on a target vehicle included in a group of vehicles traveling in a convoy, the drive recorder having a processing unit,
The processing unit performs an acquisition process to acquire image information based on a photographing result of a camera installed in the target vehicle;
an event detection process for detecting whether one or more types of events have occurred;
an event recording process for setting an event recording period when an occurrence of any one of the events is detected, and recording the image information during the event recording period on a predetermined recording medium ;
a formation control process for controlling the formation state of the formation;
the one or more types of events include a formation state change event in which the formation state of the vehicle group is changed;
The processing unit detects whether or not the formation state change event has occurred based on the control content of the formation control process.
, drive recorder. The formation state change event is
The drive recorder according to claim 1 , wherein the event includes a convoy interruption event in which another vehicle not belonging to the convoy interrupts the convoy. The formation state change event is
an increase in the number of vehicles in the platoon;
A decrease in the number of vehicles;
The drive recorder according to claim 1 , wherein the order change includes at least one order change in which the traveling order of the platoon is changed. The drive recorder according to claim 2 or 3, wherein the occurrence of the formation state change event is detected using a sensor for observing the periphery of the convoy. Another camera and another drive recorder are installed in each of one or more vehicles in the platoon other than the target vehicle in the vehicle group,
When the occurrence of any event is detected by the event detection process , the processing unit notifies the other drive recorder to record image information based on the image capture result of the other camera on another recording medium provided in the other drive recorder.
5. The drive recorder according to claim 1 . Another drive recorder is installed in each of one or more vehicles in the platoon other than the target vehicle in the vehicle group,
A drive recorder as described in any one of claims 1 to 4, wherein when a notification is received from the other drive recorder in response to the occurrence of an event being detected in the other drive recorder, the processing unit sets the event recording period and performs the event recording process in response to receiving the notification . the processing unit , in the event recording process, associates the image information and additional information during the event recording period with each other and records them on the predetermined recording medium;
The drive recorder according to any one of claims 1 to 6, wherein the additional information includes at least one of driving order information indicating the driving order of the target vehicle in the vehicle group, and inter-vehicle distance information indicating the inter-vehicle distance between the target vehicle and a platooning vehicle other than the target vehicle in the vehicle group. A recording method executed by an on-board device mounted on a target vehicle included in a group of vehicles traveling in a convoy, comprising:
an acquisition step of acquiring image information based on a photographing result of a camera installed in the target vehicle;
an event detection step of detecting whether or not one or more types of events have occurred;
an event recording step of setting an event recording period when an occurrence of any one of the events is detected, and recording the image information during the event recording period on a predetermined recording medium;
a formation control step of controlling the formation state of the formation ,
the one or more types of events include a formation state change event in which the formation state of the vehicle group is changed;
In the event detection step, it is detected whether or not the formation state change event has occurred based on the control content in the formation control step.
, recording method .