DRIVE CONTROL SYSTEM

Abstract

A driving control system (1) comprises: a communication ECU (22) arranged in a vehicle (5) and communicating with the external environment by selectively using packet-switched communication or circuit-switched communication; a communication ECU (51) arranged in a control server (50) and communicating with the external environment by selectively using the packet-switched communication or the circuit-switched communication; a driving ECU (21) arranged in the vehicle (5) and performing autonomous driving control of the vehicle (5) based on driving environment information; a driving ECU (53) arranged in the control server (50) and performing remote driving control of the vehicle (5) based on driving environment information.When the communication ECU (51) detects a decrease in the response rate in communication with the vehicle (5) or a communication abnormality when performing the remote driving control using the packet-switched communication, the communication ECU (51) commands the vehicle (5) to switch from the remote driving control to the autonomous control using the circuit-switched communication.

Description

Technical FieldThe invention relates to a travel control system configured to perform communication regarding control information between a vehicle and a server outside the vehicle.Prior ArtIn recent years, for vehicles such as cars, travel control devices have been put into practice, which reduce the burden on the driver in travel operations and realize an increase in safety. These driving control devices are designed to assist the driver in performing driving operations. The levels of driving control (driving control) by the driving control device are defined in six degrees: level 0; level 1 (driver assistance); level 2 (semi-automated driving); level 3 (conditionally automated driving); level 4 (highly automated driving); and level 5 (fully automated driving).In order for such a travel control device to realize a higher level of travel control, it is necessary to acquire travel environment information for a wide area around the vehicle in detail and in real time. In recent years, therefore, techniques have been proposed to supplement the driving environment information acquired from, for example, an in-vehicle autonomous sensor with information from the outside of the vehicle, for example, in cooperation with a control server outside the vehicle using high-speed communication.For example, International Patent Application Publication WO 2017 / 179209 A1 discloses a vehicle control system (driving control system) having a communication device, a detector and a driver assistance controller. The communication device communicates with an external control server (server device). The detector detects a state of an environment of a subject vehicle. The driver assistance controller automatically performs at least a part of the driving control of the subject vehicle on the basis of the state of the surrounding environment of the subject vehicle. This driving control system requests, from the control server, driving environment information (environment information) related to a road on which the subject vehicle travels using the communication device. Thus, the travel control system is configured to take into account the travel environment information received from the control server in the travel control.However, in the travel control system cooperating with the external control server or the like as described above, as a safety measure against various failures, it is necessary to perform the travel control in consideration of not only failures of an in-vehicle travel control device but also communication failures between the vehicle and the control server or the like. At this time, in order to ensure a high level of convenience by the travel control, it is desirable to continue the travel control at the highest possible level even in the event of a disturbance or the like.The object of the invention is to provide a driving control system that makes it possible to establish a balance between ensuring comfort and ensuring safety.Summary of the InventionMeans for Solving the ProblemAn aspect of the invention provides a driving control system, comprising: a first communication controller configured to be disposed in a vehicle and to perform communication with the external environment by selective use of packet-switched communication or circuit-switched communication; a second communication controller configured to be disposed in a control server and to perform communication with the external environment by selective use of the packet-switched communication or circuit-switched communication; a first driving environment information detector configured to be disposed in the vehicle and to detect first driving environment information using an autonomous sensor; a second driving environment information detector configured to be disposed in the control server and to detect second driving environment information based on information detected using the packet-switched communication; a first driving controller configured to be disposed in the vehicle and to perform autonomous driving control of the vehicle based on the first driving environment information; and a second driving controller configured to be disposed in the control server and to perform remote driving control of the vehicle based on the second driving environment information. When the second driving control detects a decrease in the response rate in communication with the vehicle or a communication abnormality in performing the remote driving control using the packet-switched communication, the second driving control instructs the vehicle to change from the remote driving control to the autonomous driving control using the circuit-switched communication.Brief Description of the DrawingsThe drawings show in: FIG. 1 is an overall configuration of a driving control system. FIG. 2 is a schematic diagram of an area in which driving environment information is acquired from a first group of autonomous sensors. FIG. 3 is a schematic diagram of an area in which driving environment information is acquired from a second group of autonomous sensors. FIG. 4 is an illustrative illustration of the area covered by the driving environment information acquired from each group of autonomous sensors and a control server. FIG. 5 is an illustrative schematic illustration of a communication system of the driving control system. FIG. 6 is an illustrative view of a remote control inhibiting portion. FIG. 7 is a flowchart showing a routine of determining a decrease in the response rate in communication between the vehicle and the control server. FIG. 8 is a flowchart showing a routine of malfunction countermeasure control in a communication malfunction between the vehicle and the control server. FIG. 9 is a flowchart (part 1) of a routine of the failure countermeasure control in a communication failure in a control area. FIG. 10 is a flowchart (part 2) of the failure countermeasure control routine in a communication failure in the control area. FIG. 11 is a flowchart showing a routine of the failure countermeasure control in a vehicle failure.Embodiments of the InventionHereinafter, some embodiments of the invention will be described with reference to the drawings. The drawings relate to an embodiment of the invention, and FIG. 1 is an overall configuration of a travel control system.As illustrated in FIG. 1, a driving control system 1 according to this embodiment includes a driving controller 10, a plurality of control servers 50, and an off-vehicle driving controller 70. The travel control device 10 is mounted on a vehicle 5 as a moving body. The plurality of control servers 50 include narrow area servers disposed in a network environment. The vehicle-external travel controller 70 performs travel control of the vehicle 5 via the control servers 50.The travel control device 10 includes, for example, a stereo camera unit 11, a plurality of corner radars 12, a LIDAR (Light Detection and Ranging) 13, and an omnidirectional camera 14 as autonomous sensing devices that are disposed in the vehicle 5 and sense the travel environment. Further, the travel control device 10 includes, as various control units, a positioning control unit (hereinafter referred to as "positioning ECU") 20, a travel control unit (hereinafter referred to as "travel ECU") 21, a communication control unit (hereinafter referred to as "communication ECU") 22, an engine control unit (hereinafter referred to as "E / G ECU") 23, a power steering control unit (hereinafter referred to as "PS-ECU") 24, a brake control unit (hereinafter referred to as "BK-ECU") 25, and an alarm control unit (hereinafter referred to as "alarm ECU") 26. These control units 20 to 26 are coupled to each other via an in-vehicle communication line such as a CAN (Controller Area Network).According to this embodiment, the stereo camera unit 11, the plurality of corner radars 12, the LIDAR 13, the omnidirectional camera 14, and the positioning ECU 20 correspond to a specific example of a first traveling environment information detector.The stereo camera unit 11 is mounted, for example, at the center of the upper portion of the front portion of a cabin. This stereo camera unit 11 includes, for example, an in-vehicle camera (stereo camera) including a main camera 11 aand a sub camera 11 b, an image processing unit (IPU) 11 c, and an image recognition control unit (hereinafter referred to as "image recognition ECU") 11 d.For example, the main camera 11 aand the sub camera 11 bexecute the capturing of a real space in front of the vehicle 5 from various view angles on the left and right sides. Thus, the main camera 11 aand the sub camera 11 bare arranged at horizontally symmetric positions, e.g., across the vehicle width center of the vehicle 5.The IPU 11 cprocesses, as predetermined, a pair of left and right images (stereo images) stereo taken by both cameras 11 aand 11 bto generate distance image information. That is, the IPU 11 ccalculates a value of the positional deviation between pixels indicating the same object in the left and right images. Thus, the IPU 11 ccalculates the distance from the vehicle 5 to the pixel indicating an object outside the vehicle. Thus, the IPU 11 cgenerates image information (distance image information) in which each pixel indicating a target outside the vehicle includes distance information.For example, the image recognition ECU 11 dperforms predetermined pattern matching with respect to the distance image information. Thus, for example, the image recognition ECU 11 dacquires a lane line that divides the road. Further, the image recognition ECU 11 drecognizes three-dimensional objects such as guardrails and curbs located along the road as well as pedestrians, two-wheeled vehicles, and other on-road vehicles as two-wheeled vehicles. Here, the recognition of three-dimensional objects in the image recognition ECU 11 dincludes, for example, the recognition of the type of the three-dimensional object, the distance to the three-dimensional object, the speed of the three-dimensional object, and the like.The corner radars 12 are disposed, for example, at the left and right side regions of a front bumper and at the left and right side regions of a rear bumper of the vehicle 5. These corner radars 12 include millimeter wave radars, for example. In this case, each corner radar 12 emits radar waves in the horizontal direction in each predetermined frame period, and receives reflected waves of the emitted radar waves. Thus, each corner radar 12 detects a plurality of reflection points on a three-dimensional object located in the vicinity of the subject vehicle 5.Further, each corner radar 12 groups, as predetermined, the detected plurality of reflection points to recognize the three-dimensional object. Further, each corner radar 12 specifies, as a representative point of the three-dimensional object, a reflection point that is the smallest straight distance from the reflection points on the recognized three-dimensional object to the subject vehicle 5. Thus, for example, each corner radar 12 recognizes a position and a moving speed of the reflection point corresponding to the representative point as information regarding the representative point, and recognizes a size of the three-dimensional object calculated from the distribution of the reflection points.Here, as illustrated in FIG. 2, for example, at least a part of a monitoring range of the stereo camera unit 11 and at least a part of a monitoring range of each corner radar 12 are superimposed on each other. Thus, the stereo camera unit 11 and each corner radar 12 constitute a first group of autonomous sensors for detecting the driving environment information around the vehicle 5.The LIDAR 13 is disposed, for example, in the center of the front region of the vehicle 5. For example, the LIDAR 13 emits pulsed laser light in the near infrared region and measures the reflected light from a target. Thus, the LIDAR 13 accurately detects not only the distance to the target but also the position and the shape of the object.Note that, similar to the stereo camera unit 11, the LIDAR 13 is a sensor that outputs a distance point group. However, since the stereo camera unit 11 is a passive sensor, the stereo camera unit 11 has an advantage of a higher sampling rate than the LIDAR 13. In contrast, since the LIDAR 13 is an active sensor, the LIDAR 13 has an advantage of stable detection accuracy with respect to brightness changes, as compared to the stereo camera 11. Accordingly, according to this embodiment, the stereo camera unit 11 and the LIDAR 13 are in complementary relation to each other.The omni-directional camera 14 includes a plurality of cameras 14 a. The cameras 14 aare arranged, for example, in the center of the front region of the vehicle 5, on the left and right exterior mirrors of the vehicle 5, and in the center of the rear region of the vehicle 5. The cameras 14 aeach detect three-dimensional objects outside the vehicle, for example, by known image recognition processing.Here, as illustrated in FIG. 3, for example, at least a part of the monitoring range of the LIDAR 13 and at least a part of a monitoring range of the omnidirectional camera 14 are superimposed on each other. Thus, the LIDAR 13 and the omni-directional camera 14 form a second group of autonomous sensors for detecting the driving environment information regarding the environment of the vehicle 5.Note that, according to this embodiment, all the travel environment information detected by the stereo camera unit 11, each corner radar 12, the LIDAR 13, and the omnidirectional camera 14 are output to the travel ECU 21, for example. Further, all the travel environment information is transmitted from the travel ECU 21 to the positioning ECU 20 and the communication ECU 22, for example, via the in-vehicle communication line such as the CAN.The positioning ECU 20 estimates the position of a subject vehicle on a road map. To this end, sensors such as an acceleration rate sensor 15, speed sensors (wheel speed sensors) 16, a gyro sensor 17, and a GNSS receiver 18 are coupled to the positioning ECU 20. The sensors are required for calculating the position coordinates of the vehicle 5 in question. At this time, the acceleration rate sensor 15 detects acceleration of the vehicle 5. the speed sensors 16 detect the rotational speeds of a front left wheel, a front right wheel, a rear left wheel, and a rear right wheel. The gyro sensor 17 detects an angular velocity or an angular acceleration rate of the subject vehicle. The GNSS receiver 18 receives position signals transmitted from multiple positioning satellites.Further, a road map database 20a is coupled to the positioning ECU 20. The road map database 20 aincludes, for example, a mass storage medium such as an HDD. The road map database 20 astores information on high-precision road maps (dynamic map) as travel environment information. The road map information includes three information layers, e.g., static information, semidynamic information, and dynamic information. The static information is mainly road information. The semidynamic information and the dynamic information are mainly traffic information.The static information includes, for example, information to be updated at a frequency of less than once a month, for example, roads and structures on the roads, lane information, road surface information, and information related to permanent regulations.The semidynamic information includes, for example, information to be updated at a frequency of one minute, e.g., current congestion states and traffic restrictions at the time of observation, states of temporary traffic obstacles such as falling objects and obstacles, current accident states, and weather information for a narrow area.The dynamic information includes, for example, information to be updated at a frequency of one second, for example, information to be transmitted and exchanged between mobile bodies, information regarding the current signaling of traffic lights, information regarding pedestrians and two-wheeled vehicles at intersections, information regarding vehicles passing through the intersection straight.Note that the positioning ECU 20 updates the information in each of the layers constituting the road map information in real time based on the driving environment information acquired by the various autonomous sensing devices. Further, the positioning ECU 20 updates the information in each of the layers constituting the road map information in real time on the basis of the road map information (traveling environment information) received from the control server 50 or the like by the communication ECU 22 described later.Here, the driving environment information received from the control server 50 via the communication ECU 22 is information on a wider range than the driving environment information acquired by the various autonomous sensing devices. Specifically, for example, as illustrated in FIG. 4, each of the autonomous sensing devices is configured to sense at most driving environment information covering an area in which the vehicle 5 travels for three seconds. On the other hand, the travel environment information received from the control server 50 is, for example, wider area information that covers an area in which the vehicle 5 travels for 30 seconds.The driving ECU 21 calculates various kinds of control information to perform autonomous driving control (driving control) based on the above-described driving environment information.For example, the travel ECU 21 calculates, as control information, a target acceleration / deceleration rate to perform adaptive cruise control (ACC) based on the travel environment information and the like. That is, when a preceding vehicle is in front of the vehicle 5, the driving ECU 21 calculates the target acceleration / deceleration rate so that the vehicle 5 can follow the preceding vehicle.Further, when there is no preceding vehicle in front of the vehicle 5, the driving ECU 21 calculates the target acceleration / deceleration rate so that the vehicle 5 can travel at a constant speed at a predetermined vehicle speed. Further, the travel ECU 21 outputs the calculated target acceleration / deceleration rate to the E / G ECU 23 and BK ECU 25. Thus, the I / O ECU 23 and the BK ECU 25 are configured to perform acceleration / deceleration control based on the target acceleration / deceleration rate.Further, the driving ECU 21 calculates, as control information, a target steering angle to perform active lane keep centering (ALKC) based on the driving environment information and the like. That is, the travel ECU 21 calculates the target steering angle to keep the subject vehicle in the middle of a lane of the subject vehicle, based on the travel environment information and the like. Further, the travel ECU 21 outputs the calculated target steering angle to the PS-ECU 24. Thus, the PS-ECU 24 is configured to perform steering control based on the target steering angle.Further, the travel ECU 21 calculates, as control information, a target deceleration rate, for example, to perform emergency brake control based on the travel environment information. That is, the travel ECU 21 calculates, for example, the collision time period TTC (=(relative distance) / (relative speed)) with respect to an obstacle located in front of the vehicle 5.Further, the travel ECU 21 calculates the target deceleration rate when the collision time period TTC becomes equal to or less than a predetermined threshold value. Further, the travel ECU 21 outputs the calculated target deceleration rate to the BK ECU 25. Thus, the BK-ECU 25 is configured to perform deceleration control based on the target deceleration rate. Further, in the calculation of the target deceleration rate, the travel ECU 21 outputs an alarm command to the alarm ECU 26. Thus, the alarm ECU 26 is configured to perform alarm control for an occupant.Further, the travel ECU 21 is configured to perform, for example, lane change control for changing the lane of the vehicle 5 and emergency steering control for avoiding a collision between the vehicle 5 and an obstacle.The driving ECU 21 is configured to realize the driving control (autonomous driving control) by an appropriate combination of a plurality of controls including each of these controls. As described, the travel ECU 21 according to this embodiment corresponds to a specific example of first travel control.Here, the levels of the driving control according to this embodiment are defined in six degrees: level 0 (no automated driving); level 1 (driver assistance); level 2 (semi-automated driving); level 3 (conditionally automated driving); level 4 (highly automated driving); and level 5 (fully automated driving). These stages of the travel control are designed to change stepwise, for example, according to the state of acquisition (reliability, etc.) of the travel environment information.Here, the driving environment information acquired from the first autonomous sensor group is defined as "Ide1", the driving environment information acquired from the second autonomous sensor group is defined as "Ide2", and the driving environment information received from the control server 50 is defined as "Ide3". Then, the reliability of the travel environment information is, for example, in the following order.For example, the travel ECU 21 is configured to change the stages of the travel control stepwise according to the reliability of the travel environment information thus changing.To the communication ECU 22, a transceiver 19 as a communication device is coupled to perform "communication that couples a vehicle to everything". Here, "communication that couples a vehicle to everything" refers to, for example, a V2X cellular communication or a communication form in which 4G or 5G network access technology and short-range communication (DSRC) technology or even V2X cellular communication (C-V2X) technology are integrated. According to this embodiment, "everything to be coupled to the vehicle 5", e.g., the control server 50, includes other vehicles around the vehicle 5 and portable terminals.The transceiver 19 is configured to perform packet-switched communication using, for example, the HTTP (Hypertext Transfer Protocol) protocol or the MQTT (Message Queue Telemetry Transport) protocol.The communication ECU 22 is configured to transmit, to the control server 50, in real time, various kinds of information indicating the state of the vehicle 5 (such as the speed, the acceleration rate, the traveling direction, position information, and a failure code of the vehicle 5), for example, by this packet-switched communication. Further, the communication ECU 22 is configured to transmit, to the control server 50, the driving environment information detected by the various autonomous sensing devices of the vehicle 5, for example, in real time.Further, the communication ECU 22 is configured to receive, in real time, for example, the control information (described later) for performing travel control of the remote control type vehicle 5 from the control server 50. Further, the communication ECU 22 is configured to receive, in real time, the travel environment information regarding the environment of the vehicle 5, for example, from the control server 50.Further, the transceiver 19 is configured to perform circuit-switched communication using, for example, the SMPP (Short Message Peer to Peer) protocol. This circuit-switched communication is designed to enable stable communication even in an emergency or a disaster with a small amount of data, as compared with packet-switched communication. Thus, circuit switched communication is used especially when, for example, an abnormality occurs in packet switched communication.As described, the communication ECU 22 according to this embodiment corresponds to a specific example of a first communication control.To the output side of the I / O ECU 23, a throttle actuator 27 and the like are coupled. The throttle actuator 27 causes opening and closing of a throttle valve of an electronically controlled throttle disposed in a throttle body of an engine. That is, the throttle actuator 27 effects the opening and closing operation of the throttle valve by a drive signal from the E / G ECU 23. Thus, the throttle actuator 27 adjusts an intake air rate and generates a desired engine output.To the output side of the PS-ECU 24, a motor 28 for electric power steering and the like is coupled. The electric power steering motor 28 applies a steering torque to a steering mechanism. That is, the electric power steering motor 28 generates a desired steering angle by a control signal from the PS-ECU 24.To the output side of the BK-ECU 25, a brake actuator 29 and the like are coupled. The brake actuator 29 adjusts the brake hydraulic pressure applied to a wheel brake cylinder disposed in each wheel. That is, when driven by a control signal from the BK-ECU 25, the brake actuator 29 generates a braking force for each wheel through the wheel brake cylinder.To the output side of the alarm ECU 26, an alarm device 30 and the like are coupled. The alarm device 30 outputs a predetermined alarm to a driver. Here, the alarm device 30 includes, for example, a multi-information display device, a speaker, or the like, which are disposed on an instrument panel. That is, the alarm device 30 gives a predetermined alarm display to the driver or gives an alarm sound to the driver by a control signal from the alarm ECU 26.Here, the ECUs such as the I / O ECU 23, the PS-ECU 24, the BK-ECU 25, and the alarm ECU 26 each have a self-diagnostic function. When a predetermined failure is detected by the self-diagnosis of each ECU, each ECU outputs a predetermined failure code or the like to the communication ECU 22.The control server 50 is arranged for each predetermined control area, for example. The control server 50 is, for example, an edge server (so-called MEC server) of a network environment by edge computing.The control server 50 includes, as various control units, for example, a communication control unit (hereinafter referred to as "communication ECU") 51, an information recognition control unit (hereinafter referred to as "information recognition ECU") 52, a travel control unit (hereinafter referred to as "travel ECU") 53, and an integrated control unit (hereinafter referred to as "integrated ECU") 54. These ECUs 51 to 54 are coupled to each other via a predetermined communication line. Here, each of the ECUs 51 to 54 has specifications with higher performance than each ECU to be mounted in the vehicle 5. Further, the programs for controlling each of the ECUs 51 to 54 are configured to be constantly updated to the latest programs.A transceiver 55 as a communication device is coupled to the communication ECU 51.The transceiver 55 is configured to perform the packet-switched communication using, for example, the HTTP protocol or the MQTT protocol.The communication ECU 51 is configured to perform packet-switched communication with, for example, the plurality of vehicles 5 located in the control area, the vehicle-external travel control device 70, and various sensor devices (not illustrated) installed along the road, in a parking lot, and the like by this transceiver 55.For example, the communication ECU 51 is configured to perform packet-switched communication with the transceiver 19 mounted on each vehicle 5 using the transceiver 55. Thus, the communication ECU 51 is configured to receive, in real time, the various kinds of information indicating the state of each vehicle 5 (such as the speed, the acceleration rate, the traveling direction, the position information, and the trouble code of the vehicle 5). Further, the communication ECU 51 is configured to receive the driving environment information detected by the autonomous sensing devices of each vehicle 5 in real time. Further, the communication ECU 51 is configured to transmit the individual control information for each vehicle 5 to each vehicle 5 in real time.Further, the transceiver 55 is configured to perform the circuit-switched communication using, for example, the SMPP protocol.The communication ECU 51 is configured by this transceiver 55 to perform the circuit-switched communication with, for example, the plurality of vehicles 5 located in the control area, the vehicle-external travel control device 70, and the various sensor devices (not illustrated) installed along the road, in a parking lot, and the like.For example, the communication ECU 51 is configured to perform the circuit-switched communication with the transceiver 19 mounted on each vehicle 5 using the transceiver 55. This enables the communication between the control server 50 and each vehicle 5 (the travel controller 20) to be maintained as predetermined even when an abnormality occurs in the packet-switched communication.As described, the communication ECU 51 in the embodiment corresponds to a specific example of a second communication control.The information recognition ECU 52 recognizes, in real time, the travel environment information in the control area, for example, on the basis of the travel environment information acquired from each vehicle 5, the various detectors, and the like by the packet-switched communication. The recognition of the travel environment information is performed, for example, by sequentially updating the road map information based on the acquired travel environment information.Accordingly, a road map database 52 ais coupled to the information recognition ECU 52. In this road map database 52 a, high-precision road map information (dynamic map) is stored as travel environment information as in the in-vehicle road map database 52 a. Further, the information recognition ECU 52 recognizes the travel environment information by updating the road map information in real time using the travel environment information received (acquired) from the communication ECU 51. The travel environment information thus recognized is transmitted from the communication ECU 51 to each vehicle 5 by packet-switched communication.Here, for example, as illustrated in FIG. 6, a remote control prohibition area is set in the road map information in advance. The remote control inhibiting portion is configured to inhibit remote driving control described later. As this suppression area, for example, the following areas are set: an area in which a radio wave state is constantly bad; an area in which monitoring by the various detection devices such as a camera is obstructed by a shielding object such as a wall; an area in which pedestrians or the like pass, for example, a pedestrian crossing; and the like.As described, the information recognition ECU 52 according to this embodiment corresponds to a specific example of a second traveling environment information acquirer.The travel ECU 53 is configured to perform the travel control (remote travel control) of each vehicle 5 from a remote location. Here, the driving ECU 53 is configured to replace the entire autonomous driving control to be performed by the in-vehicle driving ECU 21 by the remote driving control. Alternatively, the driving ECU 53 is configured to replace a part of the autonomous driving control to be performed by the in-vehicle driving ECU 21 by the remote driving control.Thus, the travel ECU 53 calculates various kinds of control information to perform the remote travel control of each vehicle 5 located in the control area. In this case, the travel ECU 53 calculates various kinds of control information based on, for example, the travel environment information (road map information) and the like updated in the information recognition ECU 52 in real time. The calculation of this control information is similar to the calculation of the control information to be performed by the in-vehicle driving ECU 21 for performing the autonomous driving control, for example. However, the calculation of the various kinds of control information by the travel ECU 53 is limited with respect to the vehicle 5 located in the remote control prohibition area.As described, the travel ECU 53 according to this embodiment corresponds to a specific example of second travel control.The in-vehicle travel controller 70 has, for example, the function of serving as a substitute for performing the remote travel control of each vehicle 5 to be performed by the travel ECU 53 of the control server 50. The out-of-vehicle travel controller 70 includes, for example, a communication control unit (hereinafter referred to as "communication ECU") 71 and a travel control unit (hereinafter referred to as "travel ECU") 72.A transceiver 73 as a communication device is coupled to the communication ECU 71.The transceiver 73 is configured to perform the packet-switched communication using, for example, the HTTP protocol or the MQTT protocol.The communication ECU 71 is configured to perform packet-switched communication with, for example, the control server 50 through the transceiver 73.For example, the communication ECU 71 is configured to receive, for example, the traveling environment information recognized by the information recognition ECU 52 in real time. Further, the communication ECU 71 is configured to transmit, for example, the control information regarding a specific vehicle 5 to the control server 50 in real time.Further, the transceiver 73 is configured to perform the circuit-switched communication using, for example, the SMPP protocol.The communication ECU 71 is configured to perform the circuit-switched communication with, for example, the control server 50 by this transceiver 73.Thus, the communication between the off-vehicle travel controller 70 and the control server 50 can be maintained as predetermined even when an abnormality occurs in the packet-switched communication.As described, the communication ECU 71 according to this embodiment corresponds to a specific example of third communication control.The travel ECU 72 is configured to execute the function of the travel ECU 53 of the control server 50 to perform the travel control (remote travel control) of the specific vehicle 5. In this case, the travel ECU 72 calculates various kinds of control information based on, for example, the travel environment information (road map information) and the like received from the control server 50 by the communication ECU 71 in real time. The calculation of this control information is similar to the calculation of the control information for performing the autonomous driving control to be performed by the in-vehicle driving ECU 21, for example.As described, the travel ECU 72 according to this embodiment corresponds to a specific example of third travel control.Note that, in the off-vehicle travel control device 70, an operation input device (not illustrated) such as a touch screen or an operation lever may also be provided as a third travel control instead of the travel ECU 72. In this case, the user or the like on the off-vehicle travel control device 70 operates the operation input device on the basis of the travel environment information to perform the remote travel control (remote control operation) of the vehicle 5.Next, countermeasures against failures (safety measures) when various failures occur in the driving control system 1 configured as described during execution of the remote driving control will be described.In order to realize the countermeasures against failures in the remote driving control, the communication ECU 22 of the vehicle 5 (the driving controller 10) performs monitoring for communication failures with the control server 50. For example, the communication ECU 22 periodically transmits a PING command to the control server 50 using the packet-switched communication.Thus, when it is determined that the communication response rate from the control server 50 decreases, the communication ECU 22 notifies the control server 50 of the decrease in the communication response rate by means of the circuit-switched communication using the transceiver 19. Here, a state in which the communication response rate decreases refers to a state in which, for example, although the packet-switched communication is established, a communication speed has decreased to a level not sufficient to perform appropriate remote driving control. Accordingly, the packet-switched communication continues as predetermined even when the communication response rate decreases.When the communication ECU 51 of the control server 50 is notified of a decrease in the communication response rate, it instructs the corresponding vehicle 5 to switch from the remote driving control to the autonomous control. That is, the communication ECU 51 interrupts the remote driving control before an abnormality occurs in the packet-switched communication, and shifts the driving control of the vehicle 5 to the autonomous driving control. Further, when the remote driving control (remote control operation) of the subject vehicle 5 is performed by the off-vehicle driving controller 70, the communication ECU 51 requests the off-vehicle driving controller 70 to end the remote driving control.Further, the communication ECU 51 of the control server 50 monitors the reliability of communication with the vehicle 5. Thus, the communication ECU 51 determines that an abnormality has occurred in packet-switched communication with the vehicle 5 when the frequency of packet reception from the vehicle 5 decreases and the communication reliability decreases.When it is determined that the communication reliability decreases, for example, the communication ECU 51 instructs the corresponding vehicle 5 to perform an emergency stop by the autonomous driving control. Further, the communication ECU 51, for example, instructs the out-of-vehicle travel controller 70 to stop the remote travel control. Further, the communication ECU 51 notifies vehicles, pedestrians, or the like in the environment of the presence of the vehicle having an abnormality through simultaneous notification.Further, the communication ECU 51 of the control server 50 performs monitoring for communication troubles in the control area. Thus, for example, the communication ECU 51 determines the reliability of packet-switched communication with each vehicle 5 located in the control area. Further, the communication ECU 51 determines, for each lane in the control area, a communication disturbance level based on the reliability of communication with each vehicle 5.Further, when receiving a trouble code from the vehicle 5, the communication ECU 51 instructs the subject vehicle 5 to stop the vehicle coming into an emergency situation, and requests those around the vehicle 5 to take countermeasures against the vehicle having the trouble.Next, a determination of communication trouble (determination of a decrease in communication response rate) between the vehicle 5 and the control server 50 to be performed by the communication ECU 22 will be described with reference to a flowchart of a communication response rate determination routine illustrated in FIG. 7.This routine is repeatedly executed in the communication ECU 22 at every predetermined time. At the start of the routine, the communication ECU 22 transmits a PING command to the control server 50 in step S 101. More specifically, the communication ECU 22 transmits a PING command of the control server 50 to the transceiver 55 by means of the packet-switched communication using the transceiver 19.In subsequent step S 102, the communication ECU 22 calculates a moving average of the RTT (round trip time) of the PING command in the latest predetermined time (e.g., the latest 10 seconds).In subsequent step S 103, the communication ECU 22 checks whether or not a decrease in communication response rate has occurred between the vehicle 5 and the control server 50 based on the moving average of the RTT.Further, when it is determined in step S 103 that no decrease in communication response rate has occurred (step S 103: NO), the communication ECU 22 ends the routine as it is.On the other hand, when it is determined in step S 103 that a decrease in communication response rate has occurred (step S 103: YES), the communication ECU 22 causes the flow to proceed to step S 104.Further, in step S 104, the communication ECU 22 notifies the control server 50 of the decrease (abnormality) in the communication response rate, and thereafter ends the routine. In this case, the communication ECU 22 notifies the control server 50 of the decrease in communication response rate, for example, by means of the circuit-switched communication (SMS communication) using the transceiver 19. This is because such circuit switched communication enables more stable communication than the packet switched communication.Next, failure countermeasure control in the case of communication failure between the vehicle 5 and the control server 50 will be described with reference to a flowchart of the failure countermeasure control routine illustrated in FIG. 8. Note that this disturbance countermeasure control is repeatedly executed, for example, at each time predetermined in the communication ECU 51 of the control server 50. In this case, the communication ECU 51 performs the disturbance countermeasure control for each vehicle 5 according to a communication disturbance determined individually between each vehicle 5 and the control server 50. Accordingly, the disturbance countermeasure control is hereinafter individually executed for each vehicle 5.At the start of the routine, the communication ECU 51 calculates the reliability of communication with the vehicle 5 in step S 201. The communication reliability is calculated based on, for example, the number of times the transceiver 55 receives packet data per unit time from the vehicle 5. In this case, the lower the frequency with which the transceiver 55 receives the packet data per unit time from the vehicle 5, for example, the lower the calculated communication reliability.In subsequent step S 202, the communication ECU 51 checks whether or not a decrease in communication reliability calculated in step S 201 described above has occurred. That is, the communication ECU 51 determines, when, for example, the communication reliability is less than a predetermined threshold value, that general socket communication by the packet-switched method has failed and that a decrease in the communication reliability has occurred.Thus, when it is determined in step S 202 that a decrease in reliability of communication with the vehicle 5 by the packet-switched communication has occurred (step S 202: YES), the communication ECU 51 causes the flow to proceed to step S 207.On the other hand, when it is determined in step S 202 that there has been no decrease in reliability of communication with the vehicle 5 by the packet-switched communication (step S 202: NO), the communication ECU 51 causes the flow to proceed to step S 203.In step S 203, the communication ECU 51 checks whether or not a decrease in the communication response rate has occurred. That is, even in a case where general socket communication is performed by the packet-switched method, it is difficult to perform appropriate remote driving control when the level of communication performance required for remote driving control is not satisfied. Accordingly, the communication ECU 51 determines whether or not the communication response rate calculated in the communication ECU 22 of the vehicle 5 has decreased.Further, when it is determined in step S 203 that the communication response rate is equal to or higher than a threshold and that no decrease in the communication response rate has occurred (step S 203: NO), the communication ECU 51 causes the flow to proceed to step S 204.When the flow advances from step S 203 to step S 204, the communication ECU 51 transmits various kinds of control information for the remote driving control calculated by the driving ECU 53 to the vehicles 5 by the packet-switched communication using the transceiver 55.On the other hand, when it is determined in step S 203 that the communication response rate is less than the threshold and that a decrease in the communication response rate has occurred (step S 203: YES), the communication ECU 51 causes the flow to proceed to step S 205.When the flow advances from step S 203 to step S 205, the communication ECU 51 requests the vehicle 5 to start the autonomous driving control. At this time, when the communication response rate has decreased, the possibility that the level of communication performance required for remote driving control is no longer reached is high. On the other hand, even in a case where the communication response rate has decreased, when the communication reliability is maintained as predetermined, the probability is high that a communication level at which the travel environment information is received from the control server 50 by the transceiver 19 is maintained.Accordingly, the driving ECU 21 of the vehicle 5 performs the autonomous driving control based on the driving environment information, and the driving environment information received from the control server 50 is added to the driving environment information acquired from the various autonomous sensing devices or the like. Thus, the communication ECU 51 performs a transition of the driving control from the remote driving control to the autonomous driving control before the communication reliability decreases (before a communication abnormality occurs).Further, when the flow advances from step S 205 to step S 206, the communication ECU 51 requests the out-of-vehicle travel controller 70 to end the remote control operation, and thereafter ends the routine. Thus, when there is a user (remote control operator) who performs the remote control operation of the vehicle 5 using the off-vehicle travel controller 70, the subject remote controller is notified of the request to end the remote control operation.At this time, the above-described communication in steps S205 and S206 is performed using, for example, the circuit-switched communication. That is, the communication ECU 51 gives, for example, the command to change the travel control using the circuit-switched communication while maintaining transmission and reception of the travel environment information using the packet-switched communication.When the flow advances from step S 202 to step S 207, the communication ECU 51 notifies the vehicle 5 of the occurrence of abnormality in communication with the control server 50.In subsequent step S 208, the communication ECU 51 notifies the off-vehicle travel controller 70 of the occurrence of an abnormality in communication between the vehicle 5 and the control server 50. Thus, when the remote driving control of the vehicle 5 is executed by, for example, the driving ECU 71 of the off-vehicle driving controller 70, the corresponding remote driving control is stopped.In subsequent step S 209, the communication ECU 51 notifies other vehicles and pedestrians located in the vicinity of the vehicle 5 of the presence of a vehicle having an abnormality or guides other vehicles and pedestrians to a safe avoidance location, and thereafter ends the routine.At this time, the above-described communication in steps S 207 and S 208 is performed using, for example, the circuit-switched communication.Further, the above-described communication in step S 209 is performed, for example, by simultaneous distribution using the circuit-switched communication.Next, the failure countermeasure control in a communication abnormality in the control area will be described with reference to the flowcharts of the failure countermeasure control routine illustrated in FIGS. 9 and 10. Here, while the above-described control of FIG. 8 is interference countermeasure control against each communication interference between each vehicle 5 and the control server 50, the control illustrated in FIGS. 9 and 10 includes performing the interference countermeasure control after comprehensively determining a communication interference for each lane in the control area. This routine is repeatedly executed, for example, at every predetermined time in the communication ECU 51. Further, this routine is individually executed, for example, for each lane in the control area.At the start of the routine, the communication ECU 51 calculates the communication reliability with respect to the traveling lane as the current target in the control area, based on the communication reliability calculated for each vehicle 5 in the control area.The communication reliability in each lane is calculated based on the communication reliability of each in-lane vehicle 5. For example, the communication ECU 51 calculates an average value of the reliability of packet-switched communication between each in-lane vehicle 5 and the control server 50 as the communication reliability with respect to the lane.Alternatively, the communication ECU 51 calculates the smallest value of the reliability of packet-switched communication between each in-lane vehicle 5 and the control server 50 as the communication reliability with respect to the lane.In subsequent step S 302, the communication ECU 51 checks whether or not the communication reliability with respect to the traveling lane has fallen below a threshold value.Further, when it is determined in step S 302 THAT THE COMMUNICATION RELIABILITY IS EQUAL TO OR HIGHER THAN THE THRESHOLD (STEP S 302: NO), the communication ECU 51 causes the flow to proceed to step S 330.In step S 303, the communication ECU 51 determines that there is no communication failure in the target lane, and then ends the routine.On the other hand, when it is determined in step S 302 that the communication reliability is below the threshold (step S 302: YES), the communication ECU 51 causes the flow to proceed to step S 304.In step S 304, the communication ECU 51 selects a distribution protocol related to the vehicles 5 in the traveling lane. That is, even in a case where the reliability of the packet-switched communication has decreased, when it is possible to distribute a command to each vehicle 5 in the lane using the packet-switched communication, the communication ECU 51 selects the packet-switched communication as a distribution protocol. On the other hand, when it is difficult to distribute a command to each vehicle 5 in the lane using the packet-switched communication, the communication ECU 51 selects the circuit-switched communication as a distribution protocol.In subsequent step S 305, the communication ECU 51 checks the elapsed time from the drop of the communication reliability with respect to the traveling lane below the threshold.Further, in step S 306, the communication ECU 51 checks whether or not a long time (predetermined time or longer) has elapsed since the communication reliability with respect to the traveling lane has decreased below the threshold.Further, when it is determined in step S 306 that a long time has elapsed (step S 306: YES), the communication ECU 51 causes the flow to proceed to step S 309.On the other hand, when it is determined in step S 306 that a long time has not elapsed (step S 306: NO), the communication ECU 51 causes the flow to proceed to step S 307.In step S 307, the communication ECU 51 determines the communication disturbance level with respect to the target lane as "1.". Here, communication failure level 1 means, for example, occurrence of a short-term range-limited communication failure (communication interruption) with respect to the target lane.In subsequent step S 308, the communication ECU 51 instructs each vehicle 5 on the target lane to perform automated driving under WP (Path Point) control using the communication protocol selected in step S 304, and thereafter causes the flow to return to step S 301. That is, the communication ECU 51 instructs each vehicle 5 to continue automated driving on the basis of various kinds of information (e.g., the driving environment information) shared with the control server 50.When the flow advances from step S 306 to step S 309, the communication ECU 51 determines the communication disturbance level with respect to the target lane as "2". Here, communication disturbance level 2 means, for example, the occurrence of a long-term area-limited communication disturbance with respect to the driving lane.In subsequent step S 310, the communication ECU 51 instructs each vehicle 5 on the target lane to disable the automated driving using the communication protocol selected in step S 304, and thereafter causes the flow to proceed to step S 311. At this time, the communication ECU 51 instructs each vehicle 5 to decelerate to, for example, a predetermined speed to disable the automated driving. Alternatively, as a command to disable automated driving, for example, the communication ECU 51 commands each vehicle 5 to stop a predetermined control element.In subsequent step S 311, the communication ECU 51 refers to a radio wave map predetermined in advance and confirms an area where the communication service is provided. Further, the communication ECU 51 calculates the communication reliability in each lane other than the target lane by a similar process as in step S 301.In subsequent step S 312, the communication ECU 51 checks whether or not the target lane is in the area where the communication service is provided, based on the radio wave map.Further, when it is determined in step S 312 that the lane is outside the area where the service is provided (step S 312: NO), the communication ECU 51 causes the flow to proceed to step S 316.On the other hand, when it is determined in step S 312 that the lane is within the range in which the service is provided (step S 312: YES), the communication ECU 51 causes the flow to proceed to step S 313.In step S 313, the communication ECU 51 checks whether there are other lanes in which the communication failure has occurred in addition to the target lane.Further, when it is determined in step S 313 that there are no other lanes in which the communication failure has occurred (step S 313: NO), the communication ECU 51 causes the flow to return to step S 331.On the other hand, when it is determined in step S 313 that there are other lanes in which the communication failure has occurred (step S 313: YES), the communication ECU 51 determines the communication failure level with respect to the target lane as "3". Here, communication disturbance level 3 means, for example, occurrence of a long-term communication disturbance (extensive communication disturbance) in an extensive area including the target lane.In subsequent step S 315, the communication ECU 51 instructs each vehicle 5 on the target lane to perform the automated driving mainly on the basis of the driving environment information acquired by the autonomous sensing devices using the communication protocol selected in step S 304, and thereafter ends the routine. Note that, in step S 315, the communication ECU 51 may perform communication with each vehicle 5 using a communication carrier other than the current communication carrier.Further, when the flow advances from step S 312 to step S 316, the communication ECU 51 determines the communication failure level with respect to the target lane as "0". Here, communication disturbance level 0 means that the target lane is out of the communication service area, for example.In subsequent step S 317, the communication ECU 51 instructs each vehicle 5 on the target lane to perform the automated driving mainly on the basis of the driving environment information acquired by the autonomous sensing devices using the line-switched communication protocol, and thereafter ends the routine. Note that, in step S 317, the communication ECU 51 may perform communication with each vehicle 5 using a communication carrier other than the current communication carrier.Next, the failure countermeasure control in a failure of the vehicle will be described with reference to a flowchart of a failure countermeasure control routine illustrated in FIG. 11. This routine is repeatedly executed in the communication ECU 51, for example, at every predetermined time.At the start of the routine, the communication ECU 51 confirms the vehicle information transmitted from each vehicle 5 in step S 401.In subsequent step S 402, the communication ECU 51 checks whether or not there is a vehicle 5 that has transmitted a failure code to the control server 50.Further, when it is determined in step S 402 that there is no vehicle 5 that has transmitted a failure code (step S 402: NO), the communication ECU 51 ends the routine as it is.On the other hand, when it is determined in step S 402 that there is a vehicle 5 that has transmitted a failure code (step S 402: YES), the communication ECU 51 causes the flow to proceed to step S 403.In step S 403, the communication ECU 51 terminates the remote driving control of the corresponding vehicle 5, and instructs the corresponding vehicle 5 to perform an emergency stop.In subsequent step S 404, the communication ECU 51 instructs the in-vehicle travel controller 70 to end the remote control operation, and thereafter shifts to the processing for ending the remote control operation.Further, in step S 405, the communication ECU 51 supplies vehicle abnormality information to other vehicles, dealers, and the like located around the vehicle 5, and thereafter ends the routine.According to such an embodiment, the driving control system 1 includes: the communication ECU 22 that is disposed in the vehicle 5 and performs communication with the external environment by selectively using packet-switched communication or circuit-switched communication; the communication ECU 51 that is disposed in the control server 50 and performs communication with the external environment by selectively using the packet-switched communication or circuit-switched communication; the autonomous sensing devices (11 to 14) that are disposed in the vehicle 5 and sense the driving environment information; the information recognition ECU 52 that is disposed in the control server 50 and senses the driving environment information based on information sensed using the packet-switched communication; the driving ECU 21 that is disposed in the vehicle 5 and performs the autonomous driving control of the vehicles 5 based on the driving environment information; and the driving ECU 53 that is disposed in the control server 50 and performs the remote driving control based on the driving environment information of the vehicle 5.Further, when the communication ECU 51 detects a decrease in the response rate in communication with the vehicle 5 or a communication abnormality in performing remote driving control using the packet switched communication, the communication ECU 51 instructs the vehicle 5 to switch from the remote driving control to the autonomous driving control using the circuit switched communication. Thus, a balance can be established between ensuring comfort and ensuring safety by the travel control of the travel control system 1.That is, when the communication ECU 51 detects a decrease in the response rate in communication with the vehicle 5 or a decrease in communication reliability (communication abnormality) in performing remote driving control using the packet-switched communication, the communication ECU 51 instructs the vehicle 5 to change to the autonomous driving control using the circuit-switched communication.At this time, the circuit-switched communication enables stable communication with a smaller amount of data in an emergency or a disaster as compared with the packet-switched communication. Thus, even if a failure occurs in the packet-switched communication, the communication ECU 51 can give the vehicle 5 the command to change from the remote driving control to the autonomous control accurately and quickly.Thus, it is possible to switch from the remote driving control to the autonomous driving control and continue the driving control before it becomes difficult to maintain stable remote driving control. Thus, a high degree of safety and comfort can be ensured.In this case, the vehicle 5, the control server 50, and the external travel controller 70 respectively use the individual transceivers 19, 55, and 73 to ensure redundancy by multiplexing the communication protocols. Thus, even if the packet-switched communication fails, it is possible to ensure the communication for the facilities with a simple configuration to be able to give necessary notifications of the circuit-switched communication.Further, when a decrease in communication response rate is detected as communication failure, the communication ECU 51 continues packet-switched communication, thus maintaining transmission and reception of the travel environment information.Thus, the driving ECU 21 performs the autonomous driving control based on the driving environment information in which the driving environment information received from the control server 50 is added to the driving environment information acquired by the autonomous sensing devices ( 11 to 14) or the like. Thus, the autonomous driving control can be realized with a high degree of safety using the driving environment information for a wider range than the driving environment information acquired by the autonomous sensing devices ( 11 to 14) alone.Further, when a decrease in communication reliability of the packet-switched communication (communication abnormality) is detected as a communication failure, the driving ECU 21 enables the vehicle 5 to perform emergency stop at a safe location by the autonomous driving control based on the driving environment information acquired by the autonomous sensing devices ( 11 to 14) or the like. Thus, it is possible to ensure a high degree of safety without continuing excessive travel control.Further, the communication ECU 51 evaluates the communication reliability for each lane in the control area. Even if there is no abnormality in packet-switched communication even between the vehicle 5 and the control server 50, when a communication abnormality occurs with respect to the lane in which the vehicle 5 is traveling, the communication ECU 51 causes the stage of traveling control of the vehicle 5 to be gradually deactivated according to the communication disturbance level.Thus, in the case of communication abnormality, a comprehensive countermeasure against the failure can be taken for each in-lane vehicle 5, and a higher degree of safety in the travel control can be realized.Here, in the present embodiment, the image recognition ECU 11 d, the positioning ECU 20, the travel ECU 21, the communication ECU 22, the communication ECU 51, the information recognition ECU 52, the travel ECU 53, the communication ECU 71, and the travel ECU 72 include, for example, a known microcomputer and its peripheral devices.The microcomputer includes, for example, a CPU, a RAM, a ROM, and a nonvolatile memory. In the ROM, a program to be executed by the CPU and fixed data such as data tables are stored in advance. Note that all or part of the functions of the processor may be realized by a logic circuit or an analog circuit. Further, the processing of the various programs may be realized by electronic circuits such as an FPGA.It should be noted that the invention is by no means limited to the above-described embodiments. It will be understood that modifications and changes may be made, and that the modifications and changes are also within the scope of the invention.References included in the specificationThis list of documents cited by the applicant has been produced in an automated manner and is only included for the better information of the reader. The list is not part of the German patent application or utility model application. The DPMA does not take any adhesion for any faults or omissions.Patent Literature citedWO 2017 / 179209 A1

[0004]

Claims

A driving control system, comprising: a first communication controller configured to be disposed in a vehicle and perform communication with the external environment by selectively using packet-switched communication or circuit-switched communication; a second communication controller configured to be disposed in a control server and perform communication with the external environment by selectively using the packet-switched communication or circuit-switched communication; a first driving environment information detector configured to be disposed in the vehicle and detect first driving environment information using an autonomous sensor; a second driving environment information detector configured to be disposed in the control server and detect second driving environment information based on information detected using the packet-switched communication; a first driving controller configured to be disposed in the vehicle and perform autonomous driving control of the vehicle based on the first driving environment information; and a second driving controller configured to be disposed in the control server and perform remote driving control of the vehicle based on the second driving environment information, wherein the second driving controller is configured to, when the second driving controller detects a decrease in response rate in communication with the vehicle or a communication abnormality in performing remote driving control using the packet switched communication, command the vehicle to change from the remote driving control to the autonomous driving control using the circuit switched communication.The driving control system according to claim 1, - wherein the first communication controller is configured to receive, from the control server, the second driving environment information covering a larger area than the first driving environment information, - wherein the first driving controller is configured to perform the autonomous driving control based on the first driving environment information to which the second driving environment information is added.The driving control system according to claim 2, - wherein the second communication controller is configured to, when a decrease in the communication response rate is detected, continue transmitting the second driving environment information using the packet-switched communication, - wherein the first driving controller is configured to, when a decrease in the communication response rate is detected, perform the autonomous driving control based on the first driving environment information to which the second driving environment information is added.The driving control system according to claim 2, wherein the first driving controller is configured to, when a communication abnormality is detected, allow the vehicle to perform an emergency stop by the autonomous driving controller based on the first driving environment information.The driving control system according to any one of claims 1 to 4, further comprising: a third communication controller configured to be disposed in an out-of-vehicle driving control device configured to perform driving control of the vehicle by the control server and perform communication with the external environment by selectively using packet switched communication or circuit switched communication; a third travel controller configured to be disposed in the off-board travel controller and to perform the remote travel control of the vehicle based on the second travel environment information received from the control server using the packet-switched communication, wherein the second communication controller is configured to, when the second communication controller detects a decrease in the response rate in the communication with the vehicle or a communication abnormality in the performance of the remote travel control using the packet-switched communication, command the off-board travel controller to end the remote travel control using the circuit-switched communication.

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