Server control system for automatic driving of vehicle

Abstract

[Problem] To improve automatic driving of a vehicle under server control by a server device. [Solution] In this server control system, a server device periodically transmits travel control information to a traveling vehicle through a base station that wirelessly communicates with the vehicle. A vehicle communication device of the vehicle executes switching control for switching a connection destination from a first base station to a second base station while the vehicle is traveling. A server control unit generates switching prohibition information for prohibiting switching control of a connection destination by the vehicle communication device, and transmits the switching prohibition information to the vehicle together with travel control information for controlling, by the server, travel of the vehicle by automatic driving. Upon receiving the switching prohibition information, the vehicle causes the vehicle communication device to execute switching control of the connection destination, and prohibits subsequent switching control of the connection destination.

Description

Server Control System for Automatic Driving of Vehicles

[0001] This application mainly discloses a server control system for automatic driving of vehicles.

[0002] In an autonomous driving vehicle, there is a vehicle communication control unit that autonomously controls driving based on the detection results of the vehicle's autonomous sensors. In contrast, Patent Documents 1 to 3 disclose a server device that can communicate with a vehicle. Using such a server device, it is conceivable to transmit driving control information for autonomous driving from the server device to the vehicle and execute the automatic driving of the vehicle under server control. In this case, since the vehicle moves by driving, a base station wirelessly connected to the vehicle is used for communication between the vehicle and the server device.

[0003] Japanese Patent Application Laid-Open No. 2014-044639, Japanese Patent Application Laid-Open No. 2008-283700, Japanese Patent Application Laid-Open No. 2021-010045

[0004] By the way, when the communication between the vehicle and the base station deteriorates in radio wave conditions, the communication is handed over from the first base station to the second base station regardless of the communication state between the vehicle and the server device. As a result, even if the vehicle moves by driving, it becomes possible to continue communicating with the server device.

[0005] However, when attempting to control the automatic driving of a vehicle by a server device, the server device is required to continuously transmit driving control information for the automatic driving of the vehicle to the vehicle at relatively short intervals. Also, the server device needs to continuously receive information on the latest driving environment of the vehicle from the vehicle at the same cycle.

[0006] On the other hand, in areas where the zones of the first and second base stations overlap, for example, a vehicle may be relatively far from either base station. In this case, both communication between the vehicle and the first base station, and communication between the vehicle and the second base station, will have reduced signal strength and quality compared to when the vehicle is close to the base station. Furthermore, the presence of obstacles may also make communication unstable. Under these conditions of reduced or unstable signal conditions, the connection for communication between the vehicle and the base station may be temporarily interrupted when switching from the first to the second base station, or the connection destination may be repeatedly switched between these base stations. At the time of switching, for example, information from the server equipment already acquired by the first base station needs to be transferred from the first base station to the second base station via the base station communication network, and then transmitted from the second base station to the vehicle. If such situations occur frequently or continuously, even for short periods, the load on the base stations and the base station communication network will increase. If the load on the base stations and the base station communication network increases drastically, the likelihood of information delays or loss on the base station side increases. For vehicles operating autonomously under the control of a server device, delays or omissions in the driving control information periodically received from the server device are undesirable.

[0007] Thus, improvements are needed for automated vehicle operation under the control of a server device.

[0008] A server control system for autonomous driving of a vehicle according to one embodiment of the present invention is a server control system for autonomous driving of a vehicle which periodically transmits driving control information from a server control unit of a server device to the vehicle via a base station that communicates wirelessly with the vehicle communication device of the moving vehicle, wherein the vehicle communication device performs switching control to switch the connection destination from a first base station to a second base station while the vehicle is in motion, the server control unit generates switching prohibition information to prohibit the vehicle's vehicle communication device from performing the switching control of the connection destination and transmits it to the vehicle along with the driving control information for server control of the vehicle's autonomous driving, and the vehicle has a vehicle communication control unit which, when the vehicle communication device receives the switching prohibition information, causes the vehicle communication device to perform the switching control of the connection destination and sets a prohibition on the switching control of the connection destination for the vehicle communication device.

[0009] In one embodiment of the present invention, the server control unit of the server device periodically transmits driving control information to the vehicle. The server control unit also generates switching prohibition information to prohibit the vehicle's vehicle communication device from switching the connection destination and transmits it to the vehicle along with the driving control information. When the vehicle communication device receives the switching prohibition information, the vehicle communication control unit of the vehicle, which is driving under the server control of the server device, executes the connection destination switching control using the vehicle communication device. The vehicle communication control unit also sets a prohibition on the connection destination switching control for the vehicle communication device.

[0010] As a result, the vehicle's communication device can, upon receiving information prohibiting switching the connection destination, switch the connection destination from the first base station to the second base station while the vehicle is in motion, and maintain that switched state. After the switch is executed, the vehicle communication device does not perform connection destination switching control even if the vehicle moves by driving. Moreover, the communication quality between the vehicle communication device and the second base station is expected to improve as the vehicle moves by driving. Therefore, the information transmitted by the server device to the vehicle is maintained in a state where it can be received by the vehicle through the second base station, and is less likely to be delayed or lost on the base station side. Furthermore, the moving vehicle receives driving control information along with the connection destination switching prohibition information described above. Therefore, even during the period when connection destination switching control is prohibited, the moving vehicle is expected to continue automatic driving under the server control of the server device in accordance with the driving control information received along with the switching prohibition information. The vehicle is expected to continue automatic driving under the server control of the server device during the period when connection destination switching control is prohibited, and before and after that period. In one embodiment of the present invention, the automatic driving of the vehicle under the server control of the server device is expected to be improved.

[0011] Figure 1 is a configuration diagram of a server control system for automated vehicle driving according to the first embodiment of the present invention. Figure 2 is an explanatory diagram of an example of the control system of the control vehicle in Figure 1. Figure 3 is a configuration diagram of the control server device in Figure 1. Figure 4 is a timing chart showing the overall flow of individual control in the server control system for automated vehicle driving in Figure 1. Figure 5 is an explanatory diagram of an example of the configuration of a vehicle communication device in the control vehicle in Figure 2. Figure 6 is an explanatory diagram of an example of handover control by the vehicle communication device in Figure 5. Figure 7 is an explanatory diagram of another example of handover control by the vehicle communication device in Figure 5. Figure 8 is a flowchart of an example of base station switching control by the server control unit in Figure 3. Figure 9 is a flowchart of an example of individual control in the first embodiment by the server control unit in Figure 3. Figure 10 is an explanatory diagram of an ST chart for determining the possibility of interference. Figure 11 is a flowchart of an example of handover control by the external communication control device in Figure 2. Figure 12 is a timing chart showing the overall flow of individual control and handover control in this embodiment. Figure 13 is an explanatory diagram showing the control vehicle in Figure 1 traveling towards a lane change point. Figure 14 is a flowchart of an example of individual control by the server control unit according to the first embodiment of the present invention.

[0012] Hereinafter, embodiments of the present invention will be described with reference to the drawings in the following order. Each embodiment will be described after an overview of the embodiment.Specific examples of each embodiment will be described in order: overview, configuration example, overview of control, and control example.The following descriptions of embodiments and drawings are examples of the invention disclosed in this application and do not limit the invention disclosed in this application.

[0013] [First Embodiment] (Overview) When a server device controls the driving of a vehicle, the server device and the vehicle exchange information through a base station that communicates wirelessly with the vehicle's communication device while it is in motion. For example, the server control unit of the server device periodically transmits driving control information to the vehicle through a base station that communicates wirelessly with the vehicle's communication device. In addition, the vehicle's communication device needs to switch the base station it is connected to in order to ensure wireless communication quality while the vehicle is in motion. The vehicle communication device needs to perform switching control while the vehicle is in motion, for example, to switch the connection destination from the first base station to the second base station. This base station switching is performed regardless of the communication status between the server device and the vehicle, based on the vehicle communication device's judgment of communication quality. Depending on the timing of the base station switching, it is possible that the driving control information transmitted by the server device to the vehicle may not be received by the vehicle's communication device at the appropriate time. For this reason, the server control unit generates switching prohibition information to prohibit the vehicle's communication device from performing switching control of the connection destination. The server control unit transmits driving control information and switching prohibition information to the vehicle for server control of the vehicle's autonomous driving. When the vehicle's communication control unit receives switching prohibition information from the vehicle's communication device, it instructs the vehicle's communication device to perform switching control of the connection destination and sets a prohibition period for switching control of the connection destination for the vehicle's communication device. This makes the timing of base station switching by the vehicle's communication device controllable by the server control unit. In addition, the server control unit may generate switching prohibition information and transmit it to the vehicle equipped with the vehicle's communication device if the quality of wireless communication between the vehicle and the base station meets the switching conditions that allow the vehicle's communication device to make a switching decision earlier. This allows the server control unit to determine the wireless quality of the base station earlier than the vehicle's communication device and set the switching prohibition.

[0014] (Configuration Example) Figure 1 is a configuration diagram of a server control system 1 for the automatic driving of a vehicle according to the first embodiment of the present invention. The server control system 1 in Figure 1 comprises a control vehicle 2 and a control server device 3. The server control system 1 of this embodiment allows the control vehicle 1 to perform automatic driving under the server control of the control server device 3.

[0015] Control vehicle 2 is an example of a vehicle. Vehicles include, for example, automobiles, buses, and trucks. Here, control vehicle 2 refers to a vehicle that is operating under the server control of the control server device 3. In addition to automatic driving under server control, control vehicle 2 may also be capable of manual driving by a driver, autonomous automatic driving based on the detection results of autonomous sensors, etc. Autonomous automatic driving may be fully automatic driving, such as levels 4 and 5 of the automatic driving level, or partially automatic driving, such as levels 1 and 2.

[0016] The control server device 3 receives vehicle information, including the locations of multiple vehicles such as the control vehicle 2, and periodically generates individual control information as driving control information and transmits it to the control vehicle 2. This enables the control vehicle 2 to continuously drive automatically under server control. A carrier communication system with multiple base stations is used for communication between the control server device 3 and the control vehicle 2 and other vehicles. The multiple base stations are arranged along the road, for example, as shown in Figure 1. Each base station can communicate with vehicles within its respective zone. In Figure 1, the first base station 4 can communicate with vehicles such as the control vehicle 2 in the first zone, indicated by the dashed circle around it, and with other vehicles 103. The second base station 5 can communicate with vehicles not shown in the second zone, indicated by the dashed circle around it. In the carrier communication system, the multiple base stations are connected to a carrier communication network 6, which is a base station communication network. The multiple base stations can send and receive information from each other through the carrier communication network 6.

[0017] In Figure 1, the control server device 3 is connected to the carrier communication network 6. The control server device 3 can send and receive information with vehicles with low latency through the carrier communication network 6 and the base station. Also in Figure 1, the control vehicle 2 is traveling on the merging road 102. The other vehicle 103 is traveling on the main road 101. The merging road 102 is connected to the main road 101. In this case, the control vehicle 2 will travel on the merging road 102 to the merging point and then travel on the main road 101. The control server device 3 will also periodically transmit individual control information to the control vehicle 2 via the first base station 4, which is capable of wireless communication with the moving control vehicle 2.

[0018] Figure 2 is an explanatory diagram of an example of the control system 10 of the control vehicle 2 shown in Figure 1. The control system 10 of the control vehicle 2 in Figure 2 has a vehicle network 19 and a plurality of control devices connected thereto. As examples of the plurality of control devices, Figure 2 shows a sensor control device 11, a driving control device 12, a drive control device 13, a steering control device 14, a braking control device 15, and an external communication control device 16. The control system 10 of the control vehicle 2 may also include other control devices, such as an operation control device. The operation control device is connected to operating members that the driver operates when manually driving, such as a steering wheel and pedals. In addition, each of the control devices shown in Figure 2 may be divided into multiple units and connected to the vehicle network 19.

[0019] The vehicle network 19 may be a vehicle-specific network such as a CAN (Controller Area Network), a LIN (Local Interconnect Network), or a vehicle-specific communication network. Alternatively, the vehicle network 19 may include a general communication network such as IEEE (Institute of Electrical and Electronics Engineers) 802.3. By using such a vehicle network 19, the control device installed in the control vehicle 2 can input and output information to and from other control devices through the vehicle network 19.

[0020] The sensor control device 11 controls the operation of various autonomous sensors installed on the control vehicle 2 and outputs the detected values ​​of the autonomous sensors or processed information obtained by processing the detected values ​​to other control devices via the vehicle network 19. Figure 2 shows examples of multiple autonomous sensors connected to the sensor control device 11, including a GNSS (Global Navigation Satellite System) receiver 21, an external camera 22, a LiDAR (Light Detection and Ranging) 23, a laser device 24, and an acceleration sensor 25. In addition to these, the sensor control device 11 may also be connected to a vehicle speed sensor to detect the speed of the control vehicle 2, a steering sensor to detect the steering angle of the steering wheels of the control vehicle 2, and so on.

[0021] The GNSS receiver 21 generates position and time information for the control vehicle 2 by receiving radio waves from multiple GNSS satellites (not shown).

[0022] The external camera 22 captures images of the driving environment around the control vehicle 2 as it travels on roads or other surfaces. The external camera 22 may be a monocular camera, a compound camera, or a 360-degree camera. It is desirable that the external camera 22 be able to capture images of at least the front of the moving control vehicle 2.

[0023] LiDAR23 scans the area around the vehicle with an optical laser and generates spatial information about the area surrounding the vehicle.

[0024] The laser device 24 emits laser light and detects the area around the vehicle by the reflected light. The external camera 22, LiDAR 23, and laser device 24 can then detect other vehicles 103, for example, in the vicinity of the vehicle. Fully automated control vehicles 2 may be equipped with all of the external camera 22, LiDAR 23, and laser device 24. Partially automated control vehicles 2 may be equipped with only some of the external camera 22, LiDAR 23, and laser device 24.

[0025] The acceleration sensor 25 detects the acceleration of the control vehicle 2. By using a sensor that detects axial acceleration as the acceleration sensor 25, the sensor control device 11 can generate information on the angular acceleration of the control vehicle 2 in the yaw, pitch, and roll directions. Alternatively, the sensor control device 11 may generate information on the velocity of the control vehicle 2 by integrating the acceleration of the acceleration sensor 25 over time.

[0026] The vehicle communication device 27, installed in the control vehicle 2, is connected to the external communication control device 16. The vehicle communication device 27 establishes a wireless communication path with a base station that can communicate with it. This connects the vehicle communication device 27 to the base station. The external communication control device 16 controls the operation of the vehicle communication device 27 and performs the sending and receiving of information with the control server device 3 through the vehicle communication device 27 and the base station. For example, the external communication control device 16 outputs information received by the vehicle communication device 27 from the control server device 3 or the base station to other control devices via the vehicle network 19. The external communication control device 16 transmits information input from other control devices via the vehicle network 19 to the control server device 3 via the vehicle communication device 27 and the base station.

[0027] The drive control device 13 includes, for example, an engine that generates driving force using gasoline or hydrogen as fuel, a motor that generates driving force using electricity, a transmission, or a drive system that combines these, which is installed in the control vehicle 2. The drive control device 13 controls the operation of the drive system based on control values ​​acquired through the vehicle network 19.

[0028] The steering control device 14 is connected to, for example, a steering device installed in the control vehicle 2. The steering control device 14 controls the operation of the steering device based on control values ​​obtained through the vehicle network 19.

[0029] The braking control device 15 is connected to the brake device installed in the control vehicle 2. The braking control device 15 controls the operation of the brake device based on control values ​​acquired through the vehicle network 19.

[0030] The driving control device 12 controls the driving of the control vehicle 2. The driving control device 12 may have, for example, a vehicle CPU (not shown) and a vehicle memory. Programs and data are stored in the vehicle memory. High-precision map data 26 may be stored in the vehicle memory. The vehicle CPU reads and executes the program in the vehicle memory. In this way, the driving control device 12 controls the driving of the control vehicle 2. When controlling driving in manual driving mode, the driving control device 12 may periodically generate control values ​​according to the amount of steering or pedal operation performed by the driver. In this case, the driving control device 12 may adjust the control values ​​by considering information on the vehicle's driving state and information on the vehicle's surroundings in order to assist the driver. In the case of autonomous automatic driving, the driving control device 12 acquires information on the vehicle's driving state and information on the vehicle's surroundings from the sensor control device 11 and periodically generates control values ​​according to that information. In this case, the driving control device 12 may, for example, determine the condition of the road and lane on which the vehicle is traveling based on the latest position of the vehicle in high-precision map data 26, and generate control values ​​for steering and acceleration / deceleration. When the driving control device 12 is driving automatically under the control of the control server device 3, it acquires individual control information from the control server device 3 and information on the vehicle's driving state and surroundings from the sensor control device 11, and periodically generates control values ​​according to this information. In this case, the driving control device 12 may generate control values ​​such that, if there are no obstacles based on the information surrounding the vehicle, the vehicle will drive according to the individual control information from the control server device 3. The driving control device 12 may switch between the various driving controls described above depending on the driving state and driving environment of the control vehicle 2, which can be determined based on the individual control information, the vehicle's detection information, or the driver's operation. A control vehicle 2 equipped with such a driving control device 12 can continuously drive under the server control of the control server device 3 by automatic driving using individual control information.

[0031] Figure 3 is a configuration diagram of the control server device 3 shown in Figure 1. The control server device 3 communicates with the control vehicle 2 traveling on the road to control or assist the movement of the control vehicle 2. The control server device 3 in Figure 3 includes a server communication device 31, a server GNSS receiver 32, a server DB (database) 33, a server memory 34, a server CPU (Central Processing Unit) 35, and a server bus 39 to which these are connected.

[0032] The server communication device 31 is connected to the carrier communication network 6. The server communication device 31 periodically sends and receives vehicle information, including at least the driving position of each vehicle, and individual control information, with the multiple vehicle communication devices 27 installed in the multiple control vehicles 2. As a result, the server communication device 31 can receive information regarding the latest driving status of each of the multiple control vehicles 2.

[0033] The server GNSS receiver 32 receives radio waves from GNSS satellites and generates position and time information for the control server device 3. This allows the time on the control server device 3 to synchronize with the time on multiple control vehicles 2 with high accuracy.

[0034] The server DB 33 is a database that stores and records information on each of the multiple control vehicles 2 that the control server device 3 has under its control. The server DB 33 may record, for example, a vehicle location DB (database) 43, which will be described later.

[0035] The server memory 34 stores data such as programs executed by the server CPU 35 and setting values. Server map data may also be stored in the server memory 34. Here, the server map data is for roads that autonomous vehicles such as the control vehicle 2 can travel on, and preferably contains information equivalent to the high-precision map data 26 used by the control vehicle 2. Generally, the server map data should be high-precision map data that includes information on each lane of the road, intersection information, etc.

[0036] The server CPU 35 reads and executes the program stored in the server memory 34. This enables the control server device 3 to have a server control unit 36 ​​that controls its operation. The server control unit 36 ​​includes functions such as a pre-processing unit 41 and a control control unit 42, as will be described later.

[0037] Figure 4 is a timing chart showing the overall flow of individual control in the server control system 1 for the automated driving of the vehicle shown in Figure 1. Time flows from top to bottom. Due to the limitations of the drawing, only one control vehicle 2 is shown in Figure 4. The control server device 3 in Figure 4 has a pre-processing unit 41, a control control unit 42, and a vehicle position DB 43.

[0038] The control device 12 of the control vehicle 2 acquires its own vehicle information in step ST1 and transmits its vehicle information to the control server device 3 in step ST2. The vehicle information includes the latest location, time, speed, control status, and other information of the control vehicle 2. In this embodiment, the vehicle information may also include information on the communication quality with one or more base stations to which the vehicle communication device 27 can connect. The vehicle information of the control vehicle 2 in Figure 1 is transmitted to the control server device 3 through the first base station 4 and the carrier communication network 6 to which the vehicle communication device 27 is connected. When the server communication device 31 receives new vehicle information, the pre-processing unit 41 of the control server device 3 records it in the vehicle position DB 43 in step ST3. The vehicle position DB 43 stores and records vehicle information such as the location of multiple control vehicles 2, classified for each vehicle. The vehicle position DB 43 may also record vehicle information such as the location of other vehicles 103 other than the control vehicle 2. As a result, the vehicle position DB 43 accumulates information on multiple vehicles traveling on the same road as the control vehicle 2. The control control unit 42 of the control server device 3 performs individual control in step ST4 at predetermined control cycles. The control control unit 42 generates individual control information that the control vehicle 2 will use for driving control and transmits it to the control vehicle 2 in step ST5. The driving control device 12 of the control vehicle 2 performs vehicle driving control to control its own automatic driving in step ST6 at predetermined control cycles. When the vehicle communication device 27 receives new individual control information, the driving control device 12 generates control values ​​using the individual control information from the control server device 3, information on the vehicle's driving status and information on its surroundings from the sensor control device 11, and outputs them to the drive control device 13, steering control device 14, and braking control device 15. As a result, the control vehicle 2 can drive automatically under the server control of the control server device 3. The control server device 3 and the control vehicle 2 synchronously and periodically repeat the series of controls shown in Figure 4. As a result, the control vehicle 2 can continue to operate automatically under the server control of the control server device 3.

[0039] Figure 5 is an explanatory diagram illustrating the configuration of an example of the vehicle communication device 27 of the control vehicle 2 shown in Figure 2. The vehicle communication device 27 of the control vehicle 2 shown in Figure 5 includes a high-frequency antenna 51, a multiplexer 52, a radio frequency circuit (RF) 53, and a baseband circuit (BB) 68. The radio frequency circuit 53 includes a high-frequency receiving amplifier 54, a receiving mixer 55, a received signal detector 58, a receiving amplifier 56, an AD converter 57, a logic circuit 59, an oscillator 60, a VCO / PLL circuit 61, a DA converter 62, a transmitting amplifier 63, a transmitting mixer 64, and a high-frequency power amplifier 65. The baseband circuit 68 includes a MAC (Medium Access Control) circuit 66 and a host communicator 67.

[0040] The high-frequency antenna 51 detects the high-frequency radio waves of the base station. The multiplexer 52 outputs the high-frequency received radio wave signal detected by the high-frequency antenna 51. The high-frequency receiving amplifier 54 amplifies the received radio wave signal with low noise. The receiving mixer 55 mixes the amplified received radio wave signal with the local frequency of the VCO / PLL circuit 61 based on the oscillator 60 to generate an intermediate frequency signal or a low-frequency signal. The receiving signal detector 58 generates a radio quality evaluation value based on the output signal of the receiving mixer 55. The evaluation value for wireless quality may be, for example, RSSI (Received Signal Strength Indicator), RSRP (Reference Signal Received Power), RSRQ (Reference Signal Received Quality), or SINR (Signal to Interference plus Noise Ratio). The receiving amplifier 56 amplifies the output signal of the receiving mixer 55 with filtering according to the evaluation value of wireless quality from the received signal detector 58. The AD converter 57 converts the received signal amplified by the receiving amplifier 56 into digital received data. The host communicator 67 of the baseband circuit 68 outputs the received data acquired via the MAC circuit 66 to the external communication control device 16 of the control vehicle 2. The received data is then output to each control device via the external communication control device 16 and the vehicle network 19.

[0041] The host communicator 67 of the baseband circuit 68 acquires transmission data from the external communication control device 16 of the control vehicle 2 and outputs it to the radio frequency circuit 53. The DA converter 62 converts the transmission data into a transmission signal. The transmission amplifier 63 amplifies the transmission signal. The transmission mixer 64 mixes the transmission signal with the local frequency of the VCO / PLL circuit 61 based on the oscillator 60 to generate a high-frequency transmission signal. The high-frequency power amplifier 65 amplifies the transmission signal. The multiplexer 52 outputs radio waves based on the amplified transmission signal from the high-frequency antenna 51.

[0042] The MAC circuit 66 then performs control for communication with the base station. The MAC circuit 66 performs tasks such as allocating radio resources, data mapping, and retransmission control. The MAC circuit 66 also searches for a base station that can communicate and, if there is a base station that can communicate better than the currently connected base station, performs handover control to switch to the base station. As a result, the vehicle communication device 27 is connected to a communication-enabled base station and can send and receive information.

[0043] Figure 6 is an explanatory diagram of an example of handover control by the vehicle communication device 27 shown in Figure 5. The horizontal axis in Figure 6 represents time, and the vertical axis represents the RSSI value. In Figure 6, the control vehicle 2 is traveling along the road from a position near the first base station 4 toward the second base station 5, as shown in Figure 1. Therefore, the RSSI value, which is an evaluation value of the radio quality of the radio waves received by the first base station 4 detected by the vehicle communication device 27, decreases over time. Conversely, the RSSI value of the second base station 5 increases over time. The MAC circuit 66 of the vehicle communication device 27 evaluates the RSSI values ​​of the first base station 4 and the second base station 5, which are available for communication, at each time point. When the RSSI value of the connected first base station 4 falls below the RSSI value of the available second base station 5, the MAC circuit 66 performs handover control to switch base stations. In the case of Figure 6, the MAC circuit 66 of the vehicle communication device 27 will perform handover control at time t1 to switch the base station from the first base station 4 to the second base station 5. In this case, the RSSI value at which the RSSI value of the first base station 4 matches the RSSI value of the second base station 5, which is capable of communication, will be the connection switching control value.

[0044] FIG. 7 is an explanatory diagram of another example of handover control by the vehicle communication device 27 in FIG. 5. The horizontal axis in FIG. 7 represents frequency, and the vertical axis represents signal strength value. In FIG. 7, a signal waveform by OFDM (Orthogonal Frequency Division Multiplexing) is shown. In FIG. 7, as shown in FIG. 1, the control vehicle 2 is traveling on the road so as to move away from a position near the first base station 4. Therefore, the signal strength value, which is an evaluation value of the radio quality of the received radio wave of the first base station 4 detected in the vehicle communication device 27, decreases with the passage of time from the solid line signal waveform to the broken line signal waveform in the figure. Then, the MAC circuit 66 of the vehicle communication device 27 evaluates the signal strength value of the connected first base station 4 at each moment. When the signal strength value of the connected base station becomes less than a predetermined connection switching threshold value, the MAC circuit 66 executes handover control for switching the base station to another base station. In the case of FIG. 7, when the signal strength value of the first base station 4 becomes below the connection switching threshold value, the MAC circuit 66 of the vehicle communication device 27 executes handover control for switching the base station from the first base station 4 to the second base station 5.

[0045] By these handover controls, the vehicle communication device 27 of the control vehicle 2 can switch the connected base station according to the movement of the control vehicle 2. The vehicle communication device 27 can continue to transmit and receive information to and from the control server device 3 even while the control vehicle 2 is moving. In FIG. 4, in the third control cycle, the vehicle communication device 27 executes handover control for switching the connection destination from the first base station 4 to the second base station 5.

[0046] However, when attempting to control the automatic driving of the vehicle by the control server device 3, as shown in FIG. 4, the control server device 3 is required to continuously transmit the individual control information for the automatic driving of the vehicle to the control vehicle 2 at relatively short intervals. Also, the control server device 3 needs to continuously receive the latest vehicle information and the like from the control vehicle 2 and the like at the same cycle.

[0047] On the other hand, for example, as shown in FIG. 1, in an area where the zone of the first base station 4 and the zone of the second base station 5 partially overlap, the control vehicle 2 is relatively far from both base stations. In this case, both the communication between the control vehicle 2 and the first base station 4 and the communication between the control vehicle 2 and the second base station 5 have a lower radio wave intensity and quality as shown in FIG. 6 compared to the case where the vehicle is near the base station. If there are obstacles or the like on the radio path, the communication may become unstable. And in such a situation where the radio wave state deteriorates or becomes unstable, the connection for communication between the control vehicle 2 and the base station may experience a temporary disconnection when switching from the first base station 4 to the second base station 5, or the switching of the connection destination may be repeated between those base stations. Also, at the switching timing, for example, the individual control information of the control server device 3 that has already been acquired by the first base station 4 needs to be transferred from the first base station 4 to the second base station 5 through the carrier communication network 6 and then transmitted from the second base station 5 to the control vehicle 2. If such situations occur frequently or continuously even for a short period, the load on the base station and the carrier communication network 6 increases. When the load on the base station and the carrier communication network 6 increases extremely, the possibility of information delay and loss on the base station side increases. For the control vehicle 2 running under the automatic driving controlled by the control server device 3, it is not desirable for the individual control information periodically received from the control server device 3 to be delayed or missing. In the case of FIG. 4, the individual control information in the third control cycle may be received by the control vehicle 2 with a delay. In the communication in the third control cycle of FIG. 4, these situations may occur.

[0048] Thus, improvement is required for the automatic driving of vehicles under the server control of the control server device 3.

[0049] (Overview of Control) In this embodiment, the control server device 3 forcibly executes handover control before the wireless quality of the connected base station deteriorates to the extent that the vehicle communication device 27 can execute handover control on its own judgment. The control server device 3 also transmits switching prohibition information to the control vehicle 2, along with individual control information, to temporarily prohibit handover control by the vehicle communication device 27 immediately after the execution of the forced handover control. Such timing control of handover is important when the vehicle merges or changes lanes, for example. The server control unit may generate switching prohibition information when the quality of wireless communication between the vehicle communication device 27 and the base station satisfies switching conditions that allow the vehicle communication device to make a switching decision earlier, and the vehicle is traveling towards a road or lane merging point or lane change point. The server control unit may also transmit information on the travel section up to the zone boundary of the first base station as travel control information transmitted along with the switching prohibition information. Furthermore, the server control unit may generate multiple sets of position and time information for the vehicle's passage within the driving section as driving control information to be transmitted along with the switching prohibition information.

[0050] (Control Example) Figure 8 is a flowchart of an example of base station switching control by the server control unit 36 ​​of Figure 3. The server control unit 36 ​​of the control server device 3 periodically executes the base station switching control shown in Figure 8, separately from the processing for sending and receiving information with the control vehicle 2 as described above. The period of the base station switching control in Figure 8 may be the same as the control period. In addition, the server control unit 36 ​​may execute the base station switching control shown in Figure 8 if it receives vehicle information from the control vehicle 2, for example, which includes information on radio quality.

[0051] In step ST11, the server control unit 36 ​​determines whether the control vehicle 2 is traveling towards a road merging point or lane change point. The server control unit 36 ​​may map the latest location included in the vehicle information of the control vehicle 2 to the server map data to determine whether the control vehicle 2 is traveling towards a road merging point or lane change point. In this case, the server control unit 36 ​​may determine that the control vehicle 2 is traveling towards a road merging point or lane change point if, for example, the distance from the merging point or lane change point to the control vehicle 2 is less than or equal to the radius of the base station's standard zone. If the server control unit 36 ​​determines that the control vehicle 2 is traveling towards a road merging point or lane change point, it proceeds to step ST12. If the server control unit 36 ​​does not determine that the control vehicle 2 is traveling towards a road merging point or lane change point, it terminates this control.

[0052] In step ST12, the server control unit 36 ​​obtains the latest radio quality information of the control vehicle 2 related to the processing in step ST11. The vehicle information of the control vehicle 2 includes the latest radio quality information. The server control unit 36 ​​may obtain the latest radio quality information from the vehicle information of the control vehicle 2.

[0053] In step ST13, the server control unit 36 ​​determines whether the latest radio quality information from the control vehicle 2 satisfies the switching conditions by server control. Here, the switching conditions by server control should be such that the server control unit can determine the switching of the connection destination earlier than the switching conditions that the vehicle communication device 27 uses to decide to switch the connection destination on its own. For example, if RSRI values ​​are acquired, the server control unit 36 ​​may use the control switching threshold shown in Figure 6 as a reference to determine whether the switching conditions by server control are met. The control switching threshold is higher than the level at which the RSRI values ​​of the first base station 4 and the second base station 5 intersect. This allows the server control unit 36 ​​to determine the switching earlier than the vehicle communication device 27. In addition, for example, if signal strength values ​​are acquired, the server control unit 36 ​​may use the control switching threshold shown in Figure 7 as a reference to determine whether the switching conditions by server control are met. The control switching threshold is higher than the connection switching threshold that the vehicle communication device 27 uses to decide to switch the connection destination. This allows the server control unit 36 ​​to determine the switchover earlier than the vehicle communication device 27. If the server control unit 36 ​​determines that the server-controlled switchover conditions are met in any of its decisions, it proceeds to step ST14. If the server control unit 36 ​​determines that the server-controlled switchover conditions are not met in any of its decisions, it terminates this control.

[0054] In step ST14, the server control unit 36 ​​generates switching prohibition information to prohibit the control of switching the connection destination by the vehicle communication device 27 of the control vehicle 2. The server control unit 36 ​​may generate switching prohibition information that includes a period during which switching is prohibited. Here, the prohibition period may be the time it takes for the control vehicle 2 to reach the base station's zone boundary from its current location at its current speed. The server control unit 36 ​​may record the switching prohibition information in the vehicle position DB 43. After that, the server control unit 36 ​​terminates this control.

[0055] Figure 9 is a flowchart of an example of individual control in the first embodiment, performed by the server control unit 36 ​​in Figure 3. The server control unit 36 ​​of the control server device 3 repeatedly executes the individual control in Figure 9 at each control cycle in order to transmit individual control information to the control vehicle 2.

[0056] In step ST21, the server control unit 36 ​​first selects the control vehicle 2 for which individual control information is to be generated from the vehicle position DB 43.

[0057] In step ST22, the server control unit 36 ​​maps the control vehicle 2 and other items related to the processing selected in step ST21 onto the ST chart.

[0058] Figure 10 is an explanatory diagram of the ST chart used to determine the possibility of interference. The horizontal axis of Figure 10 represents the distance along the road or lane on which the control vehicle 2 involved in the processing is traveling. The vertical axis represents time. Time flows from top to bottom. The server control unit 36 ​​obtains information on the control vehicle 2 involved in the processing from the vehicle position DB 43, maps the control vehicle 2 involved in the processing to the latest position included in the vehicle information, and maps the line segment moving at the latest speed included in the vehicle information onto the ST chart. The server control unit 36 ​​also maps other vehicles 103 traveling on the road or lane on which the control vehicle 2 is traveling onto the ST chart. The position and speed of other vehicles 103 may be obtained from the information on other vehicles 103 in the vehicle position DB 43, etc. As a result, the ST chart in Figure 10 maps the control vehicle 2 and other vehicles 103 from Figure 1. The control vehicle 2 is traveling from the merging road 102 toward the main road 101. Therefore, other vehicles 103 traveling on the main road 101 are mapped from a position away from the horizontal axis of the ST chart. In contrast, the control vehicle 2 is mapped downwards from the horizontal axis of the ST chart. The dashed lines in the figure indicate the merging points. The server control unit 36 ​​can map the control vehicle 2 involved in processing and other vehicles 103 that may interfere with it onto the ST chart.

[0059] In step ST23, the server control unit 36 ​​determines the possibility of interference between the control vehicle 2 involved in processing and other vehicles 103, etc. In Figure 10, the line segment of the control vehicle 2 involved in processing and the line segment of other vehicles 103 do not intersect or come close to each other. In this case, the server control unit 36 ​​determines that there is no possibility of interference between the control vehicle 2 involved in processing and other vehicles 103, etc. In contrast, in the ST chart, if the line segment of the control vehicle 2 involved in processing and the line segment of other vehicles 103 intersect or come close to each other, the server control unit 36 ​​determines that there is a possibility of interference between the control vehicle 2 involved in processing and other vehicles 103, etc.

[0060] In step ST24, the server control unit 36 ​​determines whether or not switching prohibition information has been generated for the control vehicle 2 involved in the processing. If switching prohibition information has not been generated, the server control unit 36 ​​proceeds to step ST25. If switching prohibition information has been generated, the server control unit 36 ​​proceeds to step ST26.

[0061] In step ST25, the server control unit 36 ​​generates individual control information for control vehicle 2 for which no switching prohibition information has been generated. After that, the server control unit 36 ​​proceeds to step ST27.

[0062] In step ST26, the server control unit 36 ​​generates individual control information for the control vehicle 2 for which switching prohibition information has been generated. In this case, the server control unit 36 ​​generates individual control information for at least the entire section from the control vehicle 2's most recent position to the zone boundary of the first base station 4. The server control unit 36 ​​also generates information for multiple sets of locations and times that the control vehicle 2 should pass through in the said section. In Figure 10, the first waypoint WP1, the second waypoint WP2, and the third waypoint WP3 are shown on the line segment of the control vehicle 2 involved in the processing. As shown in Figure 1, the first waypoint WP1 is the point immediately before the control vehicle 2 and includes information on the time of passing through that point. The second waypoint WP2 is the point where the zone boundary of the first base station 4 and the path S of the control vehicle 2 intersect and includes information on the time of passing through that point. The third waypoint WP3 is a point on the route S of the control vehicle 2 that is outside the zone of the first base station 4 and inside the zone of the second base station 5, and includes information on the time of passage to that point. In this case, the server control unit 36 ​​generates information for at least the first waypoint WP1 and the second waypoint WP2. The server control unit 36 ​​may also generate information for the first waypoint WP1, the second waypoint WP2, and the third waypoint WP3. By specifying multiple waypoints and passage times for the route S that the control vehicle 2 will travel, even if communication with the control server device 3 is temporarily interrupted thereafter, the control vehicle 2 will be able to travel to the furthest waypoint under the assumptions of the server control unit 36. After that, the server control unit 36 ​​proceeds to step ST27.

[0063] The server control unit 36 ​​may generate the same individual control information in step ST25 as it generates in step ST26. However, if it generates information up to the third waypoint WP3 on the route S, the processing load of the server control unit 36 ​​will increase. In step ST25, the server control unit 36 ​​may generate only the information for the first waypoint WP1, for example. Alternatively, in step ST25, the server control unit 36 ​​may generate not waypoint information, but simply flag information for instructing the control vehicle 2 to accelerate, decelerate, or steer, as individual control information. For a typical control vehicle 2, the overall processing load of the server control unit 36 ​​can be reduced by generating this simplified individual control information.

[0064] In step ST27, the server control unit 36 ​​transmits the generated individual control information to the control vehicle 2 involved in the processing. If switching prohibition information has also been generated, the server control unit 36 ​​transmits the generated individual control information and the switching prohibition information to the control vehicle 2 involved in the processing. The individual control information and switching prohibition information are transmitted from the server communication device 31 through the carrier communication network 6 and the base station and received by the vehicle communication device 27 of the control vehicle 2. In the case of the control vehicle 2 in Figure 1, individual control information and switching prohibition information are generated. The individual control information and switching prohibition information are then transmitted from the server communication device 31 through the carrier communication network 6 and the first base station 4 and received by the vehicle communication device 27 of the control vehicle 2.

[0065] In step ST28, the server control unit 36 ​​determines whether it has finished generating and transmitting individual control information for all control vehicles 2 that need to be processed. If it has not finished generating and transmitting individual control information for all control vehicles 2 recorded in the vehicle position DB 43, the server control unit 36 ​​returns to step ST21. In step ST21, the server control unit 36 ​​selects a new unprocessed control vehicle 2 and repeats the processing from step ST22 to step ST28. When it has finished generating and transmitting individual control information for all control vehicles 2 recorded in the vehicle position DB 43, the server control unit 36 ​​determines that the vehicle has finished and terminates this control.

[0066] Figure 11 is a flowchart of an example of handover control by the external communication control device 16 shown in Figure 2. The external communication control device 16 of the control vehicle 2, acting as a vehicle communication control unit, repeatedly executes the handover control shown in Figure 11.

[0067] In step ST31, the external communication control device 16 determines whether the vehicle communication device 27 has received switching prohibition information from the control server device 3. If switching prohibition information has been received, the external communication control device 16 proceeds to step ST32 in order to perform immediate connection destination switching processing. If switching prohibition information has not been received, the external communication control device 16 proceeds to step ST34 in order not to perform immediate connection destination switching processing.

[0068] In step ST32, the external communication control device 16 performs connection destination switching control. The external communication control device 16 instructs the MAC circuit 66 of the vehicle communication device 27 to switch the connection destination. The MAC circuit 66 searches for a base station that can communicate at the moment and performs handover control to switch the connection destination to a base station different from the base station to which it is currently connected. As a result, for example, even if the control vehicle 2 in Figure 1 is in the zone of the first base station 4, the connection destination is immediately and forcibly switched and connected to the searchable second base station 5.

[0069] In step ST33, the external communication control device 16 sets the MAC circuit 66 of the vehicle communication device 27 to disable destination switching control. As a result, the MAC circuit 66 of the vehicle communication device 27 will not perform voluntary destination switching control based on radio wave quality after the forced destination switching control in step ST32.

[0070] In step ST34, the external communication control device 16 sets a timer (not shown) provided in the external communication control device 16. The timer measures the elapsed time since receiving the switching prohibition information, or the elapsed time since forcibly switching the connection destination.

[0071] In step ST35, the external communication control device 16 determines whether the elapsed time measured by the timer is equal to or greater than the prohibited period. Here, the prohibited period may be a fixed period, but it is preferable to set it to the period specified by the switching prohibition information. If the elapsed time is not equal to or greater than the prohibited period, the external communication control device 16 repeats this process. When the elapsed time becomes equal to or greater than the prohibited period, the external communication control device 16 proceeds to step ST36.

[0072] In step ST36, the external communication control device 16 releases the prohibition on switching control of the connection destination that was set in step ST33. As a result, the MAC circuit 66 of the vehicle communication device 27 will not perform voluntary switching control of the connection destination after performing forced switching control of the connection destination in step ST32 until the prohibition period has elapsed.

[0073] In step ST37, the external communication control device 16 clears the timer that started measuring in step ST34. After that, the external communication control device 16 terminates this control.

[0074] Figure 12 is a timing chart showing the overall flow of individual control and handover control in this embodiment. The server control for the driving control of the control vehicle 2 in Figure 12 is the same as that in Figure 4. In Figure 12, the forced handover control in Figure 11 is executed in the driving state of Figure 1.

[0075] In this case, the server control unit 36 ​​transmits individual control information for multiple waypoints up to the base station's zone boundary, along with switching prohibition information, to the control vehicle 2 connected to the first base station 4. The individual control information and switching prohibition information are transmitted to the control vehicle 2 via the first base station 4. Also, in the state shown in Figure 1, the control vehicle 2 is close to the first base station 4, so the radio quality with the first base station 4 is good. The individual control information and switching prohibition information can be reliably transmitted to the control vehicle 2.

[0076] When the vehicle communication device 27 of the control vehicle 2 receives information prohibiting switching, the external communication control device 16 instructs the vehicle communication device 27 to execute a forced connection destination switching control. As a result, the connection destination of the control vehicle 2 switches from the first base station 4 to the second base station 5. Information sent and received between the control vehicle 2 and the control server device 3 thereafter will be sent and received through the second base station 5. Immediately after the forced connection destination switching control is executed, the wireless quality between the control vehicle 2 and the second base station 5 may not be good. In addition, the control vehicle 2 has already received individual control information up to the zone boundary of the first base station 4 via the first base station 4. Furthermore, this individual control information is information from multiple waypoints. For this reason, the driving control device 12 of the control vehicle 2 can control the driving by automatic driving so that it passes through the multiple waypoints already received at a specified time, at least up to the zone boundary of the first base station 4. Even if new individual control information cannot be received immediately after the connection destination of control vehicle 2 is forcibly switched to the second base station 5, control vehicle 2 can continue automatic operation under the server control of control server device 3. Even if a temporary interruption occurs in communication between control vehicle 2 and the second base station 5 during the second or third control cycle in Figure 12, control vehicle 2 can continue automatic operation under the server control of control server device 3. Subsequently, when it becomes possible to send and receive vehicle information and individual control information through the second base station 5, control vehicle 2 can continue automatic operation under the server control of control server device 3 in accordance with the newly received individual control information from control server device 3.

[0077] As described above, in this embodiment, the server control unit 36 ​​of the control server device 3 periodically transmits individual control information as driving control information to the control vehicle 2. Furthermore, the server control unit 36 ​​generates switching prohibition information and transmits it to the control vehicle 2 along with the driving control information when the wireless quality of the first base station 4 in the control vehicle 2 satisfies switching conditions that allow switching to be determined earlier than the connection switching conditions of the vehicle communication device 27, and the control vehicle 2 is traveling toward a road or lane merging point or lane change point. When the control vehicle 2, which is traveling by automatic driving under the server control of the control server device 3, receives the switching prohibition information, the control vehicle 2 communication control device immediately and forcibly causes the vehicle communication device 27 to execute the switching control of the connection destination. Furthermore, after the forced execution, the control vehicle 2 communication control device sets the vehicle communication device 27 to prohibit the switching control of the connection destination.

[0078] As a result, the vehicle communication device 27 of the control vehicle 2 can switch the connection destination from the first base station 4 to the second base station 5 while the control vehicle 2 is moving, at the moment it receives the information prohibiting the switching of the connection destination. The vehicle communication device 27 does not perform connection destination switching control even if the control vehicle 2 moves by driving after the forced switching is performed. Moreover, the communication quality between the vehicle communication device 27 and the second base station 5 improves as the control vehicle 2 moves. Therefore, the information that the control server device 3 transmits to the control vehicle 2 is maintained in a state where it can continue to be transmitted to the control vehicle 2 through the second base station 5, and is less likely to be delayed or lost on the base station side. Furthermore, the moving control vehicle 2 receives individual control information along with the connection destination switching prohibition information described above. Therefore, even during the period when connection destination switching control is prohibited, the control vehicle 2 can be expected to continue automatic driving under the server control of the control server device 3 according to the individual control information it has already received. The control vehicle 2 can continuously perform automatic operation under the server control of the control server device 3 during the period when switching control of the connection destination is prohibited, and throughout the period before and after. In this embodiment, the automatic operation of the control vehicle 2 under the server control of the control server device 3 can be improved.

[0079] In particular, in this embodiment, the server control unit 36 ​​generates information up to the zone boundary of the first base station 4 as individual control information to be transmitted along with the switching prohibition information. The server control unit 36 ​​also generates information on multiple sets of positions and times that the control vehicle 2 will pass through in the driving section as individual control information to be transmitted along with the switching prohibition information. As a result, the control vehicle 2 continues to drive automatically according to the multiple sets of position and time information already acquired during the period when switching control of the connection destination is prohibited. The control vehicle 2 can continuously perform automatic driving under the server control of the control server device 3 during the period when switching control of the connection destination is prohibited. The control vehicle 2 can continue automatic driving under the server control of the control server device 3 during the period when switching control of the connection destination is prohibited, and throughout the period before and after.

[0080] [Second Embodiment] (Overview) In the embodiment described above, the server control unit 36 ​​generates information up to the zone boundary of the first base station 4 with which it was communicating as individual control information when switching the connection between the control vehicle 2 and the base station by control. In this embodiment, the server control unit 36 ​​generates information about the driving section during the prohibited period in which the vehicle communication device 27 itself is prohibited from performing handover control, as individual control information when switching the connection between the control vehicle 2 and the base station by control. In this embodiment, the differences from the embodiment described above will be mainly explained. Also, in this embodiment, the same reference numerals are used for components that are the same as in the embodiment described above, and their descriptions are omitted. In this case, the server control unit may transmit information about the vehicle's driving section during the prohibited period as driving control information to be transmitted along with the switching prohibition information.

[0081] (Specific Example) Figure 13 is an explanatory diagram showing the control vehicle 2 in Figure 1 traveling towards a lane change point. In Figure 13, the control server device 3 is connected to the carrier communication network 6. The control server device 3 can send and receive information with the control vehicle 2 with low latency via the carrier communication network 6 and base stations. Also in Figure 13, the control vehicle 2 is traveling in the narrowing lane 105 towards the lane change point. Another vehicle 103 is traveling in the adjacent lane 104 on the same road. In this case, the control vehicle 2 will travel along the route S shown in the figure in the lane change point in the lane 105 it is currently traveling in, and then change lanes from the lane 105 to the adjacent lane 104. The route S shown in the figure has a first waypoint WP1, a second waypoint WP2, and a third waypoint WP3.

[0082] Figure 14 is a flowchart of an example of individual control by the server control unit 36 ​​according to the first embodiment of the present invention. The server control unit 36 ​​of the control server device 3 repeatedly executes the individual control control shown in Figure 14 at each control cycle in order to transmit individual control information to the control vehicle 2. Steps ST21 to ST28 in Figure 14 are the same as in Figure 9. However, if it is determined in step ST24 that switching prohibition information has been generated, the server control unit 36 ​​proceeds to step ST29.

[0083] In step ST29, the server control unit 36 ​​generates individual control information for the control vehicle 2 for which switching prohibition information has been generated. In this case, the server control unit 36 ​​generates information on the section of the control vehicle 2 to travel during the prohibited period in which the execution of switching control of the connection destination is prohibited by the switching prohibition information. The section of the control vehicle 2 to travel during the prohibited period may be the section from the current position of the control vehicle 2 to a position within the zone of the second base station 5, beyond the zone boundary of the first base station 4, as illustrated in Figure 13. The server control unit 36 ​​also generates information on multiple sets of positions and times that the control vehicle 2 should pass through in the section of travel during the prohibited period. The server control unit 36 ​​generates information on at least the first waypoint WP1 and the second waypoint WP2 in Figure 13. The server control unit 36 ​​may also generate information on the first waypoint WP1, the second waypoint WP2, and the third waypoint WP3. Then, in step ST27, the server control unit 36 ​​transmits the switching prohibition information along with the individual control information of step ST29 to the control vehicle 2.

[0084] By specifying multiple waypoints and arrival times for the route S that the control vehicle 2 will travel, even if communication with the control server device 3 is temporarily interrupted, the control vehicle 2 will be able to travel to the furthest waypoint (for example, the second waypoint WP2) under the assumptions of the server control unit 36. Subsequently, when it becomes possible to send and receive vehicle information and individual control information through the second base station 5, the control vehicle 2 can continue automatic driving under the server control of the control server device 3 in accordance with the newly received individual control information from the control server device 3.

[0085] As described above, in this embodiment, the server control unit 36 ​​generates information on the driving section of the control vehicle 2 during the prohibited period in which the execution of switching control of the connected destination is prohibited by the switching prohibition information, as individual control information to be transmitted together with the switching prohibition information. The server control unit 36 ​​also generates information on multiple sets of positions and times that the control vehicle 2 will pass through in the driving section, as individual control information to be transmitted together with the switching prohibition information. As a result, the control vehicle 2 can continue to drive automatically according to the multiple sets of position and time information already acquired during the period in which switching control of the connected destination is prohibited. The control vehicle 2 can continuously perform automatic driving under the server control of the control server device 3 during the period in which switching control of the connected destination is prohibited. The control vehicle 2 can continue automatic driving under the server control of the control server device 3 during the period in which switching control of the connected destination is prohibited, and throughout the period before and after.

[0086] The embodiments described above are examples of preferred embodiments of the present invention, but the present invention is not limited thereto, and various modifications or changes are possible without departing from the spirit of the invention.

[0087] In the embodiment described above, the server control unit 36 ​​generates switching prohibition information and transmits it to the control vehicle 2 along with individual control information when the wireless quality of the first base station 4 in the control vehicle 2 satisfies switching conditions that allow for a switching decision to be made earlier than the connection switching conditions of the vehicle communication device 27, and the control vehicle 2 is traveling toward a road or lane merging point or lane change point. In addition, for example, the server control unit 36 ​​may also generate switching prohibition information and transmit it to the control vehicle 2 along with individual control information when the wireless quality of the first base station 4 in the control vehicle 2 satisfies switching conditions that allow for a switching decision to be made earlier than the connection switching conditions of the vehicle communication device 27.

[0088] 1...Server control system, 2...Control vehicle (vehicle), 3...Control server equipment, 4...First base station, 5...Second base station, 6...Carrier communication network, 10...Control system, 11...Sensor control device, 12...Driving control device, 13...Drive control device, 14...Steering control device, 15...Braking control device, 16...External communication control device, 19...Vehicle network, 21...GNSS receiver, 22...External camera, 23...LiDAR, 24...Laser device, 25...Accelerometer, 26...High-precision map data, 27...Vehicle communication device, 31...Server communication device, 32...Server GNSS receiver, 33...Server DB, 34...Server memory, 35...Server CPU, 36...Server control 39...Server bus, 41...Pre-processing unit, 42...Control control unit, 43...Vehicle position DB, 51...High-frequency antenna, 52...Multiplexer, 53...Radio frequency circuit, 54...High-frequency receiving amplifier, 55...Receiving mixer, 56...Receiving amplifier, 57...AD converter, 58...Received signal detector, 59...Logic circuit, 60...Oscillator, 61...VCO / PLL circuit, 62...DA converter, 63...Transmitting amplifier, 64...Transmitting mixer, 65...High-frequency power amplifier, 66...MAC circuit, 67...Host communicator, 68...Baseband circuit, 101...Main road, 102...Merging road, 103...Other vehicles, 104...Adjacent lane, 105...Narrowing lane

Claims

1. A server control system for the autonomous driving of a vehicle, wherein the server control unit of a server device periodically transmits driving control information to the vehicle via a base station that wirelessly communicates with the vehicle's vehicle communication device, the vehicle communication device performs switching control to switch the connection destination from a first base station to a second base station while the vehicle is in motion, the server control unit generates switching prohibition information to prohibit the vehicle communication device from performing the switching control of the connection destination, transmits the driving control information and the switching prohibition information to the vehicle for server control of the vehicle's autonomous driving, the vehicle has a vehicle communication control unit, and when the vehicle communication device receives the switching prohibition information, the vehicle communication control unit causes the vehicle communication device to perform the switching control of the connection destination and sets a prohibition period for the vehicle communication device from performing the switching control of the connection destination.

2. The server control unit generates the switching prohibition information and transmits it to the vehicle having the vehicle communication device when the quality of wireless communication between the vehicle communication device and the base station satisfies switching conditions that allow the vehicle communication device to make a switching decision earlier.

3. The server control unit generates the switching prohibition information when the quality of wireless communication between the vehicle communication device and the base station satisfies switching conditions that allow for a switching decision to be made earlier than the vehicle communication device, and the vehicle is traveling toward a road or lane merging point or lane change point, according to claim 2, server control system for automated driving of a vehicle.

4. The server control unit transmits, as the driving control information to be transmitted together with the switching prohibition information, information about the driving section up to the zone boundary of the first base station, or information about the driving section of the vehicle during the prohibition period, according to any one of claims 1 to 3.

5. The server control unit generates, as the driving control information transmitted together with the switching prohibition information, a plurality of sets of position and time information that the vehicle passes through in the driving section, the server control system for automatic driving of a vehicle according to claim 4.

Images