Vehicle control system and vehicle

Abstract

To make the system redundant to eliminate handover failures, and prevent the increase of communication load due to a wireless modem.SOLUTION: The vehicle control system includes: an in-vehicle terminal mounted on an unmanned dump 10 or a manned vehicle, and having a first radio modem that communicates with a base station via a first wireless line and a second radio modem that communicates with a radio base station 4 via a second wireless line; a server unit that communicates with the in-vehicle terminal via the radio base station 4; a storage unit that stores association information in which location information (LID1-LID6) of the unmanned dump 10 or the manned vehicle and permission / prohibition information to allow or prohibit the communication of the second radio modem are associated with each other; and a control unit that permits or prohibits the communication of the second radio modem depending on the position of the unmanned dump 10 or the manned vehicle based on the association information stored in the storage unit.SELECTED DRAWING: Figure 9

Description

[Technical Field]

[0001] The present invention relates to a vehicle control system and a vehicle. [Background technology]

[0002] At mining sites and other locations, there is a growing demand for autonomous driving of various vehicles from the perspective of reducing labor costs and improving safety. To meet this demand, a vehicle control system is known that enables vehicles to drive autonomously according to instructions from a control server or the like, without the need for manned operation.

[0003] For example, Patent Document 1 discloses a technology in which an emergency stop signal is sent to all vehicles traveling within a mining site when an emergency stop input device is operated. Patent Document 2 also discloses a technology in which position data is sent between vehicles to monitor the relative positions of the vehicles, and if the vehicles get too close to each other, the vehicles are slowed down or stopped to avoid interference.

[0004] Furthermore, in order to cover the entire vast area of ​​a mine site, it is necessary to configure a wireless network consisting of multiple wireless base stations at the mine site. Each of the multiple wireless base stations configures one or more wireless areas called "cells." By configuring multiple cells, a wireless network that covers the entire area of ​​a mine site can be constructed. Furthermore, when a vehicle moves between multiple cells, a process called "handover" is performed. When a vehicle moves from a first cell to a second cell, handover is a process in which the wireless base station with which it communicates is changed from the first wireless base station that configures the first cell to the second wireless base station that configures the second cell.

[0005] When a handover is performed, a large number of signals are sent and received between the vehicle-mounted terminal and the wireless base station from which the handover originates, and between the vehicle-mounted terminal and the wireless base station to which the handover is to be made. This can cause delays or packet loss in packet communication between the wireless base station and the vehicle-mounted terminal during the handover process. In the worst case scenario, the handover may fail, requiring the connection to be retried from the initial connection.

[0006] For vehicle control systems, delays and losses in packet communication during handover processing are considered "disruption time," and if the disruption time becomes too long, the vehicle must slow down or make an emergency stop to ensure safety. To improve work efficiency at mining sites, it is necessary to minimize delays due to handover processing and eliminate delays and losses in packet communication, as well as handover failures. The technologies disclosed in Patent Documents 1 and 2 do not provide a method for addressing these problems. [Prior art documents] [Patent documents]

[0007] [Patent Document 1] Japanese Patent Application Laid-Open No. 2017-72946 [Patent Document 2] Japanese Patent Application Publication No. 10-222227 Summary of the Invention [Problem to be solved by the invention]

[0008] One technology that has been considered is to provide redundancy to the system by providing multiple wireless modems so that handover will be successful for the entire system even if a handover of a wireless modem fails. However, if multiple wireless modems are required to constantly communicate with a base station to achieve system redundancy, this poses a major problem in terms of the increased communication load.

[0009] Therefore, the present invention has been made in consideration of the above problems, and provides a vehicle control system and a vehicle that achieves system redundancy to eliminate handover failures and can prevent an increase in communication load due to wireless modems. [Means for solving the problem]

[0010] The vehicle control system of the present invention comprises an in-vehicle terminal mounted on a vehicle and having a first wireless modem that communicates with a base station via a first wireless line and a second wireless modem that communicates with the base station via a second wireless line; a server device that communicates with the in-vehicle terminal via the base station; a memory unit that stores correspondence information that corresponds vehicle location information with permission / prohibition information that permits or prohibits communication by the second wireless modem; and a control unit that permits or prohibits communication by the second wireless modem depending on the vehicle location based on the correspondence information stored in the memory unit. [Effects of the Invention]

[0011] According to the vehicle control system of the present invention, it is possible to provide redundancy to the system in order to eliminate handover failures, and also to prevent an increase in the communication load caused by the wireless modem. [Brief explanation of the drawings]

[0012] [Figure 1] 1 is a schematic diagram showing an example of the overall configuration of a vehicle control system 1000 according to an embodiment. [Figure 2] 2 is a block diagram illustrating an example of the configuration of the vehicle-mounted terminal 2. FIG. [Figure 3] FIG. 2 is a block diagram illustrating an example of the configuration of the vehicle-mounted terminal 3. [Figure 4] 2 is a schematic diagram illustrating the operation of the vehicle control system 1000 according to the embodiment. FIG. [Figure 5] 1 is a schematic diagram showing how the received power of a radio signal transmitted from a radio base station 4-1 and the received power of a radio signal transmitted from a radio base station 4-2 change as an unmanned dump truck 10-1 travels on a travel road 100. FIG. [Figure 6]6 is a graph showing how delay time occurs in packet communication in first wireless modem 102-1 when the operation of FIG. 5 is performed. [Figure 7] 6 is a graph showing how delay time occurs in packet communication in second wireless modem 102-2 when the operation of FIG. 5 is performed. [Figure 8] 6 is a graph showing how delay times occur in packet communication in the vehicle-mounted terminal 3 when the operation of FIG. 5 is performed. [Figure 9] 1 is a schematic diagram showing an unmanned dump truck 10 traveling along a travel path 100 in a wireless communication area of ​​cells 7-1, 7-2, and 7-3 formed by wireless base stations 4-1, 4-2, and 4-3. [Figure 10] This is correspondence information in which permission / prohibition information for permitting or prohibiting communication by the first wireless modem 102-1 and permission / prohibition information for permitting or prohibiting communication by the second wireless modem 102-2 are stored for each section of the road 100. [Figure 11] FIG. 2 is a schematic diagram illustrating a communication protocol stack used in the vehicle control system 1000. [Figure 12] 1 is a schematic diagram showing an example of data formats of a wireless communication layer, a communication authorization layer, a secure communication layer, and an application layer. [Figure 13] 5 is a flowchart for explaining in detail the operation of a transmission system in the vehicle-mounted terminal 2 according to the embodiment. [Figure 14] 5 is a flowchart for explaining in detail the operation of a receiving system in the vehicle-mounted terminal 3 according to the embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0013] Hereinafter, the present embodiment will be described with reference to the accompanying drawings. In the accompanying drawings, functionally identical elements may be designated by the same numerals. Note that the accompanying drawings show embodiments and implementation examples according to the principles of the present disclosure, but these are for understanding the present disclosure and are not to be used to interpret the present disclosure in a limiting manner. The descriptions in this specification are merely typical examples and are not intended to limit the scope or application of the present disclosure in any way.

[0014] Although the present embodiment has been described in sufficient detail to enable those skilled in the art to implement the present disclosure, it should be understood that other implementations and forms are possible, and that changes in configuration and structure and substitutions of various elements are possible without departing from the scope and spirit of the technical ideas of the present disclosure. Therefore, the following description should not be interpreted as being limited thereto.

[0015] [Embodiment Mode] Hereinafter, a vehicle control system according to an embodiment will be described in detail with reference to the drawings. Fig. 1 is a schematic diagram showing an example of the overall configuration of a vehicle control system 1000 according to an embodiment. The vehicle control system 1000 also functions as an emergency stop system that stops an autonomous vehicle in an emergency.

[0016] 1, vehicle control system 1000 includes portable terminals 1-1 to 1-2, vehicle-mounted terminals 2-1 to 2-2, vehicle-mounted terminals 3-1 to 3-4, wireless base stations 4-1 to 4-2, a control tower 5, autonomous vehicles (hereinafter referred to as "unmanned dump trucks") 10-1 to 10-4, manned vehicles 20-1 to 20-2 operated by a driver, and a control center 30. Vehicle control system 1000 is configured to be able to perform control of the travel, emergency deceleration, emergency stop, and other operations of the unmanned dump trucks 10-1 to 10-4 and the manned vehicles 20-1 to 20-2.

[0017] The vehicle control system 1000 is installed, for example, in a mine. The unmanned dump trucks 10-1 to 10-4 are vehicles capable of autonomous travel without a driver and, in principle, are operated without a driver on board and are controlled based on the vehicle control system 1000. The unmanned dump trucks 10-1 to 10-4 are transport vehicles that load and transport cargo such as earth and sand, ore, etc. The unmanned dump trucks 10-1 to 10-4 autonomously travel unmanned along a predetermined travel path 100 within a mine site. For example, a shovel (not shown) that loads earth and sand ore into the unmanned dump truck 10-2 at a loading site 200 is arranged, and the unmanned dump truck 10-2 travels back and forth between the loading site 200 and a dumping site 300 along the travel path 100 to transport the cargo. In addition, a vehicle control supervisory device 31 and an emergency stop input device 32 are installed in the control center 30.

[0018] The number of each device is not limited to those shown in the drawings or to specific numbers. For example, there may be only one vehicle-mounted terminal and one unmanned dump truck, or there may be multiple of either or both. Also, there may be only one vehicle-mounted terminal and one manned vehicle, or there may be multiple of either or both.

[0019] Although not shown in FIG. 1, a system for supporting the autonomous traveling of the unmanned dump trucks 10-1 to 10-4 and an operation control system are provided at the work site within the mine.

[0020] The portable terminals 1-1 and 1-2 may all have the same configuration, or they may have different configurations. Hereinafter, the portable terminals 1-1 and 1-2 may be collectively referred to as the "portable terminal 1" without distinction. Similarly, the vehicle-mounted terminals 2-1 and 2-2, the vehicle-mounted terminals 3-1 to 3-4, and the wireless base stations 4-1 to 4-2 may be collectively referred to as the "vehicle-mounted terminal 2," the "vehicle-mounted terminal 3," and the "wireless base station 4," respectively without distinction. Furthermore, the unmanned dump trucks 10-1 to 10-4 may all have the same configuration, and therefore may be collectively referred to as the "unmanned dump truck 10." The manned vehicles 20-1 and 20-2 may also be collectively referred to as the "manned vehicle 20."

[0021] In this embodiment, the control object of the vehicle control system 1000 is the unmanned dump truck 10, but the autonomously moving vehicle that is the control object of the vehicle control system 1000 is not limited to the unmanned dump truck, and it is also possible to control other unmanned heavy machinery as well, and perform control similar to that of the unmanned dump truck 10.

[0022] At a mining site, in addition to the unmanned dump truck 10 that transports loads such as earth and sand, ore, and the like, manned vehicles 20 also travel. The manned vehicle 20 is configured to accommodate a driver or other passenger and is configured to be driven and operated by the driver. Examples of the manned vehicle 20 include the above-mentioned excavator, a dozer that levels the surface of the travel path 100, a water truck, a service car that patrols the mining site, and a manned dump truck.

[0023] The portable terminal 1 is a portable device that can be carried by a worker in a mining site. The portable terminal 1 has a function as an emergency stop device that sends an emergency stop command signal to instruct an emergency stop of the unmanned dump truck 10 in the event of an emergency.

[0024] The on-board terminal 2 is an on-board device mounted on the manned vehicle 20. The on-board terminal 2 also functions as an emergency stop device that sends out an emergency stop command signal, and the driver or passenger of the manned vehicle 20 can use the on-board terminal 2 to issue an emergency stop command for the unmanned dump truck 10 in the event of an emergency. This ensures safety. The emergency stop command signal can be sent, for example, from the travel path 100, the loading site 200, the dump site 300, etc. within the work site.

[0025] In this embodiment, the scope and meaning of "emergency" are not limited, and an operator or the driver of the manned vehicle 20 can determine whether an emergency has occurred and issue an emergency stop instruction at their own discretion. Generally, whether an "emergency" has occurred is determined based on whether it is necessary to stop the unmanned dump truck 10. For example, an emergency can be determined when there is a possibility of contact and interference between two unmanned dump trucks 10, or between an unmanned dump truck 10 and a manned vehicle 20. Also, an emergency can be determined when there is a possibility of contact and interference between an operator and the unmanned dump truck 10.

[0026] The vehicle-mounted terminal 3 is an on-board device mounted on the unmanned dump truck 10. The vehicle-mounted terminal 3 can receive signals transmitted from the portable terminal 1 or the vehicle-mounted terminal 2 via the wireless base station 4. This signal includes an emergency stop command signal for stopping the unmanned dump truck 10.

[0027] The vehicle-mounted terminal 3 can receive an emergency stop command signal from the portable terminal 1 or the vehicle-mounted terminal 2 via the wireless base station 4, but it may also be made possible to receive the emergency stop command signal directly from the portable terminal 1 or the vehicle-mounted terminal 2.

[0028] When the on-board terminal 3 receives the emergency stop command signal, the unmanned dump truck 10 stops traveling in response. The installation location of the antenna of the on-board terminal 3 mounted on the unmanned dump truck 10 is not limited to a specific location. As an example, the antenna can be installed in a location with good visibility of radio waves, such as on the front top surface of the unmanned dump truck 10.

[0029] Each of the multiple wireless base stations 4 forms a cell, and is capable of wireless communication with the unmanned dump trucks 10 and manned vehicles 20 located within the cell. For example, since the unmanned dump trucks 10 and manned vehicles 20 move in areas including the travel path 100, loading area 200, and dumping area 300, the multiple wireless base stations 4 are installed so that these areas are included in the cell and the unmanned dump trucks 10 and manned vehicles 20 can communicate wirelessly.

[0030] Each of the multiple wireless base stations 4 is connected to the vehicle control supervisory device 31 via the control tower 5 through wireless backhaul lines 510-1 and 510-2 and the core station 6 in the control center 30. An emergency stop command signal transmitted from the portable terminal 1 and the on-board terminal 2 passes through each wireless base station 4, the wireless backhaul line 510-1 or 510-2, the control tower 5, and reaches the vehicle control supervisory device 31 via the core station 6. The vehicle control supervisory device 31 transmits an autonomous driving control signal to the unmanned dump truck 10, thereby causing the unmanned dump truck 10 to drive autonomously. The vehicle control supervisory device 31 also has a function of distributing the emergency stop command signal transmitted from the portable terminal 1 and the on-board terminal 2 to the on-board terminals 3 mounted on all of the unmanned dump trucks 10 via the core station 6, the control tower 5, the wireless backhaul line 510-1 or 510-2, and each wireless base station 4.

[0031] The vehicle control supervisory device 31 is implemented in a general server device or computer, and does not represent a feature of the present invention, so a detailed description of the device configuration of the vehicle control supervisory device 31 will be omitted.

[0032] The system can be configured so that when an emergency stop command signal is issued from any of the portable terminals 1 or the vehicle-mounted terminals 2 to all the unmanned dump trucks 10 within a mining site, all the unmanned dump trucks 10 or only certain specific unmanned dump trucks 10 are stopped.

[0033] In addition to the core station 6 and the vehicle control supervisory device 31, the control center 30 is also equipped with an emergency stop input device 32. The vehicle control supervisory device 31 and the emergency stop input device 32 are connected to each other so that they can communicate with each other via a wired line 33. The emergency stop input device 32 is a device that issues an emergency stop command in accordance with the operation of an operator in the control center 30. Therefore, the operator in the control center 30 can issue an emergency stop command for all unmanned dump trucks 10 or only for a specific unmanned dump truck 10 by using the emergency stop input device 32 to send an emergency stop command signal directly to the vehicle control supervisory device 31. Note that although the emergency stop input device 32 has been described as being connected to the vehicle control supervisory device 31, it may also be configured to be wirelessly connected to the wireless base station 4 instead of the vehicle control supervisory device 31.

[0034] The vehicle-mounted terminal 2 and the vehicle-mounted terminal 3 are equipped with a GPS receiving function. This GPS receiving function enables the manned vehicle 20 and the unmanned dump truck 10 to acquire their own position information.

[0035] The on-board terminal 2 mounted on the manned vehicle 20 has a function of transmitting its own position information. The on-board terminal 3 mounted on the unmanned dump truck 10 can also calculate the distance between the unmanned dump truck 10 and each manned vehicle 20, using the position information of the manned vehicle 20 sent from each manned vehicle 20 and its own position information acquired from a GPS receiving function mounted on the unmanned dump truck 10. Note that the method of acquiring its own position information may of course be a method other than GPS.

[0036] Next, an example of the configuration of the vehicle-mounted terminal 2 will be described with reference to the block diagram of Fig. 2. The vehicle-mounted terminal 2 is configured to include, for example, a first transmitting / receiving antenna 101-1, a second transmitting / receiving antenna 101-2, a first wireless modem 102-1, a second wireless modem 102-2, a microcomputer device 103, an external interface (I / F) 104, a power supply device 105, a display device 106, an emergency stop button 107, a GPS receiver 108, and a GPS antenna 109.

[0037] The vehicle-mounted terminal 2 includes multiple, for example, two, wireless modems 102-1 and 102-2. The first wireless modem 102-1 and the second wireless modem 102-2 are configured with high-frequency circuits and integrated circuits, etc. The first wireless modem 102-1 and the second wireless modem 102-2 are connected to a first transmitting / receiving antenna 101-1 and a second transmitting / receiving antenna 101-2, respectively, and perform wireless communication with a wireless base station 4 according to a predetermined wireless communication method (e.g., LTE, WiFi, etc.). The first wireless modem 102-1 and the second wireless modem 102-2 are also connected to a microcomputer device 103, and transmit received signals to the microcomputer device 103. Specifically, the radio signals 110-1 and 110-2 transmitted from the radio base station 4 and received by the first transmitting / receiving antenna 101-1 and the second transmitting / receiving antenna 101-2 are input to the first radio modem 102-1 and the second radio modem 102-2, and after undergoing predetermined filtering, amplification, frequency conversion, demodulation, and error correction decoding, are output to the microcomputer device 103 as received data 112-1 and 112-2 in the secure communication layer.

[0038] In addition, the wireless modems 102-1 and 102-2 perform error correction coding, modulation, frequency conversion, amplification, and filtering on the transmission data 111-1 and 111-2 in the secure communication layer output from the microcomputer device 103 to generate wireless signals 110-1 and 110-2, and output them to the transmitting and receiving antennas 101-1 and 101-2.

[0039] The microcomputer device 103 is composed of a CPU 801 (arithmetic processing unit) and a storage device 802 (main memory, flash memory, etc.), and is connected to the first wireless modem 102-1, the second wireless modem 102-2, the external I / F 104, the power supply device 105, the display device 106, the emergency stop button 107, and the GPS receiver 108. The functions described below are realized by the CPU 801 executing programs stored in the storage device 802. The microcomputer device 103 is configured to give priority to receiving the received data 112-1 in the safety communication layer from the first wireless modem 102-1 and the received data 112-2 in the safety communication layer, whichever is received first, and to discard the data received later.

[0040] The microcomputer device 103 may be partially or entirely configured with an integrated circuit or the like. The microcomputer device 103 determines whether communication has been interrupted, which is related to functional safety, and whether the power supply device 105 is operating normally. It is desirable to use a microcomputer suitable for functional safety as the microcomputer device 103, and it is preferable that the microcomputer meets safety standards such as SIL (Safety Integrity Level). The external I / F 104 is composed of a voltage conversion unit, a protocol conversion unit, a connector, etc., and controls the interface with external devices. Specifically, it is configured to be able to convert to the voltage and protocol required for the external device. For example, the external I / F 104 can interface with a BCU (Brake Control Unit) or the like mounted on the unmanned dump truck 10.

[0041] The power supply device 105 is composed of a battery 810, a voltage converter 811, etc. The power supply device 105 has a function of converting the power supplied from the battery 810 into a required voltage using the voltage converter 811, and then supplying the voltage to each unit in the vehicle-mounted terminal 3.

[0042] The display device 106 is configured with an LED, a liquid crystal display device, or the like, and is connected to the microcomputer device 103. The display device 106 has a function of notifying an operator or a maintenance person of the normality of the power supply and the result of determining whether wireless communication has been interrupted.

[0043] The emergency stop button 107 is connected to the microcomputer device 103 and includes an operation button that allows the operator to issue an emergency stop command for the unmanned dump truck 10. Like the emergency stop input device 32 of the control center 30, the emergency stop button 107 commands an emergency stop for the unmanned dump truck 10, and this emergency stop button 107 is provided on the in-vehicle terminal 2. The emergency stop button 107 may have a push button structure that detects an instruction from the operator when pressed. The emergency stop button 107 may also have a mechanism that locks when pressed and remains pressed unless released.

[0044] The GPS receiver 108 is connected to the GPS antenna 109 and the microcomputer device 103, and acquires position information indicating the current position of the manned vehicle 20 from a GPS reception signal received via the GPS antenna 109. The GPS receiver 108 outputs the position information indicating the current position of the manned vehicle 20 to the microcomputer device 103 periodically (for example, every second).

[0045] Next, an example of the configuration of the in-vehicle terminal 3 will be described with reference to Fig. 3. The in-vehicle terminal 3 is configured to include, for example, a first transmitting / receiving antenna 101-1, a second transmitting / receiving antenna 101-2, a first wireless modem 102-1, a second wireless modem 102-2, a microcomputer device 103, an external I / F 104, a power supply device 105, a display device 106, a GPS receiver 108, and a GPS antenna 109. In other words, the in-vehicle terminal 3 may have the same configuration as the in-vehicle terminal 2, except that it does not have an emergency stop button 107.

[0046] FIG. 4 is a schematic diagram illustrating the state of wireless connections between unmanned dump trucks 10 (10-1 to 10-3), on-board terminals 3 (3-1 to 3-3), and wireless base stations 4 (4-1, 4-2) in a vehicle control system 1000 according to an embodiment. While the wireless connections of the unmanned dump truck 10 are described here, similar wireless connections can also be made for manned vehicles 20. To cover the entire area of ​​a vast mining site, the vehicle control system 1000 configures multiple wireless base stations 4 and multiple cells 7. Here, two wireless base stations 4 (4-1, 4-2) and two cells 7 (7-1, 7-2) are shown as examples.

[0047] Each of the multiple wireless base stations 4 forms one or more cells 7 as a wireless communication area. Here, two wireless base stations 4-1 and 4-2 each form one cell 7 (7-1 and 7-2), and these two cells 7-1 and 7-2 cover the entire mine. When the unmanned dump truck 10 and / or the manned vehicle 20 move across the cells 7-1 and 7-2, a procedure called handover is carried out. The following mainly describes handover for the unmanned dump truck 10, but a similar description can also be applied to the manned vehicle 20.

[0048] During the handover procedure, a large number of communication messages are sent and received via the core station 6 between the onboard terminal 3 mounted on the unmanned dump truck 10 and the wireless base station 4 at the handover source, and between the onboard terminal 3 and the wireless base station 4 at the handover destination. During the handover procedure, delays and losses may occur in packet communication between the wireless base station 4 and the onboard terminal 3. In the worst case scenario, the handover may fail, requiring a restart from the initial connection. Specifically, when the unmanned dump truck 10 moves across multiple cells 7, a handover procedure is performed, which causes delays and losses in packet communication. Because delays and losses in packet communication are considered "interruption time," if a certain interruption time is exceeded, the vehicle must slow down or make an emergency stop to ensure safety. Therefore, it is necessary to minimize the delay time due to the handover procedure and eliminate delays and losses in packet communication, and ultimately, handover failures.

[0049] The operation of the vehicle control system 1000 according to the embodiment will be described in detail with reference to Fig. 4. The vehicle-mounted terminal 3 (3-1 to 3-3) mounted on the unmanned dump truck 10 is equipped with a plurality of (for example, two) wireless modems 102-1 and 102-2 for high-speed communication and improved reliability. The two modems communicate with the wireless base station 4 using a first wireless line and a second wireless line, respectively.

[0050] For example, suppose that the unmanned dump truck 10-1 is traveling from the cell 7-1 formed by the wireless base station 4-1 toward the cell 7-2 formed by the wireless base station 4-2. Then, the received power of the radio waves transmitted from the wireless base station 4-1 and received via the first and second wireless circuits gradually decreases, and conversely, the received power of the radio waves transmitted from the wireless base station 4-2 and received via the first and second wireless circuits gradually increases.

[0051] 5 shows how the received power of the radio signal transmitted from the radio base station 4-1 and the received power of the radio signal transmitted from the radio base station 4-2 change as the unmanned dump truck 10-1 travels along the travel path 100. The vertical axis of the graph in FIG. 5 represents the received power of the radio signal transmitted from the radio base station 4-1, and the horizontal axis represents the position on the travel path (distance x from a predetermined point). In FIG. 5, the received power of the radio signal transmitted from the radio base station 4-1 and received by the first radio modem 102-1 is represented as Prx11, the received power of the radio signal transmitted from the radio base station 4-1 and received by the second radio modem 102-2 is represented as Prx12, the received power of the radio signal transmitted from the radio base station 4-2 and received by the first radio modem 102-1 is represented as Prx21, and the received power of the radio signal transmitted from the radio base station 4-2 and received by the second radio modem 102-2 is represented as Prx22.

[0052] Now, consider a case where the unmanned dump truck 10-1 travels on a travel path from the cell 7-1 formed by the wireless base station 4-1 toward the cell 7-2 formed by the wireless base station 4-2, and reaches the vicinity of the boundary between the cells 7-1 and 7-2. In this case, the received powers Prx11 and Prx12 of the wireless signals transmitted from the wireless base station 4-1 gradually decrease, while the received powers Prx21 and Prx22 of the wireless signals transmitted from the wireless base station 4-2 gradually increase. In order to maintain communication, the vehicle-mounted terminal 3-1 mounted on the unmanned dump truck 10-1 performs handover at an appropriate timing to switch from connection with the wireless base station 4-1 to connection with the wireless base station 4-2.

[0053] There are several methods for implementing handover, but here, the difference between the received power of a radio signal from the handover source radio base station 4-1 and the received power of a radio signal from the handover destination radio base station 4-2 is determined by comparing it with a threshold, and the timing of starting the handover is controlled. Here, the handover source radio base station 4-1 refers to the radio base station with which the connection was originally established and to which the connection will be terminated after the handover is completed, and the handover destination radio base station 4-2 refers to the radio base station with which a new connection will be established through the handover procedure. In the case of LTE, the threshold can also be the threshold for starting transmission of a Measurement Report message, which serves as a trigger for starting the handover procedure.

[0054] The vehicle-mounted terminal 3 of this embodiment includes a plurality of (for example, two) wireless modems 102-1 and 102-2, and the thresholds Thr1 and Thr2 for determining whether to start a handover are set to different values ​​in the plurality of wireless modems 102-1 and 102-2. For example, the threshold Thr1 for determining whether to start a handover in the first wireless modem 102-1 can be set to 3 dB, and the threshold Thr2 for determining whether to start a handover in the second wireless modem 102-2 can be set to 6 dB.

[0055] Specifically, when the difference signal D1 (=Prx21-Prx11) between the received power Prx11 of the radio signal transmitted from the radio base station 4-1 and received by the first radio modem 102-1 and the received power Prx21 of the radio signal transmitted from the radio base station 4-2 and received by the first radio modem 102-1 reaches a threshold value Thr1 (3 dB), the first radio modem 102-1 initiates a handover procedure from the radio base station 4-1 to the radio base station 4-2.

[0056] In addition, when the difference signal D2 (=Prx22-Prx12) between the received power Prx12 of the radio signal transmitted from the radio base station 4-1 and received at the second radio modem 102-2 and the received power Prx22 of the radio signal transmitted from the radio base station 4-2 and received at the second radio modem 102-2 reaches a threshold value Thr2 (6 dB), the second radio modem 102-2 initiates a handover procedure from the radio base station 4-1 to the radio base station 4-2.

[0057] The second wireless modem 102-2 uses a threshold Thr2 for initiating handover that is greater than the handover threshold Thr1 of the first wireless modem 102-1. Therefore, in the situation shown in Figure 5, the second wireless modem 102-2 will start the handover procedure later than the first wireless modem 102-1.

[0058] 6 to 8, the following describes how delay time occurs in packet communication in first wireless modem 102-1 (FIG. 6), how delay time occurs in packet communication in second wireless modem 102-2 (FIG. 7), and how delay time occurs in the entire vehicle-mounted terminal 3 (FIG. 8) when the operation of FIG. 5 is performed. In the graphs of FIGS. 6 to 8, the horizontal axis indicates the position (x) along the roadway, and the vertical axis indicates the delay time in packet communication occurring in each device.

[0059] For example, when the unmanned dump truck 10-1 reaches position x1 and the difference signal D1=Prx21-Prx11 reaches the threshold Thr1, the first wireless modem 102-1 starts the handover procedure. At this time, in addition to communication between the first wireless modem 102-1 of the vehicle-mounted terminal 3-1 and the wireless base station 4-1 or 4-2, a large number of communication messages are transmitted and received between the wireless base station 4-1, which is the handover source, and the wireless base station 4-2, which is the handover destination, via the core station 6. For example, in order to transfer the terminal information of the vehicle-mounted terminal 3-1 held in the wireless base station 4-1, which is the handover source, to the wireless base station 4-2, which is the handover destination, a large number of communication messages are transmitted and received between the wireless base stations 4-1 and 4-2. In addition, communication messages are transmitted and received to confirm whether the wireless base station 4-2, which is the handover destination, has the capacity to accept the vehicle-mounted terminal 3-1.

[0060] As shown in Fig. 6, during the execution of the handover procedure in the first wireless modem 102-1, the delay time in packet communication between the wireless base station 4-1 or 4-2 and the first wireless modem 102-1 increases at the handover position x1 of the first wireless modem 102-1. During the handover procedure, not only delays in packet communication but also packet loss may occur. In the worst case, the handover procedure may fail, requiring the user to restart the initial connection.

[0061] Furthermore, when the unmanned dump truck 10-1 reaches position x2 and the difference signal D2=Prx22-Prx12 reaches the threshold value Thr2, the second wireless modem 102-2 starts the handover procedure. At this time, similar to the first wireless modem 102-1, in addition to the communication between the second wireless modem 102-2 of the vehicle-mounted terminal 3-1 and the wireless base station 4-1 or 4-2, a large number of communication messages are transmitted and received via the core station 6 between the wireless base station 4-1, which is the handover source, and the wireless base station 4-2, which is the handover destination.

[0062] As shown in Fig. 7, during the handover procedure in the second wireless modem 102-2, the delay time in packet communication between the wireless base station 4-1 or 4-2 and the second wireless modem 102-2 increases at the handover position x2 of the second wireless modem 102-2. During the handover procedure, not only delays in packet communication but also packet loss may occur. In the worst case, the handover procedure may fail, requiring the user to restart the initial connection.

[0063] However, as described above, the microcomputer device 103 of the vehicle-mounted terminal 3-1 has a function of processing the first-arrived packet between the first wireless modem 102-1 and the second wireless modem 102-2 and discarding the later-arrived packet. Therefore, as shown in FIG. 8, at the handover point x1 of the first wireless modem 102-1 and the handover point x2 of the second wireless modem 102-2, the first-arrived packet is processed by the second wireless modem 102-2 and the first wireless modem 102-1, respectively. Therefore, even if delays occur in the first wireless modem 102-1 and the second wireless modem 102-2 at points x1 and x2, respectively, no delay occurs in packet communication processing for the vehicle-mounted terminal 3-1 as a whole. Therefore, various vehicles can operate without emergency deceleration or emergency stop processing, thereby improving mine productivity while ensuring safety. Similar effects can also be achieved even when packet loss or handover failure occurs in the wireless modem. 6 to 8 are examples for easily understanding this embodiment. In reality, variations occur, but this does not undermine the effects of this embodiment. Although not described here, the vehicle-mounted terminal 2 also includes multiple wireless modems 102-1 and 102-2, and is similarly given different handover thresholds, and can perform operations similar to those described above.

[0064] However, if the vehicle-mounted terminals 2 and 3 equipped with the first and second wireless modems 102-1 and 102-2 constantly communicate using the first and second wireless circuits, this will pose a major problem in terms of increased communication load. Furthermore, if the frequencies (channels) of the first and second wireless circuits are different, this will result in frequency (channel) exhaustion. Doubling the communication load and occupying two frequencies (channels) within the limited wireless resources is a serious problem for a single mine network, and remains a major issue.

[0065] Therefore, in a section or area having a range, it is expected that the communication load will be reduced by permitting communication of only one of the first wireless modem 102-1 and the second wireless modem 102-2 of the in-vehicle terminal 2 and the in-vehicle terminal 3 and prohibiting communication of the other. Specifically, the in-vehicle terminal 2 and the in-vehicle terminal 3, which are equipped with multiple wireless modems 102-1 and 102-2, store correspondence information in which vehicle position information, permission / prohibition information for permitting or prohibiting communication of the first wireless modem 102-1, and permission / prohibition information for permitting or prohibiting communication of the second wireless modem 102-2 are associated with each other.

[0066] For example, by allowing communication by the second wireless modem 102-2 only in the handover area (a section with a certain range) of the first wireless modem 102-1 and prohibiting communication by the second wireless modem 102-2 in other areas, a significant reduction in communication load can be expected.

[0067] 9 and 10, a specific configuration will be described in which transmission from the second wireless modem 102-2 is permitted only in the handover area of ​​the first wireless modem 102-1, and communication with the vehicle control supervisory device 31 is performed.

[0068] In FIG. 9, an unmanned dump truck 10 travels along a travel path 100 in the wireless communication area of ​​cells 7-1, 7-2, and 7-3, which are configured from wireless base stations 4-1, 4-2, and 4-3, traveling between a loading site 200 (not shown) and an earth dumping site 300 to transport cargo. The travel path 100 is divided into predetermined sections (LID1 to LID6). A first wireless modem 102-1 and a second wireless modem 102-2 control packet transmission based on permission / prohibition information set for each section. The section identifier is represented by LID. The predetermined sections (LID1 to LID6) may be sections that are permitted to travel and are determined by a control system so that the unmanned dump truck 10 can travel autonomously, or may be sections created specifically for permitting / prohibiting communication by the first wireless modem 102-1 and the second wireless modem 102-2.

[0069] 10A shows correspondence information in which permission / prohibition information for permitting or prohibiting communication by the first wireless modem 102-1 and permission / prohibition information for permitting or prohibiting communication by the second wireless modem 102-2 are stored for each section of the travel road 100. This correspondence information is used by the microcomputer device 103 to determine whether to permit or prohibit communication by the first wireless modem 102-1 and communication by the second wireless modem 102-2. Note that the identifiers of the permission / prohibition information for permitting or prohibiting communication by the first wireless modem 102-1 and the permission / prohibition information for permitting or prohibiting communication by the second wireless modem 102-2 are referred to as RIDs. Furthermore, the areas of the loading site 200 and the dumping site 300 are defined as sections (LIDs). Of course, the loading site 200 and the dumping site 300 may be divided and defined as multiple sections (LIDs) rather than as a single section. The correspondence information may be stored in the vehicle-mounted terminals 2 and 3, or may be stored in a server device (control center 30). When the correspondence information is stored in the server device (control center 30), the unmanned dump truck 10 or the manned vehicle 20 acquires the correspondence information from the server device (control center 30).

[0070] For example, since section LID4 is the boundary between cells 7-1 and 7-2 formed by wireless base stations 4-1 and 4-2 and a handover occurs, the first wireless modem 102-1 and the second wireless modem 102-2 mounted on the unmanned dump truck 10-4 traveling on section LID4 have RID1 and RID2 set to "permitted" in section LID4 according to the correspondence information in (a) of Figure 10. Therefore, in section LID4, the microcomputer device 103 is controlled so that packets are transmitted from both the first wireless modem 102-1 and the second wireless modem 102-2 mounted on the unmanned dump truck 10-4.

[0071] On the other hand, in section LID2, the vehicle travels within cell 7-2 formed by wireless base station 4-2, and therefore no handover occurs, and therefore the first wireless modem 102-1 and second wireless modem 102-2 mounted on the unmanned dump truck 10-1 traveling in section LID2 have RID1 set to "permitted" and RID2 set to "prohibited" in section LID4 according to the correspondence information in (a) of Figure 10. Therefore, the microcomputer device 103 is controlled so that packets are transmitted only from the first wireless modem 102-1 mounted on the unmanned dump truck 10-1 in section LID2.

[0072] Furthermore, since section LID1, which is an excavation site, includes the boundary between cells 7-2 and 7-3 formed by wireless base stations 4-2 and 4-3 and handovers will occur, the first wireless modem 102-1 and the second wireless modem 102-2 mounted on the unmanned dump truck 10-3 traveling in section LID1 have RID1 and RID2 in section LID1 set to "permitted" in accordance with the correspondence information in FIG. 10(a). Therefore, the microcomputer device 103 is controlled to transmit packets from both the first wireless modem 102-1 and the second wireless modem 102-2 mounted on the unmanned dump truck 10-3. In practice, since handovers may occur at the excavation site when the loading platform of the unmanned dump truck 10 is raised or lowered, it is desirable to set multiple RIDs to "permitted," not just at cell boundaries.

[0073] 10, the correspondence information in which the vehicle position information, the permission / prohibition of communication by the first wireless modem 102-1, and the permission / prohibition of communication by the second wireless modem 102-2 are associated with each other has been described as being stored in advance in the microcomputer device 103, but it may also be updated as appropriate over a wireless line from the vehicle control supervisory device 31 via the wireless base station 4. Furthermore, since the vehicle control supervisory device 31 manages the position information of the unmanned dump truck 10, a transmission permission instruction may also be given directly from the vehicle control supervisory device 31 over a wireless line via the wireless base station 4.

[0074] 10(a) associates vehicle location information with permission / prohibition of communication by the first wireless modem 102-1 and permission / prohibition of communication by the second wireless modem 102-2, but if communication by the first wireless modem 102-1 is always permitted, for example, permission / prohibition of communication by the first wireless modem 102-1 may not be required, as shown in FIG. 10(b). In other words, the correspondence information may associate vehicle location information with permission / prohibition of communication by the second wireless modem 102-2.

[0075] A communication protocol stack used in the vehicle control system 1000 will be described with reference to Fig. 11. Fig. 11 is a diagram showing an example of communication protocol stacks of the portable terminal 1, the vehicle-mounted terminal 2, the vehicle-mounted terminal 3, and the wireless base station 4.

[0076] The communication line in the vehicle control system 1000 according to the embodiment uses a protocol stack including four communication layers. For example, the portable terminal 1, the in-vehicle terminal 2, the in-vehicle terminal 3, and the wireless base station 4 mutually transmit and receive data configured from a protocol stack including a wireless communication layer (first communication layer), a communication permission layer (second communication layer), a safety communication layer (third communication layer), and an application layer (fourth communication layer).

[0077] The wireless communication layers 121, 321, and 421 are layers defined by a communication profile aimed at establishing and maintaining communication as wireless communication, and are responsible for communication functions based on this. The communication permission layers 122, 322, and 422 are layers defined by a communication profile aimed at permitting transmission of transmission data and selecting reception of reception data, and are responsible for communication functions based on this. The safety communication layers 123, 323, and 423 are layers defined by a communication profile aimed at functional safety as safety communication, and are responsible for communication functions based on this. The application layers 124, 324, and 424 are layers responsible for the user interface with operators and maintenance personnel.

[0078] When the mobile terminal 1, the in-vehicle terminal 2, the in-vehicle terminal 3, and the wireless base station 4 communicate with each other, the communication connection and maintenance of the communication are performed based on the communication profile for each layer. For example, when the mobile terminal 1, the in-vehicle terminal 2, and the wireless base station 4 communicate with each other, the wireless communication layer 121 of the mobile terminal 1 and the in-vehicle terminal 2 and the wireless communication layer 421 of the wireless base station 4 establish a communication connection using a mutually recognizable format. The communication authorization layer 122 of the mobile terminal 1 and the in-vehicle terminal 2 and the communication authorization layer 422 of the wireless base station 4 similarly establish a communication connection using a mutually recognizable format. The safety communication layer 123 of the mobile terminal 1 and the in-vehicle terminal 2 and the safety communication layer 423 of the wireless base station 4 similarly establish a communication connection using a mutually recognizable format. The application layer 124 of the mobile terminal 1 and the in-vehicle terminal 2 and the application layer 424 of the wireless base station 4 similarly establish a communication connection using a mutually recognizable format.

[0079] Similarly, when the vehicle-mounted terminal 3 and the wireless base station 4 communicate, the wireless communication layer 321 of the vehicle-mounted terminal 3 and the wireless communication layer 421 of the wireless base station 4 establish a communication connection using a mutually recognizable format. The communication permission layer 322 of the vehicle-mounted terminal 3 and the communication permission layer 422 of the wireless base station 4 also establish a communication connection using a mutually recognizable format. The safety communication layer 323 of the vehicle-mounted terminal 3 and the safety communication layer 423 of the wireless base station 4 also establish a communication connection using a mutually recognizable format. The application layer 324 of the vehicle-mounted terminal 3 and the application layer 424 of the wireless base station 4 also establish a communication connection using a mutually recognizable format. Note that the data to be transmitted and received is encapsulated and de-encapsulated each time it crosses each layer.

[0080] The microcomputer device 103 performs functions provided by the application layer 124, safety communication layer 123, and communication permission layer 122 in the portable terminal 1 and the in-vehicle terminal 2 in Fig. 11. As a function of the application layer 124, the microcomputer device 103 generates transmission data including an emergency stop signal indicating whether the emergency stop button 107 has been pressed or not, and location information indicating its own current location sent from the GPS receiver. The microcomputer device 103 transfers the generated transmission data to the safety communication layer 123, which is a lower layer.

[0081] Among the emergency stop signals, a signal indicating that the emergency stop button 107 has been pressed is an emergency stop command signal, which commands the stop of each unmanned dump truck 10. Among the emergency stop signals, a signal indicating that the emergency stop button 107 has not been pressed is not an emergency stop command signal. Note that the emergency stop signal (emergency stop command signal) may be transmitted when the emergency stop button 107 has been pressed, and may not be transmitted when the emergency stop button 107 has not been pressed. Additionally, as a function of the safety communication layer 123, the microcomputer device 103 adds control information (described below) to transmission data transferred from the application layer 124. This control information performs transmission processing based on a communication profile intended for functional safety. This transmission processing is processing for implementing safety measures against any or all of the threats of data corruption, repetition, incorrect order, omission, delay, insertion, spoofing, and wrong destination.

[0082] 12 is a schematic diagram showing an example of data formats of the wireless communication layer, the safety communication layer (communication permission layer), and the application layer. The transmission data in the application layer, which is generated in the application layer 124 (FIG. 11) and includes the emergency stop signal and position information, becomes DATA 1233 in the safety communication layer 123 (communication permission layer 122). In this way, the transmission data in the application layer 124 includes the emergency stop signal and position information of the portable terminal 1 or the in-vehicle terminal 2 (manned vehicle 20).

[0083] The transmission data in the application layer 124 sent as DATA 1233 is assigned a serial number 1231, an ID 1232, and a safety code 1234 as safety measures for functional safety. The serial number 1231 is a serial number (sequence number) managed within the transmitting portable terminal 1 or in-vehicle terminal 2. The ID 1232 is identification information for uniquely identifying the transmitting portable terminal 1 or in-vehicle terminal 2. The safety code 1234 is a code for implementing safety measures against threats such as the above-mentioned data corruption, repetition, incorrect order, deletion, delay, insertion, spoofing, and wrong destination.

[0084] In this way, the transmission data in the safety communication layer 123 includes an emergency stop signal, the position information of the portable terminal 1 or the vehicle-mounted terminal 2, that is, the manned vehicle 20, and the safety code 1234.

[0085] The microcomputer device 103 adds this control information to DATA 1233 to generate transmission data 111-1 and 111-2 in the safety communication layer 123. Before the transmission data 111-1 and 111-2 are output to the first wireless modem 102-1 and the second wireless modem 102-2, the communication permission layer 122 determines whether to permit transmission of the transmission data 111-1 and 111-2 as described in Figures 9 and 10. Note that the transmission data 111-1 in the safety communication layer 123 to the first wireless modem 102-1 and the transmission data 111-2 in the safety communication layer 123 to the second wireless modem 102-2 have the same data format, and the transmission data 111-1 and 111-2 in the safety communication layer 123 and the transmission data 111-1 and 111-2 in the communication permission layer 122 also have the same data format. Note that the data format in Figure 12 is merely an example and is not limited to this.

[0086] The first wireless modem 102-1 and the second wireless modem 102-2 have the function of the wireless communication layer 121 shown in Fig. 11. In the wireless communication layer 121, the first wireless modem 102-1 and the second wireless modem 102-2 process the transmission data 111-1 and 111-2 in the secure communication layer 123 (communication permission layer 122) that are generated in the secure communication layer 123 and whose transmission is permitted by the communication permission layer 122, based on a communication profile intended to establish a wireless communication connection and maintain communication.

[0087] 12, in the wireless communication layer 121, transmission data 111-1 and 111-2 in the secure communication layer 123 (communication permission layer 122) permitted for transmission by the communication permission layer 122 becomes a payload 1212, and a header 1211 for the purpose of connecting and maintaining communication and a cyclic redundancy code (CRC) 1213 for detecting data errors are added to generate transmission data in the wireless communication layer 121. The transmission data in the wireless communication layer 121 is divided into a plurality of subframes S (S1 to Sn) and transmitted. Note that the data format of the transmission data in the wireless communication layer in FIG. 12 is merely an example and is not limited to this.

[0088] The transmission data in the wireless communication layer 121 includes an emergency stop signal and location information of the portable terminal 1 or the vehicle-mounted terminal 2, i.e., the manned vehicle 20, with data added based on a communication profile for the purpose of establishing a wireless communication connection and maintaining communication.

[0089] In this way, by adding data with different functions to each communication layer, it is possible to design each function independently for each communication layer.

[0090] The transmission data in the wireless communication layer 121 generated by the wireless communication layer 121 is timing-adjusted so that it is transmitted in a predetermined subframe, and then subjected to processes such as error correction coding, modulation, frequency conversion, amplification, and filtering to generate wireless signals 110-1 and 110-2, which are then sent to the transmitting / receiving antenna 101. The transmitting / receiving antennas 101-1 and 101-2 radiate the wireless signals 110-1 and 110-2 generated by the first wireless modem 102-1 and the second wireless modem 102-2 toward the wireless base station 4.

[0091] On the other hand, the transmitting and receiving antennas 101-1 and 101-2 receive radio signals 110-1 and 110-2 on the downlink radio line transmitted from the radio base station 4, and send these radio signals to the first radio modem 102-1 and the second radio modem 102-2. The first radio modem 102-1 and the second radio modem 102-2 perform processing such as filtering, amplification, frequency conversion, demodulation, and error correction decoding on the radio signals 110-1 and 110-2 transmitted from the transmitting and receiving antennas 101-1 and 101-2 to generate received data in the radio communication layer 121. The data format of the received data in the radio communication layer 121 is the same as the transmitted data in the radio communication layer 121 in FIG. 12.

[0092] As a function of the wireless communication layer 121, the first wireless modem 102-1 and the second wireless modem 102-2 perform reception processing based on a communication profile intended for establishing a wireless communication connection and maintaining communication on reception data in the wireless communication layer 121 generated by the first wireless modem 102-1 and the second wireless modem 102-2, and generate reception data 112-1 and 112-2 in the secure communication layer 123 (communication permission layer 122). Note that the data format of the reception data 112 in the secure communication layer 123 (communication permission layer 122) is the same as the transmission data 111 in the secure communication layer 123 (communication permission layer 122) in Fig. 12. Furthermore, the reception processing based on the communication profile intended for establishing a wireless communication connection and maintaining communication includes, for example, synchronization detection, synchronization maintenance, error detection, etc.

[0093] After performing these processes, the first wireless modem 102-1 and the second wireless modem 102-2 extract the PAYLOAD 1212 from the received data in the wireless communication layer 121, i.e., the received data 112-1 and 112-2 in the secure communication layer 123 (communication permission layer 122). The first wireless modem 102-1 and the second wireless modem 102-2 output the generated received data 112-1 and 112-2 in the secure communication layer 123 (communication permission layer 122) to the microcomputer device 103.

[0094] 2 performs a process for receiving data 112-1 and 112-2 in the safety communication layer 123 (communication permission layer 122) generated by the first wireless modem 102-1 and the second wireless modem 102-2, in which the received data in the safety communication layer 123 (communication permission layer 122) that arrives first in the communication permission layer 122 is validated and the received data in the safety communication layer 123 (communication permission layer 122) that arrives later is discarded. Next, the microcomputer device 103 performs a receiving process for the received data 112 in the safety communication layer 123 (communication permission layer 122) that arrives first in the safety communication layer 123 (communication permission layer 122) based on a communication profile aimed at functional safety as safety communication in the safety communication layer 123. The microcomputer device 103 then generates DATA 1233 from the received data 112 in the safety communication layer 123. The DATA 1233 generated here is received data in the application layer 124, and is response data and control data in response to the emergency stop signal and position information data transmitted by the microcomputer device 103 itself. The configuration and operation of the vehicle-mounted terminal 2 have been described above, but the configuration and operation of the portable terminal 1 are also similar.

[0095] The microcomputer device 103 of the in-vehicle terminal 3 implements functions provided by the application layer 324, safety communication layer 323, and communication permission layer 322 in the in-vehicle terminal 3 of Fig. 11. As a function of the application layer 324, the microcomputer device 103 generates transmission data including a response signal to an emergency stop signal indicating whether or not the emergency stop button 107 of the portable terminal 1 or the in-vehicle terminal 2 has been pressed, and location information indicating its own current location sent from the GPS receiver 108. The microcomputer device 103 transfers the generated transmission data to the lower layer, the safety communication layer 323. The response signal to the emergency stop signal is a signal indicating whether or not the emergency stop signal indicating whether or not the emergency stop button 107 of the portable terminal 1 or the in-vehicle terminal 2 has been pressed has been correctly received.

[0096] Additionally, as a function of the safety communication layer 323, the microcomputer device 103 adds control information (described later) to transmission data in the application layer 324 transferred from the application layer 324. This control information performs transmission processing based on a communication profile aimed at functional safety. This transmission processing is processing for implementing safety measures against any or all of the threats of data corruption, repetition, incorrect order, loss, delay, insertion, spoofing, and wrong destination.

[0097] 12 is a diagram showing an example of data formats of the wireless communication layer, the safety communication layer (communication permission layer), and the application layer. The application layer 324 transmission data, which is generated in the application layer 324 (FIG. 11) and includes a response signal to the emergency stop signal and location information, becomes DATA1233 in the safety communication layer 323 (communication permission layer 322). In this way, the transmission data in the application layer 324 includes location information of the vehicle-mounted terminal 3.

[0098] The transmission data in the application layer 324 sent as DATA 1233 is assigned a serial number 1231, an ID 1232, and a safety code 1234 as safety measures for functional safety. The serial number 1231 is a serial number (sequence number) managed internally by the sending vehicle-mounted terminal 3. The ID 1232 is identification information for uniquely identifying the sending vehicle-mounted terminal 3. The safety code 1234 is a code for implementing safety measures against threats such as the above-mentioned data corruption, repetition, incorrect order, deletion, delay, insertion, spoofing, and wrong destination.

[0099] In this way, the communication data in the safety communication layer 323 includes a response signal to the emergency stop signal, the position information of the vehicle-mounted terminal 3, and the safety code 1234.

[0100] The microcomputer device 103 adds this control information to DATA 1233 to generate transmission data 111-1 and 111-2 in the safety communication layer 323. Before the transmission data 111-1 and 111-2 are output to the first wireless modem 102-1 and the second wireless modem 102-2, the communication permission layer 322 determines whether to permit transmission of the transmission data 111-1 and 111-2 as described in Figures 9 and 10. The transmission data 111-1 and 111-2 in the safety communication layer may be the same data. The transmission data 111-1 in the safety communication layer 323 to the first wireless modem 102-1 and the transmission data 111-2 in the safety communication layer 323 to the second wireless modem 102-2 have the same data format, and the transmission data 111-1 and 111-2 in the safety communication layer 323 and the transmission data 111-1 and 111-2 in the communication permission layer 322 also have the same data format. The data format in FIG. 12 is merely an example and is not limited to this.

[0101] The first wireless modem 102-1 and the second wireless modem 102-2 have the function of the wireless communication layer 321 shown in Fig. 11. In the wireless communication layer 321, the first wireless modem 102-1 and the second wireless modem 102-2 perform processing based on a communication profile for the purpose of establishing a wireless communication connection and maintaining communication on the transmission data 111-1 and 111-2 in the safety communication layer 323 (communication permission layer 322) that is generated in the safety communication layer 323 and permitted for communication by the communication permission layer 322.

[0102] 12, in the wireless communication layer 321, the transmission data 111-1 and 111-2 in the secure communication layer 323 (communication permission layer 322) permitted for transmission by the communication permission layer 322 becomes a PAYLOAD 1212, and a HEADER 1211 for the purpose of connecting and maintaining communication and a CRC (Cyclic Redundancy Code) 1213 for detecting data errors are added to generate the transmission data in the wireless communication layer 321. The transmission data in the wireless communication layer 321 is divided into a plurality of subframes S (S1 to Sn) and transmitted. Note that the data format of the transmission data in the wireless communication layer in FIG. 12 is merely an example and is not limited to this.

[0103] The transmission data in the wireless communication layer 321 includes a response signal to the emergency stop signal and the location information of the vehicle-mounted terminal 3, i.e., the unmanned dump truck 10, with data added based on a communication profile for the purpose of establishing a wireless communication connection and maintaining communication.

[0104] In this way, by adding data with different functions to each communication layer, it is possible to design each function independently for each communication layer.

[0105] The transmission data in the wireless communication layer generated by the wireless communication layer 321 is timing-adjusted so that it is transmitted in a predetermined subframe, and then subjected to processes such as error correction coding, modulation, frequency conversion, amplification, and filtering to generate wireless signals 110-1 and 110-2, which are then sent to the transmitting / receiving antenna 101. The transmitting / receiving antennas 101-1 and 101-2 radiate the wireless signals 110-1 and 110-2 generated by the first wireless modem 102-1 and the second wireless modem 102-2 toward the wireless base station 4.

[0106] On the other hand, the transmitting and receiving antennas 101-1 and 101-2 receive radio signals 110-1 and 110-2 on the downlink radio line transmitted from the radio base station 4, and send these radio signals to the first radio modem 102-1 and the second radio modem 102-2. The first radio modem 102-1 and the second radio modem 102-2 perform processing such as filtering, amplification, frequency conversion, demodulation, and error correction decoding on the radio signals 110-1 and 110-2 transmitted from the transmitting and receiving antennas 101-1 and 101-2 to generate radio communication received data. The data format of the received data in the radio communication layer 321 is the same as the transmitted data in the radio communication layer 321 in FIG. 12.

[0107] As a function of the wireless communication layer 321, the first wireless modem 102-1 and the second wireless modem 102-2 perform reception processing based on a communication profile intended for establishing a wireless communication connection and maintaining communication on reception data in the wireless communication layer 321 generated by the first wireless modem 102-1 and the second wireless modem 102-2, and generate reception data 112-1 and 112-2 in the safety communication layer 323 (communication permission layer 322). Note that the data format of the reception data 112 in the safety communication layer 323 (communication permission layer 322) is the same as the transmission data 111 in the safety communication layer 323 (communication permission layer 322) in Fig. 12. Furthermore, the reception processing based on the communication profile intended for establishing a wireless communication connection and maintaining communication includes, for example, synchronization detection, synchronization maintenance, error detection, etc.

[0108] After performing these processes, the first wireless modem 102-1 and the second wireless modem 102-2 extract the PAYLOAD 1212 from the received data in the wireless communication layer, i.e., the received data 112-1 and 112-2 in the secure communication layer 323 (communication permission layer 322). The first wireless modem 102-1 and the second wireless modem 102-2 output the generated received data 112-1 and 112-2 in the secure communication layer 323 (communication permission layer 322) to the microcomputer device 103.

[0109] The microcomputer device 103 performs a process for the received data 112-1, 112-2 in the safety communication layer 323 (communication permission layer 322) generated by the first wireless modem 102-1 and the second wireless modem 102-2, in which the received data in the safety communication layer 323 (communication permission layer 322) that arrives earlier in the communication permission layer 322 is valid and the received data in the safety communication layer 323 (communication permission layer 322) that arrives later is discarded. Next, the microcomputer device 103 performs a reception process for the received data 112 in the safety communication layer 323 (communication permission layer 322) that arrives earlier in the safety communication layer 323 (communication permission layer 322) based on a communication profile aimed at functional safety as safety communication in the safety communication layer 323. The microcomputer device 103 then generates DATA 1233 from the received data 112 in the safety communication layer 323. The DATA 1233 generated here is the received data in the application layer 324, and is response data and control data in response to the position information data transmitted by the microcomputer device 103.

[0110] Next, the operation of the transmission system in the vehicle-mounted terminal 2 of the embodiment will be described in detail with reference to the flowchart of Fig. 13. The flowchart of Fig. 13 is assumed to be executed at a certain predetermined time (for example, 1 second) interval (step S001).

[0111] The in-vehicle terminal 2 sets the handover threshold Thr1 of the wireless modem 102-1 stored in the storage device 802 of the microcomputer device (controller) 103 to the wireless modem 102-1 (step S002). For example, the handover threshold Thr1 of the first wireless modem 102-1 is set to 3 dB. Note that the handover threshold Thr1 of the wireless modem 102-1 stored in the storage device 802 of the microcomputer device 103 may be updated as needed over a wireless line from the vehicle control supervisory device 31 via the wireless base station 4.

[0112] Furthermore, the in-vehicle terminal 2 sets the handover threshold Thr2 of the second wireless modem 102-2, which is stored in the storage device 802 of the microcomputer device 103, to the second wireless modem 102-2 (step S006). For example, the handover threshold Thr2 of the second wireless modem 102-2 is set to 6 dB. Note that the handover threshold Thr2 of the wireless modem 102-2, which is stored in the storage device 802 of the microcomputer device 103, may be updated as needed over a wireless line from the vehicle control supervisory device 31 via the wireless base station 4.

[0113] Furthermore, the thresholds Thr1 and Thr2 may be static values ​​determined in advance from the model, maximum traveling speed, and maximum load capacity of the manned vehicle 20, or may be dynamic values ​​determined from the model, current traveling speed, and current load capacity of the manned vehicle 20. The vehicle-mounted terminal 2 may receive detection signals from a speed sensor of the manned vehicle 20 and a weight sensor that measures the weight of the load from the external I / F 104, and may determine the thresholds Thr1 and Thr2 according to these detection signals.

[0114] After the handover threshold Thr1 of the first wireless modem 102-1 is set, the GPS antenna 109 of the vehicle-mounted terminal 2 receives a GPS signal (step S003), and based on this GPS signal, the GPS receiver 108 acquires location information indicating the current location of the manned vehicle 20 (step S004). Then, the microcomputer device 103 generates its own location information data for the first wireless modem 102-1 (step S005).

[0115] After the handover threshold Thr2 of the second wireless modem 102-2 is set, the GPS antenna 109 of the vehicle-mounted terminal 2 receives a GPS signal (step S007), and based on the GPS signal, the GPS receiver 108 acquires location information indicating the current location of the manned vehicle 20 (step S008). Then, the microcomputer device 103 generates its own location information data for the second wireless modem 102-2 (step S009).

[0116] Next, the process proceeds to step S010, where it is determined whether or not the emergency stop button 107 is pressed on the vehicle-mounted terminal 2. If it is determined that the emergency stop button 107 is not pressed (No in step S010), the microcomputer device 103 generates an emergency stop signal "0" in the application layer 124 (step S011). On the other hand, if it is determined that the emergency stop button 107 is pressed (Yes in step S010), the microcomputer device 103 generates an emergency stop signal "1" in the application layer 124 (step S012). The emergency stop signal "1" is a signal indicating that the emergency stop button 107 has been pressed. The emergency stop signal "0" is a signal indicating that the emergency stop button 107 has not been pressed.

[0117] Then, the microcomputer device 103 generates transmission data in the application layer 124 including the obtained position information and an emergency stop signal ("0" or "1") (step S013). The generated transmission data in the application layer 124 undergoes transmission processing required for functional safety in the safety communication layer 123, and then the communication permission layer 122 determines whether to permit transmission (steps S015 and S018), and the data is transmitted to the first wireless modem 102-1 and the second wireless modem 102-2 (steps S016 and S019). Based on the correspondence information shown in Fig. 10, the microcomputer device 103 determines whether to permit transmission for the first wireless modem 102-1 in the communication permission layer 122 (step S015), and determines whether to permit transmission for the second wireless modem 102-2 in the communication permission layer 122 (step S018).

[0118] In Fig. 13, the on-board terminal 2 of the manned vehicle 20 determines whether to permit transmission from the first wireless modem 102-1 and the second wireless modem 102-2 based on the correspondence information shown in Fig. 10. Note that the on-board terminal 3 of the unmanned dump truck 10 may also determine whether to permit transmission from the first wireless modem 102-1 and the second wireless modem 102-2 based on the correspondence information shown in Fig. 10.

[0119] The first wireless modem 102-1 performs processing such as error correction coding, modulation, frequency conversion, amplification, and filtering, which are transmission processing required for wireless communication in the wireless communication layer 121, on the received data (step S016), and transmits a wireless signal from the transmitting / receiving antenna 101-1 (step S017). After completion of step S017, the process returns to START (S001) every second, and the same operations are repeated.

[0120] Similarly, the second wireless modem 102-2 performs processing such as error correction coding, modulation, frequency conversion, amplification, and filtering, which are transmission processing required for wireless communication in the wireless communication layer 121, on the received data (step S019), and transmits a wireless signal from the transmitting / receiving antenna 101-2 (step S020). After the end of step S020, the process returns to START (S001) every second, and the same operations are repeated.

[0121] 13, the vehicle-mounted terminal 2 periodically transmits its own location information, and while the emergency stop button 107 is pressed (step S010: Yes), the emergency stop signal is continuously transmitted as "1" (i.e., the emergency stop command signal is transmitted). Also, if the emergency stop button 107 is released (step S010: No), the microcomputer device 103 transmits the emergency stop signal as "0." Note that although the transmission operation of the vehicle-mounted terminal 2 has been described with reference to the flowchart of FIG. 13, the transmission operation of the portable terminal 1 is similar.

[0122] Next, the operation of the reception system in the vehicle-mounted terminal 3 will be described in detail with reference to the flowchart in Fig. 14. The flowchart in Fig. 14 is assumed to be executed at a certain predetermined time interval (for example, 1 second) (step S101).

[0123] The in-vehicle terminal 3 sets the handover threshold Thr1 of the first wireless modem 102-1 stored in the storage device 802 of the microcomputer device 103 to the wireless modem 102-1 (step S102). For example, the handover threshold Thr1 of the first wireless modem 102-1 is set to 3 dB. Note that the handover threshold Thr1 of the wireless modem 102-1 stored in the storage device 802 of the microcomputer device 103 may be updated as needed from the vehicle control supervisory device 31 over a wireless line via the wireless base station 4.

[0124] Furthermore, the in-vehicle terminal 3 sets the handover threshold Thr2 of the second wireless modem 102-2, which is stored in the storage device 802 of the microcomputer device 103, to the second wireless modem 102-2 (step S105). For example, the handover threshold Thr2 of the second wireless modem 102-2 is set to 6 dB. Note that the handover threshold Thr2 of the second wireless modem 102-2, which is stored in the storage device 802 of the microcomputer device 103, may be updated as appropriate over a wireless line from the vehicle control supervisory device 31 via the wireless base station 4.

[0125] Furthermore, the threshold values ​​Thr1 and Thr2 may be static values ​​determined in advance from the model, maximum traveling speed, and maximum load capacity of the unmanned dump truck 10, or may be dynamic values ​​determined from the model, current traveling speed, and current load capacity of the unmanned dump truck 10. The vehicle-mounted terminal 3 may receive detection signals from a speed sensor of the unmanned dump truck 10 and a weight sensor that measures the weight of the load from the external I / F 104, and may determine the threshold values ​​Thr1 and Thr2 in accordance with these detection signals.

[0126] When a wireless signal is received from the first transmitting / receiving antenna 101-1 (step S003), the wireless communication layer 321 of the first wireless modem 102-1 performs the necessary reception processing for wireless communication, such as filtering, amplification, frequency conversion, demodulation, and error correction decoding (step S104).

[0127] Similarly, when a radio signal is received from the second transmitting / receiving antenna 101-2 (step S106), the received radio signal is subjected to the necessary receiving processes for wireless communication, such as filtering, amplification, frequency conversion, demodulation, and error correction decoding, in the wireless communication layer 321 of the second wireless modem 102-2 (step S107).

[0128] The microcomputer device 103 performs processing for the received data 112-1, 112-2 in the safety communication layer 323 (communication permission layer 322) generated by the first wireless modem 102-1 and the second wireless modem 102-2, by first validating the received data 112 in the safety communication layer 323 (communication permission layer 322) that arrived earlier in the communication permission layer 322, and discarding the received data in the safety communication layer 323 (communication permission layer 322) that arrived later (step S108).

[0129] The microcomputer device 103 then generates DATA 1233 from the received data 112 in the safety communication layer 323 (communication permission layer 322), for whichever of the received data 112-1 and 112-2 arrives first. The DATA 1233 generated here is the received data in the application layer 324, and includes response data and control data in response to the emergency stop signal and the position information data transmitted by the microcomputer device 103 itself.

[0130] Next, the process proceeds to step S110, where the communication interval is measured from the difference between the time of the previously received data and the time of the currently received data, and it is determined whether this measured communication interval exceeds a predetermined interruption time.

[0131] If it is determined that the measured communication interval does not exceed the predetermined disruption time (No in step S110), the microcomputer device 103 generates a disruption determination signal "0" in the application layer 324 (step S111). On the other hand, if it is determined that the communication interval exceeds the predetermined disruption time (Yes in step S110), the microcomputer device 103 generates a disruption determination signal "1" in the application layer 324 (step S112). The disruption determination signal "1" means that communication has been disrupted for more than the predetermined time.

[0132] Then, the microcomputer device 103 generates control data including the obtained disruption determination signal ("0" or "1") and an emergency stop signal (step S113). The generated control data is converted by the external I / F 104 into a voltage and protocol required for the external device and output to the external device (step S114). The external device is connected to, for example, a BCU (Brake Control Unit) mounted on the unmanned dump truck 10. After step S114 ends, the process loops back to START (S101) every second. Note that the disruption determination signal and emergency stop signal output from the external I / F 104 to the external device cause the unmanned dump truck 10 to perform processes such as emergency deceleration or emergency stop, but the details of this determination can be selected appropriately in the unmanned dump truck 10, etc.

[0133] As described above, according to the system of the embodiment, it is possible to provide a vehicle control system that minimizes an increase in communication load, eliminates delays and losses in packet communication, and even handover failures, and enables improved productivity while ensuring the safety of various vehicles.

[0134] The first wireless link and the second wireless link may be different wireless systems. For example, the first wireless link may be LTE and the second wireless link may be WiFi. Although the handover threshold Thr1 of the first wireless modem of the first wireless link and the handover threshold Thr2 of the second wireless modem of the second wireless link have been described as being different, they may of course be the same.

[0135] The correspondence information for managing transmission permission for each wireless modem, which is predetermined for each section LID of the road shown in Fig. 10, may be updated as appropriate based on handover log information that is kept in the wireless base station or wireless modem as a record of actual handover execution. The wireless base station or wireless modem that stores the log information functions as a log storage unit.

[0136] (Effects of the embodiment) 10, communication by the second wireless modem 102-2 can be permitted or prohibited depending on the position of the manned vehicle 20 or the unmanned dump truck 10, thereby prohibiting communication by the second wireless modem 102-2 in locations other than the handover sections LID004 and LID008 and the dumping site LID001. As a result, even if multiple wireless modems are provided to make the system redundant in order to eliminate handover failures, it is possible to prevent an increase in the communication load caused by the wireless modems.

[0137] Furthermore, by setting the location information of the correspondence information shown in FIG. 10 as a ranged section or area, it is possible to prohibit or permit communication of the wireless modem on a section-by-section or area-by-area basis.

[0138] The correspondence information shown in FIG. 10 may be stored in the vehicle-mounted terminals 2 and 3, or may be obtained from the server device (control center 30).

[0139] Furthermore, by appropriately updating the correspondence information based on the handover log information, it becomes possible to adjust the correspondence information in accordance with the hangover history.

[0140] In addition, by using the correspondence information shown in Figure 10(a), which associates vehicle location information (#), permission / prohibition information (RID002) that permits or prohibits communication by the second wireless modem 102-2, and other permission / prohibition information (RID001) that permits or prohibits communication by the first wireless modem 102-1, it is possible to control whether to permit or prohibit communication by both the first wireless modem 102-1 and the second wireless modem 102-2.

[0141] The present invention is not limited to the above-described embodiments and includes various modifications. For example, the above-described embodiments have been described in detail to clearly explain the present invention, and are not necessarily limited to those including all of the described configurations. Furthermore, part of the configuration of one embodiment can be replaced with the configuration of another embodiment, or the configuration of another embodiment can be added to the configuration of one embodiment. Furthermore, part of the configuration of each embodiment can be added, deleted, or replaced with other configurations. Furthermore, the above-described configurations, functions, processing units, processing means, etc. may be implemented in hardware, in part or in whole, by designing, for example, an integrated circuit. Furthermore, the above-described configurations, functions, etc. may be implemented in software, by a processor interpreting and executing a program that realizes each function. Information such as programs, tables, and files that realize each function can be stored in memory, a recording device such as a hard disk or SSD (Solid State Drive), or a recording medium such as an IC card, SD card, or DVD. [Explanation of symbols]

[0142] 1...Portable terminal, 2...In-vehicle terminal, 3...In-vehicle terminal, 4...Wireless base station, 5...Control tower, 10...Unmanned dump truck (autonomous vehicle), 20...Manned vehicle, 30...Control center, 31...Vehicle control management device, 32...Emergency stop input device, 33...Wired line, 100...Travel path, 101...Transmitting and receiving antenna, 102...Wireless modem, 103...Microcomputer device (control unit), 104...External I / F, 105...Power supply unit, 106...Display device, 107...Emergency stop button, 108...GPS receiver, 109...GPS antenna, 121, 321, 421...Wireless communication layer, 122, 322, 422...Communication permission layer, 123, 323, 423...Safety communication layer, 124, 324, 424...Application layer, 200...loading area, 300...discharge area, 500...wireless backhaul line, 510...downstream wireless line, 520...upstream wireless line, 801...CPU, 802...storage device, 810...battery, 811...voltage converter, 1000...vehicle control system

Claims

1. an on-board terminal mounted on a vehicle and having a first wireless modem for communicating with a base station via a first wireless line and a second wireless modem for communicating with the base station via a second wireless line; a server device that communicates with the vehicle-mounted terminal via the base station; a storage unit that stores correspondence information in which vehicle position information is associated with permission / prohibition information that permits or prohibits communication between at least one of the first wireless modem and the second wireless modem; a control unit that controls, based on the correspondence information stored in the storage unit, a state in which communication with only one of the first wireless modem and the second wireless modem is permitted, and a state in which communication with both the first wireless modem and the second wireless modem is permitted, depending on the location of the vehicle; the correspondence information includes location information at which a handover occurs to switch a base station that communicates with the first wireless modem or the second wireless modem, The control unit when the vehicle is traveling in a position where communication of only one of the first wireless modem and the second wireless modem is permitted, allowing only the one wireless modem to communicate with the base station and prohibiting communication of the other wireless modem with the base station; when the vehicle is traveling at a location where the handover occurs, permitting communication between both the first wireless modem and the second wireless modem and causing both the first wireless modem and the second wireless modem to communicate with the base station; The correspondence information is information in which the vehicle location information, permission / prohibition information for permitting or prohibiting communication of the second wireless modem, and other permission / prohibition information for permitting or prohibiting communication of the first wireless modem are associated with each other. A vehicle control system comprising:

2. 2. The vehicle control system according to claim 1, wherein the vehicle position information is a range of a section or area.

3. 3. The vehicle control system according to claim 2, wherein the storage unit for storing the correspondence information is installed in the vehicle-mounted terminal.

4. 3. The vehicle control system of claim 2, wherein the memory unit that stores the correspondence information is mounted on the server device, and the correspondence information is transmitted from the server device to the vehicle-mounted terminal via the base station.

5. 5. The vehicle control system of claim 4, further comprising a log memory unit that stores log information of handovers that switch base stations that communicate with the first wireless modem and the second wireless modem, and the correspondence information is updated based on the log information.

6. a first wireless modem that communicates with a base station over a first wireless link; a second wireless modem communicating with the base station over a second wireless link; a storage unit that stores correspondence information in which vehicle position information is associated with permission / prohibition information that permits or prohibits communication between at least one of the first wireless modem and the second wireless modem; a control unit that controls, based on the correspondence information stored in the storage unit, a state in which communication with only one of the first wireless modem and the second wireless modem is permitted, and a state in which communication with both the first wireless modem and the second wireless modem is permitted, depending on the location of the vehicle; the correspondence information includes location information at which a handover occurs to switch a base station that communicates with the first wireless modem or the second wireless modem, The control unit when the vehicle is traveling in a position where communication of only one of the first wireless modem and the second wireless modem is permitted, allowing only the one wireless modem to communicate with the base station and prohibiting communication of the other wireless modem with the base station; when the vehicle is traveling at a location where the handover occurs, permitting communication between both the first wireless modem and the second wireless modem and causing both the first wireless modem and the second wireless modem to communicate with the base station; The correspondence information is information in which the vehicle location information, permission / prohibition information for permitting or prohibiting communication of the second wireless modem, and other permission / prohibition information for permitting or prohibiting communication of the first wireless modem are associated with each other. A vehicle characterized by:

7. 7. The vehicle according to claim 6, wherein the vehicle location information is a range of a section or area.

8. 8. The vehicle according to claim 7, wherein the vehicle is capable of communicating with a server device via the base station, The vehicle is characterized in that the correspondence information is transmitted from the server device to the vehicle via the base station and stored in the storage unit.

9. In the vehicle of claim 6, the correspondence information is information that corresponds location information at which a handover occurs to switch the base station that communicates with the first wireless modem or the second wireless modem, and permission information that permits communication of the second wireless modem.

Images