JP2014090376A - Radio communication system, radio communication method, mobile station, program and recording medium - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent communication interruption between a mobile station and another station.SOLUTION: A radio communication system includes a mobile station 110 provided in a mobile V and another station 130 performing radio communication with the mobile station 110. The mobile station 110 includes: a communication interruption determination unit for determining whether or not communication interruption may possibly occur in the proceeding direction of the mobile V; and a radio communication method change unit for changing a radio communication method in order to maintain a connection when the communication interruption determination unit determines that communication interruption may occur in the proceeding direction of the mobile V.

Description

  The present invention relates to a wireless communication system, a wireless communication method, a mobile station, a program, and a recording medium. In particular, the present invention relates to a wireless communication system, a wireless communication method, a mobile station that is provided in a mobile body and performs wireless communication with another station, and a program that causes a computer to function as the mobile station. And a recording medium on which the program is recorded.

  When the mobile station is outdoors in mobile communication, the reception level fluctuates in place due to shielding by buildings around the mobile station. This spatial variation is called shadowing.

  Further, since the reception voltage when a plurality of radio waves are received is obtained by phase-combining the complex voltages of the radio waves, fluctuation occurs when the phase of each radio wave changes.

  Various techniques relating to such a background are known (see, for example, Patent Document 1).

  For example, Patent Literature 1 describes a technique for communicating with a communication device mounted on a mobile object existing in a communication area. More specifically, this technology acquires information related to the size of the moving object existing in the communication area. And this technique estimates the position of the mobile body which exists in a communication area | region. This technique predicts the occurrence of shadowing for communication with each mobile unit based on the size of each mobile unit and the predicted position. Then, when the prediction result that the occurrence of shadowing is predicted is obtained, this technology is compared with the mobile body in which the occurrence of shadowing is predicted, with respect to the antenna of the communication device mounted on the mobile body. Send control data to adjust the height. In this way, depending on this technology, it is possible to predict in advance the shadowing that occurs due to the positional relationship between mobile objects, and to prevent deterioration in communication quality.

Japanese Patent No. 3589896

  Since the technique described in Patent Document 1 is to prevent the occurrence of shadowing by adjusting the height of the antenna, shadowing caused by obstacles with relatively low heights, such as parallel running vehicles, is used. It can only respond. Therefore, depending on the technique described in Patent Document 1, the occurrence of shadowing due to an obstacle such as a high building cannot be prevented, and communication may be interrupted.

  In order to solve the above-described problem, according to a first aspect of the present invention, a wireless communication system for preventing communication interruption between a mobile station and another station, the mobile station provided in the mobile body, the mobile station, The mobile station is equipped with a communication station that performs wireless communication, and the mobile station communicates with a communication interruption determination unit that determines whether or not communication interruption may occur in the traveling direction of the mobile object, and communication communication that may occur in the traveling direction of the mobile object. And a wireless communication system change unit that changes the wireless communication system to maintain the connection when the interruption determination unit determines.

  The mobile station further includes a position information storage unit that stores information on a position where communication interruption may occur, and the communication interruption determination unit refers to the information stored in the position information storage unit in the traveling direction of the mobile object. It may be determined whether a communication interruption can occur.

  The mobile station further includes a sensor that detects an obstacle, and the mobile station determines a position at which communication interruption may occur due to the obstacle based on the positional relationship between the obstacle detected by the sensor and the other station. A position calculation unit for calculating may further be provided, and the position information storage unit may store information on the position calculated by the position calculation unit.

  The mobile station further includes a reception level determination unit that determines whether or not the reception level has become equal to or less than a threshold value for a predetermined time or more, and the position information storage unit has the reception level continuously for a predetermined time or more. When the reception level determination unit determines that the value is equal to or lower than the threshold value, information on the current position of the mobile object may be stored.

  The mobile station further includes a position data receiving unit that receives data indicating information on a position at which communication interruption may occur, transmitted from another station that is another mobile station, and the position information storage unit includes a position data receiving unit. Information on a position indicated by data received by the unit may be stored.

  The server further includes a server that is communicably connected to the mobile station via a communication line, and the server detects a change in an obstacle based on two images obtained by observing the same position on the ground from the sky at different timings. When the obstacle change detection unit and the obstacle change detection unit detect a change in the obstacle, based on the positional relationship between the obstacle and another station, a position where communication interruption due to the change in the obstacle can occur. A position change detection unit that detects changes in the position information, and the position information storage unit may store information on the position after the change detected by the position change detection unit.

  According to a second aspect of the present invention, there is provided a wireless communication method for preventing communication interruption between a mobile station provided in a mobile body and another station that performs wireless communication with the mobile station, in the traveling direction of the mobile body The wireless communication method is changed to maintain the connection when it is determined in the communication disruption determination stage that determines whether communication disruption can occur or in the communication disruption determination stage that communication disruption can occur in the traveling direction of the moving object. A wireless communication system change stage.

  According to the third aspect of the present invention, a mobile station that is provided in a mobile body and performs wireless communication with another station, and determines whether or not communication can be interrupted in the traveling direction of the mobile body. And a wireless communication method change unit that changes the wireless communication method to maintain the connection when the communication interruption determination unit determines that communication interruption may occur in the traveling direction of the mobile object.

  According to a fourth aspect of the present invention, there is provided a program for causing a computer to function as a mobile station that is provided in a mobile body and performs wireless communication with other stations, and communication interruption occurs in the traveling direction of the mobile body. A communication interruption determination unit that determines whether or not to obtain a wireless communication method change unit that changes a wireless communication method to maintain a connection when the communication interruption determination unit determines that a communication interruption may occur in the moving direction of the moving object To function as.

  According to a fifth aspect of the present invention, there is provided a recording medium that is provided in a mobile body and records a program that causes the computer to function as a mobile station that performs wireless communication with other stations. A communication interruption determination unit that determines whether or not communication interruption can occur in the mobile station, and changes the wireless communication method to maintain the connection when the communication interruption determination unit determines that communication interruption may occur in the traveling direction of the mobile object A program to function as a wireless communication system changing unit was recorded.

  The above summary of the invention does not enumerate all necessary features of the present invention. Also, a sub-combination of these feature groups can also be an invention.

  As is clear from the above description, according to the present invention, it is possible to prevent communication interruption due to the influence of shadowing due to the obstacle, for example, regardless of the height of the obstacle.

It is a figure which shows an example of the utilization environment of the radio | wireless communications system 100 which concerns on 1st Embodiment. 2 is a diagram illustrating an example of a block configuration of a mobile station 110. FIG. It is a figure which shows an example of the information stored in the positional information storage part 119 in a table format. FIG. 3 is a diagram illustrating an example of an operation flow of a mobile station 110. It is a figure which shows an example of the utilization environment of the radio | wireless communications system 200 which concerns on 2nd Embodiment. FIG. 3 is a diagram illustrating an example of a block configuration of a mobile station 210. It is a figure which shows an example of the information stored in the positional information storage part 219 in a table format. FIG. 3 is a diagram illustrating an example of an operation flow of a mobile station 210. It is a figure which shows an example of the utilization environment of the radio | wireless communications system 300 which concerns on 3rd Embodiment. FIG. 3 is a diagram illustrating an example of a block configuration of a mobile station 310. FIG. 3 is a diagram illustrating an example of an operation flow of a mobile station 310. It is a figure which shows an example of the utilization environment of the radio | wireless communications system 400 which concerns on 4th Embodiment. FIG. 3 is a diagram illustrating an example of a block configuration of a mobile station 410. FIG. 4 is a diagram illustrating an example of an operation flow of a mobile station 410. It is a figure which shows an example of the utilization environment of the radio | wireless communications system 500 which concerns on 5th Embodiment. It is a figure which shows an example of the block configuration of the mobile station 510a. It is a figure which shows an example of the operation | movement sequence of the mobile station 510a, the mobile station 510b, and the mobile station 510c. It is a figure which shows an example of the utilization environment of the radio | wireless communications system 600 which concerns on 6th Embodiment. FIG. 3 is a diagram illustrating an example of a block configuration of a mobile station 610. 3 is a diagram illustrating an example of a block configuration of a server 670. FIG. It is a figure which shows an example of the operation | movement sequence of an artificial satellite, the server 670, and the mobile station 610. It is a figure which shows an example of the hardware constitutions of the computer 800 which comprises the mobile station 110, 210, 310, 410, 510, 610 and the server 670 which concern on this embodiment.

  Hereinafter, the present invention will be described through embodiments of the invention. However, the following embodiments do not limit the claimed invention, and all combinations of features described in the embodiments are described below. However, this is not always essential for the solution of the invention.

  FIG. 1 shows an example of a usage environment of a wireless communication system 100 according to the first embodiment. The wireless communication system 100 is a system that prevents communication interruption between a mobile station and a base station.

  The wireless communication system 100 includes a mobile station 110 and a plurality of base stations 130a, a base station 130b, a base station 130c,... (Hereinafter collectively referred to as a base station 130). The base station 130 may be an example of “another station” in the present invention.

  The mobile station 110 is a moving radio station. For example, the mobile station 110 is provided in the unmanned vehicle V. Here, the unmanned vehicle V is a vehicle used for various operations such as reconnaissance, transportation of cargo, disposal of explosives, transportation, and the like. The mobile station 110 is electrically connected to, for example, a GPS (Global Positioning System) receiver, a vehicle speed sensor, a gyroscope, and a vehicle control device. Here, the GPS receiver is a device that measures the current position by, for example, receiving radio waves from a plurality of GPS satellites and determining the distance from each. The vehicle speed sensor is a device that measures the vehicle speed from the number of rotations of a tire, for example. The gyro is a device that detects, for example, the turning direction and amount. The vehicle control device is a device that controls the unmanned vehicle V, for example. For example, when receiving input of operation data indicating the operation content of the unmanned vehicle V, the vehicle control device controls the unmanned vehicle V based on the operation data. In addition, the vehicle control device outputs vehicle data indicating the state of the unmanned vehicle V, for example. The unmanned vehicle V may be an example of the “moving body” in the present invention.

  Base station 130 is a radio station for communicating with mobile station 110. For example, each base station 130 is provided at a predetermined position on land. Base station 130 is wirelessly connected to mobile station 110. The base station 130 is communicatively connected to the operation terminal C via the communication line N. Here, the operation terminal C is a terminal for remotely operating the unmanned vehicle V. When the base station 130 receives the operation data transmitted from the operation terminal C, the base station 130 transmits the operation data to the mobile station 110. Further, when the base station 130 receives the vehicle data transmitted from the mobile station 110, the base station 130 transmits the vehicle data to the operation terminal C.

  Here, it is assumed that there is a place Ea around the obstacle B such as a building where communication with the base station 130a may be interrupted. Similarly, it is assumed that there is a place Eb around the obstacle B such as a building where communication with the base station 130b may be interrupted.

  In the present embodiment, a configuration in which the wireless communication system 100 includes one mobile station 110 will be described for the purpose of preventing the description from becoming complicated. However, the wireless communication system 100 may include a plurality of mobile stations 110.

  FIG. 2 shows an example of a block configuration of the mobile station 110. The mobile station 110 includes a data transmission / reception unit 111, a data input / output unit 112, a current position data input reception unit 113, a vehicle speed data input reception unit 114, a gyro data input reception unit 115, a communication interruption determination unit 116, and a wireless communication system change unit 117. , A digital map storage unit 118, and a position information storage unit 119. In the following description, the function and operation of each component will be described in detail.

  The data transmitter / receiver 111 transmits the vehicle data output from the vehicle control device to the operation terminal C via the base station 130. Further, the data transmission / reception unit 111 receives operation data transmitted from the operation terminal C via the base station 130.

  The data input / output unit 112 receives input of vehicle data output from the vehicle control device. Further, the data input / output unit 112 outputs the operation data transmitted from the operation terminal C to the vehicle control device.

  The current position data input accepting unit 113 accepts input of data indicating the current position of the unmanned vehicle V.

  The vehicle speed data input receiving unit 114 receives input of data indicating the vehicle speed of the unmanned vehicle V.

  The gyro data input receiving unit 115 receives input of data indicating the turning direction and amount of the unmanned vehicle V.

  The communication interruption determination unit 116 determines whether communication interruption can occur in the traveling direction D of the unmanned vehicle V. For example, the communication interruption determination unit 116 determines whether communication interruption can occur in the traveling direction D of the unmanned vehicle V with reference to information stored in the position information storage unit 119.

  The wireless communication method change unit 117 changes the wireless communication method to maintain the connection when the communication interruption determination unit 116 determines that communication interruption may occur in the traveling direction D of the unmanned vehicle V.

  The digital map storage unit 118 stores a digital map. Here, the digital map is a map that can be computerized and computerized.

  The position information storage unit 119 stores information on positions where communication interruption may occur.

  FIG. 3 shows an example of information stored in the position information storage unit 119 in a table format. In the position information storage unit 119, information on a base station ID (identifier) and geographic coordinates (latitude, longitude) are stored in association with each other.

  The base station ID information is an identification code for uniquely identifying each base station 130. In the following description, the base station 130 identified by the base station ID “130a” is referred to as a base station 130a.

  The information on the geographical coordinates (latitude, longitude) is information indicating coordinates on the earth where the communication with the base station 130 identified by the base station ID may be interrupted. For example, in this example, the position where communication interruption with the base station 130a may occur is the geographical coordinates (lat1, lng1) periphery (Ea).

  FIG. 4 shows an example of the operation flow of the mobile station 110. In the description of this operation flow, the case where the mobile station 110 performs wireless communication with the base station 130a will be described in detail. In the description of this operation flow, both FIGS. 1 to 3 are referred to.

  An operator of the unmanned vehicle V remotely operates the unmanned vehicle V using the operation terminal C. When the operation is performed by the operator, the operation terminal C transmits operation data indicating the operation content to the mobile station 110 via the base station 130a.

  When the data transmission / reception unit 111 of the mobile station 110 receives the operation data transmitted from the operation terminal C via the base station 130 a, the data transmission / reception unit 111 sends the operation data to the data input / output unit 112.

  When the data input / output unit 112 of the mobile station 110 receives the operation data transmitted from the data transmission / reception unit 111, the data input / output unit 112 outputs the operation data to the vehicle control device.

  When receiving the input of the operation data output from the mobile station 110, the vehicle control device controls the unmanned vehicle V according to the operation content indicated by the operation data.

  On the other hand, the vehicle control device outputs vehicle data indicating the state of the unmanned vehicle V to the mobile station 110 at predetermined time intervals, for example.

  When the data input / output unit 112 of the mobile station 110 receives the input of the vehicle data output from the vehicle control device, the data input / output unit 112 transmits the vehicle data to the data transmission / reception unit 111.

  When the data transmission / reception unit 111 of the mobile station 110 receives the vehicle data transmitted from the data input / output unit 112, the data transmission / reception unit 111 transmits the vehicle data to the operation terminal C via the base station 130a.

  When the operation terminal C receives the vehicle data transmitted from the mobile station 110 via the base station 130a, the operation terminal C outputs information on the state of the unmanned vehicle V indicated by the vehicle data.

  In this manner, the operator of the unmanned vehicle V performs remote operation of the unmanned vehicle V while confirming the state of the unmanned vehicle V.

  On the other hand, when the unmanned vehicle V is activated, the GPS receiver starts measuring the current position of the unmanned vehicle V. The GPS receiver then repeatedly outputs data indicating the measured current position to the mobile station 110 over time.

  Similarly, when the unmanned vehicle V is activated, the vehicle speed sensor starts measuring the vehicle speed of the unmanned vehicle V. The vehicle speed sensor then repeatedly outputs data indicating the measured vehicle speed to the mobile station 110 over time.

  Similarly, when the unmanned vehicle V is activated, the gyro starts detecting the turning direction and amount of the unmanned vehicle V. Then, the gyro repeatedly outputs data indicating the detected turning direction and amount to the mobile station 110 over time.

  When receiving the input of data output from the GPS receiver (S101), the current position data input receiving unit 113 of the mobile station 110 sends the data to the communication interruption determining unit 116.

  Similarly, when the vehicle speed data input acceptance unit 114 of the mobile station 110 accepts input of data output from the vehicle speed sensor (S102), the data is sent to the communication interruption determination unit 116.

  Similarly, when the gyro data input accepting unit 115 of the mobile station 110 accepts the input of data output from the gyro (S103), the gyro data input accepting unit 115 sends the data to the communication disruption determining unit 116.

  When the communication interruption determination unit 116 of the mobile station 110 receives the data sent from the current position data input reception unit 113, the vehicle speed data input reception unit 114, and the gyro data input reception unit 115, the respective data indicated by these data are received. Based on the information, the digital map stored in the digital map storage unit 118, and the information stored in the position information storage unit 119, it is determined whether or not communication interruption may occur in the traveling direction D of the unmanned vehicle V. Determine (S104). For example, first, the communication interruption determination unit 116 specifies the traveling direction D of the unmanned vehicle V on the digital map based on the current position of the unmanned vehicle V and the turning direction and amount. Then, the communication interruption determination unit 116 reads out the geographical coordinates (lat1, lng1) indicating the position where the communication interruption with the communicating base station 130a may occur among the information stored in the position information storage unit 119. Then, the communication interruption determination unit 116 determines whether or not the unmanned vehicle V passes through the vicinity (Ea) of the geographical coordinates (lat1, lng1) based on the identified traveling direction D of the unmanned vehicle V. As a result, when the unmanned vehicle V does not pass the geographical coordinates “(lat1, lng1) vicinity (Ea), the communication interruption determination unit 116 determines that communication interruption cannot occur in the traveling direction D of the unmanned vehicle V (S104). On the other hand, when the unmanned vehicle V passes the geographic coordinates (lat1, lng1) and the vicinity (Ea), the communication interruption determination unit 116 determines that the unmanned vehicle V is in the geographic coordinates (lat1) based on the vehicle speed of the unmanned vehicle V. , Lng1) The passage time required to pass the vicinity (Ea) is calculated, and if the passage time is within an allowable time during which no communication interruption occurs, the communication interruption determination unit 116 proceeds the unmanned vehicle V. It is determined that no communication interruption can occur in the direction D. (S104: No) On the other hand, if the passing time is not within an allowable time during which communication interruption does not occur, the communication interruption determination unit 116. Determines that communication interruption can occur in the traveling direction D of the unmanned vehicle V. (S104: Yes) Then, the communication interruption determining unit 116, the data indicating the judgment result, and sends to the wireless communication method changing unit 117.

  When the wireless communication method changing unit 117 of the mobile station 110 receives the data transmitted from the communication interruption determination unit 116, the determination result indicated by the data indicates that communication interruption cannot occur in the traveling direction D of the unmanned vehicle V. If it is the determination result, no processing is performed. On the other hand, when the determination result indicated by the data received from the communication interruption determination unit 116 is a determination result that communication interruption may occur in the traveling direction D of the unmanned vehicle V, the wireless communication method change unit 117 maintains the connection. The wireless communication system is changed as appropriate (S105). For example, the wireless communication scheme change unit 117 changes the subcarrier modulation scheme to maintain the connection. Further, for example, the radio communication scheme changing unit 117 lowers the modulation rate of the subcarrier to maintain the connection. In addition, for example, the wireless communication scheme change unit 117 transmits the same data using a plurality of subcarriers to maintain the connection, and provides redundancy to the data. For example, the wireless communication system change unit 117 increases the guard interval to maintain the connection and improves the interference resistance.

  As described above, the wireless communication system 100 includes the mobile station 110 provided in the unmanned vehicle V. The radio communication system 100 also includes a base station 130 that performs radio communication with the mobile station 110. Then, the mobile station 110 determines whether communication interruption can occur in the traveling direction D of the unmanned vehicle V. When the mobile station 110 determines that a communication interruption can occur in the traveling direction D of the unmanned vehicle V, the mobile station 110 changes the wireless communication method to maintain the connection.

  In this way, depending on the radio communication system 100, for example, it is possible to prevent communication interruption due to the influence of shadowing or the like due to the obstacle regardless of the height of the obstacle.

  Further, as described above, the mobile station 110 stores information on a position where communication interruption may occur. Then, the mobile station 110 refers to the stored information and determines whether or not communication interruption can occur in the traveling direction D of the unmanned vehicle V.

  In this way, depending on the wireless communication system 100, for example, if information on positions where communication interruption may occur is collected in advance using a probe car or the like, a highly reliable system can be obtained.

  FIG. 5 shows an example of a usage environment of the wireless communication system 200 according to the second embodiment. The wireless communication system 200 is a system that prevents communication interruption between mobile stations.

  The wireless communication system 200 includes a mobile station 210 and a mobile station 250. The mobile station 250 may be an example of “another station” in the present invention.

  The mobile station 210 is a moving radio station. For example, the mobile station 210 is provided in the unmanned vehicle V. Here, the unmanned vehicle V is a vehicle used for various operations such as reconnaissance, transportation of cargo, disposal of explosives, transportation, and the like. The mobile station 210 is electrically connected to, for example, a GPS receiver, a vehicle speed sensor, a gyro, and a vehicle control device. The vehicle control device is a device that controls the unmanned vehicle V, for example. For example, when receiving input of operation data indicating the operation content of the unmanned vehicle V, the vehicle control device controls the unmanned vehicle V based on the operation data. In addition, the vehicle control device outputs vehicle data indicating the state of the unmanned vehicle V, for example. The unmanned vehicle V may be an example of the “moving body” in the present invention.

  The mobile station 250 is a moving radio station. For example, the mobile station 250 is provided in the vehicle MV. Here, the vehicle MV is a vehicle on which an operator of the unmanned vehicle V is boarded. The mobile station 250 is wirelessly connected to the mobile station 210. The mobile station 250 is electrically connected to the operation terminal and the GPS receiver. Here, the operation terminal is a terminal for remotely operating the unmanned vehicle V. When receiving the operation data output from the operation terminal, the mobile station 250 transmits the operation data to the mobile station 210. Further, when the mobile station 250 receives the vehicle data transmitted from the mobile station 210, the mobile station 250 outputs the vehicle data to the operation terminal. When the operation terminal receives input of current position data indicating the current position output from the GPS receiver, the operation terminal transmits the current position data to the mobile station 210.

  Here, it is assumed that there is a place Eb around the obstacle B such as a building where the communication with the mobile station 250b may be interrupted when the mobile station 250b is at the geographical coordinates Gb.

  In the present embodiment, a configuration in which the wireless communication system 200 includes one mobile station 210 and a mobile station 250 will be described for the purpose of preventing the description from becoming complicated. However, the wireless communication system 200 may include a plurality of mobile stations 210 and mobile stations 250.

  FIG. 6 shows an exemplary block configuration of the mobile station 210. The mobile station 210 includes a data transmission / reception unit 211, a data input / output unit 212, a current position data input reception unit 213, a vehicle speed data input reception unit 214, a gyro data input reception unit 215, a communication interruption determination unit 216, and a wireless communication method change unit 217. , A digital map storage unit 218, and a position information storage unit 219. In the following description, the function and operation of each component will be described in detail.

  The data transmitting / receiving unit 211 transmits the vehicle data output from the vehicle control device to the operation terminal via the mobile station 250. The data transmitter / receiver 211 receives operation data transmitted from the operation terminal via the mobile station 250. The data transmitter / receiver 211 receives current position data transmitted from the mobile station 250.

  The data input / output unit 212 receives input of vehicle data output from the vehicle control device. Further, the data input / output unit 212 outputs the operation data transmitted from the operation terminal to the vehicle control device.

  The current position data input reception unit 213 receives input of data indicating the current position of the unmanned vehicle V.

  The vehicle speed data input receiving unit 214 receives input of data indicating the vehicle speed of the unmanned vehicle V.

  The gyro data input receiving unit 215 receives input of data indicating the turning direction and amount of the unmanned vehicle V.

  The communication interruption determination unit 216 determines whether or not communication interruption can occur in the traveling direction D of the unmanned vehicle V. For example, the communication interruption determination unit 216 refers to the current position information of the mobile station 250 and the information stored in the position information storage unit 219 to determine whether or not communication interruption may occur in the traveling direction D of the unmanned vehicle V. Determine whether.

  The wireless communication system change unit 217 changes the wireless communication system to maintain the connection when the communication interruption determination unit 216 determines that communication interruption may occur in the traveling direction D of the unmanned vehicle V.

  The digital map storage unit 218 stores a digital map.

  The position information storage unit 219 stores information on positions where communication interruption may occur.

  FIG. 7 shows an example of information stored in the position information storage unit 219 in a table format. In the position information storage unit 219, information on geographical coordinates (latitude, longitude) of other stations and information on geographical coordinates (latitude, longitude) are stored in association with each other.

  The information on the geographical coordinates (latitude, longitude) of the other station is information indicating coordinates representing the position of the other station on the earth. Geographic coordinates (latitude and longitude) information indicates the location on the earth where communication with other stations may be disrupted when other stations are located in the geographical coordinates indicated by the geographical coordinates (latitude and longitude) information of other stations. It is the information which shows the coordinate to represent. For example, in this example, when the other station is in the geographical coordinates (lat12, lng12), the position where the communication interruption with the other station may occur is the vicinity of the geographical coordinates (lat1, lng1) (Eb). . In other words, for example, in this example, if the mobile station 250 is in the geographical coordinates (lat12, ng12) but the mobile station 210 is not in the vicinity of the geographical coordinates (lat2, lng2) (Eb), the mobile station 210 is This shows that no communication interruption occurs during communication with the mobile station 250. This is because the positional relationship between the mobile station 210 and the mobile station 250 is not constant because the vehicle MV moves freely by the rider's driving and the unmanned vehicle V moves by being remotely operated by the passenger of the vehicle MV. By changing according to the position of the unmanned vehicle V and the vehicle MV.

  FIG. 8 shows an example of an operation flow of the mobile station 210. In the description of this operation flow, the case where the mobile station 210 performs wireless communication with the mobile station 250 will be described in detail. In the description of this operation flow, FIGS. 5 to 7 will be referred to together.

  An operator of the unmanned vehicle V remotely operates the unmanned vehicle V using the operation terminal. When an operation is performed by the operator, the operation terminal transmits operation data indicating the operation content to the mobile station 210 via the mobile station 250.

  When the data transmission / reception unit 211 of the mobile station 210 receives the operation data transmitted from the operation terminal via the mobile station 250, the data transmission / reception unit 211 sends the operation data to the data input / output unit 212.

  When the data input / output unit 212 of the mobile station 210 receives the operation data transmitted from the data transmission / reception unit 211, the data input / output unit 212 outputs the operation data to the vehicle control device.

  When receiving the operation data output from the mobile station 210, the vehicle control device controls the unmanned vehicle V according to the operation content indicated by the operation data.

  On the other hand, the vehicle control device outputs vehicle data indicating the state of the unmanned vehicle V to the mobile station 210 at predetermined time intervals, for example.

  When the data input / output unit 212 of the mobile station 210 receives the input of the vehicle data output from the vehicle control device, the data input / output unit 212 transmits the vehicle data to the data transmission / reception unit 211.

  When the data transmission / reception unit 211 of the mobile station 210 receives the vehicle data transmitted from the data input / output unit 212, the data transmission / reception unit 211 transmits the vehicle data to the operation terminal via the mobile station 250.

  When the operation terminal receives the vehicle data transmitted from the mobile station 210 via the mobile station 250, the operation terminal outputs information on the state of the unmanned vehicle V indicated by the vehicle data.

  In this manner, the operator of the unmanned vehicle V performs remote operation of the unmanned vehicle V while confirming the state of the unmanned vehicle V.

  When the mobile station 250 starts wireless communication with the mobile station 210, the mobile station 250 repeatedly transmits the current position data output from the GPS receiver to the mobile station 210 over time.

  On the other hand, when the unmanned vehicle V is activated, the GPS receiver starts measuring the current position of the unmanned vehicle V. Then, the GPS receiver repeatedly outputs data indicating the measured current position to the mobile station 210 over time.

  Similarly, when the unmanned vehicle V is activated, the vehicle speed sensor starts measuring the vehicle speed of the unmanned vehicle V. The vehicle speed sensor then repeatedly outputs data indicating the measured vehicle speed to the mobile station 210 over time.

  Similarly, when the unmanned vehicle V is activated, the gyro starts detecting the turning direction and amount of the unmanned vehicle V. Then, the gyro repeatedly outputs data indicating the detected turning direction and amount to the mobile station 210 over time.

  When the data transmission / reception unit 211 of the mobile station 210 receives the current position data transmitted from the mobile station 250 (S206), the data transmission / reception unit 211 sends the current position data to the communication interruption determination unit 216.

  When receiving the input of the data output from the GPS receiver (S201), the current position data input receiving unit 213 of the mobile station 210 sends the data to the communication interruption determining unit 216.

  Similarly, when the vehicle speed data input reception unit 214 of the mobile station 210 receives the input of data output from the vehicle speed sensor (S202), the data is sent to the communication interruption determination unit 216.

  Similarly, when receiving the input of data output from the gyro (S203), the gyro data input receiving unit 215 of the mobile station 210 sends the data to the communication interruption determining unit 216.

  When the communication interruption determination unit 216 of the mobile station 210 receives the data transmitted from the data transmission / reception unit 211, the current position data input reception unit 213, the vehicle speed data input reception unit 214, and the gyro data input reception unit 215, respectively. Based on the information indicated by the data, the digital map stored in the digital map storage unit 218, and the information stored in the position information storage unit 219, communication interruption occurs in the traveling direction D of the unmanned vehicle V. It is determined whether or not to obtain (S204). For example, first, the communication interruption determination unit 216 matches or is close to the geographical coordinate of the current position of the mobile station 250 in the information of the geographical coordinates (latitude, longitude) of the other stations stored in the position information storage unit 219. Search for value information. As a result, if there is no corresponding value information, the communication disruption determination unit 216 determines that communication disruption cannot occur in the traveling direction D of the unmanned vehicle V (S204: No). On the other hand, when there is information of the corresponding value, the communication interruption determination unit 216 reads the geographical coordinates (latitude, longitude) indicating the position where the communication interruption may occur, stored in association with the information. Then, the communication disruption determination unit 216 specifies the traveling direction D of the unmanned vehicle V on the digital map based on the current position of the unmanned vehicle V, the turning direction and the amount. Then, the communication interruption determination unit 216 determines whether or not the unmanned vehicle V passes around the geographical coordinates (latitude, longitude) read from the position information storage unit 219 based on the specified traveling direction D of the unmanned vehicle V. judge. As a result, when the unmanned vehicle V does not pass around the read geographical coordinates (latitude, longitude), the communication interruption determination unit 216 determines that communication interruption cannot occur in the traveling direction D of the unmanned vehicle V (S204: No). On the other hand, when the unmanned vehicle V passes around the read geographic coordinates (latitude, longitude), the communication disruption determination unit 216 determines the surroundings of the read geographic coordinates (latitude, longitude) based on the vehicle speed of the unmanned vehicle V. The passing time required for the unmanned vehicle V to pass through is calculated. If the passage time is within an allowable time during which communication interruption does not occur, the communication interruption determination unit 216 determines that communication interruption cannot occur in the traveling direction D of the unmanned vehicle V (S204: No). On the other hand, if the passage time is not within an allowable time during which no communication interruption occurs, the communication interruption determination unit 216 determines that communication interruption may occur in the traveling direction D of the unmanned vehicle V (Yes in S204). Then, the communication interruption determination unit 216 sends data indicating the determination result to the wireless communication method change unit 217.

  When the wireless communication method changing unit 217 of the mobile station 210 receives the data transmitted from the communication interruption determination unit 216, the determination result indicated by the data indicates that communication interruption cannot occur in the traveling direction D of the unmanned vehicle V. If it is the determination result, no processing is performed. On the other hand, when the determination result indicated by the data received from the communication interruption determination unit 216 is a determination result that communication interruption may occur in the traveling direction D of the unmanned vehicle V, the wireless communication method change unit 217 maintains the connection. The wireless communication system is changed as appropriate (S205). For example, the wireless communication scheme change unit 217 changes the subcarrier modulation scheme to maintain the connection. Further, for example, the radio communication scheme changing unit 217 lowers the subcarrier modulation rate in order to maintain the connection. In addition, for example, the wireless communication scheme change unit 217 transmits the same data using a plurality of subcarriers to maintain the connection, and provides redundancy to the data. For example, the wireless communication system change unit 217 increases the guard interval so as to maintain the connection, and improves the interference resistance.

  As described above, the wireless communication system 200 includes the mobile station 210 provided in the unmanned vehicle V. The radio communication system 200 includes a mobile station 250 that performs radio communication with the mobile station 210. Then, the mobile station 210 determines whether communication interruption can occur in the traveling direction D of the unmanned vehicle V. When the mobile station 210 determines that communication interruption may occur in the traveling direction D of the unmanned vehicle V, the mobile station 210 changes the wireless communication method to maintain the connection.

  In this way, depending on the radio communication system 200, for example, it is possible to prevent communication interruption due to the influence of shadowing due to the obstacle regardless of the height of the obstacle.

  Further, as described above, the mobile station 210 stores information on a position where communication interruption may occur. Then, the mobile station 210 refers to the stored information and determines whether or not communication interruption can occur in the traveling direction D of the unmanned vehicle V.

  Thus, depending on the wireless communication system 200, for example, if information on positions where communication interruption may occur is collected in advance using a probe car or the like, a highly reliable system can be obtained.

  FIG. 9 shows an example of a usage environment of the wireless communication system 300 according to the third embodiment. The wireless communication system 300 is a system that prevents communication interruption between a mobile station and a base station.

  The wireless communication system 300 includes a mobile station 310 and a plurality of base stations 130.

  In addition, among the constituent elements of the wireless communication system 300, the constituent elements having the same names as those of the constituent elements of the wireless communication system 100 have the same functions and operations.

  The mobile station 310 is a moving radio station. For example, the mobile station 310 is provided in the unmanned vehicle V. The mobile station 310 is electrically connected to, for example, a GPS receiver, a vehicle speed sensor, a gyro, a vehicle control device, and a laser displacement sensor. Here, the laser displacement sensor is a sensor that detects an obstacle and measures a distance to the obstacle. For example, a laser displacement sensor is a system that applies triangulation, and is configured by a combination of a light emitting element and a light receiving element. The laser displacement sensor may be an example of the “sensor” in the present invention.

  Base station 130 is a radio station for communicating with mobile station 310. Base station 130 is wirelessly connected to mobile station 310. When the base station 130 receives the operation data transmitted from the operation terminal C, the base station 130 transmits the operation data to the mobile station 310. In addition, when the base station 130 receives the vehicle data transmitted from the mobile station 310, the base station 130 transmits the vehicle data to the operation terminal C.

  In the present embodiment, a configuration in which the wireless communication system 300 includes one mobile station 310 will be described for the purpose of preventing the description from becoming complicated. However, the wireless communication system 300 may include a plurality of mobile stations 310.

  FIG. 10 shows an example of a block configuration of the mobile station 310. The mobile station 310 includes a data transmission / reception unit 111, a data input / output unit 112, a current position data input reception unit 113, a vehicle speed data input reception unit 114, a gyro data input reception unit 115, a communication interruption determination unit 116, and a wireless communication method change unit 117. , A digital map storage unit 118, a position information storage unit 119, an obstacle data input reception unit 320, and a position calculation unit 321. In the following description, the function and operation of each component will be described in detail.

  In addition, among the constituent elements of the mobile station 310, constituent elements having the same names as those of the constituent elements of the mobile station 110 have the same functions and operations.

  The obstacle data input receiving unit 320 receives an input of data indicating the distance to the obstacle output from the laser displacement sensor.

  Based on the positional relationship between the obstacle detected by the laser displacement sensor and the base station 130, the position calculation unit 321 calculates a position where communication interruption may occur due to the obstacle.

  FIG. 11 shows an example of an operation flow of the mobile station 310. In the description of this operation flow, the operation of the mobile station 310 when the laser displacement sensor detects an obstacle will be described in detail. In the description of this operation flow, both FIGS.

  When the unmanned vehicle V is activated, the GPS receiver starts measuring the current position of the unmanned vehicle V. Then, the GPS receiver repeatedly outputs data indicating the measured current position to the mobile station 310 over time.

  Each time the current position data input receiving unit 113 of the mobile station 310 receives input of data output from the GPS receiver (S301), the data is sent to the position calculating unit 321.

  Further, when the unmanned vehicle V is activated, the laser displacement sensor starts to detect an obstacle. When the laser displacement sensor detects the obstacle B, it measures the distance to the obstacle B. The laser displacement sensor outputs data indicating the distance to the mobile station 310.

  When the obstacle data input accepting unit 320 of the mobile station 310 accepts input of data output from the laser displacement sensor (S302), it sends the data to the position calculating unit 321.

  The position calculation unit 321 of the mobile station 310 sequentially receives data transmitted from the current position data input reception unit 113. When the position calculation unit 321 receives the data sent from the obstacle data input reception unit 320, the position calculation unit 321 finally receives the information on the distance to the obstacle B indicated by the data and the current position data input reception unit 113. Based on the current position information of the unmanned vehicle V indicated by the received data and the position information of the base station 130, a position where communication interruption may occur due to the obstacle B detected by the laser displacement sensor is calculated (S303). . For example, first, the position calculation unit 321 calculates the geographical coordinates of the position of the obstacle B based on the geographical coordinates of the current position of the unmanned vehicle V and the distance to the obstacle B. Then, the position calculating unit 321 is a position where shadowing and fading are likely to occur around the obstacle B based on the geographical coordinates of the position of the obstacle B and the geographical coordinates of the position of the base station 130. Is calculated as a position where communication interruption with the base station 130 may occur. Then, the position calculation unit 321 stores the information in the position information storage unit 119 (S304).

  As described above, the wireless communication system 300 further includes the laser displacement sensor that is provided in the unmanned vehicle V and detects the obstacle B. Then, based on the positional relationship between the obstacle B detected by the laser displacement sensor and the base station 130, the mobile station 310 calculates a position where communication interruption can occur due to the obstacle B. Then, the mobile station 310 stores the calculated position information.

  In this way, depending on the wireless communication system 300, when an obstacle such as a building is newly constructed, or when a building or the like collapses due to a disaster or the like, an obstacle in a rubble mountain is created. It is possible to prevent communication interruptions caused by things.

  FIG. 12 shows an example of a usage environment of the wireless communication system 400 according to the fourth embodiment. The wireless communication system 400 is a system that prevents communication interruption between a mobile station and a base station.

  The wireless communication system 400 includes a mobile station 410 and a plurality of base stations 130.

  In addition, among the constituent elements of the wireless communication system 400, constituent elements having the same names and denoted by the same reference numerals as the constituent elements of the wireless communication system 100 show similar functions and operations.

  The mobile station 410 is a moving radio station. For example, the mobile station 410 is provided in the unmanned vehicle V. The mobile station 410 is electrically connected to, for example, a GPS receiver, a vehicle speed sensor, a gyro, and a vehicle control device.

  Base station 130 is a radio station for communicating with mobile station 410. Base station 130 is wirelessly connected to mobile station 410. When the base station 130 receives the operation data transmitted from the operation terminal C, the base station 130 transmits the operation data to the mobile station 410. In addition, when the base station 130 receives the vehicle data transmitted from the mobile station 410, the base station 130 transmits the vehicle data to the operation terminal C.

  In the present embodiment, a configuration in which the wireless communication system 400 includes one mobile station 410 will be described for the purpose of preventing the description from becoming complicated. However, the wireless communication system 400 may include a plurality of mobile stations 410.

  FIG. 13 shows an exemplary block configuration of the mobile station 410. The mobile station 410 includes a data transmission / reception unit 111, a data input / output unit 112, a current position data input reception unit 113, a vehicle speed data input reception unit 114, a gyro data input reception unit 115, a communication interruption determination unit 116, and a wireless communication method change unit 117. , A digital map storage unit 118, a location information storage unit 119, and a reception level determination unit 422. In the following description, the function and operation of each component will be described in detail.

  In addition, among the constituent elements of the mobile station 410, constituent elements having the same names as those of the constituent elements of the mobile station 110 have the same functions and operations.

  The reception level determination unit 422 determines whether or not the reception level has become equal to or lower than a threshold value continuously for a predetermined time or more.

  FIG. 14 shows an example of an operation flow of the mobile station 410. In this operation flow, the operation of the mobile station 410 when updating information on a position where communication interruption may occur is described in detail according to the reception level. In the description of this operation flow, both FIGS.

  When the unmanned vehicle V is activated, the GPS receiver starts measuring the current position of the unmanned vehicle V. Then, the GPS receiver repeatedly outputs data indicating the measured current position to the mobile station 410 over time.

  The current position data input acceptance unit 113 of the mobile station 410 accepts input of data output from the GPS receiver (S401).

  On the other hand, when the communication with the base station 130 is started, the reception level determination unit 422 of the mobile station 410 starts monitoring the reception level, and whether or not the reception level continuously falls below the threshold value for a predetermined time or more. Is determined (S402). For example, the predetermined time serving as a reference for determination by the reception level determination unit 422 is a time when communication interruption may occur when the reception level is equal to or lower than a threshold value and continues for that time or longer. If the reception level determination unit 422 determines that the reception level has become equal to or lower than the threshold value for a predetermined time or longer (S402), the reception level determination unit 422 sends data to that effect to the current position data input reception unit 113.

  When receiving the data sent from the reception level determination unit 422, the current position data input reception unit 113 of the mobile station 410 uses the current position indicated by the latest data received from the GPS receiver at that time as a reference. The position is stored in the position information storage unit 119 as information on a position where communication interruption with the base station 130 may occur (S403).

  As described above, the mobile station 410 determines whether or not the reception level is equal to or lower than the threshold value continuously for a predetermined time or more. Then, the mobile station 410 stores information on the current position of the unmanned vehicle V when it is determined that the reception level is continuously below the threshold value for a predetermined time or longer.

  In this way, depending on the wireless communication system 400, when an obstacle such as a building is newly constructed, or when a building or the like collapses due to a disaster or the like, an obstacle of a rubble mountain is created, etc. It is possible to prevent communication interruptions caused by things.

  FIG. 15 shows an example of a usage environment of a wireless communication system 500 according to the fifth embodiment. The wireless communication system 500 is a system that prevents communication interruption between mobile stations.

  The wireless communication system 500 includes a plurality of mobile stations 510a, mobile stations 510b, mobile stations 510c,... (Hereinafter collectively referred to as mobile stations 510). Further, another mobile station 510 for one mobile station 510 may be an example of “another station” in the present invention.

  The mobile station 510 is a moving radio station. For example, the mobile station 510 is provided in each of the unmanned vehicle Va, unmanned vehicle Vb, unmanned vehicle Vc,... (Hereinafter collectively referred to as unmanned vehicle V). The mobile station 510 is electrically connected to, for example, a GPS receiver, a vehicle speed sensor, a gyro, a laser displacement sensor, and a vehicle control device. The mobile station 510 is connected to another mobile station 510 by wireless communication.

  FIG. 16 shows an example of a block configuration of the mobile station 510a. The mobile station 510a includes a data transmission / reception unit 511a, a data input / output unit 512a, a current position data input reception unit 113a, a vehicle speed data input reception unit 114a, a gyro data input reception unit 115a, a communication interruption determination unit 116a, and a wireless communication system change unit 117a. , A digital map storage unit 118a, a location information storage unit 119a, an obstacle data input reception unit 320a, a location calculation unit 321a, and a location data transmission / reception unit 523a. In the following description, the function and operation of each component will be described in detail. The position data transmitting / receiving unit 523 may be an example of the “position data receiving unit” in the present invention.

  In addition, the mobile station 510b other than the mobile station 510a, the mobile station 510c,... Have the same components as the components of the mobile station 510a. In the following description, when distinguishing which mobile station 510 is a constituent element of the mobile station 510, the same subscripts (a, b, c) as the mobile station 510 having each constituent element are used. ,...) Are added to the end of each component to distinguish them. For example, the data transmission / reception unit 511a, the data transmission / reception unit 511b, and the data transmission / reception unit 511c are components of the mobile station 510a, the mobile station 510b, and the mobile station 510c, respectively.

  Further, in the following description, the function and operation of a component that is not given a subscript indicate the function and operation of any component that is assigned the same reference numeral. For example, the functions and operations described in the data transmitting / receiving unit 511 indicate the functions and operations of the data transmitting / receiving unit 511a, the data transmitting / receiving unit 511b, the data transmitting / receiving unit 511c,.

  In addition, among the components of the mobile station 510, components having the same names that are assigned the same reference numerals as those of the mobile stations 110 and 310 show similar functions and operations.

  The data transmission / reception unit 511 transmits the vehicle data output from the vehicle control device to another mobile station 510. The data transmitter / receiver 511 receives vehicle data transmitted from another mobile station 510.

  The data input / output unit 512 receives input of vehicle data output from the vehicle control device. Further, the data input / output unit 512 outputs the vehicle data transmitted from the other mobile station 510 to the vehicle control device.

  The position data transmission / reception unit 523 transmits data indicating information on a position where communication interruption may occur to another mobile station 510. In addition, the position data transmission / reception unit 523 receives data indicating information on a position where communication interruption may occur, transmitted from another mobile station 510.

  FIG. 17 shows an example of an operation sequence of the mobile station 510a, the mobile station 510b, and the mobile station 510c. In this operation sequence, the operations of the mobile station 510a, the mobile station 510b, and the mobile station 510c when the mobile station 510a updates the information on the position where communication interruption may occur will be described in detail. In the description of this operation sequence, both FIGS. 15 and 16 are referred to.

  For example, the vehicle control device outputs vehicle data indicating the state of the unmanned vehicle V to the mobile station 510 at predetermined time intervals.

  When the data input / output unit 512 of the mobile station 510 receives the input of the vehicle data output from the vehicle control device, the data input / output unit 512 transmits the vehicle data to the data transmission / reception unit 511.

  When the data transmission / reception unit 511 of the mobile station 510 receives the vehicle data transmitted from the data input / output unit 512, the data transmission / reception unit 511 transmits the vehicle data to another mobile station 510.

  The data transmission / reception unit 511 of the mobile station 510 that has received the vehicle data sends the vehicle data to the data input / output unit 512.

  The data input / output unit 512 of the mobile station 510 that has received the vehicle data from the data transmission / reception unit 511 outputs the vehicle data to the vehicle control device.

  When receiving the input of the vehicle data output from the mobile station 510, the vehicle control device refers to the state of the other unmanned vehicle V indicated by the vehicle data and cooperates with the other unmanned vehicle V according to a predetermined rule. The unmanned vehicle V is controlled to operate.

  On the other hand, when the information stored in the location information storage unit 119a of the mobile station 510a is updated or new information is stored and updated (S501), the location data transmission / reception unit 523a of the mobile station 510a Is transmitted to other mobile stations 510b and 510c (S502).

  When the position data transmission / reception unit 523b of the mobile station 510b receives the data transmitted from the mobile station 510a, the information indicated by the data is stored in the position information storage unit 119b and updated (S503).

  Similarly, when the position data transmission / reception unit 523c of the mobile station 510c receives the data transmitted from the mobile station 510a, the information indicated by the data is stored and updated in the position information storage unit 119c (S504).

  As described above, when the mobile station 510 receives the data transmitted from the other mobile stations 510 and indicating the information on the position where communication interruption may occur, the mobile station 510 stores the information on the position indicated by the data.

  In this way, depending on the wireless communication system 500, when an obstacle such as a building is newly constructed, or when a building or the like collapses due to a disaster or the like and an obstacle in a rubble mountain is created, etc. By sharing the information between the mobile stations 510, it is possible to prevent communication interruption due to the obstacle in communication between any mobile stations 510.

  FIG. 18 shows an example of a usage environment of a wireless communication system 600 according to the sixth embodiment. The wireless communication system 600 is a system that prevents communication interruption between a mobile station and a base station.

  The wireless communication system 600 includes a mobile station 610, a plurality of base stations 130, and a server 670.

  The mobile station 610 is a moving radio station. For example, the mobile station 610 is provided in the unmanned vehicle V. The mobile station 610 is electrically connected to, for example, a GPS receiver, a vehicle speed sensor, a gyro, and a vehicle control device.

  Base station 130 is a radio station for communicating with mobile station 610. Base station 130 is wirelessly connected to mobile station 610. When the base station 130 receives the operation data transmitted from the operation terminal C, the base station 130 transmits the operation data to the mobile station 610. Further, when the base station 130 receives the vehicle data transmitted from the mobile station 610, the base station 130 transmits the vehicle data to the operation terminal C.

  The server 670 is a computer that provides its own functions and data to the mobile station 610. For example, the server 670 is communicatively connected to the mobile station 610 via the communication line N.

  In this embodiment, a configuration in which the wireless communication system 600 includes one mobile station 610 and a server 670 will be described in order to prevent the description from becoming complicated. However, the wireless communication system 600 may include a plurality of mobile stations 610 and a server 670.

  FIG. 19 shows an example of a block configuration of the mobile station 610. The mobile station 610 includes a data transmission / reception unit 111, a data input / output unit 112, a current position data input reception unit 113, a vehicle speed data input reception unit 114, a gyro data input reception unit 115, a communication interruption determination unit 116, and a wireless communication system change unit 117. , A digital map storage unit 118, a location information storage unit 119, and a location data receiving unit 623. In the following description, the function and operation of each component will be described in detail.

  In addition, among the components of the mobile station 610, components having the same names and the same reference numerals as those of the mobile station 1106 have the same functions and operations.

  The position data receiving unit 623 receives data transmitted from the server 670 and indicating a change in position where communication interruption may occur.

  FIG. 20 shows an example of a block configuration of the server 670. The server 670 includes an observation data reception unit 671, a satellite image generation unit 672, an obstacle change detection unit 673, a position change detection unit 674, a position data transmission unit 675, a satellite image storage unit 676, and a digital map storage unit 677. In the following description, the function and operation of each component will be described in detail.

  The observation data receiving unit 671 receives data indicating observation data transmitted from an artificial satellite. Here, the observation data is data indicating observation results obtained by observing the earth using visible light, infrared rays, and radio waves.

  The satellite image generation unit 672 converts the observation data into an image and generates a satellite image. Here, the satellite image may be an example of “an image obtained by observing the ground from above” in the present invention.

  The obstacle change detection unit 673 detects an obstacle change based on two satellite images obtained by observing the same position on the ground from the sky at different timings.

  When the obstacle change detection unit 673 detects a change in the obstacle, the position change detection unit 674 causes a communication interruption due to the change in the obstacle based on the positional relationship between the obstacle and the base station 130. Detect the change in position you get.

  The position data transmission unit 675 transmits data indicating a change in position where communication interruption may occur to the mobile station 610.

  The satellite image storage unit 676 stores satellite images.

  The digital map storage unit 677 stores a digital map.

  FIG. 21 shows an example of an operation sequence of the artificial satellite, the server 670, and the mobile station 610. In this operation sequence, the operations of the server 670 and the mobile station 610 when a change occurs in an obstacle will be described in detail. In the description of this operation sequence, both FIGS. 18 to 20 are referred to.

  Artificial satellites observe the earth using visible light, infrared rays, and radio waves. Then, the artificial satellite transmits observation data indicating the observation result to the server 670 at predetermined time intervals, for example (S601).

  When the observation data reception unit 671 of the server 670 receives the observation data transmitted from the artificial satellite, the observation data reception unit 671 sends the observation data to the satellite image generation unit 672.

  When the satellite image generation unit 672 of the server 670 receives the data transmitted from the observation data reception unit 671, the satellite image generation unit 672 converts the observation data into an image and generates a satellite image (S602). For example, the satellite image generation unit 672 corrects an error due to the rotation of the earth to convert observation data into an image, and generates a satellite image. Then, the satellite image generation unit 672 stores the generated satellite image in the satellite image storage unit 676.

  In this way, satellite images are sequentially stored in the satellite image storage unit 676 of the server 670.

  When a new satellite image is stored in the satellite image storage unit 676, the obstacle change detection unit 673 of the server 670 includes the new satellite image and the old satellite image stored in the satellite image storage unit 676 before that. Based on the above, a change in the obstacle is detected (S603). For example, the obstacle change detection unit 673 detects an obstacle change that occurs between an old satellite image and a new satellite image by template matching. Then, when the obstacle change detection unit 673 detects a change in the obstacle, the obstacle change detection unit 673 refers to the digital map stored in the digital map storage unit 677 and identifies the geographical coordinates of the obstacle. Then, the obstacle change detection unit 673 sends data indicating the change information of the obstacle and the geographical coordinates of the obstacle to the position change detection unit 674.

  When the position change detection unit 674 of the server 670 receives the data sent from the obstacle change detection unit 673, the position change detection unit 674 is based on the positional relationship between the geographic coordinates of the obstacle indicated by the data and the geographic coordinates of the base station 130. Then, a change in position at which communication interruption with the base station 130 may occur due to a change in the obstacle indicated by the data received from the obstacle change detection unit 673 is detected (S604). For example, when a new obstacle is created, the position change detection unit 674 refers to the digital map stored in the digital map storage unit 677 and newly interrupts communication with the base station 130 by the obstacle. Detect possible locations. Also, for example, when the obstacle disappears, the position change detection unit 674 refers to the digital map stored in the digital map storage unit 677, and communication with the base station 130 is not interrupted by the obstacle. Detect position. Then, the position change detection unit 674 sends position data indicating the change in the position where communication interruption with the detected base station 130 may occur to the position data transmission unit 675.

  When the position data transmission unit 675 of the server 670 receives the position data transmitted from the position change detection unit 674, the position data transmission unit 675 transmits the position data to the mobile station 610 (S605).

  When receiving the position data transmitted from the server 670, the position data receiving unit 623 of the mobile station 610 updates the information in the position information storage unit 119 based on the information indicated by the position data (S606). For example, when the information indicated by the position data is information on a position where communication interruption with the base station 130 may newly occur, the position data receiving unit 623 newly stores the information in the position information storage unit 119. . For example, when the information indicated by the position data is information on a position where communication with the base station 130 is not interrupted, the corresponding information is deleted from the information stored in the position information storage unit 119.

  As described above, the wireless communication system 600 further includes the server 670 connected to the mobile station 610 via the communication line N. Then, the server 670 detects a change in an obstacle based on two satellite images obtained by observing the same position on the ground from the sky at different timings. Then, when detecting a change in an obstacle, the server 670 detects a change in position at which communication interruption may occur due to the change in the obstacle based on the positional relationship between the obstacle and the base station 130. Then, the mobile station 610 stores information on the changed position detected by the server 670.

  Thus, depending on the wireless communication system 600, when an obstacle such as a building is newly constructed, or when a building or the like collapses due to a disaster or the like, an obstacle of a rubble mountain is created, etc. It is possible to prevent communication interruptions caused by things.

  FIG. 22 shows an example of the hardware configuration of the computer 800 constituting the mobile stations 110, 210, 310, 410, 510, 610 and the server 670 according to the present embodiment. A computer 800 according to the present embodiment includes a CPU peripheral unit having a CPU (Central Processing Unit) 802, a RAM (Random Access Memory) 803, a graphic controller 804, and a display 805, and an input / output unit connected to each other by a host controller 801. An input / output unit having a communication interface 807, a hard disk drive 808, and a CD-ROM (Compact Disk Read Only Memory) drive 809 connected to each other by a controller 806, and a ROM (Read Only Memory) connected to the input / output controller 806 810, a flexible disk drive 811 and a legacy input / output unit having an input / output chip 812. Obtain.

  The host controller 801 connects the RAM 803, the CPU 802 that accesses the RAM 803 at a high transfer rate, and the graphic controller 804. The CPU 802 operates based on programs stored in the ROM 810 and the RAM 803 and controls each unit. The graphic controller 804 acquires image data generated on a frame buffer provided in the RAM 803 by the CPU 802 and the like and displays the image data on the display 805. Instead of this, the graphic controller 804 may include a frame buffer for storing image data generated by the CPU 802 or the like.

  The input / output controller 806 connects the host controller 801 to the communication interface 807, the hard disk drive 808, and the CD-ROM drive 809, which are relatively high-speed input / output devices. The hard disk drive 808 stores programs and data used by the CPU 802 in the computer 800. The CD-ROM drive 809 reads a program or data from the CD-ROM 892 and provides it to the hard disk drive 808 via the RAM 803.

  In addition, the input / output controller 806 is connected to the ROM 810, the flexible disk drive 811, and the relatively low-speed input / output device of the input / output chip 812. The ROM 810 stores a boot program that is executed when the computer 800 is started and / or a program that depends on the hardware of the computer 800. The flexible disk drive 811 reads a program or data from the flexible disk 893 and provides it to the hard disk drive 808 via the RAM 803. The input / output chip 812 connects the flexible disk drive 811 to the input / output controller 806 and connects various input / output devices to the input / output controller 806 via, for example, a parallel port, serial port, keyboard port, mouse port, and the like. To do.

  A program provided to the hard disk drive 808 via the RAM 803 is stored in a recording medium such as a flexible disk 893, a CD-ROM 892, or an IC (Integrated Circuit) card and provided by the user. The program is read from the recording medium, installed in the hard disk drive 808 in the computer 800 via the RAM 803, and executed by the CPU 802.

  The first program that is installed in the computer 800 and causes the computer 800 to function as a mobile station determines whether or not communication interruption can occur in the traveling direction D of the unmanned vehicle V in step S104 (S204). When the communication interruption determination unit 116 (216) and the communication interruption determination unit 116 (216) determine that a communication interruption can occur in the traveling direction D of the unmanned vehicle V, in step S105 (S205), the connection should be maintained. It is made to function as the wireless communication system change part 117 (217) which changes a wireless communication system.

  Further, the first program stores the computer 800 in the position information storage unit 119 (219) for storing information on the position where communication interruption may occur, and the position information storage unit 119 (219) in step 104 (204). You may make it function as the communication interruption determination part 116 (216) which determines whether communication interruption may occur in the advancing direction D of the unmanned vehicle V with reference to the stored information.

  Further, the first program calculates the position at which communication interruption may occur due to the obstacle based on the positional relationship between the obstacle detected by the laser displacement sensor and the other station in step S303. The position calculation unit 321 to be operated and the position information calculated by the position calculation unit 321 may function as the position information storage unit 119 stored in step S304.

  Further, the first program continues the computer 800 for a predetermined time or more with a reception level determination unit 422 that determines whether or not the reception level is equal to or lower than a threshold value in step S402 for a predetermined time or longer. When the reception level determination unit 422 determines that the reception level has become equal to or less than the threshold value, it may function as the position information storage unit 119 that stores information on the current position of the unmanned vehicle V in step S403.

  Furthermore, the first program causes the computer 800 to receive a position data transmission / reception unit 523 that receives data indicating information on a position at which communication interruption may occur, transmitted from another station in step S502, and a position data transmission / reception unit 523. The position information indicated by the received data may function as the position information storage unit 119 stored in step S504.

  The second program installed in the computer 800 and causing the computer 800 to function as a server is based on two satellite images obtained by observing the same position on the ground from the sky at different timings in step S603. When the obstacle change detection unit 673 detects an obstacle change and the obstacle change detection unit 673 detects the obstacle change, the obstacle is detected based on the positional relationship between the obstacle and another station. It is made to function as a position change detection unit 674 that detects a change in position that may cause a communication disruption due to the change in.

  Further, the first program may cause the computer 800 to function as the position information storage unit 119 in which the information on the changed position detected by the server position change detection unit 674 is stored in step S606.

  The information processing described in the first program is read by the computer 800, whereby the data transmitting / receiving unit 111 (211), which is a specific means in which the software and the various hardware resources described above cooperate, Input / output unit 112 (212), current position data input reception unit 113 (213), vehicle speed data input reception unit 114 (214), gyro data input reception unit 115 (215), communication interruption determination unit 116 (216), wireless communication Method change unit 117 (217), digital map storage unit 118 (218), position information storage unit 119 (219), obstacle data input reception unit 320, position calculation unit 321, reception level determination unit 422, position data transmission / reception unit 523 , And the position data receiving unit 623. A specific mobile station according to the purpose of use is constructed by realizing calculation or processing of information according to the purpose of use of the computer 800 in this embodiment by these specific means.

  The information processing described in the second program is read into the computer 800, whereby the observation data receiving unit 671, which is a specific means in which the software and the various hardware resources described above cooperate, satellite image generation Functions as a unit 672, an obstacle change detection unit 673, a position change detection unit 674, a position data transmission unit 675, a satellite image storage unit 676, and a digital map storage unit 677. A specific server according to the purpose of use is constructed by realizing calculation or processing of information according to the purpose of use of the computer 800 in this embodiment by these specific means.

  As an example, when communication is performed between the computer 800 and an external device or the like, the CPU 802 executes a communication program loaded on the RAM 803 and executes a communication interface based on the processing content described in the communication program. A communication process is instructed to 807. Under the control of the CPU 802, the communication interface 807 reads transmission data stored in a transmission buffer area or the like provided on a storage device such as the RAM 803, the hard disk drive 808, the flexible disk 893, or the CD-ROM 892, and sends it to the network. The reception data transmitted or received from the network is written into a reception buffer area or the like provided on the storage device. As described above, the communication interface 807 may transfer transmission / reception data to / from the storage device by the direct memory access method. Instead, the CPU 802 reads data from the transfer source storage device or the communication interface 807. The transmission / reception data may be transferred by writing the data to the transfer destination communication interface 807 or the storage device.

  In addition, the CPU 802 transfers all or a necessary part of the files or databases stored in the external storage device such as the hard disk drive 808, CD-ROM 892, and flexible disk 893 to the RAM 803 by direct memory access transfer or the like. The data is read and various processes are performed on the data on the RAM 803. Then, the CPU 802 writes the processed data back to the external storage device by direct memory access transfer or the like.

  In such processing, since the RAM 803 can be regarded as temporarily holding the contents of the external storage device, in the present embodiment, the RAM 803 and the external storage device are collectively referred to as a memory, a storage unit, or a storage device. . Various types of information such as various programs, data, tables, and databases in the present embodiment are stored on such a storage device and are subjected to information processing. In addition, the CPU 802 can hold a part of the RAM 803 in the cache memory and perform reading and writing on the cache memory. Even in such a form, the cache memory bears a part of the function of the RAM 803. Therefore, in the present embodiment, the cache memory is also included in the RAM 803, the memory, and / or the storage device unless otherwise indicated. To do.

  In addition, the CPU 802 performs various operations, such as various operations, information processing, condition determination, information retrieval, replacement, and the like described in the present embodiment for data read from the RAM 803 and specified by a command sequence of the program. Is written back to the RAM 803. For example, when performing the condition determination, the CPU 802 satisfies the conditions such that the various variables shown in the present embodiment are larger, smaller, above, below, or equal to other variables or constants. If the condition is satisfied or not satisfied, the program branches to a different instruction sequence or calls a subroutine.

  In addition, the CPU 802 can search for information stored in a file in a storage device, a database, or the like. For example, when a plurality of entries in which the attribute value of the second attribute is associated with the attribute value of the first attribute are stored in the storage device, the CPU 802 stores the plurality of entries stored in the storage device. The entry that matches the condition in which the attribute value of the first attribute is specified is retrieved, and the attribute value of the second attribute that is stored in the entry is read, thereby associating with the first attribute that satisfies the predetermined condition The attribute value of the specified second attribute can be obtained.

  The program or module described above may be stored in an external storage medium. As a storage medium, in addition to a flexible disk 893 and a CD-ROM 892, an optical recording medium such as a DVD (Digital Versatile Disk) or a CD (Compact Disk), a magneto-optical recording medium such as an MO (Magneto-Optical disk), or a tape A medium, a semiconductor memory such as an IC card, or the like can be used. Further, a storage medium such as a hard disk or RAM provided in a server system connected to a dedicated communication network or the Internet may be used as a recording medium, and the program may be provided to the computer 800 via the network.

  As mentioned above, although this invention was demonstrated using embodiment, the technical scope of this invention is not limited to the range as described in the said embodiment. It will be apparent to those skilled in the art that various changes or improvements can be added to the above-described embodiment. It is apparent from the scope of the claims that the embodiments added with such changes or improvements can also be included in the technical scope of the present invention.

  The execution order of each process such as operations, procedures, steps, and stages in the system, method, apparatus, program, and recording medium shown in the claims, the description, and the drawings is particularly “before”. It should be noted that “preceding” or the like is not specified, and that the output of the previous process can be realized in any order unless it is used in the subsequent process. Regarding the operation flow in the claims, the specification, and the drawings, even if it is described using “first”, “next”, etc. for the sake of convenience, it means that it is essential to carry out in this order. It is not a thing.

DESCRIPTION OF SYMBOLS 100 Wireless communication system 110 Mobile station 111 Data transmission / reception part 112 Data input / output part 113 Current position data input reception part 114 Vehicle speed data input reception part 115 Gyro data input reception part 116 Communication interruption determination part 117 Wireless communication system change part 118 Digital map storage Unit 119 position information storage unit 130 base station 200 wireless communication system 210 mobile station 211 data transmission / reception unit 212 data input / output unit 213 current position data input reception unit 214 vehicle speed data input reception unit 215 gyro data input reception unit 216 communication interruption determination unit 217 Wireless communication system change unit 218 Digital map storage unit 219 Location information storage unit 250 Mobile station 300 Wireless communication system 310 Mobile station 320 Obstacle data input reception unit 321 Position calculation unit 400 Wireless communication system 410 Mobile station 422 Reception level Wireless communication system 510 mobile station 511 data transmission / reception unit 512 data input / output unit 523 position data transmission / reception unit 600 wireless communication system 610 mobile station 623 position data reception unit 670 server 671 observation data reception unit 672 satellite image generation unit 673 Object change detection unit 674 Position change detection unit 675 Position data transmission unit 676 Satellite image storage unit 677 Digital map storage unit 800 Computer 801 Host controller 802 CPU
803 RAM
804 Graphic controller 805 Display 806 Input / output controller 807 Communication interface 808 Hard disk drive 809 CD-ROM drive 810 ROM
811 Flexible disk drive 812 I / O chip 891 Network communication device 892 CD-ROM
893 Flexible disk B Obstacle C Operation terminal D Traveling direction E Location where communication disconnection can occur G Geographic coordinates MV Vehicle N Communication line V Unmanned vehicle

Claims (10)

A wireless communication system for preventing communication interruption between a mobile station and another station,
A mobile station provided on the mobile body;
With other stations that perform wireless communication with the mobile station,
The mobile station
A communication interruption determination unit that determines whether communication interruption may occur in the traveling direction of the mobile body;
A wireless communication system changing unit configured to change a wireless communication system to maintain a connection when the communication interruption determination unit determines that communication interruption may occur in the traveling direction of the mobile body. The mobile station
A location information storage unit for storing location information where communication interruption may occur;
The wireless communication system according to claim 1, wherein the communication interruption determination unit determines whether communication interruption may occur in a traveling direction of the mobile body with reference to information stored in the position information storage unit. . A sensor provided on the moving body for detecting an obstacle;
The mobile station
Based on the positional relationship between the obstacle detected by the sensor and the other station, further comprises a position calculation unit for calculating a position where communication interruption may occur due to the obstacle,
The wireless communication system according to claim 2, wherein the position information storage unit stores information on a position calculated by the position calculation unit. The mobile station
A reception level determination unit that determines whether or not the reception level has become equal to or lower than a threshold value continuously for a predetermined time or more;
3. The position information storage unit stores information on a current position of the mobile body when the reception level determination unit determines that the reception level has become equal to or lower than a threshold value continuously for a predetermined time or longer. Or the radio | wireless communications system of 3. The mobile station
A position data receiving unit that receives data indicating information on a position where communication interruption may occur, transmitted from the other station that is another mobile station;
The wireless communication system according to any one of claims 2 to 4, wherein the position information storage unit stores position information indicated by data received by the position data reception unit. A server that is communicatively connected to the mobile station via a communication line;
The server
An obstacle change detection unit that detects a change in an obstacle based on two images obtained by observing the same position on the ground from the sky at different timings;
When the obstacle change detection unit detects an obstacle change, the obstacle change detection unit detects a change in position at which communication interruption due to the obstacle change may occur based on a positional relationship between the obstacle and the other station. A position change detector,
The wireless communication system according to any one of claims 2 to 5, wherein the position information storage unit stores information on a position after change detected by the position change detection unit. A wireless communication method for preventing communication interruption between a mobile station provided in a mobile body and another station that performs wireless communication with the mobile station,
A communication interruption determination stage for determining whether communication interruption can occur in the traveling direction of the mobile body;
A wireless communication method changing step of changing a wireless communication method to maintain a connection when it is determined in the communication interruption determination step that communication interruption may occur in the traveling direction of the mobile body. A mobile station that is provided in a mobile body and performs wireless communication with other stations,
A communication interruption determination unit that determines whether communication interruption may occur in the traveling direction of the mobile body;
A mobile station comprising: a wireless communication method changing unit that changes a wireless communication method in order to maintain a connection when the communication interruption determination unit determines that communication interruption may occur in the traveling direction of the mobile body. As a mobile station that is provided in a mobile body and performs wireless communication with other stations, a program that causes a computer to function,
The computer,
A communication interruption determination unit for determining whether communication interruption may occur in the traveling direction of the mobile body;
A program that functions as a wireless communication system change unit that changes a wireless communication system to maintain a connection when the communication interruption determination unit determines that communication interruption may occur in the traveling direction of the mobile object. As a mobile station that is provided in a mobile body and performs wireless communication with other stations, a recording medium that records a program that causes a computer to function,
The computer,
A communication interruption determination unit for determining whether communication interruption may occur in the traveling direction of the mobile body;
A recording medium recording a program that functions as a wireless communication system change unit that changes a wireless communication system to maintain a connection when the communication interruption determination unit determines that communication interruption may occur in the traveling direction of the mobile body.

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