Abnormality detection system and abnormality detection method

Abstract

To identify a communication abnormality factor in detail.SOLUTION: In an abnormality detection system, a base station side constitution includes a transmission output measurement part and is provided with base stations for performing radio communication and an abnormality detection part, and an on-vehicle station side constitution includes an RSSI measurement part and is provided with an on-vehicle station for performing radio communication. The transmission output measurement part calculates a transmission output based on a detected transmission value in transmitting a signal from the base station to the on-vehicle station, and the RSSI measurement part measures a reception signal intensity in receiving the signal from the base station. The abnormality detection part compares a predicted value of the reception signal intensity with a measured value of the reception signal intensity at the on-vehicle station and determines the factor of abnormality.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The technology disclosed in this specification relates to anomaly detection technology. [Background technology]

[0002] In a radio train control system, a base station radio along the track communicates with an on-board radio radio installed on the train, and the train automatically controls its speed. Therefore, it is necessary to maintain high-quality radio communication at all times. In the unlikely event that communication quality deteriorates, it is necessary to quickly identify the cause and take action.

[0003] Conventional anomaly detection technologies in radio train control systems include those that identify precise location information when a radio wave anomaly occurs and assist in analyzing the cause of the anomaly by detecting the occurrence of jamming waves or equipment malfunctions (see, for example, Patent Document 1). [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2017-188846 A Summary of the Invention [Problem to be solved by the invention]

[0005] Conventional technology can accurately grasp location information when there is an abnormality in radio waves, making it possible to identify whether the cause of the deterioration in communication quality is interference, equipment failure, etc. However, the user must identify the cause beyond that.

[0006] In other words, it was difficult to identify the detailed cause of the abnormality in communication quality, such as the construction of a new building, the opening of another radio station, environmental changes such as heavy rain, self-interference, or other interference.

[0007] The technology disclosed in this specification has been made in consideration of the problems described above, and is a technology for identifying in detail the cause of a communication anomaly. [Means for solving the problem]

[0008] An anomaly detection system which is a first aspect of the technology disclosed in the present specification comprises a base station side configuration and an on-board station side configuration, the base station side configuration including a transmission output measurement unit and comprising a base station which performs wireless communication and an anomaly detection unit, the on-board station side configuration including an RSSI measurement unit and comprising an on-board station which performs wireless communication, the transmission output measurement unit calculates a transmission output based on a transmission detection value when a signal is transmitted from the base station to the on-board station, the RSSI measurement unit measures a received signal strength when a signal is received from the base station, and the anomaly detection unit compares a predicted value of the received signal strength with an actual measured value of the received signal strength at the on-board station to determine the cause of the anomaly. Effect of the Invention

[0009] According to at least the first aspect of the technology disclosed in the present specification, by predicting the received signal strength, the cause of the abnormality in the received signal strength can be clarified in more detail, and therefore the abnormality in the communication can be dealt with promptly.

[0010] Furthermore, objects, features, aspects and advantages associated with the technology disclosed herein will become more apparent from the detailed description set forth below and the accompanying drawings. [Brief description of the drawings]

[0011] [Figure 1] FIG. 1 illustrates an example of a configuration of an anomaly detection system according to an embodiment. [Diagram 2] FIG. 2 is a diagram illustrating an example of a base station side configuration according to an embodiment. [Diagram 3] FIG. 2 is a diagram showing an example of a configuration of an on-board station according to an embodiment. [Figure 4] FIG. 11 is a diagram showing an example of the flow of measurement data in a base station side configuration. [Diagram 5] FIG. 11 is a diagram showing an example of the flow of measurement data in a configuration on the on-board station side. [Figure 6] 11 is a flowchart illustrating an example of an abnormality detection operation according to the embodiment. [Figure 7] 11 is a diagram illustrating an example of a configuration of an abnormality detection unit and a configuration of a central device side. [Figure 8] FIG. 2 is a diagram illustrating an example of a base station side configuration according to an embodiment. [Figure 9] FIG. 2 is a diagram showing an example of a configuration of an on-board station according to an embodiment. [Figure 10] FIG. 11 is a diagram showing an example of the flow of measurement data in a base station side configuration. [Figure 11] FIG. 11 is a diagram showing an example of the flow of measurement data in a configuration on the on-board station side. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0012] Hereinafter, the embodiments will be described with reference to the accompanying drawings. In the following embodiments, detailed features are shown for the purpose of explaining the technology, but they are merely examples and are not necessarily essential features for enabling the embodiments to be implemented.

[0013] The drawings are schematic, and for the sake of convenience, configurations may be omitted or simplified as appropriate. The size and positional relationship of the configurations shown in different drawings are not necessarily described accurately, and may be changed as appropriate. Hatching may be used in drawings such as plan views that are not cross-sectional views to facilitate understanding of the contents of the embodiments.

[0014] In the following description, the same components are denoted by the same reference numerals, and their names and functions are also the same. Therefore, detailed descriptions thereof may be omitted to avoid duplication.

[0015] Furthermore, in the description in this specification, when a certain component is described as "comprising," "including," or "having," unless otherwise specified, this is not an exclusive expression that excludes the presence of other components.

[0016] Furthermore, even if ordinal numbers such as "first" or "second" are used in the description of this specification, these terms are used for convenience to facilitate understanding of the contents of the embodiments, and the contents of the embodiments are not limited to the orders that may result from these ordinal numbers.

[0017] <First embodiment> The anomaly detection system and an anomaly detection method according to this embodiment will be described below.

[0018] <About the configuration of the anomaly detection system> Fig. 1 is a diagram showing an example of the configuration of an anomaly detection system 1 according to this embodiment. As shown in Fig. 1, the anomaly detection system 1 includes base stations 100, 200, 300, etc. installed along the tracks, a central device 400 connected to each of the base stations, and on-board stations 500, 600, etc. installed on trains. Here, the configuration including the base stations is referred to as the base station side configuration, and the configuration including the on-board stations is referred to as the on-board station side configuration.

[0019] Wireless communication is started by transmitting a communication start signal and time information from the central device 400 to each base station, and then from each base station to the on-board station. After that, the base station and the on-board station measure the time, so that they can know the current time information.

[0020] On-board stations 500 and 600 recognize the location information, and transmit their own location information to base station 100, base station 200 or base station 300 with which they are communicating. The base station that receives the location information transmits the location information of the on-board station to central unit 400 along with on-board station information such as the number of the on-board station.

[0021] Using the received on-board station location information, the central device 400 transmits control instructions for the train in which the on-board station is installed to the on-board station 500 or the on-board station 600 with which it is communicating, via the base station 100, the base station 200, and the base station 300. This operation is repeated.

[0022] Fig. 2 is a diagram showing an example of a base station side configuration according to the present embodiment. Note that, although Fig. 2 specifically shows only the base station side configuration including base station 100, base station 200 and base station 300 also have similar base station side configurations.

[0023] 2, the base station side configuration 2 includes a base station 100, a rainfall measurement unit 120 connected to the base station 100 for measuring rainfall, a radio wave detection device 130 for monitoring radio waves around a frequency used for communication with an on-board station, and an abnormality detection unit 140 for detecting an abnormality based on information acquired from the base station and the on-board station. The abnormality detection unit 140 is connected to the base station 100, the rainfall measurement unit 120, and the radio wave detection device 130.

[0024] The base station 100 includes a data transmitter / receiver 112 for transmitting and receiving data to and from the on-board station, and a transmission output measuring unit 114 for measuring transmission output. The radio wave detection device 130 includes a radio wave receiving unit 132 for receiving radio waves, and an other interference detection unit 134 for detecting other interference.

[0025] In addition, multiple base stations 100, base station 200, base station 300, etc. are connected under the central device 400, and each base station, like base station 100, is connected to a rainfall measurement unit 120, a radio wave detection device 130, and an anomaly detection unit 140.

[0026] Like the base station, the rainfall measurement unit 120, the radio wave detection device 130 and the anomaly detection unit 140 receive a communication start signal and time information from the central device 400, and can determine the current time information by measuring the time (hours).

[0027] Fig. 3 is a diagram showing an example of an on-board station configuration according to the present embodiment. Although Fig. 3 specifically shows only the on-board station configuration including the on-board station 500, the on-board station 600 has a similar on-board station configuration.

[0028] As shown in an example in Figure 3, the on-board station side configuration 3 includes an on-board station 500, a radio wave detection device 520 for monitoring radio waves around the frequency used for communication with the base station, a location information detection unit 530 for detecting location information, and a vehicle control device 540 for controlling the vehicle.

[0029] The on-board station 500 includes a data transmitter / receiver 512 for communicating with a base station, and a received signal strength indicator (RSSI) measurement unit 514. The radio wave detection device 520 includes a radio wave receiver 522 for receiving radio waves, and an other interference detector 524 for detecting other interference.

[0030] The vehicle control device 540 includes a vehicle control unit 542 for controlling the vehicle, and a speed information detection unit 544 for detecting speed information.

[0031] When the on-board station receives a signal to start communication and time information from the base station (or the central device 400), the on-board station also notifies the radio wave detection device 520, the position information detection unit 530, and the vehicle control device 540. Therefore, the radio wave detection device 520, the position information detection unit 530, and the vehicle control device 540 can also grasp the current time information by measuring the time (hours).

[0032] Functional units such as the abnormality detection unit 140 and the vehicle control unit 542 in Figures 2 and 3 control the controlled object by executing a program stored in an internal or external recording medium (such as a volatile or non-volatile memory such as a HDD, RAM, ROM or flash memory), and are composed of, for example, a central processing unit (CPU), a microprocessor or a microcomputer.

[0033] <About the operation of the anomaly detection system> Next, the flow of measurement data in the base station side configuration according to this embodiment will be described with reference to Fig. 4. Here, Fig. 4 is a diagram showing an example of the flow of measurement data in the base station side configuration.

[0034] The transmission output measuring unit 114 periodically calculates the transmission output from the transmission detection value when a signal is transmitted from the base station 100 to the on-board station 500. Then, the transmission output measuring unit 110 transmits the transmission output based on the transmission detection value together with time information to a server 141 provided in the abnormality detecting unit 140.

[0035] The rainfall measuring unit 120 periodically measures the amount of rainfall and transmits the information on the amount of rainfall together with time information to the server 141.

[0036] The other interference detection unit 134 is set to a frequency around the frequency used for communication with the on-board station, and transmits the measured RSSI periodically to the server 141 together with time information.

[0037] The server 141 stores data on transmission output, rainfall, and other interference (RSSI of surrounding frequencies) for a certain period of time, as well as corresponding time information.

[0038] Next, the flow of measurement data in the on-board station configuration according to this embodiment will be described with reference to Fig. 5. Here, Fig. 5 is a diagram showing an example of the flow of measurement data in the on-board station configuration.

[0039] The RSSI measurement unit 514 installed in the on-board station 500 periodically measures the received signal strength (RSSI) at the on-board station 500 when receiving a signal from a base station. The other interference detection unit 524 sets a frequency around the frequency used for communication with the base station, and periodically measures the RSSI.

[0040] The position information detection unit 530 periodically acquires train position information. The position information is acquired using a GPS or the like. The speed information detection unit 544 periodically acquires train speed information.

[0041] The data acquired by the RSSI measurement unit 514, other interference detection unit 524, location information detection unit 530 and speed information detection unit 544, as well as the time information at that time, are transmitted to the base station 100 via the data transmission / reception unit 512 of the on-board station 500.

[0042] Furthermore, the base station 100 transmits the received data to a server 141 in the abnormality detection unit 140. Similar to the data from the base station, the server 141 stores the data for a certain period transmitted from the on-board station and the corresponding time information data.

[0043] Next, the distance between the base station and the on-board station will be described. As described above, the location information detected by the location information detection unit 530 is transmitted to the server 141 via the base station. Since the base station is a fixed station, it is assumed that the server 141 is aware of information such as the location information (GPS) of the base station connected to the server 141. Therefore, the server 141 can calculate the distance between the base station and the on-board station using the location information of the base station and the location information of the on-board station. At this time, the server 141 stores the location information of the on-board station and the distance between the base station and the on-board station in association with each other.

[0044] In this embodiment, abnormality detection is performed using a prediction of the RSSI received by the on-board station. Here, information required for predicting the RSSI will be described.

[0045] Factors that cause degradation of RSSI include attenuation (for example, attenuation due to distance, attenuation due to diffraction caused by obstacles, or attenuation due to rain, etc.), self-interference (for example, interference with one's own radio waves caused by obstacles such as the construction of a new building, etc.), and other interference (for example, interference with radio waves caused by other communications due to jamming radio waves or the opening of another radio station nearby, etc.) In addition, the transmission power measured by the base station also affects the RSSI (for example, if the transmission power is small, the RSSI on the receiving side will also be small accordingly).

[0046] The correspondence between these degradation factors and the data obtained in Figures 4 and 5 (i.e., transmission output, rainfall, on-board station location information, other interference detected by the on-board station configuration, and distance between the base station and the on-board station) is as follows:

[0047] In other words, distance attenuation corresponds to the distance between the base station and the on-board station, diffraction attenuation due to obstacles corresponds to location information, rain attenuation corresponds to the amount of rain, radio wave interference from one's own radio waves due to obstacles such as the construction of a new building corresponds to location information, radio wave interference from other communications such as jamming radio waves or another radio station opening nearby corresponds to other interference detected by the on-board station, and the transmission power measured at the base station corresponds to the transmission power.

[0048] In this embodiment, the other interference detection unit 134 in the base station configuration does not contribute to the detection of an abnormality in the RSSI.

[0049] The server 141 of the anomaly detection unit 140 acquires the received signal strength indicator (RSSI) at the on-board station as reference data for each signal, such as transmission output, rainfall, on-board station location information, other interference detected at the on-board station, and distance between the base station and the on-board station, before operating the anomaly detection system, and obtains a multiple regression equation for RSSI that represents a predicted value of the received signal strength indicator (RSSI) at the on-board station in advance. The coefficients in the multiple regression equation are arbitrary, as they differ for each system.

[0050] In addition, since location information is a qualitative variable, the RSSI is acquired under constant weather and transmission power, and the correlation between the location and the RSSI is calculated and converted into a quantitative variable. The correlation coefficient between the predicted value and the actual measured value of the on-board station's received signal strength indicator (RSSI) differs for each system, so it is arbitrary.

[0051] In addition, the on-board station determines in advance the position where it will receive signals from the base station (measure RSSI). As will be described later, in order to compare the predicted RSSI with the actually measured RSSI, the position where the signal is received is set to the same position where the reference data was acquired. To achieve this, the base station uses the time information, position information, and speed information received from the on-board station to control transmission so that the on-board station can receive signals at the determined position.

[0052] Next, an anomaly detection flow according to this embodiment will be described with reference to Fig. 6. Here, Fig. 6 is a flowchart showing an example of an anomaly detection operation according to this embodiment.

[0053] The RSSI threshold value is determined in advance according to the transmission output and the distance between the base station and the on-board station, and the RSSI threshold value is stored in the server 141. In addition, the threshold values ​​at which the respective values ​​become abnormal for the amount of rainfall and other interference are determined in advance, and these threshold values ​​are stored in the server 141.

[0054] In step ST1, the abnormality detection unit 140 judges whether the actual measured value of the RSSI of the on-board station at the position of the moving train exceeds an RSSI threshold value according to the transmission power and the distance between the on-board station corresponding to the position information of the moving train and the base station. If it exceeds the threshold value, it judges it to be normal and outputs "no abnormality" (step ST2). On the other hand, if it is equal to or less than the threshold value (i.e., an abnormality has occurred), it proceeds to step ST3 and checks whether the values ​​of the rainfall and other interference are abnormal.

[0055] Next, in step ST4, it is determined whether the RSSI actually measured at the on-board station matches the predicted RSSI calculated from the multiple regression equation calculated from the reference data and the data input to the server 141 (i.e., transmission output, rainfall, other interference, location information, and the distance between the base station and the on-board station).

[0056] If the two are the same, in step ST9, it is determined whether the input rainfall and other interference exceed their respective thresholds. If the rainfall and other interference exceed their respective thresholds, they are determined to be abnormal and are output to the client PC.

[0057] On the other hand, if the two do not match, the process proceeds to step ST5, where the RSSIs of trains running within the area of ​​the base station 100 are compared, and detailed causes of degradation of the RSSI are output.

[0058] In step ST5, in order to compare RSSI, it is confirmed whether data on the required number of trains (number of trains) running within the base station area after the abnormality occurs is available. Since the frequency of train traffic differs depending on the line section, the number of data to be used is arbitrary.

[0059] If the number of data determined in step ST5 is not available, the process proceeds to step ST13, where a temporary RSSI anomaly is provisionally output to the client PC since the detailed cause is unknown at this stage. Also, in step ST3, based on the result of judging whether the inputted rainfall and other interference exceed their respective thresholds, if the rainfall and other interference exceed their respective thresholds, an anomaly is also detected in the rainfall and other interference and output to the client PC.

[0060] On the other hand, if the determined number of data items has been collected in step ST5, the process proceeds to step ST6, where a determination is made as to whether or not an RSSI abnormality has occurred instantaneously at the same location, using the relationship between the location information of the required number of trains stored in server 141 and the RSSI.

[0061] If an RSSI abnormality occurs instantaneously for all trains at the same position, in step ST10, it is output to the client PC as an occurrence of self-interference due to building construction, etc. Also, in step ST3, based on the result of judging whether the inputted rainfall and other interference exceed their respective thresholds, if the rainfall and other interference exceed their respective thresholds, it is output to the client PC as an abnormality in the rainfall and other interference as well.

[0062] On the other hand, if there is no momentary RSSI abnormality at the same position, in step ST7, it is determined whether or not RSSI abnormalities occur constantly in all trains running within the area of ​​the base station 100.

[0063] If an abnormality occurs in all trains corresponding to a certain base station, the fact that the base station is degraded is output to the client PC in step ST11. Also, in step ST3, as a result of determining whether the input rainfall and other interference exceed their respective thresholds, if the rainfall and other interference exceed their respective thresholds, an abnormality is output to the client PC regarding the rainfall and other interference as well.

[0064] On the other hand, if the abnormality is not a momentary one at the same location and no abnormality is occurring in any train, in step ST8, it is determined whether or not an RSSI abnormality is constantly occurring in only a specific train among the trains running within the area of ​​base station 100.

[0065] If an abnormality occurs constantly only in a specific train, the on-board station degradation is output to the client PC in step ST12. Also, in step ST3, based on the result of judging whether the inputted rainfall and other interference exceed their respective thresholds, if the rainfall and other interference exceed their respective thresholds, an abnormality is also output to the client PC regarding the rainfall and other interference.

[0066] On the other hand, if there is no momentary abnormality at the same position and no constant RSSI abnormality, this is RSSI degradation that does not require special consideration (due to temporary artificial noise or diffraction attenuation due to obstacles such as birds), and so in step ST13, a temporary abnormality is output to the client PC. Also, in step ST3, based on the result of judging whether the inputted rainfall and other interference exceed their respective thresholds, if the rainfall and other interference each exceed their threshold, an abnormality is also output to the client PC for the rainfall and other interference.

[0067] Furthermore, in steps ST9 to ST13, if the amount of rain or other interference is abnormal in step ST3, the information is also output, making it possible to deal with cases where there are multiple factors that cause deterioration of the RSSI.

[0068] Next, the operation of the abnormality detection unit 140 according to this embodiment will be described with reference to Fig. 6 and Fig. 7. Here, Fig. 7 is a diagram showing an example of the configuration of the abnormality detection unit and the central device side configuration.

[0069] 7, anomaly detection unit 140 includes a server 141 and a data storage device 142. Server 141 stores data by time, and when new data is received, it transmits the oldest data first to data storage device 142. Central device side configuration 4 includes a central device 400 and a client PC 410. When a client requires data, client PC 410 can retrieve data (including the determination result of the cause of anomaly) from data storage device 142 via central device 400 and server 141, and display the data.

[0070] In the case of steps ST9 to ST13, when the client PC 410 receives from the server 141 information that an abnormality has occurred, the client PC 410 displays on the display unit information about the abnormality and which abnormality occurred from steps ST9 to ST13, thereby enabling the client to immediately be informed of what RSSI abnormality has occurred.

[0071] In addition, the RSSI can be improved by taking measures such as placing the base station in an appropriate location (installing a new base station) in step ST10, replacing or repairing the base station in step ST11, and replacing or repairing the on-board station in step ST12.

[0072] If a station is to be positioned, the system can be continued by acquiring reference data again, updating the multiple regression coefficients, and changing the qualitative variables to quantitative variables.

[0073] In this embodiment, data is displayed on the client PC 410 only when requested by the client, except when an abnormality occurs. However, the data may be displayed at all times even when no abnormality occurs.

[0074] In this embodiment, the case where the present invention is applied to a radio train control system has been described. However, since the multiple regression analysis is performed using position information, the present invention can also be applied to route buses or ships whose travel routes are fixed.

[0075] In addition, in this embodiment, the server 141 calculates the distance between the base station 100 and the on-board station 500 using pre-stored location information (GPS information) of the base station 100 and the location information of the on-board station 500 transmitted from the on-board station 500. However, it is also possible to calculate in advance the distance between the location on the railroad (such as kilometers) within the communication area of ​​the base station 100 and the location of the base station 100, and store the location on the railroad in association with the distance from the base station, and based on the location information on the railroad (such as kilometers) transmitted from the on-board station 500, use the distance between the stored location on the railroad and the corresponding base station as the distance between the base station 100 and the on-board station 500.

[0076] As described above, by predicting the RSSI, the cause of the RSSI abnormality becomes clear in more detail, and the RSSI abnormality can be dealt with promptly.

[0077] <Second embodiment> An anomaly detection system and an anomaly detection method according to the present embodiment will be described. In the following description, components similar to those described in the above embodiment will be denoted by the same reference numerals, and detailed description thereof will be omitted as appropriate.

[0078] <About the configuration of the anomaly detection system> In the first embodiment, abnormality detection is performed using the RSSI of the on-board station, but abnormality detection may also be performed using the RSSI of the base station. In this embodiment, abnormality detection is performed using a prediction of the received signal strength indicator (RSSI) measured at the base station.

[0079] Fig. 8 is a diagram showing an example of a base station side configuration according to the present embodiment. Note that, although Fig. 8 specifically shows only the base station side configuration including the base station 100A, the same base station side configuration is also configured for the base station 200A and the base station 300A.

[0080] 8, the base station side configuration 2A includes a base station 100A, a rainfall measuring unit 120 connected to the base station 100A, a radio wave detection device 130, and an abnormality detection unit 140. The abnormality detection unit 140 is connected to the base station 100A, the rainfall measuring unit 120, and the radio wave detection device 130.

[0081] The base station 100A includes a data transmitter / receiver 112 and an RSSI measurement unit 116 that periodically measures the received signal strength indicator (RSSI). The radio wave detection device 130 includes a radio wave receiver 132 and an other interference detection unit 134.

[0082] In addition, multiple base stations, namely, base station 100A, base station 200A, base station 300A, etc., are connected under the central device 400, and each base station, like base station 100A, is connected to a rainfall measurement unit 120, a radio wave detection device 130, and an anomaly detection unit 140.

[0083] Like the base station, the rainfall measurement unit 120, the radio wave detection device 130 and the anomaly detection unit 140 receive a communication start signal and time information from the central device 400, and can determine the current time information by measuring the time (hours).

[0084] Fig. 9 is a diagram showing an example of an on-board station configuration according to the present embodiment. Note that, although Fig. 9 specifically shows only the on-board station configuration including the on-board station 500A, the same on-board station configuration is configured for the other on-board stations.

[0085] As shown in the example in FIG. 9, the on-board station side configuration 3A includes an on-board station 500A, a radio wave detection device 520, a position information detection unit 530, and a vehicle control device 540.

[0086] The on-board station 500A includes a data transmitter / receiver 512 and a transmission output measuring unit 516 that measures transmission output. The radio wave detection device 520 includes a radio wave receiving unit 522 and an other interference detection unit 524. The vehicle control device 540 includes a vehicle control unit 542 and a speed information detection unit 544.

[0087] When the on-board station receives a signal to start communication and time information from the base station (or the central device 400), the on-board station also notifies the radio wave detection device 520, the position information detection unit 530, and the vehicle control device 540. Therefore, the radio wave detection device 520, the position information detection unit 530, and the vehicle control device 540 can also grasp the current time information by measuring the time (hours).

[0088] Functional units such as the abnormality detection unit 140 and the vehicle control unit 542 in Figures 8 and 9 control the controlled object by executing a program stored in an internal or external recording medium (such as a volatile or non-volatile memory such as a HDD, RAM, ROM or flash memory), and are composed of, for example, a CPU, a microprocessor or a microcomputer.

[0089] <About the operation of the anomaly detection system> Next, the flow of measurement data in the base station side configuration according to this embodiment will be described with reference to Fig. 10. Here, Fig. 10 is a diagram showing an example of the flow of measurement data in the base station side configuration.

[0090] The rainfall measuring unit 120 periodically measures the amount of rainfall and transmits the information on the amount of rainfall together with time information to the server 141.

[0091] The other interference detection unit 134 is set to a frequency around the frequency used for communication with the on-board station, and transmits the measured RSSI periodically to the server 141 together with time information.

[0092] The transmission output measuring unit 114 periodically calculates the transmission output from the transmission detection value when a signal is transmitted from the base station 100 to the on-board station 500. Then, the transmission output measuring unit 110 transmits the transmission output based on the transmission detection value together with time information to a server 141 provided in the abnormality detecting unit 140.

[0093] The RSSI measurement unit 116 mounted on the base station 100A measures the RSSI when receiving a signal from the on-board station 500A. Then, the RSSI measurement unit 116 transmits the RSSI to the server 141 together with time information.

[0094] The server 141 stores data on the amount of rainfall for a certain period of time, other interference, and the RSSI and corresponding time information when a signal is received from the on-board station 500A.

[0095] Next, the flow of measurement data in the on-board station configuration according to this embodiment will be described with reference to Fig. 11. Here, Fig. 11 is a diagram showing an example of the flow of measurement data in the on-board station configuration.

[0096] The other interference detection unit 524 sets a frequency around the frequency used for communication with the base station and periodically measures the RSSI. The location information detection unit 530 periodically acquires train location information. GPS or the like is used to acquire the location information.

[0097] The speed information detection unit 544 periodically acquires train speed information. The transmission output measurement unit 516 periodically calculates the transmission output from the transmission detection value when a signal is transmitted from the on-board station 500A to the base station 100A. The transmission output measurement unit 516 then transmits the transmission output based on the transmission detection value together with time information to the server 141 provided in the abnormality detection unit 140.

[0098] The data acquired by the other interference detection unit 524, the location information detection unit 530, the speed information detection unit 544 and the transmission output measurement unit 516, as well as the time information at that time, are transmitted to the base station 100A via the data transmission / reception unit 512 of the on-board station 500A.

[0099] Furthermore, the base station 100A transmits the received data to the server 141. As with the data from the base stations, the server 141 stores the data for a certain period transmitted from the on-board station and the corresponding time information data.

[0100] In addition, the on-board station determines in advance the position where it will receive signals from the base station (measure RSSI). To this end, the base station uses the time, position, and speed information received from the on-board station to control transmission so that the on-board station can receive signals at the determined position.

[0101] The calculation of the distance between the base station and the on-board station is the same as in the first embodiment, and therefore a detailed description thereof will be omitted.

[0102] In this embodiment, abnormality detection is performed using a prediction of the RSSI received by the base station. Here, information required for predicting the RSSI will be described.

[0103] Factors that cause degradation of RSSI include attenuation (for example, attenuation due to distance, attenuation due to diffraction caused by obstacles, or attenuation due to rain, etc.), self-interference (for example, interference with one's own radio waves caused by obstacles such as the construction of a new building, etc.), and other interference (for example, interference with radio waves caused by other communications due to jamming radio waves or the opening of another radio station nearby, etc.) In addition, the transmission power measured by the base station also affects the RSSI (for example, if the transmission power is small, the RSSI on the receiving side will also be small accordingly).

[0104] The correspondence between these degradation factors and the data obtained in Figures 10 and 11 (i.e., rainfall amount, other interference detected by the base station, location information of the on-board station, distance between the base station and the on-board station, and transmission output) is as follows.

[0105] In other words, distance attenuation corresponds to the distance between the base station and the on-board station, diffraction attenuation due to obstacles corresponds to location information, rain attenuation corresponds to the amount of rain, radio wave interference from one's own radio waves due to obstacles such as the construction of a new building corresponds to location information, radio wave interference from other communications such as jamming radio waves or another radio station opening nearby corresponds to other interference detected by the base station, and the transmission power measured at the on-board station corresponds to transmission power.

[0106] In this embodiment, the other interference detection unit 524 in the on-board station configuration does not contribute to the detection of an abnormality in the RSSI.

[0107] The server 141 acquires the amount of rainfall, other interference detected by the base station, the location information of the on-board station, the distance between the base station and the on-board station, and the transmission output as reference data before operating the anomaly detection system, and obtains a multiple regression equation for RSSI that represents the predicted value of the received signal strength indicator (RSSI) of the base station in advance. The coefficients in the multiple regression equation are arbitrary because they differ for each system.

[0108] In addition, since location information is a qualitative variable, we obtain RSSI under constant weather and transmission power, and convert it into a quantitative variable by taking the correlation between location and RSSI. The correlation coefficient between the predicted and measured received signal strength (RSSI) values ​​of the base station differs for each system, so it is arbitrary.

[0109] The anomaly detection operation and the operation of the anomaly detection unit 140 in this embodiment are the same as those in the first embodiment, and therefore detailed description will be omitted. However, in step ST4, it is determined whether the RSSI actually measured at the base station matches the predicted RSSI calculated from the multiple regression equation calculated from the reference data and the data input to the server 141 (i.e., the transmission output, the amount of rain, other interference, location information, and the distance between the base station and the on-board station).

[0110] As described above, by predicting the RSSI, the cause of the RSSI abnormality becomes clear in more detail, and the RSSI abnormality can be dealt with promptly.

[0111] <Effects of the above-described embodiments> Next, examples of effects produced by the above-described embodiments are shown. In the following description, the effects are described based on the specific configurations shown as examples in the above-described embodiments, but may be replaced with other specific configurations shown as examples in this specification as long as the same effects are produced. In other words, for convenience, only one of the corresponding specific configurations may be described as a representative below, but the representatively described specific configuration may be replaced with another corresponding specific configuration.

[0112] Furthermore, the replacement may be made across a number of embodiments, that is, configurations shown as examples in different embodiments may be combined to produce the same effect.

[0113] According to the embodiment described above, the anomaly detection system includes a base station side configuration 2 and an on-board station side configuration 3. The base station side configuration 2 includes a base station 100 that performs wireless communication, and an anomaly detection unit 140. The base station 100 includes a transmission output measurement unit 114. The on-board station side configuration 3 includes an on-board station 500 that performs wireless communication. The on-board station 500 includes an RSSI measurement unit 514. The transmission output measurement unit 114 calculates a transmission output based on a transmission detection value when a signal is transmitted from the base station 100 to the on-board station 500. The RSSI measurement unit 514 measures a received signal strength when a signal is received from the base station 100. Then, the anomaly detection unit 140 compares a predicted value of the received signal strength with an actual measured value of the received signal strength at the on-board station 500 to determine the cause of the anomaly.

[0114] According to this configuration, by predicting the received signal strength, the cause of the abnormality in the received signal strength at the on-board station can be clarified in more detail. Therefore, when the communication quality deteriorates, the abnormality can be dealt with promptly, which contributes to safe and stable transportation.

[0115] Furthermore, the same effect can be achieved even if other configurations, examples of which are shown in this specification, are appropriately added to the above configuration, i.e., even if other configurations in this specification that were not mentioned as the above configuration are appropriately added.

[0116] According to the embodiment described above, the abnormality detection system includes a base station side configuration 2A and an on-board station side configuration 3A. The base station side configuration 2A includes a base station 100A that performs wireless communication, and an abnormality detection unit 140. The base station 100A includes an RSSI measurement unit 116. The on-board station side configuration 3A includes an on-board station 500A that performs wireless communication. The on-board station 500A includes a transmission output measurement unit 516. The RSSI measurement unit 116 measures the received signal strength when a signal is received from the on-board station 500A. The transmission output measurement unit 516 calculates the transmission output based on the transmission detection value when a signal is transmitted from the on-board station 500A to the base station 100A. Then, the abnormality detection unit 140 compares the predicted value of the received signal strength with the actual measured value of the received signal strength at the base station 100A to determine the cause of the abnormality. According to such a configuration, the abnormality cause of the received signal strength at the base station can be clarified in more detail by predicting the received signal strength. Therefore, when the communication quality deteriorates, the abnormality can be dealt with promptly.

[0117] According to the embodiment described above, the anomaly detection unit 140 outputs the cause of the determined anomaly to the outside. With such a configuration, the cause of the anomaly in the received signal strength can be promptly presented to the user.

[0118] Moreover, according to the embodiment described above, the base station side configuration 2 (or the base station side configuration 2A) includes a rainfall measurement unit 120 that measures rainfall. The on-board station side configuration 3 (or the on-board station side configuration 3A) includes an other interference detection unit 524 that measures the received signal strength around the frequency used in communication with the base station 100 (or the base station 100A) as other interference. Then, the abnormality detection unit 140 determines the cause of the abnormality based on the rainfall and other interference when the predicted value of the received signal strength matches the actual measured value of the received signal strength. With such a configuration, even if the received signal strength matches the predicted value, it is possible to clarify the cause of the abnormality in more detail based on the rainfall and other interference.

[0119] Furthermore, according to the embodiment described above, the on-board station 500 (or the on-board station 500A) is installed on a train. Then, when the predicted value of the received signal strength does not match the actual measured value of the received signal strength, the abnormality detection unit 140 determines the cause of the abnormality based on the number of train formations and the number of trains whose predicted value does not match the actual measured value. With this configuration, when the received signal strength does not match the predicted value, it is possible to clarify the cause of the abnormality in more detail based on information about the train that is the subject of the abnormality detection.

[0120] Furthermore, according to the embodiment described above, the anomaly detection unit 140 calculates a predicted value of the received signal strength by multiple regression analysis based on the reference data. Here, the reference data is data including the transmission power that is acquired in advance by the anomaly detection unit 140. With this configuration, the predicted value of the received signal strength is calculated by performing multiple regression analysis based on the reference data (including the transmission power) acquired in advance, and can be used to detect detailed causes of the anomaly.

[0121] According to the embodiment described above, in the anomaly detection method, the received signal strength is measured when a signal is received from the base station 100 or the on-board station 500. Then, the corresponding predicted value of the received signal strength is compared with the actual measured value of the received signal strength to determine the cause of the anomaly.

[0122] According to this configuration, by predicting the received signal strength, the cause of the abnormality in the received signal strength can be clarified in more detail. Therefore, when the communication quality deteriorates, the abnormality can be dealt with promptly, which contributes to the safety and stability of transportation.

[0123] Unless otherwise specified, the order in which the processes are performed may be changed.

[0124] Furthermore, even if other configurations, examples of which are shown in this specification, are appropriately added to the above configuration, i.e., other configurations in this specification that were not mentioned as the above configuration are appropriately added, the same effect can be produced.

[0125] <Modifications of the above-described embodiments> In the embodiments described above, the dimensions, shapes, relative positional relationships, and implementation conditions of each component may be described, but these are merely examples in all aspects and are not limiting.

[0126] Therefore, countless modifications and equivalents not shown as examples are assumed within the scope of the technology disclosed in the present specification, including, for example, modifying, adding, or omitting at least one component, and further, extracting at least one component in at least one embodiment and combining it with a component in another embodiment.

[0127] Furthermore, unless a contradiction arises, when it is stated in the above-described embodiments that "one" component is provided, "one or more" of that component may be provided.

[0128] Furthermore, each component in the embodiments described above is a conceptual unit, and the scope of the technology disclosed in this specification includes cases where one component is made up of multiple structures, where one component corresponds to a part of a structure, and even where multiple components are provided in one structure.

[0129] Furthermore, each of the components in the embodiments described above includes structures having other structures or shapes as long as they perform the same function.

[0130] Furthermore, the descriptions in this specification are incorporated by reference for all purposes related to the present technology, and none of them are admitted to be prior art.

[0131] Various aspects of the present disclosure are summarized below as appendices.

[0132] (Appendix 1) A base station side configuration; An on-board station configuration, The base station side configuration is a base station including a transmission output measurement unit and performing wireless communication; An abnormality detection unit, The on-board station side configuration is The vehicle-mounted station includes an RSSI measurement unit and performs wireless communication. The transmission output measurement unit calculates a transmission output based on a transmission detection value when a signal is transmitted from the base station to the on-board station, The RSSI measurement unit measures a received signal strength when receiving a signal from the base station, the abnormality detection unit compares the predicted value of the received signal strength with an actual measured value of the received signal strength at the on-board station to determine a cause of the abnormality; Anomaly detection systems.

[0133] (Appendix 2) A base station side configuration; An on-board station configuration, The base station side configuration is A base station that includes an RSSI measurement unit and performs wireless communication; An abnormality detection unit, The on-board station side configuration is The vehicle-mounted station includes a transmission output measuring unit and performs wireless communication. The RSSI measurement unit measures a received signal strength when receiving a signal from the on-board station, The transmission output measurement unit calculates a transmission output based on a transmission detection value when a signal is transmitted from the on-board station to the base station, the abnormality detection unit compares the predicted value of the received signal strength with an actual measured value of the received signal strength at the base station to determine a cause of the abnormality; Anomaly detection systems.

[0134] (Appendix 3) 3. The anomaly detection system according to claim 1 or 2, The abnormality detection unit outputs the determined cause of the abnormality to an outside. Anomaly detection systems.

[0135] (Appendix 4) 4. An anomaly detection system according to any one of claims 1 to 3, The base station side configuration is A rainfall measuring unit for measuring rainfall is further provided, The on-board station side configuration is Further, a different interference detection unit is provided which measures the received signal strength around a frequency used in communication with the base station as different interference, the abnormality detection unit determines a cause of the abnormality based on the amount of rain and the other interference when the predicted value of the received signal strength coincides with the actual measured value of the received signal strength; Anomaly detection systems.

[0136] (Appendix 5) 4. An anomaly detection system according to any one of claims 1 to 3, The on-board station is installed in a train, when the predicted value of the received signal strength does not match the actual measured value of the received signal strength, the abnormality detection unit determines a cause of the abnormality based on the number of train configurations and the number of trains for which the predicted value does not match the actual measured value; Anomaly detection systems.

[0137] (Appendix 6) 6. An anomaly detection system according to any one of claims 1 to 5, the abnormality detection unit calculates the predicted value of the received signal strength by multiple regression analysis based on reference data; The reference data is data including the transmission output, the data being acquired in advance by the abnormality detection unit. Anomaly detection systems.

[0138] (Appendix 7) An abnormality detection method performed by an abnormality detection system including a base station side configuration and an on-board station side configuration, The base station side configuration includes a base station that performs wireless communication, The on-board station side configuration includes an on-board station that performs wireless communication, Measure the received signal strength when receiving a signal from the base station or the on-board station; comparing the corresponding predicted value of received signal strength with the actual measured value of received signal strength to determine the cause of the anomaly; Anomaly detection methods. [Explanation of symbols]

[0139] 1 Anomaly detection system, 2 Base station side configuration, 2A Base station side configuration, 3 On-board station side configuration, 3A On-board station side configuration, 4 Central device side configuration, 100 Base station, 100A Base station, 110 Transmission output measurement unit, 112 Data transmission / reception unit, 114 Transmission output measurement unit, 116 RSSI measurement unit, 120 Rainfall measurement unit, 130 Radio wave detection device, 132 Radio wave reception unit, 134 Other interference detection unit, 140 Anomaly detection unit, 141 Server, 142 Data storage device, 200 Base station, 200A Base station, 300 Base station, 300A Base station, 400 Central device, 410 Client PC, 500 On-board station, 500A On-board station, 512 Data transmission / reception unit, 514 RSSI measurement unit, 516 Transmission output measurement unit, 520 Radio wave detection device, 522 Radio wave reception unit, 524 Other interference detection unit, 530 position information detection unit, 540 vehicle control device, 542 vehicle control unit, 544 speed information detection unit, 600 on-board station.

Claims

1. A base station side configuration; An on-board station configuration, The base station side configuration is a base station including a transmission output measurement unit and performing wireless communication; An abnormality detection unit, The on-board station side configuration is An on-board station including an RSSI measurement unit and performing wireless communication, The transmission output measurement unit calculates a transmission output based on a transmission detection value when a signal is transmitted from the base station to the on-board station, The RSSI measurement unit measures a received signal strength when receiving a signal from the base station, the abnormality detection unit compares the predicted value of the received signal strength with an actual measured value of the received signal strength at the on-board station to determine a cause of the abnormality; Anomaly detection systems.

2. A base station side configuration; An on-board station configuration, The base station side configuration is A base station including an RSSI measurement unit and performing wireless communication; An abnormality detection unit, The on-board station side configuration is The vehicle-mounted station includes a transmission output measuring unit and performs wireless communication. The RSSI measurement unit measures a received signal strength when receiving a signal from the on-board station, The transmission output measurement unit calculates a transmission output based on a transmission detection value when a signal is transmitted from the on-board station to the base station, the abnormality detection unit compares the predicted value of the received signal strength with an actual measured value of the received signal strength at the base station to determine a cause of the abnormality; Anomaly detection systems.

3. 3. The anomaly detection system according to claim 1, The abnormality detection unit outputs the determined cause of the abnormality to an outside. Anomaly detection systems.

4. 3. The anomaly detection system according to claim 1, The base station side configuration is A rainfall measuring unit for measuring rainfall is further provided, The on-board station side configuration is Further, a different interference detection unit is provided which measures the received signal strength around a frequency used in communication with the base station as different interference, the abnormality detection unit determines a cause of the abnormality based on the amount of rain and the other interference when the predicted value of the received signal strength coincides with the actual measured value of the received signal strength; Anomaly detection systems.

5. 3. The anomaly detection system according to claim 1, The on-board station is installed in a train, when the predicted value of the received signal strength does not match the actual measured value of the received signal strength, the abnormality detection unit determines a cause of the abnormality based on the number of train configurations and the number of trains for which the predicted value does not match the actual measured value; Anomaly detection systems.

6. 3. The anomaly detection system according to claim 1, the abnormality detection unit calculates the predicted value of the received signal strength by multiple regression analysis based on reference data; The reference data is data including the transmission output, the data being acquired in advance by the abnormality detection unit. Anomaly detection systems.

7. An abnormality detection method performed by an abnormality detection system including a base station side configuration and an on-board station side configuration, The base station side configuration includes a base station that performs wireless communication, The on-board station side configuration includes an on-board station that performs wireless communication, Measure the received signal strength when receiving a signal from the base station or the on-board station; comparing the corresponding predicted value of received signal strength with the actual measured value of received signal strength to determine the cause of the anomaly; Anomaly detection methods.

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