JP7011065B2 - Communication environment measuring device and vehicle communication environment measuring method - Google Patents

Description

The present invention relates to a communication environment measuring device and a method for measuring a communication environment of a vehicle, and is particularly suitable for measuring a communication environment along a railway line.

In recent railway systems, in order to maintain equipment and expand services for passengers, mobile communication is used to connect ground equipment and railway vehicles by wireless communication to transmit and receive data. In such wireless communication, radio wave interference occurs due to obstacles along the route, so that the traveling range in which the communication state is stable may be limited.

Conventionally, when transmitting data in an unstable communication state, it is common to divide the information capacity to be transmitted into fixed capacities and transmit the data in divided units. However, as the division capacity is made finer, the communication overhead increases and the transmission time increases, so it is necessary to appropriately determine the division unit according to the communication state.

Patent Document 1 proposes the following invention as a technique for detecting radio interference on a railway line. It is determined in advance by arranging a radio base station that transmits radio signals along the route and equipping the railway vehicle with a radio wave measuring device that detects radio interference along the route and a positioning device for grasping the position of the vehicle. It is an invention that measures the radio wave intensity at a certain point, records the measurement result in relation to the position information, and determines whether or not the measured radio wave strength is within a preset allowable range.

Further, in mobile communication other than the railway field, the following inventions are proposed in Patent Document 2. A radio wave intensity history by a wireless communication system including a radio wave strength measuring unit and a communication history / disconnection history holding unit that holds a history of radio field strength from the past to the present, a history of communication request amount, and a history of communication disconnection due to a timeout. It is an invention that avoids unnecessary disconnection and improves communication efficiency by predicting the future communication status from at least one of the history of communication volume and the history of communication volume and calculating the time interval until the timeout.

Japanese Unexamined Patent Publication No. 2017-188846 Japanese Unexamined Patent Publication No. 2006-67507

However, in the invention described in Patent Document 1, since the radio wave intensity measurement result is related only to the position information of the vehicle traveling on the route, the level of the received radio wave determined by statistically processing the measurement result. The threshold for determining the tolerance is to correctly determine whether the measured signal strength is within the preset tolerance when radio interference occurs due to factors such as weather, time of day, or sudden drop in signal strength. I can't judge.

On the other hand, in the invention described in Patent Document 2, the timeout time is extended in order not to disconnect the communication unnecessarily when the communication is temporarily interrupted when the communication is unstable, but the communication is not stable. If it lasts for a long time, the extended timeout will unnecessarily increase the overall communication time.

Therefore, in a form such as a railroad vehicle that follows the operation schedule and travels on the same route at a fixed time, communication is performed based on complex conditions such as vehicle position, weather, or time zone in order to improve communication efficiency and shorten communication time. It is necessary to calculate the possible capacity. It is considered that the invention described in Patent Document 1 only determines whether or not the current radio wave intensity is within the preset allowable range, and does not lead to the determination of the communicable capacity.

Focusing on the above-mentioned problems, it is an object of the present invention to improve communication efficiency and shorten communication time by predicting the communicable capacity from the communication status along the railway line.

In order to achieve the above-mentioned problems, as a communication environment measuring device mounted on a vehicle, a communication unit that performs data communication and measures the communication speed of the data communication, a position measuring unit that measures the traveling position of the vehicle, and a peripheral portion of the vehicle. The control unit includes a radio wave measurement unit that measures the radio field strength, a weather measurement unit that measures the weather around the vehicle, a clock unit that acquires the time, a recording unit that records information about the measurement, and a control unit. When the vehicle travels in a predetermined travel section, each measurement data by the communication unit, the position measurement unit, the radio wave measurement unit, and the weather measurement unit is recorded in the recording unit as the measurement result of the predetermined travel section together with the time acquired by the clock unit. At the same time, the most similar measurement results are obtained by reading out the measurement results of the predetermined travel section acquired in the past from the recording unit and collating them with respect to the measurement data and the time of the predetermined travel section acquired during the current travel of the vehicle. Is selected, and the communicable capacity of a predetermined traveling section during the current traveling is calculated based on the selected measurement results.

According to the present invention, the size and transmission time of data to be transmitted can be planned by calculating the communicable capacity for each section of the vehicle traveling route. Data with a large size is divided into data sizes suitable for the section and transmitted across multiple sections to reduce the number of transmission retries compared to batch transmission, and to improve communication efficiency and shorten communication time. Can be done.

It is a figure which shows the whole of the communication environment measurement system which concerns on this invention simply. It is a figure which shows the structure of the on-board device mounted on a railroad vehicle. It is a figure which shows the flowchart of the process which a control part executes. It is a figure which shows the flowchart of the present section measurement processing of step S6. It is a figure which shows the flowchart of the communicable capacity calculation process of step S5. It is a figure which shows the data format of the record stored in a recording part. It is a figure which shows an example of the calculation processing flow of a communicable capacity. It is a figure which shows an example of the measured value table used for calculating the communicable capacity. It is a figure explaining how to select the optimum record which matches the current measurement result.

Hereinafter, examples of the case where the communication environment measurement system according to the present invention is applied to a railway line will be described with reference to the drawings.

FIG. 1 is a diagram simply showing the entire communication environment measurement system according to the present invention.
As shown in FIG. 1, when a railroad vehicle 1 that transmits radio waves travels on a line 9 in which a section is set, the railroad vehicle 1 is used for each section, for example, radio waves 2 in section A and radio waves 2 in section B. The radio wave 4 is transmitted in the radio wave 3 and the section C. The mobile communication network 6 that has received these radio waves 2 to 4 transmits the data transmitted by the radio waves 2 to 4 to the ground device 8 via the radio waves 7 transmitted by the mobile communication network 6.

When the railway vehicle 1 travels in the section A, the section B, and the section C of the line 9 in order, the railroad vehicle 1 holds the communicable capacity calculated from the communication environment measured in advance for each section, and transmits the communicable capacity for each section by radio wave. Change the data capacity.

Here, as shown in FIG. 1, for example, the communicable capacity of the section A is medium, the communicable capacity of the section B is large, and the communicable capacity of the section C exists in the section C. It is determined that communication is not possible because communication is not possible due to the shield 5.

Therefore, regarding the data transmitted by the railroad vehicle 1, the data capacity is smaller than that of the section B as in the radio wave 2 when traveling in the section A, and the data is stored in the section A as in the radio wave 3 when traveling in the section B. The capacity is increased, and when traveling in the section C, data is not transmitted due to the influence of the shield 5 unlike the radio wave 4.

FIG. 2 is a diagram showing a configuration of an on-board device mounted on a railroad vehicle 1.
The on-board equipment includes a data input unit including a positioning device 10, a clock device 11, a radio wave measuring device 12, and a weather measuring device 13, a data input / output unit consisting of a recording unit 14 and a communication device 15, and the above devices. It is composed of a control unit 16 connected to.

First, the data input unit will be described.
The positioning device 10 inputs the traveling position data used for processing the traveling section of the railway vehicle 1 to the control unit 16.
The clock device 11 inputs time data used for processing the traveling time of the railway vehicle 1 to the control unit 16.
The radio wave measuring device 12 inputs radio wave intensity data used for processing the radio wave condition along the railway line to the control unit 16.
The weather measuring device 13 inputs the weather information data used for processing the weather in the area around the route to the control unit 16.

Next, the data input / output unit will be described.
The recording unit 14 inputs the communication environment measurement result for each section in a record having the data format shown in FIG. 6 from the control unit 16, and receives the measurement result for each section in response to a request from the control unit 16. The recorded record (FIG. 6) is output to the control unit 16.
In the communication device 15, transmission data is input from the control unit 16, and reception data and communication speed from the ground device 8 and the like are output to the control unit 16.

Then, the control unit 16 processes the input / output data from the devices and the like of reference numerals 10 to 15 described above, and calculates the communicable capacity for each section of the line 9.

FIG. 3 is a diagram showing a flowchart of processing executed by the control unit 16.
The control unit 16 executes a process of determining whether the communicable capacity of the traveling section can be calculated from the past records recorded in the recording unit 14 while the railway vehicle 1 is traveling on the section of the line 9. The main body that executes the processing according to this flowchart is the control unit 16, and the description of this main body is omitted in the following description of the flowchart.

In step S1, the traveling position is grasped.
In step S2, it is determined whether or not the vehicle is traveling from the traveling position input from the positioning device 10 (in other words, the presence or absence of the next section). If the vehicle is traveling (Y), the process proceeds to step S3, and if the vehicle is not traveling (N), the process ends.

In step S3, the recording unit 14 refers to the record of the current section in which the vehicle is running.
As a result of referring to the recording unit 14 in step S4, it is determined whether or not a record in the current section exists. If it exists (Y), the process proceeds to step S5, and if it does not exist (N), step S5 is skipped and the process proceeds to step S6.

In step S5, the communicable capacity in the current section is calculated (described later with reference to FIG. 5).
In step S6, the current interval measurement process is executed (described later with reference to FIG. 4).
After the execution of step S6 is completed, the process returns to step S1 and the above processing is repeated.

After all, the control unit 16 executes the current section measurement process until the running of the section is completed.

FIG. 4 is a diagram showing a flowchart of the current section measurement process in step S6.
The current section measurement process (step S6) is a process in which the control unit 16 measures the communication environment while the railway vehicle 1 is traveling on the section of the line 9. Since the main body that executes the process shown in this flowchart is the control unit 16, the description of this main body is omitted in the following description of the flowchart.

In step S26-1, the section name for measuring the communication environment is recorded in the section name (data item 18) of the record (FIG. 6) stored in the recording unit 14.
In step S26-2, the time acquired from the clock device 11 is recorded in the measurement start time (data item 19) of the record (FIG. 6) stored in the recording unit 14.

In step S27, the radio wave intensity of the current section is measured by the radio wave measuring device 12.
In step S28, the communication speed of the current section is measured by the communication device 15.
In step S29, the weather in the current section is measured by the weather measuring device 13.
In step S30, the running time is acquired from the clock device 11.
Here, the order of steps S27 to S30 is random, and the processing order of steps S27 to S30 may be arbitrary.

In step S31, the current traveling position is grasped by the positioning device 10.
In step S32, it is determined whether or not the traveling section has ended. If the traveling section is not completed (N), the process returns to step S27 and the process up to step S30 is repeated. Here, while the processes of steps S27 to S30 are repeated, each measurement data is stored in the memory, the average value is calculated excluding the abnormal value, and the average value is sequentially updated. When the traveling section is completed (Y), the process proceeds to step S33.

In step S33, the time acquired from the clock device 11 is recorded in the measurement end time (data item 20) of the record (FIG. 6) stored in the recording unit 14.

In step S34 and subsequent steps, each measurement result (mean value) from step S27 to step S30 is converted into the record format shown in FIG. 6 and recorded.

In step S34, it is determined whether or not the radio wave strength measured in step S27 is a communicable radio wave strength. If the radio wave strength is communicable (Y), the process proceeds to step S36, and if the radio wave strength is not communicable (N), in step S35, the communication availability (data item 22) of the record (FIG. 6) is "Not". It is recorded as "possible", and the current section measurement process (step S6) is terminated.

In step S36, "possible" is recorded in the communication availability (data item 22) of the record (FIG. 6).
In step S37, the communication speed measured in step S28 is recorded in the communication speed (data item 24) of the record (FIG. 6).

Next, in step S38, it is determined whether or not the weather measured in step S29 is sunny. In the case of fine weather (Y), "sunny" is recorded in the weather (data item 23) of the record (FIG. 6) in step S39, and in other cases (N), the record (FIG. 6) is recorded in step S40. Record "rain" in the weather (data item 23) and proceed to the next step.

In step S41, the time acquired in step S30 determines whether or not the time zone is early morning. In the case of early morning (Y), in step S43, “early morning” is recorded in the measurement time zone (data item 21) of the record (FIG. 6), and the current section measurement process (step S6) is terminated.

In the case other than early morning (N), in step S42, it is further determined whether or not the time zone is daytime. In the case of daytime (Y), in step S44, “daytime” is recorded in the measurement time zone (data item 21) of the record (FIG. 6), and the current section measurement process (step S6) is terminated.

In the case other than daytime (N), in step S45, “night” is recorded in the measurement time zone (data item 21) of the record (FIG. 6), and the current section measurement process (step S6) is terminated.

FIG. 5 is a diagram showing a flowchart of the communicable capacity calculation process in step S5.
The communicable capacity calculation process (step S5) is a process in which the control unit 16 calculates the communicable capacity of the section based on the record (FIG. 6) stored in the recording unit 14. Since the main body that executes the process shown in this flowchart is the control unit 16, the description of this main body is omitted in the following description of the flowchart.

In step S7, all the records of the current section are acquired from the recording unit 16.
In step S8, the weather measuring device 13 measures the weather in the current section during traveling.
In step S9, the current time is acquired from the clock device 11.
Here, the processing order of steps S8 and S9 may be arbitrary.

In the following steps S10 to S15, the record reference process is executed.
In the following step S16, it is determined whether or not all the records have been referred to. If there is a next record to be referred to (N), the record to be referred to is updated in step S17, the process returns to step S10, and the record reference processing of steps S10 to S15 is executed again. If there is no next record to be referred to (Y), the record selection process of the following steps S18 to S24 is executed.

After executing the processes of steps S18 to S24, in step S25, the communicable capacity is calculated from the selected record (described later), and the communicable capacity calculation process as step S5 is completed.

The code reference processing of steps S10 to S15 will be described retroactively.
In step S10, it is determined whether or not communication is possible with reference to the communication possibility (data item 22) of the record (FIG. 6). If there is a record that communication availability is "possible" (Y), the process proceeds to the next step S12, and if there is a record that communication availability is "impossible" (N), the communicable capacity of the current section is invalidated in step S11. Set to a value and end the communicable capacity calculation process (step S5).

In step S12, the weather (data item 23) of the record (FIG. 6) is referred to, and a match determination of the weather is made as compared with the current weather (S8). If they match (Y), the referenced record is recorded in the processing list (not shown) as a "record with matching weather" in step S13, and the process proceeds to step S14. If they do not match (N), step S13 is skipped and the process proceeds to step S14.

In step S14, the time zone match determination is made by referring to the measurement time zone (data item 21) of the record (FIG. 6) and comparing it with the current time acquired in step S9. If they match (Y), the referenced record is recorded in the processing list (not shown) as a "record whose time zone matches" in step S15, and the process proceeds to step S16. If they do not match (N), step S15 is skipped and the process proceeds to step S16.

After the above determination (presence / absence of reference to all records) in step S16 is completed, when the reference to all records is completed, the process proceeds to the record selection process of steps S18 to S24.

In step S18, it is determined whether or not the records recorded in the processing list in steps S13 and S15 have the same weather and time zone. If they match (Y), in step S21, a record whose weather and time zone match is selected and the process proceeds to step S25.

If the judgment in step S18 does not match (N), it is determined in step S19 whether or not only the weather matches. If only the weather matches (Y), in step S22, a record that matches only the weather is selected and the process proceeds to step S25.

If the determination in step S19 does not match (N), it is determined in step S20 whether or not only the time zone matches. If only the time zone matches (Y), in step S23, a record that matches only the time zone is selected and the process proceeds to step S25.

If the determination in step S20 does not match (N), the currently referenced record is selected in step S24, and the process proceeds to step S25.

Next, the process of calculating the communicable capacity in step S25 will be described.
FIG. 7 is a diagram showing an example of a communicable capacity calculation processing flow, and FIG. 8 is a diagram showing an example of a measured value table used for this calculation.

As shown in FIG. 7, the communicable capacity calculation process in step S25 is composed of four steps S25-1 to S25-4.
Step S25-1: Before executing the current section measurement process in step S6, the measured value table shown in FIG. 8 is created as a preliminary preparation. Here, in the measured value table, the measurement items that affect the radio field strength and the communication speed are registered, and the value that becomes the peak of the influence of the measurement items is binarized or ternated as the "threshold value", and the measurement items are also measured. The importance of is expressed as "weight" in, for example, 10 levels. In FIG. 8, other measurement items having the above-mentioned influence other than the weather or the time zone are described as, for example, "item A" to "item C".

Step S25-2: Write the measured value at the first run to the record.
Step S25-3: At the time of the second and subsequent runs, the degree of agreement using the measured value table with respect to the past records stored in the recording unit 14 with respect to the measured value (measurement result) at that time of running. Detect and select the record with the highest degree of matching as the best record.

A specific selection method will be described with reference to FIG. In the records extracted from the past records as matching the current measurement results (in FIG. 9, record 1 and record 2 as examples), the degree of matching is calculated for each data item having a weight. The calculated values of each data item calculated for the degree of matching are summed to obtain the degree of matching (= the total of the calculated values of the matching degree of each data item having a weight), and the record having the highest degree of matching is selected (FIG. 9). Then, since the degree of matching of record 1 is 10 and the degree of matching of record 2 is 5, record 1 is selected).

Step S25-4: The communicable capacity is calculated from the record selected in step S25-3. At this time, the scheduled running time of the running section is acquired from the running schedule before the start of running of the train. Normally, the operation schedule is the same as at the time of the previous measurement, but at the time of the target travel, if the operation schedule is delayed due to the influence of other lines, or if the operation schedule is scheduled to increase, the train speed will be increased. Therefore, it is assumed that a command to run for a shorter time than usual is issued, and this is to deal with such a case.

Specifically, the communication capacity is calculated from the acquired travel time with respect to the communication speed (Mbps) of the data item 24 of the record of FIG. For example, when the communication speed is 1 Mbps and the traveling time is 10 seconds, the communication capacity is 1 Mbps x 10 sec = 10 Mbit = 1.25 MB.

1 Railroad vehicles, 2, 3, 4 Radio waves transmitted by railroad vehicles, 5 Shields,
6 Mobile communication network, 7 Radio waves transmitted by mobile communication network,
8 ground equipment, 9 routes, 10 positioning equipment, 11 clock equipment, 12 radio wave measuring equipment,
13 weather measuring device, 14 recording unit, 15 communication device, 16 control unit,
17-record "record No.", 18-record data item "section name",
19 record data item "measurement start time",
20 record data item "Measurement end time",
21 record data item "measurement time zone",
22 Record data item "Communication availability",
23 record data item "weather", 24 record data item "communication speed"

Claims (10)

It is a communication environment measuring device mounted on a vehicle.
A communication unit that performs data communication and measures the communication speed of the data communication,
A position measuring unit that measures the running position of the vehicle, and
A radio wave measuring unit that measures the radio wave strength around the vehicle,
A weather measurement unit that measures the weather around the vehicle,
The clock part to get the time and
A recording unit that records information about measurements and
Equipped with a control unit
The control unit
When the vehicle travels in a predetermined travel section, the measurement results of the predetermined travel section together with the time when the measurement data by the communication unit, the position measurement unit, the radio wave measurement unit, and the weather measurement unit are acquired by the clock unit. As well as recording in the recording unit
The most similar said by reading out each measurement result of the predetermined traveling section acquired in the past from the recording unit and collating with each measurement data and time of the predetermined traveling section acquired during the current traveling of the vehicle. Each measurement result is selected, and the communicable capacity of the predetermined travel section at the time of the current travel is calculated based on the selected measurement result and the scheduled travel time of the predetermined travel section acquired from the operation schedule. A communication environment measuring device characterized by this. The communication environment measuring device according to claim 1.
If the recording unit does not have the measurement results of the predetermined travel section acquired in the past, the control unit may use the measurement data of the predetermined travel section acquired during the current travel as the measurement results of the predetermined travel section. A communication environment measuring device characterized by recording in a recording unit. The communication environment measuring device according to claim 1 or 2.
The control unit determines a measurement time zone separately from the time acquired from the clock unit into early morning, daytime, and nighttime, and uses the measurement data and the measurement result as one of the communication environment measurement devices. .. The communication environment measuring device according to any one of claims 1 to 3.
The control unit is a communication environment measuring device characterized in that the weather measured by the weather measuring unit is determined separately for sunny and rainy, and used as one of the measured data and the measured result. The communication environment measuring device according to any one of claims 1 to 4.
The control unit is a communication environment measuring device, characterized in that the communicable capacity is calculated only when the radio wave strength measured by the radio wave measuring unit is a communicable radio wave strength. The communication environment measuring device according to any one of claims 1 to 5.
Among the measurement results of the predetermined traveling section, the measurement results that affect the communication speed and the radio field intensity other than the measurement results of the communication speed and the radio wave intensity are weighted.
The weighting is applied when the control unit reads and collates each measurement result of the predetermined travel section acquired in the past from the recording unit with respect to each measurement data of the predetermined travel section acquired during the current travel. The measurement result is a communication environment measuring device, characterized in that the most similar measurement result is selected by using the weighted measurement result. A railway vehicle equipped with the communication environment measuring device according to any one of claims 1 to 6. When the vehicle travels in a predetermined travel section, the communication speed of data communication performed by the vehicle, the traveling position of the vehicle, the radio wave intensity around the vehicle, and the weather around the vehicle are measured, and the time at the time of the measurement is acquired. The first step to do and
A second step of recording each measurement data acquired in the first step and the time at the time of the measurement as each measurement result,
It is most similar by reading out and collating each measurement result of the predetermined travel section acquired in the past recorded in the past with respect to each measurement data of the predetermined travel section acquired during the current travel of the vehicle and the time at the time of measurement. The third step of selecting each measurement result and
Based on the measurement results selected in the third step and the scheduled travel time of the predetermined travel section acquired from the operation timetable, the communicable capacity of the predetermined travel section during the current travel is calculated. A method for measuring a communication environment of a vehicle having 4 steps. The method for measuring the communication environment of a vehicle according to claim 8.
A method for measuring a communication environment of a vehicle, characterized in that the third and fourth steps are not executed when the measured radio wave strength is a radio wave strength at which communication is impossible. The method for measuring the communication environment of a vehicle according to claim 8 or 9.
Among the measurement results of the predetermined traveling section, there is a prior step of weighting the measurement results that affect the communication speed and the radio field intensity other than the communication speed and the radio wave intensity.
The third step is characterized in that when the recorded measurement results of the predetermined traveling section acquired in the past are read out and collated, the weighted measurement results are used for the weighted measurement results. How to measure the communication environment of the vehicle.

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