Data transfer apparatus and data transfer method

Abstract

The present application provides a kind of data transmission device, which can inhibit the occurrence of overflow, while avoiding the reduction of sensor data communication speed in the area where wireless communication line speed is low.Data transmission device includes: data acquisition unit (301), which obtains sensor data detected by sensor by first data communication speed;Communication unit (300,400), which sends the obtained sensor data to external server by second data communication speed;Storage amount calculation unit (304,404), which calculates the time evolution of the predicted storage amount of the obtained sensor data to memory using the first data communication speed and the second data communication speed;And determination unit (305,405), which determines whether the sensor data stored in the memory is overflowed based on the time evolution of the predicted storage amount.

Description

Technical Field

[0001] This disclosure relates to a data transmission apparatus and a data transmission method. Background Technology

[0002] A system is employed to collect data acquired by sensors mounted on a vehicle via a wireless communication line, and to use the collected data for driving assistance in other vehicles. As a technology that can be utilized in such a system, Patent Document 1 discloses a technique in which an onboard device obtains line speed information of the communication line in a predetermined driving area of ​​the vehicle from a server, and based on the obtained line speed information, controls the sensor information collection speed when sensor information detected by the onboard sensors is input into the onboard device's memory (transmission buffer). More specifically, when the vehicle is traveling in an area with low line speed, the sensor information collection speed is controlled to be slower (see claim 1 of Patent Document 1). Figure 6 and Figure 7 ).

[0003] Existing technical documents

[0004] Patent documents

[0005] Patent Document 1: International Publication No. 2019 / 188343 Summary of the Invention

[0006] The technical problem that the invention aims to solve

[0007] According to the technology in Patent Document 1, since the sensor information collection speed is controlled based on the line speed information of the wireless communication line in the predetermined driving area of ​​the vehicle, overflow in the memory can be suppressed.

[0008] However, according to the technology in Patent Document 1, since the sensor information collection speed depends on the line speed, the following problem exists: in tunnels or mountain sections where the line speed is 0 or low, the sensor information collection speed will inevitably decrease.

[0009] The present invention was made to solve the above-mentioned problems. One aspect of the embodiments is to provide a data transmission device that can suppress the occurrence of overflow and avoid the reduction of sensor data communication speed in areas where the wireless communication line speed is low.

[0010] Technical solutions to solve technical problems

[0011] One side of the data transmission apparatus of the embodiment includes: a data acquisition unit that acquires sensor data detected by a sensor at a first data communication speed; a communication unit that transmits the acquired sensor data to an external server at a second data communication speed; a storage capacity calculation unit that uses the first data communication speed and the second data communication speed to calculate the time shift of the storage capacity of sensor data stored in a memory used to temporarily store sensor data received from the sensor; and a determination unit that determines whether the sensor data stored in the memory has overflowed based on the time shift of the storage capacity.

[0012] Invention Effects

[0013] One side of the data transmission device according to the embodiment can suppress overflow and avoid reducing the data communication speed of sensors in areas where the line speed is low. Attached Figure Description

[0014] Figure 1 This is a diagram illustrating a structural example of the data transmission system in Implementation Method 1.

[0015] Figure 2 This is a diagram illustrating a hardware structure example of the data transmission device in Embodiment 1.

[0016] Figure 3 This is a block diagram illustrating the functional structure of the data transmission device in Embodiment 1.

[0017] Figures 4A-4E It is a graph that represents the amount of data stored in the memory over time. Figure 4A It is a diagram that shows the path a vehicle takes from its starting point to its destination. Figure 4B It is a graph representing the time-varying predicted mobile data communication speed along the travel path. Figure 4C It means to Figure 4B A graph showing the time progression of predicted mobile data communication speeds by converting the distance axis to the time axis. Figure 4D This is a graph representing the data communication speed of the sensor. Figure 4E Yes Figure 4C and Figure 4D The graph of integrating the difference.

[0018] Figures 5A to 5C It is a graph used to represent the time transition of predicted memory storage when the vehicle is traveling at a speed of 50 km / h. Figures 5D to 5F It is a graph used to represent the time-varying amount of predicted storage in a vehicle traveling at 100 km / h. Figure 5AIt is a graph representing the time progression of predicted mobile data communication speeds, with the horizontal axis represented as time, using predicted vehicle speed values ​​along the driving path. Figure 5B This is a graph representing the data communication speed of the sensor. Figure 5C It is a graph representing the time transition of the predicted storage capacity. Figure 5D It is a graph representing the time progression of predicted mobile data communication speeds, with the horizontal axis representing time. Figure 5E This is a graph representing the data communication speed of the sensor. Figure 5F It is a graph representing the time transition of the predicted storage capacity.

[0019] Figure 6 This is an example of a sensor information table.

[0020] Figure 7 This is a flowchart of the data transmission device in Implementation Method 1.

[0021] Figure 8 This is a flowchart of the subroutine for calculating and processing the sensor data communication speed in Implementation Method 1.

[0022] Figure 9 This is a block diagram illustrating the functional structure of the data transmission device in Embodiment 2.

[0023] Figure 10 This is a flowchart illustrating the subroutine for calculating and processing the sensor data communication speed in Implementation Method 2. Detailed Implementation

[0024] Hereinafter, various embodiments of the present invention will be described in detail with reference to the accompanying drawings. Furthermore, structural elements labeled with the same reference numerals throughout the drawings have the same or similar structures or functions.

[0025] Implementation method 1.

[0026] <Structure>

[0027] (Data transmission system)

[0028] Reference Figure 1 The structure of a data transmission system equipped with a data transmission device will be described using an example. For instance... Figure 1 As shown, the data transmission system 10 includes a data transmission device 100 and a server 102, and the data transmission device 100 and the server 102 are configured to communicate via a mobile communication line. Figure 1As shown, the data transmission device 100 can be mounted on a mobile vehicle 103, for example. The vehicle 103 can be a human-driven vehicle or an autonomous vehicle. Alternatively, the vehicle 103 can be a mobile body such as an autonomous robot without a pre-arranged passenger. The data transmission device 100 acquires data from multiple sensors 101-1 to 101-n (hereinafter referred to as "sensors 101") equipped on the vehicle 103, and transmits the acquired data to the server 102 via a mobile communication line. Examples of sensors 101 include: sensors for detecting the surrounding or internal conditions of the vehicle 103, such as cameras, LiDAR, and millimeter-wave radar; and sensors for determining the driving position of the vehicle 103, such as GPS (Global Positioning System) sensors and GNSS (Global Navigation Satellite System) sensors. Examples of mobile communication lines include communication lines based on standards such as LTE (Long Term Evolution), 3G (Generation), 4G, or 5G.

[0029] (Data transmission device)

[0030] Next, refer to Figure 2 The hardware structure of the data transmission device 100 will be described as an example. Figure 2 As shown, the data transmission device 100 includes an external network I / F 200, a processor 201, a memory 202, and an internal network I / F 203. The processor 201 is connected to the external network I / F 200, the memory 202, and the internal network I / F 203.

[0031] (External Network I / F)

[0032] External network I / F200 is a wireless communication interface of data transmission device 100 for connecting to an external communication network. When data transmission device 100 is mounted on vehicle 103, external network I / F200 connects to the external communication network of vehicle 103 and communicates with a device (not shown) connected to the communication network.

[0033] (Processor, memory)

[0034] The processor 201 performs the various functions described later by reading one or more programs stored in the memory 202 and executing them. In addition to storing the executable program executed by the processor 201, the memory 202 also provides a storage device for temporarily storing sensor data acquired by the sensor 101. The storage device ensures that its maximum storage capacity is set by executing the executable program. The maximum storage capacity can be set based on user input. Furthermore, the data transmission device 100 can also obtain information about the maximum storage capacity from the server 102 and update the maximum storage capacity setting. The memory 202 can be a non-volatile memory such as a ROM (Read Only Memory) 202a that stores the executable program, or a volatile memory such as a RAM (Random Access Memory) 202b that temporarily stores the executable program and the data referenced by the executable program. The memory 202 can be located externally to the data transmission device 100.

[0035] Alternatively, a dedicated processing circuit can be used instead of the processor 201. In this case, the memory is used as a medium to provide storage for temporarily storing sensor data, and the maximum storage capacity of the memory is set by the processing circuit. The maximum storage capacity of the memory can be set based on user input. Additionally, the data transmission device 100 can obtain information about the maximum storage capacity of the memory from the server 102 and update the setting of the maximum storage capacity. Examples of processing circuits include single circuits, composite circuits, programmed processors, parallel programmed processors, ASICs (Application Specific Integrated Circuits), FPGAs (Field-Programmable Gate Arrays), or combinations thereof.

[0036] (Internal Network I / F)

[0037] The internal network I / F 203 is a wired communication interface used to communicate with devices used in conjunction with the data transmission device 100. When the data transmission device 100 is mounted on the vehicle 103, the internal network I / F 203 communicates with sensors mounted on the vehicle 103, such as cameras, LiDAR, or GPS. Examples of internal network I / F 203 include sensor I / F, Ethernet, and CAN.

[0038] Next, refer to Figure 3 The functional structure of the data transmission device 100 will be explained. For example... Figure 3As shown, the data transmission device 100 includes a communication unit 300, a data acquisition unit 301, a driving route notification unit 302, a vehicle speed notification unit 303, a storage capacity calculation unit 304, a judgment unit 305, a data processing unit 306, and a storage control unit 307.

[0039] (Data Acquisition Department)

[0040] The data acquisition unit 301 acquires sensor data from various sensors mounted on the vehicle, such as cameras, LiDAR, and GPS. The data acquisition unit 301 then sends the acquired sensor data to the data processing unit 306. The data acquisition unit 301 operates via the internal network I / F 203.

[0041] (Data Processing Department)

[0042] The data processing unit 306 receives sensor data from the data acquisition unit 301. Additionally, as described later, the data processing unit 306 receives processing information related to the processing of the sensor data from the determination unit 305. Examples of processing information include information related to period or frequency, information related to resolution, and information related to compression ratio. The data processing unit 306 processes the sensor data based on this processing information. Examples of processing include sparsity processing, resolution reduction, and compression ratio modification. For example, upon receiving information related to period or frequency, the data processing unit 306 performs sparsity processing on the sensor data based on this information. For example, upon receiving information related to resolution, the data processing unit 306 reduces the resolution of the sensor data based on this information. For example, upon receiving information related to compression ratio, the data processing unit 306 compresses the sensor data based on this information. The data processing unit 306 then sends the sensor data obtained from the processing based on the processing information to the storage control unit 307. The data processing unit 306 is implemented, for example, by reading an executable program from the memory 202 and having it executed by the processor 201. The data processing unit 306 may also be implemented using processing circuitry not shown.

[0043] (Storage Control Unit)

[0044] The storage control unit 307 stores the processed sensor data received from the data processing unit 306 into the storage of the memory 202. Furthermore, the storage control unit 307 notifies the storage capacity calculation unit 304 of information related to the storage status, such as the maximum storage capacity of the storage and the amount of sensor data stored in the storage. Additionally, in order to send the data stored in the storage of the memory 202 to the server 102, the storage control unit 307 notifies the communication unit 300 to send the sensor data of the target device to the server 102. The storage control unit 307 can be implemented, for example, by reading an executable program from the memory 202 and having it executed by the processor 201. The storage control unit 307 can also be implemented using processing circuitry (not shown).

[0045] (Ministry of Communications)

[0046] The communication unit 300 is a communication unit that communicates with external devices via the communication network NW. The communication unit 300 transmits sensor data of the transmission target notified by the storage control unit 307 to the server 102 via the communication network NW. Additionally, the communication unit 300 transmits mobile communication-related information received from the server 102 to the storage calculation unit 304. The communication unit 300 is implemented via the external network I / F 200.

[0047] (Route Notification Department)

[0048] The driving route notification unit 302 acquires the predetermined driving route of the vehicle and sends the acquired driving route to the vehicle speed notification unit 303 and the storage calculation unit 304. The driving route calculation can be performed by a navigation device (not shown) mounted in the vehicle, or by an external server (e.g., server 102). The navigation device (not shown) and the data transmission device 100 can also be integrated. The driving route notification unit 302 can be implemented, for example, by reading the execution program from the memory 202 and executing it by the processor 201. The driving route notification unit 302 can also be implemented by a processing circuit (not shown).

[0049] (Speed ​​Notification Department)

[0050] The vehicle speed notification unit 303 predicts the vehicle speed on the driving path obtained from the driving path notification unit 302 and sends it to the storage calculation unit 304. The vehicle speed prediction is calculated, for example, based on the legal speed limit on the driving path. Regarding the vehicle speed prediction, if there is past driving history on that driving path, it can also be calculated based on the driving speed at which the vehicle was driven on that driving path in the past. The vehicle speed notification unit 303 is implemented, for example, by reading the executable program from the memory 202 and having it executed by the processor 201. The vehicle speed notification unit 303 can also be implemented using processing circuitry not shown.

[0051] (Storage Calculation Department)

[0052] The storage capacity calculation unit 304 maintains a sensor information table containing values ​​related to parameters such as communication speed and cycle time of various sensors, and calculates the predicted storage capacity of sensor data stored in the memory 202. Furthermore, the sensor communication speed is sometimes referred to as the sensor data communication speed below. The storage capacity calculation unit 304 is implemented, for example, by reading an execution program from the memory 202 and executing it with the processor 201. The storage capacity calculation unit 304 may also be implemented using processing circuitry not shown.

[0053] Figure 6 This is a diagram representing an example of a sensor information table. (For example...) Figure 6 As shown, in the sensor information table, enter default values ​​for each item related to the object sensor: communication speed (i.e., sensor data communication speed), period or frequency, resolution, and compression ratio. This will be discussed later. Figure 8 In step B5 of the flowchart, if the sensor data communication speed is changed, the storage calculation unit 304 rewrites the default value to suit the changed sensor data communication speed. When the vehicle arrives at its destination, the table value returns to the default value.

[0054] In order to calculate the predicted storage capacity, the storage capacity calculation unit 304 uses information received from the communication unit 300, the storage control unit 307, the driving route notification unit 302, and the vehicle speed notification unit 303, in addition to the information from the sensor information table.

[0055] Here, refer to Figures 4A-4E The method for calculating the predicted storage capacity is explained. Figure 4A It is a diagram showing the route the vehicle takes from the starting point to the destination, obtained from the route notification unit 302. Figure 4B It is a graph showing the time progression of the predicted mobile data communication speed along the travel path, obtained from the communications unit 300. Figure 4C It uses the predicted vehicle speed value along the driving path obtained from the vehicle speed notification unit 303 to indicate that... Figure 4B A graph showing the time progression of predicted mobile data communication speeds is presented by converting the distance axis to the time axis. This is done by dividing the distance by the predicted vehicle speed value, thus converting from the distance axis to the time axis. Figure 4D It is a graph representing the data communication speed of a certain sensor, such as an external camera, obtained from the sensor information table. Figure 4E Yes Figure 4C and Figure 4D The graph is obtained by integrating the difference. That is, it is from... Figure 4D Sensor data communication speed minus Figure 4C The graph is a time integral of the value obtained from predicting mobile data communication speed. Figure 4EIn the diagram, the solid line represents the integral value, and the dashed line represents the maximum storage capacity of the memory. Data overflow occurs when the solid line exceeds the dashed line.

[0056] Here, refer to Figures 5A to 5F The explanation will shift the time frame of the predicted mobile data communication speed from Figure 4B Distance axis converted Figure 4C The reason for the timeline. Figures 5A to 5C It is a graph used to represent the time transition of predicted memory storage when the vehicle is traveling at a speed of 50 km / h. Figures 5D to 5F It is a graph used to represent the time-varying amount of predicted storage in a vehicle traveling at 100 km / h. Figure 5A and Figure 5D These are graphs representing the time progression of predicted mobile data communication speeds, with the horizontal axis representing time, using predicted vehicle speed values ​​along the driving path. Figure 5B and Figure 5E These are graphs representing the data communication speeds of sensors (such as exterior cameras). Figure 5C and Figure 5F These are graphs representing the time shift of predicted storage capacity. Even with the same travel distance, different vehicle speeds result in different arrival times. That is, slower speeds take longer to reach the destination. Therefore, if the predicted mobile data communication speed is consistently slower than the sensor data communication speed, sensor data will continuously accumulate in storage, sometimes leading to overflow. For example, as... Figures 5D to 5F As shown, no overflow will occur when the vehicle is traveling at a speed of 100 km / h. However, as... Figures 5A to 5C As shown, when the vehicle is traveling at a speed of 50 km / h, compared to when the vehicle is traveling at a speed of 100 km / h, the sensor data communication speed is faster than the predicted mobile data communication speed for a longer period of time, thus increasing the amount of sensor data stored in the storage and causing overflow. As in the embodiments of this disclosure, by converting the predicted mobile data communication speed along the driving path from a distance axis to a time axis, it is possible to accurately determine whether an overflow has occurred.

[0057] In this way, the storage capacity calculation unit 304 uses information from the sensor information table, as well as information received from the communication unit 300, the driving route notification unit 302, and the vehicle speed notification unit 303, to calculate the predicted storage capacity. Additionally, the storage capacity calculation unit 304 can also calculate a later predicted storage capacity based on the storage state (the amount of sensor data stored in the storage) at a certain moment received from the storage control unit 307.

[0058] return Figure 3The storage capacity calculation unit 304 sends the time-shift information of the predicted storage capacity and the information of the maximum storage capacity of the memory to the determination unit 305. Additionally, the storage capacity calculation unit 304 sends the values ​​of the parameters of various sensors in the sensor information table to the determination unit 305. Furthermore, as described later, if the determination unit 305 receives a notification indicating that an overflow has occurred in the memory of the memory 202, the storage capacity calculation unit 304 calculates the total communication speed without an overflow. This calculation method will be explained later with reference to the flowchart. The storage capacity calculation unit 304 rewrites the values ​​of each parameter in the sensor information table to obtain the calculated total communication speed, and uses the rewritten values ​​to recalculate the predicted storage capacity of the sensor data stored in the memory of the memory 202. The recalculated predicted storage capacity is output to the determination unit 305.

[0059] (Judgment Department)

[0060] The determination unit 305 determines whether an overflow has occurred based on the time-varying information of the predicted storage capacity output from the storage capacity calculation unit 304 and the information of the maximum storage capacity of the memory. For example, if the predicted storage capacity exceeds the maximum storage capacity of the memory, an overflow is determined to have occurred; if the predicted storage capacity is less than the maximum storage capacity of the memory, an overflow is determined not to have occurred. If an overflow is determined to have occurred, the storage capacity calculation unit 304 is notified of the overflow. If an overflow is determined not to have occurred, the processing information (period, frequency, resolution, or compression ratio) of various sensors in the sensor information table, i.e., the parameter values, are sent to the data processing unit 306. The determination unit 305 can be implemented, for example, by reading the execution program from the memory 202 and having it executed by the processor 201. The determination unit 305 can also be implemented using processing circuitry not shown.

[0061] <Action>

[0062] Next, refer to Figure 7 and Figure 8 The operation of the data transmission device 100 will be explained. Figure 7 This is a flowchart of the data transmission device 100. Figure 8 It means Figure 7 The flowchart for the sensor data communication speed calculation and processing subroutine in step A3 is shown. Figure 7 In addition to performing step A1 at the start of vehicle travel, step A1 is also performed when the vehicle changes its route during travel. Steps A2 through A5 are executed periodically during travel, except at the start of travel. The period can be arbitrarily changed, or period-related information can be received from server 102 and the period can be set based on the received information. Each step is described in detail below.

[0063] In step A1, the storage calculation unit 304 obtains the predicted mobile data communication speeds for each area containing the driving path from the server 102 via the communication unit 300. For example, the server 102 pre-stores the predicted mobile data communication speeds, location information, and time information of multiple vehicles that have previously traveled along the driving path, and uses this data stored in the server 102 to predict the predicted mobile data communication speeds. The predicted mobile data communication speeds can be calculated using other methods. The timing for obtaining the predicted mobile data communication speeds is at the start of the journey. The predicted mobile data communication speeds are not obtained during the journey unless there is a path change.

[0064] In step A2, the vehicle speed notification unit 303 uses the driving path information input from the driving path notification unit 302 to calculate a predicted vehicle speed value associated with the location information on the driving path. The predicted vehicle speed value is calculated based on the legal speed limit of the road on the driving path or the driver's driving tendency. The vehicle speed prediction is performed, for example, at the start of driving. The vehicle speed prediction can be performed periodically during driving, or it can be triggered by accident information on the driving path. The period is, for example, a time interval of 30 minutes or 1 hour. The period can be set to any value, or the period information can be obtained from the server 102. In addition, the trigger information can also be obtained from the server 102. The vehicle speed notification unit 303 sends the calculated predicted vehicle speed value to the storage calculation unit 304. If the predicted vehicle speed value calculated at a predetermined period changes compared to the previously calculated predicted vehicle speed value, the vehicle speed notification unit 303 sends the newly calculated predicted vehicle speed value to the storage calculation unit 304. By providing new predicted vehicle speed values ​​in the event of changes in predicted vehicle speed values, the accuracy of the time-lapse prediction of the amount of stored data can be maintained even when the vehicle speed changes during driving due to events such as traffic jams.

[0065] In step A3, the sensor data communication speed is calculated. (Refer to...) Figure 8 The details of the calculation and processing of sensor data communication speed are explained. Figure 8 In step B2, for the predicted mobile data communication speeds in each area obtained from server 102, storage calculation unit 304 uses the predicted vehicle speed values ​​input from vehicle speed notification unit 303, such as... Figure 4C As shown, the time progression of the predicted mobile data communication speed is calculated. Specifically, the storage calculation unit 304 calculates the predicted mobile data communication speed, represented by the distance axis, obtained from the server 102, by dividing the predicted vehicle speed value. Then, as... Figure 4D The diagram shows the time transition used to calculate the sensor data communication speed. The sensor data communication speed is referenced to... Figure 6 The information is obtained from a sensor information table as shown. The storage capacity calculation unit 304 obtains the information from... Figure 4D Sensor data communication speed minus Figure 4C The value obtained from predicting mobile data communication speed is integrated over time, thus... Figure 4E The time shift of the predicted storage capacity is calculated in this way. The storage capacity calculation unit 304 provides the calculated time shift of the predicted storage capacity to the determination unit 305.

[0066] In step B3, the determination unit 305 uses the time shift of the predicted memory storage amount received from the storage amount calculation unit 304 to determine whether an overflow has occurred in the memory. Figure 4E The dashed line represents the maximum storage capacity of the memory. Whether an overflow occurs is determined based on whether the calculated predicted storage capacity exceeds the maximum storage capacity. Specifically, an overflow is considered to have occurred if the predicted storage capacity exceeds the maximum storage capacity, and an overflow is considered not to have occurred if the predicted storage capacity does not exceed the maximum storage capacity.

[0067] If it is determined that no overflow will occur, the process branches off in step B4 and proceeds to step B6. In step B6, the determination unit 305 outputs the value of the sensor information table to the data processing unit 306.

[0068] If an overflow is determined to have occurred, the process branches off in step B4 and proceeds to step B5. In step B5, the determination unit 305 notifies the storage calculation unit 304 of the overflow. The storage calculation unit 304 calculates the sensor data communication speed (third data communication speed) in case an overflow does not occur.

[0069] The sensor data communication speed (third data communication speed) is calculated according to the following steps. During the time from the start of travel to the arrival at the destination, the amount of data exceeding the maximum storage capacity of the storage device is integrated, and the total amount exceeding the maximum storage capacity of the storage device (hereinafter referred to as "total excess") is calculated. On the other hand, during the time from the start of travel to the arrival at the destination, the total amount of sensor data transmitted from the sensor input to the storage device at the original sensor data communication speed is calculated. Then, the sensor data communication speed is calculated according to the following formula (1).

[0070] Sensor data communication speed =

[0071] [Total data transmitted by the sensor - (Total data exceeded + α)] / Travel time ... Equation (1)

[0072] That is, the storage capacity calculation unit 304 subtracts the amount obtained by adding the excess amount in the storage to an arbitrary value α from the total amount of data transmitted by the sensor, and divides the subtracted value by the travel time from the start of travel to the arrival at the destination, thereby calculating the sensor data communication speed. The storage capacity calculation unit 304 adjusts the storage capacity based on the calculated sensor data communication speed. Figure 6 The communication speed corresponding to the sensor information table.

[0073] Furthermore, the storage calculation unit 304 updates the processing information in the sensor information table to obtain the calculated sensor data communication speed. That is, the storage calculation unit 304 changes the values ​​of all or some of the items related to period or frequency, resolution, and compression rate to obtain the calculated sensor data communication speed. For example, the frame rate of the camera is changed from 30 [fps] to 20 [fps]. In the case of multiple sensors, the sensor data communication speed is sequentially reduced starting with the sensor with the lowest priority, resulting in a sensor data communication speed (total value) that does not overflow. An upper limit value can be set for the reduction magnitude of each sensor, and a minimum value can be set for the communication speed of each sensor. Priority can be determined according to each application or obtained from the server 102. In this way, by processing sensor data based on sensor priority, the amount of data from low-importance sensors can be suppressed, thus maintaining the quality of high-importance sensor data as much as possible. If the storage calculation unit 304 performs step B2 again and the determination unit 305 performs step B3 again without overflow (no in step B4), the determination unit 305 outputs the latest period or frequency, resolution, and compression ratio values ​​of each sensor to the data processing unit 306 (step B6), and the processing returns to... Figure 7 In the main program.

[0074] In step A4, the data processing unit 306 processes the sensor data provided by the data acquisition unit 301 using the values ​​of period or frequency, resolution, and compression ratio provided by the determination unit 305 from the storage calculation unit 304. For example, when receiving information related to period or frequency, the data processing unit 306 performs sparsity processing on the sensor data based on this information. For example, when receiving information related to resolution, the data processing unit 306 reduces the resolution of the sensor data based on this information. For example, when receiving information related to compression ratio, the data processing unit 306 compresses the sensor data based on this information. The data processing unit 306 then sends the processed sensor data to the storage control unit 307.

[0075] In step A5, the storage control unit 307 stores the received sensor data in the storage.

[0076] In step A6, the storage control unit 307 sends the sensor data stored in the storage during driving to the server 102 via the communication unit 300.

[0077] According to the data transmission apparatus 100 described above, the storage capacity calculation unit 304 uses the speed at which sensor data detected by the sensor is acquired (first data communication speed) and the speed at which the acquired sensor data is sent to the server 102 (second data communication speed) to calculate the time shift of the predicted storage capacity of the sensor data acquired by the data acquisition unit 301 to the memory of the memory 202. Furthermore, the determination unit 305 determines whether the sensor data stored in the memory of the memory 202 has overflowed based on the time shift of the predicted storage capacity. Thus, by predicting the storage capacity of the sensor data stored in the memory and determining whether an overflow has occurred, it is possible to avoid a decrease in sensor data communication speed in areas where the wireless communication line speed is low. That is, even if it is predicted that movement will occur in an area where the wireless communication line speed is low, if the predicted storage capacity is low and the memory has ample storage, it is determined that an overflow will not occur, thereby preventing a decrease in sensor data communication speed in areas where the wireless communication line speed is low.

[0078] Implementation method 2.

[0079] In Implementation 1, since predicted values ​​are used for both vehicle speed and mobile communication speed, discrepancies between predicted and measured values ​​may occur. Therefore, in Implementation 2, measured values ​​of vehicle speed and mobile communication speed are used to correct the sensor data communication speed, improving the accuracy of predicting the time-lapse of the storage capacity. Hereinafter, refer to... Figure 2 , Figure 6 , Figure 9 as well as Figure 10 The data transmission device 500 of Embodiment 2 will be described. Furthermore, descriptions of parts that are repeated in Embodiment 1 will be omitted.

[0080] <Structure>

[0081] like Figure 9 As shown, the data transmission device 500 is the same as in Embodiment 1, including a data acquisition unit 301 and a driving route notification unit 302. Furthermore, the data transmission device 500 also includes a vehicle speed notification unit 403, a storage capacity calculation unit 404, a determination unit 405, a data processing unit 406, a storage control unit 407, and a communication unit 400. The hardware structure of the data transmission device 500 is the same as in Embodiment 1, for example, it can be... Figure 2 The structure shown is used to achieve this.

[0082] (Ministry of Communications)

[0083] The communication unit 400 obtains from the server 102 the measured value of the actual amount of data sent from the vehicle's communication unit 400 to the server 102 during a certain period of time while in motion (i.e., the value of the fourth data communication speed), information about the time when the data was sent to the server 102, and information about the location where the data was sent to the server 102 (hereinafter, this information is collectively referred to as "actual mobile data communication speed information"). The communication unit 400 sends the actual mobile data communication speed information obtained from the server 102 to the storage calculation unit 404.

[0084] (Speed ​​Notification Department)

[0085] The vehicle speed notification unit 403 stores the measured vehicle speed along the travel path, the time information during travel, and the location information during travel (hereinafter, this information is collectively referred to as "actual vehicle speed information") in the memory 202. Then, the vehicle speed notification unit 403 sends the stored actual vehicle speed information to the storage calculation unit 404 at predetermined intervals. For example, it can send it at predetermined intervals every 5 minutes or every 10 minutes, or it can send it at predetermined intervals when passing through nodes of different links along the travel path.

[0086] (Storage Calculation Department)

[0087] The storage capacity calculation unit 404 uses the actual mobile data communication speed information obtained from the communication unit 400 and the actual vehicle speed information obtained from the vehicle speed notification unit 403 to calculate the correction sensor data communication speed. An example calculation is shown below. First, the scales of each piece of information are matched. For example, the time information of the actual mobile data communication speed information and the time information of the actual vehicle speed information are matched to ensure that the time axis of the measured vehicle speed, the time axis of the measured mobile data communication speed, and the time axis of the predicted storage capacity calculated in step B2 are consistent. As another example, the location information of the actual mobile data communication speed information and the location information of the actual vehicle speed information can be matched to ensure that the measurement point of the measured vehicle speed, the measurement point of the measured mobile data communication speed, and the measurement point of the predicted storage capacity calculated in step B2 are consistent.

[0088] After this scaling adjustment, the values ​​of each variable are substituted into the right side of equation (2) to calculate the corrected sensor data communication speed. Furthermore, the value of the sensor data communication speed uses... Figure 6 The value of the communication speed in the sensor information table.

[0089] Corrected sensor data communication speed =

[0090] Sensor data communication speed × (actual vehicle speed / predicted vehicle speed) +

[0091] α × (Measured mobile data communication speed – Predicted mobile data communication speed)

[0092] ...Formula (2)

[0093] In equation (2), the coefficient α is a coefficient that changes according to the characteristics of roads such as tunnels and mountainous areas.

[0094] In the first term on the right side of equation (2), the predicted vehicle speed is corrected using the measured vehicle speed value. In the second term on the right side, the predicted mobile data communication speed (the value of the 4th data communication speed) is corrected using the measured mobile data communication speed value (the value of the 2nd data communication speed). Using these correction values, the corrected sensor data communication speed is calculated.

[0095] After calculating the corrected sensor data communication speed, the storage capacity calculation unit 404 changes the value of the communication speed column in the sensor information table. Furthermore, the storage capacity calculation unit 404 changes the sensor's period or frequency, resolution, or compression ratio in the sensor information table to match the calculated sensor data communication speed. Additionally, using the corrected sensor data communication speed, the storage capacity calculation unit 404, similar to the case in Embodiment 1, recalculates the time shift of the predicted storage capacity after the moment the corrected value of the sensor data communication speed is calculated. In addition to the information on the time shift of the corrected predicted storage capacity, the storage capacity calculation unit 404 also sends the modified sensor information table information to the determination unit 405.

[0096] (Judgment Department)

[0097] The determination unit 405 uses the corrected information on the time-varying predicted storage capacity to determine whether an overflow has occurred in the storage, similar to the case in Embodiment 1. If an overflow occurs, the determination unit 405 notifies the storage capacity calculation unit 404 of the overflow, and the storage capacity calculation unit 404 calculates the total communication speed if no overflow occurs. If no overflow occurs, the processing information (period, frequency, resolution, or compression ratio) of various sensors in the sensor information table is sent to the data processing unit 406.

[0098] (Data Processing Department, Storage Control Department)

[0099] Similar to Embodiment 1, the data processing unit 406 processes the sensor data based on the processing information received from the determination unit 405, and the storage control unit 407 stores the processed sensor data in the storage of the memory 202.

[0100] <Action>

[0101] Next, refer to Figure 10 The operation of the data transmission device 500 will be explained. In Embodiment 2, as... Figure 7 The processing performed by the subroutine in step A3 differs from that in embodiment 1. In embodiment 2, instead of embodiment 1, Figure 8 The flowchart is used to perform Figure 10 The flowchart processing. Below, we will refer to... Figure 10 Explanation as Figure 7 The processing is performed by the subroutine in step A3.

[0102] In step C1, the storage calculation unit 404 obtains from the server 102 via the communication unit 400 the amount of data that can be sent from the vehicle to the server 102 along the traveled path (i.e., the measured value of the mobile data communication speed), time information, and location information.

[0103] In step C2, the storage calculation unit 404 obtains the measured vehicle speed, time information and location information on the route traveled from the vehicle speed notification unit 403.

[0104] In step C3, similar to step B2, the storage quantity calculation unit 404 calculates the time shift of the predicted storage quantity.

[0105] In step C4, the storage capacity calculation unit 404 uses the values ​​obtained in steps C1 and C2 and the time shift of the predicted storage capacity calculated in step C3 to calculate the sensor data communication speed according to equation (2). Then, the sensor information table is rewritten using the calculation results.

[0106] In step C5, the storage capacity calculation unit 404 uses the corrected sensor data communication speed to recalculate the time shift of the predicted storage capacity. The storage capacity calculation unit 404 then sends the corrected time shift of the predicted storage capacity to the determination unit 405.

[0107] In step C6, the determination unit 405 uses the time shift of the corrected predicted memory storage amount to determine whether an overflow has occurred.

[0108] If it is determined that no overflow will occur, the process branches off in step C7 and proceeds to step C9. In step C9, the determination unit 405 outputs the value of the sensor information table to the data processing unit 406.

[0109] If an overflow is detected, the process branches off in step C7 and proceeds to step C8. In step C8, the determination unit 405 notifies the storage calculation unit 404 of the overflow, and the storage calculation unit 404 calculates the sensor data communication speed if an overflow does not occur.

[0110] According to the data transmission device 500 described above, the communication unit 400 is configured to acquire from the server 102 a measured value (the value of the fourth data communication speed) of the mobile data communication speed related to the sensor data that can actually be transmitted from the communication unit 400 to the server 102. Furthermore, the vehicle speed notification unit 403 is configured to notify the vehicle of its actual speed while traveling on the already traveled portion of the travel path. Additionally, the storage capacity calculation unit 404 is configured to correct the predicted mobile data communication speed value (the value of the second data communication speed) using the measured value of the mobile data communication speed (the fourth data communication speed), and correct the predicted vehicle speed using the actual vehicle speed, thereby correcting the time shift of the predicted storage capacity. Therefore, the accuracy of the time shift of the predicted storage capacity can be improved. By improving the prediction accuracy, the occurrence of memory overflow can be appropriately suppressed.

[0111] <Postscript>

[0112] The following is a summary of several aspects of the implementation methods described above.

[0113] (Postscript 1)

[0114] The data transmission apparatus (100, 500) in Appendix 1 includes: a data acquisition unit (301) that acquires sensor data detected by the sensor (101) at a first data communication speed; a communication unit (300, 400) that transmits the acquired sensor data to a server at a second data communication speed; a storage capacity calculation unit (304, 404) that uses the first data communication speed and the second data communication speed to calculate the time shift of a predicted storage capacity of the acquired sensor data to be stored in a memory; and a determination unit (305, 405) that determines whether the sensor data stored in the memory has overflowed based on the time shift of the predicted storage capacity.

[0115] (Postscript 2)

[0116] The data transmission device in Appendix 2 is the same as the data transmission device in Appendix 1, and further includes a data processing unit (306, 406). The data processing unit (306, 406) processes the sensor data according to the processing information. If it is determined that the sensor data stored in the memory is overflowing, the storage capacity calculation unit is configured to calculate third data communication data that does not cause overflow to update the processing information. The data processing unit is configured to process the acquired sensor data according to the updated processing information, and the communication unit is configured to send the processed sensor data to the external server.

[0117] (Note 3)

[0118] The data transmission device in Appendix 3 is the data transmission device in Appendix 1 or 2. The sensor includes multiple sensors. The data acquisition unit is configured to acquire sensor data from each sensor. The data processing unit is configured to process the sensor data from each sensor based on a priority assigned to each sensor.

[0119] (Note 4)

[0120] The data transmission device in Appendix 4 is the data transmission device of any one of Appendices 1 to 3, and further includes: a driving route notification unit (302) that notifies the vehicle of a predetermined driving route; and a vehicle speed notification unit (303, 403) that predicts the vehicle speed in the notified driving route and notifies it, wherein the storage capacity calculation unit is configured to calculate the time shift of the predicted storage capacity using the predicted vehicle speed in addition to the first data communication speed and the second data communication speed.

[0121] (Note 5)

[0122] The data transmission device in Appendix 5 is the same as the data transmission device in Appendix 4. The communication unit is configured to obtain a fourth data communication speed related to the sensor data that can actually be sent from the communication unit to the external server from the external server. The vehicle speed notification unit is configured to notify the vehicle of its actual speed when traveling on the already traveled portion of the driving path. The storage capacity calculation unit corrects the second data communication speed using the fourth data communication speed, corrects the predicted vehicle speed using the actual vehicle speed, and corrects the time shift of the predicted storage capacity.

[0123] (Note 6)

[0124] The data transmission method in Appendix 6 includes: acquiring sensor data detected by a sensor at a first data communication speed; sending the acquired sensor data to an external server at a second data communication speed; calculating the time shift of a predicted storage amount of the acquired sensor data to be stored in a memory using the first data communication speed and the second data communication speed; and determining whether the sensor data stored in the memory has overflowed based on the time shift of the predicted storage amount.

[0125] In addition, the implementation methods can be combined, or the implementation methods can be appropriately modified or omitted.

[0126] Industrial practicality

[0127] According to the data transmission apparatus disclosed herein, sensor data can also be collected from areas where wireless communication line speeds are low. Therefore, it is possible to utilize it as an in-vehicle device mounted on a vehicle.

[0128] Label Explanation

[0129] 10 Data Transmission System

[0130] 100 data transmission device

[0131] 101 (101-1~101-n) sensor

[0132] Server 102

[0133] Vehicle 103

[0134] 200 External Network I / F

[0135] 201 processor

[0136] 202 memory

[0137] 202a ROM

[0138] 202b RAM

[0139] 203 Internal Network I / F

[0140] 300 Communications Department

[0141] 301 Data Acquisition Department

[0142] 302 Driving Route Notification Department

[0143] 303 Speed ​​Notification Department

[0144] 304 Storage Calculation Department

[0145] 305 Judgment Department

[0146] 306 Data Processing Department

[0147] 307 Memory Control Unit

[0148] 400 Communications Department

[0149] 403 Speed ​​Notification Department

[0150] 404 Storage Calculation Department

[0151] 405 Judgment Department

[0152] 406 Data Processing Department

[0153] 407 Storage Control Unit

[0154] 500 data transmission device.

Claims

1. A data transmission device, characterized in that, include: The data acquisition unit acquires sensor data detected by the sensor via a first data communication speed; The communication unit transmits the acquired sensor data to an external server via the second data communication speed. A storage capacity calculation unit uses the first data communication speed and the second data communication speed to calculate the time shift of the predicted storage capacity of the acquired sensor data to be stored in the memory; as well as The determination unit determines, based on the time progression of the predicted storage amount, whether the sensor data stored in the memory has overflowed.

2. The data transmission device as described in claim 1, characterized in that, It also includes a data processing unit that processes the sensor data based on the processing information. If it is determined that the sensor data stored in the memory has overflowed, the storage capacity calculation unit is configured to calculate a third data communication speed that does not cause overflow to update the processing information. The data processing unit is configured to process the acquired sensor data based on the updated processing information. The communication unit is configured to send the processed sensor data to the external server.

3. The data transmission device as described in claim 2, characterized in that, The sensor includes multiple sensors. The data acquisition unit is configured to acquire sensor data from each sensor. The data processing unit is configured to process sensor data from each sensor based on a priority assigned to each sensor.

4. The data transmission apparatus according to any one of claims 1 to 3, characterized in that, Also includes: The route notification unit notifies the vehicle of the predetermined route to travel. as well as The vehicle speed notification unit predicts the vehicle's speed along the notified travel path and sends a notification. The storage capacity calculation unit is configured to use the predicted vehicle speed, in addition to the first data communication speed and the second data communication speed, to calculate the time shift of the predicted storage capacity.

5. The data transmission device as described in claim 4, characterized in that, The communication unit is configured to obtain a fourth data communication speed related to the sensor data that can actually be sent from the communication unit to the external server. The vehicle speed notification unit is configured to notify the vehicle of its actual speed while traveling on the already traveled portion of the driving path. The storage capacity calculation unit corrects the second data communication speed using the fourth data communication speed, corrects the predicted vehicle speed using the actual vehicle speed, and corrects the time shift of the predicted storage capacity.

6. A data transmission method, characterized in that, include: Sensor data detected by the sensor is acquired through the first data communication speed; The acquired sensor data is sent to an external server via the second data communication speed; Using the first data communication speed and the second data communication speed, calculate the time shift of the predicted storage amount of the acquired sensor data to be stored in the memory; as well as Based on the time progression of the predicted storage amount, it is determined whether the sensor data stored in the memory has overflowed.

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