Data communication equipment

Abstract

To generate probe data suitable for data analysis or the like.SOLUTION: A data communication device 10 comprises: an acquisition section 111 for acquiring sensor data including a physical amount related to a behavior of a target at a first cycle from a camera 12 and a radar 13; a generation section 112 for generating probe data based on the sensor data acquired by the acquisition section 111; and a transmission section 113 for transmitting the probe data generated by the generation section 112 at a second cycle longer than the first cycle. The generation section 112 calculates a differential value of the physical amount included in each one of a plurality of elements of sensor data acquired by the acquisition section 111 at the first cycle during the second cycle, and causes behavior information indicating the behavior of the target generated based on the calculated differential value to be stored in the probe data.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present invention relates to a data communication device that transmits probe data. [Background technology]

[0002] Conventionally, there has been known a device that accumulates sensor data, such as position information, received from a moving object such as a probe car in a storage means (see, for example, Patent Document 1). In the device described in Patent Document 1, in order to reduce storage capacity, sensor data to be stored is extracted from the sensor data received from the moving object based on a sampling period determined according to the speed of the moving object. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent No. 2011-192198 Summary of the Invention [Problem to be solved by the invention]

[0004] However, if the sampling period is changed as in the device described in Patent Document 1, there is a risk that information required for data analysis and the like cannot be obtained with high accuracy. [Means for solving the problem]

[0005] A data communication device 10 according to one aspect of the present invention includes an on-board sensor that detects targets around a vehicle, and an acquisition unit that acquires sensor data including physical quantities related to behavior of the targets from the on-board sensor at a first period. A difference value of a physical quantity included in each of the plurality of sensor data acquired in the first period by the acquisition unit is calculated during a second period longer than the first period, and behavior information indicating a behavior of the target generated based on the calculated difference value is stored. A generation unit that generates probe data, and the probe data generated by the generation unit No. A transmitter that transmits in two cycles; a priority calculation unit that calculates a priority for each of the plurality of targets based on position information included in the sensor data corresponding to each of the plurality of targets when the plurality of targets are detected by an on-vehicle sensor; The generating unit includes: A predetermined number of targets are extracted from the plurality of targets according to the priorities calculated by the priority calculation unit, behavior information indicating the behavior of each of the predetermined number of targets during the second period is generated, and the behavior information corresponding to each of the predetermined number of targets is stored in the probe data. When the relative position of the target in the vehicle width direction with respect to the vehicle, which is indicated by the position information, is equal to or greater than a predetermined value, the priority calculation unit calculates the priority so that the priority is gradually lowered as the relative position becomes larger. do. Effect of the Invention

[0006] According to the present invention, probe data suitable for data analysis and the like is generated. [Brief description of the drawings]

[0007] [Figure 1] FIG. 1 is a diagram showing an example of the configuration of a system including an information processing apparatus according to an embodiment of the present invention. [Diagram 2] 1 is a block diagram showing a configuration of a main part of a data communication device according to an embodiment of the present invention. [Diagram 3] FIG. 4 is a diagram showing an example of a data structure of probe data. [Figure 4] FIG. 4 is a diagram showing an example of sensor target probe information. [Diagram 5] FIG. 4 is a diagram showing an example of PF target probe information. [Figure 6] 3 is a flowchart showing an example of processing executed by a calculation unit in FIG. 2. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0008] Hereinafter, an embodiment of the present invention will be described with reference to Figs. 1 to 6. Fig. 1 is a diagram showing an example of the configuration of a system including an on-vehicle device (hereinafter referred to as a data communication device) according to this embodiment. As shown in Fig. 1, the system 1 includes a data communication device 10 and a server device 30. The data communication device 10 is mounted on a vehicle 20. The vehicle 20 includes a plurality of vehicles 20-1, 20-2, . . . , 20-n. The vehicle 20 may be a manually driven vehicle or an automatically driven vehicle. The vehicle 20 may include vehicles of different models and grades. The data communication device 10 is configured to be able to communicate with the server device 30 via a communication network 2. The data communication device 10 transmits probe data generated based on information (hereinafter referred to as sensor data) detected by various sensors mounted on the vehicle 20 to the server device 30 via the communication network 2. The server device 30 collects the probe data transmitted from the vehicle 20 and performs data analysis. The server device 30 uses the results of the data analysis to recognize, for example, traffic information indicating the congestion state of the road on which the vehicle 20 is traveling, and to recognize the external environment of the vehicle 20. Furthermore, the server device 30 provides (distributes) the recognition results to the user.

[0009] The communication network 2 includes not only public wireless communication networks such as the Internet and mobile phone networks, but also closed communication networks established for each designated management area, such as wireless LAN, Wi-Fi (registered trademark), Bluetooth (registered trademark), etc.

[0010] 2 is a block diagram showing the configuration of the main parts of the data communication device 10 according to this embodiment. The data communication device 10 includes an electronic control unit (ECU) 11, a camera 12, a radar 13, and an MPU (Map Positioning Unit) 14.

[0011] The camera 12 is a monocular camera or a stereo camera having an imaging element (image sensor) such as a CCD or a CMOS. The camera 12 is attached, for example, at a predetermined position in the front of the vehicle 20, and continuously captures images of the space in front of the vehicle 20 to obtain images of objects. The objects include stationary objects and moving objects around the vehicle 20. The stationary objects include obstacles and the like. The moving objects include other vehicles, more specifically, vehicles traveling in front of the vehicle 20 (hereinafter referred to as a forward vehicle) and vehicles traveling in an oncoming lane (hereinafter referred to as an oncoming vehicle). The moving objects include pedestrians. The camera 12 outputs the captured images to the ECU 11 as sensor data. The radar 13 is mounted on the vehicle 20, and detects the objects by irradiating electromagnetic waves and detecting reflected waves. The radar 13 outputs a detection value (sensor data) to the ECU 11.

[0012] The MPU 14 is configured to be able to communicate with external devices including a server device 30 and the like via the communication network 2. When the MPU 14 receives the latest map information transmitted from a map distribution server (not shown), it updates the map information stored in a storage device (not shown) with the received latest map information.

[0013] 2, the ECU 11 includes a computer having a calculation unit 110 such as a CPU, a storage unit 120 such as a ROM and a RAM, and other peripheral circuits (not shown) such as an I / O interface. The calculation unit 110 functions as an acquisition unit 111, a generation unit 112, and a transmission unit 113 by executing a program previously stored in the storage unit 120. If the MPU 14 has a storage unit (not shown) such as a ROM and a RAM, the map information may be stored in the storage unit of the MPU 14.

[0014] The acquisition unit 111 acquires the sensor data output from each of the camera 12 and the radar 13 at a predetermined sampling period SC. The sensor data includes physical quantities related to the behavior of an object (hereinafter also referred to as a target). The physical quantities related to the behavior include the relative position of the target with respect to the vehicle 20, more specifically, the longitudinal position (relative position in the traveling direction of the vehicle 20) and the lateral position (relative position in the width direction of the vehicle 20).

[0015] The generating unit 112 generates probe data based on the sensor data of the camera 12 and the radar 13 acquired by the acquiring unit 111. FIG. 3 is a diagram showing an example of a data structure of the probe data. As shown in FIG. 3, the probe data includes target information, M pieces of PF (Perception Fusion) target probe information, and N pieces of sensor target probe information. The target information includes the number of targets detected by the camera 12 and the radar 13, etc. The PF target probe information is information generated by fusing the sensor data of the camera 12 and the radar 13. The PF target probe information will be described later.

[0016] The sensor target probe information is information generated based on sensor data from either the camera 12 or the radar 13. The sensor target probe information includes information (sensor target status information) indicating which sensor data from the camera 12 or the radar 13 the probe information is generated based on, and physical quantities of the target obtained based on the sensor data (longitudinal position, lateral position, and longitudinal speed). The longitudinal speed of the target is the absolute speed of the target relative to the vehicle 20. The generating unit 112 quantizes each physical quantity of the target according to a resolution corresponding to each physical quantity, and stores each quantized physical quantity in the sensor target probe information. FIG. 4 is a diagram showing an example of the sensor target probe information #1 to #N. The sensor target probe information is generated based on the latest sensor data from the camera 12 and the radar 13 acquired by the acquiring unit 111 for each transmission period TC described later.

[0017] The transmission unit 113 transmits the probe data generated by the generation unit 112 to the server device 30 at a predetermined transmission period TC via the MPU 14 communicably connected to the server device 30. The transmission period TC is a period longer than the sampling period SC.

[0018] Here, the PF target probe information will be described. For the sake of simplicity, a case where only one target exists around the vehicle 20 will be described as an example. The generation unit 112 judges whether or not a target has been detected by the camera 12 and the radar 13 based on the sensor data of the camera 12 and the radar 13, and stores information indicating the judgment result (hereinafter referred to as a lost flag) in the PF target probe information. When a target has been detected by the camera 12 and the radar 13, the generation unit 112 judges whether or not the target is a newly detected target (not detected in the previous sampling), and stores information indicating the judgment result (hereinafter referred to as a new flag) in the PF target probe information. When a target has been detected by the camera 12 and the radar 13, the generation unit 112 recognizes the type of the target from the sensor data of the camera 12 and the radar 13. The type of the target is a stationary object, a moving object, a pedestrian, an oncoming vehicle, etc. The generation unit 112 may further recognize the classification of moving objects and oncoming vehicles, such as a motorbike, a car, a truck, a bicycle, and the like.

[0019] When a target is detected by the camera 12 and the radar 13, the generation unit 112 reads out the vertical position, horizontal position, and vertical speed of the target from the sensor data of the camera 12 and the radar 13 acquired by the acquisition unit 111. At this time, the generation unit 112 reads out each physical quantity (vertical position, horizontal position, and vertical speed) from the sensor data of the camera 12 or the radar 13, whichever has a higher detection accuracy for the physical quantity. For example, if the camera 12 has a higher detection accuracy for the horizontal position than the radar 13, the generation unit 112 reads out the horizontal position of the target from the sensor data of the camera 12. Also, for example, if the radar 13 has a higher detection accuracy for the vertical position than the camera 12, the generation unit 112 reads out the vertical position of the target from the sensor data of the radar 13.

[0020] The generating unit 112 generates physical quantity data including each physical quantity read from the sensor data as described above, information indicating the type of the sensor (camera 12 or radar 13) that detected each physical quantity and the type (classification) of the target recognized based on the sensor data (hereinafter referred to as PF target status information), and information indicating whether the PF target status information has been updated (hereinafter referred to as status update flag or simply update flag) every time the acquiring unit 111 acquires the sensor data of the camera 12 and the radar 13 at the sampling period SC. The generating unit 112 stores the generated physical quantity data in the PF target probe information. FIG. 5 is a diagram showing an example of the PF target probe information #1 to #M. The number of physical quantity data stored in a single PF target probe information is determined according to the length of the transmission period TC. In the example shown in FIG. 5, five physical quantity data are stored in order in each of the PF target probe information #1 to #M. That is, FIG. 5 shows an example when the sampling period SC is one-fifth of the transmission period TC. 5 represent the physical quantity data stored in the PF target probe information #1. In the following, among the physical quantity data #1 to #5, the physical quantity data #1 is the first data obtained, and the physical quantity data #5 is the last data obtained.

[0021] The generating unit 112 generates the physical quantity data to be stored in the PF target probe information as follows. First, the generating unit 112 compresses and quantizes the physical quantities (longitudinal position, lateral position, and longitudinal speed) obtained from the sensor data. Then, the generating unit 112 stores the compressed and quantized physical quantities in the physical quantity data. Here, the compression and quantization of the physical quantities will be described. Hereinafter, the physical quantities stored in the physical quantity data #1 to #5 will be referred to as physical quantities #1 to #5. In addition, the PF target status information stored in the physical quantity data #1 to #5 will be referred to as PF target status information #1 to #5. In addition, the update flags stored in the physical quantity data #1 to #5 will be referred to as update flags #1 to #5. In addition, the sensor data used to generate the physical quantity data #1 to #5 will be referred to as sensor data #1 to #5.

[0022] First, the generating unit 112 quantizes the physical quantity #1 according to the resolution. For example, when the resolution of the horizontal position is 0.5 [m] and the horizontal position of the physical quantity #1 is 100.6 [m], the horizontal position after quantization is 100.6 [m] / 0.5 [m]=201 (rounded to the nearest whole number). Next, the generating unit 112 compresses the physical quantities #2 to #5 and quantizes them according to the resolution. Specifically, the generating unit 112 quantizes the difference value obtained by subtracting the physical quantity #2 from the physical quantity #1 according to the resolution. For example, when the horizontal position of the physical quantity #2 is 90.3 [m], the horizontal position of the physical quantity #2 after quantization is 10.3 (=100.6-90.3) [m] / 0.5 [m]=20 (rounded to the nearest whole number). Similarly, the generation unit 112 quantizes the difference value obtained by subtracting the physical quantities #2 and #3 from the physical quantity #1 according to the resolution. Similarly, the generation unit 112 quantizes the difference value obtained by subtracting the physical quantities #2 to #4 from the physical quantity #1 according to the resolution. Similarly, the generation unit 112 quantizes the difference value obtained by subtracting the physical quantities #2 to #5 from the physical quantity #1 according to the resolution. The generation unit 112 stores the quantized physical quantities #1 to #5 obtained in this way in the physical quantity data #1 to #5. The quantized physical quantities #1 to #5 indicate the behavior of the target during the transmission period TC.

[0023] Moreover, the generating unit 112 generates PF target status information #1-#5 and update flags #1-#5 to be stored in the physical quantity data #1-#5. First, the generating unit 112 recognizes the type of the target based on each sensor data acquired at the sampling period SC during the transmission period TC, and generates PF target status information #1-#5 including the recognition result of each target of each sensor data.

[0024] When storing PF target status information #N and update flag #N in physical quantity data #N (N=2, 3, . . . , 5), the generating unit 112 first determines whether or not the PF target status information #N is different from the PF target status information #N-1. When the PF target status information #N and the PF target status information #N-1 are different, the generating unit 112 stores the update flag #N set to 1 in the physical quantity data #N. On the other hand, when the PF target status information #N and the PF target status information #N-1 are the same, the generating unit 112 stores the update flag #N set to 0 in the physical quantity data #N. Note that the update flag #1 is set to 0.

[0025] Next, the generating unit 112 stores the PF target status information #N in the physical quantity data #N when the update flag #N is 1. On the other hand, when the update flag #N is 0, the generating unit 112 does not store the PF target status information #N in the physical quantity data #N. Note that the PF target status information #1 is stored in the physical quantity data #1 regardless of the value of the update flag #1.

[0026] In this way, by compressing the physical quantity data #1 to #5 stored in the PF target probe information, it is possible to include information required for data analysis, etc. in the PF target probe information without unnecessarily increasing the data capacity of the PF target probe information. Note that the free space in the probe data obtained by reducing the data capacity of the PF target probe information may be used as a storage area for the sensor target probe information.

[0027] When there are multiple targets around the vehicle 20 and the multiple targets are detected by the camera 12 and the radar 13, the sensor data acquired by the acquisition unit 111 includes physical quantities corresponding to the multiple targets. In this case, the generation unit 112 reads out the physical quantities corresponding to the multiple targets from the sensor data. Then, the generation unit 112 generates PF target probe information and sensor target probe information corresponding to each of the multiple targets and stores them in the probe data. Note that when the multiple targets detected by the camera 12 and the radar 13 include a target for which PF target probe information and sensor target probe information have already been generated, the physical quantity corresponding to the target is stored in the existing PF target probe information and sensor target probe information corresponding to the target.

[0028] When more than M targets are detected by the camera 12 and the radar 13, the generating unit 112 calculates priorities (hereinafter referred to as PF target priorities) for determining targets to be stored in the PF target probe information. The generating unit 112 extracts M targets with high PF target priorities from the multiple targets according to the PF target priorities, and generates PF target probe information corresponding to each of the extracted M targets. The PF target priorities are calculated based on the position information (lateral and vertical positions) of the targets. More specifically, the PF target priorities are calculated so that the smaller the values ​​of the lateral and vertical positions are, the higher the PF target priorities are calculated. When calculating the PF target priorities, the generating unit 112 may multiply the lateral position by a coefficient that gradually lowers the PF target priority as the lateral position increases when the value of the lateral position of the target is equal to or greater than a predetermined value. In addition, the generation unit 112 may calculate the reliability of detection of each of multiple targets based on the sensor data of the camera 12 and the radar 13, and multiply the PF target priority by a coefficient such that the PF target priority becomes higher as the reliability increases.

[0029] Furthermore, when more than N targets are detected by the camera 12 and the radar 13, the generation unit 112 calculates priorities (hereinafter referred to as sensor target priorities) for determining targets to be stored in the sensor target probe information. The generation unit 112 extracts N targets with high sensor target priorities from the multiple targets according to the sensor target priorities, and generates sensor target probe information corresponding to each of the extracted N targets. The sensor target priorities are calculated based on the position information (lateral and vertical positions) of the targets, similar to the PF target priorities. When calculating the sensor target priorities, the generation unit 112 increases the sensor target priorities in stages as the lateral position increases when the lateral position of the target is equal to or greater than a predetermined value, similar to the PF target priorities. Low In addition, for example, when the sensor data of the camera 12 and the radar 13 includes information indicating the probability of the presence of a target, the sensor target priority may be multiplied by a coefficient such that the higher the probability of the presence, the higher the sensor target priority.

[0030] FIG. 6 is a flowchart showing an example of processing executed by the calculation unit 110 (CPU) of the data communication device 10 according to a predetermined program. The processing shown in this flowchart is repeated at a sampling period SC. First, at step S11, sensor data output from each of the camera 12 and the radar 13 is acquired. At step S12, the sensor data acquired at step S11 is stored in a predetermined area (such as a ring buffer) of the storage unit 120. At step S13, it is determined whether or not it is time to transmit probe data based on the transmission period TC. If the result at step S13 is negative, the processing is terminated. If the result at step S13 is positive, at step S14, physical quantity data (the above physical quantity data #1 to #5) is generated based on each sensor data stored in the predetermined area, i.e., each sensor data acquired at the sampling period SC during the transmission period TC (the above sensor data #1 to #5). At step S15, PF target probe information is generated that stores the physical quantity data generated at step S15. At step S16, sensor target probe information is generated based on the sensor data last stored in the predetermined area, i.e., the latest sensor data. In step S17, output data (probe data) is generated that stores the PF target probe information generated in step S15 and the sensor target probe information generated in step S16. In step S18, the output data is transmitted via the MPU 14.

[0031] According to the embodiment of the present invention, the following advantageous effects can be obtained. (1) The data communication device 10 includes an on-board sensor (camera 12, radar 13) that detects targets around the vehicle 20, an acquisition unit 111 that acquires sensor data including physical quantities related to the behavior of the target from the on-board sensor in a first period (sampling period SC), a generation unit 112 that generates probe data based on the sensor data acquired by the acquisition unit 111, and a transmission unit 113 that transmits the probe data generated by the generation unit 112 in a second period (transmission period TC) longer than the first period. The generation unit 112 calculates a difference value of the physical quantities included in each of the multiple sensor data acquired in the first period by the acquisition unit 111 during the second period, and stores behavior information (compressed and quantized physical quantities #1 to #5) indicating the behavior of the target generated based on the calculated difference value in the probe data. This allows the sensor data acquired in the sampling period SC to be efficiently stored in the probe data. As a result, it is possible to output probe data that is more suitable for data analysis and the like. Furthermore, since probe data suitable for data analysis and the like can be transmitted to the server device 30 without shortening the transmission period to match the sampling period, there is no unnecessary increase in the communication load between the server device 30. Furthermore, by outputting efficiently compressed probe data, an increase in the storage capacity of the server device 30 can be suppressed.

[0032] (2) When the plurality of sensor data acquired in the first period by the acquisition unit 111 during the second period include the first sensor data (sensor data #1), the second sensor data (sensor data #2) acquired after the first sensor data, and the third sensor data (sensor data #3) acquired after the second sensor data, the generation unit 112 generates behavior information indicating the behavior of the target during the second period based on the physical quantity included in the first sensor data, a difference value obtained by subtracting the physical quantity included in the second sensor data from the physical quantity included in the first sensor data, and a difference value obtained by subtracting the physical quantities included in the second and third sensor data from the physical quantity included in the first sensor data, and stores the behavior information in the probe data. This allows efficient data compression to be realized.

[0033] (3) The generation unit 112 calculates the priority of each target based on the position information of the target included in the sensor data acquired by the acquisition unit 111. When multiple targets are detected by the on-board sensor, the generation unit 112 calculates the priority of each of the multiple targets based on the sensor data corresponding to each of the multiple targets. The generation unit 112 extracts a predetermined number of targets from the multiple targets according to the calculated priority, generates behavior information indicating the behavior of each of the predetermined number of targets during the second period, and stores the behavior information corresponding to each of the predetermined number of targets in the probe data. As a result, information of targets with high priority is preferentially stored in the probe data, so that probe data more suitable for data analysis, etc. can be output.

[0034] (4) The generating unit 112 generates, for each first period, status information indicating the type of the target and the identification information of the vehicle-mounted sensor that detected the target, and an update flag indicating whether the status information has changed, and further stores the status information and the update flag in the probe data. Furthermore, when the update flag indicates that the status information has not changed, the generating unit 112 does not store the status information in the probe data. This makes it possible to reduce the data size of the probe data.

[0035] The above embodiment can be modified in various ways. Modifications will be described below.

[0036] In the above embodiment, when multiple targets are detected by an on-board sensor, the generation unit 112 as a priority calculation unit calculates priorities for each of the multiple targets based on the position information of the targets included in the sensor data corresponding to each of the multiple targets. The generation unit 112 also extracts a predetermined number of targets from the multiple targets according to the calculated priorities, generates behavior information indicating the behavior of each of the predetermined number of targets during the second period, and stores the behavior information corresponding to each of the predetermined number of targets in the probe data. However, the generation unit may generate behavior information indicating the behavior of each of the multiple targets during the second period, and store the behavior information corresponding to each of the multiple targets in the probe data in the order according to the priorities calculated by the priority calculation unit. As a result, information on targets with high priorities is preferentially stored in the probe data, so that probe data more suitable for data analysis, etc. can be output.

[0037] In the above embodiment, the transmission unit 113 transmits the probe data generated by the generation unit 112 via the MPU 14 communicatively connected to the server device 30. However, if the data communication device 10 includes a communication unit or the like, the probe data generated by the generation unit 112 may be transmitted via the communication unit.

[0038] In the above embodiment, the acquisition unit 111 acquires sensor data output from the camera 12 and the radar 13 as on-board sensors. However, if the vehicle 20 is equipped with a LIDAR, the acquisition unit may acquire the detection value (sensor data) of the LIDAR. Furthermore, in the above embodiment, the data communication device 10 mounted on the vehicle 20 is shown as an example, but the data communication device may be mounted on a moving body other than a vehicle.

[0039] The above description is merely an example, and the present invention is not limited to the above-mentioned embodiment and modifications, as long as the features of the present invention are not impaired. One or more of the above-mentioned embodiment and modifications can be arbitrarily combined, and modifications can also be combined with each other. [Explanation of symbols]

[0040] 10 data communication device, 11 ECU, 12 camera, 13 radar, 14 MPU, 20, 20-1 to 20-n vehicles, 30 server device, 110 calculation unit, 111 acquisition unit, 112 generation unit, 113 transmission unit, 120 storage unit

Claims

1. An on-board sensor that detects targets around the vehicle; an acquisition unit that acquires sensor data including a physical quantity related to a behavior of the target from the on-board sensor at a first period; a generation unit that calculates difference values ​​of the physical quantities included in each of the plurality of pieces of sensor data acquired by the acquisition unit in the first period during a second period that is longer than the first period, and generates probe data by storing behavior information that indicates a behavior of the target and is generated based on the calculated difference values; a transmission unit that transmits the probe data generated by the generation unit at the second period; a priority calculation unit that calculates a priority for each of the plurality of targets based on position information included in the sensor data corresponding to each of the plurality of targets when the plurality of targets are detected by the on-board sensor, the generation unit extracts a predetermined number of the targets from the plurality of targets in accordance with the priorities calculated by the priority calculation unit, generates the behavior information indicating behaviors of each of the predetermined number of the targets during the second period, and stores the behavior information corresponding to each of the predetermined number of the targets in the probe data; a priority calculation unit that calculates the priority so that the priority gradually decreases as the relative position of the target with respect to the vehicle, as indicated by the position information, increases when the relative position is equal to or greater than a predetermined value.

2. An on-board sensor for detecting objects around a vehicle; an acquisition unit that acquires sensor data including a physical quantity related to a behavior of the target from the on-board sensor at a first period; a generation unit that calculates difference values ​​of the physical quantities included in each of the plurality of pieces of sensor data acquired by the acquisition unit in the first period during a second period that is longer than the first period, and generates probe data by storing behavior information that indicates a behavior of the target and is generated based on the calculated difference values; a transmission unit that transmits the probe data generated by the generation unit at the second period, a priority calculation unit that calculates a priority for each of the plurality of targets based on position information included in the sensor data corresponding to each of the plurality of targets when the plurality of targets are detected by the on-board sensor; the generation unit generates the behavior information indicating behaviors of each of the plurality of targets during the second period, and stores the behavior information corresponding to each of the plurality of targets in the probe data in an order according to the priority calculated by the priority calculation unit; a priority calculation unit that calculates the priority so that the priority gradually decreases as the relative position of the target with respect to the vehicle, as indicated by the position information, increases when the relative position is equal to or greater than a predetermined value.

3. In the data communication device according to claim 1 or 2, the generation unit, when the plurality of sensor data acquired in the first cycle by the acquisition unit during the second cycle include first sensor data, second sensor data acquired after the first sensor data, and third sensor data acquired after the second sensor data, generates the behavior information indicating a behavior of the target during the second cycle based on the physical quantity included in the first sensor data, the difference value obtained by subtracting the physical quantity included in the second sensor data from the physical quantity included in the first sensor data, and the difference value obtained by subtracting the physical quantities included in the second and third sensor data from the physical quantity included in the first sensor data, and stores the behavior information in the probe data.

4. A data communication device according to claim 1 or 2, the generation unit generates, for each of the first periods, status information indicating a type of the target and identification information of the on-board sensor that detected the target, and an update flag indicating whether or not there has been a change in the status information, and further stores the status information and the update flag in the probe data; The data communication device is further characterized in that the generation unit does not store the status information in the probe data when the update flag indicates that there is no change in the status information.

Images