JP2017004177A - Sensor data collection system and method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To collect sensor data necessary for service provision even with a transfer capacity limit in collecting sensor data.SOLUTION: A sensor data collection system comprises: an on-vehicle machine for transmitting an identifier of a first roadside machine, responding to specification of a section and transmitting sensor data of the section; and a second roadside machine for responding to the reception of the identifier of the first roadside machine, specifying a section on a route from the first roadside machine and receiving the sensor data from the on-vehicle machine.SELECTED DRAWING: Figure 4

Description

  The present invention relates to a system and method for collecting data acquired by a sensor using communication. In particular, the present invention relates to a sensor data collection system and method for collecting sensor data acquired by a sensor mounted on a mobile body from a mobile body to an aggregator as a fixed station such as a roadside device or an access point using wireless communication.

  As a technique for collecting data acquired by a sensor mounted on a moving body using communication, there are Patent Document 1 and Patent Document 2. In Patent Document 1, the in-vehicle device receives service information from the server device, extracts and compresses data necessary for the service from the data of the in-vehicle device, and transmits the data to the server device. The server device transmits data for each service from the received data. Is extracted, decrypted, and sent to the service server. In Patent Document 2, each vehicle determines a vehicle group and a parent vehicle, and data of all vehicles is determined based on information that the parent vehicle receives from the collection center and defines restrictions on a set of data to be raised to the collection center. It is processed into vehicle-only data and sent to the collection center.

JP2013-97530A Japanese Patent No. 4715659

  Sensor data utilization services such as collecting sensor data acquired by a mobile object, particularly a vehicle, etc., to a server, a center, etc. by communication and using it for traffic jam grasping etc. are increasing. Similarly, similar services have been attempted using sensors attached to or connected to mobile phones and mobile terminals that are carried by people and move. However, in communication used to collect sensor data in a server or the like, the amount of data that can be transferred, that is, the transfer capacity, is limited due to technical and cost requirements. Therefore, if the amount of sensor data acquired by the sensor is larger than the transfer capacity limit, all the sensor data cannot be aggregated in the server or the like, and there is a possibility that the sensor data necessary for service provision will be insufficient. .

  In response to this transfer capacity limitation, Patent Document 1 reduces the transfer amount by selecting or compressing sensor data. If sensor data is selected, the possibility of lack of sensor data cannot be resolved. In addition, the selection of sensor data is complicated because it is necessary to define the selection method as a service. In addition, since Patent Document 2 collects information in a representative vehicle of a vehicle group by inter-vehicle communication (communication between vehicles), the amount of transfer to the center is reduced by processing such as data averaging. . However, in the inter-vehicle communication between each vehicle and the representative vehicle before sending data to the center, the total capacity of sensor data to be transferred may exceed the transfer capacity limit depending on the number of vehicles constituting the vehicle group and the type of sensor. There is. That is, there is a possibility that a transfer capacity limitation problem occurs in inter-vehicle communication.

  Therefore, even if there is a transfer capacity limitation when collecting sensor data, it is necessary to collect sensor data necessary for providing the service.

  The disclosed sensor data collection system transmits an identifier of a first roadside device, and transmits the sensor data of the section in response to the designation of the section, and the first roadside machine from the onboard device In response to the reception of the identifier, a second roadside machine that designates a section on the route from the first roadside machine and receives sensor data from the in-vehicle machine is provided.

  According to the disclosed sensor data collection system, even if there is a transfer capacity limitation when collecting sensor data, it is possible to collect sensor data necessary for service provision.

It is a conceptual diagram explaining the transfer capacity restriction | limiting in sensor data collection. It is a schematic diagram of a sensor data collection system. It is an example of the path | route between roadside machines. It is a sequence diagram explaining the outline | summary of the process in a sensor data collection system. It is the whole structure of a sensor data collection system. This is a software configuration of the in-vehicle device. It is a software configuration of a roadside machine. It is an example of the sensor data which an onboard equipment hold | maintains. It is an example of the sensor data management table | surface of a roadside machine. It is a processing flowchart of a vehicle equipment and a roadside machine. It is an example of the section management table of a roadside machine. It is a flowchart of a whole route extraction process. It is a mimetic diagram explaining a roadside machine course, a partial course, and a whole course.

  The disclosed sensor data collection system collects a part of sensor data measured by each sensor in an aggregator based on the viewpoint that sensor data obtained by measuring environmental information that is geographically close to each other. The desired sensor data is restored by combining the sensor data. In accordance with the instruction of the aggregator, a sensor or a node such as a mobile body to which the sensor is connected transmits sensor data to the aggregator, and the aggregator combines sensor data from a plurality of sensors to restore desired sensor data. Is called aggregation. Each sensor transmits a part of the measured sensor data, so that the transfer amount of the sensor data falls within the limit of the transfer capacity, and the aggregator aggregates desired sensor data.

  The sensor data collection system aggregates sensor data acquired by a sensor mounted on a mobile body from the mobile body to an aggregator using wireless communication with limited transfer capacity. The moving body is a vehicle, a mobile phone or a mobile terminal that is carried by a person, and the aggregator is a fixed station such as a roadside device or an access point.

  As an example where the transfer capacity is limited and the application of this sensor data collection system is effective, the sensor data obtained by measuring the surrounding environment information with the sensors mounted on the vehicle is stored in the in-vehicle device, and around the road, traffic lights, etc. There is a collection of environmental information by a vehicle that collects sensor data in a roadside machine as an aggregator installed in the vehicle. Hereinafter, an example will be described for environmental information collection by a vehicle or a vehicle-mounted device as a moving body.

  FIG. 1 is a conceptual diagram illustrating transfer capacity limitation in sensor data collection. Vehicles (a) to (c) travel on the road, and while traveling, the surrounding environment information A to H is measured by an in-vehicle sensor and sensor data is accumulated in the in-vehicle device. The vehicle-mounted device transfers the sensor data to the roadside device when passing near the roadside devices X and Y installed around the road. However, since the roadside device cannot communicate unless the vehicle is within the communication range of the roadside device, the transferable data capacity is limited, and all the sensor data measured by each vehicle cannot be collected in the roadside device. That is, there is a transfer capacity limitation in the communication of sensor data between the vehicle and the roadside machine.

  Since the vehicles (a) to (c) are traveling on the same road, the sensor data of the respective vehicles measured at the same or close positions show almost the same value. Even if a part of the sensor data is selected by using this and the sensor data is transmitted within the transfer capacity, for example, the vehicle (a) determines which sensor data is transferred from the vehicle (a) to the roadside machine. ) Is not recognized. Therefore, as shown by the balloon on the right side of the figure, there is a possibility that data collected in the roadside device may be duplicated or may be lost due to a measurement error or a communication error. Therefore, selection of sensor data to be sent by the vehicles (a) to (c) needs to prevent duplication / deletion of data.

  The ambient environment information is information acquired from the periphery of the vehicle when the vehicle travels, and when acquired at geographically close locations, the information is similar to each other. Temperature data is a specific example of the surrounding environment information. As can be seen from the fact that the temperature is presented collectively for a range of areas as weather data, the measured temperature values are similar in neighboring areas. In addition to the temperature, the ambient environment information includes a value obtained by measuring a natural phenomenon such as topography, atmospheric pressure, humidity, and luminous intensity with a sensor. Another example of the surrounding environment information is an image taken by an in-vehicle photographing device. For example, a photograph taken in the north direction at a point on the road running north and south is similar to a photograph taken in the north direction 1 meter south from a certain point. In addition, for example, vibration data and speed data when traveling on a road are similar to data measured when a certain vehicle travels on a certain road and data measured by a vehicle traveling subsequent to the vehicle. Of course, although there is a difference depending on the characteristics of the sensor, the vehicle body, and the like, the data acquired at close points at close points tend to be similar to each other. In this embodiment, even if such completely consistent data is not obtained, the surrounding environment information in which similarity is observed in data close in space and time is targeted.

  The limitation of the transfer capacity will be described using specific numerical values, taking distance measurement data collection as an example. Ranging data is data obtained by measuring the distance to an object in a certain direction at a certain position.After collecting, it is finally converted into map information such as the width of the road and the position of the white line. It is used for grasping the current position of

  First, the amount of distance measurement data to be transferred is estimated. A laser sensor is used as the distance sensor. The laser sensor can measure the distance in units of 75 degrees and 75 degrees per second. The in-vehicle device is mounted on a vehicle that travels at a speed of 72 km / hr, acquires 3D position and time information with an accuracy of about 0.1 m using a satellite positioning system and gyro sensor, and 32 bytes of information along with the distance in one scan. If you get, the amount of distance measurement data is 21.6MB per km. Assuming that roadside equipment is installed at traffic lights, assuming that signals are installed at the intersections of paved roads, the average distance between traffic lights in urban areas is about 2 km from the number of traffic lights in Japan and the total length of paved roads. The amount of ranging data that the vehicle acquires from one roadside machine to the next roadside machine is 43.2MB.

  Subsequently, the transfer capacity is estimated. Communication between in-vehicle devices and roadside devices (road-to-vehicle communication) includes IEEE 802.15.4 (920 MHz band) for proximity communication, and IEEE 802.11p (5.8 MHz band) standardized for inter-vehicle communication and road-to-vehicle communication Is assumed. IEEE 802.15.4 radio wave reach is about 200m, transmission bandwidth is about 100kbps, so if the vehicle travels at 72km / h and passes in front of the roadside unit, the transfer capacity that can be transferred when passing is about 240KB at most It becomes. In the case of IEEE 802.11p (5.8 MHz band), the actual radio wave reach is about 50 m and the transmission band is 12 Mbps at the maximum, so the transfer capacity that can be transferred is 7.5 MB at most.

  Therefore, in the distance measurement data collection, it is necessary to transfer a distance measurement data amount of about 5 to 200 times compared to the transfer capacity by road-to-vehicle communication. The traffic volume is assumed to be at least 300 units / hour (traffic signal installation standard), and about 1000 units / hour / lane in urban areas, and roadside equipment communicates with multiple in-vehicle devices, and the transfer capacity by multiple in-vehicle devices. If is shared, this magnification will be further increased. In addition, when the amount of sensor data increases due to the use of a large number of sensors or the use of an in-vehicle camera, the magnification naturally increases and the transfer capacity is relatively limited.

  FIG. 2 is a schematic diagram of the sensor data collection system. FIG. 2 shows a simplified sensor data collection system, and details of the configuration of the sensor data collection system will be described later with reference to other drawings. As shown in FIG. 2, the sensor data collection system includes one or more vehicles, two or more roadside devices, and a center device.

  The vehicle is equipped with a sensor that measures the surrounding environment of the vehicle and an in-vehicle device that is connected to the sensor and accumulates measurement data from the sensor and transmits the accumulated measurement data to the roadside device. The in-vehicle device and the roadside device are connected by road-to-vehicle communication, and instructions and measurement data are transmitted. The roadside device and the center device are connected by wide area network communication, and instructions and measurement data are transmitted.

  Road-to-vehicle communication can be connected and communicated when the vehicle and the roadside unit are close to each other due to the limitation of the communication range (distance where wireless communication is possible). When the vehicle passes near the roadside machine X, moves toward the roadside machine Y, and passes near the roadside machine Y, the vehicle is first connected to the roadside machine X and can communicate, and then the roadside machine Y When it approaches, it will be connected to the roadside machine Y and can communicate. Further, when the vehicle leaves the roadside machine X, it cannot communicate with the roadside machine X, and thereafter, as the vehicle leaves the roadside machine Y, it cannot communicate with the roadside machine Y. Whether or not the vehicle can communicate with both the roadside machine X and the roadside machine Y simultaneously depends on the distance between the roadside machine X and the roadside machine Y and the arrival state of the radio wave. Here, for the sake of simplicity, it is assumed that communication is possible only with one of the roadside devices. This restriction can be easily done by restricting communication on the roadside device side based on the radio wave intensity and position output by the in-vehicle device, or by selecting one of the roadside devices on the basis of the radio wave strength etc. It is feasible.

  The sensor data collection system finally collects environmental information measured when the vehicle travels in the center device. A sensor on the vehicle measures environmental information, accumulates the measurement data in the in-vehicle device, and the in-vehicle device transmits the measurement data to the roadside device. The roadside device transmits measurement data received from the in-vehicle device to the center device via the wide area network. In the sensor data collection system, in order to limit the amount of data handled by roadside devices and in-vehicle devices and reduce the required hardware and communication resources, the geographical range of environmental information (measurement data) collected by each roadside device is reduced. limit. Specifically, each roadside device collects environmental information on a route (route between roadside devices) from another roadside device to its own roadside device. Due to such a limitation, the in-vehicle device can erase or overwrite the environmental information measured before passing the roadside device after passing through a certain roadside device, thereby reducing the necessary hardware resources.

  It supplements about the path | route (roadside machine path | route) from another roadside machine to the own roadside machine. The roadside machine route is a road that reaches the roadside machine from another roadside machine. FIG. 3 is an example of a path-to-machine path that reaches the roadside machine Y that is the own roadside machine. Even if it is limited to the shortest route, the route from the roadside device X to the roadside device Y is only the straight route 1, while the roadside device X2 to the roadside device Y has two routes, a route 2 and a route 3. . In other words, there can be a plurality of roadside machine paths even if the roadside machine combination is the same, and it is not always possible to uniquely determine the path only by the roadside machine combination. In addition, if the limitation of the shortest route is removed, there can be many more routes, for example, a route that returns from the roadside device Y to the roadside device Y without passing the vicinity of another roadside device can be taken. The sensor data collection system collects environmental information on each route after distinguishing those routes, regardless of the route.

  An outline of processing in the sensor data collection system will be described with reference to a sequence diagram. Details of the processing will be described later, and an outline will be described here. FIG. 4 is a sequence diagram illustrating the processing flow of the roadside device and the vehicle-mounted device in the sensor data collection system. In FIG. 4, the lower direction of the figure shows the passage of time, and the processing in the roadside devices X and Y and the vehicle-mounted device when the vehicle in FIG. 2 passes the roadside device X and travels toward the roadside device Y. It represents the contents and information transmission between the roadside machine and the vehicle-mounted machine.

  When the vehicle passes through the roadside device X, the onboard device transfers the measurement data to the roadside device X, the roadside device X transfers the information on the roadside device X, and when the passage is completed, the onboard device records the information on the roadside device X. To do. Completion of passing, for example, when the response to the communication to the roadside device X was not obtained within a predetermined time, the strength of the radio wave output by the roadside device X (reception strength by the in-vehicle device) became below the predetermined value, the roadside It is detected on the condition that the distance from the machine X is a predetermined distance or more. The information of the roadside device X to be recorded includes at least the ID, passage time, and position information of the roadside device X. The ID of the roadside machine is an identifier that can be distinguished from other roadside machines. For example, the random value obtained when the roadside machine is activated may be used to simplify the implementation, or the position information of the roadside machine may be used as it is. The data amount may be reduced by using a format that expresses ID and position information at the same time. As long as the passage time is a common definition for each roadside machine, you can freely decide which time it will pass through.For example, the time when communication with the roadside machine X started or the time closest to the roadside machine X Can be used as the passage time. In FIG. 4, it is assumed that the communication start time with the roadside device X is passed, and the roadside device X is passed at time 15:25. As for the position information, a detection result at the time of measuring environmental information may be used, or position information notified by the roadside device X may be used.

  As the vehicle travels, environmental information (measurement data) measured by the sensor is stored in the in-vehicle device together with the measurement time and the measurement position. The measurement may be performed continuously as in video recording or may be performed discontinuously based on an appropriate opportunity. Examples of the trigger include every predetermined time, every predetermined distance, and every change in the value of measurement data. Further, since the traveling speed of the vehicle is not always constant, the interval between the measurement positions is not constant even when the measurement is performed every predetermined time.

  As the vehicle approaches the roadside device Y, the in-vehicle device starts communication with the roadside device Y. The start of communication is based on the intensity of the radio wave output from the roadside machine Y, but it is the simplest. For example, a signal is sent from the in-vehicle machine to the roadside machine every predetermined time or when the vehicle reaches a predetermined position. One way to do this is to reduce the power consumption of the roadside unit by reducing the frequency with which the roadside unit outputs radio waves. When communication with the roadside device Y starts, the in-vehicle device notifies the roadside device Y of the stored information (ID, passing time, and position information) of the roadside device X.

  The roadside machine Y determines which section of the route from the position of the roadside machine X to the position of the roadside machine Y is necessary (acquisition section) based on the information notified from the in-vehicle device. For the position information of the roadside device Y, a positioning device may be mounted on the roadside device Y, or the current position of the in-vehicle device may be used. When using the current position of the vehicle-mounted device, the roadside device does not need to be equipped with a positioning device, and the cost of the roadside device can be reduced. A method for determining the acquisition section will be described later.

  The roadside device converts the representation of the acquisition section for the in-vehicle device. Specifically, the coordinates representing the position of the acquisition section are converted into the time when the in-vehicle device is estimated to have passed the acquisition section. Then, the roadside device Y notifies the in-vehicle device of the acquisition section converted into time. The in-vehicle device transfers the measurement data of the acquisition section notified from the roadside device Y to the roadside device Y. When the on-vehicle device completes the passage of the roadside device Y, the vehicle-mounted device records the information on the roadside device Y in the same manner as the information on the roadside device X is recorded. The roadside device Y stores the measurement data transferred from the in-vehicle device.

  Note that the transfer of the measurement data from the in-vehicle device to the roadside device Y is not necessarily successful, and the roadside device Y only needs to store the measurement data that can be transferred from the in-vehicle device. That is, the measurement data is transferred below the transfer capacity possible at the location / time. Moreover, it is not always necessary to perform the recording of roadside device information, the acquisition of environmental information, and the transfer of measurement data in the vehicle-mounted device in the order shown in FIG. 4. For example, the roadside device information is recorded and the measurement data is transferred simultaneously. Thus, the positional deviation of the recording of roadside machine information due to fluctuations in transfer time may be suppressed.

  With this sequence, the roadside device Y can acquire environmental information (measurement data) of a part of the roadside machine route to the roadside device Y traveled by the in-vehicle device. Then, by appropriately determining the acquisition section to be notified to each in-vehicle device based on the acquired measurement data as described later, the environment information (measurement data) of the route to the roadside device Y is obtained from the plurality of in-vehicle devices. Can be obtained from. The roadside device Y transmits the stored environment information to the center device via the wide area network when the environment information of all the sections is gathered in each route. Each roadside device transmits environmental information of all routes to each roadside device to the center device, so that environmental information of all routes can be collected in the center device.

  FIG. 5 shows the overall configuration of the sensor data collection system. The sensor data collection system includes a sensor 501, an in-vehicle device 502, a roadside device 503, and a center device 504. The sensor 501 is connected to the in-vehicle device 502 by the wiring 505, the in-vehicle device 502 is connected to the roadside device 503 by the road-to-vehicle communication 506, and the roadside device 503 and the center device 504 are connected by the wide area network communication 507, and can communicate with each other. Here, the wiring 505, road-to-vehicle communication 505, and wide area network communication 506 may be physically connected by an Ethernet (registered trademark) cable or the like, or may be a wireless LAN (Local Area Network) or LTE ( Any medium can be used as long as information can be transmitted by wireless connection using Long Term Evolution). The communication path may be relayed by one or a plurality of relay devices. In addition, the sensor data collection system is not always capable of road-to-vehicle communication. For example, when the vehicle-mounted device 502 and the roadside device 503 are close to each other and wireless communication is possible, it is only necessary to be able to perform communication. The connection between the sensor 501 and the vehicle-mounted device 502, the vehicle-mounted device 502 and the roadside device 503, and the roadside device 503 and the center device 504 do not have to be one-to-one, and may be one-to-many. The connection relationship may change for reasons such as balance. For example, the in-vehicle device 502 may be connected to a plurality of sensors 501, and in some cases, the in-vehicle device 502 connected to a certain roadside device 503 is connected to another roadside device 503 at another time or simultaneously. It doesn't matter.

  Hereinafter, the sensor 501 and the vehicle-mounted device 502 are described as being mounted on the same vehicle, but are not necessarily mounted on the same vehicle. For example, when the sensor 501 is installed on the road and the vehicle travels in the vicinity of the sensor 501, the vehicle-mounted device 502 mounted on the vehicle and the sensor 501 may be connected by wireless communication or the like.

  The sensor 501 measures environmental information and transmits the measured sensor data to the in-vehicle device 502. Examples of sensors include measurement items such as distance, temperature, pressure (atmospheric pressure), density (density of vehicles on the road), time, time (travel time from a predetermined position to another predetermined position), frequency (predetermined distance) Or the number of signs per time), position, etc., and these values are transmitted to the in-vehicle device 502 by analog signals such as voltage and current, or converted digital signals. Note that this transmission does not necessarily have to start from the sensor 501, and for example, a form in which the vehicle-mounted device 502 starts to read the signal of the sensor 501 may be used. In addition, the sensor 501 does not necessarily need to directly measure the environmental information. For example, the sensor 501 is indirectly measured such that the sensor 501 receives and holds data measured by one or more other sensors. May be.

  The in-vehicle device 502 has a configuration in which an arithmetic processing device 508, a storage device 509, a road-vehicle communication device 510, and an input / output device 511 are connected by a shared bus 512. The roadside device 503 has a configuration in which an arithmetic processing device 513, a storage device 514, a wide area network communication device 515, an input / output device 516, and a road-vehicle communication device 517 are connected by a shared bus 518. The center device 504 has a configuration in which an arithmetic processing device 519, a storage device 520, a wide area network communication device 521, and an input / output device 522 are connected by a shared bus 523. The wiring 505, the road-to-vehicle communication 506, and the wide area network communication 507 have been described above. However, the wiring 505 includes the sensor 501 and the input / output device 511 and the road-to-vehicle communication 506 inside the in-vehicle device 502, the roadside device 503, and the center device 504. Is connected to the road-to-vehicle communication device 510 and the road-to-vehicle communication device 517, and the wide-area network communication 507 is connected to the wide-area network communication device 515 and the wide-area network communication device 521, respectively.

  The devices of the same name have the same function in each of the in-vehicle device 502, the roadside device 503, and the center device 504 (hereinafter referred to as each device when collectively handled), and therefore will be described together below. However, unless otherwise stated, each device shall explain the relationship within each device. For example, when the relationship between the arithmetic processing devices 508, 509, 513 and the storage devices 509, 514, 520 is described, the arithmetic processing device 508 and the storage device 509, the arithmetic processing device 513, the storage device 514, and the arithmetic processing device 519 The relationship between the storage devices 520 is described. Unless explicitly described, the relationship between the devices of different devices such as the arithmetic processing device 508 and the storage device 514 is not described.

  The arithmetic processing devices 508, 513, and 519 are arithmetic processing devices represented by a central processing unit (CPU), and execute programs (software) developed on the storage devices 509, 514, and 520. Note that the arithmetic processing devices 508, 513, and 519 may be physically or logically configured by a plurality of CPUs. The storage devices 509, 514, and 520 store programs executed by the arithmetic processing devices 508, 513, and 519, data created when the programs are executed, data to be read, settings, and the like. The program is data in a format that is executed by the arithmetic processing devices 508, 513, and 519. Data or a program may be held inside the program, or a program may be held inside the data. Is for convenience. In addition, although details of the program will be described later, the plurality of programs are logically distinguished based on functions and the like. For example, all the programs may be configured and processed as one program, or may be divided into a plurality of programs. It is also possible to execute it by separating it into threads and processes.

  The storage devices 509, 514, and 520 are, for example, devices including a storage medium capable of holding data and programs such as a memory, a hard disk, or an optical disc (installed at remote locations, road-to-vehicle communication devices 510 and 517, wide area network communication device 515 521, an input / output device 511, 516, 522, etc.), or a combination thereof. In the description of each device, the storage devices 509, 514, and 520 are used to read, write, refer to, and retrieve data, variables, etc. whose storage location is not specified, storage, storage, recording, storage, etc. To do. In the in-vehicle device 502, the storage device 509 also holds data (sensor data) measured by the sensor 501.

  The input / output devices 511, 516, and 522 are devices that input / output information to / from each device. Each of the input / output devices 511, 516, and 522 includes devices such as a switch, a keyboard, a mouse, a microphone, a video camera, a display, or a speaker, or an interface that can be connected to these devices in the bridge device 101. These devices may be connected and functioned. Further, the input / output devices 511, 516, and 522 include those using communication such as serial communication performed via signal cables or radio waves and radio waves such as infrared rays. Each device can receive instructions from the user or administrator of each device and output the result by the input / output devices 511, 516, and 522.

  The road-vehicle communication device 510 and the road-vehicle communication device 517 are devices for exchanging information via the road-vehicle communication 506 between the in-vehicle device 502 and the roadside device 503. The wide area network communication device 515 and the wide area network communication device 521 are devices for exchanging information between the roadside device 503 and the center device 504 via the wide area network communication 507. The road-to-vehicle communication devices 510 and 517 and the wide area network communication devices 515 and 521 can be regarded as a kind of the input / output devices 511 and 516 described above, but are described separately for convenience of explanation. The exchange of information via road-to-vehicle communication 506 and wide area network communication 507 does not always need to be bidirectional. If only information is temporarily transmitted in a specific direction, it is temporarily unidirectional by mode switching etc. It may be configured so that only the information transmission can be performed.

  The sensor data collection system transmits data (sensor data) measured by the sensor 501 to the in-vehicle device 502 via the wiring 505, and transmits the data from the in-vehicle device 502 to the roadside device 503 via road-to-vehicle communication. To the center device 504 via wide area network communication. The collected sensor data is used for detailed road map creation by performing information processing such as statistical processing. When collecting sensor data, the sensor data is not necessarily transmitted in the same form as when measured to the center device 504. For example, the in-vehicle device 502, the roadside device 503, and the center device 504 may perform processing according to the purpose of using data and the convenience of information transmission, such as data compression and statistical processing. In addition, the sensor data collection system is intended for collecting sensor data to the center device 504, particularly for collecting sensor data from the in-vehicle device 502 to the roadside device 503. Therefore, the sensor data utilization method is only illustrated in this embodiment. . In sensor data collection, bit string representation and modulation in information transmission, TCP (Transmission Control Protocol), UDP (User Datagram Protocol), IP (Internet Protocol), Ethernet, and other transmission technologies, information processing microprocessors and programming For the techniques not described here, such as data structure, database, etc., known techniques will be used.

  A configuration of software (program) recorded on the storage device 509 and developed and executed on the storage device 509 by the arithmetic processing device 508 in the in-vehicle device 502 will be described. Here, the characteristic data flow and processing of the vehicle-mounted device 502 of the sensor data collection system will be mainly described, and it is generally necessary to construct a program for performing multiple processing such as overall control and status management. The processing is omitted.

  FIG. 6 shows a software configuration of the in-vehicle device 502. In FIG. 6, a square represents a processing block realized by a program executed by the in-vehicle device 502. Arrows between processing blocks indicate that information or instructions are transmitted in the direction of the arrows.

  The software of the in-vehicle device 502 includes a sensor input unit 601, a sensor data recording unit 602, a road-to-vehicle transmission / reception unit 603, a frame identification unit 604, a roadside unit information recording unit 605, a frame generation unit 606, and a sensor data operation unit 607. Hereinafter, the operation of each processing block and information transmission between the processing blocks will be described.

  The sensor input unit 601 acquires the sensor data from the sensor 501 by controlling the input / output device 511 every predetermined time, and transmits the sensor data to the sensor data recording unit 602. However, the trigger for sensor data acquisition and transmission to the sensor data recording unit 602 is not limited to every predetermined time. For example, when the travel speed of the vehicle fluctuates by acquiring at every predetermined distance with reference to position information However, it may be possible to acquire environmental information at a geographically similar density. For example, the sensor input unit 601 records the sensor data at the previous acquisition and transmits it to the sensor data recording unit 602 only when there is a change. Thus, the amount of data necessary for recording sensor data may be reduced. In addition, the sensor data can be acquired by using a simple structure of the sensor 501 as a mode in which the sensor input unit 601 issues an acquisition instruction from the input / output device 511 to the sensor 501 and receives the sensor data. However, the form of sensor data acquisition is not limited to this. For example, the sensor input unit 601 is configured to receive the sensor data automatically output by the sensor 501 and notify the sensor input unit 601 of the sensor data. The computational resources required for control may be reduced.

  The sensor data recording unit 602 records the sensor data transmitted from the sensor data input unit 601 so that it can be referred to later. The contents of the sensor data will be described later.

  The road-to-vehicle transmission / reception unit 603 controls the road-to-vehicle communication device 510 to transmit / receive a frame (data transmission / reception unit) via the road-to-vehicle communication. When the road-to-vehicle transmission / reception unit 603 receives a frame for road-to-vehicle communication from the outside, it transfers the frame to the frame identification unit 604. The frame identifying unit 604 identifies a process to be executed by the vehicle-mounted device 502 and parameters for the process (information on the roadside device 503 and an acquisition section described later) from the contents of the transferred frame. These identified processes and parameters will be described later. The frame identification unit 604 transfers the information on the roadside machine 503 to the roadside machine information recording unit 605 if it should be recorded, and if the process should be executed on the sensor data recorded in the sensor data recording unit 602, Necessary information (ID of the target roadside machine, range of sensor data to be operated, operation content, etc.) is transferred to the sensor data operation unit 607.

  Based on the information transferred from the frame identification unit 604, the sensor data operation unit 607 deletes the sensor data, reads out the sensor data and transfers it to the frame generation unit 606, or parameter information transferred from the frame identification unit 604 Or the like to the frame generation unit 606. Some or all of these erasing, reading and transfer may be performed simultaneously to streamline processing.

  The roadside machine information recording unit 605 records the information of the roadside machine 503 transferred from the frame identification unit 604. If there is an instruction from the frame generation unit 606, the roadside unit information recording unit 605 reads the recorded information on the roadside unit 503 and transfers it to the frame generation unit 606.

  Based on the parameter information transferred from the sensor data operation unit 607, the frame generation unit 606 reads information on the roadside device 503 from the roadside device information recording unit 605 if necessary. The frame generation unit 606 generates a frame based on parameter information and sensor data transferred from the sensor data operation unit 607 or information on the roadside machine 503 read out by the roadside machine information recording unit 605, and Transfer to the transceiver 603. The road-to-vehicle transmission / reception unit 603 transmits the frame transferred from the frame generation unit to the roadside device 503 through road-to-vehicle communication.

  The configuration of software (program) recorded on the storage device 514 and executed on the storage device 514 by the arithmetic processing device 513 in the roadside machine 503 will be described. Here, the characteristic data flow and processing of the roadside unit 503 of the sensor data collection system will be mainly described, and it is generally necessary to construct a program for performing multiple processing such as overall control and status management. The processing is omitted.

  FIG. 7 shows a software configuration of the roadside machine 503. In the figure, a square represents a processing block realized by a program executed by the roadside machine 503. Arrows between processing blocks indicate that information or instructions are transmitted in the direction of the arrows.

  The software of the roadside machine 503 includes a road-to-vehicle transmission / reception unit 701, a frame identification unit 702, a sensor data management unit 703, an overall route calculation unit 704, an acquisition section determination unit 705, a passage time estimation unit 706, a roadside machine information generation unit 707, a frame A generation unit 708, a wide area network transmission determination unit 709, a sensor data operation unit 710, a wide area network transmission data generation unit 711, and a wide area network transmission / reception unit 712 are included. Hereinafter, the operation of each processing block and information transmission between the processing blocks will be described.

  The road-to-vehicle transmission / reception unit 701 controls the road-to-vehicle communication device 517 to transmit / receive a frame (data transmission / reception unit) via road-to-vehicle communication. When the road-to-vehicle transmission / reception unit 701 receives a frame from the in-vehicle device 502, the road-to-vehicle transmission / reception unit 701 transfers the frame to the frame identification unit 702. The frame identifying unit 702 refers to the content of the transferred frame, and identifies the process to be executed by the roadside device 503 and parameters for the process (information on the in-vehicle device 502, sensor data, and the like). These identified processes and parameters will be described later together with the process of the roadside machine. The frame identification unit 702 notifies the acquisition section determination unit 705 if the information on the in-vehicle device 502 is to be notified, and notifies the sensor data management unit 703 if the sensor data is to be notified together with the information on the in-vehicle device 502. The information on the vehicle-mounted device 502 to be notified and the contents of the sensor data will be described later.

  The sensor data management unit 703 stores the notified information on the in-vehicle device 502 and the sensor data, and instructs the entire route calculation unit 704 to calculate the entire route. The entire route calculation unit 704 reads the sensor data stored from the sensor data management unit 703, calculates the entire route, and transmits the result to the acquisition section determination unit 705 and the wide area network transmission determination unit 709. A method for calculating the entire route (overall route extraction process) will be described later. The acquisition section determination unit 705 determines the acquisition section of the route using the information on the in-vehicle device 502 notified from the frame identification unit 702 and the information about the entire route notified from the entire route calculation unit 704, and passes This is transmitted to the time estimation unit 706. Information on the entire route and a method for determining the acquisition section will be described later. The passage time estimation unit 706 estimates the time when the in-vehicle device 502 passes through the acquisition section and notifies the frame generation unit 708 of the time. The estimation method will be described later. The roadside machine information generation unit 707 generates information on the roadside machine 503 and notifies the frame generation unit 708 of the information. Information on the roadside machine 503 will be described later.

  The frame generation unit 708 generates a frame using the notified information and notifies the road-vehicle transmission / reception unit 701 of the frame. The road-to-vehicle transmission / reception unit transmits the notified frame via road-to-vehicle communication. The wide area network transmission determination unit 709 determines whether to transmit to the wide area network from the information regarding the entire path notified from the entire path calculation unit 704, and notifies the sensor data operation unit 710. The determination method will be described later. The sensor data operation unit accesses the sensor data management unit 703 based on the notified information, and reads or deletes the sensor data. In addition, the read sensor data is notified to the wide area network transmission data generation unit 711. The wide area network transmission data generation unit 711 processes the notified sensor data, generates data to be transmitted to the wide area network, and notifies the wide area network transmission / reception unit 712 of the data. The processing method will be described later. The wide area network transmission / reception unit 712 controls the wide area network communication device 515 to transmit / receive data to / from the center device 504 through the wide area network communication 507. The wide area network transmission / reception unit 712 transmits the data notified from the wide area network transmission data generation unit 711 via the wide area network.

  In the above-described software configuration, a part of the information mentioned later will be described. The remaining part will be described later in the explanation of the operation according to the flowchart.

  FIG. 8 is an example of sensor data held in the sensor data recording unit 602. The sensor data includes time 801, position 802, sensor type 803, and sensor value 804. The time 801 is time information when the sensor 501 measures the sensor value 804. For example, the time 801 is obtained by counting from the vibration of the crystal oscillator or being notified from the satellite positioning system. Hereinafter, it is assumed that the time is synchronized with the entire sensor data collection system. The synchronization is realized by a known technique such as Network Time Protocol or satellite positioning system.

  The position 802 is coordinate information indicating the position of the sensor 501, and a known one such as the World Geodetic System 1984 (WGS84) is used, and the same coordinate system is used in the entire sensor data collection system. Note that the coordinate information is not limited to that described above. For example, an in-vehicle device 502 and a roadside device 503 add a mechanism for mutual conversion using different geodetic systems, so that more manufacturers' devices can be used. It may be configured to operate even when combined, or may be expressed by relative coordinates from a specific position to reduce the memory capacity necessary for holding coordinate information.

  The sensor type 803 is information for distinguishing the type of the sensor 501. By adding the sensor type 803, one vehicle-mounted device 502 can be connected to a plurality of sensors 501, and the values measured by the plurality of sensors 501 can be distinguished and held or used. If it can be determined from information that the sensor type 803 is fixed, information such as the time 801, etc., the sensor type 803 may be omitted to reduce the memory capacity necessary for holding sensor data.

  A sensor value 804 is a value measured by the sensor 501. The expression, number, accuracy, etc. of the values may differ depending on the sensor 501, and the memory capacity necessary for holding sensor data may be reduced by performing compression or the like from the expression output by the sensor 501. The representation of the sensor data shown in FIG. 8 is not only when held by the sensor data recording unit 602, but also sensor data transmitted from the vehicle-mounted device 502 to the roadside device 503, or from the frame identification unit 702 to the sensor data management unit 703. It is also used as a representation of notified sensor data. Note that the notification from the sensor 501 to the in-vehicle device 502 transmits only the sensor value 804, not this expression. By transmitting only the sensor value, the data transfer capacity required for the wiring 505 can be reduced, and the structure of the sensor 501 can be simplified. It should be noted that the expression when transmitting from the sensor 501 to the vehicle-mounted device 502 is not necessarily limited to the sensor value 804. For example, the transfer capacity and memory capacity required for processing may be reduced by performing compression. The calculation amount required in the in-vehicle device 502 may be reduced by using the sensor data expression shown in FIG. 8 as it is and omitting the conversion process of the sensor data expression in the in-vehicle device 502.

  Information on the in-vehicle device 502 and information on the roadside device 503 will be described. The information on the vehicle-mounted device 502 is an identifier for identifying the plurality of vehicle-mounted devices 502 in the roadside device 503, and may be unique when the vehicle-mounted device 502 communicates with the roadside device 503. As this identifier, address information used in road-to-vehicle communication such as a MAC (Media Access Control) address is used. Using address information ensures uniqueness and consistency during communication. In addition, although not essential, since it is possible to collate with sensor data held by another roadside machine 503, it can be used for integration of sensor data of a plurality of roadside machines. Note that the identifier as information on the in-vehicle device 502 is not limited to address information, and for example, a value may be set at random when communication with the roadside device 503 is started. By setting a value randomly from a sufficiently large range (for example, 64 bits), it is possible to effectively avoid identifier collision and prevent tracking of the in-vehicle device 504 across multiple roadside devices 503, making it anonymous Can be improved.

  Note that the information on the in-vehicle device 502 is included in a frame transmitted from the in-vehicle device 502 to the roadside device 503 via the road-to-vehicle communication 506. Also, since this identifier only needs to be different from each other, it is not always necessary to use the value included in the frame as it is. For example, by applying a function such as a hash to convert the value, the anonymity of the held sensor data is improved. Also good.

  On the other hand, the information on the roadside device 503 includes time information, position information, and an identifier of the roadside device 503 acquired when the in-vehicle device 502 passes through the roadside device 503. The time information and the position information are information having the same name described with reference to FIG. 8, and the identifier of the roadside device 503 is an identifier unique to all the roadside devices 503. The position information and time information are acquired from the sensor 501 and the like by the in-vehicle device 502, and the identifier is generated by the road-side device information generation unit 707 and transmitted from the road-side device 053 to the in-vehicle device 502 by the frame of the road-to-vehicle communication 506. Is done. Here, in the roadside machine information generation unit 707, the MAC address is used as an identifier, but the method of acquiring information of the roadside machine 503 is not limited to this. For example, a sensor that acquires position information is connected to the input / output device 516 of the roadside machine 503, and the roadside machine information generation unit 707 controls the sensor to acquire the position information. By transmitting the information to 503 and making the position information and the identifier the same, it is possible to reduce the calculation resources necessary for transmitting and holding the information.

  FIG. 9 is a sensor data management table held by the sensor data management unit 703 in the roadside device 503. The sensor data held by the sensor data management unit 703 has a configuration in which the section ID 902 is added to the sensor data shown in FIG. Information other than the section ID 902 in FIG. 9 is the same as the information of the same name in FIG. The roadside device 503 acquires the information in FIG. 8 from the in-vehicle device 502 via the road-to-vehicle communication 506. The section ID 902 is an identifier (corresponding to a session ID) for distinguishing communication between the in-vehicle device 502 and the roadside device 503. Even in the same roadside device 503, communication with different on-vehicle devices 502 has different section IDs 902, and even communication with the same on-vehicle device 502 is different from each other when passing through the roadside device 503 twice. It has section ID 902. The section ID 902 is realized by linking the information on the vehicle-mounted device 502, the information on the roadside device 503, and the time information when the session of the road-to-vehicle communication 506 is established. In this realization method, the information before connection can be restored from the section ID 902 and used for statistical processing. Note that the method of realizing the section ID 902 is not limited to this. For example, the processing may be simplified by adding 1 to each session to reduce the amount of computer resources necessary for the implementation. Even if it is simplified, if a table that holds and associates the section ID 902 with the above-mentioned linked information is created separately, the same processing as the section ID 902 by the above-mentioned coupling can be realized, and if the processing is unnecessary It may be omitted.

  FIG. 10 is a process flowchart of the in-vehicle device and the roadside device. In FIG. 10, the left half represents processing in the in-vehicle device 502, and the right half represents processing in the roadside device 503. In FIG. 10, the broken-line arrows connecting the left half and the left half are added for the sake of explanation, and represent the transmission of information via the road-to-vehicle communication 506. The solid line representing the process transition in the flowchart The meaning is different from the arrow. In FIG. 10, squares represent processing, S1000 to S1010 represent processing steps executed by the arithmetic processing device 508 of the in-vehicle device 502, and S1100 to S1113 executed by the arithmetic processing device 513 of the roadside device 503. Represents a processing step. Hereinafter, the main body that executes the processing is the arithmetic processing device 508 or 513, but the processing may be realized by each device in the in-vehicle device 502 and the roadside device 503.

  When the in-vehicle device 502 starts processing (S1000), the sensor data acquired from the sensor 501 is stored in the sensor data recording unit 602 (S1001). S1001 corresponds to the part in which the in-vehicle device acquires the environmental information on the route in FIG. The in-vehicle device 502 establishes a connection (session) with the roadside device 503 via the road-to-vehicle communication 506 (S1002). S1002 corresponds to the part in FIG. 4 where the in-vehicle device approaches the roadside device Y and starts communication. The in-vehicle device 502 transmits information on the previous roadside machine that is the roadside machine (roadside machine X in FIG. 4) that has passed immediately before to the communicating roadside machine (roadside machine Y in FIG. 4) (S1003). The roadside machine information in S1003 is information of the roadside machine 503 mentioned in the software configuration, and is held in the roadside machine information recording unit 605 as described above. In addition, when not hold | maintaining, it expresses not having hold | maintained by making time negative, etc., and transmits as roadside machine information. S1003 corresponds to the notification of “passing X at 15:25” from the in-vehicle device to the roadside device Y in FIG. The in-vehicle device 502 receives the acquisition section transmission instruction from the roadside device 503 (S1004). In FIG. 4, S1004 corresponds to a notification from the roadside device Y to the in-vehicle device that “instructs data transmission in the acquisition section”.

  The in-vehicle device 502 refers to the frame content in the frame identification unit 604 (S1005), and the acquisition section corresponds to the previous roadside machine (roadside machine X in FIG. 4) to the current roadside machine (roadside machine Y in FIG. 4). If so, it is considered that the roadside device is instructing sensor data transfer, and the process proceeds to S1006. Otherwise, the process proceeds to S1009. FIG. 4 shows an example of proceeding from S1005 to S1006.

  The in-vehicle device 502 extracts the sensor data designated as the acquisition section from the roadside device information recording unit 605 (S1006). The in-vehicle device 502 checks whether communication via the road-to-vehicle communication 506 is possible, and determines if there is any unsent sensor data extracted if possible (S1007). If true, the process proceeds to S1008 If it is false or communication is not possible, the process proceeds to S1009. Whether or not communication is possible in S1007 is determined based on whether or not the radio field intensity of the roadside unit 503 (the radio field intensity received by the in-vehicle unit 502) is equal to or greater than a predetermined value, whether a response signal can be received, or the like. The in-vehicle device 502 divides the sensor data extracted in S1006 into an amount that can be transmitted by the frame of the road-to-vehicle communication 506, if necessary, by the sensor data operation unit 607, and generates a frame by the frame generation unit 606. The inter-vehicle transmission / reception unit 603 transmits sensor data to the roadside device 503 via the road-to-vehicle communication 506 (S1008), and the process proceeds to S1007. In step S1008, the sensor data operation unit 607 records how far the sensor data extracted in step S1006 has been transmitted so that the transmitted data can be distinguished. In S1008, when dividing and transmitting a plurality of frames, sensor data with a later time is transmitted first. Note that the confirmation of whether communication in S1007 is possible may be omitted to simplify the process, but if omitted, transmission in S1008 will always be performed, so the transfer efficiency of road-to-vehicle communication 506 deteriorates. It will be. Further, by repeating S1007 and S1008, the sensor data extracted in S1006 is transmitted, which corresponds to “transmit instructed data” in the in-vehicle device in FIG.

  The in-vehicle device 502 instructs the sensor data operation unit 607 to delete the sensor data up to the current roadside device, and the sensor data recording unit 602 deletes the corresponding sensor data (S1009). In S1009, it is not necessary to record the sensor data indefinitely by deleting the sensor data, so that the storage capacity of the storage device 509 can be reduced. The designation of the sensor data to be deleted in S1009 can be realized by, for example, the process of deleting the sensor data before the passage time of the roadside machine Y described in FIG. The in-vehicle device 502 stores the roadside machine information (the information on the roadside machine 503 described above) of the current roadside machine (roadside machine Y in FIG. 4) in the roadside machine information recording unit 605 (S1010), and proceeds to S1001. S1010 corresponds to “record information of roadside device Y” in the in-vehicle device in FIG.

  When the roadside device 503 starts processing (S1100), the overall route calculation unit 704 performs overall route extraction processing, and updates the section management table held by the overall route calculation unit 704 (S1101). The entire route extraction process and the section management table will be described later. In S1102, the roadside device 503 establishes a connection (session) with the in-vehicle device 502 via the road-to-vehicle communication 506 (S1102). S1102 corresponds to the part where the in-vehicle device approaches the roadside device Y and starts communication in FIG. The roadside device 503 receives the previous roadside device information transmitted from the in-vehicle device 502 in S1003 (S1103). S1103 corresponds to the part in FIG. 4 where the roadside device Y receives the information “pass X through 15:25”.

  The roadside device 503 scans the route extracted in S1101, and the wide area network transmission determination unit 709 determines whether there is no partial route and the start point of all the entire routes is the adjacent roadside device (S1104). If yes, go to S1108. The partial route, the whole route, and the starting point will be described later together with the whole route extraction process.

  The roadside device 503 processes the sensor data held in the sensor data management unit 703 by the wide area network transmission data generation unit 711 (S1105). The processing performed here will be described later. The roadside device 503 transmits the sensor data processed in S1105 to the center device 504 via the wide area network communication 507 by the wide area network transmission / reception unit 712 (S1106). The roadside machine 503 processes in S1105, deletes the sensor data transmitted to the center in S1106 (S1107), and proceeds to S1101. The sensor data operation unit 710 instructs the sensor data management unit 703 to delete the sensor data.

  The roadside device 503 selects a route having the shortest distance between the start point and the end point from the entire route from the previous roadside device, and sets the acquisition section from the previous roadside device to the start point (S1108). In S1108, when there is no whole route or there is a partial route that is not incorporated in the whole route, the whole route from the previous road side machine to the current road side machine is set as the acquisition section. Details of the acquisition section determination method in S1108 will be described later.

  The roadside device 503 estimates the start point passage time of the acquisition section in S1108 (S1109). The starting point passage time in S1109 is the passage time (t0) of the previous roadside machine received in S1103, the arrival time (t1) to the current roadside machine, the time of the sensor data of the starting point stored in the sensor data management unit 703 (t2 ), Calculated as `` t0 + (t1-t0) * (t2-t3) / (t4-t3) '' from the passage time (t3) and arrival time (t4) of the start point sensor data stored in the section management table . The roadside machine 503 adds a predetermined time (for example, twice the average sensor value acquisition interval or an assumed interval described later) to the start point passage time estimated in S1009 as an acquisition interval, and performs road-vehicle communication 506. To the in-vehicle device 502 and instruct the in-vehicle device 502 to transmit the sensor data (S1110). The reason why the predetermined time is added in S1009 is to make the sections of sensor data received from each vehicle-mounted device overlap on the route. The instruction from the roadside device 503 in S1110 is received by the in-vehicle device 502 in S1004.

  The roadside device 503 confirms whether or not the road-to-vehicle communication S506 is available (S1111). If it is available, the process proceeds to S1112. Otherwise, the process proceeds to S1113. Whether or not communication is possible in S1111 is the same as in S1007. Further, it is treated that communication is not possible if there is no reception for a predetermined time (for example, 1 second). In S1112, the roadside device 503 receives the sensor data from the in-vehicle device 502, stores it in the sensor data management unit 703 (S1112), and proceeds to S1111. When storing in S1112, if the sensor data interval is longer than the interval that can be assumed as the sensor value acquisition interval (this can be calculated, for example, based on the average value of the sensor data interval or the specifications of the sensor 501, then Do not save sensor data of previous time. This is because the sensor data is received in the order of going back to the front in the time of the acquisition section in S1112 by sending the sensor data whose time is later in S1008, but the reception in S1112 and the sensor 501 This is because when there is a missing environmental information measurement, sensor data before the missing time is not saved, and the missing is eliminated. The roadside device 503 stores the information of the previous roadside device notified in S1103 in the section management table (S1113), and proceeds to S1101.

  In the processing performed in S1105, the sensor value accumulated in each vehicle-mounted device 502 mounted on a plurality of vehicles varies depending on the time, position (travel lane), sensor 501, etc., even if traveling on the same route. Considering this, it means that the sensor value of the route is converted into a value that seems most appropriate from a plurality of sensor data related to the same route. As an example of processing, a large number of sensor data obtained by measuring the same path is first normalized by linear interpolation with respect to the position in the path direction, and then the average of sensor values at the same position on the path is taken. Normalization of the position in the path direction is, for example, when sensor values are acquired at predetermined time intervals, and the sensor value acquisition interval increases as the vehicle traveling speed increases. This is because the position where the sensor value is acquired by the vehicle sensor is shifted. The processing performed in S1105 is not limited to this. For example, if the sensor value on the path can be predicted as a function with respect to the position, there may be processing in which the function is represented by a parameter representing the function. Specifically, for example, if the sensor value can be approximated to a straight line that increases in proportion to the distance from the front roadside machine, the sensor value can be expressed as a proportional constant and an offset value with respect to the distance. In these processes, since the number of samples of sensor values can be adjusted, for example, the amount of data to be transferred over a wide area network can be reduced at the expense of accuracy. In addition, an example of processing in which the sensor value is code-compressed is also conceivable. Of course, processing that does not convert at all can be considered, processing that extracts values at random can be considered, and combinations of these various processing methods can also be considered. Here, the processing method is not limited, and appropriate processing is performed in accordance with the environmental information acquired by the sensor and the purpose of use of the environmental information.

  FIG. 11 is an example of a section management table held by the overall route calculation unit 704. The section management table is a table in which a section ID 1301 is associated with a passage time 1302, a position 1303, a roadside machine ID 1304, an arrival time 1305, and a path ID 1306. The section ID 1301 is the same as the section ID 902. The passage time 1302, the position 1303, and the roadside machine ID 1304 are the passage time, position information, and identifier of the previous roadside machine, respectively, and are notified from the in-vehicle device in S1103 as information of the roadside machine 503. The arrival time 1305 is the arrival time at the current roadside machine, and is the time when S1103 is executed. The route ID 1306 is an identifier of the whole route obtained by the whole route extraction process described later, and zero or more route IDs are associated with one section ID 1301. When the number of associated route IDs is 0, this indicates a case where there is no associated overall route, and when the number is 1 or more, it indicates that the associated route ID is associated with one or more overall routes.

  The entire route extraction process performed in S1101 will be described. FIG. 12 is a flowchart of the overall route extraction process performed by the overall route calculation unit 704 of the roadside device 503. The entire route extraction process is acquired by each of the roadside machine paths (see the description of FIGS. 3 and 3) to the current roadside machine 503 and a plurality of vehicles, collected in the roadside machine 503, and collected by the sensor data management unit 703. Is associated with the sensor data stored in the sensor data management table.

  When the process is started (S1200), the entire route calculation unit 704 of the roadside device 503 reads the sensor data stored from the sensor data management unit 703, and from the previous roadside device notified in S1103 to the current roadside device. Route sensor data is extracted (S1201). This is a process of extracting the sensor data of the route (route 2 and route 3) of the roadside device X2 when the roadside device Y in FIG. 3 is notified in S1103 that it came from the roadside device X2. This is because the sensor data of a predetermined route can be extracted by selecting the section ID 902 of the sensor data management table corresponding to the section ID 1301 whose roadside machine ID 1304 of the section management table is the previous roadside machine X2.

  The overall path calculation unit 704 creates a partial path from which the position information of the sensor data extracted in S1201 is extracted (S1202). The partial paths are distinguished from other partial paths by an identifier, a plurality of pieces of positional information are associated with a certain identifier, and are held in a state in which there is an order relationship between the plurality of associated pieces of positional information. As described with reference to FIG. 9, since sensor data is distinguished by section IDs in the sensor data management table, partial paths can be managed in the form of associating identifiers with section IDs, and it is not necessary to have separate location information Absent.

  The entire route calculation unit 704 starts from the position where the time is first in the partial route, starts from the position where the time is last, and a part of the route from the start point to the end point of a certain partial route starts from the end point of another partial route. A pair of partial paths that overlap with a part of the path to the starting point is searched (S1203). If found, the process proceeds to S1204, and if not found, the process proceeds to S1205. Note that the term “overlap” means that an appropriate number of pieces of position information continuous from the start point of one partial path are sufficiently close to an appropriate number of pieces of position information consecutive from the end point of the other partial path. Here, “close enough” means that the position information of other partial paths exists at a distance shorter than the maximum distance between the position information in the partial paths.

  The overall route calculation unit 704 treats a route obtained by combining overlapping routes as a new part (S1204), and proceeds to S1203. The combination is performed by associating the position information included in the existing overlapping partial path with the identifier of the new partial path, and the order relationship of the overlapping parts is between the position information arranged in the direction from the start point to the end point. This is performed by arranging so that one piece of position information of the other partial path comes at a position closer to the distance between two pieces of continuous position information of one partial path. If location information that is not arranged by this method is included, it is only necessary to treat the partial routes as non-overlapping and exclude them from the overlapping partial route pairs in the subsequent S1203.

  The total route calculation unit 704 extracts a partial route whose position information serving as the end point of the partial route is sufficiently close to the position of the current roadside device as the entire route (S1205). Here, “close enough” means that the distance between the end point and the position of the current roadside machine is shorter than the maximum distance between the position information included in the partial route. The overall route calculation unit 704 updates the route ID 1306 in the section management table (S1206), and ends the processing (S1207). Through the processing of the entire route calculation unit 704, the section ID and the entire route are associated with each other.

  Details of the determination of the acquisition section performed by the roadside device 503 in S1108 will be described. FIG. 13 is a schematic diagram illustrating the roadside machine-to-machine path, the partial path, and the entire path. In the figure, the current roadside machine 1501 represents the roadside machine Y in FIG. 2, the front roadside machine 1502 represents the roadside machine X in FIG. 2, and dotted lines R1402 to R1405 connect the front roadside machine 1502 and the current roadside machine 1501. Represents a road or part of it. There can be three paths R1404 + R1403, R1405 + R1403, and R1402 between the roadside machines between the front roadside machine 1502 and the current roadside machine 1501. Hereinafter, the operations of the in-vehicle device 502 and the roadside device 503 will be described with reference to this drawing, with examples. For easy understanding, the main part of the steps shown in FIG. 10 will be described.

  Now, assume that a vehicle travels on one of the roads R1402 to R1405 from the previous roadside machine 1502 toward the current roadside machine 1501, and environmental information is acquired in units of 1 meter during the running. Assume that when passing the current roadside device 1501, the acquired environmental information is transferred from the in-vehicle device 502 to the current roadside device 1501 as sensor data. Since the transfer capacity of road-to-vehicle communication 506 is limited, not all sensor data acquired on the route can be transmitted, and the roadside device 503 transmits sensor data corresponding to the acquired section determined in S1108. .

  In the initial state, the current roadside device 1501 does not hold the sensor data of any route, so the acquisition section is the entire area from the previous roadside device 1502 to the current roadside device 1501. Here, as described in S1008, the in-vehicle device 502 sequentially transmits the data with the later time, so the sensor data on the side closer to the current roadside device 1501 is sequentially transmitted on the route, and the current roadside device 1501 The sensor data is received in the order of transmission from the in-vehicle device 502. If the sensor data for the entire route cannot be sent at one time due to transfer capacity limitations, the current road side device 1501 receives the sensor data from the current road side device 1501 to the middle of the route in S1112 and updates the sensor data management table In step S1113, the section management table is updated.

  For example, if vehicle A first travels R1402, the current roadside machine 1501 receives sensor data of a section close to the current roadside machine 1501 like r1406, and holds it in the sensor data management table and the section management table become. When the current roadside device 1501 executes the entire route extraction process S1101 in this state, only the section r1406 is extracted for both the partial route and the entire route.

  Subsequently, when the vehicle B traveling on R1405 and R1403 passes the current roadside machine 1501, the current roadside machine 1501 is processed in S1108. In S1108, the current roadside machine 1501 selects r1406 because there is no other overall route, and the starting point of r1406 from the roadside machine 1502 (the end point on the roadside machine 1502 side) is determined as the acquisition section. In S1109, the current roadside machine 1501 estimates a time obtained by adding a predetermined time to the time when it passed the start point of r1406 on R1402, and the time when the vehicle B onboard machine passed the front roadside machine 1502 as an acquisition section. Until the time estimated to have passed the starting point of r1406 is notified as an acquisition interval. Here, vehicle B passes R1405 and R1403 instead of R1402, but since the acquisition section is specified by time, the vehicle-mounted device of vehicle B transmits the sensor data of the section r1411, for example, and the current roadside device 1501 receives the sensor data of r1411 in S1112, updates the sensor data management table, and updates the section management table in S1113. When the current roadside device 1501 executes the entire route extraction process S1101, r1406 and r1411 are extracted as partial routes and r1411 is extracted as an entire route.

  Here, when the vehicle C that has further traveled R1404 and R1403 passes through the current roadside machine 1501 and the current roadside machine 1501 executes S1108, for r1411, since there is only a partial path and no entire path exists, in S1108 All routes from the roadside machine 1502 to the current roadside machine 1501 are determined as acquisition sections, and the vehicle-mounted device 502 of the vehicle C transmits r1410 (sensor data) to the current roadside machine 1501, and the current roadside machine 1501 has a sensor data management table. And the section management table is updated. When the current roadside device 1501 executes the entire route extraction process S1101 in this state, r1411 and r1410 are integrated because they overlap, and r1406 and r1410 + r1411 are extracted as the entire route.

  Here, when the vehicle D that has traveled R1404 and R1403 passes the current roadside machine 1501 and the current roadside machine 1501 executes S1108, there is no partial path that is not incorporated in the entire path in the current roadside machine 1501 at this time. Since r1406 is the shortest overall route, the starting point of r1406 is notified as an acquisition section, but since vehicle D is traveling on R1404 and R1403 instead of R1402, r1412 is transmitted to the current roadside machine 1501, The roadside device 1501 receives it. At this point, the current roadside device 1501 holds r1406, r1411, r1410, and r1412. In this state, when the current roadside device 1501 executes the entire route extraction process S1101, r1411 + r1410, r1412 + r1410, r1406 are extracted as the entire route. R1410 is integrated because the partial routes and sections of r1411 and r1412 overlap, but the starting points of r1411 and r1412 are on different roads R1405 and R1404, so they are extracted as different whole routes. As described above, the current roadside machine 1501 is repeatedly divided into r1406 to r1416 by repeatedly updating the entire route, determining the acquisition section, and receiving the sensor data when the vehicle is passing. , R1402, R1403, R1404, and R1405 roads, that is, sensor data for all roadside machine-to-machine routes are acquired.

  In this way, sensor data of all roadside machine path is acquired, so R1403 + R1405 is r1410 + r1411 + r1413 + r1415, R1404 + R1403 is r1410 + r1412 + r1414 + r1416, R1402 Since it is covered by the entire route of r1406 + r1407 + r1408 + r1409 and the starting point of each overall route is the front roadside machine 1502, the judgment result of S1104 becomes true, and the processing after S1105 and wide area network transmission are performed . In this embodiment, for simplicity, the process proceeds to S1105 with all roads covered, but the present invention is not limited to this. For example, the condition of S1104 is relaxed so that it is true if the starting point of any of the entire routes is the previous roadside machine 1502, and S1105 to S1107 are executed only for the entire route, The center device 504 may obtain sensor data more frequently. Alternatively, when extracting the entire route in S1101, a plurality of sensor data is always obtained for all the roads, which are extracted as an entire route only when partial routes composed of different sections all cover the same road. By setting the obtained conditions, when processing is performed in S1105, a statistical value such as an average or variance may be obtained with a plurality of sensor data for the same route.

  In the embodiment described above, the time corresponding to the unacquired route is notified to the vehicle-mounted device as the method for determining the acquisition interval and the method for specifying the acquisition interval to the vehicle-mounted device 502. It is not limited and can be applied in various ways.

  For example, by using a camera image as sensor data and specifying a section including a position where a sign or a traffic light is present as an acquisition section, it can be used to check the deterioration status or visibility of the sign or the traffic light. In addition, by specifying an interval that includes already acquired as well as an unacquired portion of the route when determining the acquisition interval, multiple sensor data are acquired for the same route, and the average or median value is taken. Variations can be reduced, or abnormal values can be extracted by comparison and warnings about road conditions can be issued.

  Further, in the embodiment described above, a mode in which sensor data of a moving in-vehicle device is aggregated by a fixed roadside device is shown. However, a mode in which sensor data of a fixed roadside device is aggregated in a moving in-vehicle device is also possible. possible. In this case, on the assumption that a plurality of in-vehicle devices pass (including the case where the same in-vehicle device passes a plurality of times), a section that is not yet aggregated by the in-vehicle devices from the in-vehicle device to the roadside device is requested.

  501: Sensor, 502: In-vehicle device, 503: Roadside device, 504: Center device, 601: Sensor input unit, 602: Sensor data recording unit, 603: Road-to-vehicle transmission / reception unit, 604: Frame identification unit, 605: Roadside device information Recording unit, 606: Frame generation unit, 607: Sensor data operation unit, 701: Road-to-vehicle transmission / reception unit, 702: Frame identification unit, 703: Sensor data management unit, 704: Overall route calculation unit, 705: Acquisition section determination unit, 706: transit time estimation unit, 707: roadside device information generation unit, 708: frame generation unit, 709: wide area network transmission determination unit, 710: sensor data operation unit, 711: wide area network transmission data generation unit, 712: wide area network transmission / reception , 1501: Current roadside machine, 1502: Front roadside machine.

Claims (20)

An in-vehicle device that transmits an identifier of the first roadside device, and transmits sensor data of the section in response to designation of the section; and
In response to receiving the identifier of the first roadside device from the vehicle-mounted device, a second section that designates the section on the route from the first roadside device and receives the sensor data from the vehicle-mounted device. A sensor data collection system comprising a roadside machine.   The sensor data collection system according to claim 1, wherein the designation of the section is designation of an estimated time when the in-vehicle device passes the section.   The second roadside machine refers to the position information obtained by measuring the measurement data included in the sensor data, and when the position information is not included in the section, the sensor data is transmitted to another section different from the section. 3. The sensor data collection system according to claim 2, wherein the sensor data collection system is a sensor data. The vehicle further includes another in-vehicle device that transmits the identifier of the first roadside device and transmits other sensor data of the other section in response to designation of the other section.
The second roadside machine is different from the section on the route from the first roadside machine in response to receiving the identifier of the first roadside machine from the other vehicle-mounted machine. The sensor data collection system according to claim 1, wherein the other sensor data is received from the other vehicle-mounted device.   The second roadside machine has at least the sensor data from the vehicle-mounted device and the other sensor data from the other vehicle-mounted device, and the same roadmap from the first roadside device to the second roadside device. 5. The sensor data collection system according to claim 4, wherein the sensor data is a route sensor data. A sensor data collection method in a sensor data collection system having an in-vehicle device, a first roadside device, and a second roadside device,
The in-vehicle device transmits the identifier of the first roadside device, transmits sensor data of the section in response to the specification of the section,
In response to receiving the identifier of the first roadside device from the in-vehicle device, the second roadside device designates the section on the route from the first roadside device, and from the in-vehicle device. A sensor data collection method comprising receiving the sensor data.   The sensor data collection method according to claim 6, wherein the designation of the section is designation of an estimated time when the in-vehicle device passes the section.   The second roadside machine refers to the position information obtained by measuring the measurement data included in the sensor data, and when the position information is not included in the section, the sensor data is transmitted to another section different from the section. The sensor data collection method according to claim 7, wherein the sensor data is obtained as follows. The sensor data collection system further includes another in-vehicle device,
The other in-vehicle device transmits the identifier of the first roadside device, and transmits other sensor data of the other section in response to designation of the other section,
The second roadside machine is different from the section on the route from the first roadside machine in response to receiving the identifier of the first roadside machine from the other vehicle-mounted machine. The sensor data collection method according to claim 6, wherein the other sensor data is received from the other vehicle-mounted device.   The second roadside machine has at least the sensor data from the vehicle-mounted device and the other sensor data from the other vehicle-mounted device, and the same roadmap from the first roadside device to the second roadside device. The sensor data collection method according to claim 9, wherein the sensor data of the route is used. A roadside machine included in the sensor data collection system,
In response to receiving the identifier of the first roadside machine from the in-vehicle device, an acquisition section determining unit that determines a section on the route from the first roadside machine to the roadside machine,
A roadside machine comprising a road-to-vehicle transmission / reception unit that transmits the determined designation of the section to the in-vehicle device and receives sensor data of the section from the in-vehicle device.   12. The roadside machine according to claim 11, wherein the designation of the section is designation of an estimated time when the in-vehicle device passes the section.   With reference to position information obtained by measuring measurement data included in the sensor data, when the position information is not included in the section, the sensor data is set as sensor data in another section different from the section. The roadside machine according to claim 12. The acquisition section determination unit determines the other section different from the section on the route in response to receiving the identifier of the first roadside device from another onboard device different from the onboard device,
The said road-to-vehicle transmission / reception part transmits designation | designated of the said other area to the said other vehicle equipment, and receives the said other sensor data from the said other vehicle equipment. Roadside machine.   At least the sensor data from the vehicle-mounted device and the other sensor data from the other vehicle-mounted device are sensor data of the same route from the first roadside device to the roadside device. The roadside machine according to claim 14. A roadside machine program to be executed by a roadside machine included in the sensor data collection system,
In response to receiving the identifier of the first roadside device from the in-vehicle device, the section on the route from the first roadside device to the roadside device is determined,
Send the specified designation of the section to the in-vehicle device,
A roadside machine program for executing processing for receiving sensor data of the section from the in-vehicle device.   The roadside machine program according to claim 16, wherein the designation of the section causes the in-vehicle device to execute processing that is designation of an estimated time when the vehicle has passed through the section.   If the position information is not included in the section with reference to the position information obtained by measuring the measurement data included in the sensor data, the sensor data is processed as sensor data in another section different from the section. The roadside machine program of Claim 17 for making it run. In response to receiving the identifier of the first roadside device from another onboard device different from the onboard device, determine the other section different from the section on the route,
Send the designation of the determined other section to the other vehicle-mounted device,
The roadside machine program according to claim 16 for performing processing which receives said other sensor data from said other vehicle equipment.   In order to execute a process in which at least the sensor data from the in-vehicle device and the other sensor data from the other in-vehicle device are used as sensor data of the same route from the first roadside device to the roadside device. The roadside machine program according to claim 19.

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