Location information detection device

Abstract

To provide a positional information detection device capable of detecting accurate positional information.SOLUTION: A positional information detection device 5 includes a receiving unit 51 for receiving a plurality of pieces of data in which a plurality of node coordinates arranged corresponding to right and left rails with constant intervals are related to the positional information, a generation unit 521 for generating an edge image by using an input image from an imaging device arranged on a vehicle, a rail identification unit 522 for identifying data including second rail point sequence information which is the plurality of node coordinates overlapping most with the positions of edges included in the edge image, and a vehicle position acquisition unit 523 for acquiring second positional information based on the identified data.SELECTED DRAWING: Figure 4

Description

Technical Field

[0001] Embodiments of the present invention relate to a position information detection device.

Background Art

[0002] A method is known in which image features (such as edges) of left and right rails are extracted from an image captured by a camera mounted in front of a vehicle (particularly, a train), and the rails in the traveling direction are detected. However, with this method, it may be impossible to extract image features depending on the shape of the rails (such as curves or branches), weather, time of day, etc., and it has been difficult to achieve stable performance.

[0003] In addition, a method is known in which rail information is stored in advance in a map database, and left and right rail information is obtained by linking the map database with GNSS (Global Navigation Satellite System) position information.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] While the method of linking a map database with GNSS position information can achieve stable performance, it cannot detect rails taking into account errors in GNSS position information, and position correction of the vehicle may be required in places where the position accuracy of the vehicle is questioned.

[0006] Embodiments of the present invention have been made in view of the above circumstances, and an object thereof is to provide a position information detection device capable of detecting accurate position information.

Means for Solving the Problems

[0007] A position information detection device according to one embodiment includes: a receiving unit that receives multiple data sets associated with position information, where multiple node coordinates are arranged at regular intervals to correspond to the left and right rails; a generating unit that generates an edge image using an input image from an imaging device placed on the vehicle; a rail identification unit that identifies the data including second rail point sequence information, which is a plurality of node coordinates that most overlap with the edge positions included in the edge image; and a vehicle position acquisition unit that acquires second position information based on the identified data. The generation unit generates edge images by extracting edge positions near the left and right rails from the input image. The rail identification unit uses the degree of overlap between the edge positions of the edge images and rail point sequence information, which is composed of multiple node coordinates based on the image coordinate system of imaging devices arranged at regular intervals, as an evaluation index to identify data including second rail point sequence information, which is the multiple node coordinates with the greatest overlap. The vehicle position acquisition unit acquires second position information based on this identified data. [Brief explanation of the drawing]

[0008] [Figure 1] Figure 1 is a schematic diagram showing an example of the overall configuration of a location information detection system including a location information detection device according to one embodiment. [Figure 2] Figure 2 is a block diagram showing an example of the configuration of a central device according to one embodiment. [Figure 3] Figure 3 illustrates an example of left and right rail node information included in a map database. [Figure 4] Figure 4 is a block diagram showing an example configuration of a vehicle equipped with a location information detection device according to one embodiment. [Figure 5] Figure 5 illustrates an example of edge positions near the left and right rails included in the edge image and multiple node coordinates included in the left and right rail point sequence information. [Figure 6] Figure 6 is a flowchart illustrating an example of the position detection processing operation of a position information detection device according to one embodiment. [Figure 7] Figure 7 is a flowchart illustrating an example of the position detection processing operation of a position information detection device according to one embodiment. [Figure 8] Figure 8 is a flowchart illustrating an example of the position detection processing operation of a position information detection device according to one embodiment. [Modes for carrying out the invention]

[0009] The location information detection device according to the embodiment will be described in detail below with reference to the drawings. Note that the scale of each part in the drawings used in the description of the embodiment below has been changed as appropriate. Also, in the drawings used in the description of the embodiment below, some components may be omitted for illustrative purposes.

[0010] Figure 1 is a schematic diagram showing an example of the overall configuration of a location information detection system including a location information detection device according to one embodiment. The location information detection system shown in Figure 1 comprises a vehicle 1 and a central device 2. Vehicle 1 is, for example, a vehicle included in a train that runs on rails according to a predetermined schedule. Note that if a train has multiple vehicles, not all vehicles need to have the functions described below.

[0011] Vehicle 1 is connected to the central device 2 and satellite 3 via networks. Vehicle 1 is, for example, the vehicle located at the front of a train in the direction of travel, and is equipped with an antenna (not shown) that receives radio waves from satellite 3. For example, the antenna is installed on the roof approximately 3m behind the frontmost position of the vehicle that is designed to be at the very front of the train. The position information of vehicle 1 is based on the position where the antenna is installed.

[0012] The central unit 2 is configured to communicate with the vehicles 1 via a network and, for example, manages the operating status of multiple vehicles 1. Figure 2 is a block diagram showing an example of the configuration of the central device 2 according to one embodiment. The central device 2 of this embodiment includes a receiving unit 21, a control unit 22, an input unit 23, an output unit 24, a storage unit 25, a transmitting unit 26, and a bus communication line BL1.

[0013] Bus communication line BL1 is connected to each of the components included in the central device 2. The control unit 22 can send and receive data to and from other components included in the central device 2 via bus communication line BL1.

[0014] The receiving unit 21 receives landmark information and information regarding the error corrected by the vehicle 1 (hereinafter referred to as error information) from the vehicle 1. The error information includes, for example, that there is an error in the current position information of the vehicle 1 using GNSS position information (hereinafter referred to as first position information), that the error has been corrected with the position information of the vehicle 1 obtained using the input image from the imaging device 4 described later (hereinafter referred to as second position information), that the error has been corrected with the position information of the vehicle 1 obtained using landmark information (hereinafter referred to as third position information), the landmark information included in the corrected input image, the correction area estimated from the first position information, and the rail point sequence information of the correction area obtainable from the data of the map database, and includes at least one of them. The information included in the error information is not limited to the above. Details of the landmark information, the second position information, and the third position information will be described later.

[0015] The control unit 22 includes at least one processor such as a CPU (Central Process Unit), MPU (micro processing unit), GPU (Graphics Processing Unit), or FPGA (field-programmable gate array). The control unit 22 can realize various functions of the central device 2 based on programs such as system software, application software, or firmware stored in the auxiliary storage unit 252.

[0016] The control unit 22 compares the landmark information fed back from the vehicle 1 with the landmark information included in the data of the map database stored in the storage unit 25, referring to the position information of the vehicle 1. When the landmark existing in the landmark candidate area included in the fed-back landmark information does not match the landmark existing in the landmark candidate area included in the landmark information of the map database, the control unit 22 corrects the information as necessary and outputs it to the output unit 24.

[0017] The input unit 23 may include user interfaces such as a mouse and a keyboard, as well as a microphone, a touch panel, a camera, and various sensors. The input unit 23 transmits the information acquired by the user's operation to the control unit 22 via the bus communication line BL1.

[0018] The output unit 24 may include display means such as a monitor, and audio output means such as a speaker. Note that the output unit 24 may be configured to be connected to the outside of the computer. The output unit 24 displays the information output by the control unit 22 on a monitor or the like as alarm information or outputs it using audio output means such as a speaker.

[0019] The storage unit 25 includes, for example, a main storage unit 251 and an auxiliary storage unit 252. The main storage unit 251 may include, for example, a ROM (read-only memory) and a RAM (random-access memory). The ROM is a non-volatile memory used exclusively for reading data, and can store data and various setting values used by the control unit 22 to perform various processes. Also, the RAM can be used as a so-called work area for temporarily storing data while the control unit 22 performs various processes. The main storage unit 251 of the present embodiment is, for example, a RAM and is used as a memory.

[0020] The main storage unit 251 can temporarily store data in the map database, position information priority settings, error information, and the like. The auxiliary storage unit 252 is a non-temporary computer-readable storage medium of a computer centered on the control unit 22. The auxiliary storage unit 252 is, for example, an EEPROM (registered trademark) (electric erasable programmable read-only memory), a HDD (hard disk drive), or a SSD (solid state drive).

[0021] The auxiliary storage unit 252 can store data used by the control unit 22 for various processing, data generated by processing in the control unit 22, or various setting values. For example, the auxiliary storage unit 252 is a memory for storing various information, and can store timetable (schedule) information, map database data, location information priority settings, and error information. A specific explanation of location information priority settings will be given later. Timetable information includes, for example, information about the stations where the train stops, the time of arrival at each station, and the time of departure from each station, along the route of train 1, thus including information about the train's location and time.

[0022] The map database contains multiple sets of data associated with and stored to correspond to the location information of vehicle 1. For example, the map database contains multiple sets of data such as location information (latitude, longitude, elevation), terrain topography, rail shape, location features, landmark information (number, size, coordinates, type), left rail node information (number, coordinates), and right rail node information (number, coordinates). In the map database, multiple data sets are associated with identifiers (e.g., line numbers) assigned in order of the vehicle's location information. However, the data contained in the map database is not limited to the above. The data in the map database is assumed to have been acquired or updated in advance by a dedicated vehicle.

[0023] Figure 3 illustrates an example of left and right rail node information included in a map database. The coordinates in the left and right rail node information included in the map database are the position coordinates of the rails in the image captured by the imaging device 4 when vehicle 1 is traveling at the location information (latitude, longitude, altitude). The node coordinates are calculated by setting the upper left corner of the input image from the imaging device 4 (upper left corner when facing the direction of travel of vehicle 1) as the reference 0 (origin), with the horizontal direction to the right of the reference being a positive value for the x-axis and the vertical direction downward from the reference being a positive value for the y-axis. The reference point and axis settings are assumed to be predetermined by the map database creator, etc. The same applies to the coordinates in the landmark information held in the map database.

[0024] The set of left rail node information (number, coordinates) and right rail node information (number, coordinates) contained in the map database data is called rail point sequence information. Rail point sequence information consists of the coordinates of multiple nodes placed at regular intervals and is associated with the position information (latitude, longitude, altitude) of vehicle 1. By connecting adjacent nodes (the ones with the shortest distance between node coordinates) in the rail point sequence information with straight lines, it is possible to reproduce a shape that is approximately the same as the rail. If the shape of the rail is a curve or a branch, it is possible to reproduce a shape that is approximately the same as the rail in the same way as above by making the distance between nodes as short as possible and creating a pseudo-curve.

[0025] The transmission unit 26 transmits the map database data to the vehicle 1 (the location information detection device 5 and the support control device 6 described later). The map database data in the central device 2 may consist of two map databases: master data and vehicle instruction data. The master data of the map database includes detailed map information for the entire driving route, and the vehicle instruction data of the map database includes information from at least a portion of the master data, including data for each vehicle's driving route in accordance with the timetable. The transmission unit 26 transmits at least the vehicle instruction data to the location information detection device 5 and the support control device 6 of the vehicle 1 in response to a request from the vehicle 1, or periodically.

[0026] Figure 4 is a block diagram showing an example configuration of a vehicle equipped with a location information detection device according to one embodiment. The vehicle 1 of this embodiment includes an imaging device 4, a location information detection device 5, a support control device 6, and a bus communication line BL2. The bus communication line BL2 is connected to each of the multiple components included in the vehicle 1. The control unit 52 included in the position information detection device 5 and the correction control unit 62 included in the support control device 6 can communicate data with the other components included in the vehicle 1 via the bus communication line BL2.

[0027] The imaging device 4 is, for example, a stereo camera. The imaging device 4 transmits the captured image as an input image to the location information detection device 5. The imaging device 4 may be configured to transmit an input image 30 times per second when the frame rate is 30 fps. The frequency at which the imaging device 4 sends an input image to the location information detection device 5 is not limited to the above and can be changed as appropriate depending on the frame rate of the imaging device 4 and the frequency of radio wave reception from satellite 3.

[0028] The support control device 6 comprises a receiving unit 61, a correction control unit 62, a storage unit 63, and a transmitting unit 64. The receiving unit 61 receives first position information from the antenna that receives radio waves from satellite 3. The receiving unit 61 has the function of receiving multiple data from the map database. The receiving unit 61 also receives second position information, third position information, rail point sequence information, and landmark information from the position information detection device 5.

[0029] The correction control unit 62 includes at least one processor such as a CPU (Central Process Unit), MPU (microprocessing unit), GPU (Graphics Processing Unit), or FPGA (field-programmable gate array). The correction control unit 62 can implement various functions of the support control device 6 based on programs such as system software, application software, or firmware stored in the auxiliary storage unit 632.

[0030] The correction control unit 62 compares the first position information with the second position information and performs processing according to the comparison result. More specifically, the correction control unit 62 detects the error between the first position information and the second position information, and if the error exceeds a predetermined threshold, it can refer to the position information priority setting and correct the error by using either the first or second position information as the current position information of vehicle 1.

[0031] Similarly, the correction control unit 62 compares the first position information with the third position information and performs processing according to the comparison result. The correction control unit 62 compares the second position information with the third position information and performs processing according to the comparison result. More specifically, the correction control unit 62 detects an error between the first position information and the third position information, and if the error exceeds a predetermined threshold, it can refer to the position information priority setting and correct the error by using either the first or third position information as the current position information of vehicle 1. Furthermore, the correction control unit 62 detects an error between the second position information and the third position information, and if the error exceeds a predetermined threshold, it can refer to the position information priority setting and correct the error by using either the second or third position information as the current position information of vehicle 1.

[0032] The memory unit 63 includes, for example, a main memory unit 531 and an auxiliary memory unit 532. The main memory unit 631 may include, for example, ROM (read-only memory) and RAM (random-access memory). ROM is a non-volatile memory used exclusively for reading data, and can store data and various setting values ​​used by the correction control unit 62 in performing various processes. RAM can be used as a so-called work area to temporarily store data when the correction control unit 62 performs various processes. In this embodiment, the main memory unit 631 is, for example, RAM and is used as memory.

[0033] The main memory unit 631 can temporarily store data from the map database, first position information, rail point sequence information, second position information, landmark information, third position information, position information priority setting, and information regarding errors corrected by the correction control unit 62 (error information).

[0034] The auxiliary storage unit 632 is a non-temporary computer-readable storage medium of the computer centered around the correction control unit 62. The auxiliary storage unit 632 is, for example, an EEPROM (electric erasable programmable read-only memory), an HDD (hard disk drive), or an SSD (solid state drive).

[0035] The auxiliary storage unit 632 can store data used by the correction control unit 62 in performing various processes, data generated by processing in the correction control unit 62, or various setting values. For example, the auxiliary storage unit 632 is a memory for storing various information, and can store data from the map database, first position information, rail point sequence information, second position information, landmark information, third position information, position information priority settings, and information regarding errors corrected by the correction control unit 62 (error information). The transmitting unit 64 transmits landmark information and error information to the central device 2. The transmitting unit 64 also transmits the error information to the location information detection device 5.

[0036] The location information detection device 5 of this embodiment comprises a receiving unit 51, a control unit 52, a storage unit 53, and a transmitting unit 54. The location information detection device 5 may include a processor that executes a program to realize various functions described later, and a memory that stores the program. The processor is typically a CPU (Central Processing Unit) and / or a GPU (Graphics Processing Unit), but may also be a microcontroller, FPGA (Field Programmable Gate Array), or DSP (Digital Signal Processor). The memory stores the program executed by the processor to realize the operation of the location information detection device 5, and also temporarily stores data used by the processor. The program may be recorded on a recording medium readable by the location information detection device 5. In that case, the processor can realize various functions by executing the program read from the recording medium.

[0037] The receiving unit 51 receives first position information from an antenna that receives radio waves from satellite 3. The receiving unit 51 is equipped with the function to receive multiple timetable information and map database data from the central device 2. For example, the receiving unit 51 can receive a day's worth of timetable and map database data from the central device 2 all at once before starting the day's journey.

[0038] The receiving unit 51 can receive map database data according to the operating status. The map database data received by the receiving unit 51 may be configured such that, for example, when vehicle 1 moves from station A to station B, it receives data from station A to station B from the central device 2, and then when it moves from station B to station C, it receives data from station B to station C from the central device 2. Alternatively, for example, the map database data received by the receiving unit 51 from the central device 2 may only receive data associated with location information of a few meters before and after the current location of vehicle 1, and update this data in real time.

[0039] The receiving unit 51 further receives input images from the imaging device 4. The imaging device 4 and the receiving unit 51 may be connected via a wired connection or via a wireless connection. The receiving unit 51 can communicate with the imaging device 4 based on communication standards such as the Internet, Ethernet (registered trademark), wireless LAN (Wi-Fi (registered trademark), Bluetooth (registered trademark), etc.).

[0040] The control unit 52 includes at least one processor, such as a CPU (Central Process Unit), MPU (microprocessing unit), GPU (Graphics Processing Unit), or FPGA (field-programmable gate array). The control unit 52 can implement various functions of the location information detection device 5 based on programs such as system software, application software, or firmware stored in the auxiliary storage unit 532. The control unit 52 includes a generation unit 521, a rail identification unit 522, a vehicle position acquisition unit 523, and a landmark detection unit 524.

[0041] The landmark detection unit 524 detects objects in the input image from the imaging device 4 that are real estate and have distinctive features such as shape, brightness, color, and pattern (hereinafter referred to as landmarks). Landmark information is pre-stored in the map database and is associated with location information and rail point sequence information. The landmark detection unit 524 refers to the landmark information associated with the first location information, and after recognizing the existence of a landmark, displays a candidate landmark area. The data contained in the landmark information includes, for example, the number of landmarks, size (length and width), coordinates (x, y), and landmark type (such as those attached to overhead line poles or buildings). The landmark detection unit 524 sends the detected landmark information to the rail identification unit 522 and the vehicle position acquisition unit 523.

[0042] Figure 5 illustrates an example of edge positions near the left and right rails included in the edge image and multiple node coordinates included in the left and right rail point sequence information. The generation unit 521 detects areas with significant brightness changes from the input image of the imaging device 4 received by the receiving unit 51 and generates an edge image. The edge image generation process is performed using a generally known method.

[0043] The rail identification unit 522 compares the edge positions near the left and right rails included in the edge image generated by the generation unit 521 with multiple node coordinates included in the left and right rail point sequence information. The rail identification unit 522 identifies the second rail point sequence information, which consists of multiple node coordinates that have the largest overlap with the edge positions, and the data including said second rail point sequence information. Furthermore, the rail identification unit 522 can identify the first rail point sequence information using data from a map database associated with the first position information received by the receiving unit 51.

[0044] The rail identification unit 522 identifies the third rail point sequence information from the data associated with the landmark information detected by the landmark detection unit 524. The vehicle position acquisition unit 523 acquires position information included in the data identified by the rail identification unit 522. This position information acquired by the vehicle position acquisition unit 523 becomes the second position information. The vehicle position acquisition unit 523 identifies third position information from data associated with landmark information detected by the landmark detection unit 524.

[0045] The vehicle position acquisition unit 523 compares the first to third position information, and if there are errors in the first, second, and third position information, it selects the position information according to the position information priority setting, which has been set in advance based on the rail shape and other factors. Details of the above process will be described later. In addition, the process of selecting the position information of vehicle 1 may not be performed by the vehicle position acquisition unit 523, but rather the support control device 6 may correct the error, and the position information detection device 5 may perform the process based on the corrected result. Furthermore, the vehicle position acquisition unit 523 may be configured to output the result of comparing the first rail point sequence information and the second rail point sequence information.

[0046] The location information priority setting based on the rail shape described above is just one example and is not limited to this. The location information priority setting can be determined using the reliability of each of the first, second, and third location information as one of the indicators. In this embodiment, the positioning methods using GNSS include standalone positioning, relative positioning, and autonomous position detection. Standalone positioning involves receiving information such as the satellite's position and time transmitted from a GNSS satellite with a single antenna, measuring the time it takes for the radio waves to reach the receiver after they are transmitted from the satellite, and converting this into distance. The position of vehicle 1 is determined by simultaneously knowing the distances from four or more satellites to the observation point, using a GNSS satellite whose position is known as a moving reference point.

[0047] Relative positioning involves using two or more receivers to simultaneously observe four or more identical GNSS satellites. Using the position of the GNSS satellite as a reference, the relative positional relationship between two points is calculated by measuring the time difference between when the radio signals from the GNSS satellite reach each receiver. Autonomous position detection calculates position information using factors such as wheel rotation speed and current vehicle speed, for example, when estimating the vehicle's position in areas where radio waves from GNSS satellites cannot reach.

[0048] In terms of location reliability, relative positioning offers the highest reliability, followed by standalone positioning, and finally autonomous position detection. Relative positioning has a location error of approximately 0.5m or less, standalone positioning has an error of approximately 1-2m or less, and autonomous position detection is even more reliable. Therefore, location information priority settings are configured according to the positioning method. These location information priority settings are predetermined by the administrator or user of the location detection system.

[0049] Let's explain a specific example of the above location information priority setting. If vehicle 1 is traveling at 108 km / h (30 m / s) and the frame rate of imaging device 4 is 30 fps, the distance traveled in one frame will be approximately 1 m. If vehicle 1 is traveling at 36 km / h (10 m / s) and the frame rate of imaging device 4 is 30 fps, the distance traveled in one frame will be approximately 0.3 m. As such, the distance traveled in one frame changes depending on the speed of vehicle 1, and therefore the amount of deviation in vehicle 1's location information also changes. For this reason, the location information priority setting will be set so that, for example, the first location information is prioritized if relative speed is used, and the second or third location information is prioritized if standalone positioning or autonomous position detection is used.

[0050] Furthermore, location information priority settings can also be determined based on the shape of the rails. The shape of the rails can be determined by narrowing down the area from the first location information. For example, if the shape of the rails is straight, the rail point sequence information may be similar. Therefore, the possibility of not being able to obtain correct location information increases, and the priority of the second location information decreases. Similarly, if the shape of the rails is curved, the rail point sequence information may be similar in places where the curvature does not change, so the priority of the second location information decreases.

[0051] On the other hand, when the rail shape is that of a track junction, the rail point sequence information becomes distinctive and less likely to be similar to other rails. Therefore, the second position information is more accurate than the first position information, and the priority of the second position information increases.

[0052] Furthermore, in areas where radio waves cannot reach, such as tunnels, the first position information is determined by autonomous position detection, but it is set according to the shape of the rails, as described above. The third position information is more reliable than the first and second position information and is set to have the highest priority regardless of the shape of the rails.

[0053] The memory unit 53 includes, for example, a main memory unit 531 and an auxiliary memory unit 532. The main memory unit 531 may include, for example, ROM (read-only memory) and RAM (random-access memory). ROM is a non-volatile memory used exclusively for reading data, and can store data and various setting values ​​used by the control unit 52 in performing various processes. RAM can be used as a so-called work area to temporarily store data when the control unit 52 performs various processes. In this embodiment, the main memory unit 531 is, for example, RAM and is used as memory.

[0054] The main memory unit 531 can temporarily store data from the map database, first location information, input images from the imaging device 4, edge images, rail point sequence information, second location information, landmark information, third location information, and location information priority settings.

[0055] The auxiliary storage unit 532 is a non-temporary computer-readable storage medium for the computer centered around the control unit 52. The auxiliary storage unit 532 is, for example, an EEPROM (electric erasable programmable read-only memory), an HDD (hard disk drive), or an SSD (solid state drive).

[0056] The auxiliary storage unit 532 can store data used by the control unit 52 in performing various processes, data generated by processing in the control unit 52, or various setting values. For example, the auxiliary storage unit 532 is a memory for storing various information and can store data from a map database, first position information, input images from the imaging device 4, edge images, rail point sequence information, second position information, landmark information, third position information, and position information priority settings.

[0057] The transmitting unit 54 transmits second position information, third position information, rail point sequence information, and landmark information to the support control device 6. The transmitting unit 54 can communicate based on communication standards such as the Internet, Ethernet (registered trademark), wireless LAN (Wi-Fi (registered trademark), Bluetooth (registered trademark), etc.).

[0058] Figures 6 to 8 are flowcharts illustrating an example of the position detection processing operation of a position information detection device according to one embodiment. The following describes an example of a procedure for acquiring multiple location information points for vehicle 1 using the location information detection device 5 and determining the location information of vehicle 1 according to the location information priority setting. Note that the processing content in the following operation description is just an example, and various processes that can achieve similar effects can be used as appropriate.

[0059] The location information detection device 5 receives, for example, vehicle instruction data (hereinafter referred to as "data") from the central device 2 in a map database for a specific section using the receiving unit 51. The location information detection device 5 stores the data in the storage unit 53, and the control unit 52 retrieves the data from the storage unit 53 (step 1). Since the vehicle 1 in this embodiment is a vehicle that travels along a predetermined route according to the timetable, the time it takes to travel between predetermined stations is predetermined, and the data is acquired based on that time.

[0060] The receiving unit 51 acquires first position information from the antenna (step 2). Note that the order of processing steps 1 and 2 may be reversed; for example, step 2 may be performed, and the central device 2 may transmit data about the area by referring to the first position information. The control unit 52 acquires input images from the imaging device 4 according to the number of frames (step 3). The input images are assumed to be acquired by the control unit 52 in real time.

[0061] The generation unit 521 performs edge processing on the acquired input image to generate an edge image from the input image. Note that the generation unit 521 does not need to perform edge processing on all input images and generate an edge image; for example, it may generate an edge image from at least one of the three input image frames.

[0062] The rail identification unit 522 compares the edge image with multiple node coordinates (step 4). The node coordinates to be compared are selected, for example, based on first position information. The rail identification unit 522 takes into account the error of the first position information and selects node coordinates from data associated with position information within a few meters before and after the first position information. It may also be configured to compare with all node coordinates included in the data.

[0063] The rail identification unit 522 identifies data containing multiple node coordinates (rail point sequence information) that most overlap with the edge positions included in the edge image, based on the comparison results from step 4 (step 5). The vehicle position acquisition unit 523 acquires second position information based on the identified data (step 6).

[0064] The landmark detection unit 524 acquires information about landmarks from data including first position information (step 7). The information about landmarks includes the number of landmarks, the size of the landmarks, the coordinates of the landmarks, and the type of landmarks. If the landmark detection unit 524 determines from the above landmark information that there are landmarks in the input image (step 7, YES), it displays a candidate landmark area and detects landmarks that are within or near that area (step 8).

[0065] When the landmark detection unit 524 detects a landmark within or near the landmark candidate area, it calculates the error between the landmark candidate area and the landmark detection area. Regardless of whether there is an error, the landmark detection unit 524 identifies data containing landmark information from the landmark coordinates of the landmark detection area and obtains third position information based on the identified data (step 9).

[0066] Furthermore, the processes of acquiring the first location information in step 2, acquiring the second location information in steps 3 through 6, and acquiring the third location information in steps 7 through 9 are not limited to the transition shown in Figure 6. For example, steps 2, 3 through 6, and 7 through 9 may be processed in parallel. When the landmark detection unit 524 acquires the third position information in step 9, the control unit 52 maintains or updates the current position information of vehicle 1 according to the position information priority setting.

[0067] The control unit 52 compares the first position information and the second position information based on the position information priority setting and determines the current position information of vehicle 1 (step 10). If the control unit 52 determines the first location information to be the current location information of vehicle 1 based on the location information priority setting (step 10, NO), it maintains the current vehicle location information as the first location information (step 11). After processing in step 11, the control unit 52 compares the first position information and the third position information again based on the position information priority setting to determine the current position information of vehicle 1 (step 13).

[0068] If the control unit 52 determines the first location information to be the current location information of vehicle 1 based on the location information priority setting (step 13, NO), it maintains the current vehicle location information as the first location information (step 14). If the control unit 52 determines that the third location information is the current location information of vehicle 1 based on the location information priority setting (step 13, YES), it updates the current vehicle location information to the third location information (step 15).

[0069] If the control unit 52 determines that the second location information is the current location information of vehicle 1 based on the location information priority setting (step 10, YES), it updates the current vehicle location information to the second location information (step 12). After processing in step 12, the control unit 52 compares the second position information and the third position information again based on the position information priority setting to determine the current position information of vehicle 1 (step 16).

[0070] If the control unit 52 determines that the second location information is the current location information of vehicle 1 based on the location information priority setting (step 16, NO), it maintains the current vehicle location information as the second location information (step 17). If the control unit 52 determines that the third location information is the current location information of vehicle 1 based on the location information priority setting (step 16, YES), it updates the current vehicle location information to the third location information (step 18). The control unit 52 causes the transmission unit 54 to transmit data including the current location information of vehicle 1 to the support control device 6 (step 19), and then terminates the process.

[0071] If the landmark detection unit 524 determines from the landmark information above that there are no landmarks in the input image (step 7, NO), it proceeds to the process in step 20. The control unit 52 compares the first position information and the second position information based on the position information priority setting and determines the current position information of vehicle 1 (step 20). If the control unit 52 determines the first position information to be the current position information of vehicle 1 based on the position information priority setting (step 20, NO), it maintains the current vehicle position information as the first position information (step 21).

[0072] If the control unit 52 determines that the second location information is the current location information of vehicle 1 based on the location information priority setting (step 20, YES), it updates the current vehicle location information to the second location information (step 22). The control unit 52 causes the transmission unit 54 to transmit data including the current location information of vehicle 1 to the support control device 6 (step 23), and then terminates the process.

[0073] In this embodiment, the current location information of vehicle 1 was based on the first location information, but this could also be the second or third location information. When the current location information of vehicle 1 is updated, the flowchart process transitions based on that updated location information.

[0074] Here, we consider the case in the flowchart above where area determination is performed based on the first location information, and location information other than the first location information is selected as the current location information due to location information priority setting. If the data number in the map database for the first rail point sequence information and the data number in the map database for the rail point sequence information associated with the selected location information exceed a predetermined threshold, the vehicle position acquisition unit 523 is configured to select the location information with the next highest location information priority setting after the currently selected location information.

[0075] The predetermined thresholds are set in advance by the administrator or user of the location information detection system. Furthermore, the criteria for area determination are not limited to the first location information, but may also include the second or third location information.

[0076] With the position information detection device 5 of this embodiment, by acquiring the current position information of vehicle 1, the position information detection device 5 can obtain accurate information about the rail on which vehicle 1 is currently traveling from the rail point sequence information of the data including the position information. By acquiring the above rail information, vehicle 1 can, for example, set a detection target area of ​​several tens of centimeters around the rail and detect obstacles in front of it. In other words, according to this embodiment, it is possible to provide a location information detection device capable of detecting accurate location information.

[0077] While several embodiments of the present invention have been described, these embodiments are presented as examples only and are not intended to limit the scope of the invention. These novel embodiments can be carried out in a variety of other forms, and various omissions, substitutions, and modifications can be made without departing from the spirit of the invention. These embodiments and their variations are included in the scope and spirit of the invention, as well as in the claims of the invention and its equivalents. The original claims of this application are included below. [C1] A receiving unit that receives multiple data sets associated with positional information, where multiple node coordinates are arranged at regular intervals to correspond to the left and right rails, A generation unit that generates an edge image using an input image from an imaging device placed on the vehicle, and a rail identification unit that identifies the data including a second rail point sequence information which is a plurality of node coordinates that most overlap with the position of the edge included in the edge image, A vehicle position acquisition unit that acquires second position information based on the identified data, A location information detection device equipped with the following features. [C2] The device includes a detection unit that detects landmarks included in the input image from the aforementioned imaging device, The data includes information about the landmark associated with the location information, The rail identification unit identifies the data including the landmark information detected by the detection unit, The vehicle position acquisition unit acquires third position information based on the identified data. Location information detection device as described in C1. [C3] The receiving unit receives the first position information of the vehicle measured by GNSS, The vehicle position acquisition unit selects the current vehicle position information from the first position information, the second position information, and the third position information according to a preset position information priority setting. Location information detection device as described in C2. [C4] The receiving unit receives the first position information of the vehicle measured by GNSS, The rail identification unit identifies the first rail point sequence information from the data including the first position information, The vehicle position acquisition unit outputs the result of comparing the first rail point sequence information and the second rail point sequence information. Location information detection device as described in C1. [Explanation of symbols]

[0078] 1...Vehicle, 2...Central unit, 3...Satellite, 4...Imaging device, 5...Position information detection device, 6...Support control device, 21...Receiver, 22...Control unit, 23...Input unit, 24...Output unit, 25...Storage unit, 251...Main storage unit, 252...Auxiliary storage unit, 26...Transmitter, 51...Receiver, 52...Control unit, 521...Generator, 522...Rail identification unit, 523...Vehicle position acquisition unit, 524...Landmark detection unit, 53...Storage unit, 531...Main storage unit, 532...Auxiliary storage unit, 54...Transmitter, 61...Receiver, 62...Correction control unit, 63...Storage unit, 631...Main storage unit, 632...Auxiliary storage unit, 64...Transmitter

Claims

1. A receiving unit that receives multiple data sets associated with positional information, where multiple node coordinates are arranged at regular intervals to correspond to the left and right rails, A generation unit that generates edge images using input images from an imaging device installed in the vehicle, A rail identification unit identifies the data which includes a second rail point sequence information, which is a plurality of node coordinates that most overlap with the position of the edge included in the edge image, A vehicle position acquisition unit that acquires second position information based on the identified data, Equipped with, The generation unit generates edge images by extracting edge positions near the left and right rails from the input image. The rail identification unit uses the degree of overlap between rail point sequence information, which is composed of multiple node coordinates based on the image coordinate system of imaging devices arranged at regular intervals, and the edge positions of the edge image as an evaluation index, to identify the data including the second rail point sequence information, which is the multiple node coordinates with the greatest overlap. The aforementioned vehicle position acquisition unit is a position information detection device that acquires second position information based on the specified data.

2. The device includes a detection unit that detects landmarks included in the input image from the aforementioned imaging device, The data includes information about the landmark associated with the location information, The rail identification unit identifies the data including the landmark information detected by the detection unit, The vehicle position acquisition unit acquires third position information based on the identified data. The location information detection device according to claim 1.

3. The receiving unit receives the first position information of the vehicle measured by GNSS, The vehicle position acquisition unit selects the current vehicle position information from the first position information, the second position information, and the third position information according to a preset position information priority setting. The location information detection device according to claim 2.

4. The receiving unit receives the first position information of the vehicle measured by GNSS, The rail identification unit identifies the first rail point sequence information from the data including the first position information, The vehicle position acquisition unit outputs the result of comparing the first rail point sequence information and the second rail point sequence information. The location information detection device according to claim 1.

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