Marker system and magnetic marker detection method

Abstract

A marker system (1) includes a plurality of magnetic markers (10), arranged on a road surface, for driving assistance control of a vehicle (5) including automatic traveling control. A wireless tag is provided to a portion (10A) of the magnetic markers (10). Since a mark (1M) for distinguishing between the portion (10A) of the magnetic markers provided with the wireless tag and other magnetic markers (10B) not provided with a wireless tag is provided, a detected magnetic marker (10) can be highly accurately associated with a wireless tag of a transmission source of a tag radio wave.

Description

[Technical Field]

[0001] The present invention relates to a marker system including magnetic markers arranged on a road, and a method for detecting the magnetic markers. [Background technology]

[0002] Conventionally, magnetic markers that are placed on roads have been known (see, for example, Patent Document 1). Magnetic markers can be detected, for example, by using a magnetic sensor provided in a vehicle. For example, by using magnetic markers placed along lanes, various driving assistance functions such as automatic steering control and lane departure warning can be realized, as well as autonomous driving.

[0003] Because a magnetic marker alone cannot provide a sufficient amount of information to a vehicle, there have been proposals for magnetic markers that hold wireless tags that can provide information via wireless communication (see, for example, Patent Document 2). For example, by combining a wireless tag that provides location information with a magnetic marker, the vehicle's own position can be identified with high accuracy when the vehicle detects the magnetic marker. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Publication No. 2018-010356 [Patent Document 2] Japanese Patent Application Publication No. 2019-215636 Summary of the Invention [Problem to be solved by the invention]

[0005] Generally, the range of the tag radio waves transmitted by a wireless tag is much wider than the magnetic field that a magnetic marker exerts on its surroundings. Therefore, when a vehicle detects a magnetic marker while receiving tag radio waves, it is difficult to determine whether the wireless tag that transmitted the received tag radio waves is attached to the detected magnetic marker.

[0006] The present invention has been made in consideration of the above-mentioned problems of the conventional art, and aims to provide a marker system and a detection method in which, in a marker system in which wireless tags are attached to some of the magnetic markers placed on the road, when a vehicle detects one of the magnetic markers while receiving tag radio waves, it can reliably determine whether the tag radio waves being received are from the wireless tag attached to the detected magnetic marker. [Means for solving the problem]

[0007] One aspect of the present invention is a marker system including a plurality of magnetic markers arranged on a road surface for vehicle driving assistance control, including automatic driving control, comprising: a wireless tag capable of outputting information by wireless communication is attached to some of the magnetic markers, The marker system includes a sign for distinguishing the part of the magnetic markers to which the wireless tag is attached from the other magnetic markers excluding the part of the magnetic markers among the plurality of magnetic markers.

[0008] One aspect of the present invention is a method for detecting magnetic markers arranged on a road surface for vehicle driving assistance control, including automatic driving control, comprising: A wireless tag capable of outputting information by wireless communication is attached to some of the magnetic markers among a plurality of magnetic markers arranged on a road surface, magnetically detecting the magnetic marker; A process of acquiring information output by the wireless tag attached to the magnetic marker; and detecting a sign provided to distinguish the part of the magnetic markers to which the wireless tag is attached from the other magnetic markers among the plurality of magnetic markers excluding the part of the magnetic markers, The magnetic marker detection method includes detecting the magnetic marker and, when the magnetic marker and the sign are detected, associating the information obtained from the wireless tag with the detected magnetic marker. [Effects of the Invention]

[0009] In the present invention, the sign is provided to distinguish the part of the magnetic markers to which the wireless tag is attached from the other magnetic markers. By using this sign, it is possible to identify the part of the magnetic markers to which the wireless tag is attached. When the vehicle detects one of the magnetic markers while receiving radio waves from the wireless tag, the sign can be used to determine with high reliability whether the wireless tag that is the source of the radio waves being received is attached to the detected magnetic marker.

[0010] Thus, according to the present invention, in a marker system in which the wireless tag is attached to a portion of the magnetic marker installed on a road, it is possible to identify with high reliability the magnetic marker corresponding to the wireless tag that is the source of the radio waves. [Brief explanation of the drawings]

[0011] [Figure 1] FIG. 2 is a diagram showing a magnetic marker in the first embodiment. [Figure 2] FIG. 2 is an explanatory diagram showing a vehicle traveling on a lane on which magnetic markers are provided in the first embodiment. [Figure 3] FIG. 2 is a block diagram showing the electrical configuration of the vehicle in the first embodiment. [Figure 4] 4 is a flowchart showing a process flow in which the control unit outputs the vehicle position in the first embodiment. [Figure 5] FIG. 10 is an explanatory diagram of a second process in the first embodiment. [Figure 6] FIG. 2 is an explanatory diagram showing a vehicle traveling on a multi-lane road in the first embodiment. [Figure 7] FIG. 10 is an explanatory diagram showing another mark of the tagged marker in the first embodiment. [Figure 8] FIG. 10 is an explanatory diagram of other tagged markers and untagged markers in the first embodiment. [Figure 9] FIG. 10 is an explanatory diagram of other tagged markers and untagged markers in the first embodiment. [Figure 10] FIG. 10 is an explanatory diagram of another tagged marker in the first embodiment. [Figure 11]FIG. 10 is an explanatory diagram showing another mark of the tagged marker in the first embodiment. [Figure 12] FIG. 10 is an explanatory diagram of a label of a tagged marker in the second embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0012] The embodiments of the present invention will be specifically described using the following examples. Example 1 This example relates to a marker system 1 including a plurality of magnetic markers 10 arranged on a road surface for vehicle driving assistance control, including automatic driving control. The details of this example will be described with reference to FIGS.

[0013] The magnetic marker 10 (Figure 1) consists of a flat, circular magnet sheet 10S with a diameter of 100 mm and a thickness of 2 mm. The magnet sheet 10S is an isotropic ferrite rubber magnet with a maximum energy product (BHmax) of approximately 6.4 kJ / m3. The magnetic marker 10 can be adhesively bonded to the road surface, for example. As an adhesive, for example, molten or softened asphalt can be used. One surface of the magnetic marker 10 is a north pole, and the other surface is a south pole. The magnetic polarity that can be detected by the vehicle 5 changes depending on which surface of the magnetic marker 10 faces the road surface. The magnetic polarity that can be detected by the vehicle 5 is referred to as the magnetic polarity of the magnetic marker 10.

[0014] In the marker system 1, RFID tags (wireless tags) 12 are attached to some of the magnetic markers 10. The RFID tags 12 are sheet-shaped and are laminated on the surface of the magnetic marker 10. In particular, in this example, the RFID tags 12 are laminated on the surface of the north pole of the magnetic marker 10. In the following description, the magnetic markers 10 to which the RFID tags 12 are attached will be referred to as tagged markers 10A (see FIG. 2), and the other magnetic markers 10 to which the RFID tags 12 are not attached will be referred to as tagless markers 10B.

[0015] The RFID tag 12 (Fig. 1) is an electronic component that operates in response to an external power supply and transmits radio waves (sometimes referred to as tag radio waves). The RFID tag 12 stores a tag ID, which is unique information, and outputs the tag ID superimposed on the tag radio waves. The reachable range of the tag radio waves is approximately a radius of 5 to 10 meters, although this varies depending on external factors such as the placement of surrounding vehicles and roadside guardrails.

[0016] In the marker system 1 of this example, magnetic markers 10 are placed along the center of a lane 500, for example, as shown in FIG. 2. The magnetic markers 10, placed at intervals of, for example, 2 m, can be used for various driving assistance functions such as lane departure warning, lane keeping function, and autonomous driving. Furthermore, in this marker system 1, the vehicle 5 can use the magnetic markers 10 to identify its own vehicle position (absolute position of the vehicle). If the vehicle 5 can identify its own vehicle position, it can achieve a navigation function without using a positioning means such as a GPS (Global Positioning System).

[0017] Some of the magnetic markers 10 arranged along the lane 500 are tagged markers 10A, and the other magnetic markers 10 are untagged markers 10B. In FIG. 2, the tagged markers 10A are indicated by solid circles, and the untagged markers 10B are indicated by hollow circles. For example, one tagged marker 10A is arranged for every 10 magnetic markers. The tagged markers 10A are arranged with the north pole surface on the side holding the RFID tag 12 facing upward and the south pole surface facing underground. On the other hand, the untagged markers 10B are arranged with the south pole surface facing upward and the north pole surface facing underground. The marker system 1 can distinguish between the tagged markers 10A and the untagged markers 10B based on the magnetic polarity of the magnetic markers 10 that can be detected by the vehicle 5, i.e., the magnetic polarity (north pole) of the surface of the magnetic marker 10 facing upward. The magnetic marker 10 itself, which is detected as a north pole on the vehicle side, is the sign 1M of the tagged marker 10A.

[0018] Next, the configuration of the vehicle 5 that uses the marker system 1 and the procedure for using the marker system 1 by the vehicle 5 will be described with reference to FIG. (Vehicle configuration) The vehicle 5 is equipped with a sensor array 51 including multiple magnetic sensors 511, a tag reader 52 that receives tag radio waves from the RFID tag 12, an inertial measurement unit (IMU) 53, a control unit 55 that controls the sensor array 51 and the tag reader 52, a database 550 that stores the installation position (absolute position) of the magnetic marker 10, and the like.

[0019] The sensor array 51, which is an example of a magnetic measurement unit, is a unit including a plurality of magnetic sensors 511 and a detection processing circuit 510 that processes magnetic measurement values ​​of each magnetic sensor 511. In the rod-shaped sensor array 51, for example, 15 magnetic sensors 511 are arranged in a straight line at regular intervals. The magnetic sensors 511 are, for example, highly sensitive MI (Magneto Impedance) sensors.

[0020] The sensor array 51 is attached to the vehicle 5 so that its longitudinal direction is along the vehicle width direction and its center position coincides with the center of the vehicle 5. When the sensor array 51 detects the magnetic marker 10, it outputs information to the effect that the magnetic marker 10 has been detected, the magnetic polarity of the magnetic marker 10, and the relative lateral deviation of the vehicle 5 with respect to the magnetic marker 10. This lateral deviation can be determined as the deviation between the position directly above the magnetic marker 10 on the sensor array 51 and the center position of the sensor array 51.

[0021] The tag reader 52 is a unit that wirelessly supplies power to operate the RFID tag 12 and receives tag radio waves. The tag reader 52 demodulates the tag radio waves and reads the tag ID (information unique to the RFID tag 12). The tag reader 52 periodically communicates with the RFID tag 12 at a frequency of, for example, 3 kHz under the control of the control unit 55. Alternatively, the tag reader 52 may be configured to communicate with the RFID tag 12 when the magnetic marker 10 is detected or when the tag reader 52 is predicted to reach the RFID tag 12.

[0022] The inertial measurement unit 53 is a unit that estimates the displacement vector of the vehicle 5 using inertial navigation. The inertial measurement unit 53 is equipped with a two-axis magnetic sensor that is an electronic compass that measures orientation, a two-axis acceleration sensor that measures acceleration, and a two-axis gyro sensor that measures angular velocity. The inertial measurement unit 53 calculates the amount of displacement by double integration of acceleration and calculates the displacement vector from the reference position toward the destination by accumulating the amount of displacement along the orientation of the vehicle 5. By using the displacement vector estimated by the inertial measurement unit 53, it is possible to accurately estimate the position of the vehicle after it has passed a reference position whose absolute position is known.

[0023] The database 550 is realized by utilizing the storage area of ​​a storage device such as a hard disk drive or a solid state drive. The database 550 stores the placement position (absolute position) of each magnetic marker 10. Furthermore, for tagged markers 10A, the absolute position of the magnetic marker 10 (10A) is stored by linking it to the tag ID, which is information unique to the attached RFID tag 12. By referring to the database 550 using the tag ID of the RFID tag 12, the corresponding magnetic marker 10 (10A) can be identified and its absolute position can be read. Furthermore, by referring to the database 550 using the vehicle position estimated by inertial navigation or the like, the nearest magnetic marker 10 can be identified and its absolute position can be read.

[0024] The control unit 55 is a circuit that controls the sensor array 51, tag reader 52, inertial measurement unit 53, etc., and uses the outputs of these units to identify (including estimation of) the vehicle's position (the vehicle's absolute position). The control unit 55 can execute two types of processing to identify the vehicle's position. The first processing is performed when a tagged marker 10A is detected. The second processing is performed when an untagged marker 10B is detected.

[0025] (Procedure for using the marker system) The procedure by which the vehicle 5 identifies its own position using the marker system 1 will be described with reference to the flowchart in Fig. 4. The control unit 55 controls the sensor array 51, tag reader 52, and inertial measurement unit 53, and repeatedly acquires the output of each unit.

[0026] When the control unit 55 receives an output from the sensor array 51 indicating that the magnetic marker 10 has been detected (S101: YES), it determines whether the magnetic polarity of the magnetic marker 10 is a north pole or a south pole (S102). If the magnetic polarity of the detected magnetic marker 10 is a north pole, which is the magnetic polarity of the tagged marker 10A (S102: YES), the control unit 55 executes a first process described below to identify the vehicle's position (S103). On the other hand, if the magnetic polarity of the detected magnetic marker 10 is a south pole, which is the magnetic polarity of the untagged marker 10B (S102: NO), the control unit 55 executes a second process described below to identify the vehicle's position (S113). Then, the control unit 55 outputs the vehicle's position identified by the first or second process to an external device, such as a navigation device (S104).

[0027] The first process (S103) is performed when a tagged marker 10A is detected. As described above, when the sensor array 51 detects a magnetic marker 10, it outputs the magnetic polarity and the amount of lateral deviation relative to the magnetic marker 10. In the first process, the control unit 55 uses the tag ID of the RFID tag 12 to refer to the database 550 to identify the corresponding magnetic marker 10 and reads out its installation position (absolute position). Then, using the installation position (absolute position) of the magnetic marker 10 as a reference, it identifies a position shifted by the amount of lateral deviation obtained from the sensor array 51 as the vehicle position (absolute position of the vehicle).

[0028] The second process (S113) is a process performed when the vehicle 5 detects the tagless marker 10B on the right side in Figure 5. In the second process, the control unit 55 calculates an estimated position 5E that is shifted by the displacement vector Vr estimated by the inertial measurement unit 53, based on the vehicle position 5A identified when the magnetic marker 10 was last detected, regardless of whether the previous magnetic marker 10 was a tagged marker 10A or an tagless marker 10B. Here, the displacement vector Vr is a displacement vector estimated by the inertial measurement unit 53 until the vehicle 5 at the vehicle position 5A detects the above-mentioned tagless marker 10B.

[0029] The control unit 55 uses the estimated position 5E to refer to the database 550 to identify the nearest magnetic marker 10. In the case of Figure 5, the tagless marker 10B on the right side of the figure, which is closest to the estimated position 5E, is identified. The control unit 55 reads the installation position (absolute position) of the identified magnetic marker 10 (tagless marker 10B) from the database 550. Then, the control unit 55 uses the installation position of this magnetic marker 10 as a reference and identifies a position shifted by the amount of lateral deviation obtained from the sensor array 51 as the vehicle position 5R.

[0030] When using such a marker system 1, the magnetic marker 10 detected as a north pole is the mark 1M of the tagged marker 10A. The control unit 55 of the vehicle 5 switches between executing a first process corresponding to the tagged marker 10A or a second process corresponding to the untagged marker 10B depending on the magnetic polarity of the magnetic marker 10. If the magnetic polarity of the detected magnetic marker 10 is a south pole, the control unit 55 executes the second process without using tag radio waves, even if tag radio waves are being received.

[0031] For example, when vehicle 5 in Figure 6 detects tagless marker 10B (shown as an open circle) in its own lane 500A, it may be receiving tag radio waves from tagged marker 10A (shown as a filled circle) in the adjacent lane 500B. In the marker system 1 of this example, the magnetic polarity of the magnetic marker 10 detected by vehicle 5 is south, so the detected magnetic marker 10 can be identified as tagless marker 10B. In this case, because the detected magnetic marker 10 is tagless marker 10B, there is no risk of erroneously associating the tag radio waves being received with the detected magnetic marker 10.

[0032] FIG. 7 shows an example in which another magnetic marker 10C, which serves as a sign 1M, is placed near a tagged marker 10A. In FIG. 7(a), the magnetic marker 10C of the sign 1M is placed adjacent to the tagged marker 10A in the lane direction (corresponding to the direction of travel of the vehicle 5). In FIG. 7(b), the magnetic markers 10C of the sign 1M are placed on both sides of the tagged marker 10A in the lane width direction (corresponding to the width direction of the vehicle 5). Note that the magnetic marker 10C of the sign 1M may be a single magnetic marker adjacent to each other in the lane width direction. In this way, the sign may be a magnetic marker as a magnetic sign that can be detected using a sensor array 51 (magnetic measurement unit) provided in the vehicle. A magnetic marker as a sign may also be placed adjacent to the tagged marker 10A.

[0033] FIG. 8 shows an example in which the tagged marker 10A and the untagged marker 10B have different shapes. The tagged marker 10A is oval or rectangular, while the untagged marker 10B is circular. By magnetically detecting the longitudinal size, it is possible to distinguish between the tagged marker 10A shown in FIG. 8(a) and the untagged marker shown in FIG. 8(b). In other words, in the configuration of FIG. 8, the tagged marker 10A, which has an oval or rectangular shape, itself serves as a sign 1M for distinguishing between the tagged marker 10A and the untagged marker 10B. In this way, the tagged marker 10A and the untagged marker 10B have different surface shapes, which are the shapes that face the vehicle, and the tagged marker 10A, which has a different shape from the untagged marker 10B, may itself be used as a sign.

[0034] Methods for magnetically detecting the longitudinal size of the magnetic marker 10 include a method utilizing differences in magnetic distribution in a two-dimensional area including the magnetic marker 10, and a method utilizing differences in the time during which the magnetic field of the magnetic marker 10 is detected while the vehicle is traveling, i.e., the time during which the sensor array 51 passes over the magnetic marker 10. In this manner, the tagged marker 10A and the untagged marker 10B may have different longitudinal sizes in the direction of travel (lane direction) of the vehicle. In this case, a circuit that distinguishes between the tagged marker 10A and the untagged marker 10B based on the magnetic distribution in the direction of travel may be provided in the vehicle 5. For example, the circuit may perform threshold processing on the length of a section including the time point at which the magnetic marker 10 is detected, where a magnetic field having a strength (magnitude) exceeding a threshold is continuously distributed in the direction of travel, thereby distinguishing between the tagged marker 10A and the untagged marker 10B.

[0035] FIG. 9 shows an example in which the tagged marker 10A is rectangular and the untagged marker 10B is circular. The rectangular magnetic marker 10 and the circular magnetic marker 10 may have different two-dimensional magnetic distributions. Therefore, the tagged marker 10A can be identified by the two-dimensional magnetic distribution of the rectangular magnetic marker 10. In other words, the rectangular magnetic marker 10 itself serves as a sign 1M for distinguishing between the tagged marker 10A and the untagged marker 10B. Any vehicle may be equipped with a circuit that distinguishes between the tagged marker 10A and the untagged marker 10B based on the magnetic distribution of a two-dimensional area including the tagged marker 10A or the untagged marker 10B. The circuit that distinguishes between the tagged marker 10A and the untagged marker 10B based on the magnetic distribution of the two-dimensional area may be, for example, a circuit that distinguishes between the tagged marker 10A and the untagged marker 10B based on the size or shape of the area where a magnetic field exceeding a threshold strength (magnitude) is distributed.

[0036] As shown in Figure 10, the tagged marker 10A may be configured to reflect light. In this case, there may be a difference in brightness in the captured image between the tagged marker 10A and the untagged marker 10B. The difference in brightness, i.e., the brightly captured magnetic marker 10 itself, serves as a sign 1M for distinguishing between the tagged marker 10A and the untagged marker 10B. The captured image may be an image captured by a downward-facing camera capturing an image of the road surface on which the magnetic marker 10 is installed, or an image captured by a forward-facing camera capturing an image of the magnetic marker 10 located ahead.

[0037] For example, as shown in FIG. 10(a), a reflective patch 121 covering the RFID tag 12 may be attached to the surface of the tagged marker 10A. The reflective patch 121 may be cut out, for example, from a reflective sheet (not shown). Alternatively, as shown in FIG. 10(b), a reflective sheet 123 may be attached to the entire surface of the tagged marker 10A. In these cases, the reflective patch 121 or the reflective sheet 123 may serve as the marker 1M for the tagged marker 10A. Furthermore, as shown in FIG. 10(c), a magnetic sheet 10S may be used, which is a molded product made of a material kneaded with magnetic powder and a reflective material such as alumina powder or beads. If this magnetic marker 10 is placed exposed on the surface of the road, the magnetic sheet 10S itself will reflect light, and the magnetic marker 10 itself can serve as the marker 1M.

[0038] As shown in Figure 11, a marking 5M indicating the tagged marker 10A may be printed on the road surface. The marking 5M serves as a sign 1M for the tagged marker 10A. By applying image processing or the like to the captured image of the magnetic marker 10 and its surroundings, the marking 5M can be detected relatively easily, thereby making it possible to distinguish between the tagged marker 10A and the untagged marker 10B.

[0039] The tagged marker 10A and the untagged marker 10B may have different surface colors or patterns. The difference in color or pattern on the surface of the magnetic marker 10 can serve as a marker for distinguishing between the tagged marker 10A and the untagged marker 10B. The difference in color or pattern can be detected, for example, by applying image processing to the captured image of the magnetic marker 10.

[0040] In this example, a configuration is illustrated in which a label 1M is provided on tagged marker 10A as described above, making it possible to distinguish it from untagged marker 10B. Instead of this configuration, a label may be provided on untagged marker 10B, or different labels may be provided on both tagged marker 10A and untagged marker 10B. The graphical label may be a label that can be seen with the naked eye, or a label that cannot be seen with the naked eye but can be captured by a camera, such as a label that reflects or emits infrared or ultraviolet light.

[0041] Example 2 This example is based on the marker system 1 of Example 1 and is an example in which a tagged marker 10A is identified by code information represented by a combination of magnetic polarities of two or more magnetic markers 10. This will be described with reference to Fig. 12. In Fig. 12, tagged markers 10A are shown as filled-in circles, and untagged markers 10B are shown as open circles.

[0042] The code information is information consisting of a combination of the magnetic polarities of the tagged marker 10A and the seven magnetic markers 10 located upstream, a total of eight magnetic markers 10. This code information is eight-bit information, with the north pole represented as bit 1 and the south pole represented as bit zero. In this example, the tagged marker 10A and the seven magnetic markers 10 located upstream form the information providing unit 11. The information providing unit 11, which provides the vehicle with predetermined code information, serves as a sign 1M for distinguishing between the tagged marker 10A and the tagless marker 10B. A traveling vehicle can read the code information by detecting the magnetic polarities of the magnetic markers 10 that make up the information providing unit 11 in order from the upstream side.

[0043] 12, the information providing unit 11 as the sign 1M is attached to the tagged marker 10A in a manner including the tagged marker 10A. Alternatively, the information providing unit 11 may be configured using seven magnetic markers 10 upstream of the tagged marker 10A. In this case, the information providing unit 11 is attached to the tagged marker 10A by being arranged adjacent to the tagged marker 10A on the upstream side.

[0044] Note that the magnetic markers 10 may be arranged by specifying the magnetic polarity so that the magnetic markers 10 of the information providing unit 11 represent predetermined code information. Alternatively, the magnetic markers 10 may be arranged regardless of the magnetic polarity, and then the magnetic polarity of the magnetic markers 10 of the information providing unit 11 may be identified by magnetic measurement or the like, and a circuit may be provided to store the identified combination of magnetic polarities, and the combination of magnetic polarities stored in the circuit may be set as the predetermined code information. Alternatively, each magnetic marker 10 may be magnetized after being arranged so that the combination of magnetic polarities of the magnetic markers 10 of the information providing unit 11 represents predetermined code information.

[0045] Instead of the code information based on the combination of magnetic polarities of the magnetic marker 10, code information that can be read from a two-dimensional code such as a barcode or QR code (registered trademark) printed on the road surface may be used. The other configurations and effects are the same as those of the first embodiment.

[0046] Although specific examples of the present invention have been described in detail as examples, these examples merely disclose examples of the technology encompassed by the claims. Needless to say, the scope of the claims should not be interpreted as being limited by the configurations, numerical values, etc. of the specific examples. The claims encompass technologies that are obtained by variously modifying, changing, or appropriately combining the specific examples using publicly known technology and the knowledge of those skilled in the art. [Explanation of symbols]

[0047] 1. Marker System 1M sign 10 Magnetic Markers 10A tagged marker 10B untagged marker 10S Magnetic Sheet (Magnet) 11 Information provision department 12 RFID tags (wireless tags) 5 vehicles 500 lanes 51 Sensor array (magnetic measurement section) 510 Detection processing circuit 511 Magnetic Sensor 52 Tag Reader 53 Inertial Measurement Unit (IMU) 55 Control Unit 550 databases

Claims

1. A marker system for vehicle driving assistance control, including automatic driving control, including a plurality of magnetic markers arranged along a lane, A wireless tag capable of outputting information by wireless communication is attached to some of the magnetic markers among a plurality of magnetic markers arranged along the lane, a mark provided on the part of the magnetic markers in order to distinguish the part of the magnetic markers to which the wireless tag is attached from the other magnetic markers among the plurality of magnetic markers excluding the part of the magnetic markers; The magnetic markers arranged along the lanes are spaced apart at intervals narrower than the range of the radio waves transmitted by the wireless tags, the part of the magnetic markers among the plurality of magnetic markers arranged along the lane are arranged at intervals that exceed the reachable range of the tag radio waves, a tag reader provided in the vehicle for periodically communicating with the wireless tag to acquire the information; a circuit for associating the information acquired by the tag reader with the magnetic marker that is the source of the tag radio wave; The matching circuit is configured to match the information to any of the detected magnetic markers when any of the magnetic markers is detected and the sign is also detected, but not to match the information to any of the detected magnetic markers when any of the magnetic markers is detected but the sign is not detected, a marker system.

2. 2. The marker system according to claim 1, wherein the sign is a magnetic sign that can be detected by a magnetic measuring unit provided in a vehicle.

3. In claim 1, the sign is a magnetic marker as a magnetic sign that can be detected using a magnetic measuring unit equipped in a vehicle, and the magnetic marker as the sign is arranged adjacent to some of the magnetic markers.

4. 2. A marker system according to claim 1, wherein the shapes of the magnetic markers facing the vehicle are different from those of the other magnetic markers, and the magnetic markers having shapes different from those of the other magnetic markers themselves serve as the signs.

5. According to claim 4, the size of the longitudinal direction of the magnetic markers, which corresponds to the traveling direction of the vehicle, is different from that of the other magnetic markers, A marker system including a circuit that detects the signs by threshold processing on the length of the range in which magnetic fields exceeding a predetermined threshold are continuously distributed in the magnetic distribution in the direction of vehicle travel, and distinguishes between the some of the magnetic markers and the other magnetic markers.

6. 5. A marker system according to claim 4, including a circuit that distinguishes between the part of magnetic markers and the other magnetic markers based on the magnetic distribution of a two-dimensional area including the part of magnetic markers or the other magnetic markers.

7. 3. The marker system according to claim 1, wherein the marker is a visual marker that can be detected in an image of the magnetic marker captured by an imaging camera mounted on a vehicle.

8. 8. A marker system according to claim 7, wherein the magnetic marker is a molded product made of a material containing granular reflective material and magnetic powder, and is disposed in an exposed state on the surface side of the road surface.

9. 10. The marker system according to claim 1, wherein the sign is an information providing unit that provides predetermined code information to a vehicle, and the information providing unit is attached to some of the magnetic markers.

10. 10. The marker system according to claim 9, wherein the information providing unit is a bar code or a two-dimensional code printed on a road surface.

11. The marker system according to claim 10 , wherein the information providing unit includes two or more of the magnetic markers, and the code information is information based on a combination of magnetic polarities of the two or more magnetic markers.

12. The marker system according to claim 11, further comprising a circuit for storing a combination of magnetic polarities identified for the two or more magnetic markers included in the information providing unit after the markers have been installed on a road surface.

13. A method for detecting a plurality of magnetic markers arranged along a lane for driving assistance control of a vehicle, including automatic driving control, comprising: Some of the magnetic markers are provided with wireless tags capable of outputting information by wireless communication, and are provided with signs for distinguishing the some of the magnetic markers from the other magnetic markers, excluding the some of the magnetic markers; The magnetic markers arranged along the lanes are spaced apart at intervals narrower than the range of the radio waves transmitted by the wireless tags, the part of the magnetic markers among the plurality of magnetic markers arranged along the lane are arranged at intervals that exceed the reachable range of the tag radio waves, magnetically detecting the magnetic marker; A process of acquiring tag information output by the wireless tag attached to the magnetic marker; a process of detecting the signs attached to the part of the magnetic markers to which the wireless tags are attached; and a process of associating information acquired from the wireless tag with the part of the magnetic markers when the part of the magnetic markers is detected, periodically executing a process for acquiring the information; A magnetic marker detection method in which, when the magnetic marker is detected and the sign is detected, the information is associated with the detected magnetic marker by the association process, whereas, when the magnetic marker is detected but the sign is not detected, the information is not associated with the detected magnetic marker.

14. 14. The method for detecting a magnetic marker according to claim 13, wherein the sign is a magnetic sign that can be detected using a magnetic measuring unit provided in a vehicle.

15. 15. The method for detecting a magnetic marker according to claim 13, wherein the sign is a graphical sign that can be detected in an image of the magnetic marker captured by an imaging camera mounted on a vehicle.

16. In any one of claims 13 to 15, the sign is an information providing unit that provides predetermined code information to the vehicle, and the information providing unit is attached to some of the magnetic markers.

17. 17. The magnetic marker detection method according to claim 16, wherein the information providing unit includes two or more of the magnetic markers, and the code information is information based on a combination of magnetic polarities of the two or more magnetic markers.

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