Self-driving control system and self-driving control method

Abstract

Provided is a self-driving control system (102) for a vehicle (101) that travels on a road with installed markers (105) that emit a steady or quasi-steady magnetic field, the system comprising: a magnetic sensor array (104) which is installed in the vehicle (101) and which senses magnetism; and an information processing circuit (103) that generates an image indicating the magnetic field in an area closer to a marker (105) than the magnetic sensor array (104) according to the magnetic sensing result and basic equations for the steady and quasi-steady magnetic fields, and controls the travel of the vehicle (101) according to the image.

Description

Automatic driving control system and automatic driving control method

[0001] The present disclosure relates to an automatic driving control system for a vehicle traveling on a road on which markers are installed.

[0002] Conventionally, automatic driving of vehicles has been studied. The technology described in Patent Document 1 relates to such automatic driving. Specifically, Patent Document 1 discloses an automatic driving system for a vehicle that performs automatic steering and driving by detecting magnetic markers laid along the vehicle driving route.

[0003] Japanese Patent Application Laid-Open No. 2005-202478

[0004] However, the magnetic field can be affected by manholes, fallen objects, floor slabs buried under asphalt, reinforcing bars for concrete, reinforcing bars in bridges, water pipes, culverts, and utility sewer covers, etc. This can make it difficult to identify markers and control vehicle movement.

[0005] Therefore, the present disclosure provides an automatic driving control system and the like that can appropriately control the driving of a vehicle in accordance with markers.

[0006] An autonomous driving control system according to one aspect of the present disclosure is an autonomous driving control system for a vehicle traveling on a road on which a marker that emits a steady magnetic field or a quasi-steady magnetic field is installed, and includes a magnetic sensor array mounted on the vehicle that detects magnetism, and an information processing circuit that generates an image showing the magnetic field in an area closer to the marker than the magnetic sensor array according to the magnetic detection results and basic equations of steady magnetic fields and quasi-steady magnetic fields, and controls the traveling of the vehicle according to the image.

[0007] These comprehensive or specific aspects may be realized as a system, an apparatus, a method, an integrated circuit, a computer program, or a non-transitory recording medium such as a computer-readable CD-ROM, or may be realized as any combination of a system, an apparatus, a method, an integrated circuit, a computer program, and a recording medium.

[0008] According to one aspect of the present disclosure, it is possible to appropriately control the driving of a vehicle in accordance with a marker.

[0009] FIG. 1 is a conceptual diagram showing the configuration of an autonomous driving control system according to an embodiment. FIG. 2 is a flowchart showing the operation of the autonomous driving control system according to an embodiment. FIG. 3 is a perspective view showing a vehicle according to an embodiment. FIG. 4 is a side view showing a vehicle according to an embodiment. FIG. 5 is a conceptual diagram showing a first example of a magnetic sensor array according to an embodiment. FIG. 6 is a conceptual diagram showing a second example of a magnetic sensor array according to an embodiment. FIG. 7 is a conceptual diagram showing a first example of reconstruction according to an embodiment. FIG. 8 is a conceptual diagram showing a coordinate system for the first example of reconstruction according to an embodiment. FIG. 9 is a conceptual diagram showing a third example of a magnetic sensor array according to an embodiment. FIG. 10 is a conceptual diagram showing a fourth example of a magnetic sensor array according to an embodiment. FIG. 11 is a conceptual diagram showing a second example of reconstruction according to an embodiment. FIG. 12 is a conceptual diagram showing a coordinate system for the second example of reconstruction according to an embodiment. FIG. 13 is a block diagram showing the details of the configuration of an autonomous driving control system according to an embodiment. FIG. 14 is a conceptual diagram showing markers, a measured image, and a reconstructed image according to an embodiment. FIG. 15 is a conceptual diagram showing a first example of a marker according to an embodiment. FIG. 16 is a conceptual diagram showing a second example of a marker according to an embodiment. FIG. 17 is a conceptual diagram showing a third example of a marker in the embodiment. FIG. 18 is a conceptual diagram showing a magnetic field around a magnetic wire in the embodiment. FIG. 19 is a conceptual diagram showing a reconstructed image when a magnetic wire in the embodiment is used. FIG. 20 is a conceptual diagram showing a fourth example of a marker in the embodiment. FIG. 21 is a conceptual diagram showing the magnetic field direction around a concentric marker in the embodiment. FIG. 22 is a conceptual diagram showing a reconstructed image when a concentric marker in the embodiment is used. FIG. 23 is a conceptual diagram showing a fifth example of a marker in the embodiment. FIG. 24 is a conceptual diagram showing an induction circuit in the embodiment. FIG. 25 is a conceptual diagram showing another example of an electrical conductor in the embodiment. FIG. 26 is a conceptual diagram showing yet another example of an electrical conductor in the embodiment. FIG. 27 is a conceptual diagram showing an example of an electrical conductor corresponding to the first example of a marker in the embodiment.FIG. 28 is a conceptual diagram showing an example of an electrical conductor corresponding to the second example of the marker in the embodiment. FIG. 29 is a conceptual diagram showing another example of an electrical conductor corresponding to the first example of the marker in the embodiment. FIG. 30 is a conceptual diagram showing another example of an electrical conductor corresponding to the second example of the marker in the embodiment. FIG. 31 is a conceptual diagram showing a first specific example of a magnetic sensor array in the embodiment. FIG. 32 is a conceptual diagram showing a second specific example of a magnetic sensor array in the embodiment. FIG. 33 is a conceptual diagram showing a third specific example of a magnetic sensor array in the embodiment. FIG. 34 is a conceptual diagram showing a fourth specific example of a magnetic sensor array in the embodiment. FIG. 35 is a conceptual diagram showing a fifth specific example of a magnetic sensor array in the embodiment. FIG. 36 is a conceptual diagram showing a sixth specific example of a magnetic sensor array in the embodiment. FIG. 37 is a conceptual diagram showing a seventh specific example of a magnetic sensor array in the embodiment. FIG. 38 is a conceptual diagram showing an eighth specific example of a magnetic sensor array in the embodiment. FIG. 39 is a conceptual diagram showing a magnetic shield in the embodiment. FIG. 40 is a flowchart showing a driving control process in the embodiment. FIG. 41 is a conceptual diagram of a basic experiment related to the embodiment. Fig. 42 is an image diagram showing a first measurement image obtained in a basic experiment related to the embodiment. Fig. 43 is an image diagram showing a second measurement image obtained in a basic experiment related to the embodiment. Fig. 44 is an image diagram showing a reconstructed image obtained in a basic experiment related to the embodiment. Fig. 45 is a conceptual diagram showing the relationship between a measurement image and a reconstructed image for verification related to the embodiment. Fig. 46 is a conceptual diagram showing a tracked marker for verification related to the embodiment. Fig. 47 is a conceptual diagram showing a dummy marker for verification related to the embodiment. Fig. 48 is a graph showing verification results related to the embodiment.

[0010] Generally, automated driving refers to the automation of driving tasks. Levels of automated driving are defined, from level 0 to level 5. Of these levels, level 5 is also called fully automated driving. At level 5, all driving tasks up to the destination are performed by the system. Therefore, the driving tasks are not monitored by a human driver. Therefore, malfunctions are not tolerated.

[0011] Furthermore, various sensing technologies for realizing autonomous driving are being considered. Specifically, the use of cameras, LiDAR (Light Detection and Ranging), millimeter-wave radar, ultrasonic sonar, and the like for autonomous driving is being considered. For example, a camera is used to perform object detection and object recognition, which then enables collision avoidance and white line recognition. Furthermore, for example, LiDAR, millimeter-wave radar, ultrasonic sonar, and the like are used to measure the distance to an object and perform collision avoidance.

[0012] Furthermore, the realization of autonomous driving by AI (artificial intelligence) composed of, for example, neural networks, is being considered. More specifically, in AI, driving tasks to be performed by a driver are learned in advance along with images obtained from a camera. Then, when the same image is obtained from the camera, the same driving task is reproduced by AI. For example, white line recognition is performed by the camera and AI, and the driving task is reproduced so that the vehicle moves along the white line. As a result, the vehicle moves along the road.

[0013] Furthermore, for example, the use of markers such as magnetic markers for autonomous driving is also being considered. Specifically, a magnetic sensor mounted on a vehicle detects markers installed on the road. Then, the vehicle is controlled to move along multiple markers installed along the road.

[0014] For example, depending on the weather, it may be difficult for cameras and AI to recognize white lines. Therefore, depending on the weather, malfunctions may occur, making autonomous driving difficult. Therefore, it is effective to use markers that are less affected by weather for autonomous driving.

[0015] However, the magnetic field can be affected by manholes, fallen objects, floor slabs buried under asphalt, reinforcing bars for concrete, reinforcing bars in bridges, water pipes, culverts, and utility sewer covers, etc. This can make it difficult to identify markers and control vehicle movement.

[0016] Therefore, for example, an autonomous driving control system according to one aspect of the present disclosure is an autonomous driving control system for a vehicle traveling on a road on which a marker that emits a steady magnetic field or a quasi-steady magnetic field is installed, and includes a magnetic sensor array mounted on the vehicle that detects magnetism, and an information processing circuit that generates an image showing the magnetic field in an area closer to the marker than the magnetic sensor array according to the magnetic detection results and basic equations of steady magnetic fields and quasi-steady magnetic fields, and controls the traveling of the vehicle according to the image.

[0017] This allows the autonomous driving control system to control the traveling of the vehicle according to an image showing the magnetic field in an area closer to the marker than the magnetic sensor array. This image is expected to show the marker with high accuracy. Therefore, it is expected that the marker will be properly identified. Therefore, the autonomous driving control system can properly control the traveling of the vehicle according to the marker.

[0018] Also, for example, the information processing circuit acquires the speed of the vehicle, converts the temporal changes in the sensing results into spatial changes in accordance with the speed, and generates the image in accordance with the sensing results in which the temporal changes have been converted into the spatial changes and the basic equation.

[0019] This allows the autonomous driving control system to fully capture the temporal changes in the sensing results and the spatial changes in the magnetic field according to the vehicle speed, and therefore the autonomous driving control system can appropriately generate an image showing the magnetic field.

[0020] Furthermore, for example, the magnetic sensor array is configured with one or more two-dimensional magnetic sensor arrays along the longitudinal and lateral directions of the vehicle.

[0021] This allows the autonomous driving control system to fully capture spatial variations in the magnetic field using the two-dimensional magnetic sensor array, thereby enabling the autonomous driving control system to appropriately generate an image showing the magnetic field.

[0022] Also, for example, the magnetic sensor array is configured with one or more one-dimensional magnetic sensor arrays along the left-right direction of the vehicle.

[0023] This allows the automatic driving control system to appropriately control vehicle driving using fewer resources and at low cost.

[0024] Also, for example, the magnetic sensor array senses the magnetism in one layer along the longitudinal direction and the lateral direction of the vehicle.

[0025] This allows the autonomous driving control system to simply sense magnetism and perform processing with a low amount of calculation.

[0026] Furthermore, for example, the magnetic sensor array senses the magnetic field in two layers along the longitudinal direction and the lateral direction of the vehicle.

[0027] This allows the autonomous driving control system to properly acquire the gradient of the magnetic field in the vertical direction and properly generate an image showing the magnetic field.

[0028] Furthermore, for example, the information processing circuit generates the image in accordance with the sensed result and the fundamental equation, in accordance with the equation (5) described below, in which H ｉ (x, y, z) indicates the i component of the magnetic field at the coordinate position (x, y, z), where i indicates x, y, or z, z indicates a coordinate value in the z direction from top to bottom of the vehicle, x indicates a coordinate value in the x direction perpendicular to the z direction, and y indicates a coordinate value in the y direction perpendicular to the z direction and the x direction, and f(k ｘ , k ｙ ) indicates the sensing result at (x, y, 0) which is the measurement plane. ｉ (x, y, 0) and k ｘ denotes the wave number with respect to x, and k ｙ denotes the wave number with respect to y.

[0029] This allows the autonomous driving control system to use the sensing results to appropriately generate an image showing the magnetic field in an area closer to the marker than the magnetic sensor array.

[0030] Furthermore, for example, the information processing circuit generates the image in accordance with the sensed result and the fundamental equation, in accordance with Equation (9) described later, in which H ｉ (x, y, z) indicates the i component of the magnetic field at the coordinate position (x, y, z), where i indicates x, y, or z, z indicates a coordinate value in the z direction from top to bottom of the vehicle, x indicates a coordinate value in the x direction perpendicular to the z direction, and y indicates a coordinate value in the y direction perpendicular to the z direction and the x direction, and f(k ｘ , k ｙ ) indicates the sensing result at (x, y, 0) which is the measurement plane. ｉ (x, y, 0) and g(k ｘ , k ｙ ) denotes the gradient in the z direction of the sensing result on the measurement plane (x, y, 0), ｉ (x, y, z) | ｚ＝０ shows the two-dimensional Fourier transform image of k ｘ denotes the wave number with respect to x, and k ｙ denotes the wave number with respect to y.

[0031] This allows the autonomous driving control system to use the sensing results and their gradients to appropriately generate an image showing the magnetic field in an area closer to the marker than the magnetic sensor array.

[0032] Also, for example, the autonomous driving control system further includes at least one of a camera, LiDAR, millimeter-wave radar, ultrasonic sonar, and GPS receiver mounted on the vehicle, and the information processing circuit further controls the driving of the vehicle in accordance with at least one of the camera, LiDAR, millimeter-wave radar, ultrasonic sonar, and GPS receiver.

[0033] This allows the autonomous driving control system to control the vehicle's driving according to various information obtained from cameras, LiDAR, millimeter-wave radar, ultrasonic sonar, or GPS receivers.

[0034] Also, for example, the automatic driving control system further includes the marker installed on the road.

[0035] This allows the automatic driving control system to control the driving of the vehicle according to the markers provided in the automatic driving control system.

[0036] Also, for example, the autonomous driving control system includes a plurality of markers each installed on the road as the marker, and the plurality of markers emit a steady magnetic field or a quasi-steady magnetic field with a plurality of magnetic patterns for controlling the driving of the vehicle.

[0037] This allows the automatic driving control system to control the vehicle's driving in accordance with multiple magnetic patterns.

[0038] Furthermore, for example, each of the plurality of magnetic patterns is a concentric magnetic pattern.

[0039] This allows the autonomous driving control system to suppress the influence of the vehicle's orientation when identifying magnetic patterns.

[0040] Furthermore, for example, each of the plurality of magnetic patterns is a barcode-like magnetic pattern.

[0041] This allows the autonomous driving control system to control the vehicle's driving in accordance with the barcode, which can simply display a variety of information.

[0042] Furthermore, for example, each of the plurality of magnetic patterns is a two-dimensional code-like magnetic pattern.

[0043] This allows the automatic driving control system to control the vehicle's driving in accordance with the two-dimensional code, which can indicate a wider variety of information.

[0044] Also, for example, the marker represents a code sequence for controlling the running of the vehicle by an arrangement of multiple magnetic poles, the code sequence including a code for error detection, the information processing circuit reads out the code sequence according to the image, determines whether the read code sequence includes an error according to the code included in the read code sequence, and if it is determined that the read code sequence does not include an error, controls the running of the vehicle according to the read code sequence.

[0045] This allows the autonomous driving control system to read the code sequence from the marker via an image showing the magnetic field. Furthermore, the autonomous driving control system can determine whether the read code sequence contains an error according to the error detection code. Therefore, the autonomous driving control system can appropriately control the vehicle's driving according to the highly reliable code sequence.

[0046] Furthermore, for example, the marker has a wire-like shape.

[0047] This allows the automatic driving control system to control the vehicle's driving along the wire-like shape.

[0048] Furthermore, for example, the marker is a magnetic material having magnetism.

[0049] This allows the automated driving control system to control the vehicle's driving using simple markers.

[0050] Furthermore, for example, the marker is an electrical conductor having electrical conductivity.

[0051] This allows the automatic driving control system to use the electrical conductor as a marker to appropriately control the vehicle's driving.

[0052] Also, for example, the autonomous driving control system further includes an induction circuit mounted on the vehicle that induces a first magnetic field component, and the marker emits a steady magnetic field or a quasi-steady magnetic field by inducing a second magnetic field component by the first magnetic field component.

[0053] This allows the autonomous driving control system to properly generate a magnetic field from the marker even when an electrical conductor is used as the marker.

[0054] Also, for example, a vehicle according to one aspect of the present disclosure is equipped with the autonomous driving control system.

[0055] This allows the vehicle to control its travel in accordance with an image showing the magnetic field in an area closer to the marker than the magnetic sensor array.

[0056] Furthermore, for example, an autonomous driving control method according to one aspect of the present disclosure is an autonomous driving control method for a vehicle traveling on a road on which a marker that emits a steady magnetic field or a quasi-steady magnetic field is installed, in which a magnetic sensor array mounted on the vehicle senses magnetism, and generates an image showing the magnetic field in a region closer to the marker than the magnetic sensor array according to the magnetic sensing results and basic equations for steady magnetic fields and quasi-steady magnetic fields, and controls the traveling of the vehicle according to the image.

[0057] This makes it possible to control the running of a vehicle according to an image showing the magnetic field in an area closer to the marker than the magnetic sensor array. This image is expected to show the marker with high accuracy. Therefore, it is expected that the marker will be properly identified. Therefore, it becomes possible to properly control the running of a vehicle according to the marker.

[0058] Hereinafter, embodiments will be described with reference to the drawings. Note that the embodiments described below are all comprehensive or specific examples. The numerical values, shapes, materials, components, the arrangement and connection of the components, steps, the order of steps, and the like shown in the following embodiments are merely examples and are not intended to limit the scope of the claims.

[0059] In addition, the magnetic field components in this description are components that make up the magnetic field. The magnetic field components may be each of multiple magnetic fields that are superimposed on the overall magnetic field. In addition, the device in this description may include multiple components that are distributed.

[0060] (Embodiment) Fig. 1 is a conceptual diagram showing the configuration of an automatic driving control system in this embodiment. A vehicle 101 shown in Fig. 1 is a machine that travels on a road, and more specifically, is an automobile. The vehicle 101 can also be expressed as an automatically driven car.

[0061] The autonomous driving control system 102 is a system that controls the traveling of the vehicle 101. Specifically, the autonomous driving control system 102 controls the traveling of the vehicle 101 according to markers 105 installed on the road. In controlling the traveling of the vehicle 101, the autonomous driving control system 102 may control the vehicle 101 to go straight, turn left, turn right, stop, etc.

[0062] For example, a plurality of markers 105 are placed along a road. Specifically, the plurality of markers 105 are placed on the road surface and covered with a protective agent 117. The autonomous driving control system 102 causes the vehicle 101 to travel along the plurality of markers 105 placed along the road.

[0063] The automatic driving control system 102 also includes an information processing circuit 103 and a magnetic sensor array 104 .

[0064] The information processing circuit 103 is an electric circuit that processes information. The information processing circuit 103 generates an image showing the magnetic field in a region closer to the marker 105 than the magnetic sensor array 104, in accordance with the results of the magnetic field sensed by the magnetic sensor array 104 and the basic equations of the steady magnetic field and the quasi-steady magnetic field.

[0065] For example, a stationary magnetic field is a static magnetic field that does not change over time. Also, for example, a quasi-stationary magnetic field is a magnetic field whose temporal change is smaller than a reference. Specifically, a quasi-stationary magnetic field may be a magnetic field that changes at a frequency equal to or lower than a reference frequency. This reference frequency may be 1 kHz, several hundred Hz, several tens of Hz, or several Hz.

[0066] Furthermore, the region closer to the marker 105 than the magnetic sensor array 104 may specifically be a region closer to the estimated position of the marker 105 than the magnetic sensor array 104, or may be defined as a position lower than the magnetic sensor array 104. Furthermore, the region closer to the marker 105 than the magnetic sensor array 104 may be a region closer to the road surface than the magnetic sensor array 104. Furthermore, the brightness of the image may correspond to the strength of the magnetic field. Then, the information processing circuit 103 controls the traveling of the vehicle 101 according to the generated image.

[0067] For example, the information processing circuit 103 reads, from the generated image, information for controlling the vehicle 101. Specifically, the information processing circuit 103 reads information such as going straight, turning left, turning right, or stopping, and then controls the traveling of the vehicle 101 in accordance with the read information.

[0068] The magnetic sensor array 104 is a device that senses magnetism. The magnetic sensor array 104 senses the magnetism of a magnetic field including a magnetic field component induced by a marker 105 installed on a road. Specifically, for example, the magnetic sensor array 104 is composed of a plurality of magnetic sensors, and each magnetic sensor senses the magnetism of a magnetic field including a magnetic field component induced by a marker 105 installed on a road.

[0069] The marker 105 induces a magnetic field component. Specifically, the marker 105 emits a stationary magnetic field or a quasi-stationary magnetic field. For example, a plurality of markers 105 are installed along a road. The marker 105 may be referred to as a magnetic marker.

[0070] Furthermore, for example, the marker 105 may be a magnetic material (specifically, a ferromagnetic material) having magnetism, such as a permanent magnet. The marker 105, which is a magnetic material having magnetism, may induce a magnetic field component. Furthermore, for example, the marker 105 may be an electrically conductive material having conductivity, such as a ring or a coil. The marker 105, which is an electrically conductive material having conductivity, may induce a magnetic field component based on electromagnetic induction. This will be described in detail later.

[0071] Furthermore, for example, the marker 105 may use an arrangement of multiple magnetic poles to represent a code sequence for controlling the traveling of the vehicle 101. The information processing circuit 103 may read out the code sequence according to the generated image, and control the traveling of the vehicle 101 according to the read code sequence.

[0072] Furthermore, for example, the code sequence represented by the marker 105 may include a code for error detection. The information processing circuit 103 may determine whether or not the read code sequence includes an error according to the code for error detection. If the information processing circuit 103 determines that the read code sequence does not include an error, it may control the running of the vehicle 101 according to the read code sequence.

[0073] Furthermore, if the information processing circuit 103 determines that the read code sequence contains an error, it may ignore the read code sequence. In this case, the information processing circuit 103 may output an alert indicating that the read code sequence contains an error. Alternatively, in this case, the information processing circuit 103 may correct the error and control the running of the vehicle 101 in accordance with the error-corrected code sequence.

[0074] The protective agent 117 covers the markers 105 and forms a layer for protecting the markers 105. A protective film made of a resin or the like may be used as the protective agent 117. Alternatively, the layer of the protective agent 117 may be formed by applying a protective coating to the plurality of markers 105 and the road surface, etc.

[0075] Fig. 2 is a flowchart showing the operation of the automatic driving control system 102 shown in Fig. 1. The automatic driving control system 102 performs the operation shown in Fig. 2.

[0076] First, the magnetic sensor array 104 of the autonomous driving control system 102 senses magnetism (S101). Next, the information processing circuit 103 of the autonomous driving control system 102 generates an image showing the magnetic field in a region closer to the marker 105 than the magnetic sensor array 104, based on the magnetic sensing result and the fundamental equations of steady-state magnetic fields and quasi-steady magnetic fields (S102). Then, the information processing circuit 103 controls the traveling of the vehicle 101 in accordance with the generated image (S103).

[0077] Fig. 3 is a perspective view showing the vehicle 101 shown in Fig. 1. As shown in Fig. 3, the vehicle 101 is controlled to travel along a plurality of markers 105 covered with a protective agent 117. The magnetic sensor array 104 mounted on the vehicle 101 is disposed in the lower portion of the vehicle 101.

[0078] 3 , at least one of one or more cameras 106, one or more LiDARs 107, one or more wave sensors 108, and a GPS (Global Positioning System) receiver 109 may be mounted on the vehicle 101. Here, the wave sensor 108 may be a millimeter-wave radar, an ultrasonic sonar, or a combination thereof.

[0079] The information processing circuit 103 may avoid a collision by controlling the traveling of the vehicle 101 according to information obtained from one or more cameras 106, one or more LiDARs 107, and one or more wave sensors 108. In this case, the information processing circuit 103 may perform object detection and object recognition using a neural network to avoid the collision.

[0080] That is, it may be possible to combine control for driving the vehicle 101 along a road using the markers 105 with control for collision avoidance using one or more cameras 106, one or more LiDARs 107, and one or more wave sensors 108. Furthermore, the information processing circuit 103 may obtain position information of the vehicle 101 from the GPS receiver 109, and control the driving of the vehicle 101 in accordance with the position information.

[0081] The autonomous driving control system 102 may include at least one of one or more cameras 106, one or more LiDARs 107, one or more wave sensors 108, and a GPS receiver 109.

[0082] Fig. 4 is a side view showing the vehicle 101 shown in Fig. 1. As shown in Fig. 4, the magnetic sensor array 104 is disposed in the lower part of the vehicle 101. The magnetic sensor array 104 senses the magnetism of the magnetic field including the magnetic field component induced by the marker 105.

[0083] Fig. 5 is a conceptual diagram showing a first example of the magnetic sensor array 104 shown in Fig. 1. In this example, the magnetic sensor array 104 is a two-dimensional magnetic sensor array extending along the longitudinal and lateral directions of the vehicle 101. That is, the magnetic sensor array 104 is composed of a plurality of magnetic sensors 110 arranged in the longitudinal and lateral directions of the vehicle 101.

[0084] Fig. 6 is a conceptual diagram showing a second example of the magnetic sensor array 104 shown in Fig. 1. In this example, the magnetic sensor array 104 is a one-dimensional magnetic sensor array extending along the left-right direction of the vehicle 101. That is, the magnetic sensor array 104 is composed of a plurality of magnetic sensors 110 arranged in the left-right direction of the vehicle 101.

[0085] 7 is a conceptual diagram showing a first example of reconstruction in this embodiment. For example, in the example of FIG. 6, as the vehicle 101 travels, the magnetic sensor array 104, which is a one-dimensional magnetic sensor array, can scan a two-dimensional measurement surface above the marker 105. This allows for the acquisition of magnetic sensing results on the two-dimensional measurement surface, i.e., two-dimensional sensing results.

[0086] For example, the information processing circuit 103 acquires the speed of the vehicle 101 from a speedometer or the like of the vehicle 101, and converts the temporal change in the sensing result of the magnetic sensor array 104 into a spatial change in accordance with the speed of the vehicle 101. Specifically, the faster the speed of the vehicle 101, the more the temporal change in the sensing result of the magnetic sensor array 104 may be converted into a spatial change over a wider range. This allows appropriate two-dimensional sensing results to be obtained.

[0087] The above operation may also be applied to the example of Fig. 5. Specifically, it can be considered that a one-dimensional magnetic sensor array exists for each column along the left-right direction in the magnetic sensor array 104, which is a two-dimensional magnetic sensor array. Therefore, according to the above operation, a two-dimensional sensing result is obtained for each column along the left-right direction. As a result, a plurality of two-dimensional sensing results are obtained for each of the columns along the left-right direction.

[0088] Then, one two-dimensional sensing result obtained by combining the multiple two-dimensional sensing results may be used for subsequent processing, or each of the multiple two-dimensional sensing results may be used for subsequent processing.

[0089] The information processing circuit 103 generates an image showing the magnetic field in a reconstruction plane closer to the marker 105 than the measurement plane, based on the magnetic sensing results in the measurement plane and the basic equations of stationary and quasi-stationary magnetic fields.

[0090] Fig. 8 is a conceptual diagram showing a coordinate system for reconstruction shown in Fig. 7. Fig. 8 shows the measurement plane and reconstruction plane in an xyz orthogonal coordinate system.

[0091] Z is a coordinate value in the z direction from top to bottom of the vehicle 101, x is a coordinate value in the x direction perpendicular to the z direction, and y is a coordinate value in the y direction perpendicular to the z direction and the x direction. For example, the x direction corresponds to the left-right direction of the vehicle 101, and the y direction corresponds to the front-rear direction of the vehicle 101. Alternatively, the x direction corresponds to the front-rear direction of the vehicle 101, and the y direction corresponds to the left-right direction of the vehicle 101. Furthermore, magnetism is sensed at z=0. In other words, z=0 corresponds to the measurement plane.

[0092] For example, the fundamental equation for a steady magnetic field and a quasi-steady magnetic field in a free space where no magnetic source exists, including an induced magnetic field, is expressed by the Laplace equation. Specifically, H, which is the i-component of the magnetic field vector in the xyz orthogonal coordinate system, ｉ For (x, y, z), the following equation (1) holds:

[0093]

[0094] For example, i is x, y, or z. Δ is the Laplacian, also called the Laplace operator. The general solution of the above equation (1) is expressed as the following equation (2) as the sum of an exponentially increasing term and an exponentially decaying term in the z direction.

[0095]

[0096] In the above formula (2), k ｘ and k ｙrepresent the wave number in the x direction and the wave number in the y direction, respectively. ｘ , k ｙ ) and b(k ｘ , k ｙ ) is k ｘ and k ｙ In this example, the magnetic source is assumed to be on the positive side in the z direction. Therefore, for convenience, the term that exponentially decays in the z direction is omitted. Therefore, equation (2) can be expressed as the following equation (3).

[0097]

[0098] For example, by measurement, H, which is the i-component of the magnetic field vector in the plane z=0, ｉ (x, y, 0) is obtained. Using this, a(k ｘ , k ｙ ) is calculated as shown in the following formula (4).

[0099]

[0100] Here, f(k ｘ , k ｙ ) is H ｉ This is a two-dimensional Fourier transform image of (x, y, 0). By substituting equation (4) into equation (3), H ｉ (x, y, z) is obtained as shown in the following equation (5).

[0101]

[0102] As described above, equation (5) representing the magnetic field (specifically, the i component of the magnetic field vector) is derived according to the magnetic sensing results and the basic equations of stationary and quasi-stationary magnetic fields.

[0103] In other words, the Dirichlet boundary condition H ｉ Using (x, y, 0), it is possible to derive a solution to the Laplace equation, which is the fundamental equation for the steady magnetic field and quasi-steady magnetic field in the free space. Specifically, H at any z coordinate in a space where no magnetic source exists can be calculated. ｉ(x, y, z) can be derived. That is, it is possible to reconstruct the magnetic field in the reconstruction plane close to the marker 105 from the magnetic field in the measurement plane, which is the xy plane where z=0.

[0104] For example, H ｉ (x, y, 0) is obtained as a sensing result on the measurement plane at z=0. Then, H obtained from the sensing result ｉ By performing a two-dimensional Fourier transform of (x, y, 0) with respect to x and y, f(k ｘ , k ｙ ) is obtained by two-dimensional Fourier transform. ｘ , k ｙ ), and the z-coordinate value z of the reconstruction plane ａ By substituting into equation (5), H on the reconstruction surface ｉ (x, y, z ａ ) is obtained. This makes it possible to accurately obtain information about the magnetic field on the reconstruction plane.

[0105] Finally, H on the reconstruction surface ｉ (x, y, z ａ ) is expressed as the following equation (6).

[0106]

[0107] The information processing circuit 103 calculates an image showing the magnetic field on the reconstruction plane by calculating H in the above equation (6). ｉ (x, y, z ａ ) may be generated.

[0108] Although one measurement surface is used in the examples described with reference to Figures 5 to 8, two measurement surfaces may also be used. This will be specifically described below with reference to Figures 9 to 12.

[0109] Fig. 9 is a conceptual diagram showing a third example of the magnetic sensor array 104 shown in Fig. 1. In this example, the magnetic sensor array 104 is a combination of a first two-dimensional magnetic sensor array and a second two-dimensional magnetic sensor array that are aligned along the longitudinal direction and the lateral direction of the vehicle 101, respectively.

[0110] The first two-dimensional magnetic sensor array and the second two-dimensional magnetic sensor array along the longitudinal and lateral directions of the vehicle 101 are each composed of a plurality of magnetic sensors 110 arranged in the longitudinal and lateral directions of the vehicle 101. In addition, in the vertical direction of the vehicle 101, the positions of the first two-dimensional magnetic sensor array and the second two-dimensional magnetic sensor array are different from each other.

[0111] Fig. 10 is a conceptual diagram showing a fourth example of the magnetic sensor array 104 shown in Fig. 1. In this example, the magnetic sensor array 104 is a combination of a first one-dimensional magnetic sensor array and a second one-dimensional magnetic sensor array, each of which is aligned along the left-right direction of the vehicle 101.

[0112] Each of the first one-dimensional magnetic sensor array and the second one-dimensional magnetic sensor array along the left-right direction of the vehicle 101 is composed of a plurality of magnetic sensors 110 arranged in the left-right direction of the vehicle 101. In addition, in the up-down direction of the vehicle 101, the position of the first one-dimensional magnetic sensor array and the position of the second one-dimensional magnetic sensor array are different from each other.

[0113] In this example, the positions of the first one-dimensional magnetic sensor array and the second one-dimensional magnetic sensor array are different in the longitudinal direction of the vehicle 101, but they may also be the same.

[0114] Fig. 11 is a conceptual diagram showing a second example of reconstruction in this embodiment. For example, in the example of Fig. 10, as the vehicle 101 travels, the magnetic sensor array 104, which is a combination of two one-dimensional magnetic sensor arrays, can scan two measurement planes above the marker 105. This allows magnetic sensing results to be obtained on the two measurement planes. In the example of Fig. 9, magnetic sensing results on the two measurement planes are also obtained. In the examples of Figs. 9 and 10, the speed of the vehicle 101 may be used, as in the examples of Figs. 5 and 6.

[0115] The information processing circuit 103 generates an image showing the magnetic field in a reconstruction plane closer to the marker 105 than the two measurement planes, based on the magnetic sensing results in the two measurement planes and the basic equations of stationary and quasi-stationary magnetic fields.

[0116] Fig. 12 is a conceptual diagram showing a coordinate system for reconstruction shown in Fig. 11. Fig. 12 shows two measurement planes and a reconstruction plane in an xyz Cartesian coordinate system. As in the example of Fig. 8, z is a coordinate value in the z direction from top to bottom of the vehicle 101, x is a coordinate value in the x direction perpendicular to the z direction, and y is a coordinate value in the y direction perpendicular to the z and x directions. Furthermore, magnetism is sensed at z = 0 and z = d. In other words, z = 0 and z = d correspond to the two measurement planes.

[0117] As described above, H, which is the i component of the magnetic field vector in the xyz orthogonal coordinate system, ｉ The above formula (1) holds true for (x, y, z). The general solution of the above formula (1) is expressed as the above formula (2).

[0118] In this example, it is assumed that magnetic sources exist on both the positive and negative sides in the z direction. For example, there is a possibility that the marker 105 exists on the positive side in the z direction and that a magnetic noise source exists on the negative side in the z direction. Therefore, the term that decays exponentially in the z direction is not omitted.

[0119] Also, for example, by measurement, H ｉ (x, y, 0), and ∂ / ∂zH, which is the gradient of the i component of the magnetic field vector in the z direction. ｉ (x, y, z) | ｚ＝０ Using these, a(k ｘ , k ｙ ) and b(k ｘ , k ｙ ) are calculated as shown in the following equations (7) and (8), respectively.

[0120]

[0121]

[0122] In the above equations (7) and (8), f(k ｘ , k ｙ ) is H ｉ (x, y, 0) is the two-dimensional Fourier transform image of g(kｘ , k ｙ ) is ∂ / ∂zH ｉ (x, y, z) | ｚ＝０ By substituting equations (7) and (8) into equation (2), H ｉ (x, y, z) is obtained as in the following equation (9).

[0123]

[0124] As described above, Equation (9) showing the magnetic field (specifically, the i component of the magnetic field vector) is derived according to the magnetic sensing results and the basic equations of the stationary magnetic field and quasi-stationary magnetic field in free space.

[0125] In other words, the Dirichlet boundary condition H ｉ (x, y, 0), and the Neumann boundary condition ∂ / ∂zH ｉ (x, y, z) | ｚ＝０ It is possible to derive a solution to the Laplace equation, which is the fundamental equation for the steady magnetic field and quasi-steady magnetic field in the free space, by using H ｉ (x, y, z) can be derived. That is, it is possible to reconstruct the magnetic field in the reconstruction plane close to the marker 105 from the magnetic fields in the measurement plane, which is the xy plane where z=0, and the measurement planes in the vicinity of the measurement plane.

[0126] For example, H ｉ (x, y, 0) is obtained as the sensing result on the measurement plane at z = 0. ∂ / ∂zH ｉ (x, y, z) | ｚ＝０ is calculated according to the sensing results on the two measurement planes. For example, the sensing result on the measurement plane at z=0 and the sensing result on the measurement plane at z=d are obtained, and the difference between them is divided by d, which is the distance between the measurement planes, to obtain ∂ / ∂zH ｉ (x, y, z) | ｚ＝０ is obtained approximately.

[0127] Then, the H obtained from the sensing result ｉ (x, y, 0) and ∂ / ∂zH ｉ (x, y, z) | ｚ＝０By performing a two-dimensional Fourier transform on f(k ｘ , k ｙ ), and g(k ｘ , k ｙ ) is obtained by two-dimensional Fourier transform. ｘ , k ｙ ), g(k ｘ , k ｙ ), and the z-coordinate value z of the reconstruction plane ａ By substituting into equation (9), H on the reconstruction surface ｉ (x, y, z ａ ) is obtained. This makes it possible to accurately obtain information about the magnetic field on the reconstruction plane.

[0128] Finally, H on the reconstruction surface ｉ (x, y, z ａ ) is expressed as the following equation (10).

[0129]

[0130] The information processing circuit 103 calculates an image showing the magnetic field on the reconstruction plane by calculating H in the above equation (10). ｉ (x, y, z ａ ) may be generated.

[0131] Fig. 13 is a block diagram showing the detailed configuration of the automatic driving control system 102 shown in Fig. 1. As described above, the automatic driving control system 102 includes the magnetic sensor array 104 and the information processing circuit 103.

[0132] The autonomous driving control system 102 may further include a driving controller 113. The driving controller 113 is a device for driving the vehicle 101, and is composed of a power source, an actuator, an electric circuit, etc. For example, the information processing circuit 103 may control the driving of the vehicle 101 via the driving controller 113 by transmitting a control signal for controlling the driving of the vehicle 101 to the driving controller 113.

[0133] The magnetic sensor array 104 includes a plurality of magnetic sensors 110. The information processing circuit 103 includes an input circuit 111 and an arithmetic circuit 112.

[0134] The input circuit 111 is an electric circuit for acquiring information and inputting the information to the arithmetic circuit 112. For example, the input circuit 111 acquires magnetic sensing results from the magnetic sensor array 104. Specifically, the input circuit 111 acquires magnetic sensing results from each magnetic sensor 110 that constitutes the magnetic sensor array 104. Then, the input circuit 111 inputs the magnetic sensing results to the arithmetic circuit 112.

[0135] The input circuit 111 may perform AD conversion (analog-to-digital conversion). For example, the input circuit 111 may acquire the magnetic sensing result from the magnetic sensor array 104 as an analog signal. Then, the input circuit 111 may convert the sensing result acquired as an analog signal into a digital signal. Then, the input circuit 111 may input the sensing result converted into a digital signal to the arithmetic circuit 112.

[0136] The arithmetic circuit 112 is an electric circuit for performing arithmetic processing. For example, the arithmetic circuit 112 performs the arithmetic processing described above. Specifically, the arithmetic circuit 112 calculates the magnetic field on the reconstruction plane from the magnetic field on the measurement plane, and generates an image showing the magnetic field on the reconstruction plane. Then, the arithmetic circuit 112 may transmit a control signal to the driving controller 113 to control the driving of the vehicle 101 according to the generated image.

[0137] 14 is a conceptual diagram showing the marker 105, a measurement image, and a reconstructed image in this embodiment. The marker 105 includes multiple magnetic poles, such as one or more north poles and one or more south poles. The magnetic sensor array 104 senses the magnetism of the magnetic field, including the magnetic field component induced by the marker 105. The sensing result is obtained as a measurement image.

[0138] However, the magnetic sensor array 104 is placed in a position where it will not collide with the road surface, and is therefore separated from the markers 105 installed on the road. Therefore, the magnetic poles of the markers 105 do not appear clearly in the measurement image.

[0139] The information processing circuit 103 generates a reconstructed image showing the magnetic field in a region closer to the marker 105 than the magnetic sensor array 104, based on the magnetic sensing results and the fundamental equations for stationary and quasi-stationary magnetic fields. Such a reconstructed image clearly shows the magnetic poles of the marker 105. Therefore, the information processing circuit 103 can appropriately identify the marker 105 according to the reconstructed image.

[0140] Fig. 15 is a conceptual diagram showing a first example of the marker 105. For example, in Fig. 15, the black part is the north pole part of the marker 105. The white part is the part of the marker 105 other than the north pole. In other words, the white part is the south pole part of the marker 105, or the part of the marker 105 that is neither the north pole nor the south pole. In this explanation, the north pole and the south pole may be interchanged.

[0141] 15 , the magnetic poles of the marker 105 may form a barcode. The marker 105 may use the barcode to represent a code string for controlling the running of the vehicle 101. This allows various pieces of information for controlling the running of the vehicle 101 to be expressed.

[0142] Fig. 16 is a conceptual diagram showing a second example of the marker 105. For example, similar to the example of Fig. 15, in Fig. 16, the black part is the north pole part of the marker 105, and the white part is the part other than the north pole of the marker 105. In this explanation, the north pole and south pole may be interchanged.

[0143] 16 , the magnetic poles of the marker 105 may form a two-dimensional code such as a QR code (registered trademark). The marker 105 may use the two-dimensional code to represent a code sequence for controlling the running of the vehicle 101. This allows a wider variety of information to be expressed.

[0144] For example, the marker 105 may represent four types of control, i.e., go straight, turn right, turn left, and stop, using two bits. Each bit may be represented by a section of the north or south pole of the marker 105. However, noise may be generated by manholes, fallen objects, etc. Therefore, the marker 105 may represent these controls using more bits.

[0145] Furthermore, the magnetic sensor array 104 is placed about 50 cm away from the road surface (for example, on the bottom of a typical vehicle) so as not to collide with the road surface. In other words, the magnetic sensor array 104 is placed about 50 cm away from the marker 105. The information processing circuit 103 generates a reconstructed image that shows the magnetic field on a reconstruction plane that is about 50 cm below the magnetic sensor array 104 in the up-down direction of the vehicle 101.

[0146] However, the magnetic field components induced by the marker 105 become more diffused as they move away from the marker 105, resulting in a decrease in the contrast of the measured image, which may result in an inappropriate reconstructed image.

[0147] Therefore, when the magnetic sensor array 104 is about 50 cm away from the marker 105, in order to obtain appropriate measurement images and reconstructed images, the north and south poles of the marker 105 should have a width of about 10 cm. In other words, each section of the barcode or two-dimensional code of the marker 105 should have a width of 10 cm or more.

[0148] For example, the barcode or two-dimensional code of the marker 105 has a size corresponding to the value obtained by multiplying the above width by the number of bits for representing the control of the vehicle 101 .

[0149] Furthermore, it is desirable that at least one of the markers 105 be located below the vehicle 101 so that the vehicle 101 does not deviate from the line of the markers 105. Therefore, it is desirable that the markers 105 be arranged at intervals shorter than the length of the vehicle 101 in the longitudinal direction of the vehicle 101 (for example, 5 m).

[0150] FIG. 17 is a conceptual diagram showing a third example of the marker 105. In this example, a magnetic wire is used as the marker 105. For example, the magnetic wire is a ferrite rope that induces a magnetic field component. Specifically, the magnetic wire may be installed along a road as the marker 105. The information processing circuit 103 may then cause the vehicle 101 to travel along the magnetic wire, thereby causing the vehicle 101 to travel along the road. This appropriately prevents the vehicle 101 from deviating from the road.

[0151] 18 is a conceptual diagram showing the magnetic field around the magnetic wire used as the marker 105. The magnetic wire is polarized in the width direction of the magnetic wire, with the north and south poles sandwiching the central axis of the magnetic wire.

[0152] Fig. 19 is an image diagram showing a reconstructed image when a magnetic wire is used as the marker 105. For example, the magnetic sensor array 104 is a one-dimensional magnetic sensor array, and is arranged along the arrangement direction shown in Fig. 19 and moves along the running direction shown in Fig. 19. Then, the reconstructed image is generated by the information processing circuit 103 as an image showing the magnetic field near the marker 105. In the reconstructed image of Fig. 19, the white parts correspond to the north poles and the black parts correspond to the south poles.

[0153] As shown in the reconstructed image of Fig. 19, a portion corresponding to the north pole of the magnetic wire and a portion corresponding to the south pole of the magnetic wire are observed. That is, the reconstructed image of Fig. 19 clearly shows the magnetic field around the magnetic wire used as the marker 105. Therefore, the running of the vehicle 101 is appropriately controlled.

[0154] Fig. 20 is a conceptual diagram showing a fourth example of the marker 105. In this example, a concentric marker 105 is used. That is, the marker 105 has concentric magnetic poles. For example, magnetic wires are arranged in circles with radii of 5 cm, 10 cm, and 15 cm and fixed by a support member. As shown in Fig. 20, positions where the magnetic wires can be arranged are defined as K, L, and M. The magnetic pattern of the marker 105 is determined depending on which of K, L, and M the magnetic wires are actually arranged at.

[0155] The magnetic wires may be arranged in one, two, or three of K, L, and M. That is, the magnetic wires may be arranged in K, L, M, KL, KM, LM, or KLM. Thus, seven magnetic patterns can be used.

[0156] 21 is a conceptual diagram showing the direction of the magnetic field around the concentric marker 105. For example, when the marker 105 is installed on a road, the magnetic wire is arranged so that the magnetic field direction points upward from the marker 105. Specifically, the magnetic wire is arranged so that the north pole is on the upper side.

[0157] The magnetic wire may be arranged so that the south pole is on the top, or so that the south pole is on the inside and the north pole is on the outside, or so that the north pole is on the inside and the south pole is on the outside.

[0158] For example, by standardizing all of K, L, and M so that one of the north and south poles is on the upper side, it becomes easier to identify the magnetic patterns.

[0159] Fig. 22 is an image diagram showing a reconstructed image when concentric markers 105 are used. For each of the magnetic wire arrangement positions K, L, M, KL, KM, LM, and KLM, a reconstructed image as shown in Fig. 22 is generated by the information processing circuitry 103. In the reconstructed image in Fig. 22, the white parts correspond to the north poles and the black parts correspond to the south poles.

[0160] 22, a reconstructed image corresponding to each magnetic pattern is generated. Therefore, the information processing circuit 103 can appropriately identify the magnetic pattern based on the reconstructed image, and can appropriately control the traveling of the vehicle 101 based on the magnetic pattern. Furthermore, the information processing circuit 103 can appropriately identify the magnetic pattern regardless of the orientation of the vehicle 101, and can appropriately read control information such as a right turn, left turn, or straight ahead indicated by the magnetic pattern.

[0161] Although three circles are used here, two or fewer circles may be used, or four or more circles may be used. The number of circles determines the number of magnetic patterns and the number of types of control.

[0162] 23 is a conceptual diagram showing a fifth example of the marker 105. In this example, an electrical conductor is used as the marker 105. For example, the electrical conductor used as the marker 105 is a closed circuit made of a metal such as copper. An annular (ring-shaped) electrical conductor may be used as the marker 105, or a coil-shaped electrical conductor may be used as the marker 105.

[0163] The marker 105, which is an electrical conductor, induces a magnetic field component by electromagnetic induction. The vehicle 101 is equipped with an induction circuit for generating electromagnetic induction.

[0164] 24 is a conceptual diagram showing an induction circuit mounted on the vehicle 101. As shown in FIG. 24 , the induction circuit 114 mounted on the vehicle 101 may be a coil connected to a power source 115. Furthermore, the induction circuit 114 mounted on the vehicle 101 may include the power source 115. Furthermore, the induction circuit 114 may be arranged so as to cover the magnetic sensor array 104 composed of a plurality of magnetic sensors 110.

[0165] For example, when a current flows in the induction circuit 114, the induction circuit 114 induces a downward first magnetic field component below the vehicle 101. This generates electromagnetic induction, causing a current to flow in the marker 105, which is an electrical conductor, and the marker 105 induces an upward second magnetic field component. The magnetic sensor array 104 senses the magnetism of the magnetic field including the second magnetic field component.

[0166] This allows the autonomous driving control system 102 to sense the magnetism of the magnetic field, including the magnetic field component induced by the marker 105. The autonomous driving control system 102 can then generate an image showing the magnetic field in the area close to the marker 105 and appropriately control the driving of the vehicle 101 in accordance with the image.

[0167] For example, the magnetic poles of a permanent magnet such as a ferrite magnet may be altered by a strong external magnetic field. In other words, if the marker 105 is a permanent magnet such as a ferrite magnet, the magnetic pattern may be altered by a strong external magnetic field. On the other hand, if the marker 105 is an electrical conductor such as copper, the magnetism is appropriately controlled by electromagnetic induction, thereby suppressing adverse effects such as alteration of the magnetic pattern.

[0168] Furthermore, for example, the marker 105, which is an electrical conductor, has a magnetic pattern corresponding to the shape of the electrical conductor. By having a plurality of shapes, the markers 105 may emit a steady magnetic field or a quasi-steady magnetic field with a plurality of magnetic patterns.

[0169] Also, for example, in vehicle 101, the information processing circuit 103 of the automatic driving control system 102 may switch between an operation corresponding to an electrical conductor and an operation corresponding to a permanent magnet by switching whether or not to apply current to the induction circuit 114.

[0170] 25 is a conceptual diagram showing another example of an electrical conductor used as the marker 105. The electrical conductor used as the marker 105 is not limited to an annular electrical conductor, but may be a metal disk or the like. Even when the electrical conductor is a metal disk, eddy currents are generated within the metal disk due to electromagnetic induction. This induces a magnetic field component.

[0171] Specifically, as in the example of Figure 24, for example, a current flowing in the induction circuit 114 of the vehicle 101 induces a downward first magnetic field component. This causes electromagnetic induction, which causes eddy currents to flow in the metal disc, causing the metal disc to induce an upward second magnetic field component. The magnetic sensor array 104 senses the magnetic field including the second magnetic field component. This allows the autonomous driving control system 102 to sense the magnetic field including the magnetic field component induced by the metal disc installed as the marker 105.

[0172] Fig. 26 is a conceptual diagram showing yet another example of an electrical conductor used as the marker 105. As shown in Fig. 26, the electrical conductor used as the marker 105 may be a coil-shaped closed circuit. Note that the electrical conductor used as the marker 105 does not need to be connected to a power source or include a power source.

[0173] In the examples of the marker 105 shown in FIGS. 15 to 22, an electrically conductive material may be used instead of the magnetic material.

[0174] For example, in the example of Fig. 15, there may be coils in the black portions and no coils in the white portions. Alternatively, in the example of Fig. 15, there may be no coils in the black portions and coils in the white portions. Similarly, in the example of Fig. 16, there may be coils in the black portions and no coils in the white portions. Alternatively, in the example of Fig. 16, there may be no coils in the black portions and coils in the white portions. Even if an electrical conductor is used, the control and the like described with reference to Figs. 15 and 16 can be applied.

[0175] Fig. 27 is a conceptual diagram schematically illustrating an example of an electrical conductor corresponding to the example of Fig. 15. For example, a closed circuit of an electrical conductor as shown in Fig. 27 may be arranged along the outline of the black portion (or white portion) shown in the example of Fig. 15.

[0176] Fig. 28 is a conceptual diagram schematically illustrating an example of an electrical conductor corresponding to the example of Fig. 16. For example, a closed circuit of an electrical conductor as shown in Fig. 28 may be arranged along the outline of the black portion (or white portion) shown in the example of Fig. 16.

[0177] Fig. 29 is a conceptual diagram schematically illustrating another example of an electrical conductor corresponding to the example of Fig. 15. For example, a plate of electrical conductor may be placed in the black portion (or white portion) shown in the example of Fig. 15, as shown in Fig. 29. That is, a plate-shaped electrical conductor may be used instead of the annular electrical conductor shown in Fig. 27. As described above, even when a plate-shaped electrical conductor is used, eddy currents are generated in the electrical conductor by electromagnetic induction, and magnetic field components are induced from the electrical conductor. This results in the formation of a barcode-shaped magnetic pattern.

[0178] Fig. 30 is a conceptual diagram schematically illustrating another example of an electrical conductor corresponding to the example of Fig. 16. For example, a plate of electrical conductor may be arranged in the black (or white) portion shown in the example of Fig. 16, as shown in Fig. 30. That is, a plate-shaped electrical conductor may be used instead of the annular electrical conductor shown in Fig. 28. As described above, even when a plate-shaped electrical conductor is used, eddy currents are generated in the electrical conductor by electromagnetic induction, and magnetic field components are induced from the electrical conductor. This results in the formation of a two-dimensional code-like magnetic pattern.

[0179] Also, a wire-like electric conductor may be used instead of the magnetic wire shown in Figures 17 to 19. In this case, the control etc. described in Figures 17 to 19 can also be applied.

[0180] Also, concentric electrically conductive materials may be used instead of the concentric magnetic materials shown in Figures 20 to 22. In this case, the control and the like described in Figures 20 to 22 can also be applied.

[0181] 31 is a conceptual diagram showing a first specific example of the magnetic sensor array 104 shown in FIG. 1. In this example, the multiple magnetic sensors 110 of the magnetic sensor array 104 are arranged on two planes that are parallel to both the longitudinal and lateral directions of the vehicle 101 and correspond to two different positions in the vertical direction of the vehicle 101. Specifically, in this example, two two-dimensional magnetic sensor arrays are stacked on top of each other. This allows magnetic sensing results to be obtained on two measurement surfaces, which are two planes.

[0182] Fig. 32 is a conceptual diagram showing a second specific example of the magnetic sensor array 104 shown in Fig. 1. In this example, as in the example of Fig. 31, the multiple magnetic sensors 110 of the magnetic sensor array 104 are arranged on two planes that are parallel to both the longitudinal and lateral directions of the vehicle 101 and correspond to two different positions in the up-down direction of the vehicle 101. In this example, the multiple magnetic sensors 110 are arranged alternately on the two planes with respect to each of the longitudinal and lateral directions of the vehicle 101.

[0183] This allows for the acquisition of magnetic sensing results on two flat measurement surfaces. Furthermore, in this example, the misalignment of the multiple magnetic sensors 110 arranged on the two planes in the front-rear and left-right directions may be ignored. Alternatively, the sensing results may be interpolated by linear interpolation in the front-rear and left-right directions. Alternatively, the magnetic sensor array 104 may move in accordance with the movement of the vehicle 101, causing magnetic sensing at positions on the two measurement surfaces that correspond to the same positions in the front-rear and left-right directions.

[0184] Fig. 33 is a conceptual diagram showing a third specific example of the magnetic sensor array 104 shown in Fig. 1. In this example, as in the example of Fig. 31, the multiple magnetic sensors 110 of the magnetic sensor array 104 are arranged on two planes that are parallel to both the longitudinal and lateral directions of the vehicle 101 and correspond to two different positions in the vertical direction of the vehicle 101. In this example, the multiple magnetic sensors 110 are arranged alternately on the two planes with respect to the longitudinal direction of the vehicle 101.

[0185] This allows for the acquisition of magnetic sensing results on two flat measurement surfaces. Furthermore, in this example, the longitudinal misalignment of the multiple magnetic sensors 110 arranged on the two planes may be ignored. Alternatively, the sensing results may be interpolated by linear interpolation in the longitudinal direction. Alternatively, the magnetic sensor array 104 may move in accordance with the movement of the vehicle 101, causing magnetic sensing at positions on the two measurement surfaces that correspond to the same positions in the longitudinal and lateral directions.

[0186] In this example, the multiple magnetic sensors 110 are arranged alternately on two planes in the longitudinal direction of the vehicle 101, but the multiple magnetic sensors 110 may also be arranged alternately on two planes in the lateral direction of the vehicle 101. In this case, magnetic sensing results are obtained on two measurement surfaces, which are two planes. In this case, the lateral deviation of the multiple magnetic sensors 110 arranged on the two planes may be ignored. Alternatively, the sensing results may be interpolated by linear interpolation in the lateral direction, for example.

[0187] 34 is a conceptual diagram showing a fourth specific example of the magnetic sensor array 104 shown in FIG. 1. In this example, the multiple magnetic sensors 110 of the magnetic sensor array 104 are arranged on a single plane that is parallel to both the longitudinal and lateral directions of the vehicle 101. Specifically, in this example, a single two-dimensional magnetic sensor array is used. This allows for the acquisition of magnetic sensing results on a single measurement surface, which is a single plane.

[0188] Note that the magnetic sensor array 104 in this example may sense magnetism on two measurement surfaces by vibrating in the vertical direction of the vehicle 101. An actuator that vibrates the magnetic sensor array 104 in the vertical direction of the vehicle 101 may be mounted on the vehicle 101. The autonomous driving control system 102 may be equipped with such an actuator.

[0189] 35 is a conceptual diagram showing a fifth specific example of the magnetic sensor array 104 shown in Fig. 1. In this example, the multiple magnetic sensors 110 of the magnetic sensor array 104 are arranged on two straight lines that are parallel to the left-right direction of the vehicle 101 and correspond to two different positions in the up-down direction of the vehicle 101. In this example, the two straight lines on which the multiple magnetic sensors 110 are arranged correspond to the same single position in the front-rear direction of the vehicle 101. Specifically, two one-dimensional magnetic sensor arrays are stacked on top of each other.

[0190] As the vehicle 101 moves in the longitudinal direction, the magnetic sensors 110 also move, thereby obtaining magnetic sensing results on two measurement surfaces that correspond to two different positions in the vertical direction of the vehicle 101.

[0191] 36 is a conceptual diagram showing a sixth specific example of the magnetic sensor array 104 shown in Fig. 1. In this example, too, the multiple magnetic sensors 110 of the magnetic sensor array 104 are arranged on two straight lines that are parallel to the left-right direction of the vehicle 101 and correspond to two different positions in the up-down direction of the vehicle 101. Also in this example, too, the two straight lines on which the multiple magnetic sensors 110 are arranged correspond to the same single position in the front-rear direction of the vehicle 101.

[0192] In this example, the multiple magnetic sensors 110 are arranged alternately on two straight lines in the left-right direction of the vehicle 101. As the vehicle 101 moves in the forward-backward direction, the multiple magnetic sensors 110 also move. As a result, magnetic sensing results are obtained on two measurement surfaces corresponding to two different positions in the up-down direction of the vehicle 101.

[0193] In this example, the deviation in the left-right direction of the multiple magnetic sensors 110 arranged on two straight lines may be ignored. Alternatively, the sensing results may be interpolated by linear interpolation in the left-right direction.

[0194] Fig. 37 is a conceptual diagram showing a seventh specific example of the magnetic sensor array 104 shown in Fig. 1. In this example, too, the multiple magnetic sensors 110 of the magnetic sensor array 104 are arranged on two straight lines that are parallel to the left-right direction of the vehicle 101 and correspond to two different positions in the up-down direction of the vehicle 101.

[0195] In this example, the two straight lines on which the multiple magnetic sensors 110 are arranged correspond to two different positions in the longitudinal direction of the vehicle 101. As the vehicle 101 moves in the longitudinal direction, the multiple magnetic sensors 110 also move. As a result, magnetic sensing results are obtained on two measurement surfaces that respectively correspond to two different positions in the vertical direction of the vehicle 101.

[0196] In this example, the longitudinal deviation of the multiple magnetic sensors 110 arranged on two straight lines may be ignored. Alternatively, the magnetic sensor array 104 may move in accordance with the movement of the vehicle 101, so that magnetism may be sensed at positions corresponding to the same positions in the longitudinal and lateral directions on the two measurement planes.

[0197] 38 is a conceptual diagram showing an eighth specific example of the magnetic sensor array 104 shown in FIG. 1. In this example, the multiple magnetic sensors 110 of the magnetic sensor array 104 are arranged on a single straight line parallel to the left-right direction of the vehicle 101. Specifically, in this example, a single one-dimensional magnetic sensor array is used. As the vehicle 101 moves in the forward-backward direction, the multiple magnetic sensors 110 also move. This allows for the acquisition of magnetic sensing results on a single measurement plane corresponding to a single position in the up-down direction of the vehicle 101.

[0198] Note that the magnetic sensor array 104 in this example may sense magnetism on two measurement surfaces by vibrating in the vertical direction of the vehicle 101. An actuator that vibrates the magnetic sensor array 104 in the vertical direction of the vehicle 101 may be mounted on the vehicle 101. The autonomous driving control system 102 may be equipped with such an actuator.

[0199] 31 to 38, the up-down direction in each figure corresponds to the up-down direction of the vehicle 101, but the up-down direction may be reversed so that the magnetic sensors 110 are installed facing downward. Also, although multiple magnetic sensors 110 are shown schematically in Figures 31 to 38, the form of the multiple magnetic sensors 110 is not limited to the examples shown in Figures 31 to 38. In particular, the number of multiple magnetic sensors 110 is not limited to the number shown in Figures 31 to 38.

[0200] 31 to 33 can be considered as a combination of two two-dimensional magnetic sensor arrays aligned along the longitudinal and lateral directions of the vehicle 101. The two two-dimensional magnetic sensor arrays are respectively arranged at two different positions in the vertical direction of the vehicle 101.

[0201] 35 to 37 can be considered as a combination of two one-dimensional magnetic sensor arrays arranged along the left-right direction of the vehicle 101. The two one-dimensional magnetic sensor arrays are arranged at two different positions in the up-down direction of the vehicle 101.

[0202] 39 is a conceptual diagram showing a magnetic shield mounted on the vehicle 101. When the magnetic sensor array 104 does not sense magnetism in two measurement planes but senses magnetism in one measurement plane, the information processing circuit 103 generates a reconstructed image using the above-mentioned equation (5). However, in this case, there is a possibility that the reconstructed image will not be generated properly due to a magnetic noise source above the magnetic sensor array 104.

[0203] 39 , a magnetic shield 116 may be installed above the magnetic sensor array 104. For example, the magnetic shield 116 is made of permalloy, which has high magnetic permeability. The magnetic shield 116 makes it difficult for magnetic fields from a magnetic noise source above the magnetic shield 116 to reach the magnetic sensor array 104 below the magnetic shield 116. This allows a reconstructed image to be generated appropriately even when a magnetic noise source exists above the magnetic sensor array 104.

[0204] The magnetic shield 116 is particularly effective when the magnetic sensor array 104 does not sense magnetism in two measurement planes but senses magnetism in one measurement plane. However, the magnetic shield 116 may be used even when the magnetic sensor array 104 senses magnetism in two measurement planes. The autonomous driving control system 102 may also be equipped with such a magnetic shield 116.

[0205] 40 is a flowchart showing the driving control process performed by the information processing circuit 103. For example, the information processing circuit 103 reads the magnetic sensing result from the magnetic sensor array 104 (S201).

[0206] Next, the information processing circuit 103 generates a reconstructed image of a region near the estimated position of the marker 105 based on the magnetic sensing result and the fundamental equations of stationary and quasi-stationary magnetic fields. The information processing circuit 103 then correlates the reconstructed image with a magnetic pattern stored in memory and determines whether the correlation value is greater than or equal to a threshold (S202). If the correlation value is less than the threshold (No in S202), it is assumed that the magnetism of the marker 105 has not been sensed. In this case, the information processing circuit 103 stops the vehicle 101 (S207).

[0207] If the correlation value is equal to or greater than the threshold value (Yes in S202), it is assumed that the magnetism of the marker 105 is being sensed. In this case, the information processing circuit 103 determines the position corresponding to the correlation value equal to or greater than the threshold value (S203). In other words, the information processing circuit 103 determines the position of the portion in the reconstructed image where a correlation value equal to or greater than the threshold value is obtained for the magnetic pattern prepared in the memory.

[0208] If the position corresponding to the correlation value equal to or greater than the threshold is a left position, the information processing circuit 103 causes the vehicle 101 to turn left (S204). If the position corresponding to the correlation value equal to or greater than the threshold is a center position, the information processing circuit 103 causes the vehicle 101 to go straight (S205). If the position corresponding to the correlation value equal to or greater than the threshold is a right position, the information processing circuit 103 causes the vehicle 101 to turn right (S206).

[0209] The information processing circuit 103 repeats the above processing (S201 to S207), thereby enabling the information processing circuit 103 to control the running of the vehicle 101 in accordance with the reconstructed image.

[0210] The above-described driving control process is merely an example, and various modifications may be made. For example, the sensing results may be read in advance in a steady magnetic field or a quasi-steady magnetic field. In subsequent operations, the difference between the sensing results in the steady magnetic field and the results obtained in the steady magnetic field may be used. This may reduce the influence of individual differences among the multiple magnetic sensors 110 and the influence of the environmental magnetic field.

[0211] Furthermore, the information processing circuit 103 may control the curvature for making the vehicle 101 turn left or right depending on the position corresponding to a correlation value equal to or greater than a threshold. For example, the information processing circuit 103 may increase the curvature as the position corresponding to a correlation value equal to or greater than a threshold moves away from the center. This allows the information processing circuit 103 to make the vehicle 101 travel along various curves.

[0212] The information processing circuit 103 may also use P control (ratio control) to control the running of the vehicle 101. The information processing circuit 103 may also use I control (integral control) on curves to make the vehicle 101 run smoothly along curves.

[0213] Next, a basic experiment related to this embodiment will be described with reference to Figures 41 to 44. In this basic experiment, a reconstructed image is generated from a measurement image.

[0214] Fig. 41 is a conceptual diagram of a basic experiment (an experiment with a reduced scale), which shows two measurement planes and a reconstruction plane in an xyz orthogonal coordinate system.

[0215] z is the coordinate value in the z direction from the measurement surface toward the magnetic source, x is the coordinate value in the x direction perpendicular to the z direction, and y is the coordinate value in the y direction perpendicular to the z and x directions.

[0216] The magnetic source is three ferrite magnets spaced 2 cm apart. The reconstruction plane is z = 1.7 mm, corresponding to the position where the magnetic source is located. The two measurement planes are z = 0 mm and z = 0.2 mm, and magnetic fields are sensed in both measurement planes.

[0217] Fig. 42 is an image diagram showing a first measurement image obtained in a basic experiment (a reduced-scale experiment). Specifically, Fig. 42 shows the first measurement image corresponding to the magnetic sensing result on the measurement surface at z = 0 mm.

[0218] Fig. 43 is an image diagram showing a second measurement image obtained in a basic experiment (a reduced-scale experiment). Specifically, Fig. 43 shows a second measurement image corresponding to the magnetic sensing result on the measurement surface at z = 0.2 mm.

[0219] Fig. 44 is an image diagram showing a reconstructed image obtained in a basic experiment (a reduced-scale experiment). Specifically, Fig. 44 shows a reconstructed image showing the magnetic field on the reconstruction plane at z = 1.7 mm. This reconstructed image is generated using Equation (9).

[0220] In the first and second measurement images shown in Figures 42 and 43, it is difficult to identify the presence of the three ferrite magnets. On the other hand, in the reconstructed image shown in Figure 44, it is possible to identify the presence of the three ferrite magnets. In other words, the reduction experiment showed that the reconstructed image can properly show the magnetic field in an area closer to the magnetic source than the measurement surface. By using such a reconstructed image, the autonomous driving control system 102 can properly identify the marker 105 and properly control the traveling of the vehicle 101.

[0221] Next, verification related to this embodiment will be described with reference to Figures 45 to 48. This verification is a comparative verification between control based on a measurement image and control based on a reconstructed image.

[0222] Fig. 45 is a conceptual diagram showing the relationship between a measurement image and a reconstructed image for verification. Specifically, Fig. 45 shows the magnetic field distribution on the surface of the marker 105, a measurement image showing the magnetic sensing result of the magnetic sensor array 104, and a reconstructed image obtained by the information processing circuit 103 as an image showing the magnetic field in a region close to the marker 105.

[0223] The measured image corresponds to the magnetic sensing results of the magnetic sensor array 104 that is distant from the marker 105, and therefore deviates from the magnetic field distribution on the surface of the marker 105. On the other hand, the reconstructed image is an image obtained according to the basic equations of steady magnetic fields and quasi-steady magnetic fields, and shows the magnetic field in the area close to the marker 105 on the road on which the marker 105 is installed, and therefore approximates the magnetic field distribution on the surface of the marker 105. In other words, the reconstructed image appropriately shows the magnetic pattern of the marker 105.

[0224] Therefore, it is expected that the automatic driving control system 102 can more appropriately control the driving of the vehicle 101 by using the reconstructed image rather than the measured image.

[0225] To compare and verify control based on the measured image and control based on the reconstructed image, a prototype model of a vehicle 101 equipped with an autonomous driving control system 102 and a plurality of markers 105 is used in an indoor environment. In addition, a plurality of tracked markers, each of which is a tracked marker 105, and a plurality of dummy markers, each of which is a dummy marker 105, are placed in the indoor environment.

[0226] Then, in each of the control based on the measurement image and the control based on the reconstructed image, it is verified whether the vehicle 101 can continue to track only the plurality of tracking target markers among the plurality of markers 105.

[0227] 46 is a conceptual diagram showing a tracking target marker. The tracking target marker has a two-dimensional code-like magnetic pattern. In other words, the tracking target marker has a matrix-like magnetic pattern, and each of the multiple sections included in the magnetic pattern corresponds to a north pole, a south pole, or a non-magnetic pole that is neither north nor south.

[0228] Fig. 47 is a conceptual diagram showing dummy markers. As shown in Fig. 47, four types of dummy markers are used for verification.

[0229] Like the tracking target markers, the dummy markers also have a matrix-like magnetic pattern, and each of the multiple sections included in the magnetic pattern corresponds to a north pole, a south pole, or a non-magnetic pole. The four types of dummy markers have four different magnetic patterns. The four types of magnetic patterns of the four types of dummy markers are also different from the magnetic patterns of the tracking target markers.

[0230] Fig. 48 is a graph showing the results of a comparison between control based on measured images and control based on reconstructed images. In Fig. 48, the recognition error is the difference between the position of the tracked marker recognized by the autonomous driving control system 102 and the actual position of the tracked marker. In control based on measured images, the recognition error is relatively large, and the vehicle 101 is unable to track the tracked marker midway through. On the other hand, in control based on reconstructed images, the recognition error is relatively small, and the vehicle 101 is able to continue tracking the tracked marker until the end.

[0231] That is, the automatic driving control system 102 can control the traveling of the vehicle 101 more appropriately by using the reconstructed image rather than the measured image.

[0232] As described above, the autonomous driving control system 102 for the vehicle 101 traveling on a road on which the marker 105 is installed includes the magnetic sensor array 104 and the information processing circuit 103. The magnetic sensor array 104 is mounted on the vehicle 101 and senses magnetism. The information processing circuit 103 generates an image showing the magnetic field in a region closer to the marker 105 than the magnetic sensor array 104, based on the magnetic sensing results and the fundamental equations of steady-state magnetic fields and quasi-steady magnetic fields. The information processing circuit 103 then controls the traveling of the vehicle 101 in accordance with the image.

[0233] This allows the autonomous driving control system 102 to control the traveling of the vehicle 101 in accordance with an image that shows the magnetic field in an area closer to the marker 105 than the magnetic sensor array 104. This image is expected to show the marker 105 with high accuracy. Therefore, it is expected that the marker 105 will be properly identified. Therefore, the autonomous driving control system 102 can properly control the traveling of the vehicle 101 in accordance with the marker 105.

[0234] For example, the information processing circuit 103 may acquire the speed of the vehicle 101. Then, the information processing circuit 103 may convert the temporal change of the sensing result into a spatial change according to the speed. Then, the information processing circuit 103 may generate an image showing the magnetic field according to the sensing result in which the temporal change is converted into a spatial change and the fundamental equation.

[0235] This allows the autonomous driving control system 102 to fully capture the temporal changes in the sensing results and the spatial changes in the magnetic field according to the speed of the vehicle 101. Therefore, the autonomous driving control system 102 can appropriately generate an image showing the magnetic field.

[0236] Furthermore, for example, the magnetic sensor array 104 may be configured with one or more two-dimensional magnetic sensor arrays aligned along the longitudinal and lateral directions of the vehicle 101. This allows the autonomous driving control system 102 to adequately acquire spatial variations in the magnetic field using the two-dimensional magnetic sensor arrays. Therefore, the autonomous driving control system 102 can appropriately generate an image showing the magnetic field.

[0237] Furthermore, for example, the magnetic sensor array 104 may be configured with one or more one-dimensional magnetic sensor arrays arranged along the left-right direction of the vehicle 101. This allows the autonomous driving control system 102 to appropriately control the traveling of the vehicle 101 with fewer resources and at low cost.

[0238] Furthermore, for example, the magnetic sensor array 104 may sense magnetism in one layer along the longitudinal and lateral directions of the vehicle 101. This allows the autonomous driving control system 102 to simply sense magnetism and perform processing with a low amount of calculation.

[0239] Furthermore, for example, the magnetic sensor array 104 may sense magnetism in two layers along the longitudinal direction and the lateral direction of the vehicle 101. This allows the autonomous driving control system 102 to properly obtain the gradient of the magnetic field in the vertical direction and properly generate an image showing the magnetic field.

[0240] Furthermore, for example, the information processing circuitry 103 may generate an image in accordance with the above-mentioned equation (5) as an arithmetic expression that follows the sensing result and the fundamental equation.

[0241] In the above formula (5), H ｉ (x, y, z) indicates the i component of the magnetic field at the coordinate position (x, y, z). i indicates x, y, or z. z indicates the coordinate value in the z direction, which is from top to bottom of the vehicle 101. x indicates the coordinate value in the x direction, which is perpendicular to the z direction. y indicates the coordinate value in the y direction, which is perpendicular to the z and x directions.

[0242] Also, f(k ｘ , k ｙ ) is H ｉ The two-dimensional Fourier transform image of (x, y, 0) is shown.ｉ (x, y, 0) indicates the sensing result at (x, y, 0), which is the measurement plane. ｘ indicates the wave number with respect to x. ｙ denotes the wave number with respect to y.

[0243] This allows the autonomous driving control system 102 to use the sensing results to appropriately generate an image showing the magnetic field in an area closer to the marker 105 than the magnetic sensor array 104.

[0244] Furthermore, for example, the information processing circuitry 103 may generate an image in accordance with the above-mentioned equation (9) as an arithmetic expression that follows the sensing result and the fundamental equation.

[0245] In the above formula (9), H ｉ (x, y, z) indicates the i component of the magnetic field at the coordinate position (x, y, z). i indicates x, y, or z. z indicates the coordinate value in the z direction, which is from top to bottom of the vehicle 101. x indicates the coordinate value in the x direction, which is perpendicular to the z direction. y indicates the coordinate value in the y direction, which is perpendicular to the z and x directions.

[0246] Also, f(k ｘ , k ｙ ) is H ｉ The two-dimensional Fourier transform image of (x, y, 0) is shown. ｉ (x, y, 0) indicates the sensing result at (x, y, 0), which is the measurement plane. ｘ , k ｙ ) is ∂ / ∂zH ｉ (x, y, z) | ｚ＝０ The two-dimensional Fourier transform image of ∂ / ∂zH is shown. ｉ (x, y, z) | ｚ＝０ denotes the gradient in the z direction of the sensing result at (x, y, 0), which is the measurement plane. ｘ indicates the wave number with respect to x. ｙ denotes the wave number with respect to y.

[0247] This allows the autonomous driving control system 102 to use the sensing results and their gradients to appropriately generate an image showing the magnetic field in an area closer to the marker 105 than the magnetic sensor array 104.

[0248] Furthermore, for example, the autonomous driving control system 102 may further include at least one of a camera, LiDAR, millimeter-wave radar, ultrasonic sonar, and a GPS receiver. Here, at least one of the camera, LiDAR, millimeter-wave radar, ultrasonic sonar, and GPS receiver is mounted on the vehicle 101. The information processing circuit 103 may further control the traveling of the vehicle 101 in accordance with at least one of the camera, LiDAR, millimeter-wave radar, ultrasonic sonar, and GPS receiver.

[0249] This allows the autonomous driving control system 102 to control the driving of the vehicle 101 according to various information obtained from the camera, LiDAR, millimeter wave radar, ultrasonic sonar, and GPS receiver.

[0250] Furthermore, for example, the autonomous driving control system 102 may further include markers 105 installed on the road. This allows the autonomous driving control system 102 to control the traveling of the vehicle 101 in accordance with the markers 105 included in the autonomous driving control system 102.

[0251] Furthermore, for example, the autonomous driving control system 102 may include a plurality of markers 105, each of which is installed on a road as a marker 105. The plurality of markers 105 may emit a steady magnetic field or a quasi-steady magnetic field with a plurality of magnetic patterns for controlling the traveling of the vehicle 101. This allows the autonomous driving control system 102 to control the traveling of the vehicle 101 in accordance with the plurality of magnetic patterns.

[0252] Furthermore, for example, each of the plurality of magnetic patterns may be a concentric magnetic pattern, which allows the autonomous driving control system 102 to suppress the influence of the orientation of the vehicle 101 in identifying the magnetic pattern.

[0253] Furthermore, for example, each of the plurality of magnetic patterns may be a barcode-like magnetic pattern, which allows the autonomous driving control system 102 to control the traveling of the vehicle 101 in accordance with the barcode that can simply indicate various pieces of information.

[0254] Furthermore, for example, each of the plurality of magnetic patterns may be a two-dimensional code-like magnetic pattern, which allows the autonomous driving control system 102 to control the traveling of the vehicle 101 in accordance with the two-dimensional code that can indicate a wider variety of information.

[0255] Furthermore, for example, the marker 105 may represent a code string for controlling the running of the vehicle 101 by using an arrangement of multiple magnetic poles. The code string may also include a code for error detection. The information processing circuit 103 may then read out the code string according to an image showing the magnetic field.

[0256] Furthermore, the information processing circuit 103 may determine whether the read code sequence contains an error according to the code contained in the read code sequence. If the information processing circuit 103 determines that the read code sequence does not contain an error, the information processing circuit 103 may control the running of the vehicle 101 according to the read code sequence.

[0257] This allows the autonomous driving control system 102 to read the code sequence from the marker 105 via the image showing the magnetic field. Furthermore, the autonomous driving control system 102 can determine whether the read code sequence contains an error according to the code for error detection. Therefore, the autonomous driving control system 102 can appropriately control the driving of the vehicle 101 according to the highly reliable code sequence.

[0258] Furthermore, for example, the marker 105 may have a wire-like shape, which allows the autonomous driving control system 102 to control the traveling of the vehicle 101 along the wire-like shape.

[0259] Furthermore, for example, the marker 105 may be a magnetic material, which allows the automatic driving control system 102 to control the traveling of the vehicle 101 using the simple marker 105.

[0260] Furthermore, for example, the marker 105 may be an electrically conductive conductor, which allows the autonomous driving control system 102 to appropriately control the traveling of the vehicle 101 by using the electrically conductive conductor as the marker 105.

[0261] Furthermore, for example, the autonomous driving control system 102 may further include an induction circuit 114. Here, the induction circuit 114 is mounted on the vehicle 101 and induces a first magnetic field component. The marker 105 may then induce a second magnetic field component by the first magnetic field component. This allows the autonomous driving control system 102 to appropriately generate a magnetic field from the marker 105 even when an electrical conductor is used as the marker 105.

[0262] Furthermore, for example, the vehicle 101 according to one aspect of the present disclosure may include the autonomous driving control system 102. This allows the vehicle 101 to control the traveling of the vehicle 101 in accordance with an image showing a magnetic field in an area closer to the marker 105 than the magnetic sensor array 104.

[0263] Although the aspects of the autonomous driving control system have been described above according to the embodiments, the aspects of the autonomous driving control system are not limited to the embodiments. Modifications conceivable by those skilled in the art may be applied to the embodiments, and multiple components in the embodiments may be combined in any manner.

[0264] For example, a process performed by a specific component in an embodiment may be performed by another component instead of the specific component. Furthermore, the order of multiple processes may be changed, or multiple processes may be performed in parallel. Furthermore, multiple modified examples may be combined and applied. Furthermore, ordinal numbers such as first and second used in the description may be changed as appropriate. Furthermore, new ordinal numbers may be assigned to components, or ordinal numbers may be removed.

[0265] Furthermore, an autonomous driving control method including steps performed by each component of the autonomous driving control system may be executed by any device or system. For example, a part or all of the autonomous driving control method may be executed by a computer including a processor, memory, input / output circuits, etc. In this case, the autonomous driving control method may be executed by the computer executing a program for causing the computer to execute the autonomous driving control method.

[0266] The above program may also be recorded on a non-transitory computer-readable recording medium.

[0267] Furthermore, each component of the autonomous driving control system may be configured with dedicated hardware, general-purpose hardware that executes the above-mentioned programs, or a combination of these. The general-purpose hardware may be configured with a memory in which the programs are recorded and a general-purpose processor that reads and executes the programs from the memory. Here, the memory may be a semiconductor memory or a hard disk, and the general-purpose processor may be a CPU.

[0268] Furthermore, the dedicated hardware may be configured with a memory, a dedicated processor, etc. For example, the dedicated processor may execute the above-described autonomous driving control method by referring to a memory for recording data.

[0269] Furthermore, each component of the autonomous driving control system may be an electric circuit. These electric circuits may form a single electric circuit as a whole, or may be separate electric circuits. These electric circuits may correspond to dedicated hardware, or may correspond to general-purpose hardware that executes the above-mentioned programs, etc.

[0270] The automatic driving control system may also be referred to as an automatic driving control device. The automatic driving control system may be configured with a plurality of devices that are distributed.

[0271] One aspect of the present disclosure is useful for an automatic driving control system for vehicles traveling on roads on which markers are installed, and is applicable to traffic systems, transportation systems, and the like.

[0272] REFERENCE SIGNS LIST 101 Vehicle 102 Autonomous driving control system 103 Information processing circuit 104 Magnetic sensor array 105 Marker 106 Camera 107 LiDAR 108 Wave sensor 109 GPS receiver 110 Magnetic sensor 111 Input circuit 112 Arithmetic circuit 113 Travel controller 114 Induction circuit 115 Power supply 116 Magnetic shield 117 Protective agent

Claims

1. An automatic driving control system for a vehicle traveling on a road on which a marker that emits a steady magnetic field or a quasi-steady magnetic field is installed, A magnetic sensor array mounted on the vehicle and configured to detect magnetism; an information processing circuit that generates an image showing a magnetic field in a region closer to the marker than the magnetic sensor array according to the magnetic sensing result and fundamental equations of a stationary magnetic field and a quasi-stationary magnetic field, and controls the running of the vehicle according to the image; The marker is installed on the road; and an induction circuit mounted on the vehicle and configured to induce a first magnetic field component; The marker is an electrically conductive material, and generates a stationary magnetic field or a quasi-stationary magnetic field by inducing a second magnetic field component by the first magnetic field component. Autonomous driving control system.

2. The information processing circuit includes: Obtaining a speed of the vehicle; converting the temporal change of the sensing result into a spatial change according to the velocity; generating the image according to the sensing result in which the temporal change is converted into the spatial change and according to the fundamental equation; The automatic driving control system according to claim 1 .

3. The magnetic sensor array is composed of one or more two-dimensional magnetic sensor arrays along the longitudinal and lateral directions of the vehicle. The automatic driving control system according to claim 1 or 2.

4. The magnetic sensor array is composed of one or more one-dimensional magnetic sensor arrays along the left-right direction of the vehicle. The automatic driving control system according to claim 1 or 2.

5. The magnetic sensor array senses the magnetic field in one layer along the longitudinal direction and the lateral direction of the vehicle. The automatic driving control system according to claim 1 or 2.

6. The magnetic sensor array senses the magnetic field in two layers along the longitudinal and lateral directions of the vehicle. The automatic driving control system according to claim 1 or 2.

7. The information processing circuit calculates the sensing result and the fundamental equation as an arithmetic formula. [0010] generating said image according to In the above formula, H ｉ (x, y, z) indicates the i component of the magnetic field at the coordinate position (x, y, z), i indicates x, y, or z, z indicates a coordinate value in the z direction from the top to the bottom of the vehicle, x indicates a coordinate value in the x direction perpendicular to the z direction, y indicates a coordinate value in the y direction perpendicular to the z direction and the x direction, and f(k ｘ , k ｙ ) represents the sensing result at (x, y, 0) which is the measurement plane. ｉ represents the two-dimensional Fourier transform image of (x, y, 0), and k ｘ indicates the wave number with respect to x, and k ｙ indicates the wave number with respect to y The automatic driving control system according to claim 1 or 2.

8. The information processing circuit calculates the sensing result and the fundamental equation as an arithmetic formula. [0025] generating said image according to In the above formula, H ｉ (x, y, z) indicates the i component of the magnetic field at the coordinate position (x, y, z), i indicates x, y, or z, z indicates a coordinate value in the z direction from the top to the bottom of the vehicle, x indicates a coordinate value in the x direction perpendicular to the z direction, y indicates a coordinate value in the y direction perpendicular to the z direction and the x direction, and f(k ｘ , k ｙ ) represents the sensing result at (x, y, 0) which is the measurement plane. ｉ (x, y, 0) and g(k ｘ , k ｙ ) denotes the gradient in the z direction of the sensing result on the measurement plane (x, y, 0). ｉ (x, y, z) | ｚ＝０ , and k ｘ indicates the wave number with respect to x, and k ｙ indicates the wave number with respect to y The automatic driving control system according to claim 1 or 2.

9. The autonomous driving control system further includes at least one of a camera, a LiDAR, a millimeter wave radar, an ultrasonic sonar, and a GPS receiver mounted on the vehicle, The information processing circuit further controls the running of the vehicle according to at least one of the camera, the LiDAR, the millimeter wave radar, the ultrasonic sonar, and the GPS receiver. The automatic driving control system according to claim 1 or 2.

10. (delete)

11. the automated driving control system includes a plurality of markers each installed on the road as the marker; The plurality of markers emit a steady magnetic field or a quasi-steady magnetic field in a plurality of magnetic patterns for controlling the running of the vehicle. The automatic driving control system according to claim 1 or 2.

12. Each of the plurality of magnetic patterns is a concentric magnetic pattern. The automatic driving control system according to claim 11.

13. Each of the plurality of magnetic patterns is a barcode-like magnetic pattern. The automatic driving control system according to claim 11.

14. Each of the plurality of magnetic patterns is a two-dimensional code-shaped magnetic pattern. The automatic driving control system according to claim 11.

15. the marker represents a code sequence for controlling the running of the vehicle by an arrangement of a plurality of magnetic poles; the code string includes a code for error detection, The information processing circuit includes: Reading the code sequence according to the image; determining whether the read code sequence includes an error according to the code included in the read code sequence; If it is determined that the read code sequence does not include an error, the vehicle's running is controlled in accordance with the read code sequence. The automatic driving control system according to claim 1 or 2.

16. The marker has a wire-like shape. The automatic driving control system according to claim 1 or 2.

17. (delete)

18. (delete)

19. (delete)

20. An automatic driving control method for a vehicle traveling on a road on which a marker that emits a steady magnetic field or a quasi-steady magnetic field is installed, comprising: Detecting magnetism with a magnetic sensor array mounted on the vehicle; generating an image showing a magnetic field in a region closer to the marker than the magnetic sensor array according to the magnetic sensing result and a fundamental equation of a stationary magnetic field and a quasi-stationary magnetic field, and controlling the traveling of the vehicle according to the image; Inducing a first magnetic field component by an induction circuit mounted on the vehicle; The marker is an electrically conductive material, and generates a stationary magnetic field or a quasi-stationary magnetic field by inducing a second magnetic field component by the first magnetic field component. Autonomous driving control method.

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