Construction member and construction method

Abstract

A construction member (1) for laying magnetic markers (10) at intervals along a vehicle travel path includes a rod-like holding member (11) for holding two or more magnetic markers (10) at intervals in the lengthwise direction, and the construction member (1) is for construction in which a ground surface (111) forming a lower surface on the occasion of construction is provided and a plurality of magnetic markers (10) are held so that the magnetization directions thereof are aligned along the normal direction of the ground surface (111). The construction member (1) is useful for efficiently laying the magnetic markers (10).

Description

Construction materials and construction methods

[0001] The present invention relates to an installation member and an installation method for laying magnetic markers on vehicle tracks.

[0002] Conventionally, a system has been proposed that realizes automatic steering of a vehicle by using magnetic markers placed along the vehicle's route (see, for example, Patent Document 1). Utilizing such a system can reduce the burden on the driver by assisting the vehicle's driving, or reduce the need for the driver to drive the vehicle by realizing automatic driving. Such a system is particularly useful and promising for BRT (Bus Rapid Transit), which automatically drives vehicles such as buses.

[0003] Patent No. 7260856

[0004] However, the conventional magnetic markers have the following problems. For example, to achieve automatic vehicle steering, magnetic markers need to be installed at relatively short intervals, and if the installation work for each magnetic marker is not efficient enough, there is a risk that an increase in construction costs will become unavoidable. In particular, for BRT systems, where vehicles such as buses automatically travel on dedicated lanes, the width of the lanes is set to be extremely narrow compared to expressways and other systems on which ordinary vehicles travel. Therefore, the magnetic markers need to be installed at closer intervals to further reduce the amount of lateral deviation of the vehicles, which is likely to further increase construction costs.

[0005] The present invention has been made in consideration of the above-mentioned problems of the conventional art, and provides an installation member and an installation method for efficiently laying magnetic markers.

[0006] One aspect of the present invention is a construction element for laying magnetic markers at intervals along a vehicle path, which includes a rod-shaped holding element having a plurality of spaces for arranging the magnetic markers at intervals along the longitudinal direction, and the construction element is held by the holding element with a number of magnetic markers equal to the number of spaces provided in the holding element, or a number of magnetic markers less than the number of spaces.

[0007] One aspect of the present invention is a construction method for laying magnetic markers at intervals along a vehicle path, which utilizes a rod-shaped construction member that holds two or more magnetic markers at intervals in the longitudinal direction and has installation holes drilled in at least two locations in the longitudinal direction for passing axial anchor members for fixing to the road surface, and includes the steps of: joining the construction member to the road surface using an adhesive material; and fixing the construction member joined to the road surface with the adhesive material to the road surface using the anchor members that are positioned to pass through the installation holes, and after performing the joining step and before performing the fixing step, the construction method also includes the steps of identifying the amount of positional deviation on the road surface of the construction member joined to the road surface with the adhesive material and adjusting the amount of positional deviation.

[0008] By installing the installation member of one aspect of the present invention, multiple magnetic markers can be installed at once. This installation member has the excellent property of being able to efficiently install multiple magnetic markers in a single installation operation.

[0009] The magnetic markers are then fixed to the road surface with anchor members after adjusting the positional deviation of the adhesive material attached to the road surface.

[0010] The amount of misalignment of the construction members that are simply joined to the road surface with an adhesive material can be adjusted while they remain joined to the road surface. Furthermore, the construction members that are simply joined to the road surface with an adhesive material can be removed from the road surface and their position can be changed. If the amount of misalignment of the construction members that are joined with an adhesive material is identified and adjusted before they are fixed to the road surface with anchor members, positional installation defects of the construction members can be prevented in advance, and the installation efficiency of the magnetic markers can be improved.

[0011] 1 is an explanatory diagram of a track on which magnetic markers are installed in Example 1. A perspective view of a construction member in Example 1. A cross-sectional view along the longitudinal direction of a construction member in Example 1. A perspective view of a magnetic marker in Example 1. A side view of a track on which construction members are arranged in Example 1. A top view of a track on which construction members are arranged in Example 1. A perspective view of another construction member 1 in Example 1. A cross-sectional view along the longitudinal direction of another construction member 2 in Example 1. A perspective view of another construction member 3 in Example 1. A cross-sectional view along the longitudinal direction of another construction member 4 in Example 1. A perspective view of another magnetic marker in Example 1. A perspective view of another construction member 5 in Example 1. An explanatory diagram of a system including a vehicle equipped with LiDAR and a forward camera in Example 2. A cross-sectional view along the longitudinal direction of construction member 1 in Example 2. A cross-sectional view along the longitudinal direction of construction member 2 in Example 2.

[0012] The following examples are provided to explain the present invention in detail. (Example 1) This example relates to an installation member 1 and an installation method that are useful for efficiently laying magnetic markers 10 on a track 50 for a vehicle 5. The details will be explained with reference to Figs. 1 to 12.

[0013] 1, the construction member 1 of this example is a construction member that holds five magnetic markers 10. By placing this construction member 1 on the road surface 50S, the five magnetic markers 10 can be laid collectively (simultaneously) on the road surface 50S. The construction member 1 is useful for improving the efficiency of the work of laying magnetic markers 10 along the path 50 of the vehicle 5.

[0014] The magnetic markers 10 laid along the track 50 are used, for example, to realize automatic travel of vehicles 5 such as buses on BRT. This example is a configuration example that assumes application to a BRT track 50 with a narrow track 50. In this example, the magnetic markers 10 are laid at short intervals of 400 mm along the track 50 to sufficiently suppress lateral displacement of the vehicles 5 due to lateral wind gusts.

[0015] A vehicle 5 that uses magnetic markers 10 has a sensor array 51 attached to its bottom surface for detecting the magnetic markers 10. The sensor array 51 is a rod-shaped magnetic sensor unit with multiple magnetic sensors (not shown) arranged longitudinally. This sensor array 51 is attached to the vehicle 5 along the vehicle width direction, as shown in FIG. 1 . The sensor array 51 detects the magnetic markers 10 while the vehicle 5 is traveling, and measures the amount of lateral deviation of the vehicle 5 relative to the magnetic markers 10. By steering the steering wheels of the vehicle 5 so that the amount of lateral deviation relative to the magnetic markers 10 approaches a predetermined amount, such as zero, it becomes possible to drive the vehicle 5 along the road 50.

[0016] The construction member 1 (Fig. 2) is a construction member in which a plurality of magnetic markers 10 are held by a rod-shaped holding member 11 with a length of 2000 mm. The cross section of the holding member 11 is rectangular, with the cross-sectional dimensions being 150 mm wide and 20 mm thick. The holding member 11 is formed, for example, from a composite material of plastic and wood materials.

[0017] The holding member 11 has five accommodation holes (spaces) 15 drilled in the longitudinal direction, for example, at intervals of 400 mm. The accommodation holes 15 are through-holes in the thickness direction (see Figure 3). The accommodation holes 15 on both ends are drilled at positions 200 mm from the ends. In addition, installation holes 13 are drilled at two positions approximately 400 mm from each end of the construction member 1.

[0018] Each storage hole 15 is a hole for storing one individual, independent pellet-shaped magnetic marker 10. The cross-sectional shape of the storage hole 15 is not a uniform circle, as shown in Figure 3, which shows the cross-sectional structure along the longitudinal direction of the construction member 1, but has a large diameter portion 15D on one opening side. The opening side on which the large diameter portion 15D is formed forms the underside during construction, and is the side of the ground contact surface 111 that faces the road surface 50S. The storage hole 15 with the large diameter portion 15D has a stepped, flared structure toward the ground contact surface 111 side. The large diameter portion 15D serves as the entrance when inserting the magnetic marker 10 into the storage hole 15.

[0019] The installation hole 13 is a through-hole with a uniform cross-sectional shape, as shown in Fig. 3. The installation hole 13 is used to pass an anchor bolt 100 (see Fig. 2, an example of a shaft-shaped anchor member) through the installation hole 13 to fix the construction member 1 to the road surface 50S. Unlike the receiving hole 15, the cross-sectional shape of the installation hole 13 is a uniform circle.

[0020] The magnetic marker 10 (FIG. 4) held by the construction member 1 is a ferrite plastic magnet with a roughly cylindrical shape. One end face of the roughly cylindrical magnetic marker 10 forms a north pole, and the other end face forms a south pole. The magnetization direction of the magnetic marker 10 is along the axial direction of the roughly cylindrical shape. As shown in FIG. 3, when the magnetic marker 10 is attached to the holding member 11, the magnetization direction of the magnetic marker 10 is along the thickness direction of the holding member 11, which corresponds to the normal direction of the ground surface 111. In this configuration, magnetic markers 10 are placed in all of the storage holes 15 of the holding member 11. In other words, in this example, the holding member 11 holds a number of magnetic markers 10 equal to five, which is the upper limit number of magnetic markers 10 (the number of storage holes 15) that can be held by the holding member 11.

[0021] A large-diameter flange portion 10F is provided at one end of the magnetic marker 10, and the other end has a stepped, tapered shape. The magnetic marker 10 can be inserted into the storage hole 15 with the other end at the front. The flange portion 10F of the magnetic marker 10 is configured to be received in the large-diameter portion 15D of the storage hole 15 (see Figure 3). While this flange portion 10F can be received in the large-diameter portion 15D, it is too small to be inserted through the storage hole 15.

[0022] The flange portion 10F functions to prevent the magnetic marker 10 from coming out. The combination of the magnetic marker 10 and the storage hole 15 allows the magnetic marker 10 to be inserted into the storage hole 15 from the side of the ground surface 111 (holding member 11), while making it impossible to remove the magnetic marker 10 from the side opposite the ground surface 111.

[0023] Instead of the stepped accommodating hole 15, a diverging accommodating hole may be used, with the inner diameter gradually increasing toward the ground surface 111. The corresponding magnetic marker may have a tapered shape with the cross-sectional diameter gradually decreasing toward the insertion direction, or may have a stepped tapered shape as shown in this example. The magnetic marker may also have a diverging shape with the outer diameter gradually increasing toward one end. The corresponding accommodating hole may have a diverging structure with the inner diameter gradually increasing toward the ground surface 111, or may have a stepped diverging structure.

[0024] In this example, the end face of the magnetic marker 10 on the flange 10F side is an S pole, and the opposite end face is an N pole. Therefore, when a vehicle 5 passes the magnetic marker 10, it is detected by the vehicle 5 as a N pole magnetic marker 10. It is also possible to prepare two types of magnetic markers: one with an S pole on the flange 10F side and the other with an N pole on the flange 10F side. In this case, for example, it is possible to realize a configuration in which the magnetic polarity of the magnetic markers 10 at a specific location on the track 50 is different from the magnetic polarity of the other magnetic markers 10. Furthermore, for example, it is also possible to transmit information to the vehicle 5 based on the combination of magnetic polarities of the magnetic markers 10 detected sequentially by the vehicle 5 traveling on the track 50 (for example, in the case of a combination of three magnetic markers 10, combinations such as NNN, NSN, SSS, and NNS). The information to be transmitted may include various types of information, such as information indicating a location, information about road structures, and information about traffic rules.

[0025] In the construction member 1, an adhesive layer 12 made of an adhesive material such as butyl rubber is formed on the contact surface 111 side of the holding member 11 when the magnetic markers 10 are inserted into each storage hole 15 (see Figure 3). In the construction member 1 in its finished state before construction, a release paper (not shown) is attached to the adhesive layer 12. During construction, the construction member 1 can be joined to the road surface 50S by peeling off the release paper and pressing the adhesive layer 12 against the road surface 50S. It is possible to temporarily place the construction member 1 on the road surface 50S before peeling off the release paper to check its position. It is also possible to provide the adhesive layer 12 on the contact surface 111 except for the end faces of the magnetic markers 10. In this case, the magnetic markers 10 can be inserted into each storage hole 15 even after the adhesive layer 12 is formed on the holding member 11.

[0026] The construction member 1 in this example is adhesively bonded to the road surface 50S with an adhesive material, and its position on the road surface 50S is fixed by anchor bolts 100 (see FIG. 2). When constructing the construction member 1, it is advisable to first carry out a process of adhesively bonding the construction member 1 to the road surface 50S with the adhesive material, and then carry out a process of identifying and adjusting the amount of misalignment of the construction member 1 on the road surface.

[0027] Here, the adhesively bonded construction member 1 can be displaced or peeled off from the road surface 50S by the application of a sustained external force rather than an impact external force. On the other hand, the adhesively bonded construction member 1 is less likely to immediately fall off the road surface 50S or become displaced even if a temporary external force is applied. If the construction member 1 is adhesively bonded to the road surface 50S, it is also possible to actually run the vehicle 5 and check the system operation. System operation allows the amount of positional deviation of the construction member 1 to be determined and the amount of positional deviation to be adjusted with high precision. After positioning the construction member 1 in this adhesively bonded state, a process of driving the anchor bolt 100 inserted through the installation hole 13 into the road surface 50S to fix the position of the construction member 1 is preferably performed. Note that the amount of positional deviation can also be determined by position surveying or the like, regardless of system operation.

[0028] As described above, adhesive bonding can prevent positional fluctuations caused by temporary external forces, but it is prone to positional changes over time in the construction member 1. On the other hand, the anchor bolt 100 (see FIG. 2) can reliably prevent positional fluctuations in the construction member 1 over a long period of time, but the construction member 1 may become loosened from the road surface 50S due to the action of external forces. By combining adhesive bonding and fixation with the anchor bolt 100, it is possible to suppress positional fluctuations in the construction member 1 caused by temporary external forces with the adhesive bonding, while preventing positional changes over time with the anchor bolt 100.

[0029] As shown in Figures 5 and 6, the construction members 1 are arranged in series along the track 50 with few gaps between them. On a straight track 50, each construction member 1 is laid in a straight line along the center line of the track 50. On a curved track 50, each construction member 1 is laid in a tangential direction to the center line of the track 50. An appropriate gap is set between adjacent construction members 1 to accommodate expansion and contraction of the holding members 11 due to environmental changes such as temperature and humidity. During construction, it is a good idea to use a jig such as a spacer to ensure an appropriate gap.

[0030] As described above, by using the construction member 1 of this example, it is possible to lay five magnetic markers 10 all at once by performing a single operation of applying the construction member 1 to the road surface 50S. When using the construction member 1, the number of positioning operations on the road surface 50S can be reduced to one-fifth compared to the operation of laying the magnetic markers 10 one by one on the road surface 50S. By using the construction member 1, it is possible to lay the magnetic markers 10 efficiently, thereby reducing construction costs.

[0031] In the construction member 1, five magnetic markers 10 are housed in housing holes 15 that have been drilled with high positional precision in a factory or the like. Therefore, in the construction member 1, high precision can be ensured in the spacing between the magnetic markers 10, the linearity of the lines connecting the five magnetic markers 10, and the like. These precisions are significantly higher than when the magnetic markers 10 are placed one by one by on-site work.

[0032] In this example, the magnetic marker 10 is accommodated in the accommodation hole 15 of the construction member 1 from the ground surface 111 side. Alternatively, the magnetic marker may be inserted into the accommodation hole by driving it in from the surface 113 side. Unlike the magnetic marker 10 illustrated, the magnetic marker to be inserted into the accommodation hole may be columnar and have no flange portion 10F. The accommodation hole may be columnar and have a uniform cross-sectional shape. The magnetic marker accommodated in the accommodation hole 15 may be fixed by interference fit (a form of fitting), adhesive fixation with an adhesive material, adhesive fixation with an adhesive material laminated on the ground surface 111 side, or a combination of these methods to fix the magnetic marker inside the accommodation hole 15. The accommodation hole may have a bottom. Instead of insertion, a molten material with magnetic properties may be injected into the accommodation hole to form a magnet inside, which may then be magnetized. Examples of materials with magnetic properties include resin materials mixed with magnetic powder.

[0033] The construction member 1 is a rod-shaped member that holds multiple markers 10, and is a rail-like member that is laid along the track 50 for the vehicle 5. The construction member 1 may be appropriately called a marker rail, for example. In this example, a rail-shaped construction member 1 that is 2000 mm long and holds five magnetic markers 10 is shown, but the length of the construction member 1 and the number of magnetic markers 10 can be changed as appropriate.

[0034] As shown in FIG. 7, the holding member 11 may be provided with closely spaced storage holes 15. This figure shows an example in which 15 storage holes 15 are provided. In this case, magnetic markers 10 may be placed in all 15 storage holes 15, or magnetic markers 10 may be selectively placed in the 15 storage holes 15. For example, as shown in FIG. 7, magnetic markers 10 may be placed in every other storage hole 15 in the longitudinal direction, every third storage hole 15 in the longitudinal direction, or every third storage hole 15 in the longitudinal direction. In FIG. 7, storage holes 15 in which no magnetic markers 10 are placed are indicated by vertical hatching. In the case of the construction member 1 shown in the figure, eight magnetic markers 10, which is fewer than the number of storage holes 15 (spaces) provided in the holding member 11, are held by the holding member 11. By selectively placing magnetic markers 10 in the 15 storage holes 15, multiple types of construction members 1 with different placement pitches of the magnetic markers 10 can be produced using one type of holding member 11.

[0035] In addition, in a construction member 1 including a retaining member 11 (see Figure 7) in which storage holes 15 are arranged at small, equal intervals, the spacing between the magnetic markers 10 can be made uneven by selecting the storage holes 15 in which the magnetic markers 10 are placed.

[0036] In this example, a composite material of plastic and wood-based materials is used as the material for forming the rod-shaped holding members 11 that make up the construction member 1. Alternatively, the holding members 11 may be made of an elastic or plastic material. A construction member 1 that includes holding members 11 made of an elastic or plastic material can be deformed into a curved shape. In this case, construction members with longer overall lengths, such as 10 m or 20 m, can be used, as this makes it easier to lay them on curved roads.

[0037] In this example, the storage hole 15 for the magnetic marker 10 is exemplified as a hole that penetrates the construction member 1 in the thickness direction. The storage hole 15 may have a bottom when viewed from the ground surface 111 side, as shown in Figure 8. In this case, the end face of the magnetic marker 10 is not exposed on the surface side of the construction member 1, and deterioration of the magnetic marker 10 over time can be suppressed.

[0038] In this example, a cylindrical ferrite plastic magnet is used as the magnetic marker 10 to be incorporated into the construction member 1. Alternatively, individualized sheet-shaped ferrite rubber magnets may be used as the magnetic markers 10. A sheet-shaped magnetic marker 10 can be attached to the surface 113 of the construction member 1, as shown in FIG. 9. Alternatively, the sheet-shaped magnetic marker 10 can be placed on the back side of the construction member 1, on the ground surface 111 side. For example, the sheet-shaped magnetic marker 10 may be placed between the holding member 11 and the adhesive layer 12. A recess may be provided in the holding member 11 as a space to accommodate the sheet-shaped magnetic marker 10, or the position where the sheet-shaped magnetic marker 10 can be placed may be treated as the space.

[0039] The holding member 11 of this example may also be formed by bonding two 10 mm thick intermediate members 11D together, as shown in Figure 10. In this case, individual sheet-like magnetic markers 10 can be placed on the bonding surfaces of the two intermediate members 11D. In this case, a construction member 1 can be realized in which the magnetic markers 10 are completely placed inside.

[0040] At least one of the magnetic markers 10 attached to the construction member 1 may hold a sheet-like wireless tag 10T, as shown in FIG. 11 . The wireless tag 10T can be powered wirelessly from the vehicle 5 and can wirelessly transmit location information and the like to the vehicle 5. In this example, a BRT is assumed in which the vehicle 5 does not travel obliquely along the road 50, and a 20 mm-thick construction member 1 is attached to the road surface 50S. If the wireless tag 10T is configured to be located on the surface 113 of the construction member 1 (the surface opposite the ground contact surface 111), the wireless tag 10T can be positioned 20 mm higher than the road surface 50S. In this case, the wireless tag 10T is less likely to be covered with moisture during rainy weather, preventing deterioration of communication performance due to moisture. Alternatively, as shown in FIG. 12 , the wireless tag 10T may be attached to the surface of the holding member 11, midway between any two adjacent magnetic markers 10.

[0041] A solar cell panel (not shown) may be provided on the surface of the construction member 1. Furthermore, although not shown, the construction member 1 may be provided with a circuit that receives wireless power from the vehicle 5, a circuit that generates power from vibrations caused by the vehicle 5 traveling, a circuit that generates power from electromagnetic induction according to the traveling of the vehicle 5, a power receiving circuit that corresponds to the wireless power feeding circuit on the vehicle 5, etc. Furthermore, if the construction member 1 has a built-in battery (not shown), road-to-vehicle communication with the vehicle 5 can be realized, and communication with a server device (not shown) and the like can also be enabled.

[0042] In this example, the sensor array 51 is disposed at the front of the vehicle 5. The sensor array 51 may also be disposed at two or more positions in the longitudinal direction, such as at the front and rear of the vehicle 5. The longitudinal separation distance between the sensor arrays 51 may be, for example, a multiple of the arrangement pitch of the magnetic markers 10. In this case, the front and rear sensor arrays 51 can simultaneously detect magnetic markers 10 at different longitudinal positions. The difference between the two lateral deviation amounts for two magnetic markers 10 measured by two sensor arrays 51 at different longitudinal positions can be an index representing the deviation of the orientation of the vehicle 5 relative to the longitudinal direction of the construction member 1. Based on this difference, it is also possible to calculate the angular deviation of the orientation of the vehicle relative to the longitudinal direction of the construction member 1.

[0043] In this example, the construction member 1 is placed on the surface of the road surface 50S. Alternatively, the magnetic marker 10 may be laid by placing the construction member 1 in a groove formed in the road surface 50S or by burying the construction member 1 in the roadway. In this example, the construction member 1 is exemplified as having the magnetization direction of the magnetic marker 10 aligned along the normal direction of the ground surface 111, but the magnetization direction of the magnetic marker 10 can be changed as desired.

[0044] (Example 2) This example is based on the configuration of Example 1, but is an example in which the configuration of the construction member 1 is changed so that it can be detected by various sensors provided on the vehicle 5. This will be described with reference to Figs. 13 to 15.

[0045] 13, the vehicle 5 of this example is equipped with a sensor array 51, a direct-below LiDAR 521 for detecting unevenness directly below, a forward LiDAR 523 for detecting objects in front, and a forward camera 55 (an example of an image sensor) for recognizing the forward environment. The surface of the construction member 1 of this example (the surface opposite the ground side) is configured to exhibit properties that can be detected by the forward LiDAR 523, the direct-below LiDAR 521, and the forward camera 55. Here, LiDAR is a sensor that detects objects using laser light.

[0046] A reflective layer 17 made of a reflective material (an example of a material that reflects electromagnetic waves) is laminated on the surface of the construction member 1 illustrated in Fig. 14. Examples of the reflective material include transparent paint containing aluminum powder or reflective beads, and highly reflective paint. The reflective layer 17 efficiently reflects the laser light from the direct-beam LiDAR 521 and forward LiDAR 523, thereby increasing the detectability of the construction member 1.

[0047] When the reflective layer 17 is provided, it is possible to improve the reflectance of visible light such as the light from the headlights of the vehicle 5, the light from street lamps, and sunlight. In this case, the construction member 1 appears brighter than the surrounding road surface in the image captured by the front camera 55, making it easier to detect the construction member 1 visually. In order to further improve the detection rate of the construction member 1 by the front camera 55, it is also possible to devise the color tone or pattern of the surface of the construction member 1 or the reflective layer 17.

[0048] The surface of the construction member 1 illustrated in Fig. 15 is formed to be jagged, and multiple reflective surfaces 170 are formed that are perpendicular to the oblique incident direction of the laser light from the front LiDAR 523. These reflective surfaces 170 efficiently reflect the laser light from the front LiDAR 523, improving the detection rate of the construction member 1. Like laser light, the reflective surfaces 170 also reflect visible light. Providing the reflective surfaces 170 can improve the detection rate of the construction member 1 by the front camera 55.

[0049] By detecting the construction member 1 in front using the front LiDAR 523 or the front camera 55, the shape of the road ahead can be grasped. Understanding the road shape is useful for steering control of the vehicle 5. As explained in Example 1, the amount of lateral deviation of the vehicle 5 can be measured by using the magnetic markers 10. By combining the detection of the construction member 1 in front with the detection of the magnetic markers 10, steering control becomes possible, such as steering according to the shape of the road 50 ahead and steering to correct the lateral position (position in the vehicle width direction) of the vehicle 5 within the road 50 using the magnetic markers 10.

[0050] Furthermore, the direct-beam LiDAR 521, which detects unevenness in the road surface 50S, is suitable as a sensor for detecting a 20 mm thick construction member 1 placed on the road surface 50S. By detecting the surface of the construction member 1 that is 20 mm higher than the road surface 50S, it is possible to measure the relative position (lateral position) of the construction member 1 in the vehicle width direction relative to the vehicle 5. The lateral position of the construction member 1 measured by the direct-beam LiDAR 521 can be used to verify the amount of lateral deviation with respect to the magnetic marker 10 measured by the sensor array 51, which is useful for improving the robustness of the system.

[0051] In addition, in Example 1, it is explained that the sensor arrays 51 may be arranged at two or more positions in the longitudinal direction of the vehicle 5. A direct-below LiDAR 521 may be attached to each sensor array 51. The direct-below LiDARs 521 located at different longitudinal positions can each measure the lateral position of the construction member 1. The difference between the lateral positions of the construction member 1 measured by the two direct-below LiDARs 521 located at different longitudinal positions can be an index representing the deviation of the orientation of the vehicle 5 relative to the longitudinal direction of the construction member 1.

[0052] In this example, LiDAR that uses laser light (an example of electromagnetic waves) is used as a radar sensor (active sensor) for detecting the construction member 1. Instead of or in addition to LiDAR, it is also possible to use a radio wave radar such as a millimeter wave radar that uses radio waves (an example of electromagnetic waves) to detect an object. Furthermore, it is also possible to appropriately combine LiDAR and radio wave radar.

[0053] In this example, a vehicle 5 is illustrated that is equipped with a forward camera 55 in addition to a direct-navigation LiDAR 521 and a forward LiDAR 523. The forward camera 55 may be omitted from the vehicle. In this case, the construction member 1 does not need to have a surface texture that can be detected by an image sensor. The surface of the construction member 1 may be configured to have a texture that can be detected by a radar sensor. On the other hand, if the construction member 1 can be detected by an on-board camera, surface texture that can be detected by LiDAR is not essential. In this case, the vehicle 5 may be equipped with a forward camera 55, and the direct-navigation LiDAR 521 and forward LiDAR 523 may be omitted. Furthermore, the direct-navigation LiDAR 521 is not an essential component and may be omitted from the vehicle 5.

[0054] The other configurations and effects are the same as those of the first embodiment.

[0055] Although specific examples of the present invention have been described in detail as examples, these examples merely disclose examples of the technology encompassed by the claims. Needless to say, the scope of the claims should not be interpreted as being limited by the configurations, numerical values, etc. of the specific examples. The claims encompass technologies that are obtained by variously modifying, changing, or appropriately combining the specific examples using publicly known technology and the knowledge of those skilled in the art.

[0056] 1 Construction member 10 Magnetic marker 10F Flange portion 10T Wireless tag 100 Anchor bolt (anchor member) 11 Holding member 111 Ground surface 113 Surface 12 Adhesive layer 13 Installation hole 15 Storage hole (space) 15D Large diameter portion 17 Reflective layer 5 Vehicle (bus) 50 Running path 50S Road surface 51 Sensor array 521 Direct-down LiDAR 523 Forward LiDAR 55 Forward camera

Claims

1. A construction component for laying magnetic markers at intervals along a vehicle path, comprising a rod-shaped retaining member having a plurality of spaces for arranging the magnetic markers at intervals in the longitudinal direction, and a number of magnetic markers equal to the number of spaces provided in the retaining member, or a number of magnetic markers less than the number of spaces, being held by the retaining member.

2. A construction member as described in claim 1, in which each magnetic marker is held so that the magnetization direction is aligned along the normal direction of the ground surface forming the lower surface during construction.

3. In claim 1, the retaining member has installation holes drilled in at least two places in the longitudinal direction for passing shaft-shaped anchor members for fixing to the road surface, and an adhesive layer made of an adhesive material is laminated on the contact surface that forms the underside during construction, and the construction member is adhesively bonded to the road surface by the adhesive material of the adhesive layer and is fixed to the road surface by the anchor members that pass through the installation holes.

4. An installation member according to claim 1, in which an adhesive layer made of an adhesive material is laminated on the contact surface that forms the underside during installation, and each magnetic marker is an individualized sheet-like magnetic marker and is disposed between the adhesive layer and the holding member.

5. A construction member in accordance with claim 1, in which each magnetic marker is a columnar magnetic marker and is placed in a storage hole drilled in the retaining member, and the combination of the storage hole and each magnetic marker is configured such that, during construction, each magnetic marker can be inserted into the storage hole from the ground surface side that forms the underside, but each magnetic marker cannot be removed from the side opposite the ground surface.

6. An installation member as set forth in claim 5, wherein the accommodating hole has a structure that widens toward the ground surface, and each of the magnetic markers has a shape that narrows toward the direction of insertion into the accommodating hole.

7. A construction member as claimed in claim 1, the surface opposite the contact surface that forms the underside during construction exhibits properties that can be detected by at least one of an image sensor and a radar sensor mounted on a vehicle.

8. A construction member according to claim 7, wherein a layer made of a material that reflects electromagnetic waves is provided on the surface opposite the ground surface.

9. A construction member as claimed in claim 1, wherein each magnetic marker is a columnar magnetic marker, the space is a storage hole capable of storing the columnar magnetic marker, and the spacing between two adjacent magnetic markers can be selectively set depending on in which of the multiple storage holes each magnetic marker is placed.

10. A construction method for laying magnetic markers at intervals along a vehicle path, comprising: a rod-shaped construction member that holds two or more magnetic markers at intervals in the longitudinal direction and has installation holes at at least two locations in the longitudinal direction for passing shaft-shaped anchor members for fixing the member to the road surface; a step of joining the construction member to the road surface using an adhesive material; and a step of fixing the construction member joined to the road surface with the adhesive material to the road surface using the anchor members that are disposed to pass through the installation holes; and a step of determining the amount of positional deviation on the road surface of the construction member joined to the road surface with the adhesive material after performing the joining step and before performing the fixing step, and adjusting the amount of positional deviation.

11. A construction method as described in claim 10, wherein the construction member includes a rod-shaped holding member having a plurality of spaces for arranging magnetic markers at intervals in the longitudinal direction, and the holding member holds a number of magnetic markers equal to the number of spaces provided in the holding member, or a number of magnetic markers less than the number of spaces.

Images