Marker system and control method

Abstract

To provide a marker system that can relatively easily ensure a detection reliability of a magnetic marker.SOLUTION: In a marker system 1 in which magnetic markers 10 are arranged at intervals along a route 100 on which a vehicle 2 travels, in a combination of two adjacent magnetic markers 10 which are installed on a main road 110 and a side road 120 in a lateral direction, when a separated distance in the lateral direction is equal to or shorter than 0.3 m, a combination of magnetic polarities is a combination of different magnetic polarities, whereas when a separated distance in the lateral direction exceeds 0.3 m, a combination of magnetic polarities is the same combination of magnetic polarities.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a marker system in which magnetic markers are arranged on a road so that they can be detected while the vehicle is traveling, and a vehicle control method. [Background technology]

[0002] Marker systems have been known in the past in which magnetic markers are placed along a roadway so that the vehicle can detect them while it is traveling (see, for example, Patent Document 1). This marker system is intended for vehicles equipped with a magnetic sensor unit with a detection area that is long in the vehicle width direction, for example. The vehicle detects the magnetic markers while traveling and measures the lateral deviation from the detected magnetic markers. In the marker system, for example, the steering wheels are controlled so that the lateral deviation from the magnetic marker approaches zero, thereby enabling the vehicle to travel automatically along the roadway. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 2017-199247 Summary of the Invention [Problem to be solved by the invention]

[0004] However, the conventional marker system has the following problem: For example, at a branch road or merging road that is diagonal to the main road, a magnetic marker placed on the main road and a magnetic marker placed on the branch road or merging road may be side-by-side, which may increase the processing load for reliably detecting the magnetic markers and the processing load for vehicle control due to magnetic interference between adjacent magnetic markers.

[0005] The present invention has been made in consideration of the above-mentioned conventional problems, and aims to provide a marker system that can relatively easily ensure the reliability of detection of magnetic markers, and a control method that realizes highly accurate vehicle control. [Means for solving the problem]

[0006] One aspect of the present invention is a marker system in which magnetic markers are arranged at intervals along a route traveled by a vehicle, the marker system comprising: In a combination of two magnetic markers that are laid on different routes and are adjacent to each other in a direction perpendicular to the route direction, the combination of magnetic polarities differs depending on whether the distance between the two magnetic markers is equal to or less than a predetermined threshold value, If the distance between the two magnetic markers is equal to or less than a predetermined threshold, the magnetic polarity combination is a different magnetic polarity combination; If the distance between the two magnetic markers exceeds a predetermined threshold or is equal to or greater than the predetermined threshold, the magnetic polarity combination is in the same magnetic polarity combination marker system. [Effects of the Invention]

[0007] One of the technical features of the marker system according to the present invention is the combination of magnetic polarities of two magnetic markers installed next to each other on different routes. The two magnetic markers have different combinations of magnetic polarities depending on whether the distance between the two magnetic markers is equal to or less than a predetermined threshold. When the distance between the two magnetic markers is equal to or less than the predetermined threshold, the two magnetic markers have different combinations of magnetic polarities, whereas when the distance between the two magnetic markers is equal to or greater than the predetermined threshold, the two magnetic markers have the same combination of magnetic polarities.

[0008] The closer two adjacent magnetic markers are to each other, the greater the possibility of magnetic interference. If the two magnetic markers have the same magnetic polarity, the magnetic interference caused by the two magnetic markers will broaden the magnetic distribution, making it difficult to detect the peak that would occur directly above the magnetic marker. On the other hand, if the magnetic polarities of the two adjacent magnetic markers along the width of the route are different, it is relatively easy to detect the peak of the magnetic distribution even if magnetic interference occurs, and each magnetic marker can be detected with high reliability. Reliable detection of magnetic markers can improve the stability of vehicle control that uses magnetic markers. [Brief explanation of the drawings]

[0009] [Figure 1] FIG. 1 is an explanatory diagram of a marker system according to a first embodiment. [Figure 2] FIG. 2 is a perspective view of a magnetic marker according to the first embodiment. [Figure 3] FIG. 1 is a configuration diagram of a vehicle in a first embodiment. [Figure 4] 10 is a graph of an approximation curve representing the distribution of magnetic measurement values ​​derived from one magnetic marker in the vehicle width direction in the first embodiment. [Figure 5] FIG. 1 is an explanatory diagram of the manner in which magnetic markers are installed at a branch point in the first embodiment. [Figure 6] FIG. 10 is an explanatory diagram of the manner in which magnetic markers are installed at a merging point in the first embodiment. [Figure 7] 10 is a graph of an approximate curve showing the distribution in the vehicle width direction of magnetic measurement values ​​derived from two magnetic markers of the same magnetic polarity arranged side by side in Example 1. [Figure 8] 2 is a second graph of an approximate curve representing the distribution in the vehicle width direction of magnetic measurement values ​​derived from two magnetic markers of the same magnetic polarity arranged side by side in Example 1. [Figure 9] 10 is a graph of an approximation curve showing the distribution in the vehicle direction of magnetic measurement values ​​derived from two magnetic markers of different magnetic polarities arranged side by side in the first embodiment. [Figure 10] 10 is a diagram illustrating the relationship between the spacing between two horizontally arranged magnetic markers and the combination of magnetic polarities in the first embodiment. FIG. [Figure 11] 3 is a flowchart showing the flow of vehicle travel control in the first embodiment. [Figure 12] FIG. 3 is an explanatory diagram showing the movement of a vehicle passing through a branch point in the first embodiment. [Figure 13] FIG. 3 is an explanatory diagram showing the movement of a vehicle branching off at a branch point in the first embodiment. [Figure 14] FIG. 2 is an explanatory diagram showing the movement of a vehicle traveling on a main lane and passing through a merging point in the first embodiment. [Figure 15] FIG. 3 is an explanatory diagram showing the movement of a vehicle merging onto a main line at a merging point in the first embodiment. [Figure 16] FIG. 10 is an explanatory diagram showing the structure of a track in the second embodiment. [Figure 17] FIG. 10 is a perspective view of a magnetic marker to which an RFID tag is attached in a second embodiment. [Figure 18] FIG. 11 is an explanatory diagram of the manner in which magnetic markers are installed at a branch point in the third embodiment. [Figure 19] FIG. 10 is an explanatory diagram of the manner in which magnetic markers are installed at a merging point in the third embodiment. [Figure 20] FIG. 11 is a flowchart showing the flow of vehicle travel control in the third embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0010] The embodiments of the present invention will be specifically described using the following examples. Example 1 This example relates to a marker system 1 in which magnetic markers 10 are arranged along a route, and a vehicle control method, which will be described with reference to FIGS.

[0011] The marker system 1 (Fig. 1) of this example is, for example, a system of magnetic markers 10 laid on a track 100 for a vehicle 2. The track 100 is, for example, a track that constitutes a BRT (bus rapid transit) system. On the track 100 to which the marker system 1 is applied, a vehicle 2 (bus vehicle) travels automatically while detecting the magnetic markers 10. Note that Fig. 1 does not show all of the magnetic markers 10 arranged along the track 100, but omits some of them.

[0012] The track 100 is, for example, a one-way circular track with a width of 3 m. Magnetic markers 10 are laid on the track 100 at intervals in the direction of travel. In this example, the magnetic markers 10 are spaced apart at 2 m intervals. The marker system 1 is used for a vehicle 2 to travel along the circular track 100. The track 100 has a section where a side road 120 is provided for a main track 110. The track 100, which consists of the main track 110 and the side road 120, is an example of a route on which the vehicle 2 travels. The side road 120 is an example of a route that branches off from the route that consists of the main track 110, and an example of a route that merges with the route that consists of the main track 110.

[0013] On the road 100 illustrated in FIG. 1, there are two types of driving routes for the vehicle 2. The first driving route is a driving route that travels along the main road 110 without entering the side road 120. The second driving route is a driving route that travels along the main road 110 via the side road 120. The vehicle 2 traveling on the first driving route is controlled to pass directly through a branch point 121 onto the side road 120. The vehicle 2 traveling on the second driving route is controlled to branch off from the branch point 121 onto the side road 120, and then merge onto the main road 110 at a merging point 123.

[0014] The magnetic marker 10 (Figure 2) is a cylindrical magnet with a diameter of 30 mm and a height of 20 mm. One end face of the cylindrical magnetic marker 10 forms a north pole and the other end face forms a south pole. All magnetic markers 10 on the main line 110 are buried with their north pole end faces facing upward. The magnetic markers 10 on the main line 110 are detected as north pole magnets on the vehicle 2 side. The magnetic markers 10 on the side road 120 are buried with their north pole end faces facing upward, except for some of the magnetic markers 10 at the branch point 121 and the merging point 123, which will be described in detail later. In the following explanation, the symbol 10N will be used to refer to a magnetic marker with its north pole facing upward, and the symbol 10S will be used to refer to a magnetic marker with its south pole facing upward.

[0015] The vehicle 2 (Fig. 3) in this example is a bus vehicle with a length of 8 m and a width of 2.3 m. The vehicle 2 has operating systems such as a steering wheel, accelerator, and brake. The vehicle 2 is equipped with a plurality of actuators (not shown) that drive these operating systems, and a control unit 20 that controls these actuators. The vehicle 2 can be driven manually by a driver, and can also be driven automatically under the control of the control unit 20.

[0016] The vehicle 2 is configured to be capable of autonomous driving using magnetic markers 10 laid along a road 100. The vehicle 2 is equipped with a magnetic sensor module 3 for detecting the magnetic markers 10. The magnetic sensor module 3 is attached to the front of the vehicle 2. The magnetic sensor module 3 executes a process (marker detection process) for detecting the magnetic markers 10 in accordance with control by a control unit 20.

[0017] The magnetic sensor module 3 is an example of a magnetic detection circuit having a magnetic detection area that is long in the vehicle width direction. Although not shown, the magnetic sensor module 3 is a sensor unit that includes multiple magnetic sensors and a processing circuit that executes arithmetic processing. In the magnetic sensor module 3, multiple magnetic sensors (not shown) are attached at intervals to a rod-shaped frame. The magnetic sensor module 3 is attached to the vehicle 2 so that its longitudinal direction is along the vehicle width direction. The length of the rod-shaped magnetic sensor module 3 is close to the width of the vehicle 2. The magnetic sensor module 3 has a magnetic detection area that is long in the vehicle width direction. The magnetic sensor module 3 can reliably detect the magnetic marker 10 regardless of lateral deviation of the vehicle 2 within the road 100.

[0018] Each magnetic sensor in the magnetic sensor module 3 is built in so that it can measure the magnitude of magnetic fields acting in the vertical direction. When the magnetic sensor module 3 is located directly above the magnetic marker 10, the distribution of magnetic measurement values ​​from the multiple magnetic sensors arranged in the vehicle width direction is, for example, as shown in Figure 4. This figure shows the magnetic measurement values ​​of each magnetic sensor approximated by a curve. The horizontal axis in this figure indicates the vehicle width direction. As shown in this figure, when the magnetic sensor module 3 is located directly above the magnetic marker 10, the distribution of magnetic measurement values ​​from each magnetic sensor becomes a mountain-shaped magnetic distribution with a peak value directly above the magnetic marker 10.

[0019] The processing circuit of the magnetic sensor module 3 applies a marker detection process to the distribution of magnetic measurement values ​​of each magnetic sensor. In the marker detection process, when there is one peak exceeding a threshold, as in the approximate curve of FIG. 4, for example, it is determined that one magnetic marker 10 has been detected.

[0020] In the marker detection process, in addition to determining whether or not the magnetic marker 10 was detected, the magnetic polarity of the detected magnetic marker 10 is determined, and the lateral deviation of the vehicle 2 relative to the detected magnetic marker 10 is measured. Each magnetic sensor of the magnetic sensor module 3 is configured to output a positive magnetic measurement value in response to the magnetism acting from the magnetic marker 10N with an N pole, and to output a negative magnetic measurement value in response to the magnetic marker 10S with an S pole, as in the example of FIG. 4 . In the marker detection process, the magnetic polarity of the magnetic marker 10 is determined depending on whether the peak value when the magnetic marker 10 is detected is positive or negative. In addition, in the marker detection process, the lateral deviation of the vehicle relative to the magnetic marker 10 is identified (measured) by identifying the position of the peak value in the vehicle width direction.

[0021] When the magnetic sensor module 3 executes the marker detection process, it outputs the processing result. The processing result includes information on whether or not the magnetic marker 10 has been detected. Furthermore, when the magnetic marker 10 has been detected, the processing result includes information on the magnetic polarity of the detected magnetic marker 10 and information on the lateral deviation relative to the magnetic marker 10.

[0022] As described above, the magnetic sensor module 3 has a magnetic detection area that is long in the vehicle width direction. When multiple magnetic markers 10 are arranged side by side in the vehicle width direction, multiple magnetic markers 10 may be included in the magnetic detection area of ​​the magnetic sensor module 3. The magnetic sensor module 3 is configured to be able to output the magnetic polarity and lateral deviation for each of the multiple magnetic markers 10 that belong to the magnetic detection area.

[0023] The marker system 1 of this example has one of its technical features in the manner in which the magnetic markers 10 are laid at the branching point 121 and the merging point 123. The control method of the vehicle 2 of this example has one of its technical features in the branching control from the main line 110 to the side road 120, and the merging control from the side road 120 to the main line 110. The branching control and merging control of this example are controls that utilize the manner in which the magnetic markers 10 are laid at the branching point 121 or the merging point 123.

[0024] (Magnetic marker installation) The magnetic markers 10 are laid at a branch point 121 from the main line 110 to the side road 120 as shown in Figure 5. At the branch point 121, a marker array line 124 on which the magnetic markers 10 are arranged on the side road 120 branches off diagonally from a marker array line 114 on which the magnetic markers 10 are arranged on the main line 110. At the branch point 121, the lateral distance between the magnetic markers 10 on the main line 110 and the magnetic markers 10 on the side road 120 gradually widens toward the direction of travel of the track 100. Here, the lateral direction means a direction that is approximately perpendicular to the route direction of the main line 110 and the side road 120, which are an example of a route.

[0025] The magnetic markers 10 are installed at the junction 123 where the side road 120 merges with the main road 110 as shown in Figure 6. At the junction 123, the marker array line 124 of the side road 120 connects diagonally to the marker array line 114 of the main road 110. At the junction 123, the lateral distance between the magnetic markers 10 on the main road 110 and the magnetic markers 10 on the side road 120 gradually decreases in the direction of travel of the track 100.

[0026] At the branching point 121 and the merging point 123, the closer you are to the branching point 118 or merging point 119 between the marker arrangement line 114 of the main road 110 and the marker arrangement line 124 of the side road 120, the shorter the spacing between two horizontally aligned magnetic markers 10 (the distance between two horizontally aligned magnetic markers 10).

[0027] If a certain distance is maintained between the two magnetic markers 10 arranged side by side, the distribution in the vehicle width direction of the magnetic measurement values ​​obtained by the magnetic sensor module 3 will be as shown in Fig. 7. With the magnetic distribution shown in Fig. 7, the peaks corresponding to the magnetic markers 10 can be distinguished, and each magnetic marker 10 can be detected.

[0028] On the other hand, if the distance between two side-by-side magnetic markers 10 becomes too narrow, it becomes more difficult to detect the peaks corresponding to each magnetic marker 10, as shown in the example of Fig. 8. This is because the magnetic distributions originating from each magnetic marker 10 overlap and become integrated. In the case of the magnetic distribution shown in the example of Fig. 8, it is possible to estimate the presence of a magnetic source, but it becomes more difficult to distinguish and detect each magnetic marker 10.

[0029] If the spacing between two horizontally arranged magnetic markers 10 is too narrow, it is advisable to combine them with different magnetic polarities. In this case, as shown in the distribution of magnetic measurement values ​​in Figure 9, a positive peak value appears corresponding to the magnetic marker 10N with a north pole, and a negative peak value appears corresponding to the magnetic marker 10S with a south pole. With this combination of magnetic markers 10N and 10S with different magnetic polarities, each magnetic marker 10 can be relatively easily distinguished and detected, even if the spacing between horizontally adjacent magnetic markers 10 is the same as in Figure 8.

[0030] The inventors have found the following through verification experiments and simulations: If the interval between horizontally adjacent magnetic markers 10 exceeds 0.3 m, the magnetic markers 10 can be easily distinguished and detected even if they have the same magnetic polarity. On the other hand, if the interval between horizontally adjacent magnetic markers 10 is 0.3 m or less, the processing load for distinguishing and detecting the magnetic markers 10 increases when the magnetic polarity is the same.

[0031] Therefore, in this example, the magnetic polarity combinations of the two magnetic markers 10 are set according to the horizontal distance as shown in Fig. 10. When the distance between the two magnetic markers 10 is 0.3 m or less, different magnetic polarity combinations are used, and when the distance between the two magnetic markers 10 is more than 0.3 m, the same magnetic polarity combination is used.

[0032] In this example, 0.3 m is used as an example of the predetermined threshold for switching between a combination of the same magnetic polarity and a combination of different magnetic polarities for two side-by-side magnetic markers 10. The predetermined threshold may be changed as appropriate, taking into consideration the detection performance of the magnetic sensor module 3, the magnetic characteristics of the magnetic marker 10, the detection algorithm for the magnetic marker 10, etc.

[0033] In this example, two magnetic markers 10 are installed side by side at the branching point 121 and the merging point 123. As described above, at the branching point 121, the distance between the two side-by-side magnetic markers 10 gradually increases from the branching point 118 onwards. At the branching point 121, just past the branching point 118 between the marker arrangement line 114 of the main line 110 and the marker arrangement line 124 of the side road 120, the distance between the magnetic markers 10 on the main line 110 and the magnetic markers 10 on the side road 120 is 0.3 m or less. Therefore, at the branching point 121, a magnetic marker 10S with a south pole is installed at the position on the marker arrangement line 124 of the side road 120 closest to the branching point 118.

[0034] As described above, at the merging point 123, the distance between the two side-by-side magnetic markers 10 gradually narrows toward the merging point 119. At the merging point 123, just before the merging point 119 where the marker array line 114 of the main line 110 and the marker array line 124 of the side road 120 meet, the distance between the magnetic markers 10 on the main line 110 and the magnetic markers 10 on the side road 120 is 0.3 m or less. For this reason, at the merging point 123, a magnetic marker 10S with a south pole is installed on the marker array line 124 of the side road 120 at a position just before the merging point 119.

[0035] (Branch control and merge control) Next, we will explain branch control and merging control, which are control methods for vehicle 2. Branch control is a control method that utilizes the installation mode of magnetic markers 10 at branch point 121 (see Figure 5). Merging control is a control method that utilizes the installation mode of magnetic markers 10 at merging point 123 (see Figure 6). Branch control and merging control will be explained with reference to the flow diagram in Figure 11.

[0036] While the vehicle 2 is traveling on the road 100, the control unit 20 controls the magnetic sensor module 3 to repeatedly execute the marker detection process. As described above, the marker detection process is a process that attempts to detect the magnetic marker 10, determines the magnetic polarity of the detected magnetic marker 10, and measures the lateral deviation of the vehicle 2 with respect to the magnetic marker 10.

[0037] When the control unit 20 acquires a processing result indicating that a magnetic marker 10 has been detected (S101: YES), it first determines whether two magnetic markers 10 have been detected simultaneously (S102). If two magnetic markers 10 have not been detected simultaneously but only one magnetic marker 10 has been detected independently (S102: NO), the control unit 20 acquires the lateral deviation from the magnetic marker 10 from the processing result of the marker detection process (S137). The vehicle 2 is subjected to steering control using the lateral deviation from the magnetic marker 10 as a control amount (S108).

[0038] If it is determined in step S102 above that two magnetic markers 10 have been detected simultaneously (S102: YES), the control unit 20 determines the combination of magnetic polarities of the two detected magnetic markers 10 (S103). Note that the processing results by the magnetic sensor module 3 when two magnetic markers 10 are detected simultaneously include information on the magnetic polarity of each magnetic marker 10 and two lateral deviations for each magnetic marker 10.

[0039] As described above, in the installation mode of the magnetic markers 10 in this example, among the magnetic markers 10 on the side road 120, a magnetic marker 10S with a south pole is installed in a position closest to the branch point 118 or the merging point 119. The other magnetic markers 10 on the side road 120 and all magnetic markers 10 on the main line 110 are magnetic markers 10N with a north pole. On the vehicle 2 side, based on the simultaneous detection of this south pole magnetic marker 10S and the north pole magnetic marker 10N on the main line 110 next to it, it can determine whether the vehicle has reached the branch point 121 (branch point 118) or the merging point 123 (merging point 119).

[0040] When entering the junction 123, simultaneous detection of two magnetic markers 10 with the same magnetic polarity occurs before simultaneous detection of two magnetic markers 10 with different magnetic polarity. When simultaneous detection of two magnetic markers 10 with the same magnetic polarity is followed by simultaneous detection of two magnetic markers 10 with different magnetic polarity, it can be determined that the junction 123 has been reached. On the other hand, when simultaneous detection of two magnetic markers 10 with different magnetic polarity occurs, it can be determined that the junction 121 has been reached if simultaneous detection of two magnetic markers 10 with the same magnetic polarity has not occurred prior to the simultaneous detection.

[0041] When the two simultaneously detected magnetic markers 10 have the same magnetic polarity (S102: YES → S103: SAME), the control unit 20 acquires, of the two lateral deviations for each magnetic marker 10, the lateral deviation that has a smaller difference from the control amount at the time of the most recent magnetic marker detection (the lateral deviation applied to the previous steering control) (S127). Selecting the lateral deviation that will be the control amount for the steering control corresponds to selecting the magnetic marker 10 to be followed. For example, if the vehicle 2 is traveling on the main road 110, the lateral deviation for the magnetic marker 10 on the main road 110 is acquired in step S127. For example, if the vehicle 2 is traveling on the side road 120, the lateral deviation for the magnetic marker 10 on the side road 120 is acquired in step S127. As a result, the vehicle 2 is controlled to steer so as to maintain its current traveling path 100 (S108).

[0042] On the other hand, in the above step S103, if the magnetic polarities of the two simultaneously detected magnetic markers 10 are different (S103: different), the control unit 20 determines whether the type of road on which the vehicle 2 is traveling is the main road 110 or the side road 120 (S104). Of the two lateral deviations from the two simultaneously detected magnetic markers 10N, 10S, the control unit 20 identifies the magnetic polarity of the magnetic marker 10 associated with the lateral deviation that has a smaller difference from the control amount (lateral deviation applied in the previous steering control) at the time of the most recent magnetic marker detection. If the lateral deviation is the lateral deviation from the magnetic marker 10N with a north pole on the main road 110, the type of road 100 on which the vehicle 2 is traveling can be determined to be the main road 110. On the other hand, if the lateral deviation that has a smaller difference from the control amount (lateral deviation applied in the previous steering control) at the time of the most recent magnetic marker detection is the lateral deviation from the magnetic marker 10S with a south pole, the type of road 100 on which the vehicle 2 is traveling can be determined to be the side road 120.

[0043] If it is determined in step S104 above that the vehicle is traveling on the side road 120 (S104: Side road), the control unit 20 can immediately determine that the two side-by-side magnetic markers 10 determined to have different magnetic polarities in step S103 above are installed at the merging point 123. In this case, the control unit 20 acquires the lateral deviation from the N-pole magnetic marker 10N on the main line 110, out of the two lateral deviations from the two side-by-side magnetic markers 10 with different magnetic polarities (S117). Then, by applying the lateral deviation from the N-pole magnetic marker 10N on the main line 110 to steering control, merging control for merging from the side road 120 onto the main line 110 is initiated (S108).

[0044] On the other hand, if it is determined in step S104 above that the vehicle is traveling on the main line 110 (S104: main line), the control unit 20 determines (S105) whether the vehicle is traveling at the branch point 121 or the merging point 123. As described above, whether the vehicle is traveling at the branch point 121 or the merging point 123 can be determined depending on whether simultaneous detection of two magnetic markers 10 with the same magnetic polarity occurs prior to simultaneous detection of two magnetic markers 10 with different magnetic polarities.

[0045] Next, the control unit 20 determines whether or not to branch off (S106). For example, if it is determined in step S105 that there is a merging point 123, it can immediately determine that there is no branch off. If there is no branch off (S106: NO), the lateral deviation of the main line 110 from the north pole magnetic marker 10N is acquired (S117), and steering control is executed using this lateral deviation as a control amount (S108). As a result, the vehicle 2 travels along the main line 110 and passes through the merging point 123.

[0046] For example, if the branch point 121 is determined in step S105 above and the second travel route (a travel route via the side road 120) is set for the vehicle 2, it can be determined in step S106 that the vehicle will branch. If the vehicle 2 is branching (S106: YES), the lateral deviation with respect to the magnetic marker 10S with the south pole among the magnetic markers 10 with different magnetic polarities simultaneously detected in step S103 above is acquired (S107). As described above, the magnetic marker 10S with the south pole is laid on the side road 120, and branch control is initiated to cause the vehicle 2 to branch onto the side road 120 (S108).

[0047] The control flow will be explained below for each driving pattern. (Driving pattern that passes through the fork) When a vehicle 2 traveling on the main line 110 approaches the branch point 121 and reaches the branch point 118 between the marker arrangement line 114 of the main line 110 and the marker arrangement line 124 of the side road 120 (symbol 2a in Figure 12), simultaneous detection of two magnetic markers 10 of different magnetic polarities occurs (symbol 2b in Figure 12).

[0048] When the travel route set for the vehicle 2 is the above-mentioned first travel route that does not pass through the side road 120, the control unit 20 executes steering control using the lateral deviation of the N-pole magnetic marker 10N of the main line 110 as the control amount. If the vehicle 2 travels further (reference symbol 2c in FIG. 12 ) and simultaneous detection of two magnetic markers 10 occurs regardless of the combination of magnetic polarities, steering control is continued using the lateral deviation of the N-pole magnetic marker 10N of the main line 110 as the control amount. As a result, the vehicle 2 is steered to travel on the main line 110 without entering the side road 120.

[0049] In the installation configuration shown in Figure 5 of this example, there is only one location at the branch point 121 where two magnetic markers 10 with different magnetic polarities are installed side by side. Alternatively, there may be multiple locations at the branch point 121 where two magnetic markers 10 with different magnetic polarities are installed side by side. In this case, simultaneous detection of two magnetic markers 10 with different magnetic polarities will occur continuously. In this case, steering control is performed using the lateral deviation of the N pole of the main line 110 from the magnetic marker 10N as the control amount.

[0050] As the vehicle 2 continues traveling after passing the junction 118, two magnetic markers 10 with the same magnetic polarity are simultaneously detected one or more times (see symbol 2c in Figure 12). The control unit 20 selects the lateral deviation from these two magnetic markers 10 that has the smaller difference from the control amount at the time of the most recent magnetic marker detection (the lateral deviation applied in the previous steering control). As a result, as in the previous steering control, the magnetic marker 10N on the main line 110 is selected as the target to follow, and the vehicle 2 continues traveling along the main line 110.

[0051] (branching driving patterns) When a vehicle 2 traveling on the main line 110 approaches the branch point 121 and reaches the branch point 118 between the marker arrangement line 114 of the main line 110 and the marker arrangement line 124 of the side road 120 (symbol 2a in Figure 13), simultaneous detection of two magnetic markers 10 of different magnetic polarities occurs (symbol 2b in Figure 13).

[0052] When the travel route set for the vehicle 2 is the second travel route passing through the side road 120, the control unit 20 executes steering control using the lateral deviation of the south pole of the side road 120 relative to the magnetic marker 10S as a control amount. As a result, the vehicle 2 is steered so as to branch off from the main road 110 and enter the side road 120 (branch control).

[0053] In addition, instead of the installation mode shown in Figure 5 in this example, it is also possible to install two magnetic markers 10 of different magnetic polarities side by side at multiple locations at the branch point 121. In this case, simultaneous detection of two magnetic markers 10 of different magnetic polarities will occur continuously. In this case, steering control is performed using the lateral deviation from the magnetic marker 10S of the south pole of the side road 120 as the control amount. The vehicle 2 is steered to follow the magnetic marker 10S of the south pole of the side road 120.

[0054] As the vehicle 2 passes the junction 118 and continues traveling, two magnetic markers 10 with the same magnetic polarity are simultaneously detected one or more times (see symbol 2c in Figure 13). The control unit 20 selects the lateral deviation from these two magnetic markers 10 that has the smaller difference from the control amount (the lateral deviation applied in the previous steering control) at the time of the most recent magnetic marker detection. As a result, the magnetic marker 10N on the side road 120 is selected as the target to follow, and the vehicle 2 is steered to enter the side road 120.

[0055] (Training pattern in which main line vehicles pass through the merging point) When a vehicle 2 traveling on the main road 110 approaches the merging point 123 and approaches the merging point 119 where the marker arrangement line 114 of the main road 110 and the marker arrangement line 124 of the side road 120 (symbol 2a in Figure 14), first, simultaneous detection of two magnetic markers 10 of the same magnetic polarity occurs.

[0056] Of the lateral deviations for these two magnetic markers 10 detected simultaneously, the control unit 20 selects the lateral deviation that has a smaller difference from the control amount at the time of the most recent magnetic marker detection (the lateral deviation applied in the previous steering control). As a result, as in the previous steering control, the magnetic marker 10N on the main line 110 is selected as the target to be followed, and the vehicle 2 is steered to continue traveling along the main line 110. In this way, while simultaneous detection of two magnetic markers 10 with the same magnetic polarity occurs once or multiple times, the vehicle 2 continues traveling along the main line 110.

[0057] As the vehicle 2 approaches the junction 119 (reference symbol 2b in FIG. 14), simultaneous detection of two magnetic markers 10 with different magnetic polarities occurs. In response to the simultaneous detection of two magnetic markers 10 with different magnetic polarities, the control unit 20 refers to the travel route set for the vehicle 2. If the travel route set for the vehicle 2 is the first travel route described above that does not pass through the side road 120, the control unit 20 performs steering control using the lateral deviation of the main line 110 from the N-pole magnetic marker 10N as the control amount. As a result, the vehicle 2 is steered to continue traveling on the main line 110 and passes through the junction 123.

[0058] In the installation mode shown in Figure 6 of this example, there is only one location at the merging point 123 where two magnetic markers 10 with different magnetic polarities are installed side by side. Alternatively, there may be multiple locations at the merging point 123 where two magnetic markers 10 with different magnetic polarities are installed side by side. In this case, simultaneous detection of two magnetic markers 10 with different magnetic polarities will occur continuously. In this case, steering control can be performed using the lateral deviation from the N-pole magnetic marker 10N on the main line 110 as the control amount. The vehicle 2 is steered to follow the N-pole magnetic marker 10N on the main line 110.

[0059] (Travel pattern in which vehicles on side roads merge onto the main road) When a vehicle 2 traveling on a side road 120 approaches a merging point 123 and approaches the merging point 119 where the marker arrangement line 114 of the main road 110 and the marker arrangement line 124 of the side road 120 (symbol 2a in Figure 15), first, simultaneous detection of two magnetic markers 10 of the same magnetic polarity occurs.

[0060] Of the lateral deviations for these two magnetic markers 10 detected simultaneously, the control unit 20 selects the lateral deviation that has a smaller difference from the control amount at the time of the most recent magnetic marker detection (the lateral deviation applied in the previous steering control). As a result, as in the previous steering control, the magnetic marker 10N on the side road 120 is selected as the target to be followed, and the vehicle 2 is steered to travel along the side road 120. In this way, while simultaneous detection of two magnetic markers 10 with the same magnetic polarity occurs once or multiple times, the vehicle 2 is steered to continue traveling along the side road 120.

[0061] As the vehicle 2 approaches the merging point 119 (symbol 2b in FIG. 15), two magnetic markers 10 with different magnetic polarities are detected simultaneously. The control unit 20 determines that the vehicle 2 has reached the merging point 123 via the side road 120, and starts merging control by switching the target to be tracked to the magnetic marker 10N with the N pole on the main road 110.

[0062] In addition, instead of the installation mode shown in Figure 6 of this example, it is also possible to install two magnetic markers 10 of different magnetic polarities side by side at multiple locations at the merging point 123. In this case, simultaneous detection of two magnetic markers 10 of different magnetic polarities will occur continuously. In this case, steering control can be performed using the lateral deviation from the N-pole magnetic marker 10N on the main line 110 as the control amount. The vehicle 2 is steered to follow the N-pole magnetic marker 10N on the main line 110.

[0063] When the vehicle 2 reaches the junction 119 (reference symbol 2c in FIG. 15), simultaneous detection of the two magnetic markers 10 ends, and only one magnetic marker 10 on the main line 110 is detected. The control unit 20 performs steering control using the lateral deviation from this magnetic marker 10 as the control amount. This allows the vehicle 2 to travel while following the main line 110.

[0064] As described above, one of the technical features of the marker system 1 of this example is the combination of magnetic polarities of two magnetic markers 10 that are laid on different routes and arranged side by side. The combination of magnetic polarities of the two side by side magnetic markers 10 differs depending on whether the distance between the two magnetic markers 10 is equal to or less than a predetermined threshold. When the distance between the two magnetic markers 10 is equal to or less than the predetermined threshold, the combination of magnetic polarities is different, whereas when the distance between the two magnetic markers 10 is equal to or greater than the predetermined threshold, the combination of magnetic polarities is the same.

[0065] The closer two magnetic markers 10 are arranged side by side, the greater the possibility of magnetic interference occurring. If the two magnetic markers 10 have the same magnetic polarity, the magnetic interference caused by the two magnetic markers 10 will broaden the magnetic distribution, potentially making it difficult to detect a peak that would occur directly above the magnetic marker 10. On the other hand, if the magnetic polarities of the two magnetic markers 10 arranged side by side are different, it will be easier to detect the peak of the magnetic distribution even if magnetic interference occurs, and each magnetic marker 10 can be detected with high reliability.

[0066] The control method of this example is a control method that, when the vehicle 2 branches off from a route that forms the main line 110, is triggered by the simultaneous detection of two magnetic markers 10 with different magnetic polarities, causing the vehicle 2 to enter a side road 120 (one example of a route) that branches off from the route that forms the main line 110. The control method of this example is also an example of a control method that, when the vehicle 2 merges with a route that forms the main line 110, is triggered by the simultaneous detection of two magnetic markers 10 with different magnetic polarities, causing the vehicle 2 to enter from the side road 120 onto the route that forms the main line 110.

[0067] In the configuration of this example, north pole magnetic markers 10N are installed on the road 100 except for the branch point 121 and the merging point 123. Therefore, the south pole magnetic markers 10S installed at the branch point 121 and the merging point 123 can be a trigger for starting branch control or merging control. By utilizing the south pole magnetic markers 10S installed on the side roads 120 of the branch point 121 and the merging point 123, the control unit 20 can start branch control or merging control at an extremely appropriate timing.

[0068] Magnetic markers 10 of different magnetic polarities laid at branching points 121 and merging points 123 indicate with high precision the positions of the junctions (branching points 118, merging points 119) between the marker arrangement line 114 of the main line 110 and the marker arrangement line 124 of the side road 120. By detecting magnetic markers 10 of different magnetic polarities, the vehicle 2 can determine without delay when it has reached the junction between the marker arrangement line 114 of the main line 110 and the marker arrangement line 124 of the side road 120, and can perform branching control or merging control at near-optimal timing.

[0069] Example 2 This example is an example of a marker system 1 based on the configuration of the first embodiment and applied to a road 100 with a complex route structure. The details of this example will be described with reference to FIGS. The road 100 in this example (FIG. 16) is a road with multiple branch points 121 and merging points 123. The marker system 1 applied to this road 100 includes a server device that can be accessed by a vehicle 2 via wireless communication.

[0070] A database is constructed in the server device, in which attribute information of at least a specific magnetic marker 10 is recorded. The specific magnetic marker 10 is a magnetic marker that has a different magnetic polarity from the magnetic markers 10 next to it at the branching point 121 and the merging point 123. In the database, the attribute information of the corresponding magnetic marker 10 is recorded, linked to the identification information of the magnetic marker 10. The attribute information is, for example, information indicating the type of the branching point 121 or the merging point 123, or information indicating the position of the branching point 121 or the merging point 123. By referring to the database using the identification information of the magnetic marker 10, it is possible to identify the branching point 121 or the merging point 123.

[0071] The two magnetic markers 10 arranged side by side with different magnetic polarities are both the above-mentioned specific magnetic markers 10. At least one of these two magnetic markers 10 is a magnetic marker with an RFID tag 10T attached to its end surface (FIG. 17). The tag information output by the RFID tag 10T is information that can uniquely identify the corresponding magnetic marker 10 and can be used as identification information for that magnetic marker 10.

[0072] Although not shown, the vehicle 2 in this example is equipped with a tag reader that reads tag information from the RFID tag 10T and a wireless communication circuit for accessing a database in a server device. Furthermore, the vehicle 2 is equipped with a storage device that stores information about a preset route. The route information includes information that identifies the branch points 121 to be passed, the branch points 121 where the vehicle branches, the merging points 123 to be passed, and the merging points 123 where the vehicle merges.

[0073] When the vehicle 2 reaches the branch point 121 or the merging point 123, it reads the tag information of the RFID tag 10T attached to the specific magnetic marker 10. Using this tag information, which is the identification information of the magnetic marker 10, the vehicle 2 accesses a server device and acquires attribute information linked to this tag information (identification information). As described above, this attribute information is, for example, information indicating the type of the branch point 121 or the merging point 123, or information indicating the position of the branch point 121 or the merging point 123, etc.

[0074] The vehicle 2 determines whether to branch off or merge at the branch point 121 or the merging point 123 where the magnetic marker 10 related to the acquired attribute information is located, based on information about a preset travel route. The vehicle 2 then executes branching control or merging control as appropriate depending on the result of the determination. The other configurations and effects are the same as those of the first embodiment.

[0075] Example 3 In this example, the magnetic polarity of the magnetic markers 10 laid on the track 100 is changed based on the marker system of Example 1. This will be explained with reference to Figures 18 to 20. In the marker system 1 of this example, the magnetic polarity of the magnetic markers 10 is random, except for some marker placement positions 10D (Figures 18 and 19) belonging to the branching point 121 and merging point 123.

[0076] Some marker installation positions 10D are installation positions of magnetic markers 10 that may be detected simultaneously with other magnetic markers 10 next to them. In this example, the installation positions of magnetic markers 10 where the spacing between other magnetic markers 10 next to them is less than 2.3 m, the width of the vehicle 2, are designated as marker installation positions 10D. Marker installation positions 10D are locations where the magnetic polarity of the magnetic markers 10 to be installed is managed.

[0077] Furthermore, among the marker installation positions 10D, those marker installation positions 10D that are spaced 0.3 m or less from other horizontally adjacent marker installation positions 10D are positions where magnetic markers 10 with a different magnetic polarity than the other horizontally adjacent magnetic markers 10 are installed. Note that there is no specification as to which of the magnetic markers 10 installed on the main line 110 and the side road 120 has a north pole or a south pole. It is sufficient that the magnetic polarities of the two horizontally adjacent magnetic markers 10 are different.

[0078] Among the marker installation positions 10D, those marker installation positions 10D that are spaced apart from other horizontally adjacent marker installation positions 10D by more than 0.3 m and less than 2.3 m are positions where magnetic markers 10 with the same magnetic polarity as the other horizontally adjacent magnetic markers 10 are installed. Note that the magnetic polarity of the two horizontally adjacent magnetic markers 10 is arbitrary, as long as the magnetic polarity of these two magnetic markers 10 is the same.

[0079] In the case of Figure 18 illustrating a branch point 121, marker installation position 10D on the main line 110 and marker installation position 10D on the side road 120 immediately after passing the branch point 118 are positions where magnetic markers 10 with a different magnetic polarity than the magnetic markers 10 next to them are installed. Then, marker installation positions 10D on the main line 110 and marker installation positions 10D on the side road 120, which are the second to fourth positions after passing the branch point 118, are positions where magnetic markers 10 with the same magnetic polarity as the other magnetic markers 10 next to them are installed.

[0080] In the case of Figure 19 illustrating a merging point 123, marker installation position 10D on the main line 110 and marker installation position 10D on the side road 120 just before the merging point 119 are positions where magnetic markers 10 with a different magnetic polarity than the other magnetic markers 10 next to them are installed. Then, just before the merging point 119, the second to fourth marker installation positions 10D on the main line 110 and marker installation positions 10D on the side road 120 are positions where magnetic markers 10 with the same magnetic polarity as the other magnetic markers 10 next to them are installed.

[0081] The control by the marker system 1 of this example will be described with reference to the flow diagram of Figure 20. When the control unit 20 acquires a processing result including the detection of a magnetic marker 10 (S201: YES), it first determines whether two magnetic markers 10 were detected simultaneously (S202). If one magnetic marker 10 was detected independently rather than two simultaneously (S202: NO), the control unit 20 acquires the lateral deviation relative to the magnetic marker 10 from the processing result of the marker detection process (S236). The vehicle 2 travels by steering control using the lateral deviation acquired in this way as a control amount (S209).

[0082] In this way, the control of the vehicle 2 traveling on the main road 110 or the side road 120 other than the branch point 121 and the merging point 123 is exactly the same as in Example 1. However, in the processing of this example, step S237 is added following the above step S236, in which flags A and B are reset to zero.

[0083] Flag A is a control flag that indicates the occurrence of simultaneous detection of two magnetic markers 10 of the same magnetic polarity. In the configuration of this example, when two magnetic markers 10 of different magnetic polarities are detected simultaneously, flag A is used to determine whether the two magnetic markers 10 belong to a branch point 121 or a merging point 123. Flag B is a control flag that indicates that branch control or merging control has begun. Flags A and B are reset to zero when the vehicle 2 passes the branch point 121 or the merging point 123. Before the vehicle 2 enters the branch point 121 or the merging point 123, both flags A and B are reset to zero.

[0084] When two magnetic markers 10 are detected simultaneously (S202: YES), first, the value of flag B, which indicates that branch control or merging control has started, is determined (S203). When flag B is 1, i.e., when branch control or merging control has started (S203: 1), step S216 is executed. In this step S216, of the two lateral deviations for the two simultaneously detected magnetic markers 10, the lateral deviation that has the smaller difference from the control amount at the time of the most recent magnetic marker detection (the lateral deviation applied to the previous steering control) is acquired. The processing of step S216 is executed regardless of the combination of magnetic polarities of the two simultaneously detected magnetic markers 10. Then, the vehicle 2 is steered using the lateral deviation acquired in this way as the control amount (S209).

[0085] On the other hand, if flag B is zero in step S203, i.e., branching control and merging control have not been initiated (S203: 0), the combination of magnetic polarities of the two simultaneously detected magnetic markers 10 is determined (S204). If the magnetic polarities of the two simultaneously detected magnetic markers 10 are the same (S202: YES → S203: 0 → S204: same), step S226 is executed. In this step S226, of the two lateral deviations for the two simultaneously detected magnetic markers 10, the lateral deviation that has the smaller difference from the control amount at the time of the most recent magnetic marker detection (the lateral deviation applied to the previous steering control) is acquired.

[0086] The processing of step S226 is the same as the processing of step S216 described above. The difference between step S226 and step S216 is whether step S226 is followed by step S227 in which 1 is assigned to flag A. After 1 is assigned to flag A (S227), the vehicle 2 is subjected to steering control using the lateral deviation acquired in step S226 as the control amount (S209).

[0087] On the other hand, if the magnetic polarities of the two magnetic markers 10 detected simultaneously before the start of branch control and merge control are different (S202: YES → S203: 0 → S204: different), the control unit 20 first determines the value of flag A (S205). Flag A indicates whether or not simultaneous detection of two magnetic markers 10 with the same magnetic polarity has occurred previously. If simultaneous detection of two magnetic markers 10 with the same magnetic polarity has occurred previously, that is, when entering the merge point 123, flag A is assigned a value of 1 in step S227 above. On the other hand, when entering the branch point 121, simultaneous detection of two magnetic markers 10 with the same magnetic polarity does not occur prior to simultaneous detection of two magnetic markers 10 with different magnetic polarities, so flag A remains zero.

[0088] Therefore, when flag A is zero (S205:0), it can be determined that the vehicle has entered the branch point 121 rather than the merging point 123. In response to the entry into the branch point 121, the control unit 20 determines whether or not to branch (S206). When a second travel route (a travel route via the side road 120) is set for the vehicle 2, the control unit 20 determines that the vehicle will branch.

[0089] If the travel route of the vehicle 2 branches (S206: YES), the control unit 20 starts branching control by switching the magnetic marker 10 to be followed in step S207. In step S207, of the two lateral deviations for the two simultaneously detected magnetic markers 10, the lateral deviation that has the larger difference from the control amount at the time of the most recent magnetic marker detection (the lateral deviation applied to the previous steering control) is obtained, and the magnetic marker 10 to be followed is switched from the magnetic marker 10 on the main road 110 to the magnetic marker 10 on the side road 120. Then, in response to this switching of the magnetic marker 10 to be followed, branching control is started and flag B is set to 1 (S208).

[0090] If, after branch control is initiated in this manner, two magnetic markers 10 of different magnetic polarities are subsequently detected simultaneously, flag B is set to 1, and therefore step S207 described above will not be executed again. In this case, step S216 described above is immediately executed based on the determination made in step S203. In step S216, of the two lateral deviations for the two simultaneously detected magnetic markers 10, the smaller difference from the control amount at the time of the most recent magnetic marker detection (the lateral deviation applied to the steering control obtained in the previous step S207) is obtained. In other words, the magnetic marker 10 on the side road 120 that was set as the target to be followed in response to the start of branch control in the previous step S207 is maintained as the target to be followed.

[0091] If it is determined in step S206 above that there is no branch (S206: NO), the process proceeds to step S216, where the difference between the two lateral deviations for the two simultaneously detected magnetic markers 10 and the control amount at the most recent magnetic marker detection (the lateral deviation applied to the steering control obtained in the previous step S207) is obtained. In other words, the magnetic marker 10 on the main line 110 is maintained as the target to be followed.

[0092] If the vehicle 2 passes through the branch point 121 without any change, the simultaneous detection of magnetic markers 10 of the same magnetic polarity occurs (S201 → S202: YES). In this case, because branch control has not been initiated, flag B is zero. If two magnetic markers 10 of the same magnetic polarity are detected simultaneously (S204: SAME), the process proceeds to step S226, and the state of following the magnetic marker 10 on the main line 110 is maintained. Then, in the following step S227, flag A is set to 1. At the branch point 121, the marker arrangement line 114 on the main line 110 and the marker arrangement line 124 on the side road 120 fan outward. Therefore, after step S227 is executed, simultaneous detection of two magnetic markers 10 of different magnetic polarities does not occur while passing through the branch point 121, and the process following step S204: DIFFERENT is not executed. Therefore, the vehicle 2 can travel along the main line 110 and pass through the branch point 121.

[0093] On the other hand, in step S205, which is executed in response to the simultaneous detection of two magnetic markers 10 of different magnetic polarities before the start of branch control and merging control, if flag A is 1, i.e., in the case of entering the merging point 123 (S205:1), the control unit 20 determines whether to merge in step S215. When a second driving route is set for the vehicle 2, the control unit 20 determines that the vehicle 2 will merge.

[0094] If the travel route of the vehicle 2 requires merging (S215: YES), the control unit 20 starts merging control by switching the magnetic marker 10 to be followed in step S207. Specifically, of two lateral deviations for two simultaneously detected magnetic markers of different magnetic polarities, the control unit 20 acquires the lateral deviation that has a larger difference from the control amount (the lateral deviation applied to the previous steering control) at the time of the most recent magnetic marker detection. As a result, the magnetic marker 10 to be followed is switched from the magnetic marker 10 on the side road 120 to the magnetic marker 10 on the main road 110. Then, merging control is started in response to this switching of the magnetic marker 10 to be followed, and 1 is assigned to flag B (S208).

[0095] If, after the merging control is started in this way, two magnetic markers 10 of different magnetic polarities are subsequently detected simultaneously, flag B is set to 1, and therefore step S207 described above will not be executed again. In this case, step S216 described above is immediately executed based on the determination made in step S203. In step S216, of the two lateral deviations for the two simultaneously detected magnetic markers 10, the difference that is smaller than the control amount at the time of the most recent magnetic marker detection (the lateral deviation applied to the steering control obtained in the previous step S207) is obtained. In other words, the magnetic marker 10 on the main line 110 that was set as the target to be followed in response to the start of the merging control in the previous step S207 is maintained as the target to be followed.

[0096] On the other hand, if it is determined in step S215 that the vehicles 2 will not merge (S215: NO), of the two lateral deviations for the two simultaneously detected magnetic markers 10 with different magnetic polarities, the lateral deviation that has the smaller difference from the control amount at the most recent magnetic marker detection (the lateral deviation applied to the previous steering control) is acquired (S216), and steering control is executed (S208). In other words, the state in which the vehicle 2 travels along the main lane 110 is maintained as is. The other configurations and effects are the same as those of the first embodiment.

[0097] Although specific examples of the present invention have been described in detail as examples, these examples merely disclose examples of the technology encompassed by the claims. Needless to say, the scope of the claims should not be interpreted as being limited by the configurations, numerical values, etc. of the specific examples. The claims encompass technologies that are obtained by variously modifying, changing, or appropriately combining the specific examples using publicly known technology and the knowledge of those skilled in the art. [Explanation of symbols]

[0098] 1. Marker System 10 Magnetic Markers 10D Marker placement position 10N North Pole Magnetic Marker 10S South pole magnetic marker 100 Runway (Route) 110 Main Line 114, 124 marker array lines 118 Branching Point 119 Confluence 120 Side Roads (branching and merging routes) 121 Branching Point 123 Confluence 2 vehicles 20 Control Unit 3 Magnetic Sensor Module

Claims

1. A marker system in which magnetic markers are spaced along a route traveled by a vehicle, comprising: In a combination of two magnetic markers that are laid on different routes and are adjacent to each other in a horizontal direction perpendicular to the route direction, the combination of magnetic polarities differs depending on whether the distance between the two magnetic markers is equal to or less than a predetermined threshold value, If the distance between the two magnetic markers is equal to or less than a predetermined threshold, the magnetic polarity combination is a different magnetic polarity combination; A marker system in which the magnetic polarity combination is the same when the distance between the two magnetic markers exceeds or is equal to or greater than a predetermined threshold.

2. 2. The method according to claim 1, further comprising: recording attribute information of magnetic markers installed on the route in a database; The combination of two magnetic markers includes a combination of a magnetic marker installed on a route that forms a main line and a magnetic marker installed on a route that branches off from the route that forms the main line, and the combination of two magnetic markers includes a combination of two magnetic markers whose separation distance is equal to or less than a predetermined threshold value; In the database, attribute information indicating a branch point is recorded in at least one of the two magnetic markers.

3. 2. The method according to claim 1, further comprising: recording attribute information of magnetic markers installed on the route in a database; The combination of two magnetic markers includes a combination of a magnetic marker installed on a route that forms a main line and a magnetic marker installed on a route that merges with the route that forms the main line, and the combination of two magnetic markers includes a combination of two magnetic markers whose separation distance is equal to or less than a predetermined threshold value; In the database, attribute information indicating a merging point is recorded for at least one of the two magnetic markers.

4. 1. A control method for driving a vehicle along a route having spaced apart magnetic markers, comprising: In a combination of two magnetic markers that are laid on different routes and are adjacent to each other in a horizontal direction perpendicular to the route direction, the combination of magnetic polarities differs depending on whether the distance between the two magnetic markers is equal to or less than a predetermined threshold value, If the distance between the two magnetic markers is equal to or less than a predetermined threshold, the magnetic polarity combination is a different magnetic polarity combination; If the distance between the two magnetic markers exceeds a predetermined threshold or is equal to or greater than the predetermined threshold, the magnetic polarity combination is the same. The combination of two magnetic markers includes a combination of a magnetic marker installed on a route that forms a main line and a magnetic marker installed on a route that branches off from the main line, and the distance between the two magnetic markers is equal to or less than a predetermined threshold value; the vehicle has a magnetic detection area that is long in the vehicle width direction and a magnetic detection circuit that can simultaneously detect two magnetic markers that are adjacent in the laterally direction; A control method in which, when a vehicle branches off from a route that constitutes the main line, the simultaneous detection of two magnetic markers with different magnetic polarities triggers the start of control for the vehicle to enter a route that branches off from the route that constitutes the main line.

5. 5. The steering control system according to claim 4, wherein each time the magnetic marker is detected, the steering control is performed using the lateral deviation of the vehicle with respect to the detected magnetic marker as a control amount. When two magnetic markers with different magnetic polarities are detected simultaneously when the vehicle is branching off from the main route, a steering control is executed in which the control amount is one of two lateral deviations relative to the two magnetic markers that has a larger difference from the lateral deviation that was the control amount at the time of the most recent magnetic marker detection, thereby starting a control to cause the vehicle to enter the route branching off from the main route; After the control is started, when two magnetic markers are detected simultaneously, regardless of whether they have the same or different magnetic polarity, the control method executes steering control using the lateral deviation that has the smaller difference from the lateral deviation that was the control amount at the time of the most recent magnetic marker detection as the control amount.

6. 1. A control method for driving a vehicle along a route having spaced apart magnetic markers, comprising: In a combination of two magnetic markers that are laid on different routes and are adjacent to each other in a horizontal direction perpendicular to the route direction, the combination of magnetic polarities differs depending on whether the distance between the two magnetic markers is equal to or less than a predetermined threshold value, If the distance between the two magnetic markers is equal to or less than a predetermined threshold, the magnetic polarity combination is a different magnetic polarity combination; If the distance between the two magnetic markers exceeds a predetermined threshold or is equal to or greater than the predetermined threshold, the magnetic polarity combination is the same. The combination of two magnetic markers includes a combination of a magnetic marker installed on a route that forms a main line and a magnetic marker installed on a route that merges into the route that forms the main line, and the combination of two magnetic markers includes a combination of two magnetic markers whose distance apart is equal to or less than a predetermined threshold value; the vehicle has a magnetic detection area that is long in the vehicle width direction and a magnetic detection circuit that can simultaneously detect two magnetic markers that are adjacent in the laterally direction; A control method in which, when a vehicle is to merge from the merging route to the main route, control for merging the vehicle from the merging route to the main route is initiated when two magnetic markers with different magnetic polarities are detected simultaneously.

7. 7. The steering control system according to claim 6, wherein each time the magnetic marker is detected, the steering control is performed using the lateral deviation of the vehicle with respect to the detected magnetic marker as a control amount. When two magnetic markers with different magnetic polarities are detected simultaneously when a vehicle is merging from a merging route onto a main route, control is initiated to merge the vehicle from the merging route onto the main route by executing steering control in which the control amount is one of two lateral deviations relative to the two magnetic markers that has a larger difference from the lateral deviation that was the control amount when the most recent magnetic marker was detected, After the control is started, when two magnetic markers are detected simultaneously, regardless of whether they have the same or different magnetic polarity, the control method executes steering control using the lateral deviation that has the smaller difference from the lateral deviation that was the control amount at the time of the most recent magnetic marker detection as the control amount.

Images