Setting method for target trajectory

Abstract

To provide a method for efficiently setting a highly accurate target trajectory for causing a vehicle to travel along a course on which magnetic markers are arranged.SOLUTION: A method for setting a target trajectory includes: a scribing step P1 of acquiring a planned line for laying magnetic markers on a traveling road so that traveling vehicles can be detected; a laying step P2 of laying magnetic markers at intervals along the planned line; a survey step P3 of acquiring laying positions of the magnetic markers; a plotting step P4 of plotting the laying positions of the magnetic markers as marker positions on a map; and a target trajectory generation step P5 of obtaining a curve passing through the marker positions as a target trajectory. In the plotting step P4, the marker positions are plotted such that an interval between the marker positions at an end part of a straight road adjacent to a curved road is narrower than that at an intermediate part of the straight road.SELECTED DRAWING: Figure 3

Description

Technical Field

[0001] The present invention relates to a method for setting a target trajectory for running a vehicle along a runway.

Background Art

[0002] Conventionally, for example, a system for automatically running a vehicle using magnetic markers arranged along a runway is known (see, for example, Patent Document 1 below). A vehicle constituting this system includes, for example, a magnetic detection unit in which a plurality of magnetic sensors are arranged in the vehicle width direction. A vehicle equipped with such a magnetic detection unit can detect a magnetic marker during running and can specify the amount of lateral displacement (deviation in the vehicle width direction, lateral deviation) of the vehicle with respect to the magnetic marker. For example, by controlling the steering wheel of the vehicle so as to suppress the amount of lateral displacement of the vehicle with respect to the magnetic marker, automatic running of the vehicle along the runway can be realized.

[0003] In the above system, magnetic markers are arranged at intervals along the runway. When only the amount of lateral displacement with respect to the magnetic marker is the control target, there is a possibility that the vehicle may wobble between adjacent magnetic markers in the runway direction. In order to suppress the wobbling of the vehicle, the arrangement interval of the magnetic markers may be narrowed. However, if the interval of the magnetic markers is narrowed, the required number of magnetic markers increases, and the cost on the infrastructure side is likely to increase.

[0004] Therefore, a system has been proposed in which a target trajectory when the vehicle runs is set for a runway in which magnetic markers are arranged at intervals (see, for example, Patent Document 2 below). For a vehicle equipped with a function of positioning the position by inertial navigation, the amount of lateral displacement of the vehicle with respect to the target trajectory can also be estimated in the section of the gap between adjacent magnetic markers. In positioning by inertial navigation, the positioning error accumulates as the vehicle runs, while the positioning error can be reset by detecting a magnetic marker. For a system that adopts a combination of a magnetic marker and a target trajectory, it is possible to improve the accuracy when the vehicle runs along the runway.

Prior Art Documents

Patent Document

[0005]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0006] However, in a system that adopts a combination of a magnetic marker and a target trajectory, there are the following problems. That is, when the accuracy of the target trajectory combined with the magnetic marker is not sufficient, there is a problem that it is difficult to sufficiently improve the traveling accuracy of the vehicle.

[0007] The present invention has been made in view of the above-mentioned conventional problems, and aims to provide a method for efficiently setting a highly accurate target trajectory for driving a vehicle along a road on which magnetic markers are arranged.

Means for Solving the Problems

[0008] The present invention is a method for setting a target trajectory for controlling a vehicle to travel along a road composed of a straight road and a curved road, a planned line acquisition step of acquiring a planned line for laying magnetic markers on the road so that a traveling vehicle can be detected; a laying step of laying magnetic markers at intervals along the planned line; a laying position acquisition step of acquiring the laying positions of the magnetic markers laid on the road; a plotting step of plotting the laying positions of the magnetic markers on a map as marker positions; a target trajectory calculation step of obtaining, on the map on which the marker positions are plotted, a curve passing through the marker positions as the target trajectory, and includes In the plotting step, the marker positions are plotted such that the interval between the marker positions at the end of the straight path adjacent to the curved path is narrower than that at the middle of the straight path, in the method for setting a target trajectory.

Effect of the Invention

[0009] In the method for setting a target trajectory of the present invention, on a map where the laying positions of magnetic markers are plotted as marker positions, a curve passing through the marker positions is obtained as the target trajectory. One of the technical features of the method for setting a target trajectory of the present invention is that at the end of a straight path adjacent to a curved path, the marker positions are plotted at an interval narrower than that corresponding to the middle of the straight path.

[0010] At the end of a straight path, the target trajectory tends to protrude toward the side corresponding to the outer peripheral side of the adjacent curved path. By plotting the marker positions at a narrow interval at the end of the straight path, such a tendency can be suppressed. At the middle of the straight path, since the interval between the marker positions can be widened, the number of magnetic markers to be laid can be reduced, and the cost can be suppressed.

[0011] As described above, according to the method for setting a target trajectory of the present invention, it is possible to efficiently set a target trajectory for allowing a vehicle to travel with high accuracy.

Brief Description of the Drawings

[0012]

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Mode for Carrying Out the Invention

[0013] The embodiments of the present invention will be specifically described below using the following examples. (Example 1) This example relates to a method for setting a target trajectory 1T when the vehicle 2 automatically travels along the runway 100. This content will be described with reference to FIGS. 1 to 10.

[0014] The vehicle system 1 (FIG. 1) in this example is a system in which the vehicle 2 automatically travels on a runway 100 provided in an indoor environment such as a factory or a logistics warehouse, or an outdoor environment within the site of a factory, etc. The width of the illustrated runway 100 is 2 m 50 cm. Magnetic markers 10 are laid on the runway 100 at intervals along the direction of the runway.

[0015] The runway 100 illustrated in FIG. 1 is, for example, a one-way passage forming a substantially rectangular loop. Curved paths 100C are provided at the corners of the substantially rectangular loop. According to the curved paths 100C, the corners between the upstream straight path 100S and the downstream straight path 100S that intersect each other can be rounded.

[0016] In the configuration (FIG. 1) of this example, among the four corners in the runway 100, the curvature of the curved paths 100C is different between the two corners on the left side and the two corners on the right side in the figure. The curved paths 100C at the two corners on the left side have a larger curvature (a smaller radius of curvature) and a sharper curve. The radius of curvature of the curved paths 100C at the two corners on the left side is 2 m, and the radius of curvature of the curved paths 100C at the two corners on the right side is 5 m.

[0017] The vehicle 2 in this example is, as shown in FIGS. 1 and 2, for example, a transport vehicle that transports various articles. The vehicle 2 has operating means such as a steering wheel, an accelerator, and a brake. The vehicle 2 can travel by manual operation of these operating means. Although not shown, the vehicle 2 includes a plurality of actuators that drive these operating means systems, a control unit that controls these actuators, etc. The vehicle 2 can travel by manual operation by an operator (driver), and can also travel automatically under the control of the control unit.

[0018] Vehicle 2 is a four-wheel vehicle with front-wheel steering, having a vehicle body length of 2 m and a vehicle width of 1 m. Vehicle 2 is configured to be capable of autonomous driving by using the magnetic marker 10 laid on the road 100. Vehicle 2 is equipped with a magnetic sensor module 3 for detecting the magnetic marker 10. The magnetic sensor module 3 is attached to the rearmost part of Vehicle 2.

[0019] The magnetic sensor module 3 (Fig. 2) is a rod-shaped sensor unit in which a plurality of magnetic sensors (not shown) are incorporated at intervals. The magnetic sensor module 3 is attached to Vehicle 2 such that its longitudinal direction is along the vehicle width direction. The length of the rod-shaped magnetic sensor module 3 is close to the vehicle width of Vehicle 2. According to the magnetic sensor module 3 that is long in the vehicle width direction, the magnetic marker 10 can be detected with high certainty regardless of the lateral deviation of Vehicle 2 on the road 100.

[0020] In this example, a method for setting a target trajectory 1T for Vehicle 2 to travel on the road 100 will be described. In the method of this example, the target trajectory 1T is set by using the magnetic marker 10 laid along the road 100. The method for setting the target trajectory 1T in this example includes, as shown in Fig. 3, a step P1 of marking the travel trajectory 1T of Vehicle 2 on the road surface, a step P2 of constructing the magnetic marker 10, a step P3 of surveying the laying position of the magnetic marker 10, a step P4 of plotting the marker position 10P, and a step P5 of generating the target trajectory 1T. Hereinafter, the contents of each step will be described in order. Further, as a step not shown in Fig. 3, the content of a target trajectory correction step for correcting the target trajectory 1T will be described.

[0021] (1) Marking step The marking step P1 (Fig. 3) is a step of marking the travel line 2L of Vehicle 2 on the road surface (see Fig. 4). The marking step P1 constitutes an example of a planned line acquisition step of acquiring the travel line 2L (an example of a planned line) for laying the magnetic marker 10 on the road 100.

[0022] The travel line 2L is the travel trajectory when the vehicle 2 travels manually along the road 100. The marking process P1 in this example is carried out using the vehicle 2 (see Fig. 4) equipped with the red food coloring dropping device 25. The dropping device 25 is attached at a position corresponding to the center of the magnetic sensor module 3. While the vehicle 2 is traveling manually, the dropping device 25 drops the red food coloring onto the road surface. Thereby, the travel line 2L made of the red food coloring can be marked on the road surface. Note that during the marking process P1, it is advisable for an operator with good driving skills to drive the vehicle 2. Instead of manual driving, the marking process P1 may be carried out using a vehicle that travels by automatic driving based on inertial navigation.

[0023] (2) Construction process of magnetic markers The construction process P2 of magnetic markers (Fig. 3) is a process of laying the magnetic markers 10 on the travel line 2L by the marking process P1 (see Fig. 5). This construction process P2 forms an example of a laying step of laying the magnetic markers 10 at intervals along the travel line 2L which is an example of a planned line.

[0024] In the configuration of this example, the method of defining the interval between the magnetic markers 10 is different between the straight road 100S and the curved road 100C. On the straight road 100S, the interval between the magnetic markers 10 is defined by the distance. On the other hand, on the curved road 100C, the interval between the magnetic markers 10 is defined by the angle. In the configuration of this example, the angular interval of the magnetic markers 10 on the curved road 100C is constant regardless of the curvature (radius of curvature). In this example, the interval between the magnetic markers on the curved road 100C is set to 45 degrees.

[0025] Among the straight sections 100S, the magnetic markers 10 are arranged at intervals of 2 m in the middle section excluding the ends connected to the curved section 100C. On the other hand, at the ends of the straight sections 100S connected to the curved section 100C, the intervals between the magnetic markers 10 are narrower than those in the middle section. The interval between the magnetic markers 10 at the ends of the straight sections 100S is 50 cm. At the connection point 100P between the straight section 100S and the curved section 100C, magnetic markers 10 are arranged so that the vehicle 2 can identify the connection point 100P while in motion. The interval between the magnetic markers 10 at the ends of the straight sections 100S means the interval between the magnetic markers 10 arranged at the connection point 100P and the magnetic markers 10 of the adjacent straight section 100S.

[0026] Note that it is also possible to change the interval between the magnetic markers 10 at the ends of the straight section 100S according to the degree of curvature of the connected curved section 100C. For example, the greater the curvature of the connected curved section 100C (the smaller the radius of curvature), that is, the sharper the curve, the narrower the interval between the magnetic markers 10 at the ends of the straight section 100S may be set.

[0027] Also, it is possible to make the intervals between the magnetic markers 10 at the ends of the straight section 100S different between the connection point 100P located at the entrance to the curved section 100C and the connection point 100P located at the exit from the curved section 100C among the connection points 100P between the straight section 100S and the curved section 100C.

[0028] In this example, as the location where the interval between the magnetic markers 10 is narrower than that in the middle section of the straight section 100S, one interval formed by two adjacent magnetic markers 10 is illustrated. Instead of this, it is also possible to provide at the ends of the straight section 100S two or more intervals formed by three or more consecutive magnetic markers 10. It is also possible to gradually narrow the interval between adjacent magnetic markers 10 as it gets closer to the connection point 100P.

[0029] Furthermore, at the end of the straight path 100S, for example, it is also possible to arrange six magnetic markers 10 at narrow intervals (Fig. 6). This figure shows an example of a six - connected marker in which six magnetic markers 10 are arranged at an arrangement pitch of 10 cm. If the interval between adjacent magnetic markers 10 becomes too narrow, there is a risk that it will be difficult to distinguish each magnetic marker 10 among adjacent magnetic markers 10 on the vehicle 2 side. For example, when the N - pole magnetic marker 10N and the N - pole magnetic marker 10N are close to each other, the peaks indicating the magnetic distribution by each magnetic marker 10 tend to merge. Here, the N - pole magnetic marker 10N means a magnetic marker 10 whose magnetic polarity detected on the vehicle 2 side is the N - pole.

[0030] Therefore, when narrowing the interval (arrangement pitch) between adjacent magnetic markers 10, as shown in Fig. 6, it is advisable to alternately lay the N - pole magnetic marker 10N and the S - pole magnetic marker 10S. The N - pole magnetic marker 10N and the S - pole magnetic marker 10S have opposite magnetic action directions and different positive and negative magnetic distribution peaks. For any combination of positive and negative magnetic distribution peaks, even when the interval between the N - pole magnetic marker 10N and the S - pole magnetic marker 10S is narrow, it is relatively easy to detect the positive and negative peaks.

[0031] (3) Surveying process The surveying process P3 (Fig. 3) is a process of surveying the laying positions of the respective magnetic markers 10. The surveying process is an example of a laying position acquisition step for acquiring the laying positions of the magnetic markers 10 laid on the runway 100. For the road surface on which the runway 100 is provided, two - dimensional coordinates (Fig. 7) are virtually set. In the surveying process, the coordinates of the laying positions of the magnetic markers 10 in these two - dimensional coordinates are acquired.

[0032] The two - dimensional coordinates (Fig. 7) are defined by a reference origin O and coordinate axes x and y that are orthogonal to this origin. The laying position of the magnetic marker 10 measured in the surveying process P3 is a position specified by the x - coordinate and the y - coordinate on this two - dimensional coordinate. In the surveying process P3, the laying positions of all the magnetic markers 10 on the runway 100 are specified.

[0033] The laying positions of the respective magnetic markers 10 are stored in a computer device (not shown) that executes (4) the plotting step P4 (FIG. 3) and (5) the target trajectory generation step P5 (FIG. 3). The computer device is an example of a processing circuit having an arithmetic processing function. The computer device includes a storage device for storing data, and an electronic board on which a CPU (Central Processing Unit) or the like for executing arithmetic processing is mounted. A program for generating the target trajectory 1T is installed in the computer device. The storage device stores map data representing the above two-dimensional coordinates. The map data includes data representing the shape and position of the track 100.

[0034] (4) Plotting step The plotting step P4 (FIG. 3) is a step of plotting the marker position 10P representing the laying position of each magnetic marker 10 on the map represented by the above map data. This plotting step P4 constitutes an example of a plotting step of plotting the laying position of the magnetic marker 10 as the marker position 10P on the map as shown in FIG. 8.

[0035] The computer device plots the laying positions of the respective magnetic markers 10 stored in the above (3) surveying step P3 (FIG. 3) on the map as the marker positions 10P. The computer device can display the marker positions 10P together with the track 100 on the map, for example, like the display screen (main window 5M) of FIG. 8. Note that each marker position 10P on the map is assigned a sequence. The route order connecting the marker positions 10P according to the sequence represents the route along which the vehicle 2 travels.

[0036] On the display screen by the computer device, as shown in FIG. 8, in addition to the main window 5M for displaying the map, a toolbox 5T for performing various operations is displayed. In the toolbox 5T, for example, a pointing button 51, a vehicle specification input button 52, an execution button 53, etc. are arranged. Note that the contents of each button will be described later.

[0037] (5) Target trajectory generation step The target trajectory generation step P5 (Fig. 3) is a step executed by a computer device that stores the above map data. The target trajectory generation step P5 constitutes an example of a target trajectory calculation step of obtaining a curve passing through the marker position 10P as the target trajectory 1T on a map on which the marker position 10P is plotted.

[0038] In the target trajectory generation step P5 of this example, a cubic spline curve passing through each marker position 10P on the map is generated as the target trajectory 1T. Here, the cubic spline curve is a curve that smoothly connects points arranged two-dimensionally. In the cubic spline curve, adjacent points are connected by a curve of a cubic function so that the connection of the curve at each point (marker position 10P) becomes smooth. Note that the curve is not limited to the cubic spline curve. In addition to the cubic spline curve, a Lagrange curve, an Hermite curve, etc. can also be adopted.

[0039] The target trajectory generation step P5 can be executed in a state where the marker position 10P is plotted on the map as shown in Fig. 8. When the execution button 53 of the toolbox 5T is selected using a mouse or the like, the target trajectory 1T can be generated by arithmetic processing by the computer device (Fig. 9). The target trajectory 1T is a cubic spline curve passing through each marker position 10P in order.

[0040] (6) Target trajectory correction step The target trajectory correction step is a step of correcting the target trajectory 1T. The target trajectory correction step is useful, for example, when eliminating defects when actually driving the vehicle 2 along the target trajectory 1T or optimizing the driving trajectory of the vehicle 2. For example, when the overhang of the vehicle 2 causes an excessive overhang amount to the outside of the curve or when the vehicle 2 leans too much toward the inside of the curve due to the inner wheel difference, etc., it is advisable to adjust the target trajectory 1T on the map represented by the map data. For example, it is also possible to select a point on the cubic spline curve forming the target trajectory 1T by, for example, a mouse operation (not shown) and correct the target trajectory 1T by deforming the cubic spline curve.

[0041] Furthermore, in the main window 5M displayed by the computer device, it is also possible to adjust the position of any marker position 10P (FIG. 10). The marker position 10P for which the position is to be adjusted can be selected by the cursor 5C displayed according to the selection of the pointing button 51. By changing the position of the selected marker position 10P by a mouse operation or the like, the position of the marker position 10P can be changed. After adjusting the position of the marker position 10P, it is advisable to recalculate the cubic spline curve.

[0042] Also, for example, on the map, a new marker position 10P that does not correspond to the actually laid magnetic marker 10 may be added, and the cubic spline curve may be recalculated. Furthermore, after changing the laying position of the actual magnetic marker 10 on the runway 100, the surveying process P3 (FIG. 3), the plotting process P4 (FIG. 3), and the target trajectory generation process P5 (FIG. 3) may be performed again to create a new target trajectory 1T.

[0043] As described above, this example is an example of a method for setting the target trajectory 1T when the vehicle 2 travels along the runway 100 composed of the straight runway 100S and the curved runway 100C. This setting method is a method including the scribing process P1, the construction process P2, the surveying process P3, the plotting process P4, and the target trajectory generation process P5.

[0044] In the method for setting the target trajectory 1T of this example, on the map where the laying position of the magnetic marker 10 is plotted as the marker position 10P, a curve passing through the marker position 10P is obtained as the target trajectory 1T. And in the above plotting process P4, the marker positions 10P are plotted so that the interval between the marker positions 10P at the end of the straight runway 100S adjacent to the curved runway 100C is narrower than that in the middle part of the straight runway 100S.

[0045] At the end of the straight path 100S, the target trajectory 1T tends to protrude to the outer peripheral side of the adjacent curved path 100C. If the marker positions 10P are plotted at narrow intervals at the end of the straight path 100S, the tendency for the target trajectory 1T to protrude outside the curve can be suppressed. In the middle part of the straight path 100S, since the interval between the marker positions 10P can be widened, the number of magnetic markers 10 laid can be reduced, and the cost can be suppressed. According to the method for setting the target trajectory 1T in this example, the target trajectory for causing the vehicle 2 to travel with high accuracy can be set efficiently.

[0046] In the scribing process P1 of this example, when the vehicle 2 travels on the road 100 by manual driving by the driver, the trajectory is obtained as a planned line (travel line 2L) for laying the magnetic markers 10. Instead of manual driving by the driver, it is also possible to obtain the trajectory when the vehicle 2 travels by automatic driving as the planned line.

[0047] In this example, regardless of the curvature of the curved path 100C adjacent to the end of the straight path 100S, the interval between the marker positions 10P at the end of the straight path 100S is made constant. Instead of this, the larger the curvature of the adjacent curved path 100C (the smaller the radius of curvature), that is, the sharper the curve of the curved path 100C, the better it is to narrow the interval between the marker positions 10P at the end of the straight path 100S. This is because the sharper the curve of the curved path 100C, the stronger the tendency for the target trajectory 1T to protrude outside the curve. If the interval between the marker positions 10P is narrowed at the end of the straight path 100S, the degree of suppression of the protrusion of the target trajectory 1T to the outside of the curve can be increased.

[0048] (Example 2) This example is an example in which the contents of the magnetic marker construction process P2 and the plotting process P4 are changed based on Example 1. This content will be described with reference to FIGS. 3, 11, and 12. In the construction process P2 (Figure 3) of this example, as illustrated in Figure 11, the magnetic markers 10 are arranged at substantially constant intervals regardless of whether it is at the end of the straight path 100S or in the middle of the straight path 100S. In the construction process P2 of this example, the magnetic markers 10 are not laid at narrow intervals at the end of the straight path 100S. Note that the angular interval of the magnetic markers 10 on the curved path 100C is 45 degrees, the same as in the first embodiment.

[0049] In the plotting process P4 of this example, in addition to the first plotting process of plotting the actual laying positions of the magnetic markers 10 as marker positions 10P, a second plotting process of plotting the laying positions of virtual magnetic markers as marker positions 10P is executed. The plotting process P4 of this example is executed by the exemplified computer device, the same as in the first embodiment.

[0050] The first plotting process is the same process as the process executed in the plotting process of the first embodiment. In the first plotting process, the laying positions of the respective magnetic markers 10 specified by the surveying process P3, the same as in the first embodiment, are plotted on the map. Figure 12 is an illustration of the main window 5M in which the marker positions 10P are displayed. In the figure, the white circles represent the marker positions 10P plotted by the first plotting process.

[0051] The second plotting process is a process of additionally plotting on the map, as the marker position 10P, the position selected on the main window 5M (Figure 12) displayed by the computer device. In the illustration of Figure 12, the marker positions 10P added by the second plotting process are indicated by filled circles. To perform the operation of adding the marker position 10P, for example, it is necessary to select the pointing button 51 and switch to a mode in which the position can be specified. In this mode, the marker position 10P can be added by moving the cursor 5C to the desired position and specifying the position. This marker position 10P indicates the laying position of the virtual magnetic marker on the track 100.

[0052] According to the combination of the first and second plotting processes, for example, even if the actual number of magnetic markers laid is less than that in the first embodiment, it is possible to realize the arrangement of the marker positions 10P similar to that in the first embodiment.

[0053] In addition, for example, in the curved road 100C, the interval between the marker positions 10P can also be adjusted. For example, while changing the position on the map of the marker position 10P corresponding to the actual magnetic marker 10, for example, by a mouse operation, if a marker position 10P corresponding to a virtual magnetic marker is added, the interval between the marker positions 10P can be changed. Regarding other configurations and functions and effects, they are the same as those in the first embodiment.

[0054] (Embodiment 3) This example is based on the first embodiment, and the kerf process P1 in the same example is replaced with a marker line generation process. This content will be described with reference to FIGS. 3, 13 to 15.

[0055] The marker line generation process in this example is a process in which a computer device generates a marker line 20L (FIG. 15). This marker line generation process forms an example of a planned line acquisition step for acquiring a marker line 20L which is an example of a planned line. The marker line 20L is a line indicating the laying position when the magnetic marker 10 is constructed in the subsequent construction process P2. The marker line 20L replaces the traveling line 2L in the first embodiment. The marker line 20L is generated by an operator operation on the main window 5M (see FIG. 13) displayed by the computer device.

[0056] In the main window 5M of FIG. 13, a map based on the map data stored in the computer device is displayed, and a toolbox 5T is also displayed. The road 100 is displayed on the map. In the toolbox 5T, there are arranged pointing buttons 51 for designating points such as a start point, a goal point, and a passing point, a vehicle specification input button 52 for inputting the specifications of the vehicle, an execution button 53, and the like.

[0057] When the pointing button 51 is selected, a point on the track 100 can be specified using a pointing device such as a mouse. When specifying a point on the track 100, it is necessary to pre-select a point type representing the attribute of the point. When the pointing button 51 is selected, a pull-down menu for selecting the point type is displayed. In the pull-down menu, point types such as start point S (Start), goal point G (Goal), way point W (Way Point) can be selected (Fig. 13).

[0058] For example, on the main window 5M, as shown in Fig. 13, after specifying a plurality of way points W in order, and finally selecting the previously specified way point W again, an annular path 100L similar to that in the first embodiment can be set. For example, after specifying the start point S first, specifying several way points W, and finally specifying the goal point G, a non-annular path (not shown) can be set. The path 100L illustrated in Fig. 13 is an annular route set by arranging a plurality of way points W. The path 100L is a path connecting the center of the track 100.

[0059] When generating the marker line 20L, it is necessary to input the specifications of the vehicle 2. When the vehicle specification input button 52 is selected, a pull-down menu for selecting items of vehicle specifications such as wheelbase, vehicle body length, vehicle width, steering range (the angular range in which the steering wheel can be steered), presence or absence of traction, etc. is displayed (Fig. 14). If any item of vehicle specifications is selected, an input field (not shown) will be pop-up displayed, and the vehicle specifications can be input, for example, by numerical input etc.

[0060] After setting the path 100L as described above and inputting the specifications of the vehicle 2 to be run, if the execute button 53 is selected, a marker line 20L for laying the magnetic marker 10 can be generated based on the path 100L. The path 100L (Fig. 13) set on the main window 5M and the marker line 20L generated based on this path 100L are illustrated in Fig. 15.

[0061] The path 100L illustrated in FIG. 15 is a path that connects the center of the runway 100 as described above. On the other hand, the marker line 20L generated by the computer device is a line representing the laying position of the magnetic marker 10 that can be detected by the vehicle 2 with high certainty, and reflects the vehicle specifications.

[0062] The marker line 20L illustrated in FIG. 15 is a line on the map represented by the map data. In order to actually lay the magnetic marker 10 on this marker line 20L, it is necessary to associate the marker line 20L generated by the computer device with the actual runway 100. As such a method of association, for example, there is a method of marking the marker line 20L on the actual runway 100. By marking the runway in this way, the magnetic marker 10 can be installed (laid) in the same manner as in the first embodiment.

[0063] Alternatively, it is also possible to specify the position where the magnetic marker 10 is to be laid on the marker line 20L displayed by the computer device by a mouse operation. It is preferable to mark the position on the map output by the computer device according to the specification on the actual runway 100 as the laying position for laying the magnetic marker 10. If the laying position is marked, the magnetic marker 10 can be installed with high positional accuracy. Note that the other configurations and effects are the same as those in the first embodiment.

[0064] (Reference Example) The reference example is an example in which the technical effect of an arrangement mode in which the interval between the marker positions 10P is narrowed at the end of the straight runway 100S is verified. This content will be described with reference to FIGS. 16 to 20. FIGS. 16 and 17 are illustrations of the trajectory 101 generated in the runway 100 including a right-angled corner. In these figures, the ideal trajectory 103 is illustrated by a dashed line. The runway 100 is a runway in which two straight runways 100S whose longitudinal directions are orthogonal to each other are connected by a curved runway 100C with a curvature radius of 1.5 m. The method of generating the trajectory 101 is the same as the target trajectory generation process (P5 in FIG. 3) of the first embodiment. Note that the arrangement interval of the marker positions 10P in the curved runway 100C is the same 45 degrees as in the first embodiment.

[0065] FIG. 16 illustrates an example of the arrangement mode of the present invention in which marker positions 10P are arranged at narrow intervals at the ends of a straight path 100S adjacent to a curved path 100C. In order to manifest the effect of the arrangement mode of the present invention, marker positions 10P are arranged only at both ends of the straight path 100S, and marker positions 10P in the middle part are omitted. In the case of FIG. 16, the deviation between the generated locus 101 (illustrated by a solid line) and the ideal locus 103 (illustrated by a broken line) is small. On the other hand, FIG. 17 illustrates an example of a mode in which only one marker position 10P is arranged at the end of a straight path 100S adjacent to a curved path 100C. In the case of this figure, the deviation between the generated locus 101 and the ideal locus 103 is large in the middle part of each straight path 100S.

[0066] Furthermore, in this example, the effect of the arrangement mode of the present invention when the marker positions 10P of the curved path 100C are omitted is also examined. FIGS. 18 and 19 are the same as the configuration of FIG. 16 or FIG. 17 except that the marker positions 10P of the curved path 100C are omitted. In the case of FIG. 18 in which the marker positions 10P are arranged in the arrangement mode of the present invention at the ends of the straight path 100S, even if the marker positions 10P of the curved path 100C are omitted, a locus 101 close to the ideal locus 103 is calculated. On the other hand, in the case of FIG. 19 in which there is only one marker position 10P at the end of the straight path 100S, the deviation between the calculated locus 101 and the ideal locus 103 is excessive.

[0067] Furthermore, in this example, as in FIG. 6 referred to in Example 1, the effect of a mode in which, for example, six magnetic markers 10 (six-connected markers) are arranged at narrow intervals at the ends of the straight path 100S is examined. In the case of FIG. 20, six magnetic markers are arranged at narrow intervals (arrangement pitch 10 cm) at the ends of the straight path 100S. In this case, compared with FIG. 18, the deviation between the generated locus 101 and the ideal locus 103 is further suppressed.

[0068] As described above, specific examples of the present invention have been described in detail as in the embodiments. However, these specific examples merely disclose an example of the technology included in the claims. Needless to say, the claims should not be construed in a limited manner by the configuration, numerical values, etc. of the specific examples. The claims include technologies obtained by variously modifying, changing, or appropriately combining the specific examples using known technologies and the knowledge of those skilled in the art.

Explanation of Signs

[0069] 1 Vehicle system 1T Target trajectory 10 Magnetic marker 10N North pole magnetic marker 10S South pole magnetic marker 10P Marker position 100 Track 100C Curved track 100S Straight track 100L Route 100P Connection point 2 Vehicle 2L Travel line (planned line) 20L Marker line (planned line) 25 Dropping device 3 Magnetic sensor module 5M Main window 5T Toolbox

Claims

1. A method for setting a target trajectory for controlling a vehicle to travel along a running track composed of a straight track and a curved track, comprising: a planned line acquisition step of acquiring a planned line for laying magnetic markers on the running track so that the vehicle running on the track can be detected; a laying step of laying magnetic markers at intervals along the planned line; a laid position acquisition step of acquiring the laid positions of the magnetic markers laid on the running track; a plotting step of plotting the laid positions of the magnetic markers on a map as marker positions; a target trajectory calculation step of obtaining, on the map on which the marker positions are plotted, a curve passing through the marker positions as the target trajectory; The method for setting a target trajectory according to claim 1, wherein, in the plotting step, the marker positions are plotted such that the interval between the marker positions at the end of the straight track adjacent to the curved track is narrower than that at the middle of the straight track.

2. The method for setting a target trajectory according to claim 1, wherein the planned line acquisition step is a step of acquiring, as the planned line, the trajectory when the vehicle travels on the running track by a manual operation by a driver.

3. The method for setting a target trajectory according to claim 1, wherein, in the laying step, at the end of the straight track, the magnetic markers are laid at an interval narrower than that at the middle of the straight track.

4. The method for setting a target trajectory according to claim 1, wherein, in the plotting step, in addition to the laid positions acquired in the laid position acquisition step, the laid positions of virtual magnetic markers are plotted on the map as the marker positions such that the interval between the marker positions at the end of the straight track is narrower than that at the middle of the straight track.

5. The method for setting a target trajectory according to claim 1, wherein the greater the curvature of the adjacent curved tracks, the narrower the interval between the marker positions at the end of the straight track on the map.

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