Method and system for simulating travel of articulated vehicle

Abstract

To provide a simulation method for efficiently predicting trajectories of a towing vehicle and a bogie that constitute an articulated vehicle.SOLUTION: A method for simulating travel of an articulated vehicle 2 that has a towing vehicle 21 at the forefront, continued in series with two bogies 22A and 22B and having front wheels being steering wheels and fixed-steered rear wheels, executes the processing of: setting, as a route, a travel plan line 10L along which a rear axle center RC which is a midpoint of an axle of a rear wheel of the towing vehicle 21, is aligned; determining a trajectory of a front axle center FC of the towing vehicle 21 when the towing vehicle 21 is made to travel so that the rear axle center RC is aligned with the travel plan line 10L; and determining a trajectory of each of the bogies 22A and 22B based on the trajectory of the front axle center FC.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a simulation of the travel trajectory of an articulated vehicle. [Background technology]

[0002] Conventionally, articulated vehicles in which a towing vehicle pulls a dolly have been used to improve the efficiency of transporting products and parts (see, for example, Patent Document 1). Articulated vehicles can simultaneously transport large amounts of products and parts that cannot be carried by a single vehicle. When operating articulated vehicles, it is necessary to set the trajectory of the towing vehicle so that each dolly coupled to the towing vehicle does not go out of the aisle.

[0003] The following Patent Document 1 describes a system for searching for the most efficient route for a vehicle when there are multiple routes from a start point to a goal point. This system attempts to search for the optimal route by comparing the costs of multiple routes.

[0004] In the system of Patent Document 1, the locus of the towing vehicle when traveling alone and when towing are determined in advance for each section constituting the route. A cost is set for each of the locus of traveling alone and the locus of towing in each section. In this system, a cost is selected and accumulated for each section constituting the route according to whether the vehicle is traveling alone or when towing, and the cost for each route is calculated as the route cost. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] JP 2022-114188 A Summary of the Invention [Problem to be solved by the invention]

[0006] However, the conventional articulated vehicles have the following problems: While it is relatively easy to determine the trajectory of a towing vehicle alone, in the case of an articulated vehicle in which a bogie is coupled to a towing vehicle, unique circumstances arise in which the traveling trajectories of the towing vehicle and the bogie are different, and this poses technical problems in how to determine the towing travel trajectory in each section and how to determine the towing travel trajectory efficiently.

[0007] The present invention has been made in consideration of the above-mentioned problems in the conventional art, and has an object to provide a simulation method and system for efficiently predicting the trajectories of the towing vehicle and the bogie that make up an articulated vehicle. [Means for solving the problem]

[0008] One aspect of the present invention is a method for simulating the running of a combination vehicle in which one or more bogies are connected in series, with a towing vehicle having steered front wheels and fixed-steered rear wheels at the front, comprising the steps of: A process of setting a travel plan line along which a rear axle center RC, which is the midpoint of the axle of the rear wheels of the towing vehicle, is aligned; A process of determining a path of a front axle center FC, which is the midpoint of the axle of the front wheels of the towing vehicle, and a direction of the towing vehicle when the towing vehicle is driven so that the rear axle center RC is aligned with the driving plan line; and determining the trajectory and orientation of the one or more bogies based on the trajectory of the front axle center FC and the orientation of the towing vehicle.

[0009] One aspect of the present invention is a system for simulating the running of a combination vehicle in which one or more bogies are connected in series, with a towing vehicle having steered front wheels and fixed-steered rear wheels at the front, the system comprising: a processing unit that sets a driving plan line for aligning a rear axle center RC, which is a midpoint of the axle of the rear wheels of the towing vehicle, with respect to a route along which the combination vehicle is to be moved; a processing unit that calculates a path of a front axle center FC, which is the midpoint of a front wheel axis of the towing vehicle, and a direction of the towing vehicle when the towing vehicle is driven so that the rear axle center RC is aligned with the driving plan line; and a processing unit that determines the trajectory and orientation of the one or more bogies based on the trajectory of the front axle center FC and the orientation of the towing vehicle. Effect of the Invention

[0010] In the present invention, when simulating the traveling of an articulated vehicle, first, a traveling plan line is set along which the rear axle center RC should be aligned. In the present invention, the trajectory of the front axle center FC is obtained based on the traveling plan line, and further, the trajectories of one or more bogies are obtained.

[0011] The driving plan line is a line that can be the trajectory of the rear axle center RC. By using the driving plan line that forms the trajectory of the rear axle center RC as a reference, it is possible to efficiently determine the trajectory of the front axle center FC that is suitable as a control target when steering the towing vehicle. In addition, the rear axle center RC is located close to the fulcrum when towing the bogie. By using the driving plan line that forms the trajectory of the rear axle center RC as a reference, it is possible to efficiently determine the trajectory of the bogie.

[0012] As described above, according to the articulated vehicle running simulation method and system of the present invention, the trajectory of the articulated vehicle can be efficiently determined by setting a running plan line along which the rear axle centre RC should follow. [Brief description of the drawings]

[0013] [Figure 1] FIG. 1 is an explanatory diagram showing an overview of a driving simulation system. [Diagram 2] FIG. [Diagram 3] FIG. 2 is a system diagram showing the configuration of an articulated vehicle. [Figure 4] FIG. [Diagram 5] FIG. 4 is a front view of a display screen for inputting a driving plan line. [Figure 6] FIG. 4 is an explanatory diagram illustrating a driving plan line (driving plan line coordinates) set on a route. [Figure 7]FIG. 4 is an explanatory diagram showing the flow of a running simulation. [Figure 8] FIG. 4 is an explanatory diagram illustrating the trajectory of a front axle center FC. [Figure 9] FIG. 2 is an explanatory diagram illustrating an articulated vehicle that travels such that the rear axle center RC is aligned along a travel plan line. [Figure 10] FIG. 4 is an explanatory diagram illustrating an example of a passing area of ​​an articulated vehicle. [Figure 11] FIG. 11 is an explanatory diagram illustrating a non-recommended area where it is not recommended for articulated vehicles to pass through; [Figure 12] FIG. 4 is an explanatory diagram illustrating a passing area of ​​a magnetic sensor module. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0014] The embodiment of the present invention will be specifically described using the following examples. Example 1 This example relates to a traveling simulation method and traveling simulation system 1S for an articulated vehicle 2 in which a front-wheel-steered towing vehicle 21 tows bogies 22A and B. The contents of this example will be described with reference to Figs.

[0015] The driving environment of the articulated vehicle 2 may be, for example, an indoor environment such as a factory or a logistics warehouse, or an outdoor environment within the premises of a factory or the like. In the driving environment, as shown in Fig. 1, a route 10 is formed by an aisle 12 along which the articulated vehicle 2 can travel. In the explanation of this example, the aisle 12 refers to an area in which the vehicle can travel. On the other hand, the route 10 is a path along which the articulated vehicle 2 travels, and is a concept that does not have a width, area, etc.

[0016] Route 10 (Fig. 1) is a route formed by passage 12 that is roughly C-shaped with the left and right reversed. Passage 12 is an area of ​​a fixed width of 4m. Passage 12 is surrounded by a prohibited area 13 where vehicles are prohibited from entering or exiting. Of the roughly C-shaped passage 12, which is made up of three sides excluding the left side (short vertical side) of the four sides of a horizontally long rectangle, passage 12A corresponding to the upper horizontal side and passage 12C corresponding to the lower side are 20m long, and passage 12B corresponding to the right vertical side is 10m long.

[0017] The route 10 starts from a start point ST located in the upper passage 12A, passes through a passage 12B on the right side, and reaches a goal point GL located in a passage 12C on the lower side. The start point ST and goal point GL indicate the positions of the towing vehicle 21 at the start and the finish. Due to the overall length of the articulated vehicle 2, there is a positional deviation between the start point ST and the goal point GL in the longitudinal direction of the passages 12A and C. The start point ST is located midway along the upper passage 12A, while the goal point GL is located near the end of the lower passage 12C.

[0018] On the actual route 10, individual magnetic markers (not shown) for guiding the travel of the articulated vehicles 2 are placed at intervals. The simulation results of the travel trajectory of the articulated vehicles 2 provide useful information when planning the placement positions of the magnetic markers on the route 10. This is because the magnetic markers need to be placed so that the magnetic sensor module (described later) attached to the towing vehicle 21 passes directly overhead.

[0019] As shown in Fig. 2, the articulated vehicle 2 is made up of a leading towing vehicle 21 equipped with drive wheels and two bogies 22 (bogies 22A and B). In the articulated vehicle 2, the two bogies 22A and B are connected in series to the towing vehicle 21. The towing vehicle 21 is 2 m long and 1 m wide, and the bogies 22A and B are 1.8 m long and 1 m wide. The overall length of the articulated vehicle 2 is approximately 6 m.

[0020] The towing vehicle 21 has a pair of left and right front wheels 211 that are steered wheels, and rear wheels 212 that are driven wheels. The maximum steering angle of the front wheels 211 is 60 degrees. The rear wheels 212 are fixed-rudder wheels in which the axial direction of the rotation shaft is fixed. A connecting hook 219 is provided at the rear of the towing vehicle 21, extending rearward. In addition, a magnetic sensor module 3 for detecting magnetic markers is attached to the rearmost end of the towing vehicle 21. The towing vehicle 21 that tows the dolly 22 tends to need to make large turns when going around corners, for example. The rearmost end of the towing vehicle 21 is less affected by the large turns of the towing vehicle 21, and is therefore an appropriate mounting position for the magnetic sensor module 3.

[0021] The magnetic sensor module 3 is a rod-shaped sensor unit incorporating multiple magnetic sensors (not shown) spaced apart. The magnetic sensor module 3 is attached to the towing vehicle 21 with its longitudinal direction aligned with the vehicle width direction. The length of the rod-shaped magnetic sensor module 3 is close to the vehicle width of the towing vehicle 21. The rod-shaped magnetic sensor module 3 extending along the vehicle width direction can reliably detect the magnetic marker regardless of positional deviation of the towing vehicle 21 in the vehicle width direction relative to the magnetic marker.

[0022] The bogie 22 (22A / B) is a four-wheel vehicle equipped with front wheels 221 which are swivel wheels and rear wheels 222 with fixed steering. The bogie 22 has a connecting bar 220 for connecting to the towing vehicle 21 or the preceding bogie 22, and also has a connecting hook 229 for connecting to the following bogie 22. The connecting bar 220 and the connecting hook 229 extend along the fore-and-aft direction of the vehicle. The connecting hook 229 has the same specifications as the connecting hook 219 of the towing vehicle 21.

[0023] The connecting bar 220 has holes (not shown) for engaging the connecting hooks 219, 229. The connecting hook 219 of the towing vehicle 21 and the connecting bar 220 of the front bogie 22A combine to form a connecting portion 28A. Moreover, the connecting hook 229 of the front bogie 22A and the connecting bar 220 of the rear bogie 22B combine to form a connecting portion 28B.

[0024] A traction shaft 280, which is a virtual vertical axis, is formed at the connecting portions 28A and 28B. The traction shaft 280 is the axis about which the direction of the rear vehicle rotates relative to the direction (orientation) of the front vehicle. The maximum value of the bending angle (traction bending angle), which is the angular deviation between the direction of the front vehicle and the direction of the rear vehicle, is 45 degrees. The traction shaft 280 is located in the gap between the front vehicle and the rear vehicle. The distance (traction shaft distance) between the traction shaft 280 and the axle of the rear wheels (rear axle 222A) of the towed vehicles, the bogies 22A and 22B, is 1.3 m.

[0025] For reference, the system configuration of the towing vehicle 21 will now be described. As shown in Fig. 3, the towing vehicle 21 is configured to include a magnetic sensor module 3, a control unit 40 that controls the traveling of the combination vehicle 2, an IMU (Inertial Measurement Unit) 42 for implementing inertial navigation, a motor unit 44 that drives and rotates the rear wheels 212, a steering unit 46 that steers the front wheels 211, which are steered wheels, and the like.

[0026] The control unit 40 is a unit that controls the traveling of the towing vehicle 21. The control unit 40 controls the steering angle of the front wheels 211 and the rotational angular velocity of the rear wheels 212 via a steering unit 46 and a motor unit 44. The control unit 40 includes an electronic circuit (not shown) that includes a CPU (Central Processing Unit) that executes various calculations, as well as memory elements such as a ROM (Read Only Memory) and a RAM (Random Access Memory).

[0027] In addition to the magnetic sensor module 3, the steering unit 46, and the motor unit 44, the control unit 40 is connected to a memory device constituting a map database 48 and a wheel speed unit 442 that outputs pulses in response to the rotation of the rear wheels 212. The control unit 40 uses the pulses output by the wheel speed unit 442 to identify the vehicle speed.

[0028] The map database 48 is a database that stores driving map data that represents the shapes of the passages 12 and the route 10. Magnetic markers placed on the route 10 are linked to a map represented by the driving map data. By referring to the driving map data, the positions of the magnetic markers can be identified. The driving map data can be assigned the trajectory of a target when the articulated vehicle 2 travels. By referring to the driving map data, the trajectory of the target can be read out.

[0029] The target trajectory is, for example, the trajectory of the front axle center FC, which is the center of the axle of the front wheels 211 of the towing vehicle 21. When the articulated vehicle 2 moves along the route 10, the magnetic sensor module 3 detects a magnetic marker, and further, a lateral deviation from the detected magnetic marker (amount of lateral deviation of the towing vehicle 21) is identified. The lateral deviation from the magnetic marker is converted into a lateral deviation of the front axle center FC from the target trajectory, taking into account the orientation of the towing vehicle 21. The lateral deviation of the front axle center FC from the target trajectory can be subject to steering control of the towing vehicle 21. For example, travel control including steering control that suppresses the lateral deviation of the front axle center FC is applied to the towing vehicle 21, thereby enabling the articulated vehicle 2 to move along the route 10.

[0030] Next, a description will be given of a simulation device 1 (FIG. 1) which is a computer device constituting the driving simulation system 1S of this embodiment and which executes the driving simulation method of this embodiment. The simulation device 1 is a device including a main body 153 having a calculation function, output devices such as a liquid crystal display 151 and a printer, and input devices such as a keyboard 155 and a mouse. The main body 153 contains an electronic board on which an electronic circuit using a CPU is formed, storage devices such as a solid state drive and a hard disk drive, and the like.

[0031] An application program for inputting the driving plan line 10L is installed in the simulation device 1. The driving plan line 10L is a line that forms a trajectory that passes through a rear axle center RC that is the center of the rear axle of the towing vehicle 21 when the articulated vehicle 2 moves along the route 10 from the start point ST to the goal point GL. This application program provides a user interface for inputting the driving plan line 10L on a display screen such as a liquid crystal display 151. An operator can input the driving plan line 10L by graphically operating on the display screen. The contents of the graphical operation will be described later with reference to FIG. 5.

[0032] The main body 153 is provided with a communication port such as a LAN (Local Area Network) port and a USB port, and various data can be input and output via these ports. Data acquired by the main body 153 from the outside include, for example, map data and vehicle specifications. The map data is data that represents two-dimensional coordinates of the route 10, passage 12, and prohibited area 13 illustrated in Fig. 1. The map data acquired by the simulation device 1 may be shared with the above-mentioned driving map data stored in the map database 48 (see Fig. 3), or may be data of different specifications.

[0033] The data output by the main body 153 to the outside include data showing the trajectory of the articulated vehicle 2 when it moves along the route 10, the determination result of whether it is possible to drive, etc. The determination result of whether it is possible to drive is a determination result of whether or not the articulated vehicle 2 can drive along the passage 12 based on the input driving plan line 10L. The output form of the determination result may be, for example, a display on the display screen of the liquid crystal display 151, or may be a printout by a printer or the like.

[0034] The simulation device 1 can realize the functions of the following units by the CPU executing software programs. (1) Travel plan line setting unit: a processing unit that sets the coordinates (travel plan line coordinates) of the travel plan line 10L inputted, for example, by an operator using an application program, to the route 10. The travel plan line setting unit sets the travel plan line to the route 10 by associating the travel plan line coordinates with map data. (2) Towing vehicle trajectory estimation unit: a processing unit that determines the trajectory of the front axle center FC, which is the midpoint of the axis of the front wheels 211 of the towing vehicle 21, and the orientation (posture) of the towing vehicle 21. The towing vehicle trajectory estimation unit determines the trajectory of the front axle center FC and the orientation of the towing vehicle 21 as the rear axle center RC moves along the driving plan line 10L. (3) Bogie orientation estimation unit: A processing unit that estimates the orientation of the bogies 22A and B. The bogie orientation estimation unit determines the orientation of the bogie 22 that is directly towed by the towing vehicle 21 or the bogie 22, based on the orientation of the towing vehicle 21 or the bogie 22 that is at the front of the articulated vehicles 2 in the traveling direction. (4) Bogie trajectory estimation unit: a processing unit that determines the trajectories of the bogies 22A and 22B that constitute the articulated vehicle 2. (5) Travel feasibility determination unit: A processing unit that determines whether or not the articulated vehicle 2 is capable of traveling along the passage 12. The travel feasibility determination unit determines the passing areas through which each vehicle will pass when the articulated vehicle 2 moves along the route 10, based on the trajectory and orientation of the towing vehicle 21 determined by the towing vehicle trajectory estimation unit and the trajectories and orientations of the bogies 22A and 22B determined by the bogie trajectory estimation unit. Then, the travel feasibility determination unit determines whether or not the articulated vehicle 2 can depart from the start point ST and reach the goal point GL, based on the passing areas of each vehicle.

[0035] Next, a description will be given of a traveling simulation method according to this embodiment, which is executed by the traveling simulation system 1S configured as described above. When the traveling simulation method according to this embodiment is executed, the specification data of the towing vehicle 21, the specification data of the bogie 22 which is the towed vehicle, the data of the traveling plan line 10L, the coordinate data of the passage 12, the coordinate data of the prohibited area 13, etc. are input data.

[0036] The specification data of the towing vehicle 21 is, for example, as shown in Table 1. The values ​​exemplified in Table 1 are the values ​​of each dimension in FIG. [Table 1]

[0037] For example, L0 in Table 1 is the distance between the front axle 211A and the rear axle 212A of the towing vehicle 21, i.e., the wheelbase. For example, dimension W0 is the width of the towing vehicle 21. For example, dimension H0 is the distance from the rear axle 212A to the rear towing axle 280. α_max is not a dimension but the maximum steering angle of the front wheel 211, which is the steered wheel. α_rate_max is not a dimension but the maximum steering angular speed.

[0038] The specification data of the dolly 22 is, for example, as shown in Table 2. The values ​​exemplified in Table 2 are the values ​​of each dimension in FIG. [Table 2]

[0039] For example, num in Table 2 is not a dimension but the number of bogies 22 towed by the towing vehicle 21. For example, L1 is the distance from the front towing axle 280 to the rear axle 222A (towing axle distance). For example, H1 is the distance from the rear axle 222A to the rear towing axle 280. For example, β_max is the maximum bending angle of the coupling part 28. The bending angle (towing bending angle) is the angular deviation between the azimuth (direction) of the towing vehicle 21 and the azimuth of the bogie 22A, or the angular deviation between the azimuth of the front bogie 22A and the azimuth of the rear bogie 22B.

[0040] In the traveling simulation method of this example, the trajectories and orientations of the towing vehicle 21 and the bogies 22A and B are calculated based on the traveling plan line 10L input by the operator. Then, the passing area of ​​the articulated vehicle 2 is identified based on the trajectories and orientations of the towing vehicle 21 and the bogies 22A and B. As will be described later with reference to Fig. 7, the traveling simulation method of this example is a method that includes a traveling plan line setting process P1, a towing vehicle trajectory estimation process P2, a bogie trajectory estimation process P3, and a traveling feasibility determination process P4.

[0041] Below, following the explanation of how the operator inputs the travel plan line 10L, the contents of the travel plan line setting process P1, the towing vehicle trajectory estimation process P2, the bogie trajectory estimation process P3, and the travel feasibility determination process P4 will be explained in order.

[0042] (How to enter a driving plan line) As described above, the simulation device 1 can execute an application program for inputting the travel plan line 10L. This application program allows the travel plan line 10L to be input on a display screen such as the liquid crystal display 151. In response to the execution of the application program, as shown in Fig. 5, a main window 15W displaying the route 10 and the passage 12 is displayed, and a toolbox 15T for inputting the travel plan line 10L is also displayed.

[0043] The route 10 and the passage 12 in the main window 15W (FIG. 5) are displayed based on the map data obtained from an external source. The tool box 15T is provided with operation buttons for switching the display mode, such as a zoom-in button and a zoom-out button, and operation buttons for switching the input mode, such as a straight line button, a circular arc button, and a lane change button.

[0044] The straight line button is a button for switching to a mode for inputting a straight line trajectory as the driving plan line 10L. The arc button is a button for switching to a mode for inputting an arc trajectory as the driving plan line 10L. The lane change button is a button for switching to a mode for inputting a lane change trajectory as the driving plan line 10L. Here, the lane change trajectory is a trajectory that changes the position of the course in the width direction without changing the course direction before and after the lane change.

[0045] For example, when the mode is switched to input of a straight line trajectory, a straight line trajectory can be input as the travel plan line 10L by operating a mouse or the like. By setting the start point and the end point with a mouse or the like, the straight line trajectory from the start point to the end point can be input as the travel plan line 10L. Figure 5 shows a state in which the start point ST is set as the start point, and then point P1 is set as the end point, thereby inputting the straight line trajectory from the start point ST to point P1.

[0046] For example, after switching to a mode for inputting a circular arc trajectory as shown in Fig. 5, by setting point P1 as the starting point and point P2 as the ending point, the circular arc trajectory connecting points P1 and P2 can be input. For example, the starting point and the ending point can be set by moving cursor C using an input device such as a mouse and selecting a position on the screen. In this way, the driving plan line 10L can be input by seamlessly connecting the start point ST and the goal point GL by appropriately combining straight line trajectories, circular arc trajectories, and lane change trajectories on the application program.

[0047] By using the application program executed by the simulation device 1 of this embodiment, the driving plan line 10L can be input simply by appropriately combining straight line trajectories, circular arc trajectories, and lane change trajectories (see FIG. 6). By using the application program, it is possible to create a driving plan for the articulated vehicles 2 without any special knowledge or skills.

[0048] (Travel plan line setting process P1) The travel plan line setting process P1 (FIG. 7) is a process for setting the input travel plan line 10L to the route 10. In this travel plan line setting process P1, the travel plan line coordinates, which are the coordinates of the travel plan line 10L, are associated with the map data, so that the travel plan line 10L is set to the route 10. In the travel plan line setting process P1, the travel plan defined by the line called the travel plan line 10L is converted into the travel plan line coordinates, which are discrete coordinates. After the travel plan line setting process P1 is performed, the map data specifies the positional relationship of the travel plan line 10L (travel plan line coordinates) with respect to the route 10 and the passage 12.

[0049] (Tow vehicle trajectory estimation process P2) The towing vehicle trajectory estimation process P2 (FIG. 7) is a process for estimating the trajectory 10F (FIG. 8) of the front axle center FC of the towing vehicle 21 and the orientation of the towing vehicle 21. In this towing vehicle trajectory estimation process P2, the trajectory 10F of the front axle center FC and the orientation of the towing vehicle 21 are estimated when the rear axle center RC is moved so as to pass through discrete driving plan line coordinates. The trajectory 10F of the front axle center FC and the orientation (posture) of the towing vehicle 21 are found based on the specifications of the towing vehicle 21, such as the wheelbase and steering angle range, and the driving plan line coordinates.

[0050] Specifically, the position of the front axle center FC when the rear axle center RC passes through the driving plan line coordinates can be calculated by shifting the position along the direction of the towing vehicle 21 from the driving plan line coordinates by an amount equal to the positional difference between the rear axle center RC and the front axle center FC. When the articulated vehicles 2 travel so that the rear axle center RC is aligned with the driving plan line 10L, the front axle center FC follows a trajectory, for example, as shown in Fig. 9. In the towing vehicle trajectory estimation process P2, in addition to the trajectory 10F and direction (attitude) of the front axle center FC, the steering angle (front wheels) is calculated at each position on the route 10.

[0051] In addition, at the connection between the straight line and the arc on the travel plan line 10L, the trajectory 10F of the front axle center FC may be adjusted so that the change in the steering angle is smooth. At the above-mentioned connection, due to the inner wheel difference of the towing vehicle 21, the front axle center FC passes through a curve on the outer side of the arc that constitutes the travel plan line 10L. When the front axle center FC moving along the straight line that constitutes the travel plan line 10L transfers to a curve on the outer side of the arc that constitutes the travel plan line 10L, or transfers from this curve on the outer side to the straight line that constitutes the travel plan line 10L, it is advisable to adjust the trajectory of the front axle center FC. When the front axle center FC transfers as described above, for example, the change in the steering angle can be made smooth by adjusting the trajectory of the front axle center FC so that it becomes the trajectory of a so-called lane change.

[0052] (Carriage trajectory estimation process P3) The bogie trajectory estimation process P3 is a process for estimating the trajectories and orientations of the bogies 22A and B towed by the towing vehicle 21. In the bogie trajectory estimation process P3, the trajectory 10F of the front axle center FC and the steering angle calculated in the towing vehicle trajectory estimation process P2 are applied to the articulated vehicle model to calculate the trajectories and attitudes (orientations) of the two following bogies 22 in order from the front. The bogie trajectory estimation process P3 is, so to speak, a process for running the bogies 22A and B in a simulation space, which is a virtual space.

[0053] The articulated vehicle model is a model in which the bogie 22, which is the towed vehicle, is towed via the towing axle 280. The articulated vehicle model in this example is a two-wheel model of multiple articulation that calculates the trajectory of each vehicle. In this articulated vehicle model, angles are obtained in the following order: front wheel steering angle (steering angle) of the towing vehicle 21 → yaw angle (direction, attitude) of the towing vehicle 21 → bending angle of the coupling section 28A → yaw angle (direction, attitude) of the bogie 22A → bending angle of the coupling section 22B → yaw angle (direction, attitude) of the bogie 22B, and the trajectory of each vehicle is calculated. In this articulated vehicle model, a relationship is formulated that represents the motion of a multiple articulated vehicle at low speeds where the influence of centrifugal force is small. When formulating the vehicle model, the specifications of the towed vehicle (see Table 2), such as the distance between the towing axle 280 and the rear axle 222A and the bending angle range around the towing axle 280, are reflected.

[0054] The bogie trajectory estimation process P3 is executed in order for the combination of the towing vehicle 21 and the front bogie 22A, and the combination of the front bogie 22A and the rear bogie 22B. For the combination of the towing vehicle 21 and the front bogie 22A, the coordinates of the trajectory 10F of the front axle center FC of the towing vehicle 21 are applied to the articulated vehicle model to determine the trajectory of the towing axle 280 and the orientation of the bogie 22A, which is the towed vehicle.

[0055] For a combination of the front bogie 22A and the rear bogie 22B, the coordinates of the trajectory of the towing axle 280 of the front coupling part 28A of the bogie 22A are applied to the articulated vehicle model to determine the trajectory of the front coupling part 28B of the bogie 22B, which is the towed vehicle, and the orientation of the bogie 22B. Furthermore, in the bogie trajectory estimation process P3, the bend angle (towing bend angle) of the coupling parts 28A and 28B around the towing axle 280 is determined at each position on the route 10.

[0056] (Driving possibility determination process P4) The travel feasibility determination process P4 is a process that determines whether or not the articulated vehicle 2 can travel through the passage 12 based on the travel plan line 10L. In the travel feasibility determination process P4, in addition to determining whether or not the articulated vehicle 2 can pass through the passage 12, the suitability of the steering angle of the towing vehicle 21 and the suitability of the bend angles of the coupling parts 28A·B are also determined. The suitability of the steering angle is determined based on whether or not there is a steering angle that exceeds the maximum bend angle on the route 10. The suitability of the bend angles of the coupling parts 28A·B is determined based on whether or not there is a bend angle that exceeds the maximum bend angle on the route 10 (threshold processing).

[0057] In the travel feasibility determination process P4, it is determined whether or not the articulated vehicle 2 can pass through the passage 12, based on the trajectory and attitude (orientation) of the towing vehicle 21 and the trajectory and attitude (orientation) of the two bogies 22A and B. In the travel feasibility determination process P4, the passing areas of the vehicles (the towing vehicle 21 and the two bogies 22) that make up the articulated vehicle 2 are superimposed to identify the outermost left and right points in the width direction, as shown in Figure 10. These outer left and right points at each position on the route 10 form the outer edge 10J in the width direction of the passing area 10R of the articulated vehicle 2, as shown in Figure 10.

[0058] In the driving feasibility determination process P4, if the passing area 10R of the articulated vehicle 2 is within the passage 12, it is determined that the articulated vehicle 2 can pass through the passage 12. On the other hand, if the passing area 10R of the articulated vehicle 2 enters the prohibited area 13 that spatially defines the passage 12, it is determined that the articulated vehicle 2 cannot pass through the passage 12. The result of the determination made in the driving feasibility determination process P4 is displayed on a display screen such as the liquid crystal display 151, for example.

[0059] As described above, the traveling simulation method of this example is a method of simulating traveling of the articulated vehicle 2 by setting the traveling plan line 10L that forms the trajectory of the rear axle center RC as the route 10. According to this traveling simulation method, it is possible to estimate the passing area 10R of the articulated vehicle 2, the steering angle of the towing vehicle 21, and the traction turn angle (turn angle) of the bogies 22A·B, which are towed vehicles, based on the traveling plan line 10L. Based on the passing area 10R of the articulated vehicle 2, the steering angle of the towing vehicle 21, and the traction turn angle of the bogies 22A·B, it is possible to efficiently determine whether or not the articulated vehicle 2 can travel through the passage 12 based on the traveling plan line 10L.

[0060] The trajectory 10F of the front axle center FC obtained by the traveling simulation method of this example can be a target trajectory when steering and controlling the towing vehicle 21, which is the leading vehicle of the articulated vehicles 2. If a control target point for the target trajectory is located at the front of the towing vehicle 21, meandering of the articulated vehicles 2 relative to the traveling plan line 10L can be suppressed, and control stability can be improved.

[0061] Furthermore, the driving plan line 10L in the driving simulation method of this embodiment is an appropriate combination of straight line trajectories, arc trajectories, and lane change trajectories. By using the application program executed by the simulation device 1 of this embodiment, the driving plan line 10L can be input simply by appropriately combining straight line trajectories, arc trajectories, and lane change trajectories, and driving plans for the articulated vehicles 2 can be made without special knowledge or skills.

[0062] It is preferable to input a plurality of types of travel plan lines in advance and determine whether or not travel is possible for each of them. When a plurality of travel plan lines are determined to be travelable, a process of selecting an optimal travel plan line may be executed. For example, a travel plan line with the smallest maximum steering angle during travel along the route 10 may be selected as the optimal travel plan line 10L, or a travel plan line with the smallest maximum turning angle during travel along the route 10 may be selected as the optimal travel plan line 10L. A travel plan line with the smallest maximum value of the widthwise distance between the outer edge 10J (FIG. 10) of the passing area 10R of the articulated vehicle 2 and the travel plan line 10L may be selected as the optimal travel plan line 10L. A travel plan line with the largest minimum value of the widthwise distance between the passing area 10R of the articulated vehicle 2 and the prohibited area 13 may also be selected as the optimal travel plan line 10L. Furthermore, a non-recommended area 131 where the passage of the articulated vehicle 2 is not recommended may be set in the passage 12. 11, the non-recommended area 131 can be set to be adjacent to the prohibited area 13. It is also possible to select the travel plan line that has the least number of overlapping points or the least overlapping area between the passing area 10R of the articulated vehicles 2 and the non-recommended area 131 as the optimal travel plan line 10L.

[0063] By determining the trajectory and orientation (posture) of the towing vehicle 21, it is possible to identify a magnetic detection area 10D (FIG. 12) through which the magnetic sensor module 3 passes as the combined vehicle 2 moves along the route 10. The magnetic detection area 10D is an area in which magnetism is detected by the magnetic sensor module 3 while the combined vehicle 2 is moving. Information on the magnetic detection area 10D is one piece of information obtained as a result of simulating the travel trajectory of the combined vehicle 2. The magnetic detection area 10D is useful information when planning the placement positions of magnetic markers on the route 10. By placing a magnetic marker in the magnetic detection area 10D, the combined vehicle 2 moving along the route 10 can detect the magnetic marker with a high degree of certainty.

[0064] Although specific examples of the present invention have been described in detail as examples, these specific examples merely disclose examples of the technology encompassed by the claims. Needless to say, 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 by utilizing publicly known technologies and the knowledge of those skilled in the art. [Explanation of symbols]

[0065] 1 Simulation device 1S Driving Simulation System 10 Routes 10L Travel Plan Line 10R passing area 10J Outer edge (of the passing area) 12(12A~C) Aisle 13 Forbidden Area 2 Consolidated vehicles 21 Traction vehicle 211 Front wheels (steering wheels) 211A front axle 212 Rear wheel 212A rear axle 22(22A·B) Cart 221 Front wheel 222 Rear wheel 222A rear axle 28(28A・B) Connection part 280 Traction axle 3 Magnetic Sensor Module 40 Control Unit 48 Map Database FC front axis center RC rear axle center

Claims

1. A method for simulating the running of a combination vehicle in which one or more bogies are connected in series, with a towing vehicle having steered front wheels and fixed-steered rear wheels, comprising the steps of: A process of setting a travel plan line along which a rear axle center RC, which is a midpoint of the axle of the rear wheels of the towing vehicle, is aligned; A process of determining a path of a front axle center FC, which is a midpoint of an axle of a front wheel of the towing vehicle, and a direction of the towing vehicle when the towing vehicle is driven so that the rear axle center RC is aligned with the driving plan line; determining the trajectory and orientation of the one or more bogies based on the trajectory of the front axle center FC and the orientation of the towing vehicle.

2. 2. The method according to claim 1, further comprising a process of determining a direction of a towing vehicle or a bogie directly towed by the towing vehicle or the bogie, based on a direction of the towing vehicle or the bogie at the front of the combination vehicle in the traveling direction, In the process of determining the trajectory and orientation of the one or more than two vehicles, A process of determining the orientation is executed in sequence from the towing vehicle or bogie on the front side in the traveling direction to the bogie on the rear side in the traveling direction, starting from the towing vehicle or bogie on the front side in the traveling direction, thereby determining the orientation of the one or more bogies; A method for simulating the running of articulated vehicles, which determines the trajectories of one or more bogies based on the trajectory of the front axle center FC, the orientation of the towing vehicle, and the orientations of the one or more bogies.

3. According to claim 1, the driving plan line is a trajectory that is configured by a straight line trajectory, a circular arc trajectory, and a lane change trajectory, a lane change trajectory that changes the position of the path in the width direction without changing the path direction before and after the lane change;

4. 2. A method for simulating a running of an articulated vehicle according to claim 1, further comprising a process of determining an area through which the towing vehicle and the one or more bogies pass as a passing area of ​​the articulated vehicle.

5. 5. The vehicle navigation system according to claim 4, further comprising a prohibited area in which the articulated vehicles are prohibited from protruding, A method for simulating traveling of an articulated vehicle, comprising a process for determining whether or not there is an area within a passing area of ​​the articulated vehicle that overlaps with the prohibited area.

6. 6. The method according to claim 1, further comprising: a threshold process for determining whether or not the steering angle of the towing vehicle exceeds a maximum value; and threshold processing for determining whether or not a towing bend angle, which is the angular deviation between the orientation of the towing vehicle or bogie at the front of the towing vehicle in the direction of travel and the orientation of the bogie directly towed by the towing vehicle or bogie, exceeds a maximum value.

7. A system for simulating the running of a combination vehicle in which one or more bogies are connected in series, with a towing vehicle having steered front wheels and fixed-steered rear wheels at the front, comprising: a processing unit that sets a driving plan line for aligning a rear axle center RC, which is a midpoint of the axle of the rear wheels of the towing vehicle, with respect to a route along which the combination vehicle is to be moved; a processing unit that determines a path of a front axle center FC, which is a midpoint of an axle of a front wheel of the towing vehicle, and a direction of the towing vehicle when the towing vehicle is driven so that the rear axle center RC is aligned with the driving plan line; a processing unit that determines the trajectory and orientation of the one or more bogies based on the trajectory of the front axle center FC and the orientation of the towing vehicle.

8. 8. The vehicle control system according to claim 7, further comprising a processing unit for determining an orientation of the towing vehicle or the bogie directly towed by the towing vehicle or the bogie, based on an orientation of the towing vehicle or the bogie at the front of the combination vehicles in the traveling direction, The processing unit for determining the trajectory and orientation of the one or more vehicles includes: A process of determining the orientation is executed in sequence from the towing vehicle or bogie on the front side in the traveling direction to the bogie on the rear side in the traveling direction, starting from the towing vehicle or bogie on the front side in the traveling direction, thereby determining the orientation of the one or more bogies; A driving simulation system for articulated vehicles configured to determine the trajectories of one or more bogies based on the trajectory of the front axle center FC, the orientation of the towing vehicle, and the orientation of the one or more bogies.

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