Guidance system

Abstract

To achieve a goal for simplifying the device configuration of a guided body and allow the guided body to easily travel along a route.SOLUTION: A guiding zone 20 is a guide zone for guiding an unmanned carrier 10 so that the unmanned carrier 10 as the guided body moves along a predetermined route C0. The guiding zone 20 includes a plurality of sub-patterns 21 arranged in series along the route C0. Each of the plurality of sub-patterns 21 is formed in a shape which becomes shorter from one end side(-x direction side) to the other end side(+x direction side) in a direction orthogonal to the route C0.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to Guidance system .

Background Art

[0002] Conventionally, in a factory, as a method of guiding an automatic guided vehicle (AGV), which is a guided object, to a target stop position, a guide tape is attached to the floor along the path from the start position to the stop position of travel, and a method in which the AGV travels on the detected guide tape while detecting the guide tape is generally known.

[0003] For example, two light-receiving element arrays for detecting the brightness and darkness of the contour of a guide tape are attached to an AGV such that the arrangement direction of a plurality of light-receiving elements in each light-receiving element array forms an angle of 45 degrees with respect to a center line perpendicular to the travel direction, and a guidance control device for an AGV that increases the detection sensitivity in the width direction of the guide tape (√2 times) is known (see Patent Document 1).

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] However, the guidance control device for an AGV described in Patent Document 1 requires a light-receiving element array in which a plurality of light-receiving elements are arranged, so the device configuration of the AGV is complicated and the cost is high. In addition, since the contour in the width direction of the guide tape is instantaneously detected for travel control, smooth travel is not achieved.

[0006] An object of the present invention is to simplify the device configuration of the guided object and to easily cause the guided object to travel along the path. [Means for solving the problem]

[0008] This invention One aspect of a guidance system The system is a guidance system in which a guided vehicle moves along a predetermined guidance band by detecting the guidance band, wherein the guidance band comprises a plurality of sub-patterns arranged in a continuous manner along a path, each of the plurality of sub-patterns is formed such that its width in the direction along the path decreases from one end to the other in the direction perpendicular to the path, and the guided vehicle comprises a sensor that detects the length of time it takes for the detection surface to cross at least one of the sub-patterns and a cutout pattern without the sub-patterns, and a control means that controls the direction of travel of the guided vehicle according to the length of the crossing time detected by the sensor. Each of the plurality of subpatterns is colored according to a predetermined sequence of arrangement patterns and arranged along the path, the sensor is capable of detecting the color of the subpattern, and the control means acquires the position information of the derivative according to the color detected by the sensor. It is characterized by the following: [Effects of the Invention]

[0009] According to the present invention, the device configuration of the derivative can be simplified, and the derivative can easily travel along the path. [Brief explanation of the drawing]

[0010] [Figure 1] This is a plan view showing an induction system according to an embodiment of the present invention. [Figure 2] This is a block diagram showing the functional configuration of an automated guided vehicle according to an embodiment. [Figure 3] This is a block diagram showing the circuit configuration of an optical sensor. [Figure 4] (a) is a plan view showing the path of the embodiment and the paths when the path is turned to the left or right from that path. (b) is a diagram showing the detection signals corresponding to the path in (a). [Figure 5] This is a flowchart showing the first driving control process. [Figure 6] This figure shows the three paths in the induction zone of the embodiment, and the detection signals corresponding to each path. [Figure 7](a) is a plan view showing the configuration of the guided zone of the first modified example. (b) is a plan view showing the configuration of the guided zone of the first modified example. (c) is a plan view showing the configuration of the guided zone of the first modified example. (d) is a plan view showing the configuration of the stop pattern of the first modified example. [Figure 8] (a) is a plan view showing the configuration of the induction band group in the second modified example. (b) is a plan view showing the configuration of the induction band group in the second modified example. [Figure 9] This is a block diagram showing the functional configuration of the third modified automated guided vehicle. [Figure 10] This is a flowchart showing the second driving control process. [Figure 11] This is a plan view showing the configuration of the induction zone in the fourth modified example. [Figure 12] This is a block diagram showing the functional configuration of the fourth modified automated guided vehicle. [Figure 13] This is a plan view showing the guide zone and automated guided vehicle of the fourth modified example. [Figure 14] This is a block diagram showing the functional configuration of the fifth modified example of an automated guided vehicle (AGV). [Figure 15] This is a plan view showing the state in which the right optical sensor detects a subpattern while the fifth modified automated guided vehicle (AGV) is traveling along a path, the state in which the left optical sensor detects a subpattern while the AGV is traveling along a path, the state in which the left optical sensor detects a subpattern while the AGV is traveling in a direction that has turned to the right from the path, and the state in which the left optical sensor detects a subpattern while the AGV is traveling in a direction that has turned to the left from the path. [Figure 16] This is a plan view showing the fifth modified example of an automated guided vehicle traveling along a sub-pattern path. [Modes for carrying out the invention]

[0011] Hereinafter, embodiments of the present invention and the first to fifth modification examples will be described in detail in order with reference to the attached drawings. Note that the embodiments and the first to fifth modification examples described below are subject to various technically preferable limitations for implementing the present invention, but the scope of the present invention is not limited to the following embodiments and illustrated examples.

[0012] (Embodiment) Referring to FIGS. 1 to 6, an embodiment of the present invention will be described. First, referring to FIGS. 1 to 3, the device configuration of this embodiment will be described. FIG. 1 is a plan view showing the guidance system 1 of this embodiment. FIG. 2 is a block diagram showing the functional configuration of the automated guided vehicle 10. FIG. 3 is a block diagram showing the circuit configuration of the optical sensor 14.

[0013] As shown in FIG. 1, the guidance system 1 of this embodiment includes an automated guided vehicle (AGV) 10 as a guided object and a guidance tape 20. The guidance system 1 is provided, for example, inside a factory. The automated guided vehicle 10 is, for example, a forklift or the like, and is an electric vehicle that carries goods or the like according to the work process inside the factory and autonomously travels unmanned on a predetermined path (course) inside the factory. The guidance tape 20 is a guidance tape arranged, for example, on the floor surface inside the factory, and is a guide part for guiding the automated guided vehicle 10 to travel on the path on the guidance tape 20, and is composed of, for example, a tape material.

[0014] The automated guided vehicle 10 is assumed to be guided and travel on a path C0 as a predetermined path of the guidance tape 20. The path C0 is a belt-shaped path whose extending direction is the direction in which the automated guided vehicle 10 should travel. The width (length in the x-axis direction) of the path C0 is the width from the most -x-direction side end to the most +x-direction side end of a sub-pattern 21 of the guidance tape 20 described later. In FIG. 1, on the plane of the guidance tape 20 (on the factory floor), a y-axis is taken along the straight path C0 of the guidance tape 20, the + direction of the y-axis is taken as the direction in which the automated guided vehicle 10 should travel, and an x-axis is taken in a direction perpendicular to the y-axis (left-handed system), and the same applies to the figures of other guidance tapes.

[0015] The automated guided vehicle (AGV) 10 comprises a housing 101, wheels 111, 112, 113, and 114, and an optical sensor 14. The housing 101 is the body of the AGV 10 and houses the various components. Wheel 111 is a front wheel located on the left front (+y direction, +x direction side) of the housing 101 when the forward direction (+y direction) of the AGV 10 is considered the front direction. Wheel 112 is a front wheel located on the right front (+y direction, -x direction side) of the housing 101. Wheel 113 is a rear wheel located on the left rear (-y direction, +x direction side) of the housing 101. Wheel 114 is a rear wheel located on the right rear (-y direction, -x direction side) of the housing 101.

[0016] The automated guided vehicle (AGV) 10 is, for example, a two-wheel drive system in which the front wheels 111 and 112 are the drive wheels. Furthermore, the AGV 10 is configured to steer left and right by the difference in rotational speed of the wheels 111 and 112, and does not have a steering function to change the angle of the wheels 111 and 112 relative to the forward direction. However, it is not limited to this configuration, and may also be a four-wheel drive system, etc.

[0017] The optical sensor 14 is, for example, positioned at the front (+y direction) and center in the left-right direction (x-axis direction) of the housing 101, and is an optical sensor that optically detects the guidance zone 20. The optical sensor 14 is, for example, composed of a reflective photointerrupter, has a detection surface on the factory floor side, and detects whether it is located in the sub-pattern 21 or stop pattern 31 of the guidance zone 20 (in which case the detection signal turns on) or not located in the sub-pattern 21 or stop pattern 31 (in which case the detection signal turns off) by emitting light to the floor side and receiving reflected light from the floor side. The automated guided vehicle 10 performs driving control such as steering (control of direction of travel) based on the time-series pattern of on / off of the detection signal detected by the optical sensor 14 (on / off time axis pattern).

[0018] The guide strip 20 has a plurality of sub-patterns 21, a cutout pattern 21N, and a stop pattern 31. The sub-patterns 21 have a shape in which the width (length) in the direction along the path C0 (+y direction) becomes shorter in the direction perpendicular to the path C0 (x-axis direction) from one end (the end on the -x direction side) to the other end (the end on the +x direction side). More specifically, the sub-patterns 21 are markers made of light-reflective tape or the like, and have a surface that reflects light. These markers have a triangular geometric pattern. The stop pattern 31 also has a surface that reflects light, similar to the sub-patterns 21. The cutout pattern 21N is the part of the guide strip 20 where there are no sub-patterns 21 or stop patterns 31, and the factory floor is exposed. Each of the plurality of cutout patterns 21N is positioned one between each of the plurality of sub-patterns 21 in the direction of travel of the automated guided vehicle 10.

[0019] The surfaces of the subpatterns 21 and stop patterns 31 of the guide band 20 reflect light, so the detection signal is turned on when the optical sensor 14 detects either the subpattern 21 or the stop pattern 31. Here, the cutout pattern 21N is assumed to have a surface that reflects light less than the subpatterns 21 or the stop pattern 31. In other words, the subpatterns 21 and the stop pattern 31 can be optically distinguished from the cutout pattern 21N by the detection signal of the optical sensor 14. Multiple subpatterns 21 are arranged in a continuous sequence along the path C0.

[0020] The stopping pattern 31 is a geometric pattern marker positioned at the final position of travel along path C0 to stop the automated guided vehicle (AGV) 10, and is composed of, for example, tape material. The stopping pattern 31 is a rectangle having a side length in the y-axis direction that is longer than the length of the -x side 211 where the AGV 10's path is longest in sub-pattern 21, so that it can be identified from sub-pattern 21 which the AGV 10 travels.

[0021] Here, one of the linear paths of the paths C0 is represented as path C1. The path C1 of the automated guided vehicle 10 on the guided zone 20 can be any position in the x-axis direction within the guided zone 20. Path C1 is a linear path from the starting position of the travel control to the stopping pattern 31. In this embodiment, an example is described in which the automated guided vehicle 10 starts traveling from the starting position in a factory, travels along the paths C0 on multiple sub-patterns 21, and stops at the stopping pattern 31. However, the travel path of the automated guided vehicle 10 is not limited to the above.

[0022] For example, the travel path of the automated guided vehicle (AGV) 10 may be configured to be placed over other objects to be traveled, such as outdoors. Furthermore, the travel path of the AGV 10 is not limited to a simple travel → stop path example, but may be a path indicated by a guidance zone in which a stop pattern is additionally placed between two adjacent sub-patterns 21 as an intermediate position. In addition, multiple stop patterns may be placed as intermediate positions. In such a path example, the travel control is performed as follows: travel of the AGV 10 on sub-pattern 21 → temporary stop at the stop pattern → ... → travel on sub-pattern 21 → final stop at stop pattern 31.

[0023] Next, the internal functional configuration of the automated guided vehicle (AGV) 10 will be explained with reference to Figures 2 and 3. As shown in Figure 2, the AGV 10 includes a CPU (Central Processing Unit) 11 as a control means, an operating unit 12, a RAM (Random Access Memory) 13, an optical sensor 14, a storage unit 15, drive control units 16L and 16R, and motors 17L and 17R. In the AGV 10, all parts except the motors 17L and 17R are connected via a bus 18.

[0024] The CPU 11 controls various parts of the automated guided vehicle 10. The CPU 11 reads a specified program from among the various programs stored in the memory unit 15, loads it into the RAM 13, and performs various processes in cooperation with the loaded program.

[0025] The control unit 12 receives various operation inputs from users such as workers and outputs the operation signals to the CPU 11.

[0026] RAM13 is a volatile semiconductor memory that can read and write information, providing a work area for the CPU11 to temporarily store data and programs.

[0027] The optical sensor 14 is a reflective photointerrupter that detects the presence or absence of the induction band 20 and outputs a detection signal to the CPU 11 indicating whether the detected induction band 20 is on or off. As shown in Figure 3, the optical sensor 14 has a light-emitting unit 141, a light-receiving unit 142, and resistors 143 and 144.

[0028] The light-emitting unit 141 and the light-receiving unit 142 are arranged in a pair on the detection surface of the optical sensor 14. The light-emitting unit 141 is a light source such as an LED (Light Emitting Diode) and is connected in series between the power supply unit and the ground unit via a resistor 143. Based on the power supply voltage, a voltage is applied through the resistor 143 to emit light (turn it on). The light-receiving unit 142 is a light-receiving unit such as a phototransistor and is connected in series between the power supply unit and the ground unit via a resistor 144. When it receives light emitted from the light-emitting unit 141 and reflected by the induction strip 20 on the factory floor, the resistor 144 pulls up an ON signal voltage corresponding to the detection of the induction strip 20 and outputs it to the CPU 11 as a detection signal for the induction strip 20.

[0029] The storage unit 15 is composed of a storage unit capable of reading and writing information such as flash memory, and stores various data and programs. In particular, the storage unit 15 stores the first driving control program P1 for executing the first driving control process described later.

[0030] The drive control unit 16L is a control circuit that controls the rotational speed and amount of motor 17L by means of PWM (Pulse Width Modulation) drive, etc., according to the control from the CPU 11. Motor 17L is a motor that rotates wheel 111, which is the left-hand drive wheel of the automated guided vehicle 10. The drive control unit 16R is a control circuit that controls the rotational speed and amount of motor 17R, which is the right-hand drive wheel of the automated guided vehicle 10, by means of PWM drive, etc., according to the control from the CPU 11. Motor 17R is a motor that rotates wheel 112, which is the right-hand drive wheel of the automated guided vehicle 10.

[0031] Next, the operation of the automated guided vehicle 10 will be explained with reference to Figures 4(a) to 4(6). Figure 4(a) is a plan view showing the path C1 and the paths C1L and C1R when the path turns left or right from path C1. Figure 4(b) is a diagram showing the detection signals SC1, SC1L, and SC1R corresponding to the paths C1, C1L, and C1R. Figure 5 is a flowchart of the first travel control process. Figure 6 is a diagram showing the three paths C2, C3, and C4 in the guidance zone 20a and the detection signals SC2, SC3, and SC4 corresponding to each path C2, C3, and C4.

[0032] First, an example of left and right steering control of the automated guided vehicle (AGV) 10 will be explained with reference to Figures 4(a) and 4(b). As shown in Figure 4(a), when the AGV 10 is to travel along a linear path C1 on the guided track 20, the path taken when the AGV 10 turns left (+x direction) from path C1 is defined as path C1L, and similarly, the path taken when it turns right (-x direction) is defined as path C1R. Furthermore, it is assumed that the AGV 10 is traveling at a predetermined speed (constant speed).

[0033] As shown in Figure 4(b), the detection signals of the optical sensor 14 corresponding to paths C1, C1L, and C1R are defined as detection signals SC1, SC1L, and SC1R, respectively. The detection signals of the optical sensor 14 alternate over time, as shown in detection signals SC1, SC1L, and SC1R, with an ON state duration corresponding to the detection of sub-pattern 21 and an OFF state duration corresponding to the detection of the missing pattern 21N. The ON state duration corresponds to the time the automated guided vehicle 10 crosses the sub-pattern 21. The OFF state duration corresponds to the time the automated guided vehicle 10 crosses the missing pattern 21N.

[0034] The detection signal SC1 corresponding to path C1 has the same duration for both the first ON state (T1) and the second ON state (T2) along the time axis. The ON state duration T1 is the duration of the ON state from the rising edge time t11, corresponding to the start of detection (start of ON state) of the first subpattern 21 of the detection signal SC1, to the falling edge time t12, corresponding to the end of detection (end of ON state) of the first subpattern 21. The ON state duration T2 is the duration of the ON state from the rising edge time t21, corresponding to the start of detection (start of ON state) of the second subpattern 21 of the detection signal SC1, to the falling edge time t22, corresponding to the end of detection (end of ON state) of the second subpattern 21. Note that the first OFF state duration T1N and the second OFF state duration T2N are of the same duration. The off-state duration T1N is the duration of the off state from the falling edge time t12 corresponding to the end of detection of the first subpattern 21 (start of detection of the first extraction pattern 21N) to the rising edge time t21 corresponding to the start of detection of the second subpattern 21 (end of detection of the first extraction pattern 21N). The on-state duration T2 is the duration of the off state from the falling edge time t22 corresponding to the end of detection of the second subpattern 21 (start of detection of the second extraction pattern 21N) to the rising edge time t31 (not shown) corresponding to the start of detection of the third subpattern 21 (end of detection of the second extraction pattern 21N).

[0035] For detection signal SC1L corresponding to path C1L, along the time axis, the duration of the second ON state T2 is shorter than the duration of the first ON state T1 (and the duration of the second OFF state T1N is longer than the duration of the first OFF state T1N). For detection signal SC1R corresponding to path C1R, along the time axis, the duration of the second ON state T2 is longer than the duration of the first ON state T1 (and the duration of the second OFF state T2N is shorter than the duration of the first OFF state T1N).

[0036] Therefore, when the CPU 11 detects an on / off time axis pattern of the detection signal SC1L, it determines that the vehicle is traveling on path C1L, which is curved to the left (+x direction) from path C1, and controls the rotation speed of motor 17L to be greater than the rotation speed of motor 17R via the drive control units 16L and 16R, thereby steering the vehicle to the right (-x direction) and moving the automated guided vehicle 10 in the +y direction to which it should be moving. Also, when the CPU 11 detects an on / off time axis pattern of the detection signal SC1R, it determines that the vehicle is traveling on path C1R, which is curved to the right from path C1, and controls the rotation speed of motor 17R to be greater than the rotation speed of motor 17L via the drive control units 16L and 16R, thereby steering the vehicle to the left and moving the automated guided vehicle 10 in the +y direction to which it should be moving.

[0037] Next, with reference to Figure 5, the first travel control process executed by the CPU 11 will be explained. As a premise, a guide zone 20 is arranged within the factory, and the automated guided vehicle 10 is assumed to travel from a starting position taken at any position in the x-axis direction within the path C0 of the guide zone 20 shown in Figure 1. Here, the automated guided vehicle 10 is assumed to accelerate from a stopped state at the starting position to a predetermined speed, maintain that predetermined speed, and travel at a constant speed. Furthermore, the time for this acceleration is assumed to be sufficiently short.

[0038] It is assumed that the automated guided vehicle 10 is initially positioned at a starting position corresponding to the desired travel position in the x-axis direction, with its direction of travel facing the +y direction. In the automated guided vehicle 10, for example, when an instruction to execute a first travel control process is input from a user (worker) via the operation unit 12, the CPU 11 executes the first travel control process according to the first travel control program P1 stored in the memory unit 15.

[0039] As shown in Figure 5, first, the CPU 11 starts driving control by controlling the rotation of the motors 17L and 17R via the drive control units 16L and 16R to a predetermined speed without steering, and acquires a detection signal from the optical sensor 14 as the first detection signal, which includes the period during which the induction band 20 remains in the ON state (step ST1). Then, the CPU 11 increments the variable i by 1 (step ST2). The initial value of the variable i is 1. Then, the CPU 11 acquires a detection signal from the optical sensor 14 as the i-th detection signal, which includes the next period during which the induction band 20 remains in the ON state (step ST3).

[0040] Then, the CPU 11 determines whether or not the stop pattern 31 has been detected based on whether or not the i-th detection signal acquired in step ST3 corresponds to the detection signal of the stop pattern 31 (step ST4). In step ST4, for example, if the duration of the ON state immediately preceding the detection signal is greater than or equal to the travel time of side 311 of the stop pattern 31, it is determined that the stop pattern 31 has been detected.

[0041] If stop pattern 31 is not detected (step ST4; NO), the CPU 11 compares the ON state duration of the (i-1)th detection signal obtained in step ST1 or ST3 with the ith detection signal (calculates the difference), and from the comparison result (calculated difference), calculates the control amount (such as rotational speed) for motors 17L and 17R that will cause the automated guided vehicle 10 to move in the direction it should move (step ST5).

[0042] In step ST5, for example, as shown in Figures 4(a) and 4(b), if the direction of travel of the automated guided vehicle 10 is turning left or right, the control amounts for motors 17L and 17R are calculated to steer the vehicle so that its direction of travel is in the +y direction to which it should be moving.

[0043] Then, the CPU 11 controls the rotation of motors 17L and 17R via drive control units 16L and 16R according to the control amount calculated in step ST5 (step ST6), and proceeds to step ST2. Steps ST5 and ST6 enable the rotation of motors 17L and 17R to respond quickly to the detection signal of the optical sensor 14 using PWM drive or the like. By repeating steps ST5 and ST6, the difference waveform of the detection signal (on state duration) gradually converges. If a stop pattern 31 is detected (step ST4; YES), the CPU 11 controls the motors 17L and 17R to stop via drive control units 16L and 16R (step ST7), and terminates the first driving control process.

[0044] As described above, according to this embodiment, the guidance system 1 is a guidance system in which an automated guided vehicle 10 moves along a predetermined guidance zone 20 by detecting the guidance zone 20. The guidance zone 20 comprises a plurality of sub-patterns 21 arranged in a series along a path C0. Each of the plurality of sub-patterns 21 is formed in a triangular shape, where the width in the direction along the path C0 (y-axis direction) becomes shorter from one end (-x direction) to the other end (+x direction) in the direction perpendicular to the path C0 (x-axis direction). The automated guided vehicle 10 comprises an optical sensor 14 that detects the length of the crossing time (on-state duration) when the detection surface crosses the sub-pattern 21, and a CPU 11 that controls the direction of travel of the automated guided vehicle 10 according to the length of the crossing time (on-off pattern over time) detected by the optical sensor 14.

[0045] Therefore, since optical element arrays and cameras are not used, the configuration of the automated guided vehicle 10 can be simplified, and because a detection signal with a periodic change in on / off time is used, the automated guided vehicle 10 can travel smoothly along path C0 while avoiding derailment.

[0046] Furthermore, the optical sensor 14 detects the induction band 20 by emitting light and receiving reflected light. The guidance band 20 has a surface that reflects light. Therefore, the guidance band 20 can be detected inexpensively, quickly, and accurately.

[0047] Furthermore, the guidance zone 20 has a stopping pattern 31 for stopping the automated guided vehicle 10. When the CPU 11 detects the stopping pattern 31 in response to a detection signal detected by the optical sensor 14, it controls the automated guided vehicle 10 to stop. Therefore, the automated guided vehicle 10 can be reliably stopped by the stopping pattern 31.

[0048] Here, as shown in Figure 6, we consider a guide band 20a in which the guide band 20 is replaced with sub-pattern 22 and sub-pattern 22N, instead of sub-pattern 21 and sub-pattern 21N. Sub-pattern 22 has the same configuration and arrangement as sub-pattern 21, but its size is larger than sub-pattern 21. Sub-pattern 22N has the same configuration and arrangement as sub-pattern 21N, but its size is larger than sub-pattern 21N.

[0049] Here, the paths C2, C3, and C4 of the automated guided vehicle 10 are assumed to be within the path C0 of the guided area 20a. Path C2 is a straight path in the direction (+y direction) along the path C0 of the guided area 20a, and is positioned to pass through the midpoint of the longest line segment in the direction perpendicular to the direction (+y direction) along the path C0 of the guided area 20a (x-axis direction). Path C3 is a straight path in the +y direction located on the +x side of path C2 (to the left as viewed from the automated guided vehicle 10). Path C4 is a straight path in the +y direction located on the -x side of path C1 (to the right as viewed from the automated guided vehicle 10).

[0050] Here, since the automated guided vehicle 10 travels at a constant speed, the direction of travel (+y direction) of paths C2 to C4 and the time axis of the detection signal of the optical sensor 14 are associated in the same direction. The detection signals SC2, SC3, and SC4 of the optical sensor 14 corresponding to paths C2, C3, and C4, respectively, are shown in Figure 6 with the time axis on the vertical axis.

[0051] When the optical sensor 14 of the automated guided vehicle 10 passes over sub-pattern 22 on path C2, detection signal SC2 is turned on, and similarly, when it passes over a skip pattern, the optical sensor 14 is turned off. Although the travel directions of paths C2 to C4 are the same, the duration of the continuously on state of detection signal SC2 corresponding to path C3 is shorter than the duration of the continuously on state of detection signal SC2 corresponding to path C2, and the duration of the continuously off state of detection signal SC3 is longer than the duration of the off state of detection signal SC2. The duration of the on state of detection signal SC4 corresponding to path C4 is longer than the duration of the on state of detection signal SC2 corresponding to path C2, and the duration of the off state of detection signal SC4 is shorter than the duration of the off state of detection signal SC2.

[0052] If the starting positions of the three automated guided vehicles (AGVs) 10 are spaced sufficiently apart in the x-axis direction so that they do not collide on path C0, then they can be controlled independently using the time-dependent pattern of the detection signals from the optical sensor 14, allowing the three AGVs 10 to travel parallel along path C0. Ideally, each of the three AGVs 10 would travel along paths C2, C3, and C4.

[0053] In the above configuration, the CPU 11 controls the direction of travel of the automated guided vehicle 10 based on the length of the crossing time (on-state duration) when crossing the sub-pattern 21 detected by the optical sensor 14, but the configuration is not limited to this. For example, the CPU 11 may control the direction of travel of the automated guided vehicle 10 based on the length of the crossing time (at least one of the on-state duration and off-state duration) when crossing at least one of the sub-pattern 21 and the blanking pattern 21N detected by the optical sensor 14.

[0054] (First variation) A first modified example of the above embodiment will be described with reference to Figures 7(a) to 7(d). Figure 7(a) is a plan view showing the configuration of the guide band 20A. Figure 7(b) is a plan view showing the configuration of the guide band 20B. Figure 7(c) is a plan view showing the configuration of the guide band 20C. Figure 7(d) is a plan view showing the configuration of the stop pattern 32.

[0055] In the above embodiment, a guide band 20 having multiple triangular subpatterns 21 and a stopping pattern 31 was described. In this modified example, guide bands 20A, 20B, and 20C having various subpatterns other than the subpattern 21, and a stopping pattern 32 different from the stopping pattern 31 will be described. In the description of guide bands 20A to 20C below, guide bands 20A to 20C have both a cutout pattern and a stopping pattern, but their description will be omitted.

[0056] As shown in Figure 7(a), a configuration using a guide band 20A may be used instead of the guide band 20 of the above embodiment. The guide band 20A has a plurality of subpatterns 23. The subpatterns 23 are the same as the subpatterns 21 of the above embodiment, but their shape and size are different. Specifically, the subpatterns 23 have a triangular shape with a shorter width in the y-axis direction compared to the subpatterns 21.

[0057] With this configuration, when the automated guided vehicle (AGV) takes a path along the y-axis, the number of detections of sub-pattern 23 (number of ON state durations) during travel along a predetermined length of the path becomes greater than the number of detections of sub-pattern 21. As a result, the number of times the detection signal of the optical sensor 14 is switched on and off during the predetermined time traveled along the path increases in the AGV 10, making the control of the direction of travel of the AGV 10 relative to the guide zone 20A more accurate.

[0058] Furthermore, as shown in Figure 7(b), a configuration using a guide band 20B may be used instead of the guide band 20 of the above embodiment. The guide band 20B has a plurality of subpatterns 21, 24. The subpatterns 24 are similar to the subpatterns 21 of the above embodiment, but are smaller in size. Also, each of the subpatterns 24 is positioned between each of the plurality of subpatterns 21.

[0059] With this configuration, when the automated guided vehicle (AGV) takes a path along the y-axis, the number of detections of subpatterns 21 and 24 during travel along a predetermined length of the path becomes greater than the number of detections of subpattern 21 alone. As a result, the number of times the detection signal of the optical sensor 14 is switched on and off during the predetermined time traveled along the path by the AGV 10 increases, thereby improving the accuracy of the control of the direction of travel of the AGV 10 relative to the guide zone 20B. However, the comparison of the duration of the on state of the detection signal in step ST5 of the first travel control process in the above embodiment is performed separately for the comparison of subpatterns 21 and for the comparison of subpatterns 24.

[0060] Furthermore, as shown in Figure 7(c), a configuration using a guided strip 20C may be used instead of the guided strip 20 of the above embodiment. The guided strip 20C has a plurality of subpatterns 25. The subpatterns 25 have a triangular shape and size similar to the subpattern 21 of the above embodiment, but their color changes in a gradient depending on the position in the x-axis direction. In other words, by detecting the color of the subpattern 25 as the automated guided vehicle 10 passes over it, the position of the automated guided vehicle 10 in the x-axis direction can be determined.

[0061] Here, the optical sensor 14 is a sensor capable of detecting the guidance band 20C (subpattern 27) and its color. Therefore, in the first travel control process of the above embodiment, in step ST5, the CPU 11 compares the ON duration of the detection signals, and further acquires the color (referred to as the detected color) of the detection signal from the optical sensor 14. Based on the comparison result of the detection signals and the x-axis position information corresponding to the detected color, the CPU 11 calculates the control amount for motors 17L and 17R to make the automated guided vehicle 10 travel in the direction it should travel. Since the detected color is used in addition to the comparison result of the detection signals, the control of the direction of travel of the automated guided vehicle 10 becomes more accurate.

[0062] Furthermore, as shown in Figure 7(d), a configuration using a stop pattern 32 may be used instead of the stop pattern 31 of the above embodiment. The stop pattern 32 has a plurality of strip-shaped portions 321. The plurality of strip-shaped portions 321 have a surface that reflects light, are strip-shaped portions that extend in the x-axis direction perpendicular to the path, and are arranged at predetermined intervals in the y-axis direction.

[0063] In the first driving control process, in step ST4, the CPU 11 determines whether or not it has detected a stop pattern 32 based on the detection signal from the optical sensor 14 acquired in step ST3.

[0064] As described above, according to this modified configuration, the guidance strip 20B has multiple subpatterns, including multiple subpatterns 21 arranged in a continuous line along the path, and multiple subpatterns 23 arranged between the multiple subpatterns 21 and smaller than the subpatterns 21. As a result, the number of times the detection signal of the optical sensor 14 is switched on and off within a predetermined time is increased, so the direction of travel of the automated guided vehicle 10 relative to the guidance strip 20B can be accurately controlled.

[0065] Furthermore, in the guidance zone 20C, the sub-pattern 25 changes color along the direction (x-axis direction) perpendicular to the path (y-axis direction). The optical sensor 14 can detect the color of the sub-pattern 25. The CPU 11 acquires the x-axis position information of the automated guided vehicle 10 according to the color detected by the optical sensor 14. Therefore, the x-axis position information of the automated guided vehicle 10 can be used to more accurately control the direction of travel of the automated guided vehicle 10 relative to the guidance zone 20C.

[0066] (Second variation) A second modified example of the above embodiment will be described with reference to Figures 8(a) and 8(b). Figure 8(a) is a plan view showing the configuration of the induction band group G1. Figure 8(b) is a plan view showing the configuration of the induction band group G2.

[0067] In the above embodiment, a guide band 20 having a plurality of triangular sub-patterns 21 and a stopping pattern 31 arranged in a line in the y-axis direction was described. In this modified example, guide band groups G1 and G2 having a plurality of guide bands having sub-patterns arranged in the y-axis direction will be described. In the following description of each guide band in guide band groups G1 and G2, each guide band has a release pattern and a stopping pattern, but their description will be omitted.

[0068] As shown in Figure 8(a), a configuration using a group of guide bands G1 may be used instead of the guide band 20 in the above embodiment. The group of guide bands G1 has guide bands 20D1, 20D2, and 20D3. Guide band 20D1 has a plurality of sub-patterns 25. Guide band 20D2 has a plurality of sub-patterns 26. Guide band 20D1 has a plurality of sub-patterns 27. Sub-patterns 25, 26, and 27 have a triangular shape similar to sub-pattern 21 in the above embodiment, but their colors are different from each other.

[0069] In the guidance zone 20D1, multiple sub-patterns 25 are arranged in a line along the path C01. Path C01 is a strip-shaped path extending in the direction (+y direction) in which the automated guided vehicle 10 should travel. In the guidance zone 20D2, multiple sub-patterns 26 are arranged in a line along the path C02. Path C02 is a strip-shaped path extending in the direction (+y direction) in which the automated guided vehicle 10 should travel. In the guidance zone 20D3, multiple sub-patterns 27 are arranged in a line along the path C03. Path C03 is a strip-shaped path extending in the direction (+y direction) in which the automated guided vehicle 10 should travel. Paths C01, C02, and C03 are arranged in parallel to each other at different positions along the x-axis. In other words, the guidance band group G1 consists of three parallel guidance bands: guidance band 20D1 (corresponding to route C01) composed of multiple sub-patterns 25, guidance band 20D2 (corresponding to route C02) composed of multiple sub-patterns 26, and guidance band 20D3 (corresponding to route C03) composed of multiple sub-patterns 27.

[0070] Here, the optical sensor 14 of the automated guided vehicle 10 is a sensor capable of detecting guide strips 20D1, 20D2, 20D3 (sub-patterns 25, 26, 27) and their colors. In the first travel control process of the above embodiment, in step ST5, the CPU 11 compares the ON state duration of the detection signals of the optical sensor 14 acquired in step ST3, and further acquires the color (referred to as the detected color) of the detection signal of the optical sensor 14. Based on the comparison result of the detection signals and the detected color, the CPU 11 calculates the control amount for motors 17L and 17R such that the automated guided vehicle 10 travels in the direction it should travel along path C01, C02, or C03. Since the detected color is used in addition to the comparison result of the detection signals, the control of the direction of travel of the automated guided vehicle 10 is made more accurate. In particular, since each of the three automated guided vehicles 10 can travel independently along their respective paths (paths C01, C02, or C03) in the guidance zones 20D1, 20D2, and 20D3, the three automated guided vehicles 10 can travel in parallel.

[0071] Furthermore, as shown in Figure 8(b), a configuration using a group of guided bands G2 may be used instead of the guided band 20 of the above embodiment. The group of guided bands G2 includes guided bands 20E1, 20E2, and 20E3. Each of the guided bands 20E1, 20E2, and 20E3 has a plurality of subpatterns 25, 26, and 27. In guided band 20E1, the plurality of subpatterns 25, 26, and 27 are arranged in a line along path C01 in a predetermined color sequence. In guided band 20E2, the plurality of subpatterns 25, 26, and 27 are arranged in a line along path C02 in a predetermined color sequence different from that of guided band 20E1. In guided band 20E3, the plurality of subpatterns 25, 26, and 27 are arranged in a line along path C03 in a predetermined color sequence different from that of guided bands 20E1 and 20E2. In other words, the guidance band group G2 consists of three parallel guidance bands: guidance band 20E1 (corresponding to path C01) in which multiple subpatterns 25, 26, and 27 are arranged in a first repeating sequence; guidance band 20E2 (corresponding to path C02) in which multiple subpatterns 25, 26, and 27 are arranged in a second repeating sequence; and guidance band 20E3 (corresponding to path C03) in which multiple subpatterns 25, 26, and 27 are arranged in a third repeating sequence.

[0072] Here, as the optical sensor 14, a sensor capable of detecting the guidance zone 20E (subpatterns 25, 26, 27) and their color (detection color) is used. Therefore, in the first travel control process, in step ST5, the CPU 11 compares the ON state duration of the detection signal of the optical sensor 14 acquired in step ST3, and further acquires the array pattern of the detection color from the detection signal of the optical sensor 14. Based on the comparison result of the detection signals and the array pattern of the detection color, the CPU 11 calculates the control amount for motors 17L and 17R such that the automated guided vehicle 10 travels in the direction it should travel along path C01, C02, or C03. Since the array pattern of the detection color is used in addition to the comparison result of the detection signals, the control of the direction of travel of the automated guided vehicle 10 becomes more accurate. In particular, since each of the three automated guided vehicles 10 can travel independently along each path (path C01, C02, or C03) of the guidance zone 20E1, 20E2, and 20E3, the three automated guided vehicles 10 can travel in parallel.

[0073] As described above, according to this modified version, the guidance zone groups G1 and G2 are guidance zone groups for running multiple automated guided vehicles (AGVs) 10 in parallel. Guidance zone group G1 comprises guidance zones 20D1, 20D2, and 20D3. Guidance zones 20D1, 20D2, and 20D3 extend along the y-axis and are arranged in parallel at different positions in the x-axis direction. Each of the guidance zones 20D1, 20D2, and 20D3 has multiple sub-patterns 25, 26, or 27 arranged along the paths C01, C02, or C03, each with the same color. The colors of the sub-patterns 25, 26, and 27 of each guidance zone 20D1, 20D2, and 20D3 are different from each other. The optical sensor 14 is capable of detecting the colors of the sub-patterns 25, 26, and 27. The CPU 11 acquires the x-axis position information of the AGVs 10 according to the detected color detected by the optical sensor 14. Therefore, by using the x-axis position information of the automated guided vehicle 10, the direction of travel of the automated guided vehicle 10 relative to the guide zones 20D1, 20D2, and 20D3 can be controlled more accurately.

[0074] Furthermore, the guidance zone group G2 includes guidance zones 20E1, 20E2, and 20E3. Guidance zones 20E1, 20E2, and 20E3 extend along the y-axis and are arranged in parallel at different positions in the x-axis direction. Each of the guidance zones 20E1, 20E2, and 20E3 has multiple sub-patterns 25, 26, and 27 arranged along paths C01, C02, or C03, each colored in a predetermined sequence. The sequence patterns of each guidance zone 20D1, 20D2, and 20D3 are different from each other. The optical sensor 14 is capable of detecting the colors of the sub-patterns 25, 26, and 27. The CPU 11 acquires the x-axis position information of the automated guided vehicle 10 according to the sequence pattern of the detected color detected by the optical sensor 14. Therefore, by using the x-axis position information of the automated guided vehicle 10, the direction of travel of the automated guided vehicle 10 relative to the guidance zones 20E1, 20E2, and 20E3 can be controlled more accurately.

[0075] (Third variation) A third modification of the above embodiment will be described with reference to Figures 9 to 10. Figure 9 is a block diagram showing the functional configuration of the automated guided vehicle 10A. Figure 10 is a flowchart showing the second travel control process.

[0076] In the above embodiment, the automated guided vehicle 10 is configured to travel along a strip-shaped path C0 based on a comparison of the duration of the ON state of the detection signal of the optical sensor 14 from the previous and current detection signals. In this modified example, the automated guided vehicle 10A is configured to travel along a linear path C1 based on a comparison of the detection signal of the optical sensor 14 with reference signal information, which is a time-series pattern of the ON / OFF state of the detection signal.

[0077] In this embodiment, the automated guided vehicle (AGV) 10A shown in Figure 9 is used as the device configuration. However, in the AGV 10A, parts that are the same as those in the AGV 10 of the embodiment are denoted by the same reference numerals, and their descriptions are omitted.

[0078] In this modified example, we describe an example in which the automated guided vehicle 10A shown in Figure 9 is controlled to travel along paths C2, C3, or C4 of the guided zone 20a shown in Figure 6. The guided zone 20a is assumed to have a plurality of sub-patterns 22, a skip pattern 22N, and a stop pattern 31. As shown in Figure 9, the automated guided vehicle 10A includes a CPU 11, an operation unit 12, a RAM 13, an optical sensor 14, a storage unit 15, drive control units 16L, 16R, and motors 17L, 17R.

[0079] The memory unit 15 stores a second travel control program P2 for executing a second travel control process, which will be described later, and reference signal information 40. The reference signal information 40 is information corresponding to the time-dependent patterns of the ON state duration and OFF state duration of the detection signal of the optical sensor 14 when the automated guided vehicle 10A travels along a predetermined linear path (paths C2, C3, C4) of the guidance zone 20a in Figure 9, and is information that serves as a reference for the travel of the automated guided vehicle 10 on the path of the guidance zone 20a.

[0080] Next, the operation of the automated guided vehicle 10A will be explained with reference to Figure 10. As shown in Figure 6, the automated guided vehicle 10A will take the following routes C2, C3, and C4 in the guided area 20a.

[0081] As shown in Figure 6, the time-dependent on / off patterns of detection signals SC2 to SC4 allow for the identification of which path C2, C3, or C4 the automated guided vehicle (AGV) 10A is traveling along. For this reason, for example, three AGVs 10A can be independently controlled to travel along paths C2 to C4 using the time-axis patterns of the detection signals from the optical sensor 14, allowing the three AGVs 10A to travel parallel along paths C2 to C4.

[0082] Next, with reference to Figure 10, the second travel control process performed by the automated guided vehicle 10A will be explained. As a premise, a guided area 20a is arranged within the factory, and the automated guided vehicle 10A is assumed to travel along one of the routes C2, C3, or C4 in Figure 6. Routes C2, C3, and C4 are all straight routes on the guided area 20a, in which multiple sub-patterns 22 of the guided area 20 are arranged, and a stopping pattern 31 is placed at the end. Therefore, the reference signal information 40 will include the reference signal information for route C2, the reference signal information for route C3, and the reference signal information for route C4.

[0083] It is assumed that the automated guided vehicle 10A is positioned in advance at the starting position on the route to be traveled, with its direction of travel facing the +y direction. In the automated guided vehicle 10A, for example, when an instruction to execute the second travel control process is input from a user (worker) via the operation unit 12, the CPU 11 executes the second travel control process according to the second travel control program P2 stored in the memory unit 15.

[0084] As shown in Figure 10, first, the CPU 11 receives initial setting information via the operation unit 12 (step ST11). The initial setting information includes identification information of the designated route on which the automated guided vehicle 10A will travel (route C2, C3, or C4) and start instruction information to start the automated guided vehicle 10A from running.

[0085] Then, the CPU 11 reads and acquires the reference signal information for the designated route (route C2, C3, or C4) from the reference signal information 40 stored in the memory unit 15, according to the identification information of the designated route among the initial setting information input in step ST11, and starts driving control by controlling the rotation of the motors 17L and 17R to a predetermined speed without steering via the drive control units 16L and 16R (step ST12).

[0086] Then, the CPU 11 acquires a detection signal of the induction band 20 from the optical sensor 14 (step ST13). The CPU 11 then determines whether or not the stop pattern 31 has been detected based on whether or not the detection signal acquired in step ST13 corresponds to the detection signal of the stop pattern 31 (step ST14). In step ST14, for example, if the duration of the ON state immediately preceding the detection signal is greater than or equal to the length of the y-axis direction of the stop pattern 31, it is determined that the stop pattern 31 has been detected.

[0087] If stop pattern 31 is not detected (step ST14; NO), the CPU 11 compares the reference signal information of the specified path obtained in step ST12 with the detection signal obtained in step ST13 (calculates the difference), and from the comparison result (calculated difference), calculates the control amount (such as rotational speed) for motors 17L and 17R to make the automated guided vehicle 10A travel along the specified path (step ST15).

[0088] In step ST15, for example, as shown in Figure 6, if the automated guided vehicle 10A is traveling on a path other than the designated path, the control amounts for motors 17L and 17R to steer it to move to the designated path are calculated. Also, as shown in Figures 4(a) and 4(b), if the automated guided vehicle 10A is on a path that curves to the left or right from the designated path, the control amounts for motors 17L and 17R to steer it back to the designated path are calculated.

[0089] Then, the CPU 11 controls the rotation of motors 17L and 17R via drive control units 16L and 16R according to the control amount calculated in step ST15 (step ST16), and proceeds to step ST13. By repeating steps ST15 and ST16, the difference waveform between the detected signal and the reference signal waveform gradually converges. If stop pattern 31 is detected (step ST14; YES), the CPU 11 controls motors 17L and 17R to stop via drive control units 16L and 16R (step ST17), and terminates the second driving control process.

[0090] As described above, according to this modified configuration, the CPU 11 compares the reference signal information, which is a time-series pattern of traverse time (on-state duration) that serves as the basis for the travel of the automated guided vehicle (AGV) 10A on the linear path of the guidance strip 20a, with the detection signal detected by the optical sensor 14, and controls the direction of travel of the AGV 10A based on the comparison result. Therefore, by pre-registering the reference signal information for the travel path, accurate travel control of the AGV 10A on that path is possible, and it is possible to apply this to multiple paths using multiple reference signal information. Furthermore, even if the AGV 10A deviates from the path (goes off), it can easily return to the path as long as it is on the guidance strip 20a. In addition, since multiple paths can be taken on one guidance strip 20a (one sub-pattern 22), even if a path becomes unusable on the guidance strip 20a due to changes in the factory layout or changes in the cargo storage area, the AGV can travel on a path other than the unusable path, eliminating the need to replace the guidance strip 20a.

[0091] In this modified example, the reference signal information 40 is configured to be set in advance, but is not limited to this. For example, if the arrangement patterns of multiple subpatterns of the guidance zone are the same in the extension direction, the reference signal information corresponding to the subpattern may be configured such that, in the second travel control process, the detection signal of the optical sensor 14 (the duration of the on state and the duration of the off state) when the automated guided vehicle first passes over the subpattern is used as reference signal information for the detection signal corresponding to the subpattern passed later.

[0092] (Fourth variation) A fourth modification of the above embodiment will be described with reference to Figures 11 to 13. Figure 11 is a plan view showing the configuration of the guided area 20F. Figure 12 is a block diagram showing the functional configuration of the automated guided vehicle 10B. Figure 13 is a plan view showing the guided area 20G and the automated guided vehicle 10B.

[0093] In the above embodiment, a guide zone 20 along a straight, strip-shaped path C0 was described. However, in this modified example, guide zones 20F and 20G along a curved, strip-shaped path C0, and an automated guided vehicle 10C suitable for guide zones 20F and 20G will be described.

[0094] As shown in Figure 11, the guide band 20F of this modified example has a plurality of subpatterns 21. In the guide band 20F, the plurality of subpatterns 21 are arranged along a curved, strip-shaped path C0 in the direction in which they should travel. Now, consider one of the curved paths C0, C5. For example, in the subpattern 21, the path C5 passes through the midpoint of the length between the two ends of the maximum length in the direction perpendicular to the path C5, and the plurality of subpatterns 21 are arranged such that the distance between each subpattern 21 on the path C5 is equal, and the distance between the cutout patterns on the path C5 is also equal.

[0095] When the automated guided vehicle 10 travels along path C5, the duration of each ON state corresponding to the detection of each subpattern 21 of the detection signal of the optical sensor 14 becomes the same, and similarly, the duration of each OFF state corresponding to the detection of each missing pattern also becomes the same. Therefore, similar to the guidance zone 20, the first travel control process can be executed on the automated guided vehicle 10 in the guidance zone 20F to control its travel within the curved, strip-shaped path C0.

[0096] However, when the automated guided vehicle 10 travels along path C0, there is a risk of an inner wheel difference occurring, where the trajectory of the front wheel (e.g., wheel 111) on the inside of the curve and the rear wheel (e.g., wheel 113) on the inside of the curve differ. The longer the wheelbase of the housing 101 (the distance between the front and rear wheels), the greater the inner wheel difference will be.

[0097] Therefore, as an alternative example of this modification, the automated guided vehicle 10B shown in Figures 12 and 13 will be used instead of the automated guided vehicle 10. However, for the automated guided vehicle 10B as well, the same reference numerals will be used for parts that are the same as those of the automated guided vehicle 10, and their explanations will be omitted.

[0098] As shown in Figure 12, the automated guided vehicle 10B includes a CPU 11, an operating unit 12, a RAM 13, optical sensors 14 and 14E, a storage unit 15, a drive control unit 16F, a steering control unit 16S, and motors 17F and 17S. Furthermore, as shown in Figure 13, the automated guided vehicle 10B includes wheels 111B, 112B, 113B, and 114B inside the housing 101, in addition to the optical sensors 14 and 14E.

[0099] The optical sensor 14 is located on the front side of the housing 101 in the forward direction, similar to the optical sensor 14 in the above embodiment. The optical sensor 14E has the same configuration as the optical sensor 14, but is located at the center of the housing 101 in the left-right direction and on the rear side in the forward direction.

[0100] The drive control unit 16F is a control circuit that controls the rotational speed and rotational amount of the motor 17F according to the control from the CPU 11. The motor 17F is a motor that rotates the wheels 111B and 112B, which are the drive wheels as the front wheels of the automated guided vehicle 10B, in the axial direction.

[0101] Wheel 111B is a front wheel located on the left front of the housing 101, relative to the forward direction. Wheel 112B is a front wheel located on the right front of the housing 101. Wheels 111B and 112B are connected via a drive shaft and are drive wheels rotated by motor 17F. Wheel 113B is a rear wheel located on the left rear of the housing 101. Wheel 114B is a rear wheel located on the right rear of the housing 101.

[0102] The steering control unit 16S is a control circuit that controls the steering angle of wheels 111B to 114B by controlling the rotational speed and amount of rotation of motor 17S according to the control from CPU 11. Motor 17S is a steering motor that rotates to change the steering angle of wheels 111B, 112B, 113B, and 114B with respect to the forward direction of the housing 101.

[0103] As shown in Figure 13, consider the case where the automated guided vehicle 10B travels along path C5 within path C0 on the guidance zone 20G. The guidance zone 20G, like the guidance zone 20F, has multiple sub-patterns 21. In the guidance zone 20G, the multiple sub-patterns 21 are arranged on the curved, strip-shaped path C0, similar to the guidance zone 20F. However, in Figure 13, the sub-patterns 21 are shown in white for clarity. The guidance zone 20G also has a stopping pattern 31 at the end of path C5.

[0104] The CPU 11 of the automated guided vehicle 10B performs the first driving control process, similar to the automated guided vehicle 10. However, in step ST3, the CPU 11 acquires the detection signal of optical sensor 14E in addition to the detection signal of optical sensor 14. In step ST5, the CPU 11 compares the ON state duration of the detection signal of optical sensor 14, and further calculates the control amount for motors 17F and 17S in the automated guided vehicle 10B to reduce the inner wheel difference of wheels 111B and 113B, based on the comparison result and the detection signals of optical sensors 14 and 14E.

[0105] In step ST6, the CPU 11 controls the drive control unit 16F and the steering control unit 16S according to the control amounts of the motors 17F and 17S calculated in step ST5. By using the detection signals of optical sensors 14 and 14E in addition to the comparison results of the detection signals, the automated guided vehicle 10B is precisely steered and its movement is controlled to minimize the inner wheel difference.

[0106] For example, as shown in Figure 13, suppose the automated guided vehicle 10B starts moving, the optical sensor 14 passes the second sub-pattern 21, the detection of the ON state duration of the optical sensor 14 ends, and it is found that it has become longer than the ON state duration detected in the previous detection, and a deviation to the right is detected. Then, in steps ST5 and ST6, steering control is performed to tilt the front wheels (wheels 111B, 112B) to the left. When the optical sensor 14E passes the second sub-pattern 21, the detection of the ON state duration of the optical sensor 14E ends, and because an inner wheel difference occurs in the optical sensor 14E, it makes a wider turn, resulting in an ON state duration longer than that detected by the optical sensor 14. In step ST5, the magnitude of the inner wheel difference is calculated based on the magnitude of this time difference in ON state duration, and the tilt angle of the rear wheels (wheels 113B, 114B) is set to minimize the inner wheel difference for the next detection cycle (step ST3), and the trajectory is corrected in step ST6.

[0107] According to this modified example, the path C0 in the direction of travel is curved (a curved strip). Multiple subpatterns 21 are arranged so that their traverse time (on-state duration) on path C0 is the same. Therefore, the direction of travel of the automated guided vehicle 10B on the curved path C0 can be controlled.

[0108] Furthermore, the automated guided vehicle (AGV) 10B has optical sensors 14 and 14E positioned at different locations along the direction of travel. The CPU 11 controls the direction of travel of the AGV 10B to reduce the inner wheel difference of the AGV 10B according to the time-dependent pattern of the length of the crossing time (on-state duration) detected by the optical sensors 14 and 14E. As a result, the inner wheel difference of the AGV 10B when traveling on the curved path C0 can be reduced, the starting correction time can be shortened, it can respond to wheel slip during travel and sharp curve tracing, and it can prevent the AGV 10B from deviating from the path C0. Furthermore, according to this modified example, the guided area 20 can be formed in a loop shape, and the automated guided vehicle 10 can continuously circle the same route while repeatedly driving and stopping at predetermined positions.

[0109] (Fifth variation) A fifth modification of the above embodiment will be described with reference to Figures 14 to 16. Figure 14 is a block diagram showing the functional configuration of the automated guided vehicle 10C of this modification. Figure 15 is a plan view showing state a when the right optical sensor 14R detects the sub-pattern 21 while the automated guided vehicle 10C is traveling on path C1, state b when the left optical sensor 14L detects the sub-pattern 21 while the automated guided vehicle 10C is traveling on path C1, state c when the left optical sensor 14L detects the sub-pattern 21 while the automated guided vehicle 10C is traveling in a direction that curves to the right from path C1, and state d when the left optical sensor 14L detects the sub-pattern 21 while the automated guided vehicle 10A is traveling in a direction that curves to the left from path C1. Figure 16 is a plan view showing the state in which the automated guided vehicle 10D of this modification is traveling on path C1 of the sub-pattern 21.

[0110] In the above embodiment, an automated guided vehicle (AGV) 10 equipped with one optical sensor 14 was used. However, this modified example uses AGVs 10C and 10D equipped with an optical sensor 14 and further optical sensors 14L and 14R.

[0111] First, the modified automated guided vehicle 10C will be described with reference to Figures 14 and 15. However, for the automated guided vehicle 10C (and the parts of the automated guided vehicle 10D described later), parts that are the same as those of the automated guided vehicle 10 will be given the same reference numerals and their descriptions will be omitted.

[0112] As shown in Figure 14, the modified automated guided vehicle 10C comprises, internally, a CPU 11, an operating unit 12, a RAM 13, optical sensors 14, 14L, 14R, a storage unit 15, drive control units 16L, 16R, and motors 17L, 17R.

[0113] As shown in Figure 15, in state a, when the automated guided vehicle 10C is traveling along path C1 and the optical sensor 14R detects the subpattern 21 of the guide zone 20, the optical sensor 14L has the same configuration as the optical sensor 14, but is positioned to the left (+x direction) of the optical sensor 14 with respect to the forward direction of the automated guided vehicle 10C. The optical sensor 14R has the same configuration as the optical sensor 14, but is positioned to the right (-x direction) of the optical sensor 14. In this way, the optical sensors 14L, 14, and 14R are arranged in a single row at equal intervals along the left-right direction (x-axis direction) of the housing 101.

[0114] As shown in state a of Figure 15, the automated guided vehicle 10C travels along the path C1, which is arranged on the sub-pattern 21 of the guide zone 20, from the -y direction to the +y direction. Then, as shown in state a, of the optical sensors 14L and 14R, optical sensor 14R first detects edge 212 of the sub-pattern 21, and an ON rising edge occurs with the detection signal. Let the time of this ON rising edge be time t0. Edge 212 is the hypotenuse on the entry side (-y direction side) of the automated guided vehicle 10C in the sub-pattern 21.

[0115] Then, as shown in Figure 15, in state b, when the automated guided vehicle 10C is traveling along path C1 and the optical sensor 14L detects the subpattern 21, the optical sensor 14L detects the edge 212 of the subpattern 21 in the automated guided vehicle 10C traveling along path C1, and an ON rising edge occurs in the detection signal. Let the time of this ON rising edge be time t1. The difference time between time t1 and time t0, Δt0 = t1 - t0, is calculated.

[0116] Also, similar to state a in Figure 15, consider the state where the automated guided vehicle 10C is traveling in the direction of turning right from path C1, and the optical sensor 14R detects edge 212 of subpattern 21, causing an ON rising edge in the detection signal. Let the time of this ON rising edge be time t0. Then, in Figure 15, the automated guided vehicle 10C is traveling in the direction of turning right from path C1, and the optical sensor 14L detects edge 212 of subpattern 21, resulting in state c where an ON rising edge occurs in the detection signal. Let the time of this ON rising edge be time t1R. The difference time between time t1R and time t0, ΔtR = t1R - t0 < Δt0, is calculated.

[0117] Also, similar to state a in Figure 15, consider the state where the automated guided vehicle 10C is traveling in the direction of turning left from path C1, and the optical sensor 14R detects edge 212 of subpattern 21, causing an ON rising edge in the detection signal. Let the time of this ON rising edge be time t0. Then, in Figure 15, the automated guided vehicle 10C is traveling in the direction of turning left from path C1, and the optical sensor 14L detects edge 212 of subpattern 21, resulting in state d where an ON rising edge occurs in the detection signal. Let the time of this ON rising edge be time t1L. The difference time between time t1L and time t0, ΔtL = t1L - t0 > Δt0, is calculated.

[0118] The difference times Δt0, ΔtL, and ΔtR have the relationship ΔtR < Δt0 < ΔtL. In other words, by obtaining the start time of the ON state duration from the detection signals of optical sensors 14L and 14R, it is possible to determine from these difference times whether the automated guided vehicle 10C is traveling along path C1, whether it is traveling in a direction that curves to the right from path C1 and the degree of that rightward curve, and whether it is traveling in a direction that curves to the left from path C1 and the degree of that leftward curve. Δt0 is assumed to be, for example, measured in advance and stored in the memory unit 15.

[0119] The CPU 11 of the automated guided vehicle 10C performs the first travel control process, similar to the automated guided vehicle 10. However, in step ST3, the CPU 11 acquires the detection signals of optical sensors 14L and 14R in addition to the detection signal of optical sensor 14. In step ST5, the CPU 11 compares the detection signals of optical sensors 14, and further acquires Δt0 from the storage unit 15 to calculate the difference in rising time of the ON state of the detection signals of optical sensors 14L and 14R. Based on the comparison result of the detection signals and the comparison result of the difference time and Δt0, the CPU 11 calculates the control amount for motors 17L and 17R to make the automated guided vehicle 10C travel in the direction it should travel. Since the difference in rising time of the ON state of the detection signals is used in addition to the comparison result of the detection signals, the automated guided vehicle 10C is steered more accurately.

[0120] As described above, according to this modified configuration, the automated guided vehicle (AGV) 10C has optical sensors 14L and 14R positioned at different locations in the x-axis direction, perpendicular to the direction of travel (y-axis direction). The CPU 11 controls the direction of travel of the AGV 10C according to the difference between the start time (rise time) of the crossing time (on-state duration) detected by optical sensor 14L and the start time (rise time) of the crossing time (on-state duration) detected by optical sensor 14R. This allows for accurate control of the direction of travel of the AGV 10C. In particular, by combining the comparison result of the detection signals of optical sensor 14 and the difference time between optical sensors 14L and 14R to control the direction of travel of the AGV 10A, the direction of travel of the AGV 10C can be controlled more accurately, and false detections due to factory floor surfaces or tire slippage can be reduced.

[0121] As shown in Figure 16, an automated guided vehicle (AGV) 10D may be used instead of the AGV 10C. The configuration of the AGV 10D is the same as that of the AGV 10C, but the positions of the optical sensors 14L and 14R are different. In the AGV 10C, the optical sensors 14L, 14, and 14R were arranged at equal intervals on a line perpendicular to the forward direction (in the x-axis direction), but in the AGV 10D, the optical sensors 14L, 14, and 14R are arranged at equal intervals on line 140.

[0122] Here, line 140 is a line segment parallel to side 212. Therefore, when the automated guided vehicle 10D is traveling along path C1, the time t1 based on the rising edge of the detection signal of optical sensor 14L and the time t0 based on the rising edge of the detection signal of optical sensor 14R are the same, resulting in a difference time Δt0 = t1 - t0 = 0, making it easy to determine that the automated guided vehicle 10D is traveling along path C1.

[0123] The above description discloses an example in which the storage unit 15 is used as a computer-readable medium for the program according to the present invention, but the invention is not limited to this example. Portable recording media such as CD-ROMs can be used as other computer-readable media. Furthermore, carrier waves can also be used as a medium for providing the program data according to the present invention via a communication line.

[0124] The above embodiments and modifications are merely examples of the induction band, induction band group, induction system, induction method, and program according to the present invention, and are not limited thereto. For example, at least two of the above embodiments and the first to fourth modifications may be appropriately combined.

[0125] Furthermore, the guidance system in the above embodiment and its modified form may be combined with a camera visible light communication system. The camera visible light communication system is, for example, a system in which a camera is installed on an automated guided vehicle (AGV), and the camera captures images of multiple light sources that are pre-installed in a three-dimensional space such as a factory and have their position information set, performs image analysis, and obtains (positions) the position information of the AGV relative to the multiple light sources from the analysis results. Since each of the multiple light sources emits light of multiple colors in a predetermined pattern (in a different order) from each other, the ID of each light source can be identified by analyzing the predetermined pattern of the captured light.

[0126] In addition, the camera visible light communication system, as an alternative configuration, involves installing a light source on the automated guided vehicle (AGV), setting up multiple cameras with pre-configured positional information within a 3D space such as a factory, capturing images of the 3D space including the AGV with the multiple cameras, performing image analysis, and obtaining (positioning) the AGV's position information corresponding to the light source location from the analysis results.

[0127] In a guidance system that combines a camera visible light communication system, for example, positional information of a guidance zone provided in a three-dimensional space such as a factory can be set in advance. If the automated guided vehicle (AGV) of the above embodiment and its modified form deviates from the guidance zone, including the route, due to wheel slippage or the like while traveling along the route, the camera visible light communication system can acquire the positional information of the AGV, and based on this positional information, the AGV can be returned to the guidance zone and route.

[0128] Furthermore, while the above embodiments and modifications describe a configuration in which the automated guided vehicle detects the dielectric using an optical sensor, the system is not limited to this. For example, as a configuration for detecting the guide band, a magnetic sensor may be used instead of an optical sensor, and the guide band may be made of a magnetic material such as magnetic tape.

[0129] Furthermore, as a configuration for detecting the induction band, a capacitive proximity sensor may be used instead of an optical sensor, and the induction band may be composed of a predetermined material that can be detected by capacitance. A capacitive proximity sensor is a non-contact type sensor that utilizes an electric field and detects the presence or absence of an object by a change in capacitance. The object can be a conductor such as metal, or a dielectric such as water, oil, glass, plastic, or paper. For this reason, a conductor such as metal or a dielectric such as plastic can be used as the predetermined material for the induction band as the object.

[0130] Alternatively, instead of an optical sensor, a distance measuring sensor may be used to detect the guidance band, and the guidance band may be configured to have a three-dimensional structure. The distance measuring sensor is a sensor that measures the distance to the exposed surface (the surface of the sub-pattern or cutout pattern of the guidance band) perpendicular to the xy plane. For example, the stopping pattern of the guidance band may be configured with multiple protrusions arranged on a flat plate.

[0131] While embodiments and variations of the present invention have been described, the scope of the present invention is not limited to the embodiments and variations described above, but includes the scope of the invention as described in the claims and its equivalents. The invention described in the claims initially attached to the application for this patent is listed below. The claim numbers listed below are the same as those in the claims initially attached to the application for this patent. [Note] <Claim 1> A guide band for guiding a derivative to move along a predetermined path, It comprises a plurality of subpatterns arranged in a series along the aforementioned path, Each of the aforementioned subpatterns is formed such that its width in the direction along the path decreases from one end to the other in the direction perpendicular to the path. A guided zone characterized by the following features. <Claim 2> The derivative detects the induction band by the emission of light and the reception of reflected light, The induction band has a surface that reflects the light, The guided zone according to feature 1. <Claim 3> Each of the aforementioned subpatterns is colored according to a predetermined order and arranged along the path. The guided zone according to feature 1 or 2. <Claim 4> The sub-pattern changes color along a direction perpendicular to the path. The guided zone according to feature 1 or 2. <Claim 5> The induction band has a stopping pattern for stopping the derivative, The guided zone according to feature 1 or 2. <Claim 6> The aforementioned path is curved, The plurality of subpatterns are arranged such that the traverse time of the derivative on the path is the same. The guided zone according to feature 1 or 2. <Claim 7> A group of guide bands for running multiple derivatives in parallel, A plurality of guide bands as described in claim 1 or 2, The aforementioned multiple induction bands are arranged in parallel. A group of induction zones characterized by the following features. <Claim 8> Each of the aforementioned multiple guide bands is provided with a plurality of the aforementioned subpatterns, which are the same color and arranged along the path. The subpatterns of each of the aforementioned derivatives have different colors from each other. The group of guided zones according to feature 7. <Claim 9> Each of the aforementioned multiple guide bands is provided with a plurality of sub-patterns arranged along the path, each sub-pattern having a predetermined sequence of colors. The arrangement patterns of each of the aforementioned derivatives are different from each other. The group of guided zones according to feature 7. <Claim 10> An induction system in which a guided vehicle moves along a predetermined guided band by detecting the guided band, The aforementioned guided zone is It has multiple subpatterns arranged in a sequence along the path, Each of the aforementioned subpatterns is formed such that its width in the direction along the path decreases from one end to the other in the direction perpendicular to the path. The derivative is, A sensor that detects the length of time it takes for the detection surface to cross at least one of the subpattern and the blank pattern without the subpattern, A control means for controlling the direction of travel of the derivative according to the length of the transverse time detected by the sensor, Equipped with, A guidance system characterized by the following: <Claim 11> The control means compares reference signal information, which is a time-series pattern of crossing times that serves as a reference for the movement of the vehicle on the path of the guided zone, with a detection signal detected by the sensor, and controls the direction of travel of the vehicle based on the comparison result. The induction system according to feature 10. <Claim 12> The aforementioned sensor is an optical sensor that detects the induction band by the emission of light and the reception of reflected light. The induction band has a surface that reflects the light, The induction system according to claim 10 or 11, characterized in that it is the same as described in claim 10 or 11. <Claim 13> The sensor comprises a first sensor and a second sensor positioned at different locations in directions intersecting the direction of travel. The control means controls the direction of travel of the vehicle being driven based on the difference between the start time of the crossing time detected by the first sensor and the start time of the crossing time detected by the second sensor. The induction system according to claim 10 or 11, characterized in that it is the same as described in claim 10 or 11. <Claim 14> Each of the aforementioned subpatterns is colored according to a predetermined sequence of arrangement patterns and arranged along the path. The sensor is capable of detecting the color of the subpattern, The control means acquires the position information of the derivative according to the color detected by the sensor. The induction system according to claim 10 or 11, characterized in that it is the same as described in claim 10 or 11. <Claim 15> The sub-pattern changes color along a direction perpendicular to the path. The sensor is capable of detecting the color of the subpattern, The control means acquires the position information of the derivative according to the color detected by the sensor. The induction system according to claim 10 or 11, characterized in that it is the same as described in claim 10 or 11. <Claim 16> The induction band has a stopping pattern for stopping the derivative, The control means, upon detecting the stop pattern in response to the detection signal detected by the sensor, controls the controlled vehicle to stop. The induction system according to claim 10 or 11, characterized in that it is the same as described in claim 10 or 11. <Claim 17> The aforementioned path is curved, The sensor has a third sensor and a fourth sensor arranged at different positions along the direction of travel. The control means controls the direction of travel of the vehicle to reduce the inner wheel difference of the vehicle, according to the length of the transverse time detected by the third sensor and the fourth sensor. The induction system according to claim 10 or 11, characterized in that it is the same as described in claim 10 or 11. <Claim 18> A guidance method performed by a guidance system, comprising: a guidance band having a plurality of subpatterns arranged in a series along a predetermined path; and a driven vehicle equipped with a sensor that detects the length of time it takes to cross at least one of the subpatterns and a blank pattern without the subpatterns, wherein the driven vehicle moves along the guidance band, The control process includes controlling the direction of travel of the derivative based on the length of the transverse time detected by the sensor, Each of the aforementioned subpatterns is formed such that its width in the direction along the path decreases from one end to the other in the direction perpendicular to the path. An induction method characterized by the following: <Claim 19> A computer for a guidance system comprising a guidance band having a plurality of subpatterns arranged in a sequence along a predetermined path, and a driven vehicle equipped with a sensor that detects the length of time it takes to cross at least one of the subpatterns and a blank pattern without the subpatterns, wherein the driven vehicle moves along the guidance band, The sensor is configured to function as a control means for controlling the direction of travel of the vehicle to be driven based on the length of the transverse time detected by the sensor. Each of the aforementioned subpatterns is formed such that its width in the direction along the path decreases from one end to the other in the direction perpendicular to the path. A program characterized by the following features. [Explanation of Symbols]

[0132] 1. Guidance System 10, 10A, 10B, 10C, 10D Automated Guided Vehicles 101 cabinets 111,112,113,114,111B,112B,113B,114B Wheel 11 CPU 12 Control section 13 RAM 14, 14L, 14R, 14E Optical Sensors 141 Light-emitting part 142 Light receiving part 143,144 resistors 15 Storage section 16L, 16R, 16F Drive Control Unit 16S Steering Control Unit 17L, 17R, 17F, 17S motors 18 bus G1, G2 Guidance Zone Group Guidance bands 20, 20a, 20A, 20B, 20C, 20D1, 20D2, 20D3, 20E1, 20E2, 20E3, 20F, 20G 21, 22, 23, 24, 25, 26, 27 Subpatterns 21N, 22N punch pattern 211,212 sides 31,32 Stopping Patterns 311 sides 321 Band-shaped portion Routes C0, C01, C02, C03, C1, C1L, C1R, C2, C3, C4, C5

Claims

1. An induction system in which a guided vehicle moves along a predetermined guided band by detecting the guided band, The aforementioned guided zone is It has multiple subpatterns arranged in a sequence along the path, Each of the aforementioned subpatterns is formed such that its width in the direction along the path decreases from one end to the other in the direction perpendicular to the path. The derivative is, A sensor that detects the length of time it takes for the detection surface to cross at least one of the subpattern and the blank pattern without the subpattern, A control means for controlling the direction of travel of the derivative according to the length of the transverse time detected by the sensor, Equipped with, Each of the aforementioned subpatterns is colored according to a predetermined sequence of arrangement patterns and arranged along the path. The sensor is capable of detecting the color of the subpattern, The control means acquires the position information of the derivative according to the color detected by the sensor. A guidance system characterized by the following:

2. A guidance system in which a guided vehicle moves along a guided band by detecting a predetermined guided band, The aforementioned guided zone is It has multiple subpatterns arranged in a sequence along the path, Each of the aforementioned subpatterns is formed such that its width in the direction along the path decreases from one end to the other in the direction perpendicular to the path. The derivative is, A sensor that detects the length of time it takes for the detection surface to cross at least one of the subpattern and the blank pattern without the subpattern, A control means for controlling the direction of travel of the derivative according to the length of the transverse time detected by the sensor, Equipped with, The sub-pattern changes color along a direction perpendicular to the path. The sensor is capable of detecting the color of the subpattern, The control means acquires the position information of the derivative according to the color detected by the sensor. A guidance system characterized by the following:

3. An induction system in which a guided vehicle moves along a guided band by detecting a predetermined guided band, The aforementioned guided zone is It has multiple subpatterns arranged in a sequence along the path, Each of the aforementioned subpatterns is formed such that its width in the direction along the path decreases from one end to the other in the direction perpendicular to the path. The derivative is, A sensor that detects the length of time it takes for the detection surface to cross at least one of the subpattern and the blank pattern without the subpattern, A control means for controlling the direction of travel of the derivative according to the length of the transverse time detected by the sensor, Equipped with, The induction band has a stopping pattern for stopping the derivative, The control means, upon detecting the stop pattern in response to the detection signal detected by the sensor, controls the controlled vehicle to stop. A guidance system characterized by the following:

4. An induction system in which a guided vehicle moves along a guided band by detecting a predetermined guided band, The aforementioned guided zone is It has multiple subpatterns arranged in a sequence along the path, Each of the aforementioned subpatterns is formed such that its width in the direction along the path decreases from one end to the other in the direction perpendicular to the path. The derivative is, A sensor that detects the length of time it takes for the detection surface to cross at least one of the subpattern and the blank pattern without the subpattern, A control means for controlling the direction of travel of the derivative according to the length of the transverse time detected by the sensor, Equipped with, The aforementioned path is curved, The sensor has a third sensor and a fourth sensor arranged at different positions along the direction of travel. The control means controls the direction of travel of the vehicle to reduce the inner wheel difference of the vehicle, according to the length of the transverse time detected by the third sensor and the fourth sensor. A guidance system characterized by the following:

5. The control means compares reference signal information, which is a time-series pattern of crossing times that serves as a reference for the movement of the induced vehicle on the path of the guided zone, with a detection signal detected by the sensor, and controls the direction of travel of the induced vehicle based on the comparison result. The induction system according to any one of claims 1 to 4.

Images