JP2020198010A - Automatic guided vehicle, and control method and program of automatic guided vehicle - Google Patents

Abstract

To provide an automatic guided vehicle capable of avoiding an obstacle without losing a guide line serving as a marker on a traveling path.SOLUTION: An automatic guided vehicle 100 includes a drive unit 40, a control unit 10, a path detection unit 31 that detects a guide line marking a traveling path, and an obstacle detection unit 32 that detects an obstacle. The control unit 10 controls the drive unit 40 so that the vehicle travels based on the guide line detected by the path detection unit 31. When the obstacle detection unit 32 detects an obstacle, the control unit obtains an avoidance quantity needed to avoid the obstacle. When the avoidance quantity falls within a predetermined avoidable width, the control unit controls the drive unit 40 so that the vehicle travels while avoiding the obstacle.SELECTED DRAWING: Figure 1

Description

The present invention relates to an automatic guided vehicle that automatically moves using a tape or the like laid on a floor surface or the like as a guide, a control method and a program for the automatic guided vehicle.

Conventionally, automatic guided vehicles have been used for transporting goods in factories, and technological development to improve the control of automatic guided vehicles is also underway. For example, Patent Document 1 describes an automatic guided vehicle that moves along a guide line (a line that serves as a mark of a traveling route) provided on a road surface, by providing a finite state machine (FSM: Fine State Machine). An automated guided vehicle that can easily expand functions such as object avoidance is described.

International Publication No. 2016/199312

The automatic guided vehicle described in Patent Document 1 can be easily expanded in function by a simple algorithm by providing a plurality of FSMs having different priorities. For example, the automatic guided vehicle can operate to avoid obstacles by providing an FSM that turns to the right to avoid obstacles when it detects an obstacle and an FSM that operates in the opposite direction to the maneuvering for avoidance. I am trying to do it. However, when the avoidance operation is actually performed by these FSMs, it is not possible to return to the place where the guide line can be detected, and a situation may occur in which the guide line is lost. This is because it may not be possible to return to the original position due to a slight deviation of the turning angle even if the maneuver is performed in the opposite direction, or the guide line itself may change direction after the avoidance operation. When such a situation occurs, the automatic guided vehicle cannot move along the guide line.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide an automatic guided vehicle or the like capable of avoiding obstacles without losing sight of a guide line that serves as a mark of a traveling route.

In order to achieve the above object, the automatic guided vehicle according to the first aspect of the present invention is
An automatic guided vehicle equipped with a drive means and a control means.
A route detecting means for detecting a guide line indicating a traveling route, and
Obstacle detection means for detecting obstacles,
With more
The control means
The driving means is controlled so as to travel based on the guide line detected by the route detecting means.
When the obstacle detecting means detects the obstacle, an avoidance amount for avoiding the obstacle is acquired, and if the avoidance amount is within a predetermined avoidable range, the vehicle travels while avoiding the obstacle. The driving means is controlled.

The control unit
When the obstacle detecting means detects the obstacle, the width of the space where the obstacle does not exist is acquired in the traveling direction, and if the width is equal to or larger than a predetermined passable width, the vehicle travels while avoiding the obstacle. To control the driving means,
You may do so.

The route detecting means detects the guide line by scanning the front upper part of the automatic guided vehicle.
You may do so.

The guide line is made of a retroreflective material.
The path detecting means includes a scanning laser range finder.
You may do so.

Further, the method for controlling an automatic guided vehicle according to the second aspect of the present invention is as follows.
Route detection processing that detects the guide line indicating the traveling route,
Obstacle detection processing to detect obstacles and
Travel control processing that controls the drive means to travel based on the guide line detected in the route detection process, and
When the obstacle is detected by the obstacle detection process, an avoidance amount for avoiding the obstacle is acquired, and if the avoidance amount is within a predetermined avoidable range, the vehicle travels while avoiding the obstacle. Avoidance control processing that controls the driving means and
To be equipped.

In addition, the program according to the third aspect of the present invention is
On the computer
Route detection processing that detects the guide line indicating the travel route,
Obstacle detection processing to detect obstacles,
A travel control process that controls the drive means to travel based on the guide line detected in the route detection process, and a travel control process.
When the obstacle is detected by the obstacle detection process, an avoidance amount for avoiding the obstacle is acquired, and if the avoidance amount is within a predetermined avoidable range, the vehicle travels while avoiding the obstacle. Avoidance control processing that controls the driving means,
To execute.

According to the present invention, obstacles can be avoided without losing sight of the guide line that serves as a mark of the traveling route.

It is a block diagram which shows the functional structure of the automatic guided vehicle which concerns on Embodiment 1. It is a figure which shows the appearance of the automatic guided vehicle which concerns on Embodiment 1. FIG. It is a figure explaining the appearance of the route detection part and the laser which irradiates from the path detection part, which includes the automatic guided vehicle which concerns on Embodiment 1. FIG. FIG. 5 is a view of a route detection unit, an obstacle detection unit, and an operation acquisition unit included in the automatic guided vehicle according to the first embodiment as viewed from the side surface of the automatic guided vehicle. It is a figure explaining the light-receiving intensity when the guide line is detected by the path detection part which concerns on Embodiment 1. FIG. It is a figure which looked at the state which the unmanned guided vehicle which concerns on Embodiment 1 scans the front lower part by the route detection part from the side view. It is the figure which looked at the state which the unmanned guided vehicle which concerns on Embodiment 1 scans the front lower part by the route detection part from above. It is a figure explaining the movement control performed by the automatic guided vehicle which concerns on Embodiment 1 by detecting a guide line. It is a figure explaining the process which the automatic guided vehicle which concerns on Embodiment 1 avoids an obstacle. It is a figure explaining the example when there are a plurality of obstacles. It is a figure explaining how the guide line is branched. It is a flowchart of the movement control process of the automatic guided vehicle which concerns on Embodiment 1. It is a figure which shows an example of the appearance of the automatic guided vehicle which concerns on Embodiment 2. It is a figure explaining the case where the guide line is not installed right above the traveling path. It is a figure which shows the appearance of the automatic guided vehicle which concerns on the modification 1 of Embodiment 2.

Hereinafter, the automatic guided vehicle according to the embodiment of the present invention will be described with reference to figures and tables. The same or corresponding parts in the figure are designated by the same reference numerals.

(Embodiment 1)
The automatic guided vehicle according to the embodiment of the present invention is a device that automatically moves based on a mark (guide line) such as a line indicating a traveling route. FIG. 1 shows an example of the functional configuration of the automatic guided vehicle 100 according to the first embodiment, and FIG. 2 shows an example of the appearance.

As shown in FIG. 1, the automatic guided vehicle 100 includes a control unit 10, a storage unit 20, a route detection unit 31, an obstacle detection unit 32, an operation acquisition unit 33, and a drive unit 40.

The control unit 10 is composed of a CPU (Central Processing Unit) or the like, and by executing a program stored in the storage unit 20, each unit (detection point registration unit 11, misalignment acquisition unit 12, avoidance amount acquisition unit 12) described later is executed. 13. Realize the function of the movement control unit 14). Further, the control unit 10 includes a clock (not shown), and can acquire the current date and time and count the elapsed time. The control unit 10 functions as a control means.

The storage unit 20 is composed of a ROM (Read Only Memory), a RAM (Random Access Memory), and the like, and a part or all of the ROM is composed of an electrically rewritable memory (flash memory, etc.). The ROM stores a program executed by the CPU of the control unit 10 and data necessary for executing the program in advance. Data that is created or changed during program execution is stored in the RAM. The storage unit 20 functions as a storage means. Further, the storage unit 20 includes a detection point history storage unit 21, a position reference point storage unit 22, a passable width storage unit 23, and an avoidable width storage unit 24, which will be described later, as functional configurations.

The route detection unit 31 is composed of a scanning laser range finder or the like as a sensing device, and detects a line (guide line) indicating a traveling route installed below (floor or the like) or the like. As shown in FIG. 3, the path detection unit 31 irradiates the laser 312 from the light emitting unit inside the optical window 311 and reflects the laser on an object (guide line or the like) existing on the floor, wall, ceiling, or the like. Is captured by the light receiving unit inside the optical window 311. The light emitting part (and the light receiving part) rotates 270 degrees (± 135 degrees when the front is 0 degrees) around the rotation axis 313 to irradiate and scan the laser 312 while changing the scan angle, and scan the reflected laser. By processing the captured signal from the light receiving unit, the path detecting unit 31 can measure the distance to the object existing in that direction and the light receiving intensity for each scan angle. In the above, the range of the rotation angle (scan angle) of the light emitting part is set to "± 135 degrees when the front is 0 degrees", and the light emitting part is set to 0 degrees in the direction other than the front, for example ± 90. It may be a specification that rotates by a degree, or may be a specification that rotates by ± 180 degrees.

As shown in FIG. 4, in the route detection unit 31, the rotation axis 313 of the scan is tilted slightly forward from the vertical direction, and the laser 312 is an object (guide line) existing in the front lower part of the automatic guided vehicle 100. Etc.) are to be scanned. The route detection unit 31 functions as a route detection means. The configuration of the path detection unit 31 is not limited to the scanning laser range finder, and may be configured by a camera capable of measuring the distance and the light receiving intensity by the light cast and received, or by another device capable of measuring the distance and the light receiving intensity. It may be configured.

In the present embodiment, the guide line is a line using a retroreflective material, and when a laser beam hits it, the laser beam is reflected in the incident direction. Therefore, the path detection unit 31 can detect the presence of the guide line in the direction of the scan angle when the light receiving intensity is higher than the predetermined reference intensity. The guide line can be laid by applying a paint containing a retroreflective material to the floor or the like, or by attaching an adhesive tape containing the retroreflective material to the floor or the like.

As shown in FIG. 5, the path detection unit 31 can detect the light receiving intensity of the laser reflected from the object existing in that direction while changing the scan angle. Since the light receiving intensity 61 detected at the scan angle in the direction in which the guide line exists is significantly higher than the light receiving intensity 62 detected in the scan angle in the direction in which the guide line does not exist, the path detection unit 31 has the presence of the guide line. The scan angle in the direction to be used can be obtained. Further, since the route detection unit 31 can detect an object other than the guide line and acquire the distance and direction to the object, if an obstacle exists in front of the automatic guided vehicle 100, the obstacle is present. It is possible to acquire information such as the direction in which the vehicle exists, the distance to the obstacle, and how much the obstacle blocks the traveling route.

Returning to FIG. 1, the obstacle detection unit 32 is composed of a scanning laser range finder or the like as a sensing device, similarly to the path detection unit 31. As shown in FIG. 4, the obstacle detection unit 32 has a slightly different mounting position and mounting angle from the path detection unit 31, the rotation axis 323 of the scan is vertical, and the laser 322 is irradiated horizontally forward from the optical window 321. .. As a result, the obstacle detection unit 32 detects an obstacle existing in front of the automatic guided vehicle 100. In addition, the obstacle detection unit 32 not only detects the presence of the obstacle, but also the direction in which the obstacle exists, the distance to the obstacle, the amount of the obstacle protruding into the traveling path (avoidance amount described later), and the like. Information such as the distance between a plurality of obstacles (the width of the space where no obstacles, which will be described later) does not exist can be acquired. The obstacle detection unit 32 functions as an obstacle detection means.

The structure of the obstacle detection unit 32 is not limited to the scanning laser range finder, as in the path detection unit 31, and may be configured by a camera capable of measuring the distance and the light receiving intensity by the light cast / received light. And other devices capable of measuring the light receiving intensity. Further, in the first embodiment, the mounting angle is changed from that of the path detection unit 31, but the mounting angle of the obstacle detection unit 32 is the same as that of the path detection unit 31 (the rotation axis 323 of the scan is slightly forward of the vertical direction). (To lean toward). In this way, the obstacle detection unit 32 can also detect the guide line on the lower front side (floor surface, etc.), the distant guide line is detected by the obstacle detection unit 32, and the closer guide line is detected by the route detection unit. It is also possible to detect with 31 and perform movement control using each information.

Further, the obstacle detection unit 32 and the route detection unit 31 may be shared by one device (scanning laser range finder or the like). In that case, the device is at a higher position (for example, the position of the obstacle detection unit 32 shown in FIG. 4) at an angle in which the rotation axis 313 of the scan is tilted slightly forward above the vertical (for example, in FIG. 4). It is desirable to install it with the inclination of the route detection unit 31 shown). With this installation, the device will be able to scan both obstacles in front and guidelines.

Returning to FIG. 1, the operation acquisition unit 33 is composed of a joystick or the like as an input device, and acquires a user's operation. The operation acquisition unit 33 functions as an operation acquisition means. As shown in FIG. 4, the operation acquisition unit 33 includes a lever 331 and a touch panel 332 integrated with a display panel. Then, the user can instruct the automatic guided vehicle 100 in the direction of tilting the lever 331 and the moving speed by the amount of tilting (tilt angle). Further, the touch panel 332 has an operation menu (setting of maximum speed, acceleration, etc., selection of the set value, movement stop, operation mode (autonomous movement mode, manual movement mode, etc.) as a UI (User Interface) for receiving user's instructions. ) Is displayed, and the user can give each instruction to the automatic guided vehicle 100 by touching them.

Returning to FIG. 1, the drive unit 40 moves the automatic guided vehicle 100 according to an instruction (control) from the control unit 10. The drive unit 40 functions as a drive means. As shown in FIG. 2, the drive unit 40 includes wheels 41 for independent two-wheel drive, a motor 42, and casters 43. The automatic guided vehicle 100 performs parallel movement (translational movement) back and forth by driving the two wheels 41 in the same direction, and rotates on the spot (changes direction) by driving the two wheels 41 in the opposite direction. It is possible to perform turning movement (translation + rotation (direction change) movement) by driving at different speeds. Further, each wheel 41 is provided with a rotary encoder, and the control unit 10 translates by using the rotation speed of the wheel 41 measured by the rotary encoder, the diameter of the wheel 41, the distance between the wheels 41, and the like. The amount of movement and the amount of rotation can be calculated.

For example, if the diameter of the wheel 41 is D and the rotation speed is C, the translational movement amount of the wheel 41 at the ground contact portion is π, DC, and C. If the diameter of the wheel 41 is D, the distance between the wheels 41 is I, the rotation speed of the right wheel 41 is CR, and the rotation speed of the left wheel 41 is CL, the rotation speed of the direction change is (right rotation is positive). Then) 360 ° × D × (CL-CR) / (2 × I). By sequentially adding the translational movement amount and the rotation amount, the drive unit 40 also functions as a mechaometry, and the control unit 10 has its own position (position based on the position and orientation at the start of movement) and Orientation) can be grasped.

A crawler may be provided instead of the wheel 41, or a plurality of (for example, two) legs may be provided and the movement may be performed by walking with the legs. In these cases as well, the position and orientation of the own machine can be measured based on the movements of the two crawlers, the movements of the legs, and the like, as in the case of the wheels 41.

Further, as shown in FIG. 2, the automatic guided vehicle 100 is provided with a loading platform 51, and the transported articles and the like can be mounted on the loading platform 51.

Next, the functional configuration of the control unit 10 of the automatic guided vehicle 100 will be described. As shown in FIG. 1, the control unit 10 realizes the functions of the detection point registration unit 11, the misalignment acquisition unit 12, the avoidance amount acquisition unit 13, and the movement control unit 14, and controls the movement of the automatic guided vehicle 100 and the like. Do.

The detection point registration unit 11 registers the information on the position of the detection point of the guide line detected by the route detection unit 31 in the detection point history storage unit 21. For example, when the guide line extends straight forward from the front of the automatic guided vehicle 100, as shown in FIG. 6, the irradiation angle θ of the laser 312 and the distance D to the object measured by the path detection unit 31 Therefore, the position of the guide line can be obtained as L = D · cos θ ahead of the position of the automatic guided vehicle 100.

Even when the guide line is not in front of the automatic guided vehicle 100, the scan angle φ shown in FIG. 7 (the irradiation direction of the laser 312 defined by ± 135 degrees around the rotation axis 313 with the front direction as 0 degree) From the irradiation angle θ and the distance D shown in FIG. 6, the relative position of the detection point 72 of the guide line 71 by the route detection unit 31 from the automatic guided vehicle 100 can be obtained.

Then, from the position of the automatic guided vehicle 100 obtained by the mechanical function of the drive unit 40 and the relative position of the detection point 72 of the guide line 71 obtained by the route detection unit 31 from the automatic guided vehicle 100, the guide line 71 The position information of the detection point 72 can be obtained. The detection point registration unit 11 registers the position information of the detection point 72 of the guide line 71 thus obtained in the detection point history storage unit 21. As a result, the history 73 of the past detection points is registered in the detection point history storage unit 21.

As described above, in the first embodiment, the scan angle φ of the laser 312 irradiated by the path detection unit 31 is defined as ± 135 degrees around the rotation axis 313, assuming that the front direction is 0 degrees. However, when the absolute value of the scan angle φ becomes a predetermined value (for example, 90 degrees) or more, the direction of the laser 312 turns upward and does not hit the floor surface. Further, even if the direction of the laser 312 is downward, when the absolute value of the scan angle φ becomes a certain level (for example, 60 degrees) or more, the angle with the floor surface becomes too small and the guide line can be detected stably. It will be difficult. Therefore, the automatic guided vehicle 100 sets the detectable width as a range in which the guide line can be stably detected. For example, in FIG. 7, if the guide line can be stably detected between the laser 312s and the laser 312e, the detectable width is W. The width at which the automatic guided vehicle 100 can avoid obstacles to the left or right while detecting the guide line is less than half of this detectable width. Therefore, when the detectable width is 2 m, the avoidable width is set to, for example, 0.9 m.

Returning to FIG. 1, the position deviation acquisition unit 12 acquires the deviation between the current position of the automatic guided vehicle 100 and the position of the past detection point registered in the detection point history storage unit 21 by the detection point registration unit 11. Specifically, as shown in FIG. 8, the distance d between the reference point 75 of the automatic guided vehicle 100 and the point 74 whose front and rear positions are closest to the reference point 75 in the history 73 of the past detection points is acquired. To do. The value of the distance d is a value indicating a deviation from the original position, and by controlling the movement so as to make the value of d as small as possible, the automatic guided vehicle 100 automatically follows the guide line 71. You can move to.

Returning to FIG. 1, the avoidance amount acquisition unit 13 acquires the lateral movement amount required for avoiding the obstacle as the avoidance amount. For example, in FIG. 9, the obstacle 76 protrudes by the width w from the traveling path 77 when moving along the guide line 71. In this case, the avoidance amount acquisition unit 13 acquires the value of the width w as the avoidance amount by using the obstacle detection unit 32. Then, as shown in FIG. 9, the reference point 75 of the automatic guided vehicle 100 is shifted by the avoidance amount w to obtain a new reference point 75'. By shifting the reference point by the avoidance amount and performing the movement control process described later, the travel route of the automatic guided vehicle 100 is changed from the travel route 77 to the avoidance route 78, and the vehicle moves to the position of the automatic guided vehicle 100'. Therefore, the obstacle 76 can be avoided. After passing the obstacle 76, the reference point 75'returns to the original position of the reference point 75, and the traveling route returns to the traveling route 77. In FIG. 9, the traveling route 77 and the avoidance route 78 are shown as strip-shaped routes having a width of a passable width (width + α of the automatic guided vehicle 100) described later.

In FIG. 9, the obstacle 76 exists only on one side (left side), but as shown in FIG. 10, it is possible that an obstacle or a wall also exists on the opposite side (right side). In FIG. 10, an obstacle 76 exists on the left side and an obstacle 76'is present on the right side, and the width x of the space without obstacles between the obstacle 76 and the obstacle 76'can pass through. The case where it is narrower than the width is shown. In this case, the automatic guided vehicle 100 cannot safely pass between obstacles (a space where no obstacles exist), so unless the obstacles are manually removed, the vehicle 100 is in front of the obstacle 76'. I have to stop.

Therefore, the automatic guided vehicle 100 measures the width length (x shown in FIG. 10) of the space where no obstacle exists by using the obstacle detection unit 32 in the movement control process described later, and this value passes through. If it is not wider than possible, it will stop. Further, if the width of the space in which no obstacle exists is equal to or larger than the passable width, the vehicle can travel while avoiding the obstacle 76. Therefore, the automatic guided vehicle 100 avoids the obstacle 76 according to the value of the avoidance amount w.

Returning to FIG. 1, the movement control unit 14 controls the drive unit 40 so that the value (distance d) indicating the position deviation acquired by the position deviation acquisition unit 12 approaches 0. Further, in order to avoid the obstacle described above, the movement control unit 14 avoids or stops the obstacle according to the avoidance amount w for avoiding the obstacle and the width x of the space where the obstacle does not exist. The drive unit 40 is controlled so as to.

Further, the movement control unit 14 can obtain the radius of curvature R in the traveling direction shown in FIG. 8 based on the information of the history 73 of the past detection points registered in the detection point history storage unit 21. Then, the movement control unit 14 can set the translation speed of the automatic guided vehicle 100 based on the radius of curvature R (or the curvature 1 / R). For example, since the centrifugal force acting on the automatic guided vehicle 100 can be calculated from the radius of curvature R and the translational speed, the movement control unit 14 may set the translational speed so that the centrifugal force does not exceed a predetermined value. .. Further, the movement control unit 14 controls the drive unit 40 based on the user instruction when the instruction from the user is acquired by the operation acquisition unit 33.

Next, the functional configuration of the storage unit 20 will be described. The storage unit 20 includes a detection point history storage unit 21, a position reference point storage unit 22, a passable width storage unit 23, and an avoidable width storage unit 24.

The detection point history storage unit 21 stores the information of the history 73 of the detection point 72 of the guide line 71 detected by the route detection unit 31. For example, as shown in FIG. 11, when the guide line 71 is branched, the route detection unit 31 detects a plurality of detection points 72. In this case, all the detected plurality of detection points 72 are registered as detection points. It is stored in the detection point history storage unit 21 by the unit 11.

The position reference point storage unit 22 is based on the reference point 75 of the automatic guided vehicle 100 when the position deviation acquisition unit 12 acquires the position deviation (based on the center point when the automatic guided vehicle 100 is viewed from above). ) The relative position is memorized. For example, in FIG. 8, the reference point 75 is located at the center point of the automatic guided vehicle 100, and in this case, (0,0) is stored in the position reference point storage unit 22.

The passable width storage unit 23 stores a value (for example, 1.1 m) of the width (for example, 1 m) + α (for example, 10 cm) of the automatic guided vehicle 100 as the passable width. If the traveling route is narrowed to less than the passable width due to an obstacle, the automatic guided vehicle 100 will stop.

The avoidable width storage unit 24 has a value (for example, 0.9 m) that is less than half of the maximum width (for example, 2 m, which is the above-mentioned detectable width) that can be detected by the route detection unit 31 as the avoidable width. Will be remembered. If the automatic guided vehicle 100 moves laterally beyond this avoidable width, the route detection unit 31 will not be able to detect the guide line. Therefore, when the automatic guided vehicle 100 detects an obstacle, it avoids the obstacle when the avoidance amount acquired by the avoidance amount acquisition unit 13 is equal to or less than the avoidable width, but avoids the obstacle when it exceeds the avoidable width. It will stop without doing.

Next, the movement control process of the automatic guided vehicle 100 will be described with reference to FIG. When the user instructs the automatic guided vehicle 100 to start autonomous movement, this movement control process is started.

First, the route detection unit 31 scans the front of the automatic guided vehicle 100 in order to detect the guide line indicating the traveling route (step S101). Step S101 is also called a route detection process. Next, the obstacle detection unit 32 scans the front of the automatic guided vehicle 100 in order to detect the presence or absence of an obstacle, the position, and the like (step S102). Step S102 is also called an obstacle detection process. When the route detection unit 31 and the obstacle detection unit 32 are configured by the same device, step S101 and step S102 may be collectively executed by a common scan.

Then, the control unit 10 determines whether or not an obstacle exists within the passable width of the travel path of the automatic guided vehicle 100 based on the scan result by the obstacle detection unit 32 in step S102 (step S103). When it is detected in step S103 that an obstacle exists, the control unit 10 may output an alarm sound or the like to notify the user that the obstacle exists. If an obstacle exists (step S103; Yes), the control unit 10 determines whether or not the distance to the obstacle is less than the threshold value (for example, 1 m) based on the scan result by the obstacle detection unit 32 in step S102. (Step S104). If the distance to the obstacle is equal to or greater than the threshold value (step S104; No), the process proceeds to step S112.

If the distance to the obstacle is less than the threshold value (step S104; Yes), the control unit 10 determines whether or not the automatic guided vehicle 100 can avoid the obstacle (step S105). In this determination, the avoidance amount (the amount of lateral movement required to avoid the obstacle) acquired by the avoidance amount acquisition unit 13 is the avoidable width based on the scan result by the obstacle detection unit 32 in step S102. The width of the space that is less than or equal to the avoidable width stored in the storage unit 24 and has no obstacles in the traveling direction of the automatic guided vehicle 100 is equal to or more than the passable width stored in the passable width storage unit 23. If, it is determined that the obstacle can be avoided, and if not, it is determined that it cannot be avoided.

If avoidance is possible (step S105; Yes), the avoidance amount acquisition unit 13 stores the acquired avoidance amount as an avoidance value in the storage unit 20, and stores the position reference point stored in the position reference point storage unit 22 as an avoidance value. It shifts only (step S106) and proceeds to step S112. Step S106 is also called avoidance control processing. If the avoidance value is already stored in the storage unit 20 in step S106, the avoidance amount acquisition unit 13 stores the position reference point stored in the position reference point storage unit 22 (stored in the storage unit 20). Return to the original value (using the previous avoidance value, etc.), then store a new avoidance value (which is the avoidance amount acquired this time) in the storage unit 20, and shift the position reference point by the new avoidance value. It is stored in the reference point storage unit 22.

If it is not unavoidable (step S105; No), the movement control unit 14 controls the drive unit 40 to stop the traveling of the automatic guided vehicle 100 (step S107). In step S107, the control unit 10 may output an alarm sound (a sound different from the alarm sound at the time of obstacle detection) or the like to notify the user that the traveling has been stopped. Then, the control unit 10 determines whether or not the user's operation has been acquired from the operation acquisition unit 33 (step S108). If the user's operation is not acquired (step S108; No), the process proceeds to step S110.

When the user's operation is acquired (step S108; Yes), the movement control unit 14 controls the drive unit 40 according to the user operation acquired from the operation acquisition unit 33 (step S109). Then, the control unit 10 determines whether or not an obstacle exists within the passable width of the automatic guided vehicle 100 in the traveling direction by the obstacle detection unit 32 (step S110). If there is an obstacle (step S110; Yes), the process returns to step S107. If there are no obstacles (step S110; No), the process returns to step S101.

On the other hand, if there is no obstacle in the traveling direction of the automatic guided vehicle 100 (step S103; No), the control unit 10 erases the avoidance value stored in the storage unit 20 (step S111). Erasing the avoidance value is a process of returning the position reference point deviated by the avoidance value to the original position and writing it in the position reference point storage unit 22, and then setting the avoidance value to 0 and writing it in the storage unit 20.

Next, the control unit 10 determines whether or not the route detection unit 31 has detected the guide line (step S112). If the guide line is not detected (step S112; No), the process proceeds to step S107. When the guide line is detected (step S112; Yes), the detection point registration unit 11 registers the information on the position of the detection point of the guide line detected by the route detection unit 31 in the detection point history storage unit 21 (step S113). .. As shown in FIG. 11, when the guide line 71 is branched, the route detection unit 31 detects a plurality of detection points 72, and the detection point registration unit 11 detects the plurality of detection points, as described above. All 72 are registered in the detection point history storage unit 21.

Then, the misalignment acquisition unit 12 is registered in the detection point history storage unit 21 by the current position of the automatic guided vehicle 100 (the position of the reference point 75 stored in the position reference point storage unit 22) and the detection point registration unit 11. The deviation from the position of the past detection point that has been performed is acquired (step S114). When the guide line 71 is branched, the misalignment acquisition unit 12 acquires the deviation from the current position of the automatic guided vehicle 100 for each of the plurality of detection points 72 by the route detection unit 31. In this case, in the next step S115, the control unit 10 may ask the user to instruct the user in which direction of the plurality of detection points 72 to proceed by the operation acquisition unit 33.

Then, the control unit 10 acquires the user's operation by the operation acquisition unit 33 (step S115). If there is no particular user operation, the control unit 10 proceeds to step S116 without doing anything in step S115. Examples of the user's operation acquired in step S115 include the end of movement control, the setting of the relative position of the reference point 75 stored in the position reference point storage unit 22, and the direct operation instruction (stop, forward, backward) of the drive unit 40. , Rotation, etc.) and the like.

Then, the control unit 10 determines whether or not to end the movement control (step S116). For example, when the user gives an instruction to end the movement control to the operation acquisition unit 33 in step S115, the movement control is ended. If the movement control is finished (step S116; Yes), the movement control process is finished.

If the movement control is not terminated (step S116; No), the movement control unit 14 drives the automatic guided vehicle 100 so that the value indicating the position deviation acquired by the position deviation acquisition unit 12 approaches 0. The unit 40 is controlled (step S117), and the process returns to step S101. Step S117 is also called a travel control process. When the user receives a direct operation instruction of the drive unit 40 in step S115, the movement control unit 14 controls the drive unit 40 according to the content of the direct operation instruction in step S117.

Further, when the guide line 71 is branched, the misalignment acquisition unit 12 acquires a plurality of values indicating the misalignment, but when the user is requested to instruct in which direction to proceed in step S115, In step S117, the movement control unit 14 controls the drive unit 40 so that the deviation between the detection point corresponding to the direction instructed by the user and the position of the automatic guided vehicle approaches 0.

Further, instead of asking the user's instruction every time when the guide line 71 is branched, the movement control unit 14 is a drive unit so that the Nth smallest value among the plurality of misalignment values approaches 0. A rule such as "controlling 40" and a value of N may be set in advance. If N is set to 1 here, the automatic guided vehicle 100 will select the traveling route that can be traced most smoothly among the plurality of branches of the guide line 71. In the case where such a rule and the value of N are set, if the number of branches is smaller than N, the largest value among the plurality of misalignment values is moved so as to approach 0. The control unit 14 controls the drive unit 40.

The movement control process of the automatic guided vehicle 100 has been described above. However, the above-mentioned movement control process (shown in FIG. 12) is an example of the movement control process, and if the movement control is performed to avoid obstacles without losing sight of the guide line, the content and order of the processes are changed. You may.

As described above, in the automatic guided vehicle 100, the obstacle detection unit 32 scans the obstacle and performs avoidance control when it can be avoided. Therefore, the automatic guided vehicle 100 can move while avoiding obstacles without losing sight of the guide line. Further, since the avoidance control is performed after the distance to the obstacle becomes less than the threshold value, even if the obstacle is detected, the user immediately moves the obstacle to a place other than the movement route of the automatic guided vehicle 100. Therefore, the automatic guided vehicle 100 can perform normal traveling along the guide line without moving to avoid the obstacle.

(Embodiment 2)
The automatic guided vehicle 100 according to the first embodiment was able to detect the guide line installed in the front lower part (for example, the floor) by the route detection unit 31 and move along the guide line. However, the guide line does not necessarily have to be installed on the floor or the like, and may be installed on the ceiling, for example. Here, as the second embodiment, the automatic guided vehicle 101 in which the guide line installed in the front upper part (for example, the ceiling) is detected by the route detection unit 31 will be described.

The functional configuration of the automatic guided vehicle 101 according to the second embodiment is the same as the functional configuration of the automatic guided vehicle 100 according to the first embodiment, but as shown in FIG. 13, the scanning direction by the route detection unit 31 is forward and upward. It has become. As a result, the route detection unit 31 according to the second embodiment can detect guide lines (marks such as lines indicating the traveling route) installed in the front upper part (ceiling, wall, etc.). The movement control process of the automatic guided vehicle 101 is the same as the movement control process of the automatic guided vehicle 101 (FIG. 12).

The automatic guided vehicle 101 automatically moves based on the position of the guide line installed above (for example, the ceiling), but when the ceiling is high, the guide line should be installed directly above the original traveling route. It may be difficult. Even in such a case, the travel route is set by installing a guide line on the wall, wall, shelf, etc. of the ceiling, or by hanging a rope-shaped guide wire from the ceiling, instead of directly above the original travel route. be able to.

An example of this is shown in FIG. In the example shown in FIG. 14, the travel path 79 of the automatic guided vehicle 101 is not directly below the guide line 71. Therefore, the reference point 75 is set at a position shifted from the center point of the automatic guided vehicle 101 by the difference between the position where the guide line 71 is projected on the floor and the position of the traveling path 79. For example, when the value of this deviation is S in the lateral direction (X direction), (S, 0) is stored in the position reference point storage unit 22. By setting the reference point 75 in this way, the installation location of the guide line 71 is not limited to directly above the traveling path 79, and can be flexibly set.

However, in the first embodiment, the avoidable width storage unit 24 stores the avoidable width common to the left and right (a value less than half of the detectable width (for example, 2 m) (for example, 0.9 m)), but in the second embodiment, , The normal detection position of the guide line 71 is not always the center of the detectable width. Therefore, in the second embodiment, the avoidable width storage unit 24 stores the avoidable widths on each of the left and right sides. For example, in the example of FIG. 14, when the detectable width is 2 m and the position where the guide line 71 is projected on the floor is shifted to the right by 0.7 m from the traveling path 79, the right avoidable width is 1.6 m (= 0). .9m + 0.7m), the left avoidable width is stored as 0.2m (= 0.9m-0.7m).

However, also in the second embodiment, if the path detection unit 31 is attached so that the front direction of the laser 312 faces the guide line 71, the normal detection position of the guide line 71 becomes the center of the detectable width. When the route detection unit 31 is attached to the automatic guided vehicle 101 in this way, the avoidable width storage unit 24 may store the avoidable width (for example, 0.9 m) common to the left and right as in the first embodiment. .. On the contrary, in the first embodiment, when the detectable width of the route detecting unit 31 is asymmetrical, the avoidable width storage unit 24 may store the avoidable widths of the left and right sides respectively.

In the automatic guided vehicle 101 according to the second embodiment, since the route detection unit 31 scans the front upper part to detect the traveling route, it serves as a mark of the traveling route upward such as the ceiling instead of the floor surface which is relatively easily deteriorated. Guide lines can be installed. Therefore, the automatic guided vehicle 101 can not only avoid obstacles without losing sight of the guide line, but also improve the maintainability of the guide line, which is a mark of the traveling route.

Since the distance between the automatic guided vehicle 101 and the ceiling is usually longer than the distance between the automatic guided vehicle 101 and the floor surface, the avoidable width stored in the avoidable width storage unit 24 is the first embodiment. There is a high possibility that the width will be larger than the avoidable width of the automatic guided vehicle 100. Also, if the guide line is installed on the floor, the guide line cannot be detected if an obstacle is placed on the guide line, but if the guide line is installed on the ceiling, the guide line will be There is almost no worry of hiding in obstacles. Therefore, as compared with the automatic guided vehicle 100 according to the first embodiment, the automatic guided vehicle 101 can avoid obstacles more flexibly.

(Modification 1 of Embodiment 2)
The automatic guided vehicle 101 can move automatically when the route detection unit 31 detects the guide line on the front upper side. However, if the front upper part of the route detection unit 31 is shielded by a transported article or the like, the automatic guided vehicle 101 cannot detect the guide line by the route detection unit 31, and automatic movement becomes impossible. Therefore, as shown in FIG. 15, the automatic guided vehicle 102 according to the first modification of the second embodiment is provided with a plate 52 for preventing the upper part of the route detection unit 31 from being shielded by the conveyed article or the like. By providing the plate 52, the automatic guided vehicle 102 can stably detect the traveling route and the like without the laser being blocked by the transported article and the like.

(Modification 2 of Embodiment 2)
In the above-described second embodiment, the misalignment acquisition unit 12 is registered in the detection point history storage unit 21 by the position of the reference point 75 stored in the position reference point storage unit 22 and the detection point registration unit 11. The automatic guided vehicles 101 and 102 are placed directly below the guide line 71 by acquiring the deviation from the position of the past detection point and controlling the drive unit 40 by the movement control unit 14 so as to bring this displacement closer to 0. It is possible to move on a travel route other than. However, the mechanism that enables the automatic guided vehicles 101 and 102 to move on a traveling route other than directly below the guide line 71 is not limited to this.

For example, the movement control unit 14 controls the drive unit 40 so that the scan angle φ at which the guide line 71 is detected becomes a predetermined reference angle (for example, φ ₀ is registered in the storage unit 20). It may be. In order to perform such control, the scan angle when the detection point registration unit 11 detects the detection point 72 of the guide line 71 in the detection point history storage unit 21 in step S113 of the movement control process (FIG. 12). φ is also registered, and in step S117, the movement control unit 14 drives the movement control unit 14 so that the difference between the past scan angle φ registered in the detection point history storage unit 21 and the reference angle φ ₀ approaches 0. The unit 40 may be controlled.

The functions of the automatic guided vehicles 100, 101, and 102 can also be performed by a computer such as a normal PC (Personal Computer). Specifically, in the above embodiment, it has been described that the program of the movement control process performed by the automatic guided vehicles 100, 101, 102 is stored in the ROM of the storage unit 20 in advance. However, the program can be stored in a flexible disk, a CD-ROM (Compact Disk Read Only Memory), a DVD (Digital Versaille Disc), an MO (Magnet-Optical Disc), a memory card, a USB (Universal Serial Bus) memory, or the like. A computer capable of realizing each of the above-mentioned functions may be configured by storing and distributing the program in a recording medium, reading the program into a computer, and installing the program. Further, a computer capable of realizing each of the above functions may be configured by distributing the program via a communication network such as the Internet, reading the program into a computer, and installing the program.

Although the preferred embodiment of the present invention has been described above, the present invention is not limited to the specific embodiment, and the present invention includes the invention described in the claims and the equivalent range thereof. Is done.

10 ... Control unit, 11 ... Detection point registration unit, 12 ... Position deviation acquisition unit, 13 ... Avoidance amount acquisition unit, 14 ... Movement control unit, 20 ... Storage unit, 21 ... Detection point history storage unit, 22 ... Position reference point Storage unit, 23 ... Passable width storage unit, 24 ... Avoidable width storage unit, 31 ... Path detection unit, 32 ... Obstacle detection unit, 33 ... Operation acquisition unit, 40 ... Drive unit, 41 ... Wheels, 42 ... Motor , 43 ... Caster, 51 ... Loading platform, 52 ... Plate, 61, 62 ... Light receiving intensity, 71 ... Guide line, 72 ... Detection point, 73 ... History, 74 ... Point, 75, 75'... Reference point, 76, 76' ... Obstacles, 77,79 ... Travel route, 78 ... Avoidance route, 100,100', 101,102 ... Automatic guided vehicle, 311,321 ... Optical window, 312,312s, 312e, 322 ... Laser, 313,323 ... Rotating shaft, 331 ... lever, 332 ... touch panel

Claims (6)

An automatic guided vehicle equipped with a drive means and a control means.
A route detecting means for detecting a guide line indicating a traveling route, and
Obstacle detection means for detecting obstacles,
With more
The control means
The driving means is controlled so as to travel based on the guide line detected by the route detecting means.
When the obstacle detecting means detects the obstacle, an avoidance amount for avoiding the obstacle is acquired, and if the avoidance amount is within a predetermined avoidable range, the vehicle travels while avoiding the obstacle. Control the driving means,
Automated guided vehicle. The control means
When the obstacle detecting means detects the obstacle, the width of the space where the obstacle does not exist is acquired in the traveling direction, and if the width is equal to or larger than a predetermined passable width, the vehicle travels while avoiding the obstacle. To control the driving means,
The automatic guided vehicle according to claim 1. The route detecting means detects the guide line by scanning the front upper part of the automatic guided vehicle.
The automatic guided vehicle according to claim 1 or 2. The guide line is made of a retroreflective material.
The path detecting means includes a scanning laser range finder.
The automatic guided vehicle according to any one of claims 1 to 3. Route detection processing that detects the guide line indicating the traveling route,
Obstacle detection processing to detect obstacles and
Travel control processing that controls the drive means to travel based on the guide line detected in the route detection process, and
When the obstacle is detected by the obstacle detection process, an avoidance amount for avoiding the obstacle is acquired, and if the avoidance amount is within a predetermined avoidable range, the vehicle travels while avoiding the obstacle. Avoidance control processing that controls the driving means and
A method of controlling an automatic guided vehicle. On the computer
Route detection processing that detects the guide line indicating the travel route,
Obstacle detection processing to detect obstacles,
A travel control process that controls the drive means to travel based on the guide line detected in the route detection process, and a travel control process.
When the obstacle is detected by the obstacle detection process, an avoidance amount for avoiding the obstacle is acquired, and if the avoidance amount is within a predetermined avoidable range, the vehicle travels while avoiding the obstacle. Avoidance control processing that controls the driving means,
A program to execute.

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