JP2015210656A - Automated mobile device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an automated mobile device having an automatic guided vehicle capable of selecting an appropriate traveling line to travel even if traveling lines are provided so as to intersect each other.SOLUTION: At a position where two traveling lines intersect each other, one traveling line 10 is provided so as to be parted across the other traveling line 10. A PC 9 of an AGV 2 detects angles and a median value of the traveling line 10 in an image captured by a camera 5, and calculates an evaluation value for each traveling line 10 on the basis of the angles and the median value detected this time and those detected last time to select a traveling line 10 having the smallest evaluation value.

Description

  The present invention relates to an automatic movement apparatus having an automatic traveling vehicle that travels along a traveling line provided on a road surface.

  In an automatic traveling vehicle such as an automatic guided vehicle that automatically travels along a guide course, a traveling line serving as a guide is provided on the course, and automatic traveling is performed by detecting the traveling line by the automatic guided vehicle or the like. As a method for detecting a travel line, a method of recognizing an image by photographing with a camera (see, for example, Patent Document 1), or a method of detecting a travel line with a magnetic tape and detecting with a magnetic sensor provided in an automatic guided vehicle (for example, Patent Document 2) is known.

  Depending on the setting of the course on which the above-described automatic guided vehicle or the like travels, there are cases where two travel lines are crossed. In this case, in the method for recognizing an image by photographing with a camera as described in Patent Document 1, depending on the intersecting angle, it is unclear which of the detected two travel lines is correct, There was a case where the vehicle traveled outside the travel line that should be traveled.

  In the method of detecting with a magnetic sensor as described in Patent Document 2, a command tape or the like for setting the magnetic sensor to a non-detection mode is provided before the cross point, and the cross point goes straight without operating the magnetic sensor. Running. In this method, it takes time to provide a command tape before the cross point.

  Further, in the case of a magnetic sensor, it is possible to travel at a cross point by not recognizing the magnetic tape when all of the plurality of mounted magnetic sensors are ON. In this case, if the two traveling lines that cross each other are not orthogonal to each other, all the magnetic sensors are not turned on, so that the traveling cross course is limited to be orthogonal.

  The present invention aims to solve such problems.

  That is, an object of the present invention is to provide an automatic moving apparatus having an automatic traveling vehicle that can travel by selecting an appropriate traveling line even when the traveling lines are provided so as to intersect.

  In order to solve the above-described problems, the invention described in claim 1 recognizes a travel line provided on a road surface, an image capturing unit for capturing the travel line, and an image captured by the image capturing unit. An automatic traveling apparatus having an image recognition means and an automatic traveling vehicle traveling along the travel line recognized by the image recognition means, wherein the travel line is at a position where the two travel lines intersect, One traveling line is provided so as to be divided across the other traveling line, and the automatic traveling vehicle is configured such that the image recognition unit includes an angle and a center of the traveling line in an image photographed by the photographing unit. The position is detected, and an evaluation value is calculated for each travel line based on the angle and center position of the travel line detected this time and the angle and center position of the travel line detected last time. The evaluation value is Selecting the traveling line that matches a predetermined condition defined because as the travel line in a position that the intersection, it is an automatic movement device according to claim.

  According to the present invention, when the travel lines intersect by providing the other travel line in a divided manner and selecting a travel line in which the evaluation value calculated by the automatic traveling vehicle matches a predetermined condition. However, it is possible to travel by selecting an appropriate travel line.

It is explanatory drawing which shows the outline | summary of the automatic movement apparatus concerning one Embodiment of this invention. It is an example of the course which the automatic guided vehicle shown by FIG. 1 drive | works. It is an example of the outline which PC detected by FIG. 1 detected. It is an example of the image image | photographed when the right steering is too much. It is an example of the input screen displayed on PC shown in FIG. It is explanatory drawing of a process at the time of misdetecting the dirt on a road surface. It is explanatory drawing of the process in the case of a cross course. It is a flowchart of operation | movement of the automatic guided vehicle shown by FIG. It is a flowchart of operation | movement of the automatic guided vehicle shown by FIG. It is a flowchart of operation | movement of the automatic guided vehicle shown by FIG.

  Hereinafter, an embodiment of the present invention will be described with reference to FIGS.

  As shown in FIG. 1, an automatic movement apparatus 1 according to an embodiment of the present invention includes an automatic guided vehicle (AGV) 2 as an automatic traveling vehicle and a traveling line 10.

  The AGV 2 automatically travels along the travel line 10 that has been image-recognized. The AGV 2 includes a vehicle body 3, a main battery 4, a camera 5, an illumination 6, a DC12V-AC100V converter 7, and a personal computer (PC) 9.

  The vehicle body 3 supports a base plate (not shown) on which the main battery 4, camera 5, illumination 6, DC12V-AC100V converter 7, and PC 9 are arranged, and supports the base plate and covers a resilient material for absorbing shock at the time of collision. A pipe frame (not shown), which is also a protective fence, and a pulling arm (not shown) connected to a carriage to which the AGV 2 pulls, and the like.

  The main battery 4 supplies electric power for operating a motor (not shown) that rotates the wheels, the PC 9, and the like. The main battery 4 is disposed on a base plate of the vehicle body 3 with a storage battery housed in a case, for example.

  The camera 5 is photographing means for photographing the road surface immediately before the vehicle body 3. The camera 5 is composed of, for example, a USB (Universal Serial Bus) camera and a polarizing lens. The polarizing lens is attached in front of the lens of the USB camera, and can block the surface reflected light (reflecting light) of the road surface and the travel line 10 and suppress halation and highlight on the photographing screen. The camera 5 is connected to the USB terminal of the PC 9. Accordingly, an image taken by the camera 5 is input to the PC 9. In addition, the camera 5 in the present embodiment is installed with a road surface angle θ of the visual field center line of 35 degrees, and the visual field range is a range of 10 to 40 cm in front of the vehicle body 3 and a width of 40 cm.

  The illumination 6 illuminates a position where the visual field center line of the camera 5 intersects the road surface. The light source of the illumination 6 is a fluorescent lamp, for example.

  The DC12V-AC100V converter 7 converts the DC 12V voltage supplied from the main battery 4 into AC 100V.

  The PC 9 is, for example, a notebook PC, and has a mother board, a hard disk drive, a display, a keyboard, a USB interface, and the like on which a CPU (Central Processing Unit) is mounted, as is well known. Then, the CPU reads and executes the program stored in the hard disk drive.

  The travel line 10 is made of, for example, black vinyl tape. In the present embodiment, the traveling line 10 is captured by the camera 5 as described above, and thus may not be a magnetic tape. Further, the color of the travel line 10 may be changed as appropriate according to the color of the road surface, the sensitivity of the camera 5, and the like.

  The PC 9 of the present embodiment recognizes the travel line 10 on the road surface from the image taken by the camera 5, generates an operation control command for traveling along the recognized travel line 10, and controls the motor and the like described above. Give it to the microcomputer. That is, the PC 9 functions as an image recognition unit that recognizes an image captured by the camera 5 (imaging unit). Further, the PC 9 detects the road surface code sign, decodes the operation instruction associated with the code sign, generates an operation control instruction corresponding to the operation instruction, and gives it to the microcomputer or the like.

  Next, the recognition process of the travel line 10 based on the image acquired from the camera 5 in the automatic movement apparatus 1 having the above-described configuration will be described with reference to FIGS.

  FIG. 2 is an example of a course layout. In FIG. 2, AGV2 moves in the direction of the arrow (from left to right in the figure). The address indicates a point where the AGV 2 needs to decode the operation instruction, such as a loading point or an unloading point. For example, the vinyl tape is separated by a predetermined distance to the right of the traveling direction of the main line. By providing only (for example, 20 cm), it is used as a code sign indicating an address.

  The PC 9 acquires an image (horizontal 160 dots, vertical 120 dots) obtained by the camera 5 capturing the above-described visual field range, and extracts an outline of the travel line 10 in the image using an image processing library executed on the PC 9. To detect (recognize).

  Next, the contour area, median (center position) and angle (inclination angle with respect to the vertical axis of the screen) are calculated. For example, as shown in FIG. 3, it is assumed that the contour is composed of seven line segments. If x is the horizontal direction and y is the vertical direction, the coordinates of each line segment are (75, 10), (69, 59), (76, 88), (72, 106), (84, 8), (86 , 85) and (80, 115).

At this time, the horizontal median (median x) and the vertical median (median y) are
Median x = (x maximum value + x minimum value + 1) / 2 = (86 + 69 + 1) / 2 = 78,
Median y = (y maximum value + y minimum value + 1) / 2 = (115 + 8 + 1) / 2 = 62,
("/" Indicates division).

The angle is
Angle = atan ((y maximum value−y minimum value + 1) / (x maximum value−x minimum value + 1))
= Atan ((115-8 + 1) / (86-69 + 1)) ≈81 degrees
(Atan indicates arctangent).

The angle is 90-81 = 9 degrees because the angle is based on 0 degree. The angle must also reflect the left and right orientations,
If y <y when x takes the minimum value <y when x takes the maximum value)
If y ≧ y when x takes the minimum value ≧ y when x takes the maximum value, the right direction (+ sign),
Then, in the case of FIG. 3, since y = 59 when x takes the minimum value and y = 85 when x takes the maximum value, the angle = −9 degrees (leftward 9 degrees).

  As the area, the area obtained by the image processing library is used as it is. As a result, the median is calculated as (78, 62), the angle is −9, and the area is 1500.

Here, if the vinyl tape used as the running line 10 has a commercially available 19 mm width, as an effective tape (running line) contour condition, an area with an area of 950 (19 mm × 50 mm) to 5700 (19 mm × 300 mm) is used. Limit to. That is, an outline having an area of 950 to 5700 mm ² is effective. This is in order to prevent the contamination is detected floor erroneous contour, 950 mm ² smaller than the contour is not considered tape contour, means that the contour of more than 5,700 mm ² nor considered tape contour.

  In addition, the effective tape length (about 30 cm) which can be image | photographed with the camera 5 can be varied by changing the range of the area to restrict | limit. This merit is that the vehicle can run even if a part of the image of the tape portion is missing due to tape contamination or the like. In this embodiment, the tape length is set to an area of about 10 cm.

Next, the operating condition of AGV2 is determined as follows from the calculated median and angle.
If the median x-coordinate value is 60 ≦ x ≦ 100, go straight. Left steering if x <60. Steer right if 100 <x.
If the angle is less than ± 20 degrees, go straight. Steer left if more than -20 degrees. Steer right if +20 degrees or more.
The final steering direction is determined from the correlation between the median and the angle.

  For example, as in the case of “too much right steering” shown in FIG. 4, if the final steering is determined only by the angle (45 degrees), the right steering is continued and the travel line 10 disappears from the camera view. In such a case, the median value is adopted and left steering is performed. That is, the final steering direction is determined based on the correlation between the median and the angle so that the tape contour always comes near the center of the camera screen. This is the same control as when a person drives a car.

  Next, when the AGV 1 travels along the travel line 10, refer to FIG. 2 and FIGS. 4 to 7 for an operation that travels (straightly travels) correctly even when the road surface is dirty or the travel line 10 intersects. explain.

  First, when a standby screen as shown in FIG. 5A is displayed on the display of the PC 9, the user inputs a destination from the keyboard of the PC 9 (FIG. 5B). FIG. 5B shows a case where 1 is input as the destination station (address). Then, when the user presses a start key assigned to the keyboard of the PC 9 (start key), the vehicle starts running. In the following description, the departure is assumed to be the start point in FIG. 2 (immediately after the address 10).

  When the AGV 2 travels on the course of FIG. 2, a travel line erroneously detected due to dirt on the road surface appears at the position indicated by A. An image photographed at that time is shown in FIG. FIG. 6A shows the actual travel line 10 and dirt. When traveling in the direction of the arrow in FIG. 6A, the outline of the travel line 10 is initially recognized as shown in FIG. 6B. Here, in FIG. 6B, it is assumed that the angle = 0 degrees and the median value = (80, 60).

  When the AGV 2 continues to travel, dirt is recognized in addition to the travel line 10 as shown in FIG. Here, in FIG. 6C, the left contour (dirt) in the image has an angle = −40 degrees and the median value = (60, 30), and the central contour (running line 10) has an angle = 0. Degree, median = (80, 60), and right contour (dirt) is angle = 40 degrees and median = (120, 60).

When a plurality of contours are recognized as shown in FIG. 6C, an evaluation value is calculated based on the angle and the median value. The evaluation value calculation formula (evaluation formula) in this embodiment is:
Absolute value of (the angle of the immediately preceding contour−the angle of the detected contour) + the absolute value of (the median value of the immediately preceding contour x−the median value of the detected contour x) + (the median value y of the immediately preceding contour−the median value y of the detected contour) Absolute value,
The contour having the smallest value calculated by this evaluation formula is selected as the travel line 10 to be traveled.

  Here, the immediately preceding contour indicates FIG. 6B in the case of FIG. FIG. 6B is taken at the timing immediately before the timing at which FIG. 6C is photographed, and is, for example, an image photographed 30 cm before FIG. 6C. Note that the shooting timing of the camera 5 is not limited to every 30 cm. For example, a shorter distance interval or a longer distance interval may be used. Alternatively, the time interval may be set instead of the distance interval.

  Further, it is not limited to the photographing timing, and at least the timing of the contour detection, the angle, the median, and the area calculation processing may be used. For example, FIG. 6B illustrates a case where the image is subjected to contour detection, angle, median, and area calculation processing immediately before FIG. 6C. For example, when the camera 5 is capturing a moving image, contour detection and angle, median, and area calculation processing are performed at predetermined frame intervals.

The evaluation values in FIG.
The left contour is | 0 − (− 40) | + | (80−60) | + | (60−30) | = 90,
The central contour is | 0-0 | + | (80-80) | + | (60-60) | = 0,
The right contour is | 0− (40) | + | (80−120) | + | (60−60) | = 80,
It becomes. Since the calculated evaluation value is selected as the travel line 10 that should travel along the contour having the smallest evaluation value, the center contour is selected as the travel line 10.

  When a plurality of contours are detected at the next photographing timing, the central contour angle and median value selected by the evaluation based on the evaluation formula may be treated as the immediately preceding contour.

  Next, when AGV2 reaches the position indicated by B beyond the position indicated by A in FIG. 2, a location where two traveling lines 10 intersect (cross) appears. In such a place where two traveling lines 10 cross (also referred to as a cross course), one traveling line 10 is divided across the other traveling line 10 as shown in FIGS. It is provided to be. In the present embodiment, the divided interval is 8 cm, but may be appropriately changed according to the width of the vinyl tape.

  FIG. 7A shows an actual cross course. When traveling in the direction of the arrow in FIG. 7A, the outline of the traveling line 10 is initially recognized as shown in FIG. 7B. Here, in FIG. 7B, it is assumed that the angle = 0 degrees and the median value = (80, 60).

  When the AGV 2 continues to travel, a cross course is recognized as shown in FIG. Here, in FIG. 7C, the upper contour in the image has an angle = 0 degrees and a median value = (80, 20), and the central contour has an angle = 90 degrees and a median value = (80, 60). ), And the lower contour has an angle = 0 degree and a median value = (80, 105).

  Also in the case of the cross course, the evaluation value of each contour is calculated based on the same evaluation formula as that in the case of the stain shown in FIG. 6, and the contour having the smallest evaluation value is selected as the travel line 10 to be traveled.

The evaluation values in FIG.
The upper contour is | 0-0 | + | (80-80) | + | (60-20) | = 40,
The central contour is | 0−90 | + | (80−80) | + | (60−60) | = 90,
The lower profile is | 0-0 | + | (80-80) | + | (60-105) | = 45,
It becomes. Since the calculated evaluation value is selected as the travel line 10 that should travel along the contour having the smallest evaluation value, the upper contour is selected as the travel line 10.

  That is, the angle and the median value (center position) of the travel line 10 in the image captured by the camera 5 (imaging means) are detected. Then, an evaluation value is calculated for each travel line 10 based on the angle and median value (center position) of the travel line 10 detected this time and the angle and median value (center position) of the travel line 10 detected last time. The travel line 10 that meets the condition that the calculated evaluation value is a predetermined minimum is selected as a travel line at a position where the travel line 10 intersects.

  In FIG. 7, the two travel lines 10 are orthogonal to each other. However, the present invention is not limited to this, and the other travel lines 10 may be divided and provided at other angles, and appropriate using the above evaluation formula. The travel line 10 can be selected.

  In the above-described evaluation formula, the detection contour (current detection value) is subtracted from the immediately previous contour (previous detection value). However, for example, the ratio of both may be obtained. Further, the predetermined condition is not limited to the minimum, and a condition for selecting the optimum travel line such as maximum and minimum may be set in accordance with the arithmetic expression.

  Next, the operation of AGV2 is shown in the flowcharts of FIGS. This flowchart operates on the PC 9. First, a station number input screen is displayed on the display of the PC 9 (step S1), and when the key indicating start is pressed (Yes in step S2), the running of the AGV 2 is started.

  Next, an image taken from the camera 5 is acquired (step S3), the contour of the travel line 10 is detected (step S4), and the median, angle, and area are calculated for each detected contour (step S5). ).

  Next, it is determined whether the numerical mark Flag is ON or OFF (step S6). The numerical mark Flag is a flag that is turned ON when a numerical mark is detected in the subsequent step S10, and a value indicating ON or OFF is held in a memory or the like in the PC 9.

If the numbered flag Flag is OFF, it is determined whether or not the travel line 10 has been found (step S7). Traveling line 10 as described above, the area is determined by whether there is a 950 mm ² or more 5,700 mm ² or less of the contour.

When the travel line 10 is found (when Step S7 is Yes), it is determined whether there are two or more contours (Step S8). In other words, the area is 950 mm ² or more 5,700 mm ² or less of the contour to determine whether or not there are a plurality of.

  When there are two or more contours (when Step S8 is Yes), it is determined whether or not the two contours form an angle within 20 degrees (Step S9). That is, referring to the angles of the two contours, it is determined whether the angles are included within 20 degrees. For example, if one is 0 degrees and the other is 15 degrees, this step is Yes. If there are three or more contours, it may be determined as Yes if there is a combination of contours that meets this condition.

  When the two contours form an angle of 20 degrees or less (when Step S9 is Yes), it is determined whether or not a numerical mark is detected (Step S10). The numbered mark indicates a code sign indicating that the above-described address is present. When a numerical mark is detected (when Step S10 is Yes), the numerical mark Flag is set to ON (Step S11).

  When a numerical mark is not detected (when Step S10 is No), it is determined whether there are a plurality of contours (Step S12). In this step, as with step S8, the travel line 10 found in step S7 is determined.

  When there are a plurality of contours (when Step S12 is Yes), the travel line 10 closest to the previously acquired contour is selected as the main line (Step S13). In this step, the evaluation is performed using the above-described evaluation formula, and the contour having the smallest evaluation value is determined as the travel line closest to the previously acquired contour (immediate contour), and is selected as the main line.

  Next, a travel command (straight, left steering, right steering) is determined from the median value and angle of the main line contour. As described above, this is determined by the correlation between the median and the angle.

  On the other hand, if the numerical mark Flag is ON in step S6, it is determined whether or not the numerical mark is lost (step S21). The disappearance of the numbered mark indicates that the AGV 2 has traveled and passed the code sign indicating the numbered mark.

  Next, when there is no numbered mark (Yes), the numbered mark detection flag is set to OFF (step S22), and a prescribed operation in the DRIVE_PLAN file is executed (step S23). The DRIVE_PLAN file is a file stored in advance in the PC 9 by a wireless LAN (Local Area Network) or a memory card before traveling, and actions (actions) to be performed at stations (addresses) on the route are sequentially set in the order of the traveling route. Scheduled operation schedule is included.

  Next, it is determined whether the action to be executed in step S23 is “T” (step S24), and if it is “T” (in the case of Yes), AGV2 is stopped (step S25). That is, the action “T” means an operation for stopping the AGV 2. After stopping, when the start key is pressed in step S2, the running is resumed.

  If no travel line is found in step S7 (in the case of No), it is determined whether contour detection has failed three times in succession (step S31). Since this step is executed when the travel line 10 is not found, if this step is executed three times in succession, the contour detection has failed three times in succession.

  If the contour detection fails three times in succession, the AGV 2 is stopped and a display indicating course out is displayed on the display of the PC 9 (step S32).

  According to the present embodiment, at the position where two traveling lines intersect, one traveling line 10 is provided so as to be divided across the other traveling line 10. The PC 9 of the AGV 2 detects the angle and median of the travel line 10 in the image taken by the camera 5 and evaluates each travel line 10 based on the angle and median detected this time and the angle and median detected last time. The value is calculated, and the travel line 10 having the minimum value is selected.

  By doing so, since the other running line 10 is divided, the contours of the intersecting portions are all substantially linear, and the angle of the contour can be easily obtained from the line segments constituting the contour. .

  In addition, the travel value detected last time is calculated by calculating the evaluation value for each travel line 10 based on the angle and median value detected this time and the previously detected angle and median value, and selecting the travel line 10 having the minimum value. A contour having a median or angle closest to the line 10 can be selected. Therefore, it is possible to travel on an appropriate travel line in the intended direction even when the travel lines intersect.

  Further, since the angle is detected from the image photographed by the camera 5, a magnetic sensor and a magnetic tape are not required, and the angle at which the traveling lines intersect is not limited to being orthogonal (right angle).

In addition, you may weight the evaluation formula of embodiment mentioned above. For example,
Absolute value of (angle of the immediately preceding contour−angle of the detected contour) × coefficient A +
(The absolute value of (median value x of the immediately preceding contour−median value x of the detected contour) +
(The absolute value of the median value y of the immediately preceding contour-the median value y of the detected contour)) x coefficient B,
Thus, if the coefficient A and the coefficient B are appropriately set, it is possible to select whether to give priority to the angle or to give priority to the median value. Note that only one of the coefficient A and the coefficient B may be set.

  The present invention is not limited to the above embodiment. That is, those skilled in the art can implement various modifications in accordance with conventionally known knowledge without departing from the scope of the present invention. Of course, such modifications are included in the scope of the present invention as long as the configuration of the automatic movement apparatus of the present invention is provided.

1 Automatic movement device 2 Automated guided vehicle (automatic traveling vehicle)
5 Camera (photographing means)
9 PC (image recognition means)
10 Travel line

JP-A-3-201110 JP-A-5-333926

Claims (2)

Traveling along the travel line recognized by the image recognition means having a travel line provided on the road surface, an image capturing means for capturing the travel line, and an image recognition means for recognizing an image captured by the image capturing means An automatic traveling device having an automatic traveling vehicle,
The travel line is
At the position where the two traveling lines intersect, one traveling line is provided so as to be divided across the other traveling line,
The autonomous vehicle is
The image recognition means detects the angle and center position of the travel line in the image captured by the photographing means, and the angle and center position of the travel line detected this time and the angle of the travel line detected last time And an evaluation value is calculated for each travel line based on the center position, and the travel line in which the calculated evaluation value matches a predetermined condition is selected as a travel line at the intersecting position.
An automatic moving device characterized by that.   The automatic movement apparatus according to claim 1, wherein the image recognition unit calculates the evaluation value by weighting at least one of the angle and the central position.

Images