JP2000276228A - Control method of unmanned mobile cart - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enable unmanned traveling to the instructed destination while avoiding an obstacle on a passage even without installing a marker for guide on a moving path or even in an environment having a crossing or the dead end of a road. SOLUTION: The traveling and steering of a dolly are controlled by a program for sensor for detecting and avoiding the obstacle and compensating the parallelism of a car body to the passage on the basis of outputs from plural sensors for sensing the peripheral part of the car body of the dolly, a program for image for recognizing the crossing or corner of the passage based on the images in the advancing direction of the dolly provided from plural cameras 2a and 2b provided on the dolly and a main program for determining the advancing direction and controlling a traveling speed or steering quantity corresponding to the operated results of both the above programs. This control is performed while considering the output results of sensors and the processing results of images from the cameras 2a and 2b.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for controlling an unmanned mobile vehicle that moves unattended to a destination in a facility such as a factory, office, hospital, or welfare facility.

[0002]

2. Description of the Related Art The traveling and steering control of an unmanned mobile vehicle is conventionally performed by processing signals from a plurality of sensors for sensing the periphery of the vehicle (for example, see Japanese Unexamined Patent Application Publication No.
And Japanese Patent Application Laid-Open No. Hei 5-462, for example, based on image processing from a camera provided on a cart.
No. 40) is provided.

In the former case, for example, sensors such as ultrasonic sensors are attached to the front, rear, left and right of a bogie, and the front and rear sensors detect obstacles, and the left and right sensors detect parallelism of the vehicle body to a passage. Running and steering are performed based on the detection result.

In the latter case, a bogie is followed by detecting a guidance marker at an intersection or a corner from a captured image.

[0005]

By the way, it is possible to detect an obstacle by using a sensor. However, in an environment where there is an intersection or a dead end in a moving path, it is necessary to distinguish the obstacle from the obstacle. Is difficult.

[0006] Further, it is difficult to detect any unknown obstacle existing on the passage by using the image processing, and when using a marker for guidance, the marker must be set in advance. .

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and it is an object of the present invention to eliminate the necessity of providing a guide marker on a moving path, and furthermore, to provide a passageway even in an environment where there is an intersection or a dead end. An object of the present invention is to provide a control method of an unmanned mobile vehicle that can perform unmanned traveling to a designated destination while avoiding an obstacle on the upper side.

[0008]

SUMMARY OF THE INVENTION The present invention is directed to detecting and avoiding an obstacle based on outputs from a plurality of sensors provided on a trolley for sensing the periphery of the trolley body, and parallelizing the vehicle with a passage. A program for sensor that performs degree compensation, a program for image that recognizes intersections and corners of passages based on images of the traveling direction of the carriage obtained from a plurality of cameras provided on the carriage, and the calculation results of both programs It is characterized in that the traveling steering of the bogie is controlled by a main program for determining the traveling direction and controlling the traveling speed and the amount of steering according to the main program. The control is performed in consideration of the output result of the sensor and the processing result of the image by the camera.

The image program may recognize an intersection or a T-junction by detecting a break in the boundary line with the wall indicating the path end. In particular, the image program may be configured to recognize the boundary line with the wall indicating the path end. The main program performs the measurement of the distance to the break at the same time as the detection of the break, and the main program discriminates the obstacle from the T-junction or the intersection by checking the output result of the sensor program corresponding to the break. It is preferable to keep it. Further, it is preferable that the avoidance operation at the time of obstacle detection is performed based on the result of image processing performed by the image program.

The image program may recognize a corner or a dead end by detecting a boundary line with a wall indicating a passage end in a horizontal direction of the image.

When the passage crosses approximately 90 ° vertically and horizontally, entry into the intersection of the passage or the like is detected when the sensor on the side of the vehicle does not detect a wall in the sensor program, and processing in the image program is performed. It is good to match with a result, or to detect the approach to a passage from an intersection etc. at the time of detecting a wall with a sensor on the side of a car body in a sensor program, and to match with a processing result in an image program.

In the sensor program, when detecting the wall by the sensor on the side of the vehicle body, the presence or absence of a passage at the side of the bogie is determined when the state of the distance to the wall is maintained at or above a threshold value for determination of presence or absence for a predetermined time or more. Is preferred.

Further, the presence or absence of a wall at the time of forward movement is determined based on the outputs of sensors mounted on both sides near the front of the bogie body, and based on the outputs of the sensors mounted on both sides near the rear of the bogie body. It is good to judge the wall at the time of retreat.

When the passages cross each other at approximately 90 ° in the vertical and horizontal directions, in both the sensor program and the image program, the route to the destination is changed depending on the presence or absence of left and right walls at the intersection or T-junction. It is good to memorize it.

Further, in the image processing performed by the image program, it is preferable to calculate a position where a boundary line with a wall indicating a passage end or an extension thereof intersects in the image to detect a direction of the vehicle body with respect to the passage. In particular, it is preferable to determine the steering amount of the bogie on the condition that the orientation of the vehicle body with respect to the passage detected by the image program and the orientation of the vehicle body with respect to the passage obtained by the sensor program match.

When there is a sudden change in the distance to the wall detected by the sensor program, the operation of compensating the parallelism of the vehicle body by the sensor program may be omitted.

It is preferable that the main program is executed by an upper computer located above the computer that executes the sensor program and the image program, and that the power capacity of the upper computer is larger than the power capacity of the lower computer.

It is also preferable to mutually confirm normal operation between the upper computer and the lower computer.

A control device for executing a program includes a wireless communication device for wireless communication with an external management computer,
It is also preferable that the management computer can monitor the control device and transmit a command to the control device.

[0020]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described in detail with reference to an example of an embodiment. FIG. 1 shows the configuration of an unmanned mobile vehicle used in the present invention. Drive motors 4 for the left and right drive wheels
The bogie which includes the vehicle motor 4 and travels and steers by operating the drive motors 4 and 4 is provided with a non-contact type distance detecting sensor 1a, such as an infrared sensor or an ultrasonic sensor, at the front and rear and right and left of the vehicle body, respectively. 1b, 1c, and 1d, it is possible to detect obstacles on the front and rear sides, left and right sides, and walls along the moving path.

The bogie body has a pair of left and right cameras 2a and 2b facing forward as imaging means, and the image processing device 8 to which the cameras 2a and 2b are connected performs distance measurement by stereo vision. It is something that can be done. The cameras 2a and 2b are installed on the camera rotation mechanism 3 and can change their directions, so that an image in the traveling direction can be obtained even when the vehicle retreats.

A control device 6 for controlling the driving of the drive motors 4 and 4 and the camera rotation mechanism 3 is constituted by a microcomputer, and is connected to the cameras 2a and 2b via the image processing device 8. A / D
The respective sensors 1a, 1b, 1c, 1d are also connected via the converter 7, and furthermore, the encoder 5 attached to the drive motor 4 is connected. This encoder 5
Is for measuring the traveling distance.

Based on the information obtained through the image processing device 8, the information obtained from the sensors 1 a, 1 b, 1 c, 1 d, and the mileage information obtained through the encoder 5, the control device 6 controls the traveling of the bogie. The control for steering is performed. In the control device 6, the sensors 1a, 1b, 1c,
A sensor program for avoiding obstacles and compensating for the degree of parallelism with respect to the path of a bogie based on a signal from 1d;
a) an image program for recognizing a passage or an intersection based on images obtained from a and 2b, and a main program for determining a traveling direction such as a right / left turn based on a calculation result of the two programs. Then, the traveling speed and the amount of steering are determined to control the movement of the bogie. The control device 6 also counts the pulse signal from the encoder 5 and converts it into a travel distance.

Next, the processing performed in the control device 6 will be described. As shown in FIG. 2 (a), when there is an intersection 10 or a T-junction 11 in the traveling direction of the bogie 1, as a result of processing an image from the camera (see FIG. The part A where the boundary line is broken is recognized. The controller 6 determines that there is an intersection 10 when the interrupted portion a is on both the left and right, and that there is a T-junction 11 when it is on only one side.
Can be detected.

However, even if there is an obstacle 12 at the end of the passage as shown in FIG. 3, the boundary line with the wall may be interrupted and recognized as a T-junction 11 in the image program. . For this purpose, the signal of the sensor 1a or 1b attached to the traveling direction side of the bogie body is processed by a sensor program, and when an obstacle 12 is detected, the interrupted portion is identified as not an intersection or a T-junction. If the obstacle 12 is not detected, it is identified as an intersection or the like.

If it is determined that the portion where the boundary line with the wall is interrupted is due to the obstacle 12, it is necessary to perform an avoidance operation. At this time, as shown in FIG. 4, when the left boundary line is interrupted, the avoidance operation is performed on the right side, and when the right boundary line is interrupted, the avoidance operation is performed on the left side. It is possible to prevent the person from being stuck and forced to retreat.

As shown in FIGS. 5 (a) and 6 (a),
When there is a corner 13 or a dead end 14 in the traveling direction of the bogie, as a result of processing the image from the camera by the image program, the boundary line with the wall is recognized in the horizontal direction.
When both the left and right borders are interrupted by the border recognized in the horizontal direction as shown in (b), it is a dead end 14 and the border recognized in the horizontal direction as shown in FIG. 5 (b). When only one boundary line is interrupted by the line, it can be recognized that the corner 13 is bent to the other one side.

In an environment where the passages of the trolley cross approximately 90 ° vertically and horizontally, when the trolley enters the intersection 10, FIG.
As shown in (a), left and right sensors 1c,
1d is in a state where there is no reaction of the wall, and this is detected by the sensor program. On the other hand, since the image program processes the images from the cameras 2a and 2b before approaching the intersection, the intersection 10 is recognized and the distance is measured. , The approach to the intersection 10 is reliably detected.

When the vehicle enters the passage from the intersection 10, as shown in FIG. 7 (b), the reaction of the wall can be obtained by the left and right sensors 1c and 1d. Then, by comparing the processing result of the image program with the traveling distance, entry into the passage is reliably detected. A similar approach can be used to detect entry into a T-junction or entry into a corner.

When the approach to an intersection or the like is detected by the left and right sensors 1c and 1d, the presence or absence of the reaction of the wall obtained by the sensors 1c and 1d is maintained in the same state for a predetermined time T as shown in FIG. It is determined whether or not. Thereby, it is possible to prevent noise n from being mixed and erroneous detection due to a bar-shaped obstacle such as a desk leg.

In addition to the sensors 1c and 1d on the sides of the bogie body, sensors 1c and 1d are provided on both sides of the front side and the rear side, respectively.
As shown in FIG. 9, when the sensors d, 1e, and 1f are attached and the front sensors 1c and 1d detect the approach to the intersection and the like during the retreat operation, the front sensors 1c and 1d detect the approach to the intersection. It is possible to detect an approach to an intersection or the like at a stage.

Further, as described above, the passage is substantially 90 °.
In an environment where the vehicle crosses vertically and horizontally, the approach to the intersection is detected by the above-described method, and the object from the departure point 15 through the corner 17, the intersection 18, and the T-junction 19 as shown in FIG. The route to the ground 16 can be stored by replacing the sensor 1c on the left and the sensor 1d on the right with a change in the presence or absence of a wall reaction shown in FIG. 10B.

By the way, as a result of processing the images from the cameras 2a and 2b by the image program, the boundary line (or an extension thereof) with the wall indicating the left passage end is defined as the boundary line with the wall indicating the right passage end. By determining the position where the line (or an extension thereof) intersects on the screen, the approximate direction of the bogie relative to the passage can be detected. As shown in FIG. 11, when inclined to the right, the intersecting position is shifted to the left, and when inclined to the left, the reverse is true.

Further, in the sensor program, the output change of the left and right sensors 1c and 1d during running is monitored, and the steering amount is controlled so as to compensate for the parallelism with respect to the passage of the vehicle body. As shown in FIG. 12, only when the direction of the bogie body with respect to the passage detected by the sensor program substantially matches the direction detected by the image program, the steering amount is controlled so as to compensate for the result. I do. As a result, correct parallelism with respect to the passage of the bogie is maintained.

On the other hand, when the truck goes straight ahead at the intersection of the passage, the sensors 1c and 1d on the side of the truck do not react to the wall, so that the steering amount is controlled based on the processing result of the sensor program. Unintentional bogie operation. Therefore,
As shown in FIG. 13, when there is a sudden change in the reaction of the sensors 1c and 1d on the side of the bogie, this is prevented by canceling the parallelism compensation of the vehicle body to the passage in the sensor program.

As shown in FIG. 14, the control device 6 is separated into an upper computer 61 and a lower computer 62, and the sensor program and the image program are turned right and left by the lower computer 62 in accordance with the calculation results. For example, the main program for determining the traveling direction is executed by the upper computer 61, and the capacity of the power supply 63 for supplying power to the upper computer 61 is made larger than the capacity of the power supply 64 for supplying power to the lower computer 62. Keep it. As a result, the stability of the upper computer 61 can be made higher than the stability of the lower computer 62, and runaway of the bogie due to an incorrect instruction can be prevented. Further, by confirming the normal operation between the upper computer 61 and the lower computer 62, the security can be further improved.

In addition, by enabling the control device 6 to communicate with a management computer or the like equipped with a wireless communication device, the management computer can grasp the abnormality of the bogie and the current position and provide the instruction purpose. It is possible to change the land.

[0038]

As described above, according to the present invention, the detection and avoidance of obstacles and the detection of the vehicle body with respect to the passage are performed based on outputs from a plurality of sensors provided on the vehicle and sensing the periphery of the vehicle body. A program for a sensor that performs parallelism compensation, a program for an image that recognizes intersections and corners of a passage based on images of the traveling direction of the carriage obtained from a plurality of cameras provided on the carriage, and calculation of both programs The main program that determines the traveling direction and controls the traveling speed and the amount of steering according to the result controls the traveling of the bogie, taking into account the output result of the sensor and the processing result of the image by the camera. In addition to this, there is no need to install guidance markers on the moving path, and even in an environment where there is an intersection or a dead end, avoid obstacles on the aisle and avoid It is possible to carry out the running.

If the image program recognizes an intersection or a T-junction by detecting a break in the boundary line with the wall indicating the path end, the intersection or the T-junction can be reliably detected.

In particular, the image program detects a break in the boundary line with the wall indicating the end of the passage and measures the distance to the break at the same time as the main program. The main program determines the output result of the sensor program corresponding to the break and the result. By matching
By distinguishing a T-junction or an intersection from an obstacle, detection of an obstacle and a T-junction or an intersection is not hindered.

Further, when the avoidance operation at the time of detecting an obstacle is performed based on the result of the image processing performed by the image program, the certainty of avoiding the obstacle is improved.

If the image program recognizes a corner or a dead end by detecting a boundary line with a wall indicating a passage end in the horizontal direction of the image, the corner or the dead end can be reliably detected.

In the case where the passage crosses approximately 90 ° vertically and horizontally, when the sensor side program stops detecting the wall with the sensor on the side of the vehicle body, the approach to the intersection of the passage is detected, and the processing in the image program is performed. By collating with the result, it is possible to easily and reliably detect an approach to an intersection or the like.

When the sensor program detects a wall detected by a sensor on the side of the vehicle body, the approach to the passage from the intersection or the like is detected and collated with the processing result in the image program so that the approach to the passage from the intersection or the like is detected. Detection can be performed accurately.

In detecting the wall by the sensor on the side of the vehicle body in the sensor program, the presence or absence of a passage on the side of the bogie is determined when the distance to the wall is maintained at or above a threshold value for determining the presence or absence for a predetermined time or more. By doing so, the reliability of detection of entry into an intersection or the like or entry into a passage from an intersection or the like is improved.

Also, the presence or absence of a wall at the time of forward movement is determined based on the outputs of sensors mounted on both sides near the front of the bogie body, and based on the outputs of sensors mounted on both sides near the rear of the bogie body. If the wall at the time of retreat is determined, entry into an intersection or the like or entry into a passage can be detected earlier, and the steering operation can be facilitated when the vehicle turns at an intersection.

When the passages intersect vertically and horizontally at approximately 90 °, the route to the destination is changed in the presence of the right and left walls at the intersection or T-junction in both the sensor program and the image program. It is good to memorize it. The route information to the destination and the configuration of the bogie main body can be simplified.

Further, in the image processing performed by the image program, the position of the vehicle body with respect to the passage is detected by calculating the position where the boundary line with the wall indicating the passage end or the extension line thereof intersects in the image. It is preferable in terms of improving the straight running stability, and in particular, the steering amount of the bogie is determined on the condition that the orientation of the vehicle body with respect to the path detected by the image program and the direction of the vehicle body with respect to the path obtained by the sensor program are matched. Thus, the certainty of reaching the destination can be increased.

When there is a sudden change in the distance to the wall detected by the sensor program, the operation of compensating the parallelism of the vehicle body by the sensor program may be omitted. Also in this case, the certainty of reaching the destination can be increased.

If the main program is executed by an upper computer located above the computer that executes the sensor program and the image program, and the power capacity of the upper computer is made larger than the power capacity of the lower computer, the security is improved. Can be improved.

By mutually confirming the normal operation between the upper computer and the lower computer, the security can be improved.

A control device for executing a program includes a wireless communication device for wireless communication with an external management computer,
It is also preferable that the management computer can monitor the control device and transmit a command to the control device. Usability can be improved.

[Brief description of the drawings]

FIG. 1 is a block circuit diagram of an example of an embodiment of the present invention.

FIG. 2 is an explanatory diagram of an operation at an intersection and a T-junction according to the first embodiment.

FIG. 3 is an explanatory diagram illustrating an operation of detecting an obstacle according to the first embodiment;

FIG. 4 is an operation flowchart for obstacle avoidance according to the first embodiment;

FIG. 5 is an operation explanatory diagram in a corner portion of the above.

FIG. 6 is an explanatory diagram of an operation in a dead end of the above.

FIG. 7 is an explanatory diagram of an operation at the same intersection.

FIG. 8 is a time chart relating to noise countermeasures in detecting an intersection according to the first embodiment.

FIG. 9 is another operation explanatory diagram of the same intersection.

FIG. 10 is an explanatory diagram relating to route storage according to the first embodiment.

FIG. 11 is a diagram illustrating detection of the vehicle body parallelism by the image processing according to the first embodiment.

FIG. 12 is a flowchart for determining a steering amount according to the embodiment.

FIG. 13 is another flowchart of the steering amount determination according to the first embodiment.

FIG. 14 is a block circuit diagram of another example.

[Explanation of symbols]

 1a, 1b, 1c, 1d Sensor 2a, 2b Camera 4 Drive motor 5 Motor encoder 6 Controller

 ────────────────────────────────────────────────── ─── Continuing on the front page (72) Inventor Koichi Mitani 1048, Kazuma Kadoma, Kadoma City, Osaka Prefecture F-term in Matsushita Electric Works, Ltd. DC08 5H301 AA02 AA10 BB05 CC03 CC06 CC08 DD01 DD17 GG01 GG09 GG10 GG12 GG23 GG24 GG28 GG29 KK03 LL01

Claims (16)

[Claims] A sensor program for detecting and avoiding obstacles and compensating for parallelism of a vehicle body with a passage based on outputs from a plurality of sensors provided on the vehicle and sensing the periphery of the vehicle body of the vehicle. An image program for recognizing intersections, corners, etc. of passages based on images of the traveling direction of the carriage obtained from a plurality of cameras provided on the carriage, and determining the traveling direction according to the calculation results of both programs. A method for controlling an unmanned mobile trolley, wherein the trolley controls the traveling of the trolley with a main program for controlling the running speed and the steering amount. 2. The control method for an unmanned mobile vehicle according to claim 1, wherein the image program recognizes an intersection or a T-shaped intersection by detecting a break in a boundary line with a wall indicating a path end. 3. The image program detects a break in a boundary line with a wall indicating a passage end and simultaneously measures a distance to the break, and a main program outputs an output result of a sensor program corresponding to the break. And T
3. The control method for an unmanned mobile trolley according to claim 1 or 2, wherein a road or an intersection and an obstacle are identified. 4. The control method for an unmanned mobile trolley according to claim 1, wherein the avoidance operation at the time of detecting an obstacle is performed based on a result of image processing performed by the image program. 5. The control method for an unmanned mobile vehicle according to claim 1, wherein the image program recognizes a corner or a dead end by detecting a boundary line with a wall indicating a passage end in a horizontal direction of the image. . 6. When the passage crosses approximately 90 ° vertically and horizontally, the sensor program detects an approach to an intersection or the like of the passage when the sensor on the side of the vehicle body does not detect a wall, and an image program. The control method for an unmanned mobile trolley according to claim 1, wherein the comparison is performed with the processing result in (1). 7. When a passage crosses approximately 90 ° vertically and horizontally, the sensor program detects entry into the passage from an intersection or the like when a wall of the vehicle body is detected by a sensor on the side of the vehicle body, and performs processing in the image program. The control method for an unmanned mobile trolley according to claim 1, wherein the result is compared with a result. 8. In the sensor program, when detecting a wall by a sensor on the side of the vehicle body, the presence or absence of a passage on the side of the bogie is determined when a state where the distance to the wall is equal to or greater than a threshold value for determination of presence or absence is maintained for a predetermined time or more. The control method for an unmanned mobile trolley according to claim 1, wherein the determination is performed. And determining whether there is a wall at the time of forward movement based on outputs of sensors attached to both sides near the front of the bogie body,
8. The control method for an unmanned mobile trolley according to claim 1, wherein the determination of the wall at the time of retreat is performed based on outputs of sensors attached to both sides near the rear of the trolley body. 10. When the passages cross each other at approximately 90 ° vertically and horizontally, in both the sensor program and the image program, the route to the destination is determined by the presence or absence of the intersection or the right and left walls at the T-shaped intersection. 8. The control method for an unmanned mobile trolley according to claim 1, wherein the state change is stored. 11. An image processing performed by an image program, wherein a position at which a boundary line with a wall indicating an end of a passage or an extension thereof intersects on an image is detected, and a direction of a vehicle body relative to a passage is detected. The control method for an unmanned mobile trolley according to claim 1. 12. The amount of steering of the bogie is determined on the condition that the direction of the vehicle body with respect to the path detected by the image program and the direction of the vehicle body with respect to the path obtained by the sensor program match. 12. The method for controlling an unmanned mobile trolley according to claim 11. 13. The method according to claim 1, wherein when the distance to the wall detected by the sensor program changes abruptly, the parallelism compensation operation of the vehicle body by the sensor program is cut off. 13. The method for controlling an unmanned mobile trolley according to claim 12. 14. The computer according to claim 1, wherein the main program is executed by an upper computer located above the computer executing the sensor program and the image program, and the power capacity of the upper computer is made larger than the power capacity of the lower computer. The control method for an unmanned mobile cart according to any one of claims 1 to 13. 15. The control method for an unmanned mobile trolley according to claim 14, wherein a normal operation is mutually confirmed between the upper computer and the lower computer. 16. A control device for executing a program includes a wireless communication device for wireless communication with an external management computer, and the management computer can monitor the control device and transmit a command to the control device. The control method for an unmanned mobile trolley according to claim 1.