JPH0943353A - Automated guided vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To detect the existence of an obstacle by transmitting ultrasonic waves and making use of the reflected waves from the obstacle by means of the obstacle existence judging means in an automated guided vehicle. SOLUTION: The interference beam 6 of the fellow laser beams is brought into existence ahead of the course at all times by means of laser beam applicators 2 and 2', and its light emitting color is recognized by the image processing of a video camera 3. Since the interference beam 6 does not come into being when an obstacle exists, it can not recognize the light emitting color, so the existence of the obstacle becomes the standard of judgment. This device can be constituted at low cost, and also this can make the recognition which does not care about the physical property of the obstacle.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an automated guided vehicle for automatically carrying luggage in a factory or the like, and more particularly to an automated guided vehicle capable of identifying obstacles.

[0002]

2. Description of the Related Art In relatively large-scale factories and the like, an unmanned guided vehicle is increasingly used to transport materials and luggage in the factory. The automated guided vehicle automatically transports luggage and materials by setting a transportation route in advance by a built-in computer. There is an advantage that it is possible to easily carry things such as large-sized materials and luggage that are troublesome for human beings to carry, and to reduce labor costs because they are unmanned.

However, there have been problems such as personal injury to workers by unmanned guided vehicles, and there are several types of unmanned guided vehicles equipped with a function of detecting the presence or absence of obstacles on the path in order to solve such problems. Proposed. For example,
Signals such as ultrasonic waves or infrared rays are always transmitted forward in the path, and if there is an obstacle, the signal is reflected by the obstacle, and the reflected wave is received to determine the presence or absence of the obstacle. There are a type of judgment, and a type of discrimination from the shape of an obstacle by a CCD camera and its image processing.

[0004]

However, the type utilizing the reflected wave lacks the accuracy of identifying the obstacle because the intensity of the reflected wave varies depending on the shape, color, material, etc. of the obstacle. There was a problem. For example, infrared rays do not reflect black. In addition, when the signal transmission device fails and the signal is not transmitted, the reflected wave does not occur even if there is an obstacle, so that it cannot be recognized.

Further, in the method of identifying the obstacle from the shape of the CCD camera, it is difficult to identify the obstacle unless the processing speed of the computer used for the image processing is considerably high, and the cost of the apparatus becomes very expensive. There was a problem. The present invention has been made in view of the above problems, and an object of the present invention is to provide an automatic guided vehicle that can accurately identify an obstacle at low cost regardless of its shape, color, material, or the like.

[0006]

According to the present invention, at least two laser light irradiating means each of which irradiation direction can be arbitrarily set and which constantly irradiate laser light in mutually intersecting directions, There is provided an automatic guided vehicle characterized by comprising an image processing means for taking in image information of laser light emitted from the laser light irradiation means.
Here, the laser beam irradiation means is a device that projects a strong directional light beam, a so-called laser beam, with a strong single wavelength obtained by irradiating a crystal such as an artificial ruby with strong light and stimulating the crystal. Say It is preferable to provide at least one of the laser light irradiation means with a scanning control means for automatically scanning the irradiation direction. As the scanning means,
Applicable may be one that operates a mirror that reflects laser light at high speed, one that bends the direction of laser light by a magnetic force used in a television, or a well-known drive mechanism including a motor and a gear.

[0007]

In the automatic guided vehicle of the present invention, the irradiation direction of the laser light irradiating means is set so that the respective laser beams are always crossed at an appropriate point in front of the route, and the front side of the route is always irradiated by the laser beam. To do. By overlapping each laser light in the intersection of the laser light, another laser light having a different wavelength from the laser light emitted from the laser light irradiation means, that is, interference light is generated,
This interference light shows a different emission color from the laser light emitted from the laser light irradiation means due to the difference in its wavelength. here,
If there is an obstacle in front of the route, one of the laser beams is reflected by the obstacle, so that there is no intersection of the laser beams and no interference light is generated. Therefore, the data of the luminescent color emitted by the interference light, and in some cases the position data thereof are also stored in the image processing means, and the presence or absence of the luminescent color is identified by the image processing means and used as a criterion for the presence or absence of an obstacle. To do. In the case where the laser light irradiation means is provided with the scanning control means, the laser light can be scanned while being synchronized with each other, so that the intersection of the laser lights can be moved.

[0008]

[Examples]
A preferred embodiment of the present invention will be described with reference to the accompanying drawings.

FIG. 1 is a schematic diagram of an automated guided vehicle of the present invention. The automatic guided vehicle 1 shows the main body thereof, and the configuration of the drive system for traveling is the same as the conventional one. A laser beam irradiation device 2 is provided in the front part of the automatic guided vehicle 1, and a rotation mechanism 4 is provided so that each can arbitrarily set the irradiation direction. In this embodiment, two of them are provided above and below. The rotating mechanism 4 is composed of a well-known hinge component, for example, a ball joint or the like, and the direction of the laser light irradiation device 2 can be manually set and fixed manually. The video camera 3 is integrated with an image processing device (not shown) to form an image processing means.
The video camera 3 is directed toward the front of the route and constantly photographs the interference light of the laser light emitted from the laser light irradiation device, and transmits the image signal as an electric signal to the image processing device. It should be noted that the video camera 3 may have a filter attached to its lens that allows only a predetermined color to pass through. The filter also makes it possible to identify a variety of colors including those that cannot be identified by humans. The image processing device itself has a computer, and identifies the presence or absence of laser interference light from the image signal sent from the video camera 3.

FIG. 2 shows a block diagram of a control system of the automatic guided vehicle 1 of this embodiment.

The host computer controls the respective devices and controls them, and the control procedure of the transport path and the respective devices is programmed in advance. As a specific action, normally, the drive device is controlled so that the automatic guided vehicle 1 travels on a preset transportation path, and if the obstacle is recognized by the image processing device, the traveling is stopped. Commands such as sounding an alarm can be issued. Also,
It is possible to select whether or not to irradiate the laser beam and to issue an operation command to the scanning control device described later.

Next, a method of recognizing an obstacle will be described with reference to model diagrams 3 and 4. It should be noted that (a) of the figure shows the operating condition of the automatic guided vehicle 1, and (b) shows the image recognized by the video camera 3. This aspect is the same in other figures. FIG. 3 shows a state where there is no obstacle. In addition,
The left side of the figure is the traveling direction of the automated guided vehicle 1. The lower laser light irradiation device 2'irradiates the laser light 5'in the traveling direction parallel to the ground, and the upper laser light irradiation device 2 intersects the laser light 5 ', that is, the laser light obliquely downward. By irradiating light 5, the interference light 6 is generated. The position where the laser beams intersect can be set arbitrarily by adjusting the rotating mechanism 4 provided in the laser beam irradiation device 2. Therefore, in consideration of expected obstacle features, the forward direction of the automated guided vehicle 1 is considered. The appropriate position can be selected.

In the situation where there is no obstacle as shown in FIG. 3, the video camera 3 photographs at least the interference light 6, but FIG. 3B shows the situation where the interference light 6 is photographed. The same applies to the other drawings below. Here, the emission color of the interference light 6 is different from that of the laser lights 5 and 5 '. This is because the laser light is a wave, and when the laser light is crossed, the laser light overlaps with each other to generate light having different wavelengths. The image processing device linked with the video camera 3 is programmed so that the emission color of the laser light can be identified, and the emission color of the interference light 6 is input in advance to determine whether the interference light 6 exists. To the host computer.

Next, the operation when an obstacle exists will be described with reference to FIG. For example, when a human 7 appears in the traveling direction of the automatic guided vehicle 1, at least one of the laser beams 5 ′ collides with the human 7 and is blocked, so that the laser beam 5,
The 5'companies do not cross each other and the interference light 6 does not occur. Therefore, the interference light 6 does not appear in the camera image (b) either.
At this time, the image processing apparatus identifies that the interference light 6 has disappeared from the presence or absence of the emission color, and notifies the host computer that an obstacle exists. In response to this, the host computer sequentially executes the program when the obstacle is present. For example, the driving device may be stopped to stop the conveyance, and an alarm is sounded.

When the obstacle is eliminated, the interference light 6 is generated again and the conveyance is continued. Even if the laser light irradiation device 2 or 2'fails, the interference light 6 does not occur, so it can be used as a fail-safe device. In this way, since the obstacle is recognized based on the presence or absence of the interference light, the accurate identification can be performed regardless of the physical property of the obstacle.

Next, another embodiment of the laser light irradiation method will be described with reference to FIGS. The method of identifying the obstacle is the same as the above-mentioned example. FIG.
In this case, the upper laser light irradiation device 2 is additionally installed and the interference light 6 is generated at three places on the laser light 5 ′. As the interference light 6 is increased, the obstacle identification range is expanded, and even a special obstacle such as a falling object or a high-speed moving object can be identified quickly.

6 to 8 show a mode in which a scanning control device (not shown) is provided in the laser beam irradiation device 2 to scan the laser beam. The scanning control device is controlled by a host computer according to a preset program, and changes the irradiation direction of each laser light irradiation device at a high speed while synchronizing with each other, and utilizes the bending of the laser light by the magnetic force used in the television. A device is preferred. In each of the following embodiments, one laser light irradiation device is provided on each of the upper and lower sides.

In the embodiment of FIG. 6, only the laser beam 5 is scanned forward and backward along the laser beam 5'at a high speed. According to this method, it is possible to obtain the same effect as that of the embodiment shown in FIG. 5 without adding a laser light irradiation device. The obstacle identification area is one-dimensional (line). In the embodiment shown in FIG. 7, the laser beam 5 ′ further below the embodiment shown in FIG.
Is a mode in which the left and right are scanned at high speed. In order to constantly generate the interference light 6, the upper laser light 5 is scanned forward and backward at high speed, and at the same time, it is scanned left and right at high speed in synchronization with the movement of the lower laser light 5 '. Since the obstacle identification area is two-dimensional (flat), it is possible to identify a wide area without adding a laser light irradiation device.

The mode of FIG. 8 is a mode in which the laser beam 5'below the mode of FIG. 7 is scanned at high speed in the vertical direction. The laser beams 5 and 5 ′ are synchronized with each other while generating the interference beam 6 and are scanned at high speed vertically and horizontally or forward and backward and left and right. Therefore, the interference light scans through the air at high speed, and the obstacle identification area in this case is three-dimensional (three-dimensional). Therefore, the obstacle can be identified even if it is hanging or floating in the air. You can

Thus, by appropriately selecting the laser light irradiation method according to the expected characteristics of the obstacle,
Obstacles can be effectively recognized in various areas.

[0021]

In the automatic guided vehicle of the present invention, the interference light of the laser light is always generated at an appropriate point in front of the route by the two or more laser light irradiation means, and the interference light is not generated when the obstacle exists. By utilizing this fact, the emission color generated from the interference light is discriminated by the image processing means and used as a criterion for the presence / absence of an obstacle, so that reliable discrimination can be performed regardless of the material, color or shape of the obstacle. Further, when the laser light irradiation means fails, naturally there is no interference light, and there is an advantage that it also functions as a fail-safe device.

Since the image processing means only identifies the emission color of the interference light, not the shape of the obstacle, it can be executed by a relatively simple program and the existing hardware is sufficient in terms of processing speed. It is economical because it can. Further, by scanning each laser beam by the scanning means and scanning the interference light, the identification range or the dimension of the range can be appropriately selected according to the expected obstacle, so that the obstacle can be recognized more accurately and accurately. Is possible.

[Brief description of drawings]

FIG. 1 is a schematic diagram of an automated guided vehicle according to the present invention.

FIG. 2 is a block diagram of a control system of an automated guided vehicle according to the present invention.

FIG. 3 (a) is a model view of the automatic guided vehicle of the present invention when in use. (B) It is an image of the video camera 3 in FIG.

FIG. 4 (a) is a model diagram of the automatic guided vehicle of the present invention when in use. (B) It is an image of the video camera 3 in FIG.

FIG. 5 (a) is a diagram showing one embodiment of a method for irradiating a laser beam on an automated guided vehicle according to the present invention. (B) It is an image of the video camera 3 in FIG.

FIG. 6 (a) is a diagram showing one embodiment of a method for irradiating a laser beam on an automated guided vehicle according to the present invention. (B) It is an image of the video camera 3 in FIG.

FIG. 7 (a) is a diagram showing one embodiment of a method for irradiating a laser beam on an automated guided vehicle according to the present invention. (B) It is an image of the video camera 3 in FIG.

FIG. 8 (a) is a diagram showing an embodiment of a method for irradiating a laser beam on an automated guided vehicle according to the present invention. (B) It is an image of the video camera 3 in FIG.

[Explanation of symbols]

 1. Automated guided vehicle 2, 2 '. Laser light irradiation device 3. Video camera 4. Rotation mechanism 5, 5 '. Laser light 6. Interfering light 7. Human

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Office reference number FI Technical display location G06T 1/00 G01S 13/93 // B61B 13/00 9406-2G G01V 9/04 S G05D 1 / 02 G06F 15/62 380

Claims (2)

[Claims] 1. At least two laser light irradiating means each capable of arbitrarily setting an irradiating direction and constantly irradiating laser light in mutually intersecting directions, and laser light emitted from the laser light irradiating means. And an image processing means for taking in the image information of the automatic guided vehicle. 2. The automatic guided vehicle according to claim 1, wherein at least one of said laser light irradiating means is provided with a scanning control means for automatically scanning its irradiation direction.