JPS61259308A - Guiding method of luminescent point follow-up type unmanned vehicle - Google Patents

Abstract

PURPOSE:To execute the highly speedy traveling and to minimize the occupied area of the mark by meaning and arranging plural luminescent points along the traveling expected channel and detecting this by a visual picture device. CONSTITUTION:Plural luminescent points 1 are arranged along the a traveling expected channel 2 or on the border of it and the wall. The luminescent points 1 are meant so that the channel shape and the driving command may be simultaneously expressed. By a TV camera 5 loaded on an unmanned moving vehicle 13, the luminescent points 1 only, whose luminance is a constant value or above, are detected. Thus, the position of the vehicle 13 on the expected channel 2, the shape of the expected channel 2 and the driving command information for the vehicle 13 are obtained. Consequently, the vehicle 13 can be guided by following up the luminescent points 1. As such a result, the occupied area of the mark for the road surface is minimized. Since the picture processing is simple, the highly speedy traveling can be executed.

Description

DETAILED DESCRIPTION OF THE INVENTION 3-1 Industrial Field of Application This invention relates to technology for guiding automatic guided vehicles and mobile robots along preset travel routes.

3-2 Conventional technology Four typical methods are described below. It runs along the path represented by .

(2) Dotted line following method Instead of drawing a straight line on the planned travel route and driving along it, reflectors such as white lines or tape are installed as a substitute for the straight line at intervals approximately equal to the dimensions of the reflectors. By approaching each point one by one, the vehicle travels along the planned travel route.

(3) Reflector barcode tracking method Reflective panels containing barcodes will be installed along the planned route.

The barcode contains information such as driving conditions, intersections, and stopping points, which is detected by visual imaging means such as ITV, and the driver drives according to the information, such as going straight, turning, and stopping, and continues along the planned route. do.

(4) Reflector tracking method with characteristic geometric shapes A reflection plate with characteristic geometric shapes is provided on the planned travel route. The geometric shape contains information such as driving conditions, intersections and stopping points, which is detected by visual image means such as ITV.
According to this information, the vehicle moves straight, turns, stops, etc., and travels along the planned route.

3-3 Problems to be solved by the invention (1) Compared to the guidance method based on natural scenes, the amount of calculation required for image processing to extract a straight line indicating the route from the image is enormous, and the size that can be mounted on the vehicle body is large. It takes too much time at the processing speed of calculation processing. Therefore, when guiding the vehicle, if the vehicle is driven at high speed, the image will be updated before the calculation is completed, making it impossible to guide the vehicle properly. Therefore, they have no choice but to travel at extremely low speeds. Practical vehicle speed cannot be obtained. Therefore, it is necessary to use artificial marks that require less calculation time.

(2) For dotted line tracing method It is necessary to set dotted lines along the curves of the driving route.

Furthermore, since marks must be placed at narrow intervals on all planned travel routes, it takes too much time to lay out the marks.

In contrast to (3) the reflector barcode tracking method and (4) the reflector guidance method characterized by its geometric shape, the design or shape of the mark represents the driving method or information about the current location. Therefore, if a part of the mark becomes dirty, the original information cannot be accurately transmitted. In other words, if the mark is defaced, it will lose its function, so do not walk or drive a vehicle over it.

Therefore, in order to avoid contamination, it is necessary to avoid markings set up on roads intended for people to walk on, but since the marks are large and occupy a large area on the road surface, it is difficult for people to walk on them. This has the practical disadvantage of having to use marks with small dimensions.

3-4 Means and effects for solving the problem A transparent ball with retroreflectivity or a bright spot of small size such as an LED is given meaning so as to express the route shape and driving command at the same time, and an unmanned moving vehicle is created. At the same time, a visual imaging device mounted on the unmanned vehicle detects only bright spots with brightness above a certain value, automatically steers the unmanned vehicle, and monitors a remote location using communication means. This is what I did.

3-5 Embodiment (1) The arrangement of bright spots and the characterization of passages are shown in FIGS. 2 and 3 in which a row of bright spots is created at the boundary of the path representing the passage. The arrangement of bright spots not only represents a path, but also provides various information by arranging them in a predetermined pattern. FIGS. 11(a) to 11(g) show examples of arrangement in which various meanings are given to the arrangement of bright spots.

The points that make up these bright spot arrays include glass beads, corner cubes, small reflectors, pieces of reflective sheets, or small light-emitting objects (LEDs, miniature bulbs) that are inexpensive, easy to install, and durable for long-term use. (nato) is used.

(2) Detection of bright spots Figure 4 shows a visual image device (200
), the case where a television camera (5) is used is shown.
In order to reliably detect a bright spot regardless of ambient disturbance light, it is desirable that the bright spot has as high a brightness as possible. When using a light emitter as a bright spot, choose one with high brightness, but in the case of a reflector with retroreflection characteristics, the brightness of the bright spot will vary greatly depending on the arrangement of the light source that illuminates it and the television camera that detects it. . In other words, a reflective object with retroreflection characteristics reflects the largest amount of light in the same direction as the light beam incident on the reflective object (the traveling direction of the reflected light is opposite to the incident light and toward the light source).

In Fig. 4, the light emitting point of the illumination device (4) and the principal point of the AV child TV camera lens are at the same angle θ and equidistant from the semi-transparent half-light beam (6). Arrange it as you like. Light from outside the illumination device (4) passes through the half-shiller (6) and enters the television camera (5). At this time, the television camera (5) receives the reflected light at equivalently the same position as the illumination device (4), which is extremely dangerous.The conditions under which this method is effective are shown below.

(3) Derivation of the positional relationship between the lighting device and the television camera In Fig. 4, the luminous flux from the lamp ■, the attenuation rate r of the luminous flux due to the half wall, the luminous flux rr of the disturbance light, the luminous flux reflectance η of the mark, and the disturbance object. Let the disturbance light flux reflectance of the surface be ηn.
In addition, in the conventional method shown in Fig. 5, if the light flux reflectance of the mark is η2, the ratio of the light flux incident on the camera from the mark to that from the disturbance object, that is, the S/N ratio, is calculated as follows. become.

<Conventional method> It is effective when used under the condition that σ, 70 loss L, Q, 507 >>η'.

Incidentally, marks having retroreflective characteristics generally reflect light with a very small spread angle with respect to the direction in which the light is incident. For example, a glass ball placed on the center line of a road forms an angle of about 1095 to 1.5 degrees.

(Refer to Figure 6) Therefore, when the distance between the light source and the reflective mark is several meters or more, η and η' have close values, but at a distance of about 5 meters or less, the value is very large compared to η'. method becomes valid.

(4) Image processing device FIG. 7 shows a case where a screen imaged by a television camera (5) is binarized.

FIG. 8 shows an image processing device that directly processes signals from a television camera (5) to determine the coordinates of each bright spot in order to quickly determine the position of the bright spot on the screen.

Next, the video signal output from the television camera (5), which explains the image processing procedure based on Fig. 8, is input to the synchronization signal separation circuit (+01), and the synchronization signal is extracted and input to the trigger circuit (103). and reset signal.

A scanning line switching signal and two screen switching signals are respectively generated.

On the other hand, the image data from the synchronization signal separation circuit (+01) is
The signal is input to a value converting circuit (102), converted into a binary signal (bright spot or not), and manually inputted to a trigger circuit (107).

The counter circuit (+05) counts pulses from the clock circuit (104) using the reset signal of the trigger circuit (103) as a reference, and outputs the value of X.

On the other hand, the counter circuit (106) counts the scanning line switching signal based on the image switching signal and outputs the value of y.

Here, X represents the number of counts until a bright spot appears, and y represents the number of scanning lines.

Next, when there is a bright spot on the screen, a latch signal is generated from the trigger circuit (107), and the x and y values are sent to the latch circuit (108).
) and output to the data terminal of the memory (110).

In addition, the counter circuit (109) counts the number of bright spots and outputs it to the address terminal of the memory (110).
When the data and address are complete, the trigger circuit (10
By generating a write signal from memory (1)
10) Record the x and y values of the bright spot.

As described above, at the same time that one screen worth of image data is sent from the television camera (5), the x and y values of all the bright spots on the screen are recorded in the memory (110), and then the arithmetic unit (111) allows the values of X+V to be extracted and subjected to arithmetic processing.

(5) Guidance and steering of the vehicle (I) When a dot array is arranged along the path, the vehicle is guided by measuring the lateral displacement and deflection angle from a straight line connecting the dot array (not shown).

(II) When placed at the boundary between the floor and wall: The position occupied by the end of the aisle in the image is recorded from the image when the vehicle is in the center of the aisle and stopped parallel to the aisle. To explain using FIG. 9, the position Y of a scanning line and the position X where a boundary appears on the scanning line are recorded as a set. The S set of coordinates recorded as described above is set as the target state when the vehicle body is in the center of the passage. On the other hand, by determining the coordinates of the bright spot (i.e., a point on the boundary of the passage) from the image obtained while driving and comparing it with the recorded coordinates above,
By knowing the bias of the vehicle with respect to the passage, it is possible to guide the vehicle in the same way as in (1).

(6) Path recognition The image actually obtained is the coordinates of the bright spot on the image, but
The installation height of the image sensor (5) of ITV Nato is 11
) and by fixing the angle (12) and installing a retroreflective object (e.g. beads) at a certain height such as the floor, it is possible to easily detect a bright spot from an unmanned vehicle (13) carrying an ITV etc. It is replaced with distance information up to (1). Also,
When a series of points is arranged along a passage, the position of the passage can be known from the distance information of the plurality of points. Furthermore, if it is placed at the boundary between the floor and wall, the positions of both ends of the passage can be known. (See Figure 10) 3-6 Effects of the Invention As described above, according to the present invention, the area occupied by marks on the road surface is reduced, and the amount of transmitted information is increased relative to the number of marks installed on the planned route. be able to.

Furthermore, since images are processed at high speed, vehicle speed can be increased, and information can also be transmitted to a remote observer via a television monitor.

[Brief explanation of drawings]

FIG. 1 is a perspective view showing an embodiment; FIG. 2 is a perspective view showing an embodiment in which bright spots are arranged along a planned route and at the same time a distinctive bright spot arrangement indicating the shape of the planned route; The figure shows an example in which a bright spot is placed along the boundary between the floor and wall of the planned route, and at the same time a distinctive bright spot arrangement that indicates the shape of the planned route is used.A perspective view, and Figure 4 shows two recursive reflections as a bright spot. FIG. 5 is a plan layout diagram showing the positional relationship between a television camera whose bright spot has maximum brightness when an object is used, and a half mirror 9 illumination device. FIG. 5 is a plan layout diagram showing the positional relationship between a conventional television camera and a lighting device. . FIG. 6 diagrammatically shows the good directivity of reflected light of a birecursion reflecting object. FIG. 7 schematically shows an image obtained by binarizing the images in FIGS. 2 and 3 based on luminance. Fig. 8 is a block diagram of the image processing device according to the embodiment of the present invention, and Fig. 9 shows a case where the bright spot is placed at the boundary between the floor and wall of the planned route, when the unmanned vehicle is in the center of the planned route, and when the unmanned vehicle is in the center of the planned route, Fig. 2 schematically shows a method for recording the positions occupied by the ends of two paths in an image from an image of a visual imaging device when stopped in the same direction. FIG. 10 schematically shows that there is a one-to-one correspondence between points on the planned route floor and images. Figure 11 shows an example of assigning various meanings to the arrangement of bright spots 1...Bright spot, 2...Planned route, 3...Wall, 4...
・Lighting device, 5...ITV, 6...Half mirror-1
7... Retroreflection object, 8... Incident parallel rays, 9...
·reflected light.

Claims (5)

[Claims] (1) In a method of guiding an unmanned moving vehicle along a preset scheduled running route, a meaning is attached to the arrangement along the scheduled running route (2) or the boundary between it and a wall. By arranging a plurality of bright spots (1) and detecting the bright spots (1) with a visual image device, the position of the unmanned vehicle on the planned route for travel, the shape of the planned route for travel, and the unmanned vehicle can be determined. A method for guiding an unmanned moving vehicle, characterized by being able to receive driving command information for the moving vehicle and guiding the moving vehicle while following a bright spot. (2) Binarize the image containing the bright spot (1) and other objects from the visual image device based on the intensity of brightness, and store the coordinate data on the screen of the bright spot (1) with high level brightness in memory (
110), and by comparing the coordinate data with data indicating the arrangement of bright spots set in advance, the bright spot (1) is stored.
2. A method for guiding an unmanned moving vehicle according to claim 1, characterized in that the unmanned moving vehicle is guided while following. (3) A method for guiding an unmanned moving vehicle by following a bright spot according to claim 1, characterized in that a light emitter with a small surface area is used as the bright spot. (4) A transparent ball with retroreflectivity is used instead of the bright spot, and a lighting device is mounted on the vehicle to illuminate the transparent ball with retroreflectivity. A method for guiding an unmanned moving vehicle by bright spot tracking as described in 2. (5) Bright spot tracking according to claim 4, characterized in that the visual image device and the illumination device are arranged equivalently on the same optical axis by using a semi-transparent mirror. A method for guiding unmanned moving vehicles.