JPH0419586A - Position and azimuth recognizing method for moving body - Google Patents

Abstract

PURPOSE:To easily recognize the position and moving direction of the moving body by using a travel distance corresponding to the time interval between photodetected pulses of reflected light beams from two light reflecting means which are installed in a travel path and reflect sectorial light beams in two direction of moving body projection. CONSTITUTION:Light emitting and receiving means 2 and 3 installed on the top surface of the moving body 1 project the sectorial light beams A and B upward. The plane beam A is at right angles to the travel direction Y of the moving body 1 and the plane beam B is at an angle to it. Then the retroreflecting means 4 and 5 which reflect incident light in the same direction are provided on the ceiling surface of a room in the environment of the travel path of the moving body 1. Those beams A and B are reflected by the means 4 and 5 and their reflected light beams are photodetected by the means 2 and 3 to find the time interval between the generated photodetected pulses. The position and azimuth of the moving body 1 can be found from the travel distance of the corresponding moving body 1. Thus, the azimuth is also confirmed without providing any azimuth recognizing means.

Description

[Detailed description of the invention] [Industrial application field]

The present invention relates to a method for recognizing the position and orientation of a moving body for detecting the position and heading direction of the moving body.

[Conventional technology]

For example, when moving a moving object such as an automatic guided vehicle in a factory, a moving vehicle that assists people in a house, or a construction vehicle at a construction site along a predetermined course, the moving object itself has to keep track of its own position. If the traveling direction of the moving body (deviation from the reference direction) can be recognized while traveling, the running control of the moving body becomes extremely simple. A method of recognizing the position and orientation of such a moving body is disclosed in Japanese Patent Application Laid-Open No. 172215/1983. This consists of two sets of light-emitting light-receiving means mounted on a moving body, and a pair of return lights installed in the environment of the traveling path of the moving body and returning the light emitted from the two sets of light-emitting light-receiving means to each light-emitting light-receiving means. The apparatus includes a position recognition means including a target light reflection means, a moving distance (velocity) detection means of a moving object, and an orientation recognition means provided as a separate means from the position recognition means.

[Problem to be solved by the invention]

However, in the above conventional example, in addition to the position recognition means and the travel distance detection means, a separate direction recognition means is required, so it is desirable to be able to recognize the position and direction with even simpler equipment. It is rare. The present invention has been made in view of these points, and its purpose is to provide a method for recognizing the position and orientation of a moving body, which allows the position and direction of movement of a moving body to be easily recognized. [Means for Solving the Problems] Accordingly, the present invention reflects a fan-shaped light beam in two directions projected from a moving object by two recursive light reflecting means arranged in the environment of the moving path of the moving object. The reflected light from the lever is received by a pair of light receiving means on the moving body, and the fan-shaped light beams in the two directions are reflected by the light reflecting means as the moving body moves, and these reflected lights are The present invention is characterized in that the position and orientation of the moving body are determined from the travel distance of the moving body corresponding to the time interval of the light reception pulses generated by the light receiving means. [Operation] According to the present invention, not only the position of a moving object but also the direction can be recognized without requiring a separate direction recognition means. Embodiments] The present invention will be described in detail below based on illustrated embodiments.
In the figures and FIG. 2, 1 is a self-propelled moving body, and two sets of light emitting and receiving hands P12.3 are installed on the upper surface of this moving body 1. These light emitting/receiving means 2.3 project upward fan-shaped light beams A and B, and the planar light beam A projected by the light emitting/receiving means 2 is shown in FIG. As shown in , the planar light beam B projected by the light emitting/receiving means 3 forms an angle ψ with respect to the light beam A in a plan view so as to be perpendicular to the traveling direction Y of the moving body l. It is like that. A pair of light reflecting means 4.5 are installed at a predetermined interval di on the ceiling surface of the room in which the moving object 1 runs on the floor surface in the environment of the traveling path of the moving object 1. There is. These light reflecting means 4.5 include a recursive light reflecting means that returns incident light in the same direction, such as a corner cube (also referred to as a corner cube prism) shown in FIG.
is used. FIG. 3 shows an example of the light emitting and receiving means 2.3.
One of the lens barrels 21 arranged in the case 20 is provided with a semiconductor laser 22, a beam liter 23, a cylindrical lens 24, and a quarter wavelength plate 25 in order from the back, and a beam niblitter. The light receiver 2 is provided so as to face the side surface of the light receiver 23 . The i-line light emitted from the semiconductor laser 22 passes through the beam splitter 23 and enters the lens 2, where it is changed into a fan-shaped beam by the lens 24, and then transformed into a fan-shaped beam.
The light is projected upward through the 74-wavelength plate 25. Further, the reflected light that has been reflected by the light reflecting means 4.5 is passed through the 174-wave plate 25 again with a phase shift of half a wavelength from the emitted light, and is then reflected in the lens 24. The light is returned to a straight line and is reflected by the beam splitter 23 toward the light receiver 26 due to the phase shift, and is incident on the light receiver 6. Note that it is assumed that the traveling distance of the moving body 1 can be measured without using the number of rotations of its running wheels. Further, the pair of light reflecting means 4.5 are arranged so that a line connecting them is perpendicular to the reference direction X for the movement of the moving body 1. Further, each projection angle α of the fan-shaped light beams A and H projected by the light emitting and receiving means 2.3 is determined by a pair of light reflecting means 4.3 arranged on the ceiling surface, as shown in FIG. 2(b). 5 is within the expected range. Next, the operation will be explained. First, to explain the recognition of the orientation of the moving object 1 (deviation angle θ from the reference orientation
A is the point in time when the light emitting/receiving means 2 first receives the reflected light from the light reflecting means 4.5, and the light emitting/receiving means 2 then receives the light reflected by the other light reflecting means 5.4. The time point is b, and the light beam B is emitted by the light emitting and receiving means 3.
is reflected by one of the light reflecting means 4.5 and the light emitting/receiving hand H3 first receives the light reflected by the other light reflecting means 5.4. If d is the moving body 1 in the case shown in FIG.
While moving from point A to point A in the figure, it first passes through point 0, then point a, point b, and then point d, and at this time, the light receiver 26. 26 is
As the moving body 1 moves forward, the pulses Pc and Pa shown in FIG.
, Pb, and Pd are emitted in this order. Here, the deviation angle θ of the traveling direction Y with respect to the reference direction When the traveling distance of the moving body 1 is 11, it can be calculated as follows. dl is the distance between the two light reflecting means 4.5 as described above, and l is the pulse Pa,
Data can be obtained as the distance traveled during the generation of Pb. However, it is difficult to determine whether the angle θ obtained here is positive or negative (whether it is shifted to the right or left with respect to the reference direction If we consider the case where the directions are opposite and the angles are the same, then in this case the pulse Pa. Pb, Pc, and Pd are as shown in FIG. 8, and in this case, the light beam A from the light emitting/receiving means 2 sequentially receives reflected light from the two light reflecting means 4.5 from point a to point b. Although the traveling distance 11 is the same as that shown in FIG. From first receiving the reflected light from one of the light reflecting means 4.5 of the beam B (passing the 0 point) to receiving the reflected light from the other light reflecting means 5.4 (passing the d point) Mileage between! 2 is similar to the case shown in FIG. In other words, the traveling distance between the light receiving pulses Pa and Pb of the light emitting and receiving means 2! , and the light receiving pulses Pc, Pd of the light emitting light receiving means 3
Between the traveling distance 12 between and the deviation angle θ, the light beam A
Since there is a correlation shown in FIG. 9 according to the angle ψ between , B, it is possible to determine whether the deviation angle θ is positive or negative. Of course, when the traveling distance 11 is 0, the deviation angle θ of the moving body 1 with respect to the reference direction X is Oo, and the traveling path 1
When 1z is 0, the deviation angle θ is 1ψ. Next, regarding the recognition of the position of the moving object 1, an arbitrary point (the middle point in the figure) on the line connecting the pair of light reflecting means 4.5 is set as the origin, and the position is set as X as shown in FIG. When the y-axis is determined, the coordinates (x, y) of point d in FIG. 5 can be determined simply by geometric calculation. That is, the traveling distance of the moving body 1 between point b and point d is as shown in FIG. , then ■■■ in Figure 10
■Since each distance is . becomes. In cases other than the case shown in FIG. 5, the position can be determined geometrically in the same way. In addition, although the case where the light emitting light receiving means 2.3 emits the light beams A and B upward and the light reflecting means 4.5 is arranged above the moving object l has been described here, the present invention is not limited to this. Instead, when moving object 1 moves in the air,
The light beams A and B are directed downward, and the light reflecting means 4.5 is connected to the moving body 1.
It may be placed below. Furthermore, as shown in FIG. 4(c), as the light reflecting means 4 and 5, a digital code mark is attached to each light reflecting means 4.5 by drawing an individual mask pattern, and the light reflecting means 4. Light beam A reflected at .5. If specific information is placed on the waveform of the reflected light B, it becomes easy to arrange a plurality of pairs of light reflecting means 4.5 and guide the movable object 1 in sequence.

【Effect of the invention】

As described above, in the present invention, a fan-shaped light beam in two directions projected from a moving object is reflected by two recursive light reflecting means arranged in the environment of the moving path of the moving object, and this reflected light is moved. The light is received by a pair of light receiving means on the body, and the fan-shaped light beam in the two directions is reflected by each of the light reflecting means as the moving body moves, and these reflected lights are received by the light receiving means. The position and orientation of the moving body are determined from the traveling alternate layer of the moving body corresponding to the time interval of the light reception pulses generated by the light receiving pulse. Direction can also be recognized without requiring a separate dedicated direction recognition means.

[Brief explanation of drawings]

Fig. 1 is a perspective view schematically showing an embodiment of the present invention, and Fig. 2 (
a) (b) is a plan view and a front view of the same as above, FIG. 3 is a sectional view of the light emitting and receiving means, and FIG. Figures and explanatory diagrams, Fig. 5 is an explanatory diagram of the operation for direction recognition, Fig. 6 is a time chart of the light reception pulse same as above, Fig. 7 is an explanatory diagram of the operation in other cases,
FIG. 8 is a time chart of the received light pulses, FIG. 9 is an explanatory diagram of determining whether the angle is positive or negative, and FIG. The light emitting/receiving means and 4.degree. 5 are light reflecting means.

Claims (1)

[Claims] (1) A fan-shaped light beam in two directions projected from a moving object is reflected by two recursive light reflecting means arranged in the environment of the moving path of the moving object, and this reflected light is received by a pair of light receiving devices on the moving object. The fan-shaped light beam in the two directions is reflected by each of the light reflecting means as the moving body moves, and the light receiving means generates a received light pulse by receiving the reflected light by the light receiving means. 1. A method for recognizing the position and orientation of a moving object, characterized in that the position and orientation of the moving object are determined from the travel distance of the moving object corresponding to a time interval.