JPH0246961B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an automatic steering device for a moving body, and particularly to a device for automatically steering a moving body that moves on a plane or space, such as a car, an unmanned mobile transport device in a factory, an airplane, etc. Regarding.

BACKGROUND ART Conventionally, as a method for automatically steering a moving object such as an automobile or an unmanned transport device in a factory, there has been a method of, for example, laying a track rail on the road surface on which the moving object runs and having the moving object run on the track rail. This method has the drawback of requiring very large-scale facilities and being expensive. There is also a method for automatically steering an object moving in the air, such as an airplane, by using radio waves to guide the object. However, this method has the disadvantage that steering becomes impossible when the guided radio waves receive interference.

In order to eliminate the above-mentioned drawbacks, the following can be considered. That is, a plurality of light reflecting means that reflect light in the direction of incident light are arranged along a predetermined locus in the movement area of the moving body. On the other hand, a light beam having a predetermined spread is generated from the moving body, and the light beam is rotated and scanned in the direction in which the light reflecting means is provided. Then, the light beam reflected by the light reflecting means is received by the moving body, and the rotation angle of the light beam at that time is detected. This detected rotation angle correlates with the deviation between the moving direction of the moving body and a predetermined trajectory. Therefore, the steering direction of the mobile body is controlled based on the detected rotation angle.

The automatic steering device as described above is simpler and cheaper than conventional steering systems, and does not become unable to steer due to radio wave interference. Furthermore, since the light reflecting means does not include any electrical device or mechanical operating mechanism, there is almost no need for maintenance and inspection. Furthermore, the light reflecting means has many advantages such as being able to be shared by multiple moving objects at the same time.

Incidentally, in the above-mentioned automatic steering system using a light beam, only angle information is obtained based on the light beam reflected from the light reflecting means, but it is also possible to obtain other information from the light beam. This would hopefully result in a more useful and versatile autopilot system.

Therefore, the main object of the present invention is to provide an automatic steering system for a moving object that can obtain various information from the optical beam reflected from the light reflecting means, in an apparatus that performs automatic steering using a light beam as described above. It is to provide.

In summary, this invention arranges a plurality of light reflecting means that reflect light in the direction of incident light along a predetermined locus so that a moving body should move, and each light reflecting means has a plurality of light reflecting means that reflect light in the direction of incident light. Install a modulation means to modulate the On the other hand, a beam having a predetermined spread is rotated and scanned from the moving body in the direction of the light reflection means, the light beam reflected by the light reflection means is received, and the rotation angle of the light beam at that time is detected. . Then, the steering direction of the moving body is controlled based on the detected rotation angle. It also demodulates the received light beam, captures the demodulated data, and discriminates the data.

The above objects and other objects and features of the present invention will become more apparent from the following detailed description with reference to the drawings.

1 and 2 are diagrams for explaining the principle of an embodiment of the present invention. In particular, FIG. 1 is a side view of the moving body V, and FIG. 2 is a diagram showing the moving body V. It is a figure seen from the front. In the figure, corner cubes CC, which are an example of light reflecting means, are arranged on the ceiling or wall above the road surface on which the moving body V runs. The corner cubes CC are arranged along a predetermined trajectory along which the moving body V is to be moved. Note that the corner cubes CC may be arranged on a straight line, or may be arranged on a curved locus as shown in FIG. Here, corner cube
The CC is constructed by, for example, combining a plurality of tetrahedral prisms. The corner cube CC has an optical property of reflecting the incident light in the direction of the incident light.

Furthermore, each corner cube CC is provided with a light modulation means PM. The simplest light modulation means is one that mechanically interrupts light. For example, a disk with a plurality of slits formed therein may be rotated in front of the corner cube CC. In addition, it is also good to use the galvanometer method, the Pockels effect as electro-optic modulation, the Kerr effect, the Faraday effect as magneto-optic modulation, or the acousto-optic modulation effect.

Various types of modulation information can be considered.
For example, a number may be assigned in advance to the arrangement order of each corner cube CC, and the number may be used as the modulation information. Furthermore, information representing the position of each corner cube CC from a certain reference position may be used as modulation information.

On the other hand, a beam scanner is mounted on the top surface of the moving body V.
BS will be provided. And this beam scanner
A light beam PB with a spread angle φ is emitted from the BS. As shown in FIG. 2, the light beam PB is rotated and scanned by a beam scanner BS, for example, in an angular range of θ1. In addition, the spread angle φ of the light beam PB
is selected to a value such that at least two corner cubes CCa and CCb are illuminated by one rotational scan of the light beam PB.

Here, the beam scanner BS scans the light beam every moment.
It has, for example, a rotary encoder for detecting the rotational scanning angle of the PB. The reference angle of this rotary encoder is, for example, a beam scanner.
Selected right above BS. In addition, beam scanner
The BS is provided with light receiving means for detecting reflected light from the corner cube CC. For example, when light emitted from the beam scanner BS hits the corner cube CCa, the corner cube CCa reflects the light beam PB in the direction of the incident light, that is, in the direction of the beam scanner BS. Accordingly, the light receiving means provided in the beam scanner BS receives the reflected light from the corner cube CCa. If you read the output angle of the rotary encoder at this time, you can find the opening angle θa of the corner cube CCa with respect to the reference angle of the rotary encoder.
can be found. Similarly, the opening angle θb of the corner cube CCb with respect to the reference angle of the rotary encoder is determined.

If the opening angles θa and θb obtained as described above are not 0, it means that the moving direction of the moving body V is deviated from the line segment (predetermined trajectory) connecting the corner cubes CCa and CCb. be. If the moving direction of the moving object V is the corner cube CCa,
If there is a relationship that matches the line segment connecting CCb, both opening angles θa and θb will be 0. Therefore, if the steering direction of the moving body V is controlled so that the opening angles θa and θb obtained as described above are both 0, the moving body V can be made to travel along the trajectory in which the corner cubes CC are arranged. be able to.

FIG. 4 is an external view of a beam scanner BS used in an embodiment of the present invention. In the figure, a slit 2 is formed in a cylinder 1, and a light beam PB is emitted from this slit 2. Further, on both sides of the slit 2, light receiving sections 3 and 4 are provided for receiving the reflected light from the corner cube CC mentioned above. These light receiving sections 3 and 4 are as follows:
Various photoelectric conversion elements are used. A rotary encoder EC1 and a motor M1 are connected to the cylinder 1. The rotation of motor M1 is transmitted to cylinder 1,
This cylinder 1 is rotated. That is, motor M1
is the light beam PB by rotating the cylinder 1.
Rotate and scan. Also, rotary encoder
EC1 detects the rotation angle of motor M1 and therefore of light beam PB.

The cylinder 1 and motor M1 described above are held by a holding member 5. In particular, the cylinder 1 is rotatably held by the holding member 5, and the motor M1 is held fixedly. A rotary encoder EC2 and a motor M2 are connected to this holding member 5.
The motor M2 rotates the holding member 5, which causes the cylinder 1, rotary encoder EC1, and motor M1 to rotate on a plane perpendicular to the plane of rotation by the motor M1. Also, rotary encoder
EC2 detects the rotation angle of motor M2.

FIG. 5 is a sectional view taken along line XX in FIG. 4. In the figure, a semiconductor laser 11 is provided on the inner peripheral wall of a cylinder 1. This semiconductor laser 1
The laser beam emitted from the laser beam 1 is diffused by a lens 13, and further converted into parallel light by a lens 14. This parallel light is diffused by a lens 15 provided near the slit 2. This lens 15 diffuses light only in the longitudinal direction of the slit 2, as shown in FIG. Therefore, the lens 15 has a rectangular cross-sectional shape and has a concave curved surface only in its vertical cross-section. In this way, the light beam PB that spreads in the longitudinal direction of the slit 2 is emitted from the slit 2 to the outside. Note that the light receiving sections 3 and 4 are for receiving the light reflected from the corner cube CC, but instead of these, a beam splitter 16 and a beam splitter 16 are provided.
A light receiving section 17 may be provided to receive light from the corner cube CC reflected by the corner cube CC.

In the above configuration, the reference angle of the rotary encoder EC1 is selected to be directly above the moving body V.
The reference angle of rotary encoder EC2 is the moving object V.
is selected in the straight direction. Furthermore, the motor M1 is rotated sufficiently faster than the motor M2.

FIG. 6 is a preferred block diagram of one embodiment of the present invention. In the figure, the OR gate 60 includes
Light receiving outputs from light receiving sections 3 and 4 are given.
The output of this OR gate 60 is given to one input of each of AND gates 61 and 62.
The other input of the AND gate 61 is given the angle output from the rotary encoder EC1. Therefore, θa or θb explained in FIG. 2 is output from the AND gate 61. The output of this AND gate 61 (hereinafter referred to as θα) is given to the CPU 63. On the other hand, the other input of the AND gate 62 has
The angle output from rotary encoder EC2 is given. Therefore, from AND gate 62,
The rotation angle of the rotary encoder EC2 when the light receiving output is received from the light receiving section 3 or 4 is output. The output of this AND gate 62 (referred to as θβ) is given to the CPU 63.

Further, the light receiving outputs from the light receiving sections 3 and 4 are given to a demodulation circuit 70. The demodulation circuit 70 demodulates the received light output and provides the demodulated data to the CPU 63.

Further, the CPU 63 is given a rotation direction switching signal for the motor M1 from an M1 drive circuit 64 for driving the motor M1. This rotational direction switching signal is, for example, a signal that is at a high level when rotating the motor M1 in the forward direction, and is at a low level when rotating the motor M1 in the reverse direction. Similarly, CPU63
A rotation direction switching signal for the motor M2 is given from an M2 drive circuit 65 for driving the motor M2.

Furthermore, a timer 66, a steering motor 67, a ROM 68, and a RAM 69 are connected to the CPU 63. As will be described later, in this embodiment, the steering control of the moving body V is performed alternately based on two factors, and the timer 66 regulates the steering time in the steering control based on one of the factors. used for The steering motor 67 is a motor for controlling the steering direction of the moving body V. The ROM 68 stores operating programs for the CPU 63 as shown in FIGS. 9 to 12, for example. The RAM 69 stores various processing data, but the storage areas that are particularly interesting in this embodiment include a counter 69a, a θx register 69b, a θy register 69c, and a _θF register 69.
d.

FIG. 7 and FIG. 8 are illustrative diagrams for explaining the steering control mode of an embodiment of the present invention. 9 to 12 are flowcharts for explaining the operation of the CPU 63, and in particular, FIG.
The figure shows the main flow for automatic steering control,
10 and 11 show the subroutine in FIG. 9. Further, FIG. 12 shows an operation for determining demodulated data.

The operation of one embodiment of the present invention will be described below with reference to FIGS. 1 to 12.

First, the steps in Figure 9 (abbreviated as S in the illustration)
1, θx is detected. As shown in FIG. 7, θx is the angle that the straight direction of the moving body V makes with the line segment connecting the corner cube CCaCCb. Details of the subroutine in step 1 are shown in FIG.

In FIG. 10, in step 101, it is determined whether or not the output θα is received from the AND gate 61. If there is an output θα, then in step 102 the output θβ from the AND gate 62 is read;
It is stored in RAM69. Next, in step 103, the counter 69a is incremented by one. and,
Proceed to step 104. In this step 104, M1
Based on the rotation direction switching signal from the drive circuit 64, it is determined whether the rotation direction of the motor M1 has been switched. If it is not determined in step 104 that the rotational direction of the motor M1 should be changed, the operations from step 101 onward are repeated again. That is, in steps 101 to 104, during one scan of the light beam PB by the motor M1, the corner cube CC is
It detects how many times the reflected light is received. On the other hand, if it is determined in step 104 that the direction of rotation of the motor M1 should be changed, the process proceeds to step 105.
In step 105, it is determined whether the count value of the counter 69a is 1 or not. Now, assume that the straight direction of the moving body V is not parallel to the line segment connecting the corner cubes CCa and CCb. In this case, since the timing of receiving the reflected light from the corner cube CCa and the timing of receiving the reflected light from the corner cube CCb are different, the motor M1
The number of received light outputs obtained during one scan of the light beam PB is two. On the other hand, if the straight direction of the moving body V is parallel to the line segment connecting the corner cubes CCa and CCb, the timing of receiving the reflected light from the corner cube CCa and the corner cube CCb
The timing is almost the same as the timing at which the reflected light is received. Therefore, in this case, the number of received light outputs obtained while the motor M1 scans the light beam PB once is one. That is, in step 105, by determining whether the count value of the counter 69a is 1, it is determined whether the straight direction of the moving body V is parallel to the line segment connecting the corner cubes CCa and CCb. Detected. When it is determined in step 105 that the count value of the counter 69a is not 1,
In step 106, counter 69a is cleared. Thereafter, the operations starting from step 101 are repeated again. By repeating the operations in steps 101 to 106, when the count value of the counter 69a becomes 1, in step 107, θβ is changed to θx register 69a.
9b. Note that here, θx register 6
θβ stored in 9b is the angular output of the rotary encoder EC2 when the spreading direction of the light beam PB becomes parallel to the line segment connecting the corner cubes CCa and CCb.

Referring again to FIG. 9, after the operation in step 1, it is determined in step 2 whether θx is 0 or not. If θx is not 0, proceed to step 3. In step 3, the moving body V is steered by the steering motor 67 based on θx. In the steering in step 3, the steering motor 67 is rotated forward or reverse depending on, for example, whether θx is positive or negative. Further, the rotation angle of the steering motor 67 is controlled according to the magnitude of θx. Next, in step 4, the θx register 69b is cleared. Thereafter, the operations from step 1 onwards are repeated.

As a result of the steering in step 3, when the straight direction of the moving body V becomes parallel to the line segment connecting the corner cubes CCa and CCb, θx becomes 0. This is determined in step 2 and timer 66 is started in step 5. Next, in step 6, θy is detected. This θy is the opening angle of the reflected light from the corner cube CCa (or CCb) with respect to the reference angle of the rotary encoder EC1. In addition, when proceeding to the operation of step 6, since the straight direction of the moving body V has already been made parallel to the line segment connecting the corner cubes CCa and CCb in the operations of steps 1 to 5, the difference in the reflected light of the corner cube CCa is The angle and the opening angle of the reflected light from the corner cube CCb are equal. Here, details of the subroutine of step 6 are shown in FIG.

Next, referring to FIG. 11, in step 111, θα is read. Then, proceed to step 112.
In this step 112, from θα to _θF register 69d
A preset angle θ _F is subtracted from . continue,
At step 113, the result of the subtraction at step 112 is stored in the θy register 69c.

Referring again to FIG. 9, in step 7, θy
The steering motor 67 is controlled based on the angle θy stored in the register 69c. That is, in step 7, the steering motor 67 is controlled in the direction in which θy becomes zero. Therefore, when θ _F is set to 0, the moving body V
It is controlled to run directly under the line segment connecting the CCs.
On the other hand, when θ _F is set to either a positive or negative value, the moving body V is controlled to run on the lower right or lower left of the line segment connecting each corner cube CC. Next, in step 8, it is determined whether the timer 66 has timed up. If the timer 66 has not timed up, the operation of step 7 is repeated. After the operation in step 7 has been performed several times, it is determined in step 8 that the timer 66 has timed up, and in step 9 the angle θy stored in the θy register 69c is cleared. In the steering control of steps 5 to 9, the moving body V is brought closer to a predetermined trajectory.

As described above, in this embodiment, the moving body V is first controlled so as to be parallel to a predetermined trajectory, and then in the next step, the moving body V is controlled so as to approach the predetermined trajectory. When such alternating control is performed, the travel trajectory of the moving body V approaches a predetermined trajectory while drawing a zigzag as shown by the dashed line T in FIG. 3, and then follows the predetermined trajectory.

Next, the operation for determining demodulated data will be explained with reference to FIG. Note that the operation shown in FIG. 12 is processed as, for example, an interrupt operation. That is, when there is a demodulated output from the demodulating circuit 70, this first
The operation shown in FIG. 2 is performed.

First, in step 201, demodulated data is taken in from the demodulation circuit 70. And step
At 202, the number of the corner cube (the one that received the reflected light) is determined based on the captured demodulated data. That is, in this embodiment, a number is assigned to each corner cube CC in advance in order of arrangement,
Modulation means installed in each corner cube CC
The PM modulates the reflected light using information representing the number as modulation information. Subsequently, in step 203, it is determined whether the moving objects V are traveling in numerical order of the corner cubes CC. If the moving object V does not travel in the numerical order of the corner cube CC,
It is assumed that the moving body V is not traveling along a predetermined trajectory, and in step 204 a warning is generated from a display or a buzzer (not shown). on the other hand,
If the moving objects V are traveling in the numerical order of the corner cubes CC, the operations from step 201 onwards are repeated again.

It should be noted that the processing operation shown in FIG. 12 is only one example of the present invention, and that various processing and control can be performed depending on the modulation information of the reflected light. For example, if position information of each light reflecting means is included as modulation information, the moving object
You can see where along the trajectory the vehicle is traveling. Further, only when predetermined data is obtained from the demodulation circuit 70, the rotary encoder EC1,
By reading data from the EC2, even if light is received from a source other than the light reflecting means, the rotation angle at that time will not be read, and malfunctions can be prevented.

FIG. 13 is an illustrative view showing another embodiment of the invention. In this embodiment, the corner cubes CC are grouped into groups, and each group is separated by a fairly long distance. Now, mobile V is the first
Assuming that the moving body V is passing under the corner cube CC of the first group, the moving body V is steered based on the reflected light from the corner cube CC of the first group. However, when the moving object V passes through the first group of corner cubes CC, it becomes impossible to obtain reflected light from the first group of corner cubes CC. Therefore,
In this embodiment, the beam scanner BS' is connected to a moving body V
By tilting the vehicle in the direction of travel, a light beam PB is projected onto the corner cube CC of the second group to perform steering control.

14 and 15 are external views of the beam scanner BS' shown in FIG. 13, in particular, FIG. 14 is a view seen from the side of the moving body V, and FIG. This is a diagram. In the figure, this beam scanner BS' consists of a cylinder 1 that houses a semiconductor laser and an optical system, and a cylinder 1 that houses a semiconductor laser and an optical system, as in FIG.
Motor M1 for directly rotating the motor
and a rotary encoder EC1 for detecting the rotation angle of 1. The cylinder 1 and the motor M1 are held by a holding member 50. This holding member 5
0 is connected to a motor M3 and a rotary encoder EC3. The motor M3 rotates the holding member 50 to tilt the light beam PB as shown in FIG. Rotary encoder EC3 detects the rotation angle of motor M3. Motor M3 and rotary encoder EC3 are held by holding member 51. A rotary encoder EC2 and a motor M2 are connected to the bottom surface of this holding member 51. Similarly to the motor M2 shown in FIG. 4, the motor M2 rotates the holding member 51 on a plane parallel to the plane of movement of the moving body V. Rotary encoder EC2 detects the rotation angle of motor M2.

With the configuration as described above, if the reflected light from the corner cube CC of the first group is no longer obtained, the motor M3 is rotated to project the light beam PB onto the corner cube CC of the second group. Other operations are almost the same as those in the embodiment shown in FIG. 4, and detailed explanation thereof will be omitted.

According to the other embodiments of the invention described above, the number of corner cube CCs installed can be reduced;
Equipment costs can be reduced. Incidentally, such an embodiment would be particularly effective for controlling the steering of an automobile in a tunnel, for example. In this case, it is also possible to include information indicating the occurrence of an accident in the tunnel in the modulation information of the reflected light, and to issue an alarm or perform travel stop control when the moving object V determines this information.

Note that although the above explanation has been about the steering control of one moving body V, the corner cube CC can be shared by a plurality of moving bodies V at the same time. For example, on a road with multiple lanes, it is sufficient to arrange only one row of corner cubes at the top of any lane. In that case, θ _F set for the moving object V running in each lane may be set differently to suit each lane.

Further, in the above description, the explanation has mainly been given to a moving object that travels on the ground, but the present invention can also be applied to a moving object that flies in the air, such as an airplane. In this case, light reflecting means may be arranged on the ground (for example, a runway), and a light beam may be rotated and scanned from the moving object toward the light reflecting means on the ground. In this case, if the moving object is rolling (rotation of the moving object with respect to the moving direction of the moving object as an axis), the reference angle of the rotary encoder with respect to the ground will shift, so the steering direction calculation process of the moving object will be It is necessary to take the rolling angle into account when making corrections. Also, the pitching of the moving object (the direction of movement of the moving object is the axis, and the angle between that axis and the ground surface)
This deviation can be easily eliminated by using the embodiments shown in FIGS. 13 to 15.

Further, in the above explanation, the case where the present invention is used for steering control of a moving body has been explained, but the present invention can also be applied to a course deviation detection device that warns or displays that a moving body has deviated from a predetermined trajectory. can do.

As described above, according to the present invention, it is only necessary to arrange the light reflecting means along a predetermined trajectory instead of the conventional track rail, and it is possible to obtain a very simple and inexpensive automatic steering system for a moving body. is obtained. Furthermore, since the light reflected by the light reflecting means is modulated, the moving body can obtain various information other than angle information based on the reflected light from the light reflecting means. Therefore, the system provided for automatic steering can be shared for other processing and control, and an extremely useful and versatile automatic steering system can be obtained. Further, according to the present invention, the light beam is rotated in two directions, one in a direction perpendicular to the plane on which the moving body travels and the other in a plane parallel to the plane, and two different rotation angles are set in relation to each of these rotation directions. Since this is detected and used as a parameter for guiding the moving object, it is possible to know the deviation angle of the moving direction of the moving object with respect to the guidance course and the vertical angle of the light reflecting means with respect to the moving object from these two types of parameters. As a result, the moving object can be guided while maintaining the vertical angle between the moving object and the light reflecting means at a predetermined angle. As a result, if there is an obstacle directly above the guiding course of the moving object, the light reflecting means can be placed to avoid it, and the guiding course of the moving object can be guided without being affected by surrounding obstacles. It also has the effect of being configurable.

[Brief explanation of drawings]

1 and 2 are diagrams for explaining the principle of an embodiment of the present invention, and FIG. 1 shows a moving body V
FIG. 2 is a diagram of the mobile body V viewed from the front. Figure 3 shows the corner cube.
FIG. 3 is a diagram showing an example of the arrangement of CCs and a traveling trajectory of a moving body V. FIG. Figure 4 is an external view of the beam scanner BS. FIG. 5 is a sectional view taken along line X--X in FIG. 4. FIG. 6 is a preferred block diagram of one embodiment of the present invention. FIG. 7 and FIG. 8 are illustrative diagrams for explaining the steering control mode of an embodiment of the present invention. Figures 9 to 12 are CPU
63 is a flowchart for explaining the operation. FIG. 13 is an illustrative view showing another embodiment of the invention. 14 and 15 are external views of the beam scanner BS' shown in FIG.
FIG. 5 is a diagram of the moving body V seen from the front. In the figure, V is a moving object, BS is a beam scanner, CC is a corner cube, PM is a modulation means, and M
1 to M3 are motors, EC1 to EC3 are rotary encoders, 4 and 3 are light receiving sections, 11 is a semiconductor laser, and 70 is a demodulation circuit.

Claims (1)

[Scope of Claims] 1. An automatic steering device for a movable body that performs steering control of a movable body in order to move the movable body along a predetermined trajectory, comprising: a plurality of light reflecting means for reflecting light in the direction of incident light; means provided in association with each of the light reflecting means and modulating the reflected light from the light reflecting means; a light beam generating means that generates a light beam having a spread; a light beam scanning device that is provided in association with the light beam generating means and rotates and scans the light beam generated from the light beam generating means in the direction of the light reflecting means; means, provided in association with the light beam scanning means, light receiving means for receiving reflected light from the light reflecting means; provided in relation to the light beam scanning means, responsive to the light receiving output of the light receiving means; a rotation angle detection means for detecting the rotation angle of the light beam scanning means at that time; and controlling a steering direction of the moving body based on the rotation angle detected by the rotation angle detection means. a steering direction control means for controlling the light beam, a means for demodulating the light receiving output of the light receiving means, and a means for taking in data from the demodulating means and determining the data, the light beam scanning means moving the light beam a first light beam scanning device that rotates and scans the light beam in a direction perpendicular to the plane on which the moving body travels; and a second light beam scanning device that rotates the light beam on a plane parallel to the plane on which the moving body travels. The rotation angle detection means includes: an aperture angle detection means for detecting an aperture angle of reflected light from the light reflection means with respect to a predetermined reference rotation angle in the first light beam scanning means; a parallel rotation angle detection means for detecting a rotation angle of the second light beam scanning means when the rotation angle becomes parallel to the predetermined trajectory, the steering direction control means includes means for controlling the steering direction of the movable body based on the opening angle detected by the opening angle detection means and the parallel rotation angle detected by the parallel rotation angle detection means,
Automatic steering device for mobile objects. 2. The automatic steering device for a moving body according to claim 1, wherein the light reflecting means is arranged above a movement area of the moving body. 3. The automatic steering system for a moving body according to claim 2, wherein the light reflecting means is arranged below a movement area of the moving body. 4. Each of the modulation means modulates the reflected light using information specifying the corresponding light reflection means as modulation information,
An automatic steering device for a mobile body according to any one of claims 1 to 3. 5. The automatic steering system for a moving body according to claim 4, wherein the information specifying the light reflecting means is position information of the light reflecting means. 6. The automatic steering system for a moving body according to claim 4, wherein the information specifying the light reflecting means is information representing a number assigned in advance to the light reflecting means.