JPH0611559A - Method and apparatus for tracking-type optical wireless communication - Google Patents

Abstract

PURPOSE:To automatically adjust an axis shift and easily search for a communication target as well as communicate more information irrespective of adverse influence or the like of external noise. CONSTITUTION:Since diffusion light 14, 15 is emitted to each other at the time of searching for communication targets, a wider searching range at the time of emission than a case where condensed light is used can be obtained to facilitate searching. In addition since a light transmitting/receiving part rotates in horizontal and elevation angle directions, searching can be done easily and securely even if there is difference in height between both communicators. If communication is performed with condensed light 13, transmission/reception with high frequency signals is possible, a loss due to light diffusion can be further reduced, and also adverse influence of external noise can be prevented, thereby enabling communication of much data.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a tracking type optical wireless communication method for automatically carrying out optical communication by loading it on a moving body such as an automated guided vehicle or a robot, and an apparatus therefor. The present invention relates to a device suitable for loading on a moving body in which use of radio waves is restricted, such as a vehicle or a robot used in a power generation plant.

[0002]

2. Description of the Related Art A conventional tracking type optical wireless communication device is described, for example, in Proceedings of the 31st Remote System Technology Conference of the Atomic Energy Society of Japan (1983), pages 82 to 88 (The American).
an Nuclear Society, Procee
dings of the 31st Confere
nce on Remote System Tech
noology, 1983, PP. 82-88). According to this conventional technique, when the imaging position inside the light receiver is detected by the two-dimensional optical sensor, the direction of the incident light is calculated, and the platform of the light receiver is moved in the direction of the incident light based on the calculated result, that is, The contents can be automatically controlled so that it faces the direction of the light transmitter.

Other conventional techniques are as follows. That is, as disclosed in Japanese Patent Laid-Open No. 62-172827 (hereinafter referred to as the second prior art), a light diffusing means for diffusing a light beam and a light diffusing means are provided inside the focal point of the light diffusing means, respectively. It has a plurality of light emitting elements, and the optical signal receivable areas formed by the light emission of the respective light emitting elements are partially overlapped and widened so as to be continuously different from each other, thereby obtaining a large amount of information. There is something.
Further, as disclosed in Japanese Patent Laid-Open No. 63-13433 (hereinafter, referred to as a third conventional technique), when a light receiver on the ground receives a light from a light emitter mounted on a vehicle, the light receiver on the ground follows the light. The mechanism controls the light emitting device on the ground so that the light for information transmission modulated by the image pickup signal of the TV camera is received by the light receiving device of the vehicle, so that the image is taken by the ground TV camera. Some home screens are displayed on the monitor. Furthermore, JP-A-62-1
As shown in Japanese Patent No. 53529 (hereinafter, referred to as fourth prior art), when a light-transmitting side vehicle equipped with a light-transmitting and light-receiving device and a light receiving side vehicle are traveling, a plurality of both are arranged on a straight line. Communication is performed by the light receiving amounts of the respective light receiving elements being the same amount, and in this state, for example, when the front light transmitting side vehicle curves, the light receiving of each light receiving element in the rear light receiving side vehicle changes, There is one in which the optical receiver mounting housing from the vehicle on the light receiving side is rotated in the horizontal direction according to the changed amount of received light so that optical communication can be performed without interruption.

[0004]

The above-mentioned prior art is premised on that the axis deviation of the light-transmitting / receiving device is adjusted within a range detectable by the two-dimensional sensor by some means at the time of starting communication. ing. However, in reality, the operator manually adjusts it, which is not always sufficient for application to an automated system. In particular, when performing optical communication between mobiles in a production facility or power plant, optical communication is often interrupted by obstacles or other mobiles. In addition, when multiple robots work autonomously in cooperation with each other,
It is necessary to search for a communication partner and transmit information. In such a case, the operator has to make manual adjustments one by one, which is difficult to automate.

The second prior art has a problem that if only diffused light is used, the loss due to the diffusion of light is large, and therefore a larger amount of information cannot be transmitted. In the third conventional technique, when the light from the light emitter of the vehicle is received by the light receiver on the ground, the tracking mechanism operates so that the light emitter on the ground faces the light emitter of the vehicle. Whether or not it is not specifically disclosed. Then, in the fourth conventional technique, when the light-transmitting side vehicle is displaced with respect to the light-receiving side vehicle, the light-receiving side vehicle faces the light-transmitting side vehicle by rotating the tracking mechanism in the horizontal direction. Since the tracking mechanism only rotates in the horizontal direction, if there is a difference in height between the light-transmitting side vehicle and the light-receiving side vehicle, the light-receiving side vehicle will not transmit the light-receiving side if the tracking mechanism rotates horizontally. There is a problem that it is not possible to face the vehicle and communication becomes impossible. This problem is the same in the second and third prior arts, and there is no disclosure about receiving light from a direction other than the determined direction. Further, in these other conventional techniques, not only consideration is given to disturbance noise, but also consideration is not given to communication of a larger amount of information.

In view of the above-mentioned problems of the prior art, an object of the present invention is to automatically adjust the axis deviation even if there is an axis deviation with the communication partner, and to easily search for the communication partner. The present invention is to provide a tracking type optical wireless communication method capable of communicating a larger amount of information regardless of the adverse effects of disturbance noise, and another object is to provide a tracking type optical wireless communication method capable of accurately implementing the above method. To provide a device.

[0007]

In the method of the present invention,
When searching for a communication partner of one and the other, when both emit diffused light and one receives the diffused light of the other, the one performs initial optical axis adjustment for the diffused light of the other, and then one Another feature is that when the initial optical axis adjustment is completed, the other performs the initial optical axis adjustment for one, and then both the one and the other communicate with each other by focused light.

In the device of the present invention, a plurality of light transmitting / receiving lenses, a light emitting device, and a plurality of light transmitting / receiving parts provided with a light receiving device, and a light receiving / receiving part installed in the light emitting / receiving part to form an image of the received light and position information of the image forming position. A two-dimensional optical sensor, a light flux changing means for selectively changing the light emitted from each light-transmitting / receiving unit into either diffused light or focused light, and each light-receiving unit in the horizontal direction and the elevation angle direction. It has a swinging means for rotating it, and a means for remotely controlling the light flux changing means and the swinging means of each of the light-transmitting and receiving parts. Further, the means for remote control, when searching for a communication partner, diffuses the light from the light emitting device in the light transmitting / receiving portion by driving the light flux changing means of the light transmitting / receiving portion for searching, and drives the swinging means by driving the swinging means. Is rotated in the horizontal direction and the elevation angle direction, and when one of the light transmitting / receiving units receives the light from the other light transmitting / receiving unit, both the light transmitting / receiving units face each other based on the output signal of the two-dimensional optical sensor, And at the time of searching, drive the light flux changing means of each of the light transmitting and receiving parts,
It is configured such that the light from both the light-transmitting and receiving parts is changed to focused light and the focused light is used for communication.

[0009]

As described above, according to the method of the present invention, diffused lights are emitted from each other when searching for a communication partner, so that the search range at the time of emission can be made wider than in the case where focused light is used. Therefore, the emitted light flux is very likely to be received by the communication partner, and the search becomes easier accordingly. Moreover, since the respective light-transmitting and receiving units rotate in the horizontal direction and the elevation angle direction, even if there is a difference in height between the two, it is possible to search easily and reliably. Conventionally, a spot having an unfocused spread is rarely used because it has no value as information. Although the spot of diffused light is inferior to the spot of focused light in terms of the information obtained, it is significantly superior in terms of efficiency when searching for a partner in space. When diffused light is used, the radiant flux density decreases, and the signal-to-noise ratio deteriorates from the viewpoint of information transmission. There is no problem in a system that does not transmit information in the diffused light state, but there are cases where it is desired to transmit information even in the diffused light state. In such a case, the deterioration of the signal-to-noise ratio can be suppressed by reducing the bandwidth of the transmission signal or increasing the light emission power of the light emitter. This can be supported by the following formula.

[0010]

[Equation 1]

Further, when the focused optical communication is performed after the completion of the initial optical axis adjustment with each other, a high frequency signal can be transmitted and received, so that not only the loss due to the diffusion of the light can be further reduced, but also the adverse effect on the disturbance noise can be reduced. It is also possible to prevent this, so that a larger amount of data communication can be performed per unit time. As described above, the device of the present invention has the light transmitting / receiving unit, the two-dimensional optical sensor, the light flux changing unit, the swinging unit, and the remote control unit, and the unit rotates the horizontal direction and the elevation angle direction. In addition, since the light from the light transmitting / receiving unit is configured to be diffused light or focused light,
The above method can be carried out accurately.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a schematic diagram showing an embodiment of a tracking type optical wireless communication device to which a tracking type optical wireless communication method according to the present invention is applied. The fixed terminal 1 shown in FIG. 1 is equipped with a light transmitting / receiving unit 2 in which a light transmitting unit and a light receiving unit are integrally configured, and is connected to a central control unit 3 by wire. The central control device 3 is provided with operation buttons provided on the operation console 4 and a display device 5 for exchanging information with the operator. In addition, fixed terminal 6 and fixed terminal 8 that do not have an interface function with the operator
The mobile terminal 10 is further provided. The fixed terminals 6 and 8 are respectively equipped with the light transmitting / receiving sections 7 and 9. The mobile terminal 10 is equipped with two light transmitting / receiving sections 11 and 12 in order to smoothly switch the communication partner. In FIG. 1, the mobile terminal 10 and the fixed terminal 6 are connected to each other by the light transmitting / receiving unit 11
And 7 face each other, and the focused light 13 is present between both 11 and 7.
The fixed terminal 1 and the fixed terminal 8 communicate with each other via the optical transmitters / receivers 2, 9 respectively.
It is looking for a communication partner by irradiating diffused lights 14 and 15 from. That is, in the tracking type optical wireless communication device of the embodiment, one terminal emits diffused light from the light transmitting / receiving unit, and the diffused light is received by the light transmitting / receiving unit of the other terminal to search for a communication partner and communicate. When you look for a partner,
After the initial optical axis adjustment is automatically performed in both the light transmitting / receiving units, the diffused light is changed to the focused light, and the focused light is used to perform the optical communication.

FIG. 2 shows an example of a concrete configuration of the light transmitting / receiving sections 2, 7, 9, 11, 12 mounted on each terminal.
In the figure, reference numeral 21a is the light transmitting / receiving section 2, 7, 9,
It is either one of the housings 11 and 12, and the reference numeral 21b represents the other housing. These housings 21a, 21
Both b have the same structure, and the platform 30a,
It is attached to 30b and is configured to be rotatable in the horizontal direction and in the elevation direction via a swinging means (not shown) by remote control such as a cable. In addition, each housing 21a, 2
Lens barrels 22a and 22b are attached to front open portions of 1b so as to be slidable in the front-rear direction, respectively.
Reference numeral b is a lens barrel drive mechanism 23a, 23b as a light flux changing means.
Driven by. Although not shown in detail, the lens barrel driving mechanisms 23a and 23b are configured to move the convex lens 24 fixed to the lens barrels 22a and 22b along the optical axis direction. As described above, each of the housings 21a and 21b has the same configuration.
Only the details will be described.

A convex lens 24 as a light-transmitting / receiving body is fixed to the front part of the lens barrel 22a, while a photodiode 25 as a light-receiving element is provided inside the housing 21a at the focal position of the convex lens 24 in a communication state. In addition to being mounted, the infrared light emitting diode 26 as a light emitting element is also mounted via the beam splitter 27, and further the housing 21a.
A two-dimensional optical sensor 28 is attached to the focal position of the convex lens 24 in a communication state via a beam splitter 29. Inside the lens barrel 22a, the photodiode 25 is arranged in the inner portion of the convex lens 24 on the optical axis, and the infrared light emitting diode 26 is arranged above the inner portion of the lens barrel so that the light emitted from the infrared light emitting diode 26 is directed to the convex lens 24 through the beam splitter 27. The two-dimensional optical sensor 28 is arranged below the beam splitter 29 so as to capture a part of the light entering through the convex lens through the beam splitter 29, and detects an axis deviation as described later. The beam splitter 27 is arranged between the convex lens 24 and the photodiode 25 on the optical axis of the convex lens 24, and the beam splitter 29 is arranged between the beam splitter 27 and the photodiode 25 on the optical axis of the convex lens. . Therefore, by rotating the light-transmitting / receiving units 2, 7, 11, 12 by the swinging means in the horizontal direction or moving in the elevation direction, the other party to be communicated can be searched for, and the lens barrel drive mechanism 23a can be used to scan the mirror. By moving the barrel 22a and changing the position of the convex lens 24 with respect to the infrared light emitting diode 26, diffused light or focused light can be emitted from the light transmitting / receiving unit.

Next, the light transmitting / receiving sections 2, 7, 9, 11, 12
A typical example of producing focused light and diffused light will be described with reference to FIGS. 3 and 4. FIG. 3 shows the principle of forming focused light and diffused light using a convex lens. In FIG. 3A, reference numeral 52 corresponds to the convex lens 24 shown in FIG. Light emitting element 51 at the focal position of
When the distance between the light emitting element 51 and the convex lens 52 is equal to the focal length of the convex lens 52, the convex lens 52
The light emitted to the left side of is a focused light. On the other hand, in FIG. 3B, when the light emitting element 51 is located closer to the convex lens 52 than the focal position of the convex lens 52, that is, when the distance between the light emitting element 51 and the convex lens 52 is smaller than the focal length of the convex lens 52. In addition, the light emitted to the left side of the convex lens 52 becomes the diffused light 54. Therefore, it is possible to selectively generate the focused light and the diffused light by changing the distance between the light emitting element 51 and the convex lens 52. FIG. 4 shows the principle of forming focused light and diffused light by using a concave mirror. In FIG. 4A, the light emitting element 56 is a concave mirror 5.
7, the light emitting element 56 and the concave mirror 5
When the distance of 7 is equal to the focal position of the concave mirror 57, the light emitted to the left side of the concave mirror 57 becomes the focused light 58. On the other hand, in FIG. 4B, when the light emitting element 56 is located closer to the concave mirror 57 than the focal position of the concave mirror 57,
That is, when the distance between the light emitting element 56 and the concave mirror 57 is smaller than the focal position of the concave mirror 57, the light emitted to the left side of the concave mirror 57 becomes diffused light 59. Therefore, the focused light and the diffused light can be selectively produced by changing the distance between the light emitting element 56 and the concave mirror 57. From the above, a convex lens is used as the light-transmitting / receiving body in this example as shown in FIG. 2. However, if either the convex lens or the concave mirror 57 is used, if it is driven by the lens barrel driving mechanisms 23a and 23b, the focused light is converted. It can be seen that it is possible to easily change to diffused light and from diffused light to focused light.

In the transmission / reception unit having such a configuration, the modulation circuit 35 is connected to the input side of the infrared light emitting diode 26 through the amplifier 36, and in order to avoid the influence of noise due to the ambient light, the signal from the upper control device is received. After being modulated by the modulation circuit 35, the infrared light emitting diode 26 is driven by amplifying the modulated signal by the amplifier 36. Further, an automatic gain control circuit (hereinafter abbreviated as AGC circuit) is provided on the output side of the photodiode 25 via an amplifier 37.
Since the signal received by the photodiode 25 is weak, the signal received by the photodiode 25 is weak, and after being temporarily amplified by the amplifier 37, the change in the received signal level is corrected by the AGC circuit and kept constant, and then modulated by the demodulating circuit 39. The data is restored by removing the signal. on the other hand,
The sensor signal processing circuit 4 is provided on the output side of the two-dimensional optical sensor 28.
The servo circuit 42 is connected via 1. The servo circuit 42 is also connected to the host controller, calculates the target value of the drive control of the platform 30a based on the detection signal from the two-dimensional optical sensor 28, and the driver circuit 43 uses the calculated target value. By amplifying with the pan head drive signal 44
Is sent to a swinging means (not shown). Further, the servo circuit 42 calculates the target value of the lens barrel position when receiving the instruction 45 from the host controller in order to obtain the diffused light necessary for searching the communication partner and adjusting the initial optical axis. Is amplified by the driver circuit 43, and the lens barrel drive signal 46 is sent to the lens barrel drive mechanism 23a. Therefore, the servo circuit 42 is connected to the lens barrel drive mechanism 23a and the swinging means via the driver circuit 43.

Next, the principle of how the two-dimensional photosensor 28 determines the direction of incident light will be described with reference to FIG. In FIG. 5, when the two-dimensional optical sensor 28 is installed at the focal position of the convex lens 24, the angle formed by the incident light 63 to the convex lens 24 and the central axis 64 of the light receiving optical system is θ, the focal length is f, and the two-dimensional The distance between the center of the optical sensor 28 and the spot light 65 is r
Then, a relation of r = f · tan θ is established between them. Here, since the focal length f is predetermined and known, if the distance r is known to the two-dimensional sensor 28, the angle θ of the incident light can be obtained. However, if the incident light is focused light, there is no problem, but since the terminal that is searching for the communication partner emits diffused light, the incident light does not become parallel rays at the terminal that receives this, so the side that receives diffused light On the two-dimensional sensor 28 of the terminal, the spot light 64 is not completely focused, and the spot light 64 is not focused on one point as described above. Therefore, the principle of obtaining the distance r when the incident light is not completely focused on the two-dimensional sensor 28 will be described with reference to FIG. In FIG. 6, the two-dimensional sensor 28 has n pieces in the x direction as indicated by the x coordinate axis 92, and y coordinate axis 9
As shown in FIG. 3, it is configured in a two-dimensional array in which m light receiving elements are arranged in the y direction. This two-dimensional sensor 2
When the diffused light is received as incident light, the light spreads over a plurality of light receiving elements and becomes an approximate spot light 95 having a minute area.
In accordance with the amount of light received as 5, the x-direction output control circuit 94 outputs the output 96 and the y-direction output control circuit 95 outputs the output 9
7 to the center of gravity position detection circuit 98, the position of the center of gravity position 101 of the approximate spot light 95 on the two-dimensional sensor 28 obtained by the center of gravity position detection circuit 98 is used as a representative point of the approximate spot and used for subsequent control. To do. Then, the x-coordinate signal 99 and the y-coordinate signal 1 of the obtained center-of-gravity position 101
00 is sent to the host controller. When the two-dimensional optical sensor 28 detects the axis deviation, the host controller moves the light-transmitting / receiving section in a direction of absorbing the axis deviation through the swinging means, and repeats this process to finally receive the diffused light. The light-transmitting / receiving unit of the terminal to be communicated faces the light-receiving / receiving unit of the terminal to communicate with. Therefore, even if the area of the spot connected on the two-dimensional optical sensor 28 is larger than that of the light receiving element, the direction of the incident light can be known. That is,
Even if the incident light is diffused light, the direction of the light source can be specified.

Further, the host controller is a two-dimensional optical sensor 28.
An example in which both the two-dimensional position information of the spot and the communication data are obtained based on FIG. In the figure, the two-dimensional optical sensor 28 formed by arranging the light receiving elements in a two-dimensional array is shown in FIG.
Each of them is composed of m light receiving elements in the y direction as indicated by the y coordinate axis 107. The host controller is the two-dimensional optical sensor 2
When the spot light is received on 8, the x-direction output control circuit 108 and the y-direction output control circuit 109 output according to the position, and the light is sent to the servo circuit 111 via the position signal processing circuit 110, so that the host controller can Control the swinging means. On the other hand, the output of the light receiving element 105 is the preamplifier 11
2, through the AGC circuit 113 and the demodulation circuit 114, the communication data is restored. By independently connecting the above-mentioned circuit group to each light receiving element 105 and switching the output thereof by the output of the position signal processing circuit 110, the communication data can be restored regardless of the position of the spot where the image is formed. Alternatively, the output of the array of the light receiving elements 105 may be used as the position signal processing circuit
It may be switched by the output of 0 and sent to the preamplifier 112.

Next, the process in which the terminal searches for a communication partner by each host controller and adjusts the initial optical axis to perform communication will be described with reference to FIGS. 8 and 9. 8 and 9, for the sake of convenience, the terminal on the right side of the drawing that emits the diffused light for search is designated by reference numeral 8 in correspondence with FIG. 2, and the diffused light for search is received first. The terminal on the right side of the middle is labeled 1. Now, since the terminals 8 and 1 search each other for a communication partner, the terminals 8 and 1 are connected to each other as shown in FIG.
It is assumed that diffused light 72, 74 is emitted as shown in FIG. At this time, each of the terminals 8 and 1 receives a command from the host controller and drives the lens barrel drive mechanism to emit the desired diffused light 72 and 74 and drive the swinging means (not shown). The transmitter / receiver is moved by rotating in the horizontal direction and the elevation angle direction. At that time, for example, the diffused light 72 from one terminal 8 is transmitted to the terminal 1
Upon receiving the light, the terminal 1 immediately informs the terminal 8 that the initial optical axis adjustment will be started. When the terminal 8 receives the notification of the start of the initial optical axis adjustment, the lens barrel drive mechanism and the swinging means are left in the same positions in response to a command from the host controller to stop the movement and the attitude change of the light-transmitting / receiving section. , Continue to send diffused light 72. At this time, the diffused light 72 from the terminal 8 has a waveform 75 in which the horizontal axis represents time and the vertical axis represents amplitude, as shown in FIG.
The signal obtained by the terminal 1 receiving the diffused light 72 is
As shown by the waveform 76, the waveform has the same frequency and the same timing as the waveform 75, but has a smaller amplitude. Next, the terminal 1 has its own two-dimensional optical sensor 2
The light-transmitting / receiving unit is directed toward the terminal 8 on the basis of the position information (axis deviation) by the unit 8. FIG. 8B shows a state in which the terminal 1 faces the terminal 8.

In this way, when the terminal 1 faces the direction of the terminal 8, as shown in FIG. 9 (a), the terminal 1 emits the focused light 77, and the initial optical axis adjustment with respect to the terminal 8 is performed. Request. At this time, the focused light 77
Since the loss due to the diffusion of light is eliminated, it becomes possible to emit the waveform 78 having a higher frequency than that in FIG. 8B. The focused light 77 having this high frequency is used for the terminal 8
As shown by the waveform 79, the signal obtained by receiving the light has the same frequency and the same timing as the waveform 78, and has a small amplitude. Focused light 7 at terminal 8
When 7 is received, the transmission / reception rear part faces the direction of the transmission / reception part of the terminal 1 based on the detection information of the own two-dimensional optical sensor 28. This state is shown in FIG. Then, when the terminal 8 faces the direction of the terminal 1 and the initial optical axis adjustment for the terminal is completed, the diffused light is converged to the focused light 8
0, and the focused light 80 is emitted to the terminal 1 as shown in FIG. At this time, the focused light 80 has a waveform 81, and the signal obtained by receiving the focused light 80 has the same frequency and the same timing as the waveform 82, and has a small amplitude. become.

Therefore, when the terminals 8 and 1 complete the initial optical axis adjustment with each other and communicate with the focused lights 77 and 80, signals can be transmitted and received with the high frequency waveforms 81 and 82, so that the loss due to the diffusion of light is further increased. Not only can it be made smaller, but adverse effects on disturbance noise can also be prevented, which allows a larger amount of data communication per unit time. Further, since the diffused lights 72 and 74 are emitted to each other when searching for a communication partner, the search range at the time of emission can be made wider than that in the case where focused light is used. It is very likely that the data will be received by the terminal 1, and the search becomes easier. Moreover, since each swinging means rotates the light-transmitting and receiving parts in the horizontal direction and in the elevation angle direction, even if there is a difference in height between the two, it is possible to easily and surely search, and the initial light is transmitted. The axis can be reliably and automatically adjusted. Then, in the illustrated embodiment, an example in which the host controller uses the center of gravity of the approximate spot light 95 connected on the two-dimensional optical sensor 28 as the positional information from the two-dimensional optical sensor 28 during the search is the positional information of the optical axis shift. However, even if the representative point of the light imaged on the two-dimensional optical sensor is used as the position information, the same operational effect can be obtained. In addition, since the terminals 1, 6, 8 and 10 equipped with the light transmitting / receiving section are composed of a plurality of terminals, which are fixed type and movable type, it is particularly necessary for an operator to enter the mobile type terminal. It can be used in an environment where it is not possible, and at that time, even if the terminal may lose communication due to obstacles around it, it is easy to re-communicate by moving the terminal. Further, in the illustrated embodiment, each of the light transmitting / receiving units 2, 7, 9, 1
1 and 12 show the example in which the light receiving element 25 and the two-dimensional optical sensor 28 are provided, but instead of these, if only a two-dimensional optical sensor that outputs the position of the image connecting the received light is used, that is all that is required. It is also possible to simplify the configuration of the light transmitting / receiving unit. Further, an example in which the light emitting device 26 and the light receiving device 25 are integrally assembled as the light transmitting / receiving unit of each terminal is shown.
The present invention can be applied to a tracking type optical wireless communication device including a light emitting unit and a light receiving unit, each of which is separately configured, that is, a light emitting unit and a light receiving unit are separately configured. In this case, a lens barrel driving mechanism as a light flux changing unit is provided in the light emitting unit, and a swinging unit is provided in at least one of the light emitting unit and the light receiving unit, and the swinging unit and the lens barrel driving mechanism are provided in the host controller. It can also be applied to those remotely controlled by.

[0022]

As described above, according to claim 1 of the present invention, diffused light is emitted at the time of search, and when one receives the other light, it moves in the horizontal direction and the elevation angle direction to obtain the initial light. In addition to adjusting the axis, the other also adjusts the initial optical axis, and after that both sides communicate with each other by focused light, so even if there is an axis deviation with the other party to communicate, the axis deviation It automatically adjusts and easily searches for the communication partner,
There is an effect that a larger amount of information can be communicated regardless of the adverse effects of disturbance noise. According to the second aspect, since the diffused light is changed to the focused light when one of the initial optical axis adjustments is completed, the initial optical axis adjustment is performed as compared with the case where the initial optical axis adjustment is performed with the diffused light as it is. This can be performed quickly and accurately, and according to claim 3, either the center of gravity of the image connecting the light received from the communication partner or the representative point is obtained, and the optical axis shift is made based on the obtained position. Since it moves in a direction that absorbs light, the position of the light emission source can be reliably obtained even with diffused light. According to claims 4 to 6, 8 and 9, since the diffused light can be emitted while rotating in the horizontal direction and the elevation angle direction during the search, and the diffused light can be changed to the focused light after the initial optical axis adjustment. According to the eighth and ninth aspects, there is an effect that the method of claims 1 and 2 can be carried out accurately, and in particular, according to the eighth and ninth aspects, the configuration of the light transmitting / receiving section can be simplified. According to claims 7 and 10, since it can be used in an environment where workers cannot enter, it is particularly useful in a nuclear power plant, and according to claim 11, the method of claim 3 can be accurately implemented, According to claim 12, each position information can be communicated.

[Brief description of drawings]

FIG. 1 is a schematic diagram showing an embodiment of a tracking type optical wireless communication device to which a tracking type optical wireless communication method according to the present invention is applied.

FIG. 2 is an explanatory diagram showing a specific configuration example of a light transmitting / receiving unit.

3A and 3B are an explanatory view of a principle of obtaining focused light when a convex lens is used and an explanatory view of a principle of obtaining diffused light in FIG. 3B.

FIG. 4 is an explanatory diagram (a) of the principle of obtaining focused light and an explanatory diagram (b) of the principle of obtaining diffused light when a concave mirror is used.

FIG. 5 is an explanatory diagram of the principle of determining the direction of incident light by a two-dimensional photosensor.

FIG. 6 is an explanatory diagram of the principle when the two-dimensional optical sensor detects approximate spot light.

FIG. 7 is an explanatory diagram when a two-dimensional optical sensor detects spot light.

FIG. 8 is an explanatory view (a) when diffused lights are emitted from each other and an explanatory view (b) when one of them adjusts an initial optical axis.

9A and 9B are explanatory views when one requests initial optical axis adjustment to the other, explanatory views when the other side adjusts the initial optical axis, and FIG. Explanatory drawing (c).

[Explanation of symbols]

1, 6, 8 ... Fixed terminal, 10 ... Mobile terminal,
2, 7, 9, 11, 12 ... Transmitting / receiving unit, 13, 53, 5
8, 77, 80 ... Focused light, 14, 15, 54, 59, 7
2, 74 ... Diffused light, 21a, 21b ... Housing, 24, 52
... a convex lens as a light transmitting / receiving body, 25 ... a photodiode, 26 ... an infrared light emitting diode, 28 ... a two-dimensional optical sensor, 57 ... a concave mirror as a light receiving / receiving body.

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁵ Identification code Office reference number FI technical display location H04B 10/22

Claims (13)

[Claims] 1. When searching for a communication partner of one side and the other side, both emit horizontal light and vertical direction while emitting diffused light, and when one receives the other diffused light, the one is horizontal. Direction and elevation angle direction to perform the initial optical axis adjustment for the other diffused light, and when one side completes the initial optical axis adjustment, the other side moves in the horizontal direction and elevation angle direction to perform the initial optical axis adjustment for one. A tracking type optical wireless communication method, characterized in that both the one and the other communicate with each other by focused light. 2. When one end of the initial optical axis adjustment,
2. The diffused light is converted into the focused light.
Tracking optical wireless communication method described in. 3. At the time of initial optical axis adjustment, the position of either the center of gravity or the representative point of the image of the light received from the other communication partner is determined,
2. One moves in a direction of absorbing an optical axis shift with respect to the other optical axis based on the obtained position.
Tracking optical wireless communication method described in. 4. A light-sending lens, a light-sending unit provided with a light-emitter installed at a focal position of the light-sending lens facing the lens surface, and a lens surface at a focal position of the light-receiving lens and the light-receiving lens. And a two-dimensional optical sensor for forming an image of the received light and outputting position information of the image-forming position, based on the position information of the two-dimensional sensor. In the tracking type optical wireless communication device controlled so that the light transmitting unit and the light receiving unit are faced to each other and the information is transmitted by the propagation of light from the light transmitting unit to the light receiving unit, Luminous flux changing means for selectively changing the luminous flux to either diffused light or focused light, and swinging means for rotating at least one of the light transmitting portion and the light receiving portion in the horizontal direction and the elevation angle direction, The light flux changing means and the swinging means are remote from each other. A tracking type optical wireless communication device comprising: a controlling unit. 5. A plurality of light-transmitting / receiving bodies, a light-emitting device, and a plurality of light-receiving / receiving parts provided with the light-receiving device, and a light-receiving / light-receiving part installed in the light-receiving / light-receiving part. Dimensional optical sensor, light flux changing means for selectively changing the light emitted from each of the light-transmitting and receiving sections to either diffused light or focused light, and a neck for rotating each of the light-transmitting and receiving sections in the horizontal direction and the elevation angle direction. And a means for remotely controlling the light flux changing means of each of the light transmitting and receiving portions and the swinging means, and the means is a light flux changing means of the light transmitting and receiving portions for searching when mutually searching for a communication partner. The light from the light emitting device in the light transmitting / receiving unit is diffused by driving, and the light transmitting / receiving unit is rotated in the horizontal direction and the elevation direction by driving the swinging means. When light is received, the dual signal is output based on the output signal of the two-dimensional optical sensor. One of the light-transmitting and light-receiving units faces each other, and at the time of searching, the light-flux changing unit of each of the light-transmitting and receiving units is driven to change the light from both the light-transmitting and receiving units into focused light. Optical wireless communication device. 6. A plurality of terminals, each having a light-transmitting / receiving body, a light-emitting device, and a light-receiving / receiving unit provided with the light-receiving unit, and a plurality of terminals installed in the light-receiving / receiving units of the respective terminals to form an image of the received light, A two-dimensional light detection sensor that outputs position information of the image position, a light flux changing unit that selectively changes the light emitted from the light transmitting / receiving unit of each terminal to either diffused light or focused light, and each terminal It has a swinging means for rotating the light transmitting and receiving portion in the horizontal direction and the elevation angle direction, and means for remotely controlling each of the light flux changing means and the swinging means of the light transmitting and receiving portion in each terminal, and the means are mutually At the time of searching for a communication partner, the light from the light emitting unit in the light transmitting / receiving unit is diffused by driving the light flux changing unit of the search terminal, and the transmitting / receiving unit is rotated in the horizontal direction and the elevation angle direction by driving the swinging unit. One of the tar When the light transmitting / receiving unit of the terminal receives the light from the light transmitting / receiving unit of the other terminal, both the light transmitting / receiving units face each other based on the output signal of the two-dimensional optical sensor, and at the time of searching, the respective terminals are transmitted. 2. The tracking type optical wireless communication device, characterized in that the light flux changing means of (1) is driven to change the light from both the light transmitting and receiving parts into focused light. 7. The tracking type optical wireless communication device according to claim 6, wherein the plurality of terminals include a fixed terminal fixed at a fixed position and a mobile terminal configured to be movable. 8. A light-transmitting lens, a light-emitting device, a light-transmitting / receiving unit provided with a two-dimensional light detection sensor for forming an image of received light and outputting position information of the image-forming position, and a light-emitting / receiving unit emitting light. Beam changing means for selectively changing the light to be diffused light or focused light, a swinging means for rotating the light transmitting / receiving portion in the horizontal direction and the elevation angle direction, and the light beam changing means of each light transmitting / receiving portion. And a means for remotely controlling each of the swinging means, the means for diffusing the light from the light emitting device in the light transmitting and receiving portion by driving the light flux changing means at the time of searching for a communication partner, and swinging means. Drive the optical transmitter and receiver to rotate in the horizontal and elevation directions, and when one of the transmitter and receiver receives the light from the other transmitter and receiver, both transmitter and receiver based on the output signal of the two-dimensional optical sensor. When the departments face each other and search, Driving the light flux changing means of the light receiving part,
A tracking type optical wireless communication device, characterized in that light from both of the light transmitting and receiving parts is changed to focused light. 9. A plurality of terminals each equipped with a light-transmitting lens, a light-emitting device, a light-transmitting / receiving unit provided with a two-dimensional light detection sensor for forming an image of received light and outputting position information of the image-forming position, Luminous flux changing means for selectively changing the light emitted from the light transmitting / receiving portion of each terminal to either diffused light or focused light, and swinging means for rotating the light transmitting / receiving portion in the horizontal direction and the elevation angle direction. , A means for remotely controlling each of the light flux changing means and the swinging means of each terminal, and the means for driving the light flux changing means of the search terminal at the time of searching for a communication partner When the transmitter / receiver of one terminal receives the light from the transmitter / receiver of the other terminal while diffusing the light from the transmitter and rotating the transmitter / receiver in the horizontal and elevation directions by driving the swinging means. Then, the two-dimensional light Both light-transmitting and light-receiving parts face each other based on the output signal of the sensor, and at the time of searching, drive the light flux changing means of each terminal to change the light from the light-transmitting and light-receiving parts of both terminals to focused light. Tracking type optical wireless communication device. 10. The tracking type optical wireless communication device according to claim 9, wherein the plurality of terminals include a fixed terminal fixed at a fixed position and a mobile terminal configured to be movable. 11. The position information of the optical axis shift, wherein the means uses either the barycentric position of the image formed by the received light on the two-dimensional optical sensor or the representative point of the image as position information of the optical axis shift. ~
The tracking type optical wireless communication device according to any one of items 6, 8 and 9. 12. A tracking system according to claim 5, 6, 8 or 9, wherein said means superimposes position or orientation information of the light transmitter / receiver on optical communication data and transmits the information. Optical wireless communication device. 13. The light-transmitting / receiving body is composed of either a convex lens or a concave mirror.
9. A tracking type optical wireless communication device according to item 9.