JPH08125999A - Reflection type image transmission method - Google Patents

Abstract

PURPOSE: To transmit the output image of an image pickup machine fitted to a mobile object to a fixed station while fixing a transmission antenna. CONSTITUTION: A transmission antenna 5a for transmitting the radio wave signal of an output image from an image pickup machine 3 in any prescribed direction on the mobile object, radio wave reflecting plane 41 crossing the transmitting direction of the transmission antenna 5a, control means 48 for controlling the normal azimuth/ elevation angle of the reflecting plane 41, and attitude measuring means 49 for measuring the attitude of the mobile object 1 on a ground coordinate system are fitted to the mobile object 1. Corresponding to the move of the mobile object 1, this time transmission azimuth/elevation angle of the transmission antenna 5a on the ground coordinate system is calculated from the measured value of the attitude measuring means 49 and the prescribed direction, and this time transmission azimuth/elevation angle of a reception antenna 15a on the ground coordinate system watched from the mobile object 1 is calculated. Then, this time normal azimuth/elevation angle of the reflecting plane 41 for reflecting the radio wave signal made incident from this time transmission azimuth/elevation angle to this time transmission azimuth/elevation angle is calculated, and the output image of the image pickup machine 3 is transmitted by turning the reflecting plane 41 toward this time normal azimuth/elevation angle.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a reflection type image transmission method, and more particularly to an image transmission method for wirelessly transmitting an output image of an image pickup device mounted on a moving body to a fixed station by an antenna having a strong directivity.

[0002]

2. Description of the Related Art When working in a restricted area for people or an area in which people are at risk, a work machine such as a bulldozer or a dump truck can be used based on images and images (hereinafter referred to as images) from the work area. It may be operated remotely from a remote control room. An example of the image for remote control is an output image of an image pickup device attached to the work machine. Wireless image transmission is performed by remote control in order to avoid a situation in which the movement range of the work machine is limited by a wired transmission cable.

In the conventional wireless image transmission, an image transmission device using a radio wave in a microwave band of, for example, about 50 GHz is widely used. However, since this image transmission device uses a high-gain antenna having a strong directivity, it is necessary to make the transmission antenna and the reception antenna face each other when transmitting the image. In order to transmit an image for remote control using this image transmission device, for example, it is necessary to control a transmission antenna attached to the work machine according to the movement or turning of the work machine. In view of this need, the present inventors have developed an image transmission method for automatically controlling the attitude of a transmitting antenna attached to a moving body in accordance with the movement of the moving body, and are disclosed in Japanese Patent Application No. 6-104199 and Japanese Patent Application No. 6-104199. No. 226265.

Japanese Patent Application No. 6-104199 discloses a method of transmitting an image from a moving body equipped with a position measuring device by a satellite navigation system (hereinafter sometimes referred to as GPS). Referring to FIG. 5, in Japanese Patent Application No. 6-104199, the three-dimensional coordinates of the fixed station 12 are obtained in advance by surveying, and the three-dimensional coordinates of the moving body 1 corresponding to the movement are measured by the GPS position measuring device 6, From the three-dimensional coordinates of the mobile unit 1 and the fixed station 12, the transmitting antenna 5a of the mobile unit 1 calculates the transmission azimuth and elevation angle facing the receiving antenna 15a of the fixed station 12, and the transmitting antenna 5a according to the movement of the mobile unit 1a. The image is transmitted from the mobile unit 1 to the fixed station 12 by directing to the transmission direction and the elevation angle. In the figure, 5 is a transmitter and 15 is a receiver.

Japanese Patent Application No. 6-226265 discloses a method for transmitting an image from a moving body to which an image processing device with a second image pickup device is attached. Referring to FIG. 4, Japanese Patent Application No. 6-226265 discloses that a moving body 1 includes an image pickup device 3, a transmitter 5 with a transmitting antenna 5a, and a second image pickup device 7.
Attached image processing device 8, transmission antenna 5a, and second imaging device 7
Is attached to the attitude control means 9 for controlling the same in the same direction, the second imaging device 7 photographs the reception antenna 15a of the fixed station 12 according to the movement of the moving body 1, and the second image is detected by the image processing device 8.
The transmitting antenna 5a faces the receiving antenna 15a by controlling the orientation of the second imaging device 7 by the attitude control means 9 so that the coordinates of the image of the receiving antenna 15a in the output image of the imaging device 7 are always constant. The image is transmitted while maintaining the orientation. In the figure, reference numeral 13 denotes a target near the receiving antenna 15a, and the image processing device 8 may detect the image of the target 13 instead of the image of the receiving antenna 15a.

[0006]

In the image transmission method described above, the attitude of the transmitting antenna 5a is controlled by using, for example, a pan-and-tilt attitude control means 9 (see FIG. 4). Transmitting antenna 5a
Is sufficiently lightweight, the attitude control means 9 is relatively small.
Thus, the attitude of the transmitting antenna 5a can be made to follow the movement and turning of the work machine. But the transmitting antenna 5a
When the weight is heavy, for example, the attitude of the commercially available simple radio in which the transmitting antenna 5a and the transmitter 5 are integrally formed is changed to the attitude control means 9
There are the following problems when controlling by.

(1) When the work machine moves or turns at a high speed, a large attitude control means having a large driving force is required to quickly control the attitude of the heavy transmission antenna by following the movement of the work machine. . (2) When the vibration or shock during work of the work machine is large, there is a risk of damage to the attitude control means for maintaining the attitude of the heavy transmission antenna, especially the drive unit, and the reliability of image transmission decreases.

An object of the present invention is to solve the above problems, and to provide a reflection type image transmission method for wirelessly transmitting an image from a mobile unit to a fixed station with a transmission antenna fixed.

[0009]

With reference to the embodiment shown in FIG. 1, a reflection type image transmission method of the present invention uses an output image of an image pickup device 3 mounted on a moving body 1 moving on the ground surface from the moving body 1 to the ground surface. In the image transmission method of transmitting to the fixed station 12 of the
In addition, a directional fixed transmission antenna 5a and a transmission antenna for transmitting a radio signal of an output image of the image pickup device 3 in a predetermined direction on the moving body 1
The radio wave reflection surface 41 arranged to intersect the transmission direction of 5a, the reflection surface attitude control means 48 for controlling the azimuth and the elevation angle of the normal line of the reflection surface 41, and the attitude measurement means for measuring the attitude of the moving body 1 in the ground coordinate system. 49 is attached to the fixed station 12, and the directional receiving antenna 15a is provided on the fixed station 12 to measure the attitude of the mobile unit 1 according to the movement of the mobile unit 1.
The current transmission azimuth and elevation angle of the transmitting antenna 5a in the ground coordinate system in the ground coordinate system are calculated from the posture of the mobile body 1 measured in step 1 and the predetermined orientation, and the current transmission azimuth and elevation angle of the reception antenna 15a in the ground coordinate system viewed from the mobile body 1 are calculated. Seek the transmitting antenna 5
Calculate the current normal direction and elevation angle of the reflecting surface 41 that reflects the radio wave signal incident from the current transmission direction and elevation angle of a toward the current transmission direction and elevation angle of the receiving antenna 15a, and set the reflection surface 41 to the current normal direction and elevation angle. The output image of the image pickup device 3 from the mobile unit 1 to the fixed station is obtained by repeating the cycle from the calculation of the current transmission azimuth and elevation angle of the transmission antenna 15a to the current normal azimuth of the reflection surface 41 and the orientation to the elevation angle. It is transmitted to 12.

Preferably, a position measuring device 6 based on a satellite navigation system is attached to the mobile unit 1, and the current position of the mobile unit 1 measured by the position measuring unit 6 and the position of the receiving antenna 15a of the fixed station 12 indicate the receiving antenna 15a. The transmission azimuth and elevation are detected.

[0011]

The transmitting antenna 5a and the receiving antenna 15a used in the present invention can be antennas having a strong directivity for transmitting and receiving a radio wave signal of about 50 GHz, for example, and belong to the prior art. Such a radio signal has a property close to that of light, and is substantially specularly reflected by the intersection with the reflection surface 41. By utilizing this property, it is possible to change the azimuth and elevation angle of the radio signal by adjusting the azimuth and elevation angle of the normal line of the reflecting surface 41 while the transmission antenna 5a is fixed to the moving body. The transmission distances of the transmitting antenna 5a and the receiving antenna 15a can be appropriately selected according to the distance between the mobile unit 1 and the fixed station 12.

The current transmission azimuth and elevation angle of the radio signal incident on the reflecting surface 41 (hereinafter, also referred to as incident radio signal) in response to the movement of the moving body 1 in the ground coordinate system are shown on the moving body of the transmitting antenna 5a. It is calculated from the transmission direction and the attitude of the mobile unit 1 in the ground coordinate system. In FIG. 1, the mobile body 1 fixes the transmitting antenna 5a vertically upward at an initial position parallel to the ground surface, and a reflector 42 is provided vertically above the transmitting antenna 5a. One surface of the reflecting plate 42 is made to face the transmitting antenna 5a to form the reflecting surface 41, and the radio signal from the transmitting antenna 5a is reflected on the reflecting surface.
It enters 41. However, the transmitting direction of the transmitting antenna 5a in the present invention is not limited to the example of FIG. The material of the reflection plate 42 may be steel, aluminum, or any other material having a high reflectance for radio signals.

The radio signal reflected by the reflecting surface 41 (hereinafter,
The azimuth and elevation angle to be reflected (which may be referred to as a reflected radio wave signal) are obtained from the current transmission azimuth and elevation angle in the ground coordinate system of the receiving antenna 15a viewed from the mobile body 1. In FIG. 1, a position measurement device 6 based on a satellite navigation system is attached to the mobile unit 1, and the current transmission direction and the current transmission position of the mobile unit 1 measured by the position measurement unit 6 and the position of the receiving antenna 15a of the fixed station 12 measured in advance are used. The elevation angle is calculated. However, the method of detecting the transmission azimuth and the elevation angle this time is not limited to the illustrated example, and for example, the image processing device 8 with the second image pickup device 7 shown in FIG. 4 is attached to the moving body 1 and the second image pickup device 7 automatically sets the receiving antenna 15a. It is also possible to obtain the transmission direction and elevation angle this time by measuring the collimation direction and elevation angle while tracking.

Since the incident radio wave signal and the reflected radio wave signal are symmetrical with respect to the normal line of the reflection surface 41, the present transmission direction and the elevation angle of the incident radio wave signal and the current transmission direction to which the reflected radio wave signal should be reflected in the surface coordinate system. From the elevation angle, the current normal direction and elevation angle of the reflecting surface 41 can be calculated by the equations (1) and (2). However, for example, as shown in FIG. 1, when the radio wave signal is incident on the reflection surface 41 from below vertically, if there is no current transmission direction of the incident radio wave signal, the current normal direction of the reflection surface 41 is calculated as follows.
Instead of (1), it is calculated by equation (3). The attitude control means 48 is driven based on the calculated normal direction and elevation angle this time, and the reflection surface 41
The azimuth and elevation angle of the normal line are directed to the normal direction and elevation angle this time.

[0015]

[Equation 1]

According to the movement of the moving body 1, the present transmission azimuth and elevation angle of the incident radio wave signal are calculated, the current transmission azimuth and elevation angle of the reflected radio wave signal to be reflected are detected, the present reflection azimuth and elevation angle of the reflecting surface 41 are detected. By repeating the cycle of calculating and the orientation of the normal direction of the reflecting surface 41 to this time and the orientation to the elevation angle, the radio wave signal transmitted from the transmitting antenna 5a is always directed to the receiving antenna 15a regardless of the position and orientation of the mobile body 1. Can be sent out.

Thus, the object of the present invention is to provide a "reflection image transmission method for wirelessly transmitting an image from a mobile unit to a fixed station while the transmission antenna is fixed".

[0018]

FIG. 2 shows an example of a radio wave reflection means 40 having a reflection plate 42 and its attitude control means 48. The attitude control means 48 is attached to the movable body 1 so as to be rotatable around the rotation axis 43, and is provided with a reflection plate.
42 is rotatably supported about a pivot 44. Expression
It is possible to control the azimuth of the normal line of the reflecting surface 41 by driving the rotation motor 45 based on the present normal direction of (1) or (3) and rotating the attitude control means 48 around the rotation axis 43. it can. Preferably, the reflecting surface 41 is rotatable about the rotation axis 43 by more than 360 °. Further, for example, the rotation motor 46 is driven based on the current normal elevation angle of the expression (2), and the reflection plate 42 is rotated around the pivot shaft 44 to control the elevation angle of the normal surface of the reflection surface 41. it can. The normal elevation angle changes this time according to the change in the height direction and the change in the inclination of the moving body 1. However, in normal remote operation, the reflecting surface 41 can rotate about 30 ° around the pivot 44. It's enough. Reference numeral 47 in the figure denotes a speed reduction mechanism.

FIG. 3 shows a radio wave reflecting means 40 having a curved reflecting plate 42a having a convex shape toward the transmitting antenna 5a. Curved reflector 4
Since the radio wave signal reflected by the reflection curved surface 41a of 2a has weaker directivity than the reflection radio signal of the reflection surface 41 shown in FIG. 2, for example, the azimuth and elevation angle of the normal line of the reflection curved surface 41a are expressed by the equations (1) and (2). Even when the normal direction and elevation angle calculated this time do not exactly match, the receiving antenna 15a of the fixed station 12 can receive a certain quality image. By designing the curvature of the reflecting curved surface 41a based on the displacement width of the normal elevation angle of the reflecting surface 41 and the directivity of the transmitting antenna 5a in the normal remote control work,
As shown in FIG. 3, the pivot 44 of the attitude control means 48 can be omitted. If a spherical reflector (not shown) is used instead of the curved reflector 42a shown in FIG. 3, the directivity of the reflected radio signal is further weakened, and when the moving body 1 turns at high speed or when the vehicle 1 is steeply inclined. Can also be expected to prevent the interruption of image transmission.

The image transmission method in which the radio wave reflecting surface 41 is provided on the moving body 1 has been described above, but the reflecting surface 41 is also provided on the fixed station 12.
It is also possible to provide (not shown) and utilize the reflecting surface 41 of the fixed station 12 to perform image transmission. For normal remote operation, it is sufficient to fix the receiving antenna 15a and perform image transmission. However, for example, when the moving body 1 moves out of the receivable range of the receiving antenna 15a, if the reflecting surface 41 of the fixed station 12 is used, the radio wave signal transmitted from the moving body 1 out of the receivable range is received. It can be received by the antenna 15a. Fixed station 1 in this case
It is necessary to control the reflecting surface 41 of 2 according to the movement of the moving body 1. For example, the moving body 1 and the fixed station 12 are provided with transmitters and receivers for the measured values of the position measuring device 6, and the fixed station 12 Mobile 1
It is possible to control the reflecting surface 41 by receiving the current position of.

Further, a receiving vehicle such as an automobile (not shown)
The reflective image transmission method of the present invention can be effectively applied to the case where image transmission is performed between the mobile body 1 having the receiving antenna 15a attached thereto and the mobile antenna 1 having the transmitting antenna 5a attached thereto and the receiving mobile body. Further, the present invention is not limited to the one-way image transmission from the mobile station 1 to the fixed station 12, but the fixed station 12 to the mobile station 1.
It can also be applied to image transmission to. For example, by making the transmitter 5 and the receiver 15 shown in FIG. 1 each capable of transmitting and receiving an image, a bidirectional image transmission becomes possible in FIG.

[0022]

As described above in detail, in the reflection type image transmission method of the present invention, the radio wave signal transmitted from the transmitting antenna fixed to the moving body in a predetermined direction intersects with the reflection surface, and the normal line of the reflection surface. Since the image transmission from the moving body to the fixed station is performed by controlling the azimuth and elevation angle and reflecting the radio wave signal toward the receiving antenna of the fixed station, the following remarkable effects are obtained.

(1) Image transmission from a mobile unit to a fixed station can be performed with the transmission antenna of the mobile unit fixed. (2) By using a light reflector, the driving force for controlling the attitude of the reflecting surface can be minimized and the reflecting surface attitude controlling means can be miniaturized. (3) Further, since it is possible to avoid the occurrence of a failure in the drive unit of the attitude control means, it is possible to expect an improvement in reliability of image transmission. (4) Further, since the reflecting surface can be controlled at high speed, it is possible to quickly respond to the movement of the moving body and avoid interruption of image transmission. (5) By using the curved reflector, the directivity of the reflected radio wave signal is weakened, and continuous image transmission can be performed without interruption even when the moving body changes its azimuth at a high speed or changes its inclination. (6) Further, by using the curved reflecting plate, the control of the reflecting surface can be simplified and the reflecting surface attitude control means can be simplified. (7) It can also be applied to bidirectional image transmission between a mobile unit and a fixed station.

[Brief description of drawings]

FIG. 1 is an explanatory diagram of an embodiment of the present invention.

FIG. 2 is an explanatory diagram showing an example of a radio wave reflection means of the present invention.

FIG. 3 is an explanatory view showing another example of the radio wave reflection means of the present invention.

FIG. 4 is an explanatory diagram of an example of a conventional technique.

FIG. 5 is an explanatory diagram of another example of the conventional technique.

[Explanation of symbols]

 1 Moving Object 3 Imager 5 Image Transmitter 5a Transmitter Antenna 6 Position Measuring Device 7 Second Imager 8 Image Processing Device 9 Attitude Control Means 12 Fixed Station 13 Target 15 Image Receiver 15a Receive Antenna 40 Radio Wave Reflector 41 Reflective Surface 41a Reflective curved surface 42 Reflective plate 42a Curved reflective plate 43 Rotation axis 44 Pivot axes 45, 46 Rotation motor 47 Reduction mechanism 48 Attitude control means 49 Attitude measurement means.

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification number Reference number in the agency FI Technical indication location H04N 5/38 H04Q 9/00 301 B (72) Inventor Hirose Motohisa Tobita-cho, Chofu-shi, Tokyo No. 19-1 Kashima Construction Co., Ltd. Technical Research Institute

Claims (5)

[Claims] 1. An image transmitting method for transmitting an output image of an image pickup device attached to a moving body moving on the ground surface from the moving body to a fixed station on the ground surface, wherein a radio wave signal of the output image of the image pickup device is sent to the moving body. A fixed directional transmitting antenna for transmitting in a predetermined direction on a moving body, a radio wave reflecting surface arranged to intersect the transmitting direction of the transmitting antenna, and a reflecting surface attitude control means for controlling the azimuth and elevation angle of a normal line of the reflecting surface. Attaching posture measuring means for measuring the posture of the moving body in the ground coordinate system,
The fixed station is provided with a directional receiving antenna, and the current transmitting azimuth and elevation angle of the transmitting antenna in the ground coordinate system are calculated from the posture of the moving body measured by the posture measuring means and the predetermined direction according to the movement of the moving body. The current transmission azimuth and elevation angle of the reception antenna in the ground coordinate system as viewed from the mobile body are calculated, and the radio wave signal incident from the current transmission azimuth and elevation angle of the transmission antenna is calculated as the current transmission azimuth and elevation angle of the reception antenna. Calculate the current normal azimuth and elevation angle of the reflection surface that is reflected toward, direct the reflection surface to the current normal azimuth and elevation angle, and calculate the current transmission azimuth and elevation angle of the transmitting antenna from the reflection surface of the reflection surface. This time, the reflection type image formed by transmitting the output image of the image pickup device from the moving body to the fixed station by repeating the cycle up to the normal azimuth and pointing to the elevation angle. Method Carriage. 2. The image transmission method according to claim 1, wherein a position measuring device based on a satellite navigation system is attached to the moving body, and the current position of the moving body measured by the position measuring device and the receiving antenna position of the fixed station are measured. From the above, a reflection type image transmission method in which the current transmission direction and elevation angle of the receiving antenna are detected. 3. The image transmission method according to claim 1 or 2,
A reflection-type image transmission method in which the transmission antenna is fixed vertically upward at an initial position where the moving body is parallel to the ground surface. 4. The image transmission method according to claim 1, 2 or 3, wherein the reflection surface is made of steel or aluminum. 5. The reflection type image transmission method according to claim 4, wherein the reflection surface is a convex reflection curved surface facing the transmission antenna.