JP3419571B2 - Remote monitoring device - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention moves on a track laid within a required range for monitoring a wide area in a plane. The present invention relates to a remote monitoring device that mounts a camera on a cart, captures an image of a monitoring area while moving, and remotely monitors the situation at the site. 2. Description of the Related Art Conventionally, for example, when monitoring shelves in a warehouse and monitoring the inside of a substation premises, an ITV camera is mounted on a mobile trolley, and a predetermined monitoring area is imaged while moving the trolley. A remote monitoring device for monitoring is used. FIG. 5 shows an example of the configuration of a remote monitoring device in a case where a truck moves linearly. In FIG. 5, reference numeral 1 denotes a truck on which an ITV camera 2 and a light transmitter 3 for photographing the state of the monitored place are mounted, and move on a track 4 laid linearly. The light transmitter 3 converts a signal photographed by the ITV camera 2 into an optical signal and transmits the optical signal to ground equipment. On the ground side, the optical signal transmitted from the light transmitter 3 is received by the light receiver 5 and the monitor TV installed in the monitoring room is received.
6 is output. [0004] As described above, the ITV camera 2 is mounted on the carriage 1 and the state of the monitored place is photographed while moving on the track 4. In the monitoring room, the state of the monitored place over a wide range can be constantly monitored by the monitor TV6. FIG. 6 shows an example of the configuration of a remote monitoring apparatus for monitoring an image over a wide area in a plane. In FIG. 6, reference numeral 10 denotes an area to be monitored which spreads in a plane, and the track 4 is laid around the area so as to form a rectangle. The trolley 1 on which the ITV camera 2 and the light transmitter 3 are mounted orbits in this track 4 in a certain direction as indicated by arrows. On the ground side, a plurality of, for example, four light receivers 5 receiving the optical signal from the light transmitter 3 around the orbit 4 are provided.
a to 5d are provided. The signals received by the light receivers 5a to 5d are input to a video switch 11 provided in the monitoring room. On the ground side, a bogie position detecting device 12 for detecting the position of the bogie 1 is provided. This cart position detecting device 1
2 detects the position of the cart 1 and outputs the position detection signal to the video switch 11. The image switch 11 sequentially selects the outputs of the light receivers 5a to 5d, which are assumed to be transmitting the image from the light transmitter 3, based on the detection signal of the carriage position detector 12, and outputs the outputs to the monitor TV6. I do. In the above configuration, the ITV camera 2 mounted on the trolley 1 moves the monitored area 1 with the trolley 1 traveling.
Photographs are sequentially taken within 0. The video signal captured by the ITV camera 2 is converted into an optical signal by the light transmitter 3 and transmitted to the ground equipment. This transmission signal is transmitted to the photodetectors 5a to 5d.
And selectively sent to the video switch 11. The image switch 11 sequentially selects the outputs of the light receivers 5a to 5d, which are assumed to be transmitting the image from the light transmitter 3, based on the detection signal of the carriage position detecting device 12, for example, as shown in FIG.
In the state (1), the output of the light receiver 5a is selected and output to the monitor TV6. As described above, the carriage 1 travels around the monitored area 10 so that the state of the monitored area 10 can be constantly monitored by the monitor TV 6. FIG. 7 shows the video signal output of the photodetectors 5a to 5d when the monitored area 10 having a planar spread is monitored by the ITV camera 2 mounted on the carriage 1 as in the case shown in FIG. It is configured to be connected by a bus-shaped transmission cable 13 and output to the monitor TV 6. In such a configuration, only the necessary light receivers are used so that the video signal outputs of the plurality of light receivers 5a to 5d do not collide on the transmission cable 13, and the other light receivers do not output signals. Control is required. For this reason, the detection signal of the bogie position detecting device 12 is sent to the photodetectors 5a to 5d via the control line 14, and the outputs of the photodetectors that are assumed to transmit the video signal are turned on, and the outputs of the other photodetectors are turned off. Thus, monitoring can be performed by the monitor TV6. [0008] In the case of monitoring an image of a region which is spread in a plane, a plurality of light receivers 5a to 5d are required.
In order to install the trolley, the trolley position detecting device 12 for grasping the position of the trolley 1 is required. In addition, a cable is individually wired between the light receivers 5a to 5d and the monitoring room as shown in FIG. 6, or a video signal is provided between the light receivers 5a to 5d and the monitoring room as shown in FIG. A control line 14 for controlling the light receivers 5a to 5d is required in addition to the cable for transmitting the light, and the device configuration is complicated. SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned circumstances, and in the case of monitoring a wide area in a plane, the image can be monitored following the movement of the carriage without detecting the position of the carriage. It is an object to provide a simple remote monitoring device. According to the present invention, a photographing device is mounted on a truck moving on a track laid in a range required to be monitored, and a monitoring area is photographed while moving to remotely monitor the truck. In the remote monitoring device, a light transmitter that outputs a video signal photographed by a photographing device mounted on the carriage as an optical signal, and a light that is installed on the ground side along the track and is output from the light transmitter A plurality of light receivers that receive signals and convert the signals into electric signals; and a modulator that is provided corresponding to each of the light receivers and outputs an output signal of the light receiver as a carrier signal of a different high-frequency channel. A demodulator that selects each channel from high-frequency signals transmitted from each modulator via a coaxial cable to demodulate a video signal, and detects a video signal from the signal demodulated by the demodulator.
Outgoing video signal detector and the above video signal detector
If no video signal is detected, the demodulator
Channel to the next channel in sequence, and
When the video signal is detected by the output unit, the demodulator receives
A channel selection section for fixing a channel; and a monitor TV for displaying a video signal demodulated by the demodulator, wherein the channel selection section includes a video signal detection section.
The channel being received by the demodulator based on the detection signal
At the time when the video signal of
The channel is changed to the next channel . The ITV camera mounted on the trolley sequentially captures images of the monitored area as the trolley travels, converts the video signal into an optical signal with a light transmitter, and transmits the optical signal to the ground equipment. The optical signal transmitted from the light transmitter is received by the light receiver of the ground device facing the light transmitter, converted into an electric signal, and transmitted to the modulator. The modulator of each terrestrial device converts the video signal received by the light receiver into a high frequency signal of a different channel assigned in advance and outputs the high frequency signal. The high-frequency signal output from each ground device is multiplexed by a coaxial cable and sent to the monitoring room device. In this case, the optical signal output from the light transmitter mounted on the bogie is basically received by one ground device, and a monitoring video signal is transmitted from one of the ground devices to the monitoring room device. Sent to In the monitoring room apparatus, signals of different channels are sequentially selected by a channel selector, and demodulated by a demodulator to determine the presence or absence of a video signal. If there is no video signal, the next channel is selected, and if a video signal is detected, the channel selection is fixed. The video signal of the fixed channel is sent to the monitor TV, displayed on the monitor, and monitored remotely. As described above, the surveillance video signal sent from the ground equipment to the monitoring room apparatus via the coaxial cable as the carriage travels is selected and processed by the channel selection unit, and is output from each ground equipment. Even if a high-frequency signal is multiplexed by a coaxial cable, it is displayed on a monitor TV without causing interference or the like. An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a block diagram showing a configuration of a remote monitoring device according to one embodiment of the present invention. This embodiment is an illustration for the case of monitoring a region of planarly spread raceway formed on linear combinations or curved around the monitored region is laid. And on this track, IT
The cart 1 on which the V camera 2 and the light transmitter 3 are mounted orbits. On the ground side, on the other hand, a plurality of ground units 21a, 2 which receive an optical signal from the light transmitter 3 around the orbit.
, 21n are provided. The above-mentioned ground equipment 21a,
.., 21n are constituted by a light receiver 22 for receiving an optical signal from the light transmitter 3 and a modulator 23. The light receiver 22 converts an optical signal sent from the light transmitter 3 into an electric signal and inputs the electric signal to the modulator 23. The modulator 23 converts a video signal output from the light receiver 22 into a signal of a high-frequency channel such as a VHF band and outputs the signal. The above ground devices 21a, 21b,..., 21n
2 perform modulation processing using carrier signals, that is, channels having different center frequencies f1, f2,... Fn, as shown in FIG. Multiplexed by the transmitted transmission cable, for example, the coaxial cable 27, and the monitoring room apparatus 3
Sent to 0. The monitoring room apparatus 30 comprises a demodulator 31, a monitor TV 32, a video signal detecting section 33, and a channel selecting section 34. The video signal detection unit 33 determines the presence or absence of a video signal from the demodulated signal of the demodulator 31 and outputs the determination result to the channel selection unit 34. The channel selection unit 34 selects the next channel for the demodulator 31 when the video signal detection unit 33 determines that there is no video signal, and fixes the channel selection when the video signal is detected. FIG. 3 shows the structure of the demodulator 31, the video signal detector 33, and the channel selector 34. The demodulator 31 includes a tuner 311, a VIF (video intermediate frequency) unit 312, a PLL circuit 313, an amplifier 3
14, the output of the VIF unit 312 is sent to the video signal detector 33, and the output of the channel selector 34 is
The signal is input to the LL circuit 313. The tuner 311 is
A high-frequency signal transmitted from the modulator 23 of the ground devices 21a, 21b,... Via the coaxial cable 27 is selected based on the control of the PLL circuit 313, converted to an intermediate frequency, and output to the VIF unit 312. This VI
The F unit 312 amplifies the intermediate frequency signal output from the tuner 311 and then demodulates the signal, and outputs the demodulated signal to the video signal detection unit 33. The video signal detecting section 33 determines the presence or absence of a video signal with respect to the output signal of the VIF unit 312,
The result of the determination is output to the channel selector 34. When the video signal detection unit 33 determines that there is no video signal, the channel selection unit 34
Output a control signal to select the next channel. Accordingly, the PLL circuit 313 changes the reception frequency of the tuner 311 so as to receive the next channel. Thereafter, the reception channels of the tuner 311 are sequentially changed until a video signal is detected.
When the video signal is detected by the video signal detection unit 33, the channel selection unit 34 fixes the reception channel. Then, the video signal output from the VIF unit 312 is sent to the monitor TV 32 via the amplifier 314 and displayed on the monitor. Next, the overall operation of the above embodiment will be described.
In FIG. 1, an ITV camera 2 mounted on a trolley 1
As the carriage 1 travels, the monitored area is sequentially photographed. A video signal captured by the ITV camera 2 is transmitted to a light transmitter 3
Are converted to optical signals and transmitted to the ground devices 21a, 21b,. The optical signals transmitted from the light transmitter 3 are transmitted to the ground devices 21a, 21b,.
Is received by the light receiver 22 of The light receiver 22 converts the received optical signal into an electric signal and outputs the electric signal to the modulator 23. Each modulator 2 of the ground equipment 21a, 21b,...
Reference numeral 3 converts the video signal input from the light receiver 22 into a high-frequency signal of a different channel assigned in advance and outputs the high-frequency signal. The high-frequency signals output from the ground devices 21a, 21b,... Are multiplexed by the coaxial cable 27 and sent to the monitoring room device 30. In this case, the optical signal output from the light transmitter 3 mounted on the truck 1 is basically received by one of the ground devices 21a, 21b,. A monitoring video signal is sent from one of 21b,. In the monitoring room device 30, the channel selection unit 3
In step 4, signals of different channels, that is, signals of frequencies f1 to fn are sequentially selected and demodulated, and the presence or absence of a video signal is determined by the video signal detection unit 33. If there is no video signal, the next channel is selected by the channel selection unit 34, and when the video signal is detected, the channel selection is fixed. The video signal of the fixed channel is sent to the monitor TV 32, displayed on the monitor, and monitored remotely. As described above, the monitoring video signal sent from the ground devices 21a, 21b,... To the monitoring room device 30 via the coaxial cable 27 as the carriage 1 travels is selected by the channel selection unit 34. Therefore, each ground equipment 21
are multiplexed by the coaxial cable 27 and are displayed on the monitor TV 32 without causing interference or the like. Next, an example of the arrangement of the ground devices 21a, 21b,... Will be described with reference to FIG. FIG. 4A shows an arrangement relationship between the ground equipment 21a and the ground equipment 21b. The light receiving ranges A and B show a state where the orbit 4 has an overlapping portion 40. In this overlapping portion 40, both the ground equipment 21a and the ground equipment 21b
And outputs a high-frequency signal having a video signal. The demodulator 31 only needs to receive one of the signals. When the light transmitter 3 mounted on the carriage 1 moves on the track 4 from the ground device 21a to the ground device 21b, the monitoring room device 30 searches for the next high-frequency signal when the reception of the ground device 21a ends, A high-frequency signal having a video signal sent from the ground device 21b is selected. FIG. 4B shows a case where the overlapping portion 40 is set small, but the same processing operation as that of FIG. 4A is performed. FIG. 4C shows an example in which the setting is made so that the dead zone 41 can be formed by eliminating the overlapping portion. When the dead zone 41 is provided in this way, the ground equipment 2
After the reception of 1a is completed, the video signal cannot be received while passing through the dead zone 41. Therefore, the ground devices 21a, 21b,
It is desirable to set the position of. As described above in detail, according to the present invention, in the case of monitoring a wide area in a plane,
By moving a truck equipped with a camera on a track,
When the light receiver that receives the optical signal transmitted from the transmitter on the trolley changes sequentially, the ground equipment transmits the monitoring video signal to the monitoring room equipment with high frequency signals of different frequencies,
Since the monitoring room equipment selects and demodulates the high-frequency signal including the video signal, the transmitter mounted on the bogie does not detect the position of the bogie and does not switch the operation of the ground equipment. The video signal sent from the device can be continuously monitored.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a block diagram showing a configuration of a remote monitoring device according to one embodiment of the present invention. FIG. 2 is a diagram showing an example of setting a frequency of a high-frequency output signal of each ground device in the embodiment. FIG. 3 is a configuration diagram showing details of a main part of the monitoring room device in the embodiment. FIG. 4 is a diagram showing an example of the arrangement of ground devices in the embodiment. FIG. 5 is a diagram showing an example of a conventional remote monitoring in a case where a camera is mounted on a truck that moves linearly and video monitoring is performed. FIG. 6 is a diagram showing an example of the configuration of a conventional remote monitoring device when monitoring a video image of an area that is spread in a plane. FIG. 7 is a diagram showing another example of the configuration of a conventional remote monitoring device in the case of monitoring an image having an area that is spread in a plane. [Description of Signs] 1 carriage 2 ITV camera 3 light transmitter 4 orbits 21a to 21n ground equipment 22 light receiver 23 modulator 27 coaxial cable 30 monitoring room equipment 31 demodulator 32 monitor TV 33 video signal detection unit 34 channel selection unit 311 Tuner 312 VIF unit 313 PLL circuit 314 Amplifier

Continuation of front page (58) Field surveyed (Int.Cl. ⁷ , DB name) H04N 7/18

Claims (1)

(57) [Claims] [Claim 1] Remote monitoring in which an imaging device is mounted on a truck moving on a track laid in a necessary monitoring range, and a monitoring area is captured while moving and remotely monitored. In the device, a light transmitter that outputs a video signal photographed by a photographing device mounted on the cart as an optical signal, and an optical signal installed on the ground side along the track and output from the light transmitter A plurality of light receivers that receive and convert the light signals into electric signals; and a modulator that is provided corresponding to each of the light receivers and outputs an output signal of the light receiver as a carrier signal of a different high-frequency channel. A demodulator for selecting each channel from high-frequency signals transmitted from the modulator via a coaxial cable to demodulate a video signal, and detecting a video signal from the signal demodulated by the demodulator;
A video signal detector that detects no video signal by the video signal detector.
In this case, set the demodulator's reception channel to the next channel.
The video signal is detected by the video signal detection section.
Output, a channel that fixes the demodulator's receive channel
Comprising a tunnel selector, and a monitor TV for displaying a video signal demodulated by the demodulator, the channel selection unit, the detection signal of the video signal detection unit
Of the channel being received by the demodulator based on the
When the signal is no longer received, the receiving channel of the demodulator
A remote monitoring device characterized by changing the channel to the next channel .