JP3419572B2 - 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 necessary range for monitoring, and a monitoring area is photographed while moving to remotely monitor. 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 channel control unit for detecting a channel transmitting a video signal from high-frequency signals transmitted from each modulator through a coaxial cable, and a control signal from the channel control unit.
Comprising a demodulator for demodulating a video signal of the channel by selecting more receiving channels, and a monitor TV for displaying a video signal demodulated by the demodulator, the channel
The control unit transmits signals from each of the modulators via a coaxial cable.
A tuner for receiving the transmitted high-frequency signal;
Means for successively switching the receiving channels of the
The received signal of each channel received by the tuner
A video signal detector that determines the presence or absence of a video signal
The determination result of the image signal detection unit is stored, and a channel having a video signal is stored.
A control signal for selecting a channel is output to the demodulator and the demodulation is performed.
Select the receiving channel of the controller, and
When there is no image signal, the video signal detection unit determines
Select another channel with video signal based on the result
And a control unit for outputting a control signal to the demodulator.
And features. 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, a channel for transmitting a video signal is selected from a plurality of channels transmitted from each of the modulators via a coaxial cable by a channel control unit, and a receiving channel of the demodulator is selected. decide.
The demodulator demodulates the signal of the channel selected by the channel control unit, outputs the demodulated signal to the monitor TV, and displays it on the monitor. Thus, the monitor video signal sent from the ITV camera of the moving cart is continuously monitored by the monitor TV. As described above, the surveillance video signal sent from the ground equipment to the surveillance room apparatus via the coaxial cable as the carriage travels is selected by the channel control unit, and the receiving channel of the demodulator is determined. Even if the high-frequency signals output from the respective terrestrial devices are multiplexed by a coaxial cable, they are demodulated by the demodulator and displayed on the 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 device 30 comprises a demodulator 31, a monitor TV 32, and a channel control unit 33. The channel control unit 33 sequentially selects high-frequency signals transmitted via the coaxial cable 27 to determine the presence or absence of a video signal, and controls the reception channel of the demodulator 31 according to the determination result. FIG. 3 shows the configuration of the demodulator 31 and the channel control unit 33. The demodulator 31 includes a tuner 311, a VIF (video intermediate frequency) unit 31
2, a PLL circuit 313 and an amplifier 314. The output of the channel control unit 33 is input to the PLL circuit 313. The PLL circuit 313 selects a reception channel of the tuner 311 based on a control signal given from the channel control unit 33, and stably holds the reception channel of the tuner 311 based on an intermediate frequency signal output from the VIF unit 312. . The tuner 311 is connected to the coaxial cable 27 from the modulator 23 of the ground equipment 21a, 21b,.
The channel is selected based on the control of the PLL circuit 313, converted to an intermediate frequency, and output to the VIF unit 312. The VIF unit 312 amplifies the intermediate frequency signal output from the tuner 311 and then demodulates the signal.
14 to the monitor TV 32. On the other hand, the channel controller 33 comprises a tuner 331, a VIF unit 332, a PLL circuit 333, a video signal detector 334, and a controller 335.
The tuner 331 selects a channel of a high-frequency signal transmitted from the modulator 23 of the ground devices 21a, 21b,... Via the coaxial cable 27 under the control of the PLL circuit 333, converts the channel into an intermediate frequency, and converts the channel into an intermediate frequency. Output to The VIF unit 332 includes the tuner 33
Amplify the intermediate frequency signal output from 1 and demodulate it.
The demodulated signal is output to video signal detection section 334.
The video signal detection unit 334 determines the presence or absence of a video signal with respect to the output signal of the VIF unit 332, and outputs the determination result to the control unit 335. After storing the result of the determination, the control unit 335 outputs a control signal to the PLL circuit 333 to select the next channel. Hereinafter, all the channels are sequentially selected and the presence or absence of a video signal is stored. By continuously performing this operation, the presence or absence of a video signal is monitored, and a signal for selecting a channel having the video signal is output to the PLL circuit 313 of the demodulator 31.
When the carriage 1 moves and the video signal disappears, the control unit 335 outputs a signal for selecting a channel having another video signal to the PLL circuit 313 according to the monitoring result. In the same manner, the control section 335 selects a certain channel of the video signal and fixes the receiving channel of the demodulator 31. Therefore, in this reception channel, the video signal output from the VIF unit 312 of the demodulator 31 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 ground devices 21a, 2a
The high-frequency signals transmitted from 1b,... Are input to the demodulator 31 and the channel control unit 33. The tuner 331 of the channel control unit 33 sequentially selects different channels, that is, high-frequency signals of frequencies f1 to fn, based on the control of the PLL circuit 333, and converts the high-frequency signals transmitted via the coaxial cable 27 to an intermediate frequency. The data is converted and output to the VIF unit 332. This VIF unit 332 is
The intermediate frequency signal output from the tuner 331 is amplified and then demodulated, and the demodulated signal is used as a video signal detector 334.
Output to The video signal detection unit 334 determines the presence or absence of a video signal with respect to the output signal of the VIF unit 332, and outputs the determination result to the control unit 335. Control unit 3
35 stores the above-described determination result, and then outputs the result to the PLL circuit 333.
Output a control signal to select the next channel. Hereinafter, all the channels are sequentially selected and the presence or absence of a video signal is stored. By continuously performing this operation, the presence or absence of a video signal is monitored, and a signal for selecting a channel having the video signal is output to the PLL circuit 313 of the demodulator 31.
When the carriage 1 moves and the video signal disappears, the control unit 335 outputs a signal for selecting a channel having another video signal to the PLL circuit 313 according to the monitoring result. In the same manner, the control section 335 selects a certain channel of the video signal and fixes the receiving channel of the demodulator 31. 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 surveillance video signal sent from the ground equipment 21a, 21b,... Selected demodulator 3
Since one reception channel is determined, each terrestrial device 21
are multiplexed by the coaxial cable 27, and are demodulated by the demodulator 31 and 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, when monitoring an image having a two-dimensionally wide area,
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,
The high-frequency signal including the video signal is selected by the channel control unit provided on the monitoring room device side and demodulated by the demodulator, so that the operation of the ground device can be switched without detecting the position of the bogie. Instead, it is possible to continuously monitor the video signal sent from the light transmitter mounted on the cart.

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 21 a to 21 n ground equipment 22 light receiver 23 modulator 27 coaxial cable 30 monitoring room equipment 31 demodulator 32 monitor TV 33 channel control units 311, 331 tuner 312 332 VIF units 313 and 333 PLL circuit 314 Amplifier 334 Video signal detection unit 335 Control unit

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

Claims (1)

(57) [Claims] [Claim 1] A remote monitoring system in which an imaging device is mounted on a truck moving on a track laid in a required monitoring range, and a monitoring area is captured while moving and remotely monitored. In the apparatus, a light transmitter that outputs a video signal photographed by a photographing device mounted on the carriage as an optical signal, and an optical signal that is 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 channel controller for detecting a channel transmitting a video signal from high-frequency signals transmitted from the modulator via a coaxial cable, and a receiving channel based on a control signal from the channel controller. Comprising a demodulator for demodulating a video signal of the channel by selecting the channel, and a monitor TV for displaying a video signal demodulated by the demodulator, the channel control unit, a coaxial cable from the respective modulator
Tuner that receives high-frequency signals transmitted through the
And the reception channel of the above tuner is switched sequentially
And the channel of each channel received by the tuner
Video signal detection to determine the presence or absence of a video signal with respect to the received signal
Output unit and the determination result of the video signal detection unit are stored.
The demodulator outputs a control signal for selecting a channel having a signal.
To select the receiving channel of the demodulator, and
If the video signal of the channel disappears,
Based on the discrimination result of the signal detection unit.
Control to output a control signal for selecting a channel to the demodulator
Remote monitoring apparatus characterized by comprising a part.