JP2003296864A - Remote monitoring system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To efficiently transmit data from individual observation devices to a monitoring device when a constitution is adopted in which the number of optical fibers is reduced by multi-point connections. <P>SOLUTION: In a remote monitoring system composed by multi-point connection at the observation devices 11-1 to 11-n to the monitoring device through a single-fiber optical fiber cable 15a, the observation devices 11-1 to 11-n are provided with a timing table 23. In the timing table 23, the time from the reception of calling signals to the transmission of response signals is registered. In the case that batch calling is performed from the monitoring device, the observation devices 11-1 to 11-n refer to the timing table 23 and return a response at a preset time interval. Thus, the need of the troublesome communication procedure of individually issuing a connection request, waiting for the response and then transmitting data or the like is eliminated and the data are efficiently transmitted. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a remote monitoring system for remotely monitoring the conditions of rivers, roads, dams, etc.

[0002]

2. Description of the Related Art Conventionally, a remote monitoring system as shown in FIG. 9 is known in order to collect the situation of rivers, roads, dams, prevent disasters and accidents, prevent expansion, and provide recovery support. ing.

This remote monitoring system comprises a plurality of observation devices 1a, 1b ... Installed in an observation area and a monitoring device 2 for remotely monitoring these observation devices 1a, 1b. The observation devices 1a, 1b ... And the monitoring device 2 are two optical fiber cables 3 that are divided into an upstream signal and a downstream signal.
They are connected point-to-point by a, 3b .... If the observation target is a river, for example, the observation devices 1a, 1b ... Are installed at predetermined intervals along the river, and data of a measuring instrument for measuring water quality, water level, etc. and video data of a monitoring monitor are converted into optical signals. It is converted and sent to the monitoring device 2. The monitoring device 2 has a function of converting an optical signal from each of the observation devices 1a, 1b ... To an electric signal to display image data on a monitor and outputting measurement data.

Further, the monitoring device 2 converts a control signal for controlling a measuring instrument or a monitoring camera into an optical signal and sends it to each of the observation devices 1a, 1b. Each observation device 1a, 1b
On the ... side, the control signal is converted into an electric signal to drive and control the measuring instrument, the monitoring camera, and the like, and transmit the requested data.

[0005]

In the above-mentioned remote monitoring system, since the plurality of observation devices 1a, 1b ... And the monitoring device 2 are connected point-to-point, the number of lines depends on the number of observation devices. However, there was a problem that it was not possible to flexibly cope with the increase of observation equipment.
In this case, for example, as disclosed in Japanese Patent Application No. 9-46280, the number of lines can be reduced by making a point-to-multipoint connection.
Each slave computer individually makes an inquiry to the master computer, waits for the response, and then sends the data, which causes a problem that a complicated communication procedure is required before sending the data. is there.

The present invention has been made in view of the above points, and efficiently transmits data from each observation device to a monitoring device when the number of optical fiber cores is reduced by multipoint connection. It is an object of the present invention to provide a remote monitoring system that is capable of performing

[0007]

A remote monitoring system of the present invention comprises a plurality of observation devices installed in an observation area, a monitoring device for remotely monitoring these observation devices, each of the observation devices and the above monitoring. It is composed of an optical communication network that connects the device at multiple points via a single optical fiber cable. The monitoring device includes calling means for transmitting a calling signal for collectively calling the observation devices connected to the optical communication network, and each observation device receives a response signal after receiving the calling signal. And a response means for transmitting a response signal when the time registered in the table means elapses, and each of the observation devices has a predetermined time interval. The registration time of the table means is set so as to transmit a response signal.

According to such a configuration, the number of optical fiber cores can be significantly reduced by connecting a plurality of observation devices and the monitoring device at multiple points via one optical fiber cable, and the observation can be performed. It is possible to flexibly respond to equipment expansion. Also, in such a multipoint connection, each observation device monitors the observation data by making a batch call from the monitoring device to each observation device and returning a response at a predetermined time interval in each observation device. When sending to a device, it is possible to efficiently send observation data at a predetermined time interval, without the need for complicated communication procedures such as individually issuing a connection request and waiting for the response before sending data. You can

[0009]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings.

(First Embodiment) FIG. 1 is a diagram showing a configuration of a remote monitoring system according to a first embodiment of the present invention. This remote monitoring system is for remotely monitoring the status of rivers, roads, dams, etc.
1-1 to 11-n (n is an integer of 2 or more), 12-
1-12-m (m is an integer of 2 or more), 13-1
13-k (k is an arbitrary integer of 2 or more) and a monitoring device 14 that remotely monitors these observation devices. In addition, this system uses observation devices 11-1, 12-1, 13-
It can be configured with only one.

Observing devices 11-1 to 11-n, 12-1 to
12-m, 13-1 to 13-k are installed at a predetermined interval in the observation area, for example, if the observation target is a river,
It has a function of converting measurement data such as water quality and water level and observation data such as river image data taken by a surveillance camera into an optical signal and transmitting the optical signal to the monitoring device 14. Monitoring device 14
Is installed in the monitoring center and collects observation data sent from each observation device and remotely controls each observation device.

Observing devices 11-1 to 11-n, 12-1 to
12-m and 13-1 to 13-k are divided into groups. Here, the observation devices 11-1 to 11-n are the first group, the observation devices 12-1 to 12-m are the second group, and the observation devices 13-1 to 13-k are the third group. Observation devices 11-1 to 11-n of the first group
The monitoring device 14 is connected at a multipoint by branching the one-core optical fiber cable 15a common to upstream / downstream by the optical couplers 16-1 to 16-n-1. Similarly,
The observation devices 12-1 to 12-m and the monitoring device 14 of the second group connect the one-fiber optical fiber cable 15b to the optical coupler 1.
7-1 to 17-m-1 are branched and connected at multipoints, and the observation devices 13-1 to 13- of the third group are connected.
k and the monitoring device 14 are connected at multipoints by branching the one-fiber optical fiber cable 15c by the optical couplers 18-1 to 18-k-1. The distance and the number of units that can be connected with the single-fiber optical fiber cables 15a, 15b, and 15c are
It is determined by the characteristics of the optical fiber, the characteristics of the light emitting element and the light receiving element.

FIG. 2 shows the structure of the observation device 11-1, and FIG. 3 shows the structure of the monitoring device 14. In addition, in FIG.
Although only the configuration 1-1 is shown, other observation devices have similar configurations.

As shown in FIG. 2, the observation device 11-1 is
A basic control unit 21 including a microprocessor, a timer 22 for measuring time, a timing table 23 that defines transmission timing, a transmission control unit 24 that performs transmission control under the basic control unit 21, and the like.

Further, the observing device 11-1 is, as a constituent element for realizing optical communication, a modulation process from a digital signal to an analog signal (for example, FSK: frequency-shif).
modulator 25 for performing t keying), demodulator 26 for performing demodulation processing from an analog signal to a digital signal, and an electric / optical converter (hereinafter referred to as E / O) 2 for converting an electric signal into an optical signal.
7, an optical / electrical converter (hereinafter referred to as O / E) 28 for converting an optical signal into an electric signal, and an optical coupler 29 for branching a transmission system and a reception system.

In such a structure, the observation data obtained from the observation equipment 30 such as a measuring instrument or a surveillance camera is modulated into an analog signal by the modulation unit 25, and E
/ O27, where it is converted to an optical signal. This optical signal is sent to the optical communication network via the optical coupler 29, and then sent to the monitoring device 14 via the optical coupler 16-1 and the optical fiber cable 15a which constitute this optical communication network.
On the other hand, the optical signal sent from the monitoring device 14 is given to the O / E 28 via the optical coupler 29, converted into an electric signal here, and then demodulated by the demodulation unit 26 into a digital signal. It is received by the transmission control unit 25. The upstream optical signal and the downstream optical signal may use the same wavelength or different wavelengths.

The monitoring device 14 has a structure as shown in FIG.

The monitoring device 14 includes a basic control unit 31 composed of a microprocessor, an operation unit (operation console) 32 for an operator to perform various operations, a timer 33 for measuring time, and an observation device for each group. It is provided with a paging control table 34 in which transmission timings of paging signals for collectively calling are defined, a transmission control unit 35 for performing transmission control under the basic control unit 31, and the like.

Further, the monitoring device 14 is, as a constituent element for realizing optical communication, a demodulation section 36 for performing a demodulation process from an analog signal to a digital signal, and a modulation unit for performing a modulation process from a digital signal to an analog signal. 37, a branch input / output unit 38 for inputting / outputting data, a line switching unit 39 for switching lines, and an O / E for converting optical signals into electric signals
40a-40c, E / O4 for converting electrical signals into optical signals
1a to 41c, optical couplers 42a to 42 corresponding to each line
c and is configured to perform transmission and reception of data to and from each observation device while switching the line in group units.

In such a configuration, for example, the signals transmitted to the observation devices 11-1 to 11-n of the first group are modulated into analog signals by the modulator 37, and the branch input / output unit 38 and the line switching unit 39. To the E / O 41a via. Then, after being converted into an optical signal by this E / O 41a and sent out to the optical communication network through the optical coupler 42a,
It is sent to the observation devices 11-1 to 11-n of the first group via the optical fiber cable 15a. On the other hand, the optical signals sent from the observation devices 11-1 to 11-n of the first group via the optical fiber cable 15a are transmitted by the optical coupler 4.
It is given to the O / E 40a via 2a and converted into an electric signal here, and then the line switching unit 39 and the branch input / output unit 38.
Is sent to the demodulation unit 36 via. And this demodulation unit 3
The signal is demodulated into a digital signal at 6 and then given to the transmission control unit 35.

It should be noted that the O /
If the E40a to 40c and the E / Os 41a to 41c are always in the operating state, there is a problem that light leaks from these converters and noise occurs during communication. In order to solve such a problem, when the line is switched by the line switching unit 39, only the converter corresponding to the current line is operated. Specifically, for example, when connecting lines to the observation devices 11-1 to 11-n of the first group, the basic control unit 31 outputs an operation control signal (not shown) to output O / Es 40a and E. Only / O41a is turned on and the other converters are turned off. This can prevent light from leaking from unused converters and noise.

Next, the operation of this system will be described.

The monitoring device 14 includes a plurality of observation devices 11-1 to 11-n and an observation device 12-1 installed in the observation area.
.About.12-m and observation devices 13-1 to 13-k are connected in multipoints in group units. Therefore, it is not possible to simultaneously transmit data from each observation device to the monitoring device within the same group. Therefore, in this system, each observation device returns a response at a predetermined time interval by using a collective calling method as shown in FIG. In FIG. 4, # 1 to #n indicate a plurality of observation devices belonging to the same group, and in the case of the first group, for example, they correspond to the observation devices 11-1 to 11-n.

Now, the observation devices 11-1 to 11-1 of the first group
Description will be made assuming a collective call to 11-n. The monitoring device 14 first transmits a lock signal via the optical fiber cable 15a. This lock signal is a signal for prohibiting data transmission of the observation device, and is transmitted a plurality of times (here, three times). Circled numbers in FIG. 4 represent the number of transmissions. The reason why the lock signal is sent multiple times is that, for example, when the observation device is communicating, it may not be received only once. The lock signal transmitted from the monitoring device 14 via the optical fiber cable 15a is branched by the optical couplers 16-1 to 16-n-1 and the observation device 1
1-1 to 11-n.

Next, the monitoring device 14 transmits a calling signal via the optical fiber cable 15a. This calling signal is a signal for calling all the observation devices at once, and is sent a plurality of times (here, three times) in the same manner as the lock signal. Monitoring device 14 to optical fiber cable 1
The call signal transmitted via 5a is transmitted to the optical coupler 16-
Observation devices 11-1 to 11-1 are branched at 1 to 16-n-1.
Given to each of 1-n.

When the observation devices 11-1 to 11-n receive the calling signal, the observation devices 11-1 to 11-n refer to the timing table 23 provided in each of them and refer to the timing table 23.
A response is returned to the monitoring device 14 according to the time registered in. Specifically, in each of the observation devices 11-1 to 11-n, the basic control unit 21 sets the timing table 23
The time registered in is read, the timer 23 confirms that the time has elapsed, and responds. In this case, as shown in FIG. 4, the registration time of the timing table 23 is set so that the observation devices 11-1 to 11-n transmit response signals at predetermined time intervals. The communication time T (time slot width) given to each of the observation devices 11-1 to 11-n is the same. In addition, the observation device 11-
The signals sent from 1 to 11-n at the time of response include the observation device 11-
Each of 1 to 11-n includes observation data such as a measuring instrument or a monitoring camera which is an observation target. These observation data are converted into an optical signal and the optical fiber cable 15
It is sequentially sent to the monitoring device 14 via a. Finally, the monitoring device 14 sends the unlock signal to the observation devices 11-1 to 11-n.
To end the batch call here.

The lock signal and the lock release signal may be omitted in a system in which the observation devices 11-1 to 11-n do not output a return signal only in response to a call from the monitoring device 14.

The same applies to the other groups, and the monitoring device 14 makes a collective call for each group. The timing at which the batch call is performed for each group is set in the call control table 34. The basic control unit 31 refers to the call control table 34 and makes a batch call in group units at a predetermined timing.

In this way, the observation device (11-1 to 11-n, 12-1 to 12-m, 13
-1 to 13-k) is configured to reduce the number of optical fiber cores by connecting multiple points, the monitoring device 14 calls each observation device at a time, and each observation device at a predetermined time interval. By sending a response, when each observation device sends observation data to the monitoring device, a troublesome communication procedure such as individually issuing a connection request, waiting for the response, and then transmitting the data is performed. Without needing
The observation data can be efficiently transmitted at a predetermined time interval.

In the first embodiment, the communication time of each observing device is fixed, but the timing table 23 is registered so that the communication time for an important observing device or an observing device having a large amount of data is lengthened. You may set the time beforehand. In this case, as shown in FIG. 5, each observation device transmits data at different communication times T1, T2 ... Tn.

Even if no call is made from the monitoring device 14, for example, in an emergency, each observing device can monitor the device 1.
It is also possible to issue a connection request to 4 to communicate. However, since there is only one line in the same group, connection requests may collide with other observation devices, and even if reconnection is performed at that time, connection requests collide with other observation devices again. There is a possibility that it will end up. As a method of avoiding such a problem, as shown in FIG. 6, when a connection request collides, a waiting time is randomly determined for each observation device, and reconnection is performed when different waiting times have elapsed. You may do it.

(Second Embodiment) Next, a second embodiment of the present invention will be described.

The second embodiment is characterized in that the observation device and the monitoring device are provided with a call function and a call switching function, and a voice signal for call and a data signal for observation are switched and sent.

The system configuration is the same as that of FIG. 1, and the observation devices 11-1 to 11-n, 12-1 to 12-m, 13-1.
13-k are divided into groups, and each group is multipoint-connected with the monitoring device 14.

FIG. 7 shows an observation apparatus 1 as a second embodiment.
It is a block diagram which shows the structure of 1-1. In addition, in FIG. 7, only the configuration of the observation device 11-1 is illustrated, but other observation devices have the same configuration. Further, the same parts as those in FIG. 2 are designated by the same reference numerals, and the description thereof will be omitted.
The difference from FIG. 2 is that a call section 51 and a call switching section 52 are added to the observation device 11-1.

The call section 51 is composed of a transmitter and a receiver, inputs and outputs voice signals, and is used when a call is made with the monitoring device 14 as a communication partner.
The call switching unit 52 has a function of switching the voice signal input from the call unit 51 and outputting the voice signal to the E / O 27. Also,
A voice signal from the observation device 14 is given to the call unit 51.

FIG. 8 shows a monitoring device 1 as a second embodiment.
4 is a block diagram showing the configuration of FIG. The same parts as those in FIG. 3 are designated by the same reference numerals, and the description thereof will be omitted. The difference from FIG. 3 is that a call section 61 and a call switching section 63 are added to the monitoring device 14.

The call section 61 is composed of a transmitter and a receiver, and inputs and outputs a voice signal. The observation devices 11-1 to 11-n and 12-1 to 12-m are communication partners.
It is used when making a call with 13-1 to 13-k. The voice signal from the observation device is given to the call unit 61. The call switching unit 63 has a function of switching the voice signal input from the call unit 61 and outputting it to the branch input / output unit 38.

It should be noted that the telephone call is not used during transmission / reception of a data signal.

In such a configuration, the monitoring device 14 has the observation devices 11-1 to 11-n, 12-1 to 12-m, 1
When performing observation control of 3-1 to 13-k,
Similar to the embodiment described above, by collectively calling from the monitoring device 14 in units of groups, each observation device receiving the calling signal connects to the monitoring device 14 at a predetermined time interval and returns a response signal. This response signal includes observation data from measuring instruments and surveillance cameras.

Here, each of the observation devices 11-1 to 11-n,
12-1 to 12-m, 13-1 to 13-k and monitoring device 1
The call to and from the mobile terminal 4 can be made only when the data signal for monitoring is not transmitted or received. In this case, wavelength division multiplexin (WDM)
g) method, from monitoring device 14 to each observation device 11-
1-11-n, 12-1-12-m, 13-1-13-
signal transmitted to k and each of the observation devices 11-1 to 11-n, 1
2-1 to 12-m, 13-1 to 13-k to monitoring device 1
4 by changing the wavelength of the transmission signal to
4 and each observation device 11-1 to 11-n, 12-1 to 12-
A two-way call is possible between the m and 13-1 to 13-k.

As described above, in the second embodiment, when the observation devices are multipoint connected, the voice signal for communication and the data signal for observation are switched to be sent. It is possible to make a call using a voice signal.

It should be noted that the point through one optical cable
In the optical communication network connected by two-point multi-point, E / which converts the modulated signal which is the output signal from the modulator 25 in FIG. 2 or the call voice signal from the call unit 51 in FIG. 7 into light
In order to avoid collision in the optical communication network, the O27 and the E / Os 41a to 41c for converting the modulated signal which is the output signal from the modulator 37 in FIG. 3 or the call voice signal from the call unit 61 in FIG. In general, the input signal level is configured to modulate and emit light at a certain level or more. However, a transmission control signal indicating the transmission state of the modulation signal or the call voice signal is defined in FIG. Alternatively, a transmission control signal 70 may be added as shown in FIG. 7, or transmission control signals 71, 72a to 72c, 73a as shown in FIG. 3 or FIG.
By adding .about.73c, the mechanism for detecting the input signal level becomes unnecessary.

The transmission control signal is transmitted to E / Os 41a to 41c.
By inputting (FIG. 3 or FIG. 8) and performing multiplex transmission, it is received and demodulated by the O / E 28 (FIG. 2 or 7) and extracted as a reception control signal 74. This reception control signal 74
Indicates that a signal is being received. Therefore, by using the signal for controlling the power supply of the receiving unit in each observation device, it is possible to reduce the power consumption during standby of each observation device.

The control signal is transmitted from each observation device to the monitoring device by inputting the control signal at E / O 27 (FIG. 2 or FIG. 7) and performing multiplex transmission, or by O / O 27
The signals are received and demodulated at E40a to 40c (FIG. 3 or 8) and taken out as reception control signals 75a to 75c.

Here, in order to avoid a collision in the optical communication network, it is possible to know the timing at which a call can be made when data is not being transmitted by monitoring the reception control signals 74, 75a to 75c.

[0047]

As described in detail above, according to the present invention, the number of optical fiber cores is reduced by connecting a plurality of observation devices and monitoring devices at multiple points via one optical fiber cable. At the same time, the observation device makes a batch call to each monitoring device, and each observation device returns a response at a predetermined time interval, so that a troublesome communication procedure between each observation device is unnecessary. As a result, the observation data of each observation device can be efficiently transmitted to the monitoring device.

[Brief description of drawings]

FIG. 1 is a diagram showing a configuration of a remote monitoring system according to a first embodiment of the present invention.

FIG. 2 is a block diagram showing a configuration of an observation device in the remote monitoring system.

FIG. 3 is a block diagram showing a configuration of a monitoring device in the remote monitoring system.

FIG. 4 is a timing chart for explaining a data transmission procedure in the remote monitoring system.

FIG. 5 is a timing chart when the communication time of each observation device in the remote monitoring system is changed.

FIG. 6 is a diagram for explaining a standby method of each observation device in the remote monitoring system.

FIG. 7 is a block diagram showing a configuration of an observation device according to a second embodiment of the present invention.

FIG. 8 is a block diagram showing a configuration of a monitoring device according to a second embodiment of the present invention.

FIG. 9 is a diagram showing a configuration of a conventional remote monitoring system.

[Explanation of symbols]

11-1 to 11-n ... Observation device 12-1 to 12-m ... Observation device 13-1 to 13-k ... Observation device 14 ... Monitoring device 15a to 15c ... Optical fiber cable 16-1 to 16-n-1 ... Optical coupler 17-1 to 17-m-1 ... Optical coupler 18-1 to 18-k-1 ... Optical coupler 21 ... Basic control unit 22 ... Timer 23 ... Timing table 31 ... Basic control unit 33 ... Timer 34 ... Call control table 52 ... Call switching unit 53 ... Call switching section

   ─────────────────────────────────────────────────── ─── Continued front page    F term (reference) 2F073 AA01 AA40 AB02 AB03 AB12                       BB06 BC04 CC01 DD05 DD06                       DE01 DE14 DE16 FF09 FG03                       FH01 GG01 GG07                 5C054 CE12 CH01 DA01 DA10 FA09                       HA19                 5K048 BA35 CA06 DA02 DC08 EA23                       EB02 EB10 EB14 EB15 FA07                       HA01 HA02

Claims (3)

[Claims] 1. A plurality of observation devices installed in an observation area, a monitoring device for remotely monitoring these observation devices, and each of the observation devices and the monitoring device via a single optical fiber cable. The monitoring device comprises a calling means for transmitting a calling signal for collectively calling each of the observation devices connected to the optical communication network. Comprises a table means in which the time from the reception of the calling signal to the transmission of the response signal is registered, and a response means for transmitting the response signal when the time registered in the table means has elapsed, A remote monitoring system characterized in that the registration time of the table means is set so that each of the observation devices transmits a response signal at a predetermined time interval. 2. A plurality of observation devices installed in an observation area, a monitoring device for remotely monitoring these observation devices, and each of the above observation devices are divided into groups, and each of the observation devices and the above The monitoring device comprises an optical communication network that is connected to the monitoring device at a multipoint via a single optical fiber cable, and the monitoring device collectively calls the observation devices connected to the optical communication network in group units. The observation device has table means in which the time from the reception of the call signal to the transmission of the response signal is registered, and the time registered in the table means. And a response means for transmitting a response signal when the time elapses, and the registration time of the table means is set so that each observation device transmits the response signal at a predetermined time interval. Remote monitoring system, characterized by being. 3. The observation device and the monitoring device each include switching means for switching and transmitting a voice signal for communication and observation data. Remote monitoring system.