JPS6315640B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a traffic signal control system that makes effective use of transmission lines.

BACKGROUND OF THE INVENTION In recent years, as traffic signals have been centrally controlled and various traffic terminals have been installed, the number of transmission lines for this purpose has also continued to increase, and effective and effective use of transmission lines is desired.

Currently, in the centralized control of traffic signals, as shown in FIG. 1, an electronic computer 1 in a traffic control center and a traffic signal 2 are directly connected through a transmission line 3, and real-time control and monitoring is performed. The effective transmission band for the transmission line 3 is generally the voice band (0.3 to 3.4 KHz), and code transmission at 100 bits/second is transmitted as command information from the center to the traffic light 2, and from the traffic light 2 to the center. For
Code transmission at 600 bits/second is performed in full-duplex communication mode. Therefore, the transmission band ranges from about 400Hz to 2600Hz, and the band above 2600Hz is an empty band.

The present invention provides a new full-duplex or half-duplex communication channel in the vacant band of the transmission line for centralized control of traffic signals, and allows multiple terminals to use this channel multiplexed in a time-division manner. , the additional device receives an interrupt request signal from the terminal when information to be transmitted from the terminal to the center is generated, and provides a function of notifying the center of this signal.

This will be explained below along with examples. In Figure 2, 1 is the central computer, 2 is the traffic signal controller, 3 is the transmission line, 4 is the additional device, and 5 is the 100 bits/second divided by the band splitter built in the additional device 4. , and a connection connecting the 600 bit/s signal to the traffic signal controller 2, 6 is a band splitter on the center side, and 7 is the 100 bit/s and 600 bits/s signal.
A connection 8 connects the band demultiplexer 6 and the computer 1 for a bit/second signal, and a connection 8 connects the band demultiplexer 6 and the computer 9 for a newly established 50 bit/second full-duplex channel band signal. This is the wiring to connect.

Reference numerals 101 to 104 are terminals whose purpose is to exchange information with the center computer 9 by utilizing new channels in a time-sharing manner, and FIG. 2 shows four terminals as an example. Note that there are two types of connections for connecting the terminal and the additional device 4: one is a data signal line, and the other is an interrupt request signal line.

Here, the code rate of the communication devices used by the terminals 101 to 104 is 50 bits/second, which is the same as the code rate of the transmitter/receiver used in the additional device 4, and its center frequency is also the reception A-CH (A - Channel),
Specified for transmission B-CH (B-channel).

FIG. 3 shows details of the additional device 4.
1 is a line terminal connected to the center, and has a 100 bit/sec line terminal for centrally controlling the traffic signal 2;
A 600 bit/second band signal as well as two 50 bit/second band signals are superimposed. 13 is a band demultiplexer which separates and combines 100 bits/second, 600 bits/second band signals and 50 bits/second band signals. 1
2 is a connection with the traffic signal 2, and the 100 bit/second band signal input from the terminal 11 is sent to the traffic signal 2 via the connection 12, and the 600 bit/second signal from the traffic signal 2 is sent via the connection 12. The band signal is output to terminal 11. 14 receives the switch selection code from the center, and selects the selection relays SW ₁ , SW ₂ ,
It is assumed that this is a receiving circuit that drives either SW ₃ or SW ₄ and is based on an A-CH of 50 bits/second. Reference numeral 15 is a transmitting circuit for encoding which switch has been selected and sending it back to the center as a confirmation signal via 50 bits/second B-CH. Terminals 16 to 19 are connected to the terminal.

FIG. 4 is a time chart showing the signals and operations of the embodiment. In the figure, A is the A-CH signal sent from the center to the additional device, B is the B-CH signal sent from the additional device to the center, C is the traffic data between the center and the terminal 101, and D is the additional device SW _1. , E and F are the operations of the additional devices r _1-1 and r _1-2 , G is the interrupt request from the terminal 104, H is the operation of the additional device SW ₄ , and R is the communication between the center and the terminal 104. The data are shown respectively.

Next, the operation will be explained.

When receiving circuit 14 receives the SW ₁ selection command code, relay SW ₁ is driven, contact SW _1-1 is closed,
The terminal connected to terminal 16 is selected. Further, even if the receiving circuit 14 receives a code for selecting which switch, the relay R1, _{which operates in common, opens the contacts r1-2 and} closes the contacts _r1-1 . Therefore, even if the contact SW _1-1 is closed, the terminal connected to the terminal 16 is not connected to the lower band duplexer 13.

On the other hand, when relay SW ₁ is driven, another contact SW _1-2 is closed, and when R ₁ is driven, contact r _1-1 is closed.

As is clear from Fig. 4, the operation duration of each contact r _1-1 and r _1-2 is a duration with sufficient margin for the time required to return the SW ₁ confirmation signal from the transmitting circuit 15. There is. Furthermore, it goes without saying that the return start time of the confirmation signal should be sufficiently delayed with respect to the operation start time of the contacts r _1-1 and r _1-2 . Therefore, contacts r _1-2 are closed again after the confirmation return of SW ₁ is completed, and the terminal connected to terminal 16 for the first time now receives 50 bits/second A, B-CH. Ownership rights will be granted and information exchange with the center will be possible. At this time, the transmitting circuit 15 in the additional device 4 is opened by the contact _r1-1 , but the receiving circuit 14 is connected between the terminal and the center.
It remains connected in parallel to the 50 bit/s channel. Here, if a specific code for starting the receiving circuit 14 is determined, it is possible to prevent erroneous starting due to data exchanged between the terminal and the center.

Now, when data communication between the terminal device connected to the terminal 16 and the center is completed, a switch release command is transmitted from the center to the additional device 4.

The receiving circuit 14 in the additional device 4 is always in a receiving system, so when it receives this open command, the relay
Terminal 10 connected to terminal 16 with SW ₁ open
1 is released from the additional device 4.

Now, in Figure 4, the center and the terminal 10
A case is illustrated in which an interrupt request signal is input to the terminal 23 from the terminal 104 connected to the terminal 19 of the additional device 4 during data communication between the two devices.

When an interrupt request signal is detected, the additional device 4 terminates data communication with the terminal 101 and sends data from the center.
When returning the SW ₁ release confirmation signal based on the SW ₁ release command, an interrupt request signal from the terminal 104 is sent to the center together with this code. Relay _R1 , which contributes to this series of operations, not only operates for a certain period of time when it receives a switch selection command from the center, but also operates for a certain period of time when it receives a switch release command after data communication has ended. To operate, an interrupt request signal can be sent to the center during this time together with a confirmation signal from the additional device.

When the center detects an interrupt request from a terminal 104, SW ₄ is used to call the terminal 104.
Send selection command to attached device.

Hereinafter, data communication will be performed using the same procedure as the operation based on the SW ₁ selection command.

Now, in the above explanation, the series of operations in the additional device 4 were performed when an interrupt request was received from another terminal while a certain terminal was communicating with the center, but when the terminal is not communicating with any terminal In other words, when the additional device 4 is in a standby state, the additional device 4 can immediately notify the center of interrupt information.

In the standby state, none of the terminals is communicating with the center, so switches SW ₁ to _{SW 4} are in the open state, r _1-1 is in the open state, and r _1-2 is in the closed state. There is. The receiving circuit 14 determines these standby states from the switches _SW1 to _SW4 and the common relay _R1 . Then, in the standby state, the terminal 101~
104 outputs an interrupt request signal to one of the terminals 20 to 23, the transmitting circuit 15 outputs the interrupt request signal to one of the terminals _{20 to 23} .
Close one of SW _4-2 to close switch SW ₁ . The receiving circuit 14 is a switch
Operate common relay R ₁ from the closed state of SW ₁ to r _1-1
to the closed state and r _1-2 to the open state. Then, the interrupt request signal is sent from the transmitting circuit 15 to _r1-1 , and the band demultiplexer 1
3. Output to the computer 9 via the transmission line 3. The computer 9 inputs this interrupt request signal, and thereafter the computer 9 receives the interrupt request signal via the transmission line 3.
The terminals 101 to 104 that have output the interrupt request signal are designated for data communication.

Further, the interrupt request signal from the terminal side is reset by a reset command from the center during information exchange with the center.

According to this embodiment, the transmission line can be used effectively, and since it has an interrupt function from the terminal side, information exchange between the terminal and the center is possible only by activation from the center. However, it is superior in that the center can be activated from the terminal side as well.

For example, when information that should be reported to the immediate center occurs on the terminal side, or when a serious failure occurs on the terminal side, the information can be notified to the immediate center, which is effective.

As is clear from the above examples, the present invention
In a system that controls traffic signal controllers via a transmission line with a transmission band of Hz to 3400Hz,
A 50-bit/second signal is superimposed on the vacant band from 2600Hz to 3400Hz, and data transmission between the terminal and the center is controlled by a switch and a common relay. This has the effect that the terminals can be used in common on the same transmission line, and the transmission line can be used effectively.

[Brief explanation of the drawing]

Fig. 1 is a block diagram of a conventional centralized control system for traffic lights, Fig. 2 is a block diagram of a traffic signal control system according to an embodiment of the present invention, Fig. 3 is a block diagram of additional equipment, and Fig. 4 is a block diagram of a traffic signal control system according to an embodiment of the present invention. FIG. 4 is an operation time chart of the additional device. 1...Electronic computer, 2...Traffic signal controller, 3
...Transmission line, 4...Additional device, 14...Reception circuit, 15...Transmission circuit.

Claims (1)

[Claims] 1. Transmission line 3, and the transmission line has a frequency of 300Hz to 3400Hz.
The first electronic computer 1 and the first electronic computer are
100 bit/s and 600 bit/s signals from 400Hz
It transmits and receives in a transmission band of 2600Hz, and the second computer 9 and the second computer
It transmits a 50 bit/second signal in a transmission band of 2600Hz to 3400Hz, and includes first and second band splitters 13 and 6, and the first
and the second band splitter separates the frequency into low frequency and high frequency with 2600Hz as the border, and the traffic signal controller 2 and the traffic signal controller have 100Hz.
bit/s and 600 bits/s signal from 400Hz to 2600
It transmits and receives in a transmission band of Hz and is controlled by the first electronic computer 1, and includes a plurality of terminals 101 to 104, and the terminals include 50
The terminal transmits and receives data signals of bits per second in a transmission band of 2600Hz to 3400Hz, and outputs an interrupt request signal, and the terminal detects the equipment status. inputs the signal of the second computer 9 and connects the terminals 101 to 104 designated by this signal to the second computer 9; The circuit detects that none of the plurality of terminals 101 to 104 is communicating with the second computer 9, and receives an interrupt request output from any one of the terminals 101 to 104. The signal is transmitted to the second electronic computer 9.
The first band splitter 13 is connected to each of the traffic signal controller 2, the plurality of terminals 101 to 104, the receiving circuit 14, and the transmitting circuit 15. One end of the transmission line 3 is connected to the subsequent stage, and the second end is connected to the other end of the transmission line 3.
A traffic signal control system characterized in that a band branching filter 6 is connected thereto, and the first and second electronic computers 1 and 9 are connected at a subsequent stage thereof.