CN1477533A - Network distributed express highway monitoring system based on network interconnected protocol - Google Patents

Abstract

The network distributed express highway monitoring system based on internetwork protocol is a kind of equipment for simultaneously monitoring every monitored point on the express highway. The system has a bus virtual special-purpose data network formed from distributed monitoring data unit and monitoring computer which is set on every monitoring point, adopts transmission control protocol/internetwork protocol network protocol cluster and client/server mode and uses access network as communication platform, in which the distributed monitoring data unit is formed from network card, embedded industrial control machine, parallel processing board and communication control board, the embedded industrial control machine is series-connected with network card and vehicle parallel processing board, and the parallel processing board is respectively connected with communication control board.

Description

The network distribution type highway monitoring system of interconnection protocol Network Based

One, technical field

The present invention is a kind of device of monitoring each monitored point on the highway simultaneously, particularly a kind of interconnection protocol network distribution type supervisory system Network Based.

Two, background technology

Highway monitoring system realizes that with the one of people, car, Lu Rongwei harmony it is to wagon flow guiding, shunting and scheduling.This is to realize that by being positioned at airfield equipments such as wagon detector on the highway, weather detector, remote control camera, variable information board, variable speed-limit sign these are provided with the airfield equipment kind along the road numerous, and quantity can reach up to a hundred.

The target of supervisory system is by the various transport information of gathering, and according to traffic control strategy, reasonably uses the traffic scheduling scheme, guiding, restricting traffic stream, reduce the incidence of traffic hazard, shorten the time that suspends traffic because of accident, to improve the agility and the security of highway.

In this mode, along each watch-dog on road respectively by MODEM (modulator-demodular unit) through low rate channel independently, link to each other one to one with the MODEM that is positioned at Surveillance center, insert multi-serial-port card then, carried out the software processes of different aspects again by communication controller, server final and in the monitor network links to each other.

This mode adopts the ONU-OLT Access Network as transmission platform, can call at the enterprising line data of SDH backbone network.And ONU has the plate of multiple interfaces mode, easily links to each other with multiple airfield equipment.This compares with the PDH transmission platform of in the past PCM standard has advantage.But it seems that now its weak point also is tangible:

1. it is clear to lack unity and coherence, and the software tightness is poor.Communication controller faces various interface conditions, the line level that differs, all kinds of transmission protocol, and communication software had both related to high level, also took numerous and diverse physical layer interface programming into account, was difficult to guarantee the monitoring and the maintainability of software.System burden is very heavy, crashes easily.

2. wiring complexity is safeguarded inconvenience.All monitor data lines all will insert the MODEM and the multi-serial-port card of Surveillance center one by one, reach hundreds of, so need distributing frame, this can influence transmission quality again and often not use, so make wiring more complicated.

3. hardware reliability is poor, and circuit is many, and hard connector is also many, is prone to fault year in and year out, and easy care and scheduling do not detect simultaneously.

4. speed is slow, and real-time is poor.Control on Communication adopts and the pairing a few Kbps slow rates of watch-dog, and can only timesharing communicate by letter one by one with watch-dog.

5. with change equipment and active and standby switching, complicated wiring makes and increases very difficulty of equipment and active and standby switching.

Three, summary of the invention

1, technical matters

The purpose of this invention is to provide that a kind of wiring is simple, real-time good, easy to maintenance, interconnection protocol network distribution type highway monitoring system Network Based that reliability is high.

2, technical scheme

The network distribution type highway monitoring system of interconnection protocol Network Based of the present invention, it is characterized in that this system has formed the bus-type Virtual Data Network by the distributed monitoring data cell and the supervisory control comuter of each control point setting, adopt transmission control protocol/network interconnection protocol network protocol family and Client, with network unit/optical network terminal (ONU/OLT) Access Network as communications platform; Wherein, the distributed monitoring data cell is made up of network interface card, built-in industrial control machine, co-processing board, communication control panel, and built-in industrial control machine is connected with bus mode with network interface card, tool co-processing board, and co-processing board also joins with communication control panel respectively.

In the communication control panel, CPU element and mode switch unit join, the mode switch unit (connects level conversion unit, balance converting unit, software MODEM unit respectively, level conversion unit connects the outside by " RS232 " mouth, the balance converting unit connects the outside by " RS485 " mouth, and software MODEM unit connects external transmission lines by " MODEM " mouth.Among the present invention, communication control panel is formed by 0-15 number.

The hierarchical structure of this each communication terminal of system is respectively from top to bottom:

1. equipment outside the venue: data link layer, Physical layer;

2. DMDU: application layer, transportation level, network layer, data link layer, Physical layer;

3. supervisory control comuter: application layer, transportation level, network layer, data link layer, Physical layer.

In the distributed monitoring data cell, " P11,12,15 " of the CPU integrated circuit in CPU element end and " RXD, TXD " respectively with the mode switch unit in commutation circuit join, " R1OUT, R2OUT " end of the level shifting circuit in the level conversion unit connects commutation circuit in the mode switch unit respectively; " Half " end of " RE, DE " termination commutation circuit of the integrated circuit in the balance converting unit, " A, B " termination commutation circuit of integrated circuit; " Full " end of " DE, RE " termination commutation circuit of balance converter ic, " A, B " end branch of balance converter ic connects commutation circuit in addition.

3, technique effect

Because monitoring airfield equipment interface condition differs, transmission mode difference, transfer rate and transmission range do not wait, and has different transmission protocols.Compare with traditional centralized monitor mode, interconnection protocol network distribution type highway monitoring system Network Based has proposed a kind of new solution, the reliability and the real-time of highway monitoring system have been improved greatly, it is good to have maintainability performance simultaneously, advantage such as well arranged, real-time belongs to a major transformation of freeway monitoring system.

Its major advantage is embodied in the following aspects:

1. communication line is greatly simplified, and reliability significantly improves.Watch-dog is and connection corresponding one by one with the data collecting card that is positioned at DMDU by MODEM, and supervisory control comuter only needs a netting twine access ONU/OLT Access Network receive and send data.

2. part is firm, and maintainability performance is good.Data communication based on the optical networking of transmission control protocol/network interconnection agreement has ripe business software, and error correction capability is strong, system's stable and reliable operation.

3. well arranged, the equipment change is convenient.Monitor data at first enters DMDU and handles, and is sent to the center with consolidation form by optical networking then, and for Surveillance center, each watch-dog is the subaddressing of quite some DMDU only.

4. speed is fast, the real-time height.Monitor data is enclosed in DMDU in the network interconnection protocol data bag, in optical networking with the 10Mbps speed rates to Surveillance center, and can adopt parallel processing algorithm.

5. be equipped with the supervisory control comuter easy switching, its LAN (Local Area Network) in transmission control protocol/network interconnection agreement can be switched active and standby supervisory control comuter easily, reaches the supervisory system back-up processing.

With DMDU network-type communication controller supporting the communication line protective device can further improve protection to the access line road, system adopts the three-level protective design, and subscriber's line is played effective protective effect.

Four, description of drawings

Fig. 1 is a general structure synoptic diagram of the present invention;

Fig. 2 is the structured flowchart of distributed monitoring data cell among the present invention: network interface card 1, embedded control machine 2, co-processing board, co-processing board 3, communication control panel 4 are wherein arranged.

Fig. 3 is system hierarchy figure of the present invention;

Fig. 4 is a data link control procedure synoptic diagram;

Fig. 5 is the process structure synoptic diagram of concurrent connection-oriented server;

Fig. 6 is the electrical schematic diagram of distributed monitoring data cell (DMDU).

Five, embodiment

The network distribution type highway monitoring system that the present invention is based on network interconnection agreement has been formed the bus-type Virtual Data Network by the distributed monitoring data cell DMDU and the supervisory control comuter of each control point setting, adopt transmission control protocol/network interconnection protocol network protocol family and Client, with the ONU/OLT Access Network as communications platform; Wherein, distributed monitoring data cell DMDU is made up of network interface card 1, built-in industrial control machine 2, co-processing board 3, communication control panel 4, built-in industrial control machine 2 and network interface card 1, co-processing board 3 are connected with bus mode, and co-processing board 3 also joins with 0-15 signal communication control panel 4 respectively.CPU element 41 is joined with mode switch unit 42 in each communication control panel, mode switch unit 42 connects level conversion unit 43, balance converting unit 44, software MODEM unit 45 respectively, level conversion unit 43 connects the outside by " RS232 " mouth, balance converting unit 44 connects the outside by " RS485 " mouth, and software MODEM unit 45 connects external transmission lines by " MODEM " mouth.

The hierarchical structure of this each communication terminal of system is respectively from top to bottom:

1. equipment outside the venue: data link layer, Physical layer;

2. DMDU: application layer, transportation level, network layer, data link layer, Physical layer;

3. supervisory control comuter: application layer, transportation level, network layer, data link layer, Physical layer.

Among the distributed monitoring data cell DMDU, CPU integrated circuit D1 in the CPU element 41 " P11,12,15 " end and " RXD, TXD " respectively with mode switch unit 42 in commutation circuit S1-2, S2-2, S5, S6 join, " R1OUT, the R2OUT " end of the level shifting circuit D5 in the level conversion unit 43 meets commutation circuit S1-2, S2-2 in the mode switch unit 42 respectively; " Half " end of " RE, DE " the termination commutation circuit S6 of integrated circuit D6 in the balance converting unit 44, " A, B " termination commutation circuit S4-1, the S2-1 of integrated circuit D6; " Full " end of " DE, RE " termination commutation circuit S6 of balance converter ic D7, " A, B " end branch of balance converter ic D7 meets commutation circuit S1-1, S3-1 in addition.

In distributed monitoring data cell DMDU, it is " 89C51 " that PCU integrated circuit D1 adopts model, the model that commutation circuit S1, S2, S5, S6 adopt is " 485/422 ", the model that level shifting circuit D5 in the level conversion unit adopts is " MA202E ", the model of integrated circuit D6, D7 in the balance converting unit is " MAX1487E ", and the model of long process integrated circuit D1 is " 82C55A "

DMDU network service controller belongs to the equipment that supervisory control comuter (HOST) and remote terminal (RTU) carry out data communication.Upstream Interface adopts standard 10BaseT Ethernet interface, uses unshielded twisted pair to connect.Downstream interface is two kinds of digital interface and analog interfaces, selective use, and RTU links to each other with remote terminal, and RTU quantity is unrestricted.

Any main frame can receive the data of RTU all the time.And by the controlling mechanism between main frame, can control and have only a main frame sending data to RTU.And each passage can use different main frames, the conveniently debugging of new RTU stipulations.

The DMDU unit is by 16 communication control panels of as many as, built-in industrial control machine, HUB (data distribution remittance) plate, and network interface card constitutes.Communication control panel is responsible for the data acquisition and the transmission of watch-dog; Industrial computer is responsible for the arrangement of data and transmission (descending and each watch-dog coupling, up satisfy network interconnection protocol network agreement); The HUB plate guaranteed industrial computer can parallel processing from the low speed monitor data of each communication control panel; Network interface card satisfies network interconnection protocol network technical conditions, and monitor data enters the ONU/OLT Optical Access Network by network interface card and is transferred to Surveillance center outside the venue.This system response time is a second order of magnitude, and MTBF is better than 10,000 hours.

Communication control panel is made up of a Single Chip Microcomputer (SCM) system, and this plate has the communication pattern of synchronous/asynchronous.Single-chip microcomputer carries out serial ports and expands, and has finished multiple serial ports condition.Wherein RS232 interface and RS422 interface are supported the base band transmission of short distance and longer distance respectively, and MODEM supports remote frequency band transmission.The speed of serial communication is that 600/1200/4800/9600bps is adjustable.The plate address is by its slot position decision.

System hierarchy

A plurality of airfield equipments and DMDU finish multiple spot and any asynchronous, full-duplex communication; Realized client computer-server model communication between a plurality of DMDU and the supervisory control comuter.The hierarchical structure of each communication terminal is as follows:

1. equipment outside the venue: data link layer, Physical layer;

2. DMDU: application layer, transportation level, network layer, data link layer, Physical layer;

3. supervisory control comuter: application layer, transportation level, network layer, data link layer, Physical layer.

Physical layer:

At different transmission requirements, serial line interface is realized with different circuit modes, is comprised three kinds of modes such as unbalanced circuit, half balance circuit and balancing circuitry.

In the native system be main a kind of standard FSK MODEM (being software MODEM) flexibly that realized with the software approach.It replaces special IC hardware such as (ASIC) to realize the modulation and demodulation work of digital signal in the mode of working procedure.The modulating part of this MODEM adopts earlier the direct frequency modulation method that digital signal is changed into the signal of two kinds of different characteristic frequencies, then this signal is handled (realizing with software) through " staircase ", carries out filtering again, with produce corresponding simulating signal.In the demodulation part, to received simulating signal amplification, amplitude limit, shaping, sampling, adopt the method (realizing) of a kind of " subregion differentiation " then with software, it is correctly reverted to original digital signal.Use software MODEM, can make that the instrument volume is little, in light weight, power consumption is few, antijamming capability is strong.In addition software MODEM also have a hardware MODEM incomparable advantage, be exactly that it can support multiple standard, transfer rate and carrier frequency are variable, and this variation is very flexibly, and adjustment get final product only to need to do suitably to the correlation parameter in modulation and the demodulation process.

Monitor data adopts above several modes to transmit between airfield equipment DMDU; And between supervisory control comuter and DMDU, monitor data enters the ONU/OLT Optical Access Network by network interface card and transmits.

Data link layer:

Between DMDU and monitoring airfield equipment, adopt transmission mode asynchronous, full duplex, used character-oriented type transmission control procedure.These rules realize being easier to, and are still used in a large number at present.But shortcomings such as efficient is low, transparency difference that it also exists.Use the point-to-point asynchronous communication of character type transmission control procedure.

According to the general controls rules, the device fabrication merchant has set the control command and the transmission command of concrete equipment, forms specific transmission protocol.Different airfield equipments forms specific transmission protocol according to transmission protocol and DMDU separately.Different airfield equipments forms multiple spot communicating by letter to any according to transmission protocol separately with DMDU.Communication control panel is responsible for accepting/sending transparent character data; Industrial computer then is responsible for command conversion is become specific control character, and control character is interpreted as corresponding order.Industrial computer obtains monitor data from airfield equipment, make corresponding explanation, and then give application layer process with it.

DMDU and supervisory control comuter have been formed Ethernet, and Ethernet also is that the link level of machinery compartment connects, and it regards the data that are transmitted as a frame (frame).Ethernet frame is a variable-length.Each ethernet frame all comprises source and destination address field, and it also has a frame type field, is used for discerning the type of contained data on this frame.

Network layer and transportation level:

Network layer and transportation level have adopted two main agreements that are used for internetworking: network interconnection agreement and transmission control protocol agreement.Insecure, nothing connection delivery mechanism that network interconnection protocol has; The transmission control protocol protocol definition reliable stream delivery service.

Application protocol:

The communication message form that is encapsulated in the transmission control protocol message is as shown in the table:

	Type	2 bytes
			Sign	Identify	2 bytes
Sequence of message	Index	2 bytes
			Message length	Length	2 bytes
Effect and	Checksum	2 bytes
			Port numbers	Portno	2 bytes
Test serial number (optional)	Index	2 bytes
			Confirm result (optional)	Result	2 bytes
Data length (optional)	Length	2 bytes
			Data content (optional)	Data	The N byte
Effect and	Checksum	2 bytes

Data mainly contain following a few class transfer process: (the H=supervisory control comuter, D=DMDU)

(1) reads and accept buffer zone

The step1 request of reading (D-＞H)

Step2 reads and replys (H-＞D)

Step3 reads affirmation (D-＞H)

Step4 confirms to return (H-＞D)

(2) write the transmission buffer zone

Step1 writes request (D-＞H)

Step2 writes affirmation (H-＞D)

The communications applications of native system has been taked client computer-server model, and client computer-server model comes the application programs classification with the direction of initiating communication.When DMDU uses the network service in native system, call client software, initiate peer-to-peer communications.Server software in the supervisory control comuter is waited for and is gone into the call communication request from client computer.Server receives the request of certain client computer, carries out required calculating, and the result returns to client computer then.Although the bus-type Virtual Data Network in the system is not complicated internet, consider that the transmission control protocol agreement itself provides powerful reliability; Native system has used transmission control protocol to transport message between client computer and server.Because the data volume of several monitor datas is not very big in the system, supervisory control comuter has adopted stateless server.

In client computer-server model Distributed Calculation, concurrent processing is the basis, and occurs in a variety of forms.Server software adopts the mode of multi-process to handle a plurality of clients concomitantly to go into request in the native system.

Server processes not with the client computer direct communication.It just waits for next connection request on certain fixed port.In case have some connection requests to arrive, system just returns the new socket descriptor that is used for this connection.The server host process is created one and is handled this connection from process, and allows from the process concurrent operations.Use when avoiding etc. to be connected cpu resource, server host process to use the obstruction of accept (accept connect function) to call and obtain next the connection from fixed port.The most of the time of server host process is in accept and calls blocked state.When a tool connection request arrived, accept called just and returns, and made host process continue operation.Host process is created one and is handled request from process, and calls accept again.This will make server host process secondary stricture again before being invoked at another connection request arrival.

Claims (6)

1, a kind of network distribution type highway monitoring system of interconnection protocol Network Based, it is characterized in that this system has formed bus-type data private by distributed monitoring data cell (DMDU) and supervisory control comuter that each control point is provided with, it has adopted transmission control protocol/network interconnection protocol family and Client, with Access Network as communications platform; Wherein, distributed monitoring data cell (DMDU) is made up of network interface card (1), built-in industrial control machine (2), co-processing board (3), communication control panel 4, built-in industrial control machine (2) is connected with bus mode with network interface card (1), co-processing board (3), and disposable plates (3) is joined with communication control panel 4.

2, the network distribution type highway monitoring system of interconnection protocol Network Based according to claim 1, it is characterized in that in the communication control panel, CPU element (41) is joined with mode switch unit (42), mode switch unit (42) connects level conversion unit (43), balance converting unit (44), software MODEM unit (45) respectively, level conversion unit (43) connects the outside by " RS232 " mouth, balance converting unit (44) connects the outside by " RS485 " mouth, and software MODEM unit (45) connects the outside by " MODEM " mouth.

3, the network distribution highway monitoring system of interconnection protocol Network Based according to claim 1 and 2 is characterized in that communication control panel (4) forms by 0-15 number.

4, the network distribution type highway monitoring system of interconnection protocol Network Based according to claim 1 and 2 is characterized in that the hierarchical structure of this each communication terminal of system is respectively from top to bottom:

1. equipment outside the venue: data link layer, Physical layer;

2. DMDU: application layer, transportation level, network layer, data link layer, Physical layer;

3. supervisory control comuter: application layer, transportation level, network layer, data link layer, Physical layer.

5, the network distribution highway monitoring system of interconnection protocol Network Based according to claim 1 and 2, it is characterized in that in the communication control panel, " P11,12,15 " of the CPU integrated circuit (D1) in the CPU element (41) end and " RXD, TXD " respectively with mode switch unit (42) in commutation circuit (S1-2, S2-2, S5, S6) join, " R1OUT, R2OUT " end of the level shifting circuit (D5) in the level conversion unit (43) connects commutation circuit (S1-2, S2-2) in the mode switch unit (42) respectively; " Half " end of " RE, DE " the termination commutation circuit (S6) of the integrated circuit (D6) in the balance converting unit (44), " A, B " termination commutation circuit (S4-1, S2-1) of integrated circuit (D6); " Full " end of " DE, RE " the termination commutation circuit (S6) of balance converter ic (D7), " A, B " end branch of balance converter ic (D7) connects commutation circuit (S1-1, S3-1) in addition.

6, the network distribution highway monitoring system of interconnection protocol Network Based according to claim 1 is characterized in that with network unit/optical network terminal (ONU/OLT) as Access Network.

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