CN1777280A - Video monitoring method for small hydropower station telemechanical system in narrowband network - Google Patents

Abstract

The invention relates to a video monitoring-controlling method for small hydraulic power plant under narrow-band network. The monitoring-controlling system comprises host machine, camera, cradle head, video collection card, network card and modem. The monitoring-controlling method includes: 1.collect video data flow; 2.net-band dial and network connection; 3.set up the network connection with servo; 4.maintenance of picture frame column; 5.computing the rectangular matrix Tmin of variable zone; 6.compress the grating picture of variable zone; 7.asynchronous SOCKET transmission of compressed picture of variable zone; 8. decompress the grating picture of variable zone; 9.restoring the present picture frame C'. Advantages: realized remote collection of large amount of data and good data transmission reliability.

Description

A kind of video frequency monitoring method of small hydropower station telemechanical system in narrowband network

(1) technical field

The present invention relates to a kind of video frequency monitoring method of small hydropower station telemechanical system in narrowband network.

(2) background technology

In small hydropower station power remote monitor system, only there is data acquisition can not reach monitoring effect preferably, therefore monitor the situation of on-the-spot operation by real-time video, can greatly improve the monitoring effect of telecontrol system.Some specific positions such as dam, delivery port if carry out the personal monitoring, are not only wasted the great amount of manpower resource simultaneously, also have many unsafe hidden danger.Therefore, there is certain danger in these, and the place that disperses very much, if can adopt the long-distance video technology that it is carried out centralized monitor, then the problems referred to above all can be well solved.In small hydropower station power remote monitor system, video monitoring system mainly is responsible for the place abominable to some remote places (as: dam, delivery port, reservoir etc.), environment (as hydraulic turbine machine room etc.) and Central Control Room, main power house etc. and is monitored, and video signal transmission to a fixing place concentrated supervision, the individual historical video that is monitored the place of real time record is prepared against and is checked afterwards simultaneously.

Video monitoring system generally comprises: the cleaning of the remote transmission of this locality preservation of the collection of on-the-spot real time video signals, the compression of vision signal and coding, vision signal, network connection management, vision signal, the long-range demonstration of vision signal, cradle head control, historical video playback, access control, Qos control, history file and log record or the like.Associated hardware device generally comprises video monitoring main frame, gamma camera, The Cloud Terrace, video frequency collection card, network interface card and MODEM or the like.

Video monitoring system need realize the remote transmission to vision signal, and is because the data volume of vision signal is very big, very high to the requirement of the network bandwidth.The mountain area of small hydropower station remoteness, communication is inconvenience very, its all only depend on telephone wire to carry out with communicating by letter of the external world.Simultaneously, because the circuit question of telephone wire, often these regional telephone lines can't load the adsl carrier signal, perhaps this area does not open the ADSL service as yet, therefore can only carry out digital communication by the form and the external world of traditional Dial-up Network, promptly need in traditional PSTN network, to realize the digital video transmission of high amount of traffic amount.Obviously, traditional PSTN network is to transmit with common video transmission method, therefore need be optimized and handle with special method it, transmits again.The arrowband online adopts point-to-point Dial-up Network to be connected into Internet by MODEM.PPP comprises following three parts: (1) encapsulates the method for IP datagram on serial link.PPP had both supported that data are the asynchronous mode of 8 and no odd-even check, also supported bit-oriented synchronization links.The LCP of (2) foundation, configuration and tests data-link (LCP:Link Control Protocol).It allows communicating pair to hold consultation, to determine different options.(3) at Network Control Protocol (NCP:NetworkControl Protocol) system of heterogeneous networks layer protocol.RFC 1548 has described the method and the LCP of message encapsulation.RFC1332 has described the Network Control Protocol at IP.Narrowband network carries out the PPP dial-up connection by the RAS AP services I of Windows system, and relies on the dynamic-dns name server to carry out the dynamic IP location.

Still image compression standard JPEG (Joint Photographic Experts Group), it is joint image art expert group, be that International Standards Organization (ISO), 3 international organizations of CCITT (CCITT) and International Electrotechnical Commission (IEC) cooperate, finished in 1991 by.JPEG is the standard of ISO, also is the proposed standard of CCITT, and its target is the static colour picture data of compression, is used for the transmission and the storage of satellite, news picture more, and aspects such as figure, the processing of image documents and materials.The method that often adopts the figure frame to gather and transmit in existing arrowband method for supervising, the figure frame that directly will collect compresses by the still image compression algorithm.Though can greatly reduce the data volume of raster pattern like this, still can not utilize the historigram frame to carry out the cutting of image.

In order to guarantee that client has enough flexibilities, the narrowband service device has adopted client mode initiatively to carry out the transmission of video pictures, and promptly transmission course is initiated by client.After client is connected to server, at first send a transmission request that has the video channel number of needs transmission to server, after server receives request, will resolve the content of this request, if the video channel number in the request is (scope that does not exceed the effective video passage) effectively, then the image in the intercepting current video stream in the data flow of corresponding video channel transmits after overcompression again.

(3) summary of the invention

For the line bandwidth that is subjected to of the video frequency monitoring method that overcomes existing small hydropower station telemechanical system in narrowband network limits, can't realize the video acquisition of big data quantity, the deficiency of data transmission credibility difference with common video transmission method; The invention provides a kind of video frequency monitoring method of the small hydropower station telecontrol system that remote collection, the data transmission credibility of realization big data quantity is good in the current environment of narrowband network.

The technical solution adopted for the present invention to solve the technical problems is:

A kind of video frequency monitoring method of small hydropower station telemechanical system in narrowband network, this video monitoring system comprises video monitoring main frame, video camera, The Cloud Terrace, video frequency collection card, network interface card and modulator-demodulator, this video frequency monitoring method may further comprise the steps:

(1), the collection of video data stream: start video camera, video frequency collection card is sampled to the vision signal of video camera by the mode of sampling, encoding video signal and compression to sampling obtains are converted into digital video frequency flow, extract raster pattern frame C from video flowing;

(2), narrowband dialing is connected with network: adopt point-to-point Dial-up Network to be connected into Internet by modulator-demodulator;

(3), foundation is connected with the network of server: after the connection of client and server was set up, server adopted the mode of username and password that the legitimacy of the client of access is verified;

(4), the maintenance of figure frame queue: the video figure frame C that will at every turn extract by extraction time order be saved in the figure frame queue, the formation total length is L (Q), but the figure frame length of the current computing of formation is AL (Q), is limited to ML (Q) on the queue length; The figure frame queue adds current figure frame C, when L (Q)＞ML (C), and the figure frame of deletion formation stem;

(5), calculate region of variation rectangular matrix T _Min: traversing graph frame queue Q, calculate the difference degree vector Diff of each element among current figure frame C and the historigram frame vector H ^T, calculate region of variation rectangular matrix T _Min

(6), compression variation zone raster pattern: with region of variation rectangular matrix T _MinBe converted to raster pattern C ₁, utilize jpeg image compression algorithm compression raster pattern C ₁, obtain compressed image J; Simultaneously, with the tail end of the current raster pattern C adding figure frame queue Q that collects;

(7), the asynchronous SOCKET transmission of region of variation compressed image: be connected between video controlled terminal and the video server, J is transferred to video server with compressed image;

(8), decompress(ion) region of variation raster pattern: will utilize the image J after the jpeg image compression algorithm is compressed to be converted to raster pattern C ₂, with raster pattern C ₂Be converted to region of variation rectangular matrix T _s

(9), the current figure frame C ' of reduction: traversing graph frame queue Q, the figure frame H of the corresponding sequence number of taking-up from formation _i, with the region of variation matrix T _sRevise figure frame H _i, obtain current figure frame C '.

Further, described (5) may further comprise the steps:

(5.1), traversing graph frame queue Q, take out vectorial H=((σ _{I＜L (Q)}(Q)) ∩ (σ _{I＞AL (Q)}(Q _i))) ^T

(5.2), calculate the difference degree vector Diff of each element among current figure frame C and the historigram frame vector H ^T, difference degree computing function is: ${\mathrm{Diff}}_k=\underset{j=1}{\overset{\mathrm{width}\left(C\right)}{\mathrm{\Σ}}}\underset{i=1}{\overset{\mathrm{heighi}\left(C\right)}{\mathrm{\Σ}}}\mathrm{abs}(\mathrm{pix}(C,i,j)-\mathrm{pix}(H_k,i,j));$

(5.3), from vectorial Diff ^TIn find out minimum value Diff _Min=min (Diff ^T), Diff _MmSequence number be k;

(5.4), calculate region of variation rectangular matrix T _Min=σ _{Diff ≠ 0}(Diff _Min).

Further again, described (6) may further comprise the steps:

(6.1), with region of variation rectangular matrix T _MinBe converted to raster pattern C ₁, and

$\left\{\begin{array}{c}\mathrm{width}\left(C_1\right)\←\mathrm{width}\left(T_{\min }\right)\\ \mathrm{height}\left(C_1\right)\←\mathrm{height}\left(T_{\min }\right)\end{array}\right.;$

(6.2), utilize jpeg image compression algorithm compression raster pattern C ₁, obtain compressed image J; Simultaneously, with the tail end of the current raster pattern C adding figure frame queue Q that collects.

Further, described (7) may further comprise the steps:

(7.1), TCP is connected between video controlled terminal and video server;

(7.2), compressed image J is stored in the data flow, and be divided into piece smaller or equal to 1024 byte-sized;

(7.3), by asynchronous SOCKET, with the video server that is transferred to of each data block order;

(7.4), video server after receiving all data blocks, connect each data block according to transmission sequence again, be assembled into compressed image J.

Described (8) may further comprise the steps:

(8.1), will utilize the image J after the jpeg image compression algorithm is compressed to be converted to raster pattern C ₂

(8.2), with raster pattern C ₂Be converted to region of variation rectangular matrix T _s, and $\left\{\begin{array}{c}\mathrm{width}\left(T_s\right)\←\mathrm{width}\left(C_2\right)\\ \mathrm{height}\left(T_s\right)\←\mathrm{height}\left(C_2\right)\end{array}\right..$

Described (9) may further comprise the steps:

(9.1), traversing graph frame queue Q, from formation, take out the figure frame H of corresponding sequence number _i

(9.2), with the region of variation matrix T _sRevise figure frame H _i, obtain current figure frame C ', promptly

$\left\{\begin{array}{c}{C^{,}}_{\mathrm{kj}}=\mathrm{pix}(T_s,k,j)+\mathrm{pix}(H_i,k,j)\\ k=1\·\·\·\mathrm{height}\left(H_i\right)\\ j=1\·\·\·\mathrm{width}\left(H_i\right)\end{array}.\right.$

In described (1), when video frequency collection card collection and coding, compress what a complete frame of video after, come receiving video data stream by the function in the form caller of call back function immediately.

In described (2), narrowband network carries out the PPP dial-up connection by the RAS AP services I of Windows system, and relies on the dynamic-dns name server to carry out the dynamic IP location.

In described (3), server regularly sends a test data to client, if client receives this test data, then sends it back a feedback, if server is not received feedback in a period of time after sending test massage, think that then this connection disconnects unusually.

After server detects client and connected disconnection unusually, then clear up this connection; When new client connects access, reactivate this connection.

Operation principle of the present invention is: small power station is positioned at remote mountain area, geographical position mostly, and is simpler and cruder with the communication line that the external world is mutual, uses the telephone wire of common public switch telephone network to get in touch mostly.Program controlled telephone machine circuit based on PSTN (public switch telephone network) has following characteristics: 1, the restriction of communication line bandwidth can only have the transmission speed of 33.6kbps, therefore can be very restricted for long-range message transmission rate.2, PSTN communication line instability, the transfer bandwidth fluctuation is bigger, is difficult to guarantee long reliable and stable transfer of data.These two characteristics make power remote monitor system of small power station to rely on insecure slow network to be connected between two high-speed local area networks in control station, cities and towns and mountain area power plant.Therefore the realization of remote video monitoring, equipment scheduling is all very difficult.

On the basis that video controlled terminal vision signal real time flow medium is gathered, regularly from buffering area, generate the static map frame.And produce the figure frame queue and preserve the historigram frame, can compare with the historigram frame when making the current figure frame of transmission, to calculate minimum region of variation rectangle.Obtain minimum change zone raster pattern through cutting and adopt the compression of JPEG still image compression algorithm, further reduce its size.Utilize asynchronous SOCKET to transmit the compressed image of region of variation again in network, adopt time-division multiplexing (TDM) in the transmission, promptly a plurality of surveillance equipments only transmit the image of an equipment simultaneously.By the time the video server termination harvests behind the region of variation according to the historigram frame again and reduces current figure frame.After finishing video monitor, carry out control operations such as cradle head control.

The present invention proposes a kind of method that realizes the long-distance video collection of big data quantity, intelligent cutting, compression, transmission, decompress(ion) in the narrowband network communication environment, can reduce volume of transmitted data from the historical video information that minute utilization has been transmitted.Simultaneously, can also reserve the part bandwidth for other policer operations what carry out video transmission.This method is the characteristic pattern frame with the streaming media video conversion of signals, and storage historigram frame, can compare with the historigram frame when making the current figure frame of transmission, cutting obtains minimum region of variation raster pattern, adopt the still image compression afterwards, in Network Transmission, adopt time-division multiplexing (TDM), by the time the video server termination is received behind the region of variation according to the historigram frame again and is reduced current figure frame, thereby on the basis of normal static picture compression, reduced volume of transmitted data, increased real-time than direct use Streaming Media transmission.The present invention is fit to be applied to the video monitoring of small hydropower station telecontrol system, can utilize the narrowband dialing function of surfing the Net of public switch telephone network, realizes that in less bandwidth the real-time of video effect shows, can adapt to the region characteristic of small hydropower station.In the present invention, part steps has adopted existing technology and method, comprises video signal collective method, JPEG still image compression algorithm and asynchronous SOCKET network transfer method.

Beneficial effect of the present invention mainly shows: the remote collection of 1, realizing big data quantity in the current environment of narrowband network; 2, the video effect real-time is good; 3, low to network bandwidth requirement; The region characteristic that 4, can adapt to small hydropower station.

(4) description of drawings

Fig. 1 is the flow chart of the video frequency monitoring method of small hydropower station telemechanical system in narrowband network.

Fig. 2 is the structure chart of the video monitoring system of small hydropower station telemechanical system in narrowband network.

(5) embodiment

Below in conjunction with accompanying drawing the present invention is further described.

With reference to Fig. 1, Fig. 2, a kind of video frequency monitoring method of small hydropower station telemechanical system in narrowband network, described method mainly may further comprise the steps:

(1), the collection of video data stream: what gamma camera was input to video frequency collection card is the AV vision signal of standard, and its peak-peak value is 1.0V.Video frequency collection card adopts the mode of over-sampling that vision signal is sampled, to guarantee the correctness of signal sampling.Simultaneously, according to standard H.264 encoding video signal and compression that sampling obtains finally are converted into digital video frequency flow and by pci bus video data stream are sent to the video acquisition module of moving in the host computer and handle.For the real-time that guarantees that video data stream is handled, prevent to cause the generation of frame losing phenomenon owing to the time-delay of application program, the host computer application program is to be undertaken by the form of readjustment to the collection of the video data stream on the video frequency collection card, promptly when video frequency collection card collection and coding, compress what a complete frame of video after, just come receiving video data stream by the function in the form caller of call back function immediately.From video flowing, extract the raster pattern C of bmp form, and the data volume of bmp picture is still bigger comparatively speaking, (through test, for the bmp picture of a 384*288 who grasps, its data volume is about 300K).

(2), narrowband dialing is connected with network: the arrowband online adopts point-to-point Dial-up Network to be connected into Internet by modulator-demodulator (MODEM).The narrowband network of this programme carries out the PPP dial-up connection by the RAS AP services I of Windows system, and relies on the dynamic-dns name server to carry out the dynamic IP location.Start flow process: communication scheme enters holding state from starting state, waits for outside PSTN dialing jingle bell in holding state.The real-time ringing signal of holding state if receive ringing signal, is promptly represented the arrowband enabling signal, starts RAS dialing and PPP connected state and detects thread.RAS dialing thread is used to operate MODEM, and opens the Internet connection.The PPP connected state detects thread and monitors that narrowband network connects situation, if disconnect unusually, then jumps to starting state, opens again to connect.If long-range transmission ON-and OFF-command, then once monitoring end of expression just enters normal off-state, and process finishes.

(3), foundation is connected with the network of server: after the connection of client and server is set up, server verifies the legitimacy of client with regard to beginning, and the mode that server adopts username and password is verified the legitimacy of the client that is linked into server.Before the legitimate verification of client does not pass through, server will can not respond the request that any client sends.Simultaneously, because the linking number of the client that server is supported is limited, and the unusual end of connection that causes owing to reasons such as network, video controlled terminal abnormal ends often can not in time detect and still taking the Internet resources of server, the SOCKET connection that therefore need detect timely and clear up owing to take place to disconnect unusually.This method uses " Heart-beat " mode to detect client connection situation: server regularly sends a test data to client, if client receives this test data, then send it back a feedback, if server is not received feedback in a period of time after sending test massage, think that then this connection disconnects unusually.When server detect client connect disconnect unusually after, then clear up this connections, when new client connection access, reactivate this connection.

(4), the maintenance of figure frame queue: the video figure frame C that will at every turn extract by extraction time order be saved in the figure frame queue.The formation total length is L (Q), but the figure frame length of the current computing of formation is AL (Q), is limited to ML (Q) on the queue length.The figure frame queue can add current figure frame C, when L (Q)＞ML (C), and the figure frame of deletion formation stem.

(5), calculate region of variation rectangular matrix T _Min:

(5.1) traversing graph frame queue Q takes out vectorial H=((σ from formation _{I＜L (Q)}(Q)) ∩ (σ _{I＞AL (Q)}(Q _i))) ^T

(5.2) the difference degree vector Diff of each element among current figure frame C of calculating and the historigram frame vector H ^T, difference degree computing function is ${\mathrm{Diff}}_k=\underset{j=1}{\overset{\mathrm{width}\left(C\right)}{\mathrm{\Σ}}}\underset{i=1}{\overset{\mathrm{height}\left(C\right)}{\mathrm{\Σ}}}\mathrm{abs}(\mathrm{pix}(C,i,j)-\mathrm{pix}(H_k,i,j));$

(5.3) from vectorial Diff ^TIn find out minimum value Diff _Min=min (Diff ^T), Diff _MinSequence number be k;

(5.4) calculate region of variation rectangular matrix T _Min=σ _{Diff ≠ 0}(Diff _Min);

(6), compression variation zone raster pattern

(6.1) with region of variation rectangular matrix T _MinBe converted to raster pattern C ₁, and

$\left\{\begin{array}{c}\mathrm{width}\left(C_1\right)\←\mathrm{width}\left(T_{\min }\right)\\ \mathrm{height}\left(C_1\right)\←\mathrm{height}\left(T_{\min }\right)\end{array}\right.;$

(6.2) utilize jpeg image compression algorithm compression raster pattern C ₁, obtain compressed image J; Simultaneously, with the current raster pattern C adding figure frame queue tail end that collects.

(7), the asynchronous SOCKET transmission of region of variation compressed image

(7.1) TCP is connected between video controlled terminal and video server;

(7.2) compressed image J is stored in the data flow, and is divided into piece smaller or equal to 1024 byte-sized;

(7.3) by asynchronous SOCKET, with the video server that is transferred to of each data block order;

(7.4) video server connects each data block according to transmission sequence again after receiving all data blocks, is assembled into compressed image J;

(8), decompress(ion) region of variation raster pattern

(8.1) will utilize the image J after the jpeg image compression algorithm is compressed to be converted to raster pattern C ₂

(8.2) with raster pattern C ₂Be converted to region of variation rectangular matrix T _s, and $\left\{\begin{array}{c}\mathrm{width}\left(T_s\right)\←\mathrm{width}\left(C_2\right)\\ \mathrm{height}\left(T_s\right)\←\mathrm{height}\left(C_2\right)\end{array}\right.;$

(9), the current figure frame C ' of reduction

(9.1) traversing graph frame queue Q takes out the figure frame H of corresponding sequence number from formation _i

(9.2) with the region of variation matrix T _sRevise figure frame H _i, obtain current figure frame C ', promptly

$\left\{\begin{array}{c}{C^{,}}_{\mathrm{kj}}=\mathrm{pix}(T_s,k,j)+\mathrm{pix}(H_i,k,j)\\ k=1\·\·\·\mathrm{height}\left(H_i\right)\\ j=1\·\·\·\mathrm{width}\left(H_i\right)\end{array}\right.;$

(10), handle the cradle head control order;

(11), circular treatment video monitoring step, to step (1).

With reference to Fig. 1, the course of work of the video frequency monitoring method of small hydropower station telemechanical system in narrowband network is:

The first step: initialization video equipment and communication apparatus comprise camera, The Cloud Terrace, MODEM, ethernet nic and industrial computer.

Second step: open the RAS dialer map, obtain corresponding dial-up connection, detect the MODEM operating state, be in wait state and then start the PPP dialing by API.

The 3rd step: detect PSTN dial-up connection state, if connection failure then return step 2 reconnects.

The 4th step: open tcp protocol stack, obtain the network ip address of server, and connect authentication, host-host protocol is shaken hands, by the server security inspection.

The 5th step: start video frequency collection card by the video acquisition card driver.Video frequency collection card can be deposited the video information of collecting from camera in the core buffer of industrial computer by certain period.

The 6th step: in the industrial computer internal memory, distribute the memory headroom of believing to be used to set up empty figure frame queue.The maintenance of figure frame queue: the video figure frame C that will at every turn extract by extraction time order be saved in the figure frame queue.The formation total length is L (Q), but the figure frame length of the current computing of formation is AL (Q), is limited to ML (Q) on the queue length.The figure frame queue can add current figure frame C, when L (Q)＞ML (C), and the figure frame of deletion formation stem.

The 7th step: open asynchronous SOCKET with video server and be connected, set up the TCP network and connect.

The 8th the step: from video image buffering area reproduction video signal to internal memory.

The 9th step: in the middle of the streaming media buffer district, extract the static grating image C of a frame constantly.

The tenth step: if figure frame queue length be 0 then raster image C is carried out JPEG compression obtain J, and jumped directly to for 15 steps.If figure frame queue length is not 0 then continues following steps.

The 11 step: traversing graph frame queue Q, take out vectorial H=((σ from formation _{I＜L (Q)}(Q)) ∩ (σ _{I＞AL (Q)}(Q _i))) ^T, calculate the difference degree vector Diff of each element among current figure frame C and the historigram frame vector H ^T, difference degree computing function is

${\mathrm{Diff}}_k=\underset{j=1}{\overset{\mathrm{width}\left(C\right)}{\mathrm{\Σ}}}\underset{i=1}{\overset{\mathrm{height}\left(C\right)}{\mathrm{\Σ}}}\mathrm{abs}(\mathrm{pix}(C,i,j)-\mathrm{pix}(H_k,i,j)).$

The 12 step: from vectorial Diff ^TIn find out minimum value Diff _Min=min (Diff ^T), Diff _MinSequence number be k.

The 13 step: calculate region of variation rectangular matrix T _Min=σ _{Diff ≠ 0}(Diff _Min); With region of variation rectangular matrix T _MinBe converted to raster pattern C ₁, and $\left\{\begin{array}{c}\mathrm{width}\left(C_1\right)\←\mathrm{width}\left(T_{\min }\right)\\ \mathrm{height}\left(C_1\right)\←\mathrm{height}\left(T_{\min }\right)\end{array}\right..$

The 14 step: will utilize the image J after the jpeg image compression algorithm is compressed to be converted to raster pattern C ₂

The 15 step: with the current raster pattern C adding figure frame queue tail end that collects.

The 16 step: TCP is connected between video controlled terminal and video server, and J is stored in the data flow with compressed image, and is divided into the piece smaller or equal to 1024 byte-sized.By asynchronous SOCKET, with the video server that is transferred to of each data block order.Video server connects each data block according to transmission sequence after receiving all data blocks, be assembled into compressed image J.

The 17 step: search corresponding figure frame Hi.

The 18 step: utilize the image J after the jpeg image compression algorithm is compressed to be converted to raster pattern C ₂, with raster pattern C ₂Be converted to region of variation rectangular matrix T _s, and $\left\{\begin{array}{c}\mathrm{width}\left(T_s\right)\←\mathrm{width}\left(C_2\right)\\ \mathrm{height}\left(T_s\right)\←\mathrm{height}\left(C_2\right)\end{array}\right..$

The 19 step: traversing graph frame queue Q, take out the figure frame H of corresponding sequence number from formation _i, with the region of variation matrix T _sRevise figure frame H _i, obtain current figure frame C ', promptly $\left\{\begin{array}{c}{C^{,}}_{\mathrm{kj}}=\mathrm{pix}(T_s,k,j)+\mathrm{pix}(H_i,k,j)\\ k=1\·\·\·\mathrm{height}\left(H_i\right)\\ j=1\·\·\·\mathrm{width}\left(H_i\right)\end{array}\right.;$

The 20 step: handle the cradle head control order.

The 21 step: check and withdraw from signal, do not forward step 8 continuation monitoring to if withdraw from signal.

The 22 step: withdraw from the monitoring circulation.

With reference to Fig. 2, use the video monitoring system of the small hydropower station telemechanical system in narrowband network of this method realization, mainly comprise: video controlled terminal subsystem, video server subsystem.

Described video controlled terminal subsystem comprises:

(1) hardware device: comprise The Cloud Terrace, video camera, video frequency collection card, industrial computer etc.

(2) screen buffer acquisition module: the screen buffer acquisition module is to read relevant real time flow medium data the stream medium data internal memory that will gather from video frequency collection card to the module of formulating internal memory.

(3) figure frame cutting module: this module compares with the traversing graph frame queue and with current figure frame, calculates minimum region of variation rectangle.

(4) asynchronous SOCKET network transmission module: this module is used to finish the figure frame transmission work of network, adopts time-division multiplexing (TDM) in transmission, and promptly a plurality of surveillance equipments only transmit the image of an equipment simultaneously.

(5) JPEG still image compression module: this module is used for raster pattern is used JPEG still image compression algorithm boil down to jpeg image format, further dwindles data quantity transmitted.

(6) figure frame queue maintenance module: reduce the distribution and the release of Operation and Maintenance internal memory for the increase of figure frame queue.

(7) cradle head control signal processing module: handle the video control command and the operation of The Cloud Terrace.

(8) network error is handled and is recovered module: handle the improper mistake that often runs under the narrowband network.

Described video server subsystem comprises:

(1) hardware device: comprise ethernet device, industrial computer etc.

(2) the figure frame recovers module: this module searches historigram frame also restores current figure frame by the variation rectangular matrix that network receives.

(3) asynchronous SOCKET network receiver module: this module is used to finish the figure frame reception work of network,

Adopt time-division multiplexing (TDM) in transmission, promptly a plurality of surveillance equipments only transmit the image of an equipment simultaneously.

(4) still image modular converter: the minimum rectangle compressed image that receives is converted to raster image.

(5) figure frame queue maintenance module: reduce the distribution and the release of Operation and Maintenance internal memory for the increase of figure frame queue.

(6) cradle head control signal processing module: handle the video control command and the operation of The Cloud Terrace.

(7) network error is handled and is recovered module: handle the improper mistake that often runs under the narrowband network.

Claims (10)

1, a kind of video frequency monitoring method of small hydropower station telemechanical system in narrowband network, this video monitoring system comprises video monitoring main frame, video camera, The Cloud Terrace, video frequency collection card, network interface card and modulator-demodulator, this video frequency monitoring method may further comprise the steps:

(1), the collection of video data stream: start video camera, video frequency collection card is sampled to the vision signal of video camera by the mode of sampling, encoding video signal and compression to sampling obtains are converted into digital video frequency flow, extract raster pattern frame C from video flowing;

(2), narrowband dialing is connected with network: adopt point-to-point Dial-up Network to be connected into Internet by modulator-demodulator;

(3), foundation is connected with the network of server: after the connection of client and server was set up, server adopted the mode of username and password that the legitimacy of the client of access is verified;

(4), the maintenance of figure frame queue: the video figure frame C that will at every turn extract by extraction time order be saved in the figure frame queue, the formation total length is L (Q), but the figure frame length of the current computing of formation is AL (Q), is limited to ML (Q) on the queue length; The figure frame queue adds current figure frame C, when L (Q)＞ML (C), and the figure frame of deletion formation stem; It is characterized in that: described video frequency monitoring method is further comprising the steps of:

(5), calculate region of variation rectangular matrix T _Min: traversing graph frame queue Q, calculate the difference degree vector Diff of each element among current figure frame C and the historigram frame vector H ^T, calculate region of variation rectangular matrix T _Min

(6), compression variation zone raster pattern: with region of variation rectangular matrix T _MinBe converted to raster pattern C ₁, utilize jpeg image compression algorithm compression raster pattern C ₁, obtain compressed image J; Simultaneously, with the tail end of the current raster pattern C adding figure frame queue Q that collects;

(7), the asynchronous SOCKET transmission of region of variation compressed image: be connected between video controlled terminal and the video server, J is transferred to video server with compressed image;

(8), decompress(ion) region of variation raster pattern: will utilize the image J after the jpeg image compression algorithm is compressed to be converted to raster pattern C ₂, with raster pattern C ₂Be converted to region of variation rectangular matrix T _s

(9), the current figure frame C ' of reduction: traversing graph frame queue Q, the figure frame H of the corresponding sequence number of taking-up from formation _i, with the region of variation matrix T _sRevise figure frame H _i, obtain current figure frame C '.

2, the video frequency monitoring method of a kind of small hydropower station telemechanical system in narrowband network as claimed in claim 1 is characterized in that: described (5) may further comprise the steps:

(5.1), traversing graph frame queue Q, take out vectorial H=((σ _{I＜L (Q)}(Q)) ∩ (σ _{I＞AL (Q)}(Q _i))) ^T

(5.2), calculate the difference degree vector Diff of each element among current figure frame C and the historigram frame vector H ^T, difference degree computing function is: ${\mathrm{Diff}}_k=\underset{j=1}{\overset{\mathrm{width}\left(C\right)}{\mathrm{\Σ}}}\underset{i=1}{\overset{\mathrm{height}\left(C\right)}{\mathrm{\Σ}}}\mathrm{abs}(\mathrm{pix}(C,i,j)-\mathrm{pix}(H_k,i,j));$

(5.3), from vectorial Diff ^TIn find out minimum value Diff _Min=min (Diff ^T), Diff _MinSequence number be k;

(5.4), calculate region of variation rectangular matrix T _Min=σ _{Diff ≠ 0}(Diff _Min).

3, the video frequency monitoring method of a kind of small hydropower station telemechanical system in narrowband network as claimed in claim 2 is characterized in that: described (6) may further comprise the steps:

(6.1), with region of variation rectangular matrix T _MinBe converted to raster pattern C ₁, and

$\left\{\begin{array}{c}\mathrm{width}\left(C_1\right)\←\mathrm{width}\left(T_{\min }\right)\\ \mathrm{height}\left(C_1\right)\←\mathrm{height}\left(T_{\min }\right)\end{array}\right.;$

(6.2), utilize jpeg image compression algorithm compression raster pattern C ₁, obtain compressed image J; Simultaneously, with the tail end of the current raster pattern C adding figure frame queue Q that collects.

4, the video frequency monitoring method of a kind of small hydropower station telemechanical system in narrowband network as claimed in claim 3 is characterized in that: described (7) may further comprise the steps:

(7.1), TCP is connected between video controlled terminal and video server;

(7.2), compressed image J is stored in the data flow, and be divided into piece smaller or equal to 1024 byte-sized;

(7.3), by asynchronous SOCKET, with the video server that is transferred to of each data block order;

(7.4), video server after receiving all data blocks, connect each data block according to transmission sequence again, be assembled into compressed image J.

5, the video frequency monitoring method of a kind of small hydropower station telemechanical system in narrowband network as claimed in claim 4 is characterized in that: described (8) may further comprise the steps:

(8.1), will utilize the image J after the jpeg image compression algorithm is compressed to be converted to raster pattern C ₂

(8.2), with raster pattern C ₂Be converted to region of variation rectangular matrix T _s, and $\left\{\begin{array}{c}\mathrm{width}\left(T_s\right)\←\mathrm{width}\left(C_2\right)\\ \mathrm{height}\left(T_s\right)\←\mathrm{height}\left(C_2\right)\end{array}\right..$

6, the video frequency monitoring method of a kind of small hydropower station telemechanical system in narrowband network as claimed in claim 5 is characterized in that: described (9) may further comprise the steps:

(9.1), traversing graph frame queue Q, from formation, take out the figure frame H of corresponding sequence number _i

(9.2), with the region of variation matrix T _sRevise figure frame H _i, obtain current figure frame C ', promptly

$\left\{\begin{array}{c}{C\text{'}}_{\mathrm{kj}}=\mathrm{pix}(T_s,k,j)+\mathrm{pix}(H_i,k,j)\\ k=1\·\·\·\mathrm{height}\left(H_i\right)\\ j=1\·\·\·\mathrm{width}\left(H_i\right)\end{array}\right..$

7, the video frequency monitoring method of a kind of small hydropower station telemechanical system in narrowband network as claimed in claim 1, it is characterized in that: in described (1), when video frequency collection card collection and coding, compress what a complete frame of video after, come receiving video data stream by the function in the form caller of call back function immediately.

8, the video frequency monitoring method of a kind of small hydropower station telemechanical system in narrowband network as claimed in claim 1, it is characterized in that: in described (2), narrowband network carries out the PPP dial-up connection by the RAS AP services I of Windows system, and relies on the dynamic-dns name server to carry out the dynamic IP location.

9, the video frequency monitoring method of a kind of small hydropower station telemechanical system in narrowband network as claimed in claim 1, it is characterized in that: in described (3), server regularly sends a test data to client, if client receives this test data, then send it back a feedback, if server is not received feedback in a period of time after sending test massage, think that then this connection disconnects unusually.

10, the video frequency monitoring method of a kind of small hydropower station telemechanical system in narrowband network as claimed in claim 9 is characterized in that: after server detects client and connected disconnection unusually, then clear up this connection; When new client connects access, reactivate this connection.

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