Method for implementing a centralized control platform of hydraulic support on fully mechanized mining working face in underground coal mines

A method for implementing a centralized control platform of a hydraulic support on a fully mechanized mining working face in underground coal mines, involving 30 hydraulic supports for completing a centralized control function once, including one coal mining machine in-place hydraulic support, fourteen coal mining machine front hydraulic supports and fifteen coal mining machine rear hydraulic supports;

• wherein the centralized control platform is connected to an electro-hydraulic control system, a TCP/IP MODBUS protocol is functioned as a communication protocol between the centralized control platform and the electro-hydraulic control system, the centralized control platform acts as a client, and the electro-hydraulic control system acts as a server end;
• an infrared transmission apparatus is mounted on a coal mining machine, a receiving apparatus is embedded into a holder controller of the electro-hydraulic control system, the holder controller receives infrared information from the infrared transmission apparatus and transmits the infrared information to an explosion-proof computer of the electro-hydraulic control system;
• the electro-hydraulic control system includes a holder control system, an end centralized control system and a crossheading monitoring system, the centralized control platform transmits a position of the coal mining machine to the explosion-proof computer of the electro-hydraulic control system in real time;
• the method comprising:
• (1) firstly transmitting, by the centralized control platform, a command of startup to the electro-hydraulic control system, and after obtaining a response that the electro-hydraulic control system has been prepared, transmitting, by the centralized control platform, a position signal of the coal mining machine and a process stage signal to the electro-hydraulic control system and starting the coal mining machine at the same time;
• (2) sending out a control command, by the electro-hydraulic control system, based on the position signal of the coal mining machine and a position detection signal of an encoder of the coal mining machine, such that a related hydraulic support automatically tracks the coal mining machine;
• (3) comparing, by the explosion-proof computer of the electro-hydraulic control system, information of two detection positions of the coal mining machine, transmitting normal information by the explosion-proof computer and continuing to implement next control by the centralized control platform if the two detection positions are the same;
• transmitting an alarm information by the explosion-proof computer such that the electro-hydraulic control system stops giving the control command if the two detection positions are different;
• wherein, the information of the two detection positions of the coal mining machine refers to the position signal of the coal mining machine transmitted from the centralized control platform and the position signal of the coal mining machine transmitted from the infrared transmission apparatus;
• (4) transmitting, by the centralized control platform, a number of current process stage and the position detection signal of the encoder of the coal mining machine to the electro-hydraulic control system every 0.5 s after the coal mining machine is started normally;
• providing, by the electro-hydraulic control system, information including front pillar pressure, rear pillar pressure, displacement stroke and a first state variable of the coal mining machine in-place hydraulic support, the coal mining machine front hydraulic supports and the coal mining machine rear hydraulic supports as a response after receiving the position detection signal of the encoder of the coal mining machine from the centralized control platform, wherein the first state variable includes whether the hydraulic support is normal or not, whether the holder controller is normal or not, whether an end controller is normal or not and whether communication is normal or not, so that the centralized control platform makes judgment whether centralized control can be continued or not;
• (5) judging, by the electro-hydraulic control system at anytime, whether physical variables related to an operation reach limit parameters, whether a displacement stroke is still not in place after a given operation limit time has passed, whether control information and return information form a closed loop or not;
• and whether communication is smooth or not when the electro-hydraulic control system controls an operation of the hydraulic support based on the number of current process stage and the position signal of the coal mining machine that are transmitted by the centralized control platform;
• (6) transmitting, by the centralized control platform, a write request of the number of process stage and the position of the coal mining machine to the electro-hydraulic control system, and transmitting a read request for collecting signals of the electro-hydraulic control system in real time at the same time, judging the type of a request by the explosion-proof computer of the electro-hydraulic control system after obtaining a request from the centralized control platform;
• (7) transmitting data in the read request in a form of a TCP/IP MODBUS protocol to the centralized control platform by the explosion-proof computer after the electro-hydraulic control system has received the read request from the centralized control platform;
• wherein, firstly transmitting first five numbers that are received;
• and secondly transmitting b×2+3 numbers, wherein, b is a number required by the client;
• and thirdly transmitting a 7th and an 8th numbers (i.e., device address and function code) that are received;
• and fourthly transmitting b×2 numbers;
• and fifthly transmitting a head address where the data is saved;
• and next transmitting data volume in sequence, and finally transmitting a check code;
• (8) performing analysis and judgment by the centralized control platform after receiving the data transmitted from the step (7), and stopping operation of the coal mining machine timely when there is a failure and giving an alarm at the same time.