Development Of The Electro-hydraulic Terminal Controller For Hydraulic Support Based On MC9S12XDP512

The subject is not only an important part of national and international scientific and technological cooperation in special projects “Development on the Control System of Electronic-Hydraulic Used in Hydraulic Support Unattended Fully Mechanized Coal Face”(NO.:2013DFA70750), but also an important part of the science major project of shanxi province “Research on Technical Equipment of Fully-automatic Domestic Unattended Fully Mechanized Coal Face”(NO.:20111101024). The research topic is to develop a hydraulic support centralized control system that is safe, reliable, high automated and easy to operate base on terminal controller. The control system has three layer networks, which comprised of explosion protected computers, terminal controller and support controller. The terminal controller was designed based on MC9S12XDP512 microcontroller. The control system could realize automatic control of hydraulic support in the fully mechanized working face, monitor the state of support in real-time, change the system parameter on-line, update the system program on-line, backup the centralized control system. The main research contents of this paper are shown as follows:At first, refer to domestic and foreign literature and field trip in fully mechanized coalface, three layer network structure of the control system were determined besed on the current study status and actual situation of coal industry in our country, which comprised of explosion protected computers, terminal controller and support controller. And the functional requirements and performance indicators were put forward.The communication system of terminal controller was designd based on RS485/Modbus bus. There are three modes to control the hydraulic support, which include the local control mode and remote control mode and centralized control mode. To improve the control system’s ability to adapt of the coal mine complex environment, system parameter modification scheme is designed. It is very complex and inconvenience to update the application software of hydraulic support control system In order to update the application software of hydraulic support control system, a scheme of online upgrade based on IAP is designed, the XRAM store link and data validation link are combined to improve the reliability of online upgrade. The hot backup solution of centralized control system based on terminal controller is designed, which could switch the mode to ensure the continuity of production of fully mechanized working face in case of the main terminal controller failure or the communication cable fault.According to performance requirements of the terminal controller and special environmental at coal mine, the hardware circuit of terminal controller was designed based on MC9S12XDP512, including the minimum system circuit, matrix keyboard circuit, LCD display circuit, RS485 communication circuit, sound-light alarm circuit and XRAM memory circuit. According to the circuit schematic diagram, the PCB circuit board is designed. After completed the prototype, the hardware was tested. To improve the stability of the hardware, heat ageing test was used to eliminate some teething problems, such as bad welding, electronic components parameters not match, temperature drift. And then, the EMC test was done to the whole machine. The result shows that the terminal controller had a certain resistance to electromagnetic interference.The software design of the terminal controller was based on CodeWarrior ide software development platform. According to the characteristics of system function, software architecture is designed based on break mode. After configured the bus clock, operation monitoring and interrupt resources, developed the program with modular design concept, including communication system program, three kinds of control mode of centralized control program, the system parameter modification program, online upgrade program, hot backup program and human-computer interaction program.The experiment platform of hydraulic support control system was built in the laboratory. Explosion protected computer, terminal controller and support controller were taken to laboratory simulation debug and system joint debug. After tested, the result shows that the terminal controller had a good stability and could meet the design requirements of each function and was enough to be used in the hydraulic support control system.