Development Of Hydraulic Server Unit Based On 16-bit Microprocessor

The subject is not only 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),but also 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).It is proposed for lack of electro-hydraulic control system for hydraulic supports with great reliability and automation in fully-mechanized coal face.With the development of working face with high production and efficiency,it requires higher level of automation and intelligentialization for fully-mechanized mining equipment.As one of main mining equipment,the aumation degree of roof support has a great influence on the mining efficiency.Hydraulic server unit is an important part of the control system.It accomplishes the functions of remote control,online state monitoring,online update of support control unit and etc,reliazing the unattended fully-mechanized working face.In recent years,study on the Selectro-hydraulic control system has made great progress.However,most of the domestic electro-hydraulic control systems for roof supports are too unstable and low real time performance to be introduced to use in coal mine.Besides,due to long supply period,expensive price,hard maintance and bad communication compatibility of control system from abroad,working face with high production and efficiency is not popular in domestic coal mine.Therefore,it is of high practical meaning to develop reliable hydraulic server unit with our own intellectual property right.The overall scheme of server unit has been drawn in this paper;the hardware of server unit based on 16 bit Microprocessor MC9S12XDP512 has been designed.The software has been writeen in Code Warrior 5.1 IDE,which uses assembly language.Tests for the system have been done in the test platform of the laboratory.The results have shown that the control system was of high real time performance and reliability,could meet the practical mining requirement of coal mine.The main research contents are shown as follows:On the basis of surveys for current electro-hydraulic control system and mining technology used in domestic coal mine,the structure and function of hydraulic server unit was analyzed,the technical specification was designed and the overall scheme of the control systen was proposed.The overall structure of server unit's hardware was designed.MC9S12XDP512 was selected as control system's central processor unit,which is a kind of enhanced 16-bit microprocessor produced in Freescale Semiconductor.The basic running system was designed,which includes power supply circuit,system clock ciccuit,reset circuit,background debug interface circuit and PLL loop filter circuit.Then,RS-485 communication interface circuit was designed.The maxtrix keyboard,LCD display interface and running status indicators was also designed as human-machine interactive system.At last,external RAM interface was designed to store running parameters and program for system upgrade.After analyzing the function of the control system,software development platform and assembly language were choosed to written the software.The initiation of the system software was introduced in detail.The software of communicaton system and human-machine interactive system were designed using modulous method.Serial communication subroutine,switch of control mode subroutine,remote manual control subroutine,excution subroutine of remote jog control command from explosion-proof computer,excution subroutine of parameters modification command from explosion-proof computer,excution subroutine of telemetering parameters from explosion-proof computer,periodic telemetery function subroutine,centralized control start subroutine,calculation of the position and direction of sheaerer subroutine,evaluation of roof supports's running status subroutine,centralized control to excute sequence command and conveyor push subroutine were included in the designed communication system software.The Programs of human-machine interactive system were composed of keyboard service and LCD display subroutine,parameters modification subroutine,the selection of support's number subroutine,emergency stop function subroutine,communication errors display subroutine,encryption and passwords modification function subroutine.The program mentioned above was compiled and debugged.The results has shown that the software is of great performance in control logic and friendly to be transplanted,providing a prerequisite for well system running state.The tests for the hardware and function were carried out in test platform in laboratory.The test results have shown that the designed server unit was of great real-time performance,and was able to collect the status of supports quickly and excute control for supports exactly.It can meet the practical requirement of coal mine and lay a solid foundation for the promotion of the control system.