Research On Trajectory Tracking And Its Control Strategies Of Drum Shearer

All the time, underground mining is a high-risk engineering which requires high labor intensity. Therefore, scientists and engineers are always looking for perfect mining processes that are low-risk and productive. Mechanization and automation, off course, are effective approaches to improve production and decrease the danger from accidents. In coal mining industry, mechanization is widely applied in the world since in the middle of last century. Automation is also realized and applied in some good conditional faces of many developed nations, such as German, U.S., and England. In our country, underground mining automation is still on the stage of research and development, and there is larger distance between major coal producer and us. Short of key techniques, such as coal-rock recognition and face automatic alignment is the main reason of distance. Coal-rock interface identification problem will be the focus of this thesis, and indirection methods will be proposed to solve this problem, which can contribute to the automation of coal digging.In this dissertation, an automatically vertical steering system based on trajectory tracking is designed, firstly. This system is easily realized based on the commissioned sheared rather than requirement of high property controllers. Simulation and analysis is done to evaluate the property of the system. Besides, ground and underground rigs are designed to verify the correction of the simulation and design. On the other hand, in order to avoid the shortcoming of the design above, for example, low precision and action frequently, a vertical steering system which owns higher precision and reliability is designed. Control strategies are researched through simulation in order to improve the precision of the system. Each chapter of this dissertation is introduced as follows:In chapter1, coal mining craft which is suitable for automatically vertical steering system based on trajectory tracking is introduced. Variable methods of direction and indirection coal-rock interface recognition are summarized. Besides, their current situation and past development are introduced. Finally, the significance and main research subjects of this paper are presented.In chapter2, basic theory of tracking system is introduced, which focus on how to choose the sample period and feed way. Besides, two mathematical models designed below, including lever transmission construction and hydraulic system, are built, which is the foundation for the later simulation and analysis.In chapter3, detail design, system simulation and experimental research are introduced. Simulation and test results show that shearer automation based on PLC control platform are feasible, but there are obvious defects, such as low precision and high frequency drum adjustment. According to these problems, several control solutions are proposed.In chapter4, a tracking system with high precision and high reliability property for drum height automatic adjustment is designed. Details design of the coal-rock identification and trajectory tracking module is introduced through the comparison of different schemes. The advantages and characteristics of the load sensing hydraulic system applied in this scheme are analyzed. Finally, the feasibility of the system is verified by field tests, and the optimization scheme of hydraulic system and control system are put forward.In chapter5, co-simulation model of automatic height adjustment system is built in AMESim and MATLAB. PID control algorithm, PID control strategy based on speed compensation and fuzzy control strategy are put forwards and compared. Simulation research on these control strategy is done to choose the better one.In chapter6, Conclusions in this thesis are summarized and future research proposals are suggested.