Study On Adaptive Control Of Shearer With Variable Speed Cutting

Drum shearer is the main equipment of mechanized coal mining, and it is an important technical equipment for the realization of intensive mining, which has been widely used in coal mining under different geological conditions. However, there are still many problems of current shearer: the intelligent level is low, and stand-alone automation control has not yet been achieved. Since only the hauling speed of current shearers is controlled without adjusting the drum rotation speed, the shearer can not keep the high cutting performance due to changes of cutting impedance, which leds to results such as low lump coal rate and heavy dust. This will reduce the forthputting and economic value of raw coal, and even generate health and safety hazards. Therefore, achieving shearer's adaptive control and improving cutting efficincy in the entire coal wall have been one of the research hotspots of the cutting equipments and technologies.Conection with the national key basic research and development program(973 Program) project——“Key basic research on unmanned mining equipment for deep and dangerous coal seam”(No: 2014CB046304). On the basis of existing research, the paper studies the adaptive control of shearer with variable speed cutting. Specially, the main contents of are as follows:(1) The structure, working mechanism and working characteristics of the existing electric traction drum shearer are expounded, and then the load and kinematics relation of the cutting part and the hauling part of the shearer are analyzed. Based on one 300 kW shearer, the simulation model including hauling part, cutting part and control systems is built using the Matlab/Simulink software, which could contribute to the following studies of the adaptive control of shearer with variable speed cutting.(2) The relationship between coal cutting impedance and cutting motor current is acquired from theoretical derivation and analysis of experiment and simulation data. The simulation data is decomposition and characteristic value is extracted with wavelet packet. And the coal cutting impedance ranges should be obtained with BP neural network pattern recognition.(3) The coal seam suitable for drum shearer mining is divided into different ranges by cutting impedance. And each range corresponds to the optimized hauling speed and drum rotation speed which are derivatived with PSO that aims to the comprehensive optimation of lump coal rate, energy consumption rate and production rate, and the constraint conditions are cutting motor power, hauling motor power and so on. The changes of coal cutting resistance are defined, and the speed control strategies of different conditions are analyzed and made. At last, an adaptive control method of shearer with variable speed cutting and the overall strategy are presented.(4) Finally, the speed control methods of the shearer cutting motor and hauling motor are analyzed and compared: the speed controller of traditional vector control variable frequency speed control system is improved with parameter adaptive fuzzy PI controller. The speed control signals are optimized, and results of different method are compared. The simulation of shearer's adaptive control with variable speed cutting under different conditions are also compared.