Research On Deviation Mechanism And Automatic Reconnection Control Of Coal Auger

The special principle of coal auger makes it the best choice of mining equipment for thin and extremely thin coal seams.However,the force of the drilling mechanism is very complex in the drilling process.With the increase of drilling depth,the drilling mechanism deviates from the original direction,which causes the phenomenon of sticking.The drilling deviation directly affects whether the limited thin coal seam resources can be fully exploited and utilized.In addition,because of the long time-consuming of the automatic reconnection of drill pipe,the working efficiency of coal auger is seriously restricted.To reduce the deviation in the drilling process and improve efficiency of automatic reconnection are the key problem to be solved.Based on this,this paper study the deflection mechanism,deflection characteristics,directional correction and automatic reconnection by using theoretical analysis,simulation and test research.To reveal the deviation mechanism of the coal auger,the sinusoidal buckling and spiral buckling instability model are established.The different buckling instability critical load and critical speed of the drilling mechanism under the factors such as the axial cutting resistance,centrifugal force,self weight and friction are obtained.Combined with the characteristics of coal seam geological structure,the interaction vector mathematical model of coal seam anisotropy and cutting mechanism is established.And the influence rules of coal seam dip angle,strike,azimuth and anisotropy on deflection are obtained.Based on the structure of the drilling mechanism,the deflection force equations under different BHA are established,and the deflection mechanism under the action of different axial cutting resistance,stabilizer outer diameter,the length of the first span of drill-pipe and line weight of drill-pipe are studied.The optimal arrangement of the drilling assembly is proposed to provide theoretical support for the research of the directional drilling of coal auger.To obtain the best working parameters of coal auger,based on the multi-body dynamics theory,the simulation and experimental research on the deflection vibration characteristics with different structures are carried out on the coal and rock cutting test-bed.The results show that the anti deflection ability,vibration characteristics and deflection force of the five bit mechanism are obviously better than that of the three bit mechanism.Under the complex load,the horizontal deflection and vibration of the drilling mechanism are greatly affected,and the vertical deviation is basically unchanged.The research results provide a reference for the selection of the best working parameters.To achieve the goal of directional drilling,a comprehensive directional deviation correction scheme with reasonable parameters,structural optimization and automatic deviation correction control is proposed.A new type of five bit structure is designed to increase the horizontal plane mining width of the drilling mechanism and improve the overall rigidity.The stabilizer is arranged which pointed out that the arrangement with the the spacing of five drill pipes is the best combination of parameters.This not only can effectively inhibit the deviation of coal auger and improve the anti deviation performance,but also can ensure the smooth ensure the smooth coal transportation.Based on the extended state observer,the backstepping sliding model position tracking control strategy is proposed.The parameter uncertainty and uncertainty nonlinearity of the system in the drilling process are estimated through the design of extended state observer.Based on the observer,the backstepping slide model controller is designed to track the position of the steering cylinder,which avoids the unmeasurable load in drilling process.The system chattering is effectively reduced,and the application feasibility of the directional control is guaranteed.To realize the automatic reconnection of drill-pipe,the test platform is established.The adaptive robust control strategy based on Lu Gre friction model is proposed.Based on genetic algorithm and system identification algorithm,the static and dynamic parameters of dynamic friction model are identified.The nonlinear observation of Lu Gre friction model is constructed to estimate the nonlinear friction state.The adaptive rate is designed to compensate the friction moment dynamically.The design of the robust feedback item can ensure the robust performance of the uncertain nonlinear system and realize the accurate angle signal tracking under various working conditions.The research results provide an effective control strategy for solving the problem of automatic reconnection.This dissertation has 85 figures,24 tables and 192 references.