Research On Pose Response Of Roadheader During Cutting Process And Swing Speed Control Of The Cutting Arm

Coal is the main energy source in China.With the increase of mining depth,all kinds of natural disasters in mining operation area become more and more serious.Therefore,the unmanned mining equipment has become an important development goal in the coal industry of China.In the fully mechanized excavation face,application of the boom-type roadheader has greatly improved the drivage efficiency of the roadway,but there are still many problems,which seriously restrict the development of intelligent unmanned fully mechanized drivage.Roboticized autonomous navigation and control of boom-type roadheader is the primary problem,and solution of its key basic scientific problems is the urgent affairs.In this paper,two key scientific problems are focused,which are pose response of boom-type roadheader during cutting process and swing speed control method of the cutting arm.Through dynamic modeling and analysis,the pose response regularities of the roadheader during cutting process were obtained.A kind of swing speed control method of the cutting arm was proposed and studied,which can automatically adjust the swing speed of the cutting arm according to the hardness change of coal and rock.Solution of the two scientific problems provides the theoretical basis and support for the realization of roboticized autonomous navigation and control of boom-type roadheader.(1)Based on the Lagrange equation,the dynamical coupling model of the pose of boom-type roadheader during cutting process was established.The pose change phenomenon of boom-type roadheader during cutting process and its influence factors were analyzed.The pose change parameters were determined,which are lateral displacement,backward displacement,floor-based displacement,pitch angle,roll angle and deviation angle,and the influence factors were determined,which are the cutting loads,swing angle of the cutting arm and dip angle of the coal seam.And a kind of discretized calcution method of the cutting loads was proposed.The second kind Lagrange equation was introduced and deformed,and the kinetic energy,potential energy and dissipation energy of the whole system of roadheader during cutting process were completely calculated.Aiming at the two operation conditions of horizontal cutting and vertical cutting,the differential equations of motion for the pose change of the roadheader were derived,and the dynamical coupling model of the pose of roadheader during cutting process was established,which can provide a complete theoretical model for the dynamic analysis of the roadheader.(2)The pose response regularities of boom-type roadheader during cutting process were obtained through analysis.Based on Simulink software,the dynamical coupling model of the pose of boom-type roadheader during cutting process was simulated and analyzed,and the pose response regularities of boom-type roadheader during cutting process in different operation conditions under the influence of multi-factors were obtained.During the horizontal cutting process,the lateral displacement can reach up to 6.5 cm,the backward displacement can reach up to 5.2 cm,the floor-based displacement can reach up to 11 cm,the pitch angle can reach up to 7.80,the roll angle can reach up to 2.1°,and the deviation angle can reach up to 7°.During the vertical cutting process,the lateral displacement can reach up to 6.2 cm,the backward displacement can reach up to 3.7 cm,the floor-based displacement can reach up to 13.3 cm,the pitch angle can reach up to 9.3°,the roll angle can reach up to 4.5°,and the deviation angle can reach up to 6.4°.Aiming at the special operation condition of steep coal seam,whose dip angle is 30°,the pose response regularities of roadheader during cutting process was analyzed.During the horizontal cutting process,the lateral displacement can reach up to 8.8 cm,the backward displacement can reach up to 4.5 cm,the floor-based displacement can reach up to 14.6 cm,the pitch angle can reach up to 9.1°,and the roll angle can reach up to 2.4°.During the vertical cutting process,the lateral displacement can reach up to 9 cm,the backward displacement can reach up to 4.1 cm,the floor-based displacement can reach up to 16.9 cm,the pitch angle can reach up to 8.8°,and the roll angle can reach up to 2.9°.In all kinds of operation conditions,the cutting loads has great influence on the pose change of roadheader,while the influence of swing angle of the cutting arm and dip angle of coal seam is relatively less.The dip angle of coal seam has no influence on the change of deviation angle,which is only influenced by the cutting loads and swing angle of the cutting arm.(3)Based on the Lagrange equation,the radial runout dynamical model of the cutting arm during cutting process of the roadheader was established,and the radial runout regularities of the cutting arm were obtained through analysis.The radial runout phenomenon of the cutting arm during cutting process of the roadheader and its influence factors were analyzed.Based on the deformed Lagrange equation,aiming at the horizontal and vertical radial runout phenomenon of the cutting arm,the corresponding differential equations of motion were derived,and the radial runout dynamical model of the cutting arm was established.Based on Simulink,the dynamical model was simulated and solved,and the radial runout regularities of the cutting arm were obtained through analysis.In the horizontal direction,the radial runout quantity of the cutting arm can reach up to 5.3°,and its minimum is 0.5°.In the vertical direction,the radial runout quantity of the cutting arm can reach up to 5.4°,and its minimum is 0.3°.The cutting loads has great influence on the radial runout of the cutting arm,while the influence of swing angle of the cutting arm is relatively less.Finally,the correctness of the radial runout regularities of the cutting arm during cutting process of the roadheader were verified by the actually measured data in the field of underground coal mine.(4)A kind of swing speed control method and strategy of the cutting arm was proposed,and the simulation study was accomplished.The swing speed control strategy of the cutting arm was established,and the constant power cutting will be realized through controlling the swing speed of the cutting arm.A kind of judgment method of the change of cutting loads based on multi-parameter criteria was proposed,in which the change of cutting loads can be accurately judged according to the change of the voltage and current of cutting motor,the pressure of driving cylinders of the cutting arm,and the vibration acceleration of the cutting arm.The BP neural network was utilized to ensure the constant output power of cutting motor,and the BP neural network was designed and optimized by genetic algorithm.Based on the actually measured data in the field of underground coal mine,the training samples were obtained.Based on Simulink,the simulation control system of swing speed of the cutting arm was established,and the control method was simulated and analyzed.The results show that this method can automatically adjust the swing speed of the cutting arm according to the hardness change of coal and rock,and ensure that the cutting motor can perform constant power cutting at its rated power.Moreover,the control method has high precision and quick response.