| As a kind of equipment widely used in construction of railway,highway,underground buildings,mines,water conservancy,hydropower tunnels or roadways,grouting machine has broad market prospects in national economic construction.At present,the emphasis of research on roadway support technology is mechanization and intellectualization,but most coal mines adopt manual shotcreting or manual shotcreting manipulator in the process of roadway support.The impact of the manipulator in the working process is tremendous,which is not conducive to the quality of shotcreting and the life of the manipulator.Although some achievements have been made in the research of shotcreting support technology,it has not impacted the joints of the shotcreting manipulator Automatic grouting control forms a systematic solution.Based on this,this paper studies the optimal trajectory planning and automatic control of shotcreting for manipulator motion.Based on the optimum grouting technology of the shotcrete manipulator,the structure design of the shotcrete manipulator is carried out,and the static and modal analysis of the manipulator is carried out by ANSYS Workbench to verify the rationality of the designed structure.The standard D-H method is used to establish the linkage coordinate system and analyze the forward and inverse kinematics.The relationship between the position and posture of the end-effector and the joint variables of the manipulator is obtained,which provides a theoretical basis for the subsequent trajectory planning and automatic control of the manipulator.Based on the optimal shotcrete path of the shotcrete manipulator,the linear interpolation method of high order polynomial transition is used to plan the optimal trajectory of horizontal shotcrete trajectory and the trajectory planning method of quintic B-spline is used to plan the optimal trajectory of vertical shotcrete trajectory.The trajectory function expression of the planned trajectory is obtained through theoretical analysis.The displacement and velocity of the manipulator are obtained by using MATLAB.The simulation results show that the displacement,velocity,acceleration and pulsation of the grouting manipulator are continuous after trajectory planning,which proves the rationality and effectiveness of the trajectory planning method.Based on the optimal trajectory of the manipulator after trajectory planning,the electro-hydraulic proportional position control system of the manipulator is designed.The mathematical models of the valve-controlled asymmetric hydraulic cylinder,proportional directional valve,proportional amplifier and displacement sensor are established.The transfer function of the system is obtained and the frequency spectrum is analyzed.The response time of the system is 5.5s.Then the system is corrected by adding a PID controller.The PID parameters are adjusted by trial and error method,and the system response time is 0.18 s after correction.The trajectory simulation model of the manipulator is established by using MATLAB/Simulink.The maximum error of the planned trajectory is 10 mm for horizontal trajectory and 2.1 mm for vertical trajectory.It can ensure the accurate realization of the optimal trajectory of the shotcrete manipulator and verify the rationality of the planned trajectory.Based on the grouting technology of the shotcrete manipulator,the PLC control system of the shotcrete manipulator is designed.The automatic control experiment of the shotcrete manipulator is carried out by taking the inverse kinematics solution of the manipulator as the input of the system.The accuracy of the inverse kinematics solution is verified by the grouting trajectory of the manipulator,and the change of the manipulator joint obtained by the sensor is compared with the inverse kinematics solution.The maximum errors of each joint are 3.4 degree,5.8 degree,0.3 degree,0.4 degree,0 mm and 0.2 degree respectively,which verifies the rationality and stability of the designed PLC control system. |
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