| In the excavation process of a roadway,accurate and effective anchor or anchor-cable support is a key issue to ensure the safety and reliability of a coal mine,which directly influences the production efficiency of a coal enterprises and the safety of workers.The effectiveness of anchor or anchor-cable support depends on designing the overall structure of the anchor support network for a roadway at the beginning,as well as their precise positioning and the drilling control by the anchor-hole drill.In addition,the rapidity and accuracy of the anchor-hole drill moving to the designed position guarantees stress distribution of the surrounding rock and effective anchor support network of a roadway.When installing anchor or anchor cable in a roadway,the position of hydraulic anchor-hole drilling arm is manually controlled by workers,and a low accurate position generally results in the equipment failure,even the collapse of the roadway.To improve the accuracy of positioning the drilling arm,the angle controllers of the hydraulic anchor-hole drilling arm driven by a valve or a variable-frequency pump under the complex environment and the special working conditions were studied based on the existing modeling and hydraulic control technology.The main contents including the following three parts:(1)Aiming at the electro-hydraulic system of anchor-hole drilling arm driven by a valve,an adaptive sliding-mode control method based on Extended Kalman Filter(EKF)is proposed to overcome the influences from electro-hydraulic servo system,such as valve dead-zone nonlinearity,parameter uncertainty and unknown load disturbances and precisely tracking of the setting position.By introducing a smooth dead-zone inverse model,a dead-zone pre-compensator is designed to eliminate the dead-zone effect.The control law and the adaptive law based on the sliding-mode control strategy are designed to estimate the unknown dead-zone parameters and load disturbances.In addition,the EKF is employed to estimate the noise of the system and predict the position of the arm with the purpose of reducing the sliding-mode chattering.The joint simulation results of AMESim and MATLAB show that the designed controller can effectively compensate the dead-zone and eliminates the influence of load disturbance.Moreover,the system can accurately track the given position of the rotation angle of an anchor-hole drilling arm and verify the effectiveness of the proposed control strategy.(2)To meet the control requirements of the rotation angle for an anchor-hole drilling arm,a novel type rotary system of anchor-hole drilling arm driven by a variable-frequency pump is constructed and the corresponding model is built by novel.After further analyzing the system characteristics,a fuzzy PID controller for the rotation angle of hydraulic anchor-hole drilling arm driven by a variable-frequency pump is designed.The simulation results based on the MATLAB/Simulink show that the proposed control method has the batter position precise thus the rotation system driven by a variable-frequency pump.Moreover,the correctness and rationality of the model is verified for anchor-hole drilling arm driven by a variable-frequency pump.(3)Based on the above mentioned studies,an adaptive sliding-mode controller with dynamic switching function is presented,with the purpose of automatically controlling the rotation angle of hydraulic anchor-hole drilling arm driven by a variable-frequency pump.In the proposed controller,the adaptive law and dynamic sliding-mode are designed to restrain the internal and external disturbances,so as to eliminate the chattering and reduce the influence of the perturbation on the control system.The joint simulation results of AMESim and MATLAB show that the proposed controller can rapidly adjust the rotation angle of the drilling arm without overshooting and steady-state error,and effectively suppress the adverse effect of uncertainties on the control system.Compared with the proposed Fuzzy PID controller,the controller is more robust,and provides a stable supporting for a roadway,which provides a foundation for realizing high-precision positioning and installation of the anchor or anchor-cable. |
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