Study On Sliding Mode Active Disturbance Rejection Drilling Control Of Hydraulic Roofbolter

Coal is still a dominant energy in China,and one of the important factors to ensure the long-term stable development of national economy and energy transformation.In order to realize coal mining underground,rock or coal-rock mixture must be excavated on both sides of coal seam by tunneling equipment,and then the surrounding rock of the goaf must be supported by bolting equipment to form a channel(roadway)for the transportation of coal,equipment and workers,etc.Because the stability of the surrounding rock in a roadway is damaged after tunneling,effectively supporting the roadway becomes the most important and urgent issue.Hydraulic roofbolter,as the main mechanical equipment for supporting a roadway,complete the task of drilling and installing anchor/anchor on surrounding rocks by controlling its swing angle and displacement to accurate position,as well as updating propulsion and rotational speed to drill a hole.Unreasonable drilling control may reduce the support efficiency,even lead to support failure.Therefore,it is important to study the drilling control of hydraulic roofbolter,with the purpose of achieving effective support of a roadway.Based on this,taking the inherent dead-zone,time-varying parameters and disturbances of hydraulic roofbolter into account,a fuzzy logic-based dead-zone compensation method is introduced to build the dead-zone compensation model,and then the following four parts of control works are put forward.Firstly,an adaptive sliding mode swing-angle tracking control method based on an improved nonlinear extended state observer is proposed for the rotation system of drill arm of a hydraulic roofbolter.An improved nonlinear extended state observer is designed to enhance the anti-disturbance capability of the system.In order to further improve the control accuracy and simplify the design,a new sliding mode surface based on an index function and dynamic surface method is given.Then,a new sliding mode reaching law is proposed,with the purpose of improving response speed and eliminating chatting of the sliding mode.Based on this,an estimation error adaptive law and a parameter adaptive law are designed to compensate the disturbance estimation error and suppress the negative effects of time-varying parameters.The effectiveness of the proposed control method is verified by comparing it with eight related control methods.Secondly,a global sliding mode finite-time displacement tracking control method based on a reduced-order proportional-differential extended state observer is presented for the displacement system of drill arm.A new reduced-order proportional-differential extended state observer based on tracking error is designed to estimate the disturbance more accurately,which has lower dimensionality and fewer gain parameters than the conventional one.Following that,a sliding mode unit consisting of a global integral sliding mode surface and a global sliding mode control law is constructed to improve the dynamic and steady-state control performance of the system in terms of the output of extended state observer,a performance function and an index function.The effectiveness of the proposed control method is verified by comparing it with ten classical control methods.Thirdly,an integral sliding mode propulsion tracking control method based on an integrated extended state observer is proposed for the propulsion system of a hydraulic roofbolter.The control method consists of four parts: transition process,observer,sliding mode unit and parameter adaptive law.The transition process converts the step reference propulsion into a continuous tracking signal,with the purpose of improving the response speed and avoiding overshoot.A self-switching integrated extended state observer is designed to effectively estimate the dynamic disturbance.In the sliding mode unit,a novel integrated sliding mode surface is designed to suppress the negative effects of disturbance estimation error and avoid high-frequency switching of the controller.A sliding mode reaching law based on a saturation function with variable boundary layer thickness is developed to enhance the robustness,speed up the convergence,and eliminate chattering.Finally,an adaptive sliding-mode control law is presented to provide an effective and continuous control signal.The effectiveness of the proposed control method is verified by comparing it with nine classical control methods.Finally,a global integral sliding mode rotary tracking control method based on an improved nonlinear extended state observer is designed for the rotation system of a hydraulic roofbolter,which mainly contains an observer,a sliding mode unit and an adaptive law.Based on the measurable state and hyperbolic tangent function,an improved nonlinear extended state observer is constructed to efficiently estimate the disturbance.A global integral sliding mode surface is developed by integrating an index function and dynamic surface method.A new global sliding mode control law is then designed to enhance the robustness and tracking accuracy.Based on projection function,control signal,and sliding mode surface,an uncertain gain adaptive law is presented to improve the control performance.The rationality of the proposed method is verified by comparing it with fourteen classical control methods.The above four parts of researches enriched the control theory and method of existing electro-hydraulic servo system,and provided effective technical assurance for supporting a roadway in a coal mine,which has important significance on theory and engineering.