| Coal resources are indispensable raw materials for basic industrial production.Rational development and use of coal is an important issue that affects the sustainable development of today’s society.Shallow coal resources have become increasingly exhausted after years of exploitation in China at present.With the increasing depth of mining,the difficulty of mining has also gradually increased.The vertical shaft drill plays a crucial role in drilling and blasting of rock in deep coal mining as key equipment for the development of deep shaft construction in coal.The vertical shaft drill used in engineering applications currently is mainly divided into pneumatic vertical shaft drill and hydraulic vertical shaft drill.Compared to pneumatic vertical shaft drill with low efficiency,slow motion,and high noise in hard rock drilling,hydraulic vertical shaft drill is continuous development in vertical shaft construction.It has become the research focus of domestic and foreign experts and scholars gradually.Recently,a new type of full-hydraulic four-armed vertical shaft drill was developed at the School of Mechatronic Engineering of China University of Mining and Technology.Its structure consists of hydraulic system,rock drilling system,ventilation and water circulation system and boom system.The hydraulic system provides power for the entire equipment.The rock drilling system completes the drill rod propulsion,extraction,rotation and impact movement.The ventilation and water circulation system has an effect to ventilate and clean the borehole during drilling process.The coordinated movement of the mechanical structure in boom system completes the adjustment of the position and posture of the drill rod.The boom system of hydraulic vertical shaft drill is characterized by the light weight of the slender mechanical structure in series,unlike other boom system in engineering machinery,the poor rigidity of the structure caused each arm in the actual movement of the elastic deformation and vibration is very obvious.The small changes in the displacement of the drive cylinders of each arm will cause a large offset in the end tip position and posture of the boom system through the amplification of the mechanical structure of the boom system.As a result,the drill rod position and posture is not easily controlled accurately.Although the new hydraulic vertical shaft drill has been innovative in structure design and transmission mode which has achieved good results,it has retained the traditional manual open-loop control method in the control mode.Due to the poor working conditions of the hydraulic vertical shaft drill and the existence of certain safety hazards,the existing manual open-loop control method cannot satisfy the construction requirements due to their low control accuracy,low efficiency.Therefore,aiming at the existing problems in the existing control methods of hydraulic vertical shaft drills,this paper takes a new hydraulic four-armed vertical shaft drill developed as the model by the School of Mechatronic Engineering of China University of Mining and Technology in order to improve the control performance.Realizing the electrohydraulic automatic control in boom system of hydraulic vertical shaft drill is the main research content.Designing an electrohydraulic control system that can automatic control the movement in boom system of hydraulic vertical shaft drill.Through the design of prototype of boom system according to the new type of full-hydraulic four-armed vertical shaft drill and design of an electro-hydraulic automatic control system for the boom system and experiments,the feasibility of the automatic electro-hydraulic control system was demonstrated.The specific research content of this paper is as follows.According to the working principle,overall mechanical structure and key technical parameters of the new type of full-hydraulic four-armed vertical shaft drill developed by the School of Mechatronic Engineering of China University of Mining and Technology,Designed for automatic control of hydraulic vertical shaft drill electrohydraulic control system.The new type of full-hydraulic four-armed vertical shaft drill used to model its experimental mechanical structure.Accordingly,design of electrohydraulic systems and measurement and control systems that meet its working requirements.In the design of the electrohydraulic system,the traditional load-sensing system dynamic response and power matching efficiency are improved.Under the electrohydraulic proportional servo control,the hydraulic system control accuracy and reliability are improved.The positive kinematics model of boom system of hydraulic vertical shaft drill was established by DH method,the inverse kinematics model was established by geometric method.And the function relationship between the joint space variables and the driving cylinder hydraulic variables was established.The correctness of kinematics modeling was verified by MATLAB Robotics Toolbox.Through rigid-body dynamics modeling and virtual prototyping modeling,the joint torque curve of the boom system is obtained.The error sources of the theoretical calculation and the virtual prototype simulation results are analyzed,and a rigid-flexible coupling model is more consistent with the actual movement of the umbrella drilling boom system of hydraulic vertical shaft drill is established.It is concluded that there are different degrees of elastic deformation through simulation analysis in the movement of the main boom and drill arm,and the deformation of the drill arm is greater than the deformation of the main boom.The vibration during the movement boom system is relatively small,and there is a large vibration in the start-stop process.The point velocity oscillation at the end tip of the drill arm is more obvious.Introducing random the actual hydraulic cylinder running speed curve into the rigid-flexible coupling model.The simulation results show that the speed planning can achieve the stable position and posture adjustment of the end of the drill arm of the boom system and reduce the shake of the boom system.In order to quickly complete the position and posture control of the end tip of the drill arm of boom system of hydraulic vertical shaft drill,the system jitter is suppressed to improve the motion stability and the control accuracy position and posture of the drill arm,and the hydraulic cylinder speed trajectory planning is performed to reduce the movement jitter of the boom system.The trajectory tracking of the boom system motion is controlled by PID and fuzzy PID algorithm,and the effects of two control methods in simulation analysis and experimental research are compared.From the fluctuations of the operating speeds of the main boom hydraulic cylinder and the slant cylinder in the PID experiment,the impact of the two cylinders is very large,which also shows that there is obvious elastic deformation and boom vibration during the movement of the boom system of hydraulic vertical shaft drill.The fuzzy PID overall control effect is good,although the hydraulic cylinder speed also has certain fluctuations,the fluctuation range is not large,and the time is also significantly reduced.Through parameter tuning,the fast and accurate control of the end tip position and posture of the drill arm within the range of 1 mm/s of the steady velocity error of the hydraulic cylinder under fuzzy PID correction is achieved,and the position and posture adjustment time of the drill rod are greatly reduced.Finally,the variable pose compensation is used to reduce the repeat position and posture error and absolute position and posture error at end tip of the drill arm,and the variable compensation method is used to control the position deviation between the end tip of the drill arm and the reference hole within 30 mm,and the angle deviation is within 0.5° to ensure 40 mm diameter drill rod of the boom system of hydraulic vertical shaft drill can pass through a preset 100 mm diameter hole.This paper presents the design of an electrohydraulic system for automatic control of hydraulic vertical shaft drill fisrt time.The load-sensing system using electrohydraulic proportional servo technology is applied to the motion control of the boom system of hydraulic vertical shaft drill to improve the control accuracy and reliability of the hydraulic system.The dynamic response and power matching efficiency of the load-sensing system enable energy saving,high precision in end tip of the drill arm control compared to traditional method.Through system design,theoretical analysis and simulation verification,the motion control problem of boom system of hydraulic vertical shaft drill was researched.The kinematics,rigid body dynamics and rigid-flexible coupling model of boom system of hydraulic vertical shaft drill were obtained.The correctness of modeling was proved by simulation research.It is suitable for simulation and experimental research of trajectory planning methods and control strategies for the motion of boom system of hydraulic vertical shaft drill,achieving effective control of the movement of boom system of hydraulic vertical shaft drill,greatly reducing the adjustment time of the position and posture of the drill rod,and improving the position posture accuracy.This paper aims at realizing the automatic control of the boom system of hydraulic vertical shaft drill,based on the actual object to carry out practical research,and the research results can also be applied to the motion control problems of the boom system of similar engineering machinery. |
PDF Full Text Request