Dynamic Modeling And Control Of Flexible Guided Lifting System In Shaft Construction

Shaft construction lifting system is a necessary part of drilling vertical shaft.There are strongly coupled vibration and deformation of the flexible rope in shaft construction lifting system due to the harsher environment of vertical shaft and the flexible property of the rope.Strongly coupled vibration will influence the internal steel wire,excessive vibration resulting in serious wear,premature fatigue failure and crack growth which cannot be ignored.The winding differences between all the winch drums will lead to an inclination of the suspension platform during the lifting process.It will frequently scrape the shaft sidewall and even happen major accidents such as stuck in the shaft.Therefore,vibration and control of the rope and leveling of suspension platform have great significance on shaft construction lifting system.The thesis is focused on dynamic modelling and control of the flexible guided lifting and suspension system for shaft construction.Combining with theoretical modeling,numerical simulation and experimental verification,it thoroughly investigates the dynamic behavior of the flexible guided lifting system.The aim of the thesis is to establish a physical model,derive governing equation of the system and give numerical solution method,which can accurately reflect dynamic responses of the flexible guided lifting and suspension system for shaft construction.An accurate physical model provides important information for understanding relationship of the boundary disturbance,control input,system vibration and suspension platform posture.Different adaptive boundary controllers are proposed to reduce system vibration and leveling the suspension platform in different working conditions,which provides theoretical and technical support for the efficient and safe operation for shaft construction lifting system.Firstly,according to the structure and working principle of the shaft construction lifting system,partial differential-ordinary differential model is established to reflect transversal and longitudinal coupled vibration of the system.Combining with the system natural frequency and the generalized ? algorithm,the dynamics response of the theoretical model is analyzed and verified by the ADAMS simulation model and the flexible guided lifting experimental system,which laid the foundation for the research on the control method of the flexible guided lifting system and suspension platform in construction shaft in the subsequent parts.Secondly,a full model of flexible guided lifting bucket system is established to reflect the impact of the free hanging bucket swing on the system.This part analyzes the fault type of rope guide and the swing behavior of the bucket,summarizes the response law of the rope guided fault to the system dynamics and proposes the critical value of the minimum running velocity of the lifting rope.Combining with finite dimensional backstepping method,Lyapunov theory and neural network,an adaptive backstepping controller with neural network is desiged at the carriage to suppress the vibration and stabilize the system state in the small neighborhood of the equilibrium position,where the model parameter uncertainties,external unknown disturbances,and non-smooth nonlinear input hysteresis are considered into the controller.The convergence and stability of the closed-loop system with time-varying length are verified by simulation.Thirdly,the dynamics model and control of the free suspension system are studied when the restraint between the suspension platform and the shaft sidewall is released.Based on the second chapter,a transversal coupled model between the flexible guided lifting system and the suspension platform is established.For unknown disturbances,a model-based boundary controller with the boundary disturbance observer is applied at the suspension platform to suppress the suspension platform oscillation and the rope vibration.An adaptive boundary controller is further designed to deal with model parameter uncertainties and unknown the upper bound of the disturbance,where the adaptive law updates the controller parameters online and the controller effectively suppresses the swing of the suspension platform and the rope vibration.The convergence and stability of the proposed controller for the closed-loop suspension system are verified by simulation.Finally,there will be some inevitable situations happen,such as an inclination of the suspension platform and the uneven distribution of the suspension rope tension during the static and dynamic operation process of the multi-rope parallel suspension system.Combining with Lyapunov theory,fuzzy system,nonlinear disturbance observer and the state feedback of suspension platform posture,an adaptive fuzzy backstepping controller is designed to leveling the posture of the suspension platform and balancing the distribution of the suspension rope tension.The convergence and the stability of the proposed controller for the closed-loop system of multi-rope parallel suspension are simultaneously verified by simulation.