Transversal Vibration Control Of Mono Chain Ropeway System

The single chain cargo system is proved to be flexible and efficient in mountainous terrain, which can meet the demand of cargo transportation in mountain orchard. The traction chain axially moves in a non-steady-state and inevitably produces periodic transverse vibrations. The wind excitation, polygon effect, variable tension and some other unsure conditions of the moving chain make the vibrational excitation more complexity. The transversal vibration of the moving chain may affect the safety and reliability of the ropeway system, and even lead to a disaster.In this thesis, the transversal vibration control of mono chain ropeway in mountain orchard was investigated. The Hamilton principle was applied to construct the differential functions of the mono moving chain and the right boundary actuator in one span. And the differential equations were discretized and solved by using the Crank-Nicolson and four order Ronge-Kutta methods. The results of MATLAB numerical simulation show that the numerical method is effective for solving complex vibration differential equations of the moving mono chain.In order to study the effect of lateral wind excitation on the transversal vibration of orchard chain ropeway system. The vibration properties of the axially moving chain under different speeds of steady wind and types of time-varying wind were numerically simulated and analyzed. An experiment set-up and an image acquisition device were designed for wind excitation test and the results showed that the lower wind speed can result in a decreasing amplitude of transversal vibration and show a convergence trend. The periodic excitations of the pulsing and sinusoidal pulsating wind have certain influence on the vibration amplitude.Considering the influence of polygon action that occurs when the chain links engagesthe supporting rollers, the model functions were modified. The transversal vibration suppression control laws that under uncertain and certain disturbances caused by the boundary polygon effect were respectively designed based on Lyapunov stability theory.The simulation results showed that the control law was effective to suppress the transversal vibration of the moving chain. The vibration of the controlled moving chain can vibrate under a very small and safe constant when the disturbance is unsure, and turn to zero quickly when the disturbance is certain. The proposed vibration control actuator was based on the structure characteristics of the ropeway system and the demand of the control law.The experimental results demonstrated that the control laws are effective with the vibration control actuator.The uncertainty of the chain tension, equivalent density and damping coefficient of the actuator were taken into consideration. Meanwhile the effect of tension on amplitude of transversal vibration was introduced to the design of a coupling controller. The coupling control system consisted of a right boundary actuator for vibration control and an automatic adjustor for tension control based on fuzzy and PID methods. The adaptive control algorithm was utilized to obtain the right boundary control law and its effectiveness was verified by numerical simulation.This thesis can provide a reference for the vibration control and stability analysis of moving chain system. It also has a significant theoretical and practical value for the study of suspension structure.