Boundary Vibration Control For Flexible Systems

Due to the merits of the lightweight,low energy-consumption,flexibility,etc.,the flexible structure has been widely used in aerospace,robot,industry,marine engineering,etc.Nevertheless,the flexible structure is subject to external disturbances and generates structural vibration because of its characteristic.It has a significant influence on the structure’s performance,namely,shortening the lifespan of the structure,and even damaging the structure.Analyzing the dynamic characteristic and developing effective vibration control strategies are meaningful to improve the working efficiency and to decrease the accident.Recently,vibration control for the flexible structure is a popular topic in the control field.This paper aims to investigate the vibration suppression problem of four representable practical flexible systems,namely,industrial moving strip system,flexible Timoshenko arm system,crane system,and mooring system.For the industrial moving strip system described as an axial moving Euler-Bernoulli beam,a boundary control strategy is developed with considering the effect of the input dead-zone nonlinearity to reduce the transverse vibration of the strip.For the uncertain flexible Timoshenko arm system described as a rotatable Timoshenko beam.a robust adaptive boundary vibration control strategy is developed with considering the effect of the input and output constraints to achieve the deformation reduction and angular position tracking of flexible link.For the crane system described as a variable length string in two-dimensional spaces,by taking the output constraints into account,a cooperative boundary vibration control strategy is proposed to handle the longitudinal-transverse coupled vibrations of the cable.For the mooring system described as a multi-strings,a boundary control strategy is proposed based on the information of the platform to reduce the coupled vibrations of the mooring lines and to keep the position of the platform in the surface.Meanwhile,the feasibility and effectiveness of the developed vibration control strategies are validated with the theoretical analysis and numerical simulations.The research results will provide theoretical support and a feasible solution for the vibration control of the flexible systems in engineering.Moreover,they will also be used to the research for similar issues in the relevant fields.