Research On The Method Of Harmonizing Adsorption And Flexible Movement Of Underwater Wall-climbing Robots

The surface of a ship sailing for a long time produces various degrees of corrosion with marine attachment,which not only increase sailing resistance but also block the water filling nozzle of bottom equipment,affecting the normal operation of the ship,thus the ship must be tested and cleaned at fixed period.As the ship drive or park in the sea all the year round and its surface has good permeability,its adsorption approach of the underwater wall-climbing robot is mainly magnetic adsorption.Magnetic adsorption wall-climbing robot has difficulty in the coupling of adsorption and movement.Increasing the magnetic adsorption results in poor mobility,while increasing the flexibility of the movement reduces its magnetic adsorption.To address this problem,the adsorption movement mode of permanent magnet embedded on track has been developed to permanent magnet-wheel adsorption movement and some present adsorption modes,including suspension magnetic adsorption wheel type,electromagnetic adsorption foot type,the adsorption of a combination of negative pressure and permanent magnetism and so forth.In this thesis,aiming at the problem that the adsorption and motion of the magnetic adsorption wall-climbing robot is difficult to coordinate,the flexible motion characteristics of the magnetic wheeled wall-climbing robot and the strong adsorption force characteristics of the tracked wall-climbing robot are synthesized in order to design a wheel-tracked underwater ship wall-climbing robot.The wall-climbing robot is provided with magnetic adsorption by the adsorption unit of magnetic wheel and crawler.The main mobile mode is wheeled-walking,and the tracked-walking mode is supplemented.The research contents include: wheel-tracked structure,wall-climbing robot body and its underwater sealing design,mechanical modeling calculation under dangerous conditions,simulation analysis of magnetic force,dynamic modeling simulation analysis.After understanding the underwater environment of the ship's wall,the study analyzes the adsorption mode,movement mode and driving mode of the wall-climbing robot.A wheel-tracked mechanism is designed to coordinate the adsorption and motion performance of the magnetic adsorption wall-climbing robot.Then the underwater static and dynamic sealing are designed.The wall-climbing robot is adsorbed on the ship wall of any inclined angle in both water and underwater environments,and a static mechanical model of possible dangerous occasion is established,such as normal detachment,turning and sliding down the wall.A static mechanical model of inversion and magnetic wheel slip that may occur during accelerated motion is designed.The safe adsorption force basis of the wall-climbing robot is provided by numeric analysis.The three-dimensional static magnetic field characteristics of the magnetic ring and the wall surface and the adsorption unit and the wall surface are simulated,and the relationship between the magnetic field force of the wall-climbing robot and the change of the adsorption gap distance is analyzed,and the basis of the adsorption gap distance is provided.The dynamic model of wall-climbing robot is established.The dynamic force of the robot under different adsorption gaps is used to simulate the dynamics.The influence of magnetic force on its motion and the adhesion of the wheel are analyzed to verify the rationality of theoretical analysis.The relevant data of the movement characteristics of the wall-climbing robot with the change of the adsorption gap is provided,and the appropriate adsorption gap is selected to achieve the purpose of coordinating the adsorption and movement of the wall-climbing robot.