Study On Design And Mechanical Characteristics Of Wall-climbing Derusting Robot

Economic globalization promotes the continuous progress of shipping industry and the development of shipping industry.The international ocean shipping exchanges are becoming more frequent.With the increase of the ship’s navigation time in the sea,the hull surface will be corroded by sea water or attached to marine organisms,resulting in reduced speed and reduced economic benefits.Therefore,the ship needs to often return to the dock for derusting treatment.For a long time,sandblasting and derusting by workers with spray guns is the main way to remove rust on the ship surface,which not only harms the health of workers,but also causes serious air pollution.In recent years,the combination of wall-climbing robot and highpressure water is gradually adopted to effectively solve the shortcomings of manual sand blasting rust removal.It is of great significance to the development of shipping industry,shipbuilding industry,and ship-repairing industry.In this thesis,according to the design goal of ship rust removal robot,the overall design scheme,mechanical performance analysis,tile-shaped magnetic unit and its structural mechanical properties,prototype mechanism and experimental study of a wall-climbing robot are completed.The main work and conclusions are as follows:(1)According to the working environment and design goal of the wall-climbing derusting robot,the model selection and structure design of the driving module,the walking module,the adsorption module,the obstacle-surmounting module and the cleaning module are carried out by adopting the modularization thought.A main body decoupling mode and its decoupling connection form with the cleaning plate are designed.The jet impingement force and vacuum adsorption force in the cleaning plate are analyzed,which provided the basis for the following mechanical properties analysis.The modeling and virtual assembly of each module of the robot are completed.(2)The static model of the working state and obstacle-surmounting stage of the robot is established.The results show that the anti-instability coefficient of the working state is 3.5.According to three types of obstacle-surmounting: driven wheel,driving front wheel and driving rear wheel,the analysis results show that the driving rear wheel obstacle-surmounting is more prone to instability,the anti-instability coefficient is 2.3.The robot motion model is established to solve the driving torque of the linear motion and the steering motion.The linear acceleration of the robot requires a driving torque of 84.8 N·m and a steering motion of 106N·m.The rationality of servo motor and reducer selection is verified.The dynamic model of the robot wall is established,and the velocity,the distance and the deflection angle of the steering motion are solved iteratively.The results show that after 3.1 s acceleration to 0.2 m/s,the motion distance of 6s is 2m.At an initial angular velocity of 0.75 rad/s,the robot deflects90 degrees after 3.5 seconds.(3)Based on the finite element software,the magnetic force and magnetic field intensity of the permanent magnet adsorption unit are analyzed.The results show that the Halbach magnetic circuit can effectively enhance the wall-attachment ability of the robot.The strength of channel steel has been checked and the factor of safety is 1.8.Aiming at the structuremagnetic field-nonlinear problem,the structural mechanical characteristics of channel steelpermanent magnet-tire are studied.The results show that the coupling deformation of channel steel increases by 50% and the coupling compression of tire by 63%.Compared with the experimental results,the error of tire compression is less than 7%.(4)According to the drawings of each module of the robot to purchase and process,the prototype of the production and assembly are completed.The experiment of magnetic force change and surrounding magnetic field of permanent magnet adsorption unit is completed in the state key laboratory of permanent magnet materials,and the error is less than 10%.The compression test of solid tire is completed,and the results verify the accuracy of the finite element simulation.The wall attachment and motion performance of the robot are tested on the vertical wall of the laboratory and on-site ship wall.The results show that the robot has good wall-attaching ability and motion performance.