| Ships sailing in the sea for a long time will be attached to the bottom of the ship by a large number of marine organisms.These organisms not only accelerate the corrosion of metals,but also increase the ship’s navigation resistance,increase the fuel consumption and reduce the speed.What’s more,it may bring the invasion of alien species and break the local ecological balance,so it is very important to clean the hull regularly.At present,the cleaning of hull attachments in China is basically carried out in dry dock.The cleaning cost is high and the efficiency is low.Therefore,the research of underwater hull cleaning robot has great commercial value,and it is also necessary for national defense construction.Because the efficient underwater hull cleaning robot can shorten the time of warship in the dock and increase the service time.For the overall design of ship cleaning robot,this paper designs from two aspects of structure and control.In the aspect of structure,the main work is as follows:the strength and corrosion resistance of the framework and shell are analyzed,and the static analysis of the framework finite element is carried out;the structure of the adsorption module,the cleaning module and the walking module of the existing cleaning robot is analyzed,and a cleaning wheel with integrated motor and a higher integrated negative pressure adsorption module of cavitation water are optimized and designed,and the movement of the rotating nozzle is carried out Analysis;according to the requirements of the robot’s position and attitude change in the water,a kind of structure with five thrusters under DOF is designed;the gravity of the cable module is calculated and the buoyancy configuration is carried out to reduce the interference of the cable gravity on the motion of the cleaning robot;the buoyancy configuration is carried out according to the calculated coordinates of the weight and the buoyancy center to achieve the design goal of the weight and the buoyancy center are coincident and equal.In the aspect of control,the overall control scheme and human-computer interface are designed according to the operation of the robot.For the hydrodynamic performance problem,the fluid resistance value of the shell structure is analyzed and the shell is optimized.Through the establishment of numerical calculation model,the fluid resistance of the shell before and after optimization is calculated by FLUENT software,and the comparison shows that the optimized model can reduce the resistance of 17.534n at the speed of 1m/s.The results show that the maximum velocity should be less than 0.74m/s when moving near the wall and 1.2m/s when moving on the wall.For the motion control of the cleaning robot,this paper designs a trajectory tracking control method to realize the motion control on the surface.By establishing trajectory motion control,dynamic control and adaptive parameter control,the variable angle parameter of the surface is taken as the input of the control parameter to solve the problem of motion error caused by the shape of the surface.Through the simulation curve analysis,this method is obviously superior to the control method using depth sensor,and has good robustness.In addition to the theoretical analysis,this paper also carried out some prototype verification tests.Through the test of weight and buoyancy center,it is verified that the weight and buoyancy center are coincident and have zero buoyancy structure;through the test of adsorption force,it is verified that the stability of adsorption force can reach 305.3n when the adsorption distance is 2cm;through the attitude control test,it is verified that the propeller layout is reasonable;through the pull test,it is verified that the calculation value of fluid simulation;through the prototype real ship cleaning In the brush test,the cleaning quality can reach hpw2,and the cleaning efficiency can reach 1440 m2/h. |
