System Design And Experimental Research Of Underwater Dual-mode Robot

Underwater structures are usually damaged due to erosion by waves,currents,and aquatic organisms,so regular inspection and maintenance are required.To improve inspection and maintenance efficiency,ROVs and underwater wall-climbing robots can be used to replace divers for operation,but each has limitations.The former faces the control problem of long-term hovering stability in the dynamic wave environment,and the latter faces the problem of difficulty in overcoming obstacles.To solve the above problems,the paper proposes a new idea of a dual-mode operation robot,which enables the robot to have the ability to swim and climb walls.The robot will change attitude near the working point of the underwater structure and then adsorb to the wall to carry out crawling and working.If there is an obstacle that is difficult to surmount,the robot will directly detach from the wall and swim to the next working point adsorb again.Therefore,the paper researches the principle of underwater adsorption.Based on this,the robot system scheme design is carried out.Through fluid mechanics simulation verification and control system development,the prototype is finally built.The research is of great significance to improve the operation efficiency of underwater robots.The paper first selects an underwater Bernoulli adsorption method with propulsive and non-contact adsorption functions.Then carry out research on its principle,and verify its performance through experiments.On this basis,the design of robot system schemes and mechanical structures is carried out.According to the established three-dimensional model,the mathematical model of the robot is deduced and the associated hydrodynamic coefficients are solved through Fluent simulation to obtain the complete control equation.To ensure the reliability of adsorption,the influence of waves and water flow on the body is studied.Then the stable adsorption conditions of the robot on the wall are analyzed.To realize motion control,the low-level driver program and the upper-level control program are developed.Downgrade the deduced control model and decouple each attitude control channel,then the clamping PID method is used to realize the largeangle attitude control to meet the mode switching requirements.The accuracy of the control theory is verified by Simulink,and the system control parameters are obtained.According to the design scheme and theoretical derivation,the construction of the robot prototype system is completed.To ensure the accuracy of the motion control function,functional tests were carried out in the laboratory pool environment and the reservoir dam environment.Experimental results show that the robot system developed can meet the set functional requirements and achieve the expected design goals.