The Reserch Of Modeling Method For Deep Sea Work-Class ROV

Along with the reduction of the resources on the land,as new treasures,the development of the ocean catches more and more attention.As deep sea operating equipment,the Deep Sea Work-Class ROV plays an important role in the development of marineresources.Firstly,based on the force analysis of Deep-Sea Work-Class ROV,establish the models of the external forces separately,according to Newton's law,six degrees freedom of kinematics and kinetics were completed.Furthermore,on the basis of the nominal ROV model,build error model with model parameter uncertainty,further close to the actual ROV systems.Secondly,ROV is a time-varying nonlinear system.Coupling phenomenon between the various degrees of freedom is very serious.So the decoupling of ROV six DOF motion model is very necessary.This paper describes the three decoupling methods: single degree of freedom decoupling,plane motion-based decoupling and error model based decoupling.Three methods were derived in the form of the equations of motion ROV after decoupling,and compared their advantages and shortcomings.Thirdly,ROV stability analysis and verification of manipulation were conducted.According to well-established motion model,using Lyapunov stability method to validate the stability of ROV;Using single degree of freedom decoupling method,the ROV motion model was decoupled at the stationary state of suspension,and stability analysis was conducted;To test ROV maneuverability,according to ROV six DOF motion model,single degree level direct motion,vertical submersible floating,horizontal level rotary and three-dimensional spiral motion numerical simulation were conducted.According to the simulation results,the relevant manipulator parameters of ROV were obtained.Finally,controllers were designed to meet the features of six degrees of freedom of ROV.According to the characteristics of the various degrees of freedom,for axial and lateral,adaptive Backstepping sliding mode controller was adopted;for vertical and heading,adaptive Terminal sliding mode controller with nonlinear disturbance observer was adopted;for roll and pitch,PID controller was adopted.The derivation of associated controllers was addressed specifically,and the stability was proved by using Lyapunov method.Simulation experiments were conducted to verify the effect of the controller of individual freedom.Finally,multi-controllers joint control simulation was conducted to prove the effectiveness of the controllers for the ROV in three-dimensional motion control.