UUV Visual Simulation With Trajectory Tracking And Formation Control

The detection and protection of marine resources have become increasingly important in today’s world situation.Unmanned Underwater Vehicle(UUV)has advantages such as low cost,small size,light weight,strong flexibility,and high reliability,making it an important tool for marine environmental operations.Ensuring the stable operation of UUV underwater and the stability of combined operations has become focused.The paper aims to build a visual simulation system for underactuated UUV motion control,eliminate the risks of UUV underwater testing,provide a repeatable experimental environment,improve the efficiency of UUV technological development,and validate the designed trajectory tracking controller and formation controller.Firstly,a space coordinate system is established to describe the motion of the underactuated UUV,with 5-degree of freedom kinematics model and dynamic model of the underactuated UUV are established using geometric method and Newton-Euler equations.Considering the impact of current speed on the motion of the UUV,a motion model of the underactuated UUV under current disturbances is established.Secondly,in order to improve the robustness of underactuated UUV trajectory tracking under current disturbances,a current observer is designed to estimate the constant current velocity.A trajectory tracking controller is established based on the Backstepping,and a firstorder low-pass filter is designed in the system’s Backstepping to solve the differential explosion problem of the Backstepping and eliminate high frequency signals.The Lyapunov stability theory is used to prove that the designed trajectory tracking controller is uniformly ultimately bounded.The simulation has verified that the designed controller can reduce the impact of ocean current disturbances and UUV is drived to move stably along the trajectory.Then,considering that the underwater acoustic communication network has time delay and the state information of the leader UUV received by the follower UUV has lag,which affects the motion of the whole formation.Therefore,a double closed-loop integral sliding mode controller is designed to improve the robustness of the whole formation.For the underwater acoustic communication delay,the extended Kalman filter algorithm is used to predict the state information of the leader UUV and reduce the impact of underwater acoustic communication delay on formation control.The stability of the formation controller has been proven and simulation has verified that the designed formation controller can reduce the impact of underwater acoustic communication delay on formation motion.Finally,to reduce the risk of underactuated UUV underwater testing and provide a repeatable experimental environment,Unity is used to design a visual simulation system for underactuated UUV motion control.Virtual reality technology is used to build a threedimensional underwater environment,and scripts are written to achieve trajectory tracking controller and formation controller.The designed visual simulation system is tested,which verify the stability of the designed trajectory tracking controller and formation controller for underactuated UUV motion control.