Research On Trajectory Tracking Control Of UUV To Moving Target Under Unknown Steady Current

Unmanned Underwater Vehicle trajectory tracking control technology(UUV)is the key technology to complete many underwater tasks such as dynamic docking recovery,hostile intelligence collection and time-sensitive strike,which has high scientific research value in both engineering application and theoretical research.Considering that UUV is affected by unknown steady current disturbance and model parameter perturbation when performing the moving target tracking task,a moving target trajectory tracking controller is designed based on sliding mode control insensitive to internal and external disturbances and the backstepping design idea to realize UUV moving target trajectory tracking under unknown steady current disturbance.In this paper,the trajectory tracking control of UUV moving target under unknown steady current is studied as follows:First,the modeling of UUV and maneuvering targets is discussed.The transformation relationship between the fixed coordinate system and the satellite coordinate system describing the motion of UUV is analyzed,and the six-degree-of-freedom spatial kinematics equation and dynamics equation of UUV are established in combination with the motion characteristics of UUV and the stress in fluid.This paper analyzes the mobility of ocean moving bodies and establishes several typical moving models of moving targets.Secondly,the target state estimation method based on Kalman filter theory is studied.This paper introduces the basic principle of Kalman filtering method,analyzes its limitations,further introduces the extended Kalman filtering method and unscented Kalman filtering method,designs a comparative simulation experiment,and analyzes the results of the comparative simulation experiment.Considering the limitations of the single model-based filtering method,an unscented Kalman-based interactive multi-model filtering method is used to complete the estimation of moving targets,and the simulation experiment is designed and the experimental results are analyzed to verify the effectiveness of the method.Thirdly,a planar trajectory tracking controller is designed for moving objects in the planar region.A virtual UUV with the same structure as the controlled object is used to design a plane trajectory tracking guidance law,and then the trajectory tracking plane error equation of UUV moving target is established.Using sliding mode control combined with backstepping design idea,a planar moving target trajectory tracking controller is designed.According to Lyapunov stability theory and related theorems,the stability of the closed-loop control system is analyzed.Simulation verification tests are designed and experimental results are analyzed to verify the feasibility and effectiveness of the controller.Finally,a space trajectory tracking controller is designed for moving objects in the space region.The planar trajectory tracking guidance method is extended to three-dimensional space.Under the idea of backstepping design,an integral sliding mode control method is used to design space moving target trajectory tracking controller with double closed-loop structure.According to Lyapunov theory and related theorems,the stability of the closed-loop control system is analyzed.Considering the existence of unknown steady current disturbance and UUV model parameter perturbation,simulation verification tests are designed and the experimental results are analyzed to verify the effectiveness and robustness of the controller.