Research On The Adaptive Trajectory Tracking Control For Underactuated AUV

In the field of marine engineering,autonomous underwater vehicle(AUV)have received increasing attention as a highly mobile and versatile underwater operating platform.The motion control technology of AUV is the basis for accomplishing various tasks,and trajectory tracking control is a hot topic in the field of AUV motion control.It has important significance and application value for maneuvering target tracking,time-sensitive target striking and formation cooperative operation.In this paper,the underactuated AUV is taken as the research object,the trajectory tracking control is taken as the research objective,and the nonlinear control theory and method are used as the research tools,and then the research is carried out.The main research contents are as follows:Firstly,the establishment of the motion mathematical model of underactuated AUV is introduced based on the relevant literatures.Then,the mathematical model of AUV is rationally simplified according to the characteristics of the research object,and the control simulation model of underactuated AUV is obtained.At the same time,the essential characteristics and control characteristics of underactuated AUV are discussed comprehensively.Secondly,for two typical underwater operation control problems,the horizontal trajectory tracking control and vertical surface depth tracking control of underactuated AUV are studied separately.The integrated sliding mode control method is used to design controllers and realize the horizontal trajectory tracking control and depth tracking control of underactuated AUV respectively.The simulation results are fully compared with the general backstepping controller and the control effect is also analyzed.This part lays the foundation for the subsequent three-dimensional trajectory tracking research.Thirdly,the problem of three-dimensional trajectory tracking control under the influence of model parameter perturbation of underactuated AUV is studied.A virtual velocity control strategy is proposed,and the trajectory tracking controller is designed based on bio-inspired neurodynamics model and adaptive integral sliding mode control.The proposed controller can avoid the jump of virtual control variables easy occurred in general backstepping control and effectively restrains the influence of model parameter perturbation.Numerical simulation shows that the proposed controller is not only effective,but also has smooth control outputs and robustness.Finally,the three-dimensional trajectory tracking control of underactuated AUV under the combined effects of model uncertainties and bounded current disturbances is studied.The virtual velocity control strategy is adopted,and dynamic surface control is used to filter the virtual velocity command,which reduced the computational complexity of the controller.The RBF neural network is used to estimate the uncertainty of the model,then the adaptive law of ocean current disturbance and the dynamic control law and are designed by integrating sliding mode control.Finally,a robust adaptive trajectory tracking controller is obtained.Compared the proposed controller with filtered backstepping controller in the same simulation conditions,the effectiveness,robustness and superiority of the designed controller are fully illustrated.In the conclusion of this paper,a comprehensive summary of the research work on the dissertation is carried out,and the existing deficiencies in this paper are objectively analyzed.At the same time,the future development of the field is also prospected.