Bio-inspired Three-dimensional Trajectory Tracking Control Of An Underactuated UUV Based On Backstepping Control

Unmanned Underwater Vehicle(UUV)three-dimensional trajectory tracking ability is the realization of marine resources development,scientific survey,coastal defense and other applications of important technical foundation.However,UUV usually has underdriving,high coupling and non-linearity,coupled with external interference and also need to meet the time and space requirements,making UUV three-dimensional trajectory tracking control more difficult to achieve.In this paper,based on the bio-inspired model and the backstepping control method,the problems of singular value,motion parameter jump,tracking accuracy,anti-jamming,and control input saturation in underactuated UUV trajectory tracking control are studied.To achieve better tracking control effect.Specific research work is as follows:1.A six-degree-of-freedom motion model of UUV space is established,and the effects of strong non-linearity,constraint imperfection,high coupling degree,interval confinement and environmental disturbance on the controller design are analyzed.The mathematical model of bio-inspired is given and the characteristic analysis and simulation of this model are given.2.A dynamic velocity regulation backstepping control method based on the bio-inspired model is proposed.This method can avoid the singular value caused by the conventional backstepping method(the definition of virtual velocity variable instead of attitude error)when the heading angle error is plus or minus 90~o.In the simulation study,the singularity of the trajectory tracking control in the horizontal plane is designed.And the results show that the trajectory tracking control of underactuated UUV can be realized by using the proposed method.3.A method of designing controller based on backstepping control and three bio-inspired models is proposed.In this method,a three-dimensional dynamic velocity trajectory tracking controller is designed from the view of dynamics,which avoids the problem of constant external disturbance and the jump of motion parameters caused by the non-smooth trajectory;meanwhile,it can effectively restrain the problem of big trajectory error.The results show that the tracking control of underactuated UUV space trajectory can be achieved under the condition of external disturbances by using the proposed method.Simulation results show that the proposed method can achieve the tracking control of underactuated UUV space trajectory.4.A simplified control method for derivation of UUV three-dimensional trajectory tracking backstepping control is proposed.This method avoids the"differential explosion"caused by repeated derivation by using the derivative output value of the bio-inspired model instead of the real-time numerical derivation in the backstepping control.In the simulation study,the simplified calculation method is used to design three-dimensional line comparison simulation experiment,can avoid the control input saturation phenomenon.In this paper,the design of underactuated UUV space trajectory tracking controller based on the definition of virtual velocity variable instead of attitude error backstepping method is explored.The characteristics of the exploratory bio-inspired model are explored and the stability of the tracking system is guaranteed.Singular value problem,motion parameter jumping problem and"differential explosion"problem,which can effectively improve the control performance and tracking accuracy of the system,and make the simulation verification and research.