Research On Three-dimensional Trajectory Control Of An AUV Based On Backstepping Sliding Model Algorithm

Autonomous underwater vehicles(AUV),as important marine tools explored and developed by human,have great prospects in military and civilian fields.The development of autonomous underwater vehicle control technology will become the focus of scholars.As everyone knows,the control system of autonomous underwater vehicles owns the properties of high nonlinearity,non-integrity,model uncertainty,external disturbance and so on.How to use the nonlinear control theory and intelligent control algorithm to solve the above problems,which has become a hot spot in the research field of autonomous underwater vehicle motion control.In this paper,three robust schemes are discussed for the control system of autonomous underwater vehicles.Firstly,a dynamic surface sliding mode control algorithm is designed for the control system of an autonomous underwater vehicle.The algorithm avoids the problem of "explosion of complexity" in the traditional backstepping method",but still does not solve the chattering problem in sliding mode control,meanwhile robustness of the algorithm needs to be improved.Secondly,a control method,which effectively reduces the problem of chattering in the traditional sliding mode control method,is designed by using dynamic surface control technology and second order sliding mode control method for the control system of autonomous underwater vehicles with uncertain disturbance.Finally,A MLP and dynamic surface second order sliding mode control algorithm is proposed for three-dimensional trajectory tracking control of autonomous underwater vehicle with model errors under external disturbance.An innovative neural network compensator is designed to counteract effects of modeling errors,meanwhile MLP technology is used to reduce the computational burden caused by the neural network,and further improves the robustness of the system.The robustness of the three algorithms is increasing in turn in this paper.Stability of the closed-loop system is guaranteed in all of the three algorithms,finally,MATLAB for simulation shows the effectiveness of the investigated algorithms.