Research On The Motion Control Of The Vertical Surface Of A Small Autonomous Underwater Vehicle

Autonomous Underwater Vehicles as a maritime force multiplier,has a broad and important military purposes,have an irreplaceable role in the future of naval warfare.The control design of unmanned underwater vehicles is an important area of control system design.methods.Due to the nonlinear dynamic characteristics,the uncertainty of the model and the difficulty of measuring or estimating the interference usually result in difficult control.This paper studies a small underwater vehicle vertical control problems due to multiple variables underwater vehicle nonlinear model of coupling and parameter uncertainty,Especially,the influence of additional mass and damping coefficient on the control of underwater vehicle is very complicated,The model is decoupled,the kinetic parameters are simplified,and the model is reconstructed.The dynamic sliding mode control and the adaptive mechanism are used to construct the dynamic sliding mode adaptive controller,which can make the system be in the process of control.The uncertain parameters of the system are dynamically estimated to eliminate the expansion of the differential term caused by the backstepping method to achieve the desired control effect.First of all,Underwater vehicle platform.According to the performance requirements,follow the "C-Sweep" on the underwater vehicle mechanical appearance,control system structure,hardware and software system design,appearance according to force simulation to achieve the optimal shape.The control system is divided into four levels of task layer,navigation layer,control layer and AUV entity,to ensure the completion of underwater multi-task objectives.Hardware using industrial computer,communication module,DSP embedded host,etc.,can work in complex environments and high accuracy;software using VC6.0 compiler environment,easy to data processing and preservation,so that information exchange has a complete,stable,high efficiency surroundings.Secondly,Model establishment.Based on the relationship between the inertial coordinate system and the body coordinate system,the kinematics model of the five-degree-of-freedom of the underwater vehicle is established.According to the underwater vehicle force analysis,the kinetic model is obtained,The mathematical model of the underwater vehicle is obtained by combining the kinematic model with the kinetic model.The model is based on the motion plane decoupling method,which is equivalent to the system interference problem,such as modeling dynamic and external environment interference.The model gets the dip angle model and the depth control model.Finally,Motion controller design.The trim angle and depth control were designed pitch controller and depth controller based on the dynamic surface sliding mode and adaptive combination to research the vertical plane.Two schemes are designed to compare the depth control,simulation,results verify the depth and pitch control strategy not only limit on the trim angle,but also reduce the adjusting time,so the stability and AUV security is guaranteed.