A Study On Lateral Pitching Coupling And Stability Of "Haiyan-Ⅱ" Underwater Glider

The underwater glider is a new type of unmanned underwater vehicle.Its working principle is driven by buoyancy.It has strong endurance,low cost and low noise.Most underwater gliders have a range of several thousand kilometers.Due to the eccentric mass adjustment mechanism,there is a coupling between the roll and pitch attitude of the underwater glider.In order to achieve precise control of the underwater glider movement,the coupling effect of roll and pitch attitude must be considered.In this study,the research object was the “Haiyan-Ⅱ” underwater glider developed by Tianjin University.A decoupling controller based on LSSVM inverse system was first designed to solve the coupling problem.Then the stability of the longitudinal profile motion and steady spiral motion under the decoupled control condition of decoupling is analyzed.Finally,the stability of longitudinal profile motion and steady spiral motion under the decoupled control condition of decoupling is analyzed.The main research content and results of the thesis are as follows:1.To use the dynamic theory to construct developed the coupling dynamics of the roll and pitch attitudes for dynamic model of the “Haiyan-Ⅱ” underwater glider and demonstrated its coupling phenomenon by simulation,analyze its movement performance,provide the coupling problem of roll and pitching attitude of underwater glider,and confirm the existence of the roll and pitching attitude problem by based on analyzing the sea-trial data.2.Based on the roll and pitching attitude problem.The decoupling controller for the “Haiyan-Ⅱ” underwater glider was designed by the combination of LSSVM and inverse system methods.The simulation analysis,it is confirmed that the effectiveness usage of LSSVM decoupling controller is efficient in decline reducing or eliminating the coupling of the roll and pitching attitudes.3.To analyze the motion stability of the “Haiyan-Ⅱ” glider under the decoupling condition,and the results show that the space motion stability is quite well under the decoupling condition.