Research On The Attitude Control And Trajectory Optimization In The Process Of Water-exit For The Submarine-launched Missile

Submarine-launched missile,as the most critical part of the trinity strike of the nuclear powers for every country,has a great military and strategic significance.The launching point of the submarine-launched missile can be randomness due to the submarine underwater high-speed maneuver.Meanwhile,the seawater can be a strong barrier to the transmission of electromagnetic waves,s uch that the radar cannot detect the submarine effectively.Therefore,the submarine-launched missile has the characteristics of formidable deterrence,flexible or nimble,strong penetration ability,high survival ability and accuracy.etc.However,there exist strong disturbances such as ocean currents,waves and sea breezes in the presence of underwater launch.Hence,the dynamic model in the process of underwater launch is more complex and hard to describe accurately.At the same time,there also exist strong nonlinearity,coupling and uncertainty,which put forward a large demand for the design of its attitude control system.In addition,it is necessary to optimize the submarine-launched missile trajectory after the launch of submarinelaunched missile in order to avoid the risk of submarine being smash ed.In this dissertation,the submarine-launched missile is studied focused on its underwater launch dynamics model,underwater attitude control,trajectory optimization and other issues.First,the position derivative and the rotation derivative are prese nted to describe the position force and damping force of the submarine-launched missile which solve the problem of dynamic model of submarine-launched missile in the process of its underwater motion.Moreover,the influence of the ocean currents,waves and sea breezes in the process of submarine-launched missile underwater motion is analyzed in detail and the disturbance mathematical model is also established.Furthermore,an analytic expression of the wave force with different wave levels is obtained by data fitting.The effluent length and the relative effluent length are developed to express the various parameters under the consideration of parameter variation in the effluent process.Hence,the underwater dynamics model for submarine-launched missile is proposed.Second,the small disturbance of dynamics model equations are linearized based on the underwater dynamic model of submarine-launched missile.The independent three-channel transfer functions are proposed,and the PID control system and control parameters are also designed.At the same time,a finite-time convergence active disturbance rejection control(ADRC)is studied and proved by Lyapunov theory in the case of large disturbances.Lastly,the 6 DOF simulation results are carried out under the interference conditions of 6 waves,ocean current,oceanic density and sea level wind.Finally,the first-class trajectory design method for submarine-launched missile is studied to avoid the abnormal thrust in the early flight stage.Meanwhile,the design solutions of flight scheme for the effluent trajectory are given and the optimal trajectory design model for the submarine-launched missile is also developed.This dissertation further studies the particle swarm optimization method and its improved methods to solve the problem of optimal trajectory design.The sensitivity analysis method is presented to analyze the influence of fault shutdown time,sensitivity of the initial state and effluent trajectory design parameters for the trajectory inclination and corresponding predicted range.The swarm optimization method is proposed to optimize and analyze the range of the furthest predict landing point.In addition,the optimal trajectory inclination is designed and the optimal launched trajectory flight procedure is also determined.