Research On The Trajectory Planning Of Rudder-guided Missile

Guided missile guidance stage includes the stages of midcourse guidance and terminal guidance,The middle guidance stage is the flight control stage of the projectile's active segment ending to the terminal guidance,It is necessary for that missile to travel through a predetermined space coordinate and have a predetermined velocity vector direction during flight.However,under the influence of initial disturbance and thrust eccentricity,the projectile will generate random trajectory deviation after the active segment is finished.The usual control method is the difference between the measured value of the ballistic elements and the standard trajectory as the control variable,and control projectile to fly according to the standard trajectory.But this flight control method requires that the measurement and control system can provide a large transverse overload,and the ability of the projectile storage speed is weak.The trajectory planning proposed in this paper is to design a flight path that satisfies the boundary value condition and cost function between the real-time coordinate and the target point of the projectile,the control rules obtained after the planning trajectory as the control method,and the demand for the control system of the projectile is lower,which is conducive to the overall design of the projectile.In this paper,the optimal control model of trajectory planning is established based on the flight characteristics of guided missile during the guidance phase and the minimum energy loss in flight.Firstly,based on the theory of ballistics,the trajectory equation of a controlled particle is established as the state equation of the ballistic programming variational problem,the boundary condition of the variational problem is the ballistic elements of the mid-guidance starting point and the mid-guidance ending point of the predetermined trajectory plan,the minimum energy loss in the mid-guidance flight is the cost function,Gauss pseudo-spectral method is applied to establish the optimal control model to solve the optimal planning trajectory.Second,ballistic trajectory measurement data will have some random noise,this paper established the optimal estimation and preliminary bulky noise eliminating kalman ballistic filter,can improve the filter convergence speed and accuracy.Different planning start time have different trajectories and different projectile speed.In this paper,the relationship between the initial time of planning and the velocity of the projectile is analyzed by using the numerical simulation method.The simulation results show that the initial time of planning has a great influence on the velocity of the projectile,and the range of the loss velocity of the projectile is about 10%.