Precise Trajectory Tracking and Control for Guided Projectile Using Acceleration Guidance Logic

A nonlinear acceleration guidance command and an acceleration autopilot are designed in order to make the guided projectile track the complex curved trajectory precisely.Using the position coordinate and velocity of the guided projectile which is given by the GPS only and the coordinate of the reference point on the desired trajectory,the guidance command is obtained.Upon the guidance activation,the projectile starts to impact the reference point and the precise trajectory tracking is accomplished.The guidance and control approach separates the projectile guidance and control system into an outer guidance loop and an inner control loop.The acceleration autopilot is used in the inner loop and the nonlinear acceleration guidance command is used in the outer loop.The autopilot is designed using the variable structure control theory.In the presented simulations,the guidance and control system is used to track a curved trajectory.The simulation results show that the guidance segment and autopilot can make the guided projectile track the trajectory precisely.