An Experiment On Proportional Navigation

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Proportional Navigation For short-to-medium range homing missiles the most widely used law in practice is proportional navigation (PN) guidance. The missile acceleration should nullify the line-of-sight (LOS) rate between the target and interceptor that is basic philosophy behind PN. Originally, PNG law creates angular velocity or acceleration commands perpendicular to the LOS (line of sight). If two bodies are closing on each other eventually they will intercept when there is no rotation in the line of sight (LOS) between the two bodies relative to the inertial space. By making the interceptor missile heading proportional to the LOS rate for a non-maneuvering target the PN guidance law seeks to null out the LOS rate. More specifically, the PN guidance law seeks to null the LOS rate against non-maneuvering targets by making the interceptor missile heading proportional to the LOS rate. For instance, in flying a proportional navigation course, the missile attempts to null out any line-of-sight rate that may be developing. The missile does this by commanding wing deflections to the control surfaces. Consequently, these deflections cause the missile to execute accelerations normal to its instantaneous velocity vector. Thus, the missile commands g’s to null out measured LOS rate. As will be developed in the discussion that follows, this relation can be expressed as follows: V ̇_PNG=NV_λ λ ̇ (3.1) Where V ̇_PNG: The