A new form of the Proportional Navigation (PN) guidance law for short-range homing missiles is proposed. Named the Switched Bias Proportional Navigation (SBPN) law, it is derived by invoking sliding-mode control theory and is structured around the basic PN, with an additive switched bias term. This additional term depends only on the polarity of the line-of-sight rate, which is readily available with a seeker. It is shown that the bias term acts as an estimate of the target acceleration and other unmodeled dynamics. An adaptive procedure is suggested to select the gain of this term, which results in improved performance. The SBPN is almost as simple to implement as the PN law itself, as it does not require any additional information related to the engagement, in the form of either measurements or estimates. Simulation results show that the acceleration profiles of SBPN closely follow those of augmented PN guidance law, after a short initial transient. They further demonstrate the robustness of the proposed SBPN in the presence of missile velocity variation.

No abstract

No abstract

Two new guidance laws for short range homing titissiles are developed by invoking the Sliding Mode Control (SMC) theory. Guidance law 1 is structured around the basic Proportional Navigation (PN), with an additive switching term, which is a function of the Line of ,Sight (LOS) rate alone. A n adaptive procedure is suggested to select the gain of the switching term, in order to reduce chattering. This guidance law is nearly as siinple to implement as the P N itself and does not require any explicit target maneuver estimation. Guidance Law 2, based on a first order sliding surface, is designed such that it results in a continuous acceleration law, thereby wducing the chatiering problem. While ezplicitly taking into account the effect of aerodynamic drag, it requires the second derivatives of LOS angle and range, which are not directly weasured. A n estimation scheme, again based on sliding mode theory, is presented to estimate these quantities. Sirnulation results clearly demonstrate the superior performance of these schemes.

No abstract

No abstract

No abstract

No abstract