Optimal Guidance Law Based on Virtual Sliding Target

AbstractIn this paper, a new guidance law, which is called virtual sliding target (VST) guidance law, is designed based on the concept of the virtual target (VT). The presented law is applicable for short- and medium-range missiles. It is shown that by using proportional navigation (PN) and considering the aerodynamic characteristics of the missiles, this law leads to a better performance than the PN law. In this approach, motion of the VT is started from a position higher than the real target. By controlling the speed of VT, which slides toward a predicted intercept point (PIP), speed, position, and trajectory of the missile can be controlled. Since arrival times of the missile to the VT and the VT to the real target are equal, the collision will happen. Furthermore, a new optimal guidance law is presented for long-range missiles based on the concept of the waypoint (WP) and VT. In the mentioned law, there are two important points. The first one is a constant point that is called a waypoint and the second one is called a virtual target, which slides toward the PIP. Then a teaching-learning–based optimization (TLBO) algorithm is used to find the optimal initial position of the WP and the VT to maximize the intercept speed. Simulation results illustrate better performance of the VST law over the PN law in terms of the intercept speed.