Guidance Law Design Against Unknown Maneuvering Target Based on Two ESOs

With the development of high maneuvering missiles and hypersonic maneuvering unmanned aerial vehicles, accurately intercepting such high-speed moving targets typically involves knowing the target's precise velocity and acceleration. Obtaining the velocity and acceleration of the target in real time is difficult and expensive in practice. On the other hand, developing a guidance law for maneuvering target with unknown velocity and acceleration is still a work in progress. This paper proposes three types of sliding-mode guidance rules based on two extend state observers (ESOs) for intercepting maneuvering targets with unpredictable velocity and acceleration, where the only information required is the LOS angle and distance, but not the LOS angle velocity or the relative velocity orthogonal to the LOS. To estimate the unknown things associated to the objective, two ESOs are built. The auxiliary signal system has been devised to compensate for the saturation constraint of the guidance command. To test the effectiveness and robustness of the proposed guidance legislation, numerical simulations are run with a non-moving target and a maneuvering target.