Three-dimensional optimal impact time guidance for antiship missiles

Introduction: The primary objective of missile guidance laws is to drive the missile to intercept a specific target with zero miss distance. Proportional navigation guidance (PNG) has been proved to be an efficient and simple guidance algorithm for missile systems, thus showing wide applications in the past few decades [1]. The optimality of PNG was analyzed in [2] and its extension to three-dimensional (3D) scenario can be found at [3]. In the context of modern warfare, many high-value battleships, like destroyers and aircraft carriers, are equipped with powerful self-defense systems against anti-ship missiles [4]. In order to penetrate these formidable defensive systems, the concept of salvo attack or simultaneous attack was introduced: many missiles are required to hit a battleship simultaneously, albeit their di.erent initial locations. One typical solution of simultaneous attack is impact time control guidance. Generally, impact time control can be classified into two categories: (1) specify the desired impact time and control each missile to satisfy the desired impact time constraint individually; and (2) synchronize the impact time either in a distributed or decentralized fashion through a communication network among all interceptors

Composite finite‐time convergent guidance law for maneuvering targets with second‐order autopilot lag

This paper aims to develop a new finite‐time convergent guidance law for intercepting maneuvering targets accounting for second‐order autopilot lag. The guidance law is applied to guarantee that the line of sight (LOS) angular rate converges to zero in finite time and results in a direct interception. The effect of autopilot dynamics can be compensated based on the finite‐time backstepping control method. The time derivative of the virtual input is avoided, taking advantage of integral‐type Lyapunov functions. A finite‐time disturbance observer (FTDOB) is used to estimate the lumped uncertainties and high‐order derivatives to improve the robustness and accuracy of the guidance system. Finite‐time stability for the closed‐loop guidance system is analyzed using the Lyapunov function. Simulation results and comparisons are presented to illustrate the effectiveness of the guidance strategy

Performance of 3D PPN against arbitrarily maneuvering target for homing phase

The performance analysis of the 3-D pure proportional navigation (PPN) guidance law was traditionally conducted by considering the cross-coupling effect of two independent 2-D PPN laws in the pitch and yaw planes. This could increase the complexity of the analysis and lead to conservative analysis results, especially when the target has maneuverability. To mitigate this issue, this article theoretically analyzes the performance of 3-D PPN directly on a rotating engagement plane using a Lyapunov-like approach. Considering practical issues, the analysis includes not only capturability, but also upper-bounds of heading error, line-of-sight rate, commanded acceleration, and closing speed. The analysis results obtained are also demonstrated by using numerical simulation examples. Compared to the previous studies providing the least conservative results, the analysis procedure is significantly simplified and the results are proven to be more practical and less conservativ