In this article, fixed-time cooperative guidance laws are designed for multiple missiles to simultaneously attack a maneuvering target at desired terminal angles. The 3-D guidance commands consist of tangential acceleration along line-of-sight (LOS) direction to achieve a salvo attack and normal acceleration perpendicular to the LOS direction to realize a terminal angle-constrained interception. First, the tangential acceleration is derived from a distributed cooperative protocol to guarantee the fixed-time consensus of impact times for multiple missiles. Second, based on the integral sliding manifold and fixed-time reaching law, the normal acceleration is developed for each missile to converge the LOS angle to the desired value within a fixed time. In particular, the unknown target acceleration components are estimated by fixed-time observers and compensated in the guidance commands. The fixed-time stability of the proposed cooperative guidance law is rigorously proved and the explicit estimate for the convergence time is theoretically provided. Then, the proposed methods are utilized to realize the cooperative mission in the planar guidance scenario. Finally, the effectiveness and advantages of the proposed cooperative guidance laws are demonstrated through numerical simulations with comparative studies.

This paper proposes a varying-gain proportional navigation guidance (PNG) law that can serve as the baseline for precise control of impact time. First, a varying-gain PNG law is developed by an inverse design strategy from the explicit time-to-go estimation of the conventional PNG law, which leads to high control efficiency and accurate time-to-go prediction. Next, to show its potential significance, the varying-gain PNG law is augmented with a biased feedback command to obtain an impact time control guidance (ITCG) law. As a step forward in more practical applications considering missile speed variation induced by thrust, drag, and gravity, another ITCG law is derived from an efficient time-to-go prediction method by taking the exact trajectory-to-go as the independent variable. Further, the varying-gain PNG law and the planar ITCG laws are extended to the three-dimensional guidance scenario by steering the missile to fly on an engagement plane. Compared with similar existing results, the proposed ITCG laws based on the varying-gain PNG law do not involve any linearized approximations in the derivation, and thus possess higher impact precision, wider feasible region, and less energy consumption. Finally, several numerical simulations are performed to support the analytical findings.

This paper proposes distributed cooperative guidance laws for multiple missiles with constant speeds to achieve impact-angle-constrained salvo attack against a stationary target in both two-dimensi...

In this paper, a distributed three-dimensional (3D) nonsingular cooperative guidance law is designed for multiple missiles with different seeker’s field-of-view (FOV) constraints to achieve salvo a...

This paper investigates the three-dimensional (3D) spatial–temporal cooperative guidance problem for multiple missiles with time-varying speeds, which is addressed by a progressive design strategy. First, the zero miss distance and desired impact directions are realized by a 3D vector impact angle control guidance (IACG) law whose time-to-go is predicted accurately and efficiently by a numerical algorithm. Then, by introducing an implicit trajectory-to-go function, the time-to-go control mechanism is clearly revealed under missile speed variation. Accordingly, a coordinated biased term is added to the 3D vector IACG law to ensure a simultaneous attack. Finally, considering the seeker’s field-of-view (FOV) limit, the resultant cooperative guidance law is further augmented by another biased term to prevent the lead angle from exceeding its upper bound. Unlike similar existing results, the proposed one can satisfy multiple complex spatial–temporal constraints without active speed control, thereby manifesting great practical significance. Several numerical simulations are provided to show the effectiveness and advantages of the proposed cooperative guidance law.