Adjustable impact-time-control guidance law against non-maneuvering target under limited field of view

Abstract

This article proposes an impact-time-control guidance law that can keep a non-maneuvering moving target in the seeker’s field of view (FOV). For a moving target, the missile calculates a predicted intercept point (PIP), designates the PIP as a new virtual stationary target, and flies to the PIP at the desired impact time. The main contribution of the article is that the guidance law is designed to always lock onto the moving target by adjusting the guidance gain. The guidance law for the purpose is based on the backstepping control technique and designed to regulate the defined impact time error. In this procedure, the desired look angle, which is a virtual control, is designed not to violate the FOV limit, and the actual look angle of the missile is kept within the FOV by tracking the desired look angle. To validate the performance of the guidance law, numerical simulation is conducted with different impact times. The result shows that the proposed guidance law intercepts the moving target at the desired impact time maintaining the target lock-on condition.

Sliding mode–based simultaneous control of impact angle and impact time

“…On substituting for _ σ t in (20), _ σ a in ( 21), _ λ a in (22), and _ t go in ( 13) into (30), we have…”

“…On the other hand, the guidance strategies for ensuring target interception at the desired impact time were also designed using various control techniques, such as the Lyapunov stability theory, 14 the feedback linearization, 15 the sliding mode control, 16–18 adaptive control, 19 and backstepping control. 20 In Ref. 14, the guidance strategies based on Lyapunov stability theory were proposed for both two-dimensional as well as three-dimensional engagements against stationary targets.…”

“…In Ref. 20, the desired look angle was chosen as a virtual control and designed to maintain the FOV limit. Then a backstepping-based guidance law was developed to tracking the look angle and regulate the specified impact time error.…”

Look angle tracking based three‐dimensional impact time control guidance law with field‐of‐view constraint

“…By designing a switching surface as the error between the desired and actual look angles, an ITCG law was derived in Reference 22, and its implementation involved the numerical solution of an algebraic‐trigonometric equation. By virtue of controlling the look angle dynamics during engagement, ITCG laws were proposed in References 6,23,24. The aforementioned ITCG strategies that do not involve time‐to‐go estimation can avoid the error and complexity caused by computing time‐to‐go.…”

Unmanned Aerial Vehicle Target Tracking Based on OTSCKF and Improved Coordinated Lateral Guidance Law

“…It guides the UAV on curved trajectories by tracking the specified reference point on the path. Lee et al [14] proposed a backstepping-based control technique for tracking moving targets, which is designed to eliminate impact time error. Park et al [15,16] described a globally asymptotically stable guidance law.…”