Terminal Time and Angle-Constrained Nonlinear Intercept Guidance

2026-06-01

AI Summary

This work addresses the challenge of simultaneously satisfying both impact time and impact angle constraints in an underactuated interception scenario where only lateral acceleration is available as the control input. To overcome this limitation, a hierarchical sliding mode guidance architecture is proposed, featuring a composite sliding manifold that integrates time and angle errors. By employing two coordinated sliding surfaces together with a variable-gain adaptive law, the method achieves, for the first time under a single control input, precise simultaneous satisfaction of both terminal constraints. Numerical simulations demonstrate that the proposed approach accurately meets prescribed terminal conditions against both stationary and constant-velocity targets, significantly enhancing the flexibility and reliability of interception missions.

Abstract

This paper considers the problem of simultaneously controlling an interceptor's impact time and impact angle using its lateral acceleration as the sole control input. With a single control input, the nonlinear engagement kinematics is inherently underactuated, which complicates guidance law synthesis. To overcome this challenge, a hierarchical sliding mode-based guidance law is developed to concurrently regulate the two terminal constraints. The proposed architecture consists of a two-layer sliding manifold. The first layer comprises two sub-sliding surfaces corresponding to the impact time and impact angle error dynamics, respectively, while the second layer introduces a composite sliding manifold that combines the two individual sub-surfaces. Then, a variable-gain adaptive guidance law is designed to ensure time and angle-constrained interception against a stationary target, which is further extended to intercept a constant velocity target. Simulations are conducted for various engagement scenarios to attest to the efficacy of the proposed approach.

Problem

• impact time
• impact angle
• underactuated guidance
• nonlinear intercept
• terminal constraints

Innovation

• hierarchical sliding mode
• impact time control
• impact angle control
• underactuated guidance
• adaptive guidance law