Terminal Time and Angle-Constrained Nonlinear Intercept Guidance
For missile guidance systems, this work provides a method to meet two terminal constraints with a single control input, though it is incremental over existing sliding mode approaches.
This paper develops a hierarchical sliding mode guidance law to simultaneously control an interceptor's impact time and impact angle using lateral acceleration as the sole input, addressing underactuated nonlinear kinematics. Simulations demonstrate efficacy for stationary and constant velocity targets.
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.