Impact Time Constrained Sliding Mode Guidance with Prescribed Performance

Abstract

This paper proposes a sliding mode control-based guidance scheme that guarantees the interception of the stationary target at a desired terminal time. Guidance command is derived to ensure that the error in time-to-go remains within its prescribed performance bounds, converges to zero before target capture, and leads to a successful interception of stationary targets at a desired terminal time. Owing to the use of time-to-go approximation that does not depend on small angle assumptions about interceptor heading angle error and the derivation of guidance command using nonlinear kinematics, the designed guidance scheme remains effective even for large initial heading angle errors of the engagement. The sliding mode control combined with the prescribed performance function is used to derive the guidance command, and the stability of the designed scheme is analytically shown using the Lyapunov stability theory. The proposed method guarantees a desired transient performance for the interceptor’s time-to-go and time-to-go error approaches the origin in a finite time, resulting in the achievement of guidance objectives. Numerical simulations are performed to show the effectiveness of the designed guidance strategy for different initial engagement geometries and desired impact times.