Impact time constrained integrated guidance and control design

Abstract

This paper proposes integrated guidance and control design to intercept a target, which may execute various motions, at a pre-specified time of interception. The problem is addressed considering nonlinear engagement kinematics and the interceptor is steered using the combined effects of canard as well as tail configurations (dual-controlled interceptors). Different formulations of time-to-go, without the restrictive assumption of interceptor's small heading angle, have been used in deriving the guidance commands, allowing the proposed strategy to remain effective over a wide range of impact time values. A weighted effort allocation scheme, in canard and tail deflections, has been proposed to generate the required lateral acceleration. The overall design uses sliding mode control owing to its simplicity of design, while a nonlinear finite-time disturbance observer is used to estimate the target's maneuver. Finally, simulations are presented for various target motions, and time-constrained interception with an impaired actuator is also shown, vindicating the efficacy of the proposed technique.