Design of Fixed-Time Convergent Sliding-Mode Guidance Law with Impact Angle Constraints

Abstract

AbstractAiming at intercepting maneuvering targets at the end, a new attack angle constrained guidance law is proposed, using a fixed-time terminal sliding mode control (TSMC) method. Firstly, a new fixed-time convergent non-singular terminal sliding-mode surface (SMS) is introduced, which solves the singularity problem of traditional SMS. And at a fixed-time, the SMS, the line-of-sight (LOS) angle as well as the LOS angular rate are able to quickly converge, ensuring the finite convergence time. Besides, the upper bound is not affected by the initial value. Secondly, the maneuvering motion of the target is regarded as a disturbance in the guidance law, which could be estimated and compensated by a Linear Extended State Observer (LESO). In this way, the precise interception of the maneuvering target by the guidance system could be realized. As a final point, the utility of the guidance law designed becomes affirmed by simulation experiments, which demonstrates that the maneuvering targets can be attacked at different attack angles.KeywordsImpact angle constraintTMSCLESOFixed-time convergence