摘要：This paper proposes an impact angle constrained guidance strategy based on sliding mode control. The proposed guidance strategy not only ensures the target interception at a desired impact angle but also ensures the alignment of interceptor in a desired impact direction within a predefined-time, whose least upper bound can be pre-fixed. Guidance command is derived using nonlinear engagement dynamics, after transforming the problem of impact angle control to that of tracking a desired line-of-sight angle and its rate. Proposed guidance strategy also guarantees the convergence of the controlled variables within a priori fixed-time, from almost all initial conditions. Due to the nonlinear design framework and choice of the controller, the possible difficulties due to linearizations are avoided and thereby proposed guidance remains applicable even for engagements with large heading errors. Numerical simulations validate the efficacy of the proposed guidance scheme for stationary and constant velocity targets, for different engagement geometries.
关键词：Guidance design;sliding mode control;impact angle;predefined time stability
