Three-dimensional impact angle control guidance with field-of-view constraint

Traditional analytical impact angle control guidance laws with field-of-view (FOV) constraint were studied in two-dimensional cases. This paper deals with this problem in a three-dimensional engagement scenario by proposing a new nonlinear non-switching guidance strategy for attacking a stationary ground target. The nonlinear relation of the two partial lead angles of the missile is decoupled, and the guidance strategies for a vertical impact case and a non-vertical impact case are studied, respectively. The design problem is converted to be the nonlinear tracking control issues of yaw and pitch subsystems with partial state constraint. Novel model transformations are introduced to the two subsystems based on the properties of sine function and hyperbolic tangent function, then the guidance laws are derived by utilizing nonlinear mapping-based backstepping technique. It is proved with Lyapunov approach that the missile line-of-sight angles can be regulated to the desired ones for impact angle control, and that the overall lead angle is always restricted within the prescribed region for FOV limit as well as it converges to zero eventually for homing constraint. Simulation results show that the missile can impact the target from various desired directions successfully without violating FOV limitation. (C) 2020 Elsevier Masson SAS. All rights reserved.