Adaptive Sliding Mode Guidance Law with Terminal Impact Angle Constraint

Abstract

Aiming at the requirements of some guided weapons with attack accuracy and terminal attack angle constraint, an adaptive sliding mode guidance law with terminal impact angle constraint is proposed based on sliding mode variable structure control theory. This guidance law chooses the angular rate of the line of sight as the sliding mode, introduces the angular constraint, regards the target maneuvering as limited disturbance, and the stability of the guidance law is analyzed by using Lyapunov theory. In the meanwhile, the chattering phenomenon is substantially weakened by the combination of variable switching term and saturation function. Finally, the simulation is made by applying the guidance law to the missile real model, and the results show that compared with traditional algorithm, the designed guidance law can hit the target with less miss distance and impact angle error.