Abstract:

A novel three dimensional (3D) nonlinear pseudo optimal sliding mode guidance law for hypersonic vehicle is proposed to resolve the motion coupling and parameter perturbation problems. Firstly, aiming at the motion coupling problem, a 3D nonlinear reference guidance model of hypersonic vehicle is constructed based on line of sight (LOS) twist and its rate after their concepts is defined. Secondly, in order to depress the influence of parameter perturbation, a 3D nonlinear sliding mode guidance law adapted to multiconstraint guidance is deduced based on variable structure control theory. Moreover, the stability of this guidance law is proved through theory deduction. Finally, a novel 3D nonlinear pseudo optimal sliding mode guidance law is designed, after its parameters are optimized by introducing pseudo control variable. With the novel guidance law, the motion coupling and parameter perturbation problems can be well avoided and optimal characteristic of guidance parameters is ensured as well. The validity of the guidance law is also validated through simulation experiments.