A nonlinear adaptive variable structure control method is proposed in the presence of model nonlinearity and
parameters uncertainty for high maneuvers flight. The adaptive sliding mode control law is obtained recursively via an
appropriate choice of Lyapunov function based on backstepping procedure. With fixed parameters optimization done by
using a chaotic particle swarm optimization algorithm of adaptive parameter strategy, good system performance is achieved.
To prevent the singularity of the high-frequency gain matrix during parameter adaptation, a SDU decomposition of matrix is
found, which is useful to get non-singular control law. Simulation results show the effectiveness of the control algorithm.