  A straight forward application of feedback linearization to the missile
autopilot design for acceleration control may be limited due to the nonminimum
characteristics and the model uncertainties. As a remedy, this paper presents a
cascade structure of an acceleration controller based on approximate feedback
linearization methodology with a time-delay adaptation scheme. The inner loop
controller is constructed by applying feedback linearization to the approximate
system which is a minimum phase system and provides the desired acceleration
signal caused by the angle-of-attack. This controller is augmented by the
time-delay adaptive law and the outer loop PI (proportional-integral)
controller in order to adaptively compensate for feedback linearization error
because of model uncertainty and in order to track the desired acceleration
signal. The performance of the proposed method is examined through numerical
simulations. Moreover, the proposed controller is tested by using an intercept
scenario in 6DOF nonlinear simulations.
