Design of missile autopilot applying the immersion and invariance algorithm

The difficulties in designing an effective load autopilot for missile arise from highly nonlinear and non-minimum phase plant characteristics from load command to missile load output. In this paper, the method of designing controller relied upon the notion of system immersion and manifold invariance. The construction of the stabilizing control laws resembles the procedure used in nonlinear regulator theory to derive the (invariant) output zeroing manifold and its friend. The method is well suited in situations where we know a stabilizing controller of a nominal reduced order mode, which we would like to robustify with respect to higher order dynamics. This method overcomes these difficulties and the designed autopilot improves system performances.