Numerically Efficient Robustness Analysis of Trajectory Tracking for Nonlinear Systems

A numerical algorithm for computing necessary conditions for performance specifications is developed for nonlinear uncertain systems following a prescribed trajectory. This algorithm provides a computational efficient means of evaluating the performance of a nonlinear system in the presence of noise, real parametric uncertainty, and unmodeled dynamics. The algorithm is similar in nature and behavior to the power algorithm for the mu lower bound, and does not rely on a descent method. The algorithm is applied to two flight control examples.