Robustness of an optimized fuzzy logic controller to plant variations

The application of a stochastic optimizer to the problem of the control of a highly flexible space structure, and its robustness, is examined. The optimized fuzzy logic controller is used to perform a certain maneuver. A model of the flexible space structure was developed in a rigid multi-body dynamics software package called Odessa, and this model was used as a basis for deriving a number of other simulation models that have physical properties deviating from those of the ideal model. These models are used to check robustness of the optimized fuzzy logic controller with respect to various degrees of physical property deviation of the structure. Model variations were classified into a number of categories. Results of the simulations are presented in a convenient format to make comparison of the controller performance under various system parameter deviations easier. These simulations show the fuzzy logic controller to be remarkably robust.