Qualitative models for adaptive critic neurocontrol

We demonstrate the use of qualitative models in the dual heuristic programming (DHP) method of training neurocontrollers. Two fuzzy approaches to developing qualitative models are explored: a priori application of problem specific knowledge, and estimation of a first order TSK fuzzy model. These approaches are demonstrated respectively on the cart-pole system and a nonlinear multiple-input-multiple-output plant proposed by Narendra. In both cases we find that a simplified model based on a Fuzzy framework enables better performance to be obtained as compared to use of non-fuzzy models of equivalent complexity. In both cases we use models that, while poor as one-step predictors, achieve effectiveness in the DHP training context equivalent to that of exact analytic models