Improved Transient Response in Adaptive Control Using Projection Algorithms and Closed Loop Reference Models

This paper explores the properties of adaptive systems with closed–loop reference models. Historically, reference models in adaptive systems run open–loop in parallel with the plant and controller, using no information from the plant or controller to alter the trajectory of the reference system. Closed–loop reference models on the other hand use information from the plant to alter the reference trajectory. Using the extra design freedom available in closed–loop reference models, we design adaptive controllers that are (a) stable, and (b) have improved transient properties. Numerical studies that complement theoretical derivations are also reported.