ABSTRACT
Research in adaptive control has a long history of intense activity involving debates about the precise definition of adaptive control, examples of instabilities, stability and robustness proofs, and applications. Starting in the early 1950s, the design of autopilots for high-performance aircraft motivated an intense research activity in adaptive control.High-performance aircraft undergodrastic changes in their dynamics when they fly from one operating point to another. These changes cannot be handled by constant gain feedback control. A sophisticated controller, such as an adaptive controller, that would be able to learn and accommodate changes in the aircraft dynamics was needed. Model reference adaptive control (MRAC) was suggested by Whitaker et al. [9] to solve the autopilot control problem. The sensitivity method and the MIT rule [18] were used to design the adjustment or adaptive laws for estimating the unknown parameters for the various proposed MRAC schemes.
