Synthesis of adaptive control systems using the concept of parametric negative feedback (Q1914139)

The synthesis of the algorithms for controller parameter adaptation is addressed in a general framework, able to cover the case of nonlinear and time-varying systems. Consequently, this approach allows circumventing the need for the quasi steadiness hypothesis with respect to the parameters of the controlled plant. The key issue consists in the use of the parametric negative feedback, which is exploited by three different techniques for controller parameter adaptation: the direct estimation of the parameter deviation from the reference values, a modified gradient method, and the second Lyapunov method. The adaptation algorithm may contain proportional, integral, differential, relay, and exponential components; the efficiency of the adaptation loop depends on the selected combination of these components.