ABSTRACT
This chapter presents the main characteristics and different types of adaptive control. Adaptive control algorithms are a suitable method to ensure reliable operation of controllers under changing process conditions. Adaptive control schemes can be roughly categorized into open- and closed-loop techniques. Most auto-tuning methods rely on simple experiments on the unknown processes, and can be used either in open-loop or in closed-loop configuration. In contrast to open loop adaptive schemes, in closed loop adaptive techniques outputs of interest are measured directly and used to adapt the controllers continuously. To keep a desired control performance the controller parameters can be adjusted in such a way, that the behavior of the controlled system matches the behavior of a given reference system. This approach is known as model reference adaptive control (MRAC). The dual controller provides a trade-off between excitation of the unknown process for good estimation of the uncertain model parameters and performance of the overall control system.
