MESA Lab welcomes Visiting Professor Norelys Aguila Camacho from Universidad Tecnológica Metropolitana Chile
Dr. Prof. Norelys Aguila (email@example.com) our short term visiting professor delivered a seminar on Monday Jan. 16th from 5-6:30pm on "Fractional Order Adaptive Control: the switched order approach". The talk flyer is here. The recorded Youtube video link is available upon rerequest to Prof. Chen at "firstname.lastname@example.org".
ABSTRACT: While controlling a real process, the designer rarely knows its parameters accurately. The characteristics of the process can change with time due to a variety of factors. There may also be unforeseen changes in the statistics of the external inputs and disturbances that may be considered as change in the environment in which the system operates. The tools of conventional control theory, even when used efficiently, may be inadequate to achieve satisfactory performance in the entire range over which the characteristics of the system may vary.
In 1957, Drenick and Shahbender introduced the term adaptive system in control theory to represent control systems that monitor their own performance and adjust their parameters in the direction of better performance. A great deal of work and effort was made along the years to propose different kind of stable adaptive control strategies, but due to their nonlinear nature, a common framework for stability analysis was lacking, until the error model approach appeared.
In early 2000s, fractional operators were introduced in adaptive control, and subsequently a series of generalizations of adaptive schemes were made to the fractional order case. Different advantages of fractional adaptive controllers were reported, such as better management of noise, improvements in transient responses, better behavior in the presence of disturbances, among other. Still, the lack of analytical tools to generalize error model approach to fractional cases was a problem, until some results appeared around 2015 and they were partially solved.
Still, the use of fractional adaptive schemes and classic integer order adaptive schemes usually presented a trade-off among system speed of response and control energy used. This problem has led to a new approach, currently under investigation, regarding the use of switched fractional order adaptive schemes, such as the above mentioned trade-off can be improved.
This talk aims to make a summary of the evolution of adaptive control and ending up presenting the motivation to research about switched order adaptive controllers, as well as the more recent results obtained in that line.
Last creted and updated by Prof. YangQuan Chen 1/20/2023.