Advances in adaptive control theory: gradient- and derivative-free approaches

Kalman filtering;Adaptive control;Derivative-free approaches;Modification terms

Yucelen, Tansel ; Aerospace Engineering

University:Georgia Institute of Technology

Department:Aerospace Engineering

关键词: Kalman filtering;    Adaptive control;    Derivative-free approaches;    Modification terms;   

Others  :  https://smartech.gatech.edu/bitstream/1853/43731/1/yucelen_tansel_201205_phd.pdf

美国|英语

来源: SMARTech Repository

【 摘 要 】

In this dissertation, we present new approaches to improve standard designs in adaptive control theory, and novel adaptive control architectures.We first present a novel Kalman filter based approach for approximately enforcing a linear constraint in standard adaptive control design. One application is that this leads to alternative forms for well known modification terms such as e-modification. In addition, it leads to smaller tracking errors without incurring significant oscillations in the system response and without requiring high modification gain. We derive alternative forms of e- and adaptive loop recovery (ALR-) modifications. Next, we show how to use Kalman filter optimization to derive a novel adaptation law. This results in an optimization-based time-varying adaptation gain that reduces the need for adaptation gain tuning.A second major contribution of this dissertation is the development of a novel derivative-free, delayed weight update law for adaptive control. The assumption of constant unknown ideal weights is relaxed to the existence of time-varying weights, such that fast and possibly discontinuous variation in weights are allowed. This approach is particularly advantageous for applications to systems that can undergo a sudden change in dynamics, such as might be due to reconfiguration, deployment of a payload, docking, or structural damage, and for rejection of external disturbance processes.As a third and final contribution, we develop a novel approach for extending all the methods developed in this dissertation to the case of output feedback. The approach is developed only for the case of derivative-free adaptive control, and the extension of the other approaches developed previously for the state feedback case to output feedback is left as a future research topic.The proposed approaches of this dissertation are illustrated in both simulation and flight test.