@article{b03d91af93394e7b845dd1afae414019,
title = "On Modifying Model Reference Adaptive Control Schemes for Performance Improvement",
abstract = "The idea of improving the transient behavior in model reference adaptive control by using the estimation error to modify the underlying controller structure has recently attracted some attention in the literature. In this note, we show that the modifications proposed so far can in fact all be derived as a linear feedback from the tracking error. Consequently, the improved performance obtained with such a scheme is solely due to a nonadaptive high gain feedback.",
author = "Aniruddha Datta and Ho, {Ming Tzu}",
note = "Funding Information: Recently there has been some interest in improving the zero-statel performance of model reference adaptive control (MRAQschemes by modifying the standard model reference control law [I] with the addition of an auxiliary component synthesized from the estimation error [2]-[4]. In this note, we show that the controller modifications in [3], [4] can be implemented as a linear feedback from the tracking error. This implementation is conceptually important because it clearly brings out the fact that the improved performance proven in these and other related papers is due only to a high gain type linear nonadaptive feedback. In addition, it also clarifies why the estimation error feedback originally proposed in [2] had to be augmented with a “swap” term in 131 before any performance improvement could be analytically proven. Once it is realized that it is the tracking error that needs to be fed back, the extension of the result in [3] to Manuscript received November, 1992; revised June, 1993 and September, 1993. This work was supported,by the National Science Foundation under Grant ECS-9210726. The authors are with the Department of Electrical Engineering, Texas A&M University, College Station, TX 77843-31 28 USA. IEEE Log Number 9403942. In this note, the qualifier “zero-state” refers to zero initial conditions.",
year = "1994",
month = sep,
doi = "10.1109/9.317139",
language = "English",
volume = "39",
pages = "1977--1980",
journal = "IEEE Transactions on Automatic Control",
issn = "0018-9286",
publisher = "Institute of Electrical and Electronics Engineers Inc.",
number = "9",
}