Showing papers by "Kumpati S. Narendra published in 1987"
TL;DR: In this paper, a new adaptive law motivated by the work of Loannou and Kokotovic (1983) is proposed for the robust adaptive control of plants with unknown parameters.
Abstract: A new adaptive law motivated by the work of loannou and Kokotovic (1983) is proposed for the robust adaptive control of plants with unknown parameters. In this adaptive law the output error plays a dual role in the adjustment of the control parameter vector. The advantages of using the adaptive law over others proposed in the literature are discussed. In the ideal case the adaptive system has bounded solutions; in addition, the origin of the error equations is exponentially stable when the reference input is persistently exciting and has a sufficiently large amplitude. The adaptive system is also shown to be robust under bounded external disturbances. Finally, it is shown that, by suitably modifying the adaptive law, the overall system can be made robust in the presence of a class of unmodeled dynamics of the plant. Simulation results are presented throughout the paper to complement the theoretical developments.
775 citations
TL;DR: In this article, the authors provide a general framework for the discussion of persistent excitation and collect results in the area, which are scattered throughout the adaptive literature, and present some new results related to the uniform asymptotic stability and robustness of adaptive systems and the relation of PE to the stability properties of a class of non-linear systems.
Abstract: The importance of the concept of persistent excitation (PE) in adaptive identification and control has been recognized for some time. Recently it has become evident that it also plays a central role in many questions related to the robustness of adaptive systems. There is every reason to believe that arguments involving this concept will continue to feature prominently in the analysis of most of the important problems of adaptive control. Hence there is a real need for a deeper understanding of the concept. The paper is written with three objectives. The first, which is tutorial in nature, is to provide a general framework for the discussion of persistent excitation and to collect results in the area, which are scattered throughout the adaptive literature. The second objective is to present some new results related to the uniform asymptotic stability (u.a.s.) and robustness of adaptive systems and the relation of PE to the stability properties of a class of non-linear systems. The final objective is to di...
299 citations
01 Dec 1987
TL;DR: A model of a nonstationary automaton environment, with response characteristics dynamically related to the probabilities of the actions performed on it, is proposed and parameters of the proposed model can be chosen to predict transient behavior.
Abstract: In a data communication network the message traffic has peak and slack periods and the network topology may change. When the learning approach is applied to routing, a learning automation is situation at each node in the network. Each automation selects the routing choices at its node and modifies its strategy according to network conditions. A model of a nonstationary automaton environment, with response characteristics dynamically related to the probabilities of the actions performed on it, is proposed. The limiting behavior of the model is identical to that of the earlier models. Simulation studies of automata operating in simple queuing networks reinforce the analytical results and show that the parameters of the proposed model can be chosen to predict transient behavior.
51 citations
TL;DR: In this article, the problem of adaptively controlling a linear time-invariant plant with unknown parameters based on a reduced order model was considered and it is shown that the above methods can be extended to the adaptive control using reduced order models as well.
4 citations