Showing papers by "Kumpati S. Narendra published in 1978"
TL;DR: In this paper, the design of stable adaptive controllers using a model reference approach is discussed, and a systematic procedure is developed using the concept of positive realness and is generalized to arbitrarily located coutrol parameters.
Abstract: This paper deals with the design of stable adaptive controllers using a model reference approach. A systematic procedure is developed using the concept of positive realness and is generalized to arbitrarily located coutrol parameters. For plants with n poles and (\geq)(n-2) zeros, the uniform asymptotic stability in the large of the adaptive loop is demonstrated. For plants with (\leq)(n-3) zeros the stability problem is clawed and is stated as a conjecture. Simulation studies of the adaptive control of both stable and unstable plants are included towards the end of the paper.
494 citations
TL;DR: In this paper, the control of an unknown linear time-invariant plant using direct and indirect control is considered and adaptive laws which are very similar are derived for the two cases.
51 citations
01 Jan 1978
TL;DR: In this article, the authors examined the conditions which have to be satisfied for Lyapunov's method to be successfully applied to adaptive observers and controllers and also to demonstrate that they are entirely equivalent.
Abstract: : The aim of this brief paper is to examine the conditions which have to be satisfied for the two approaches to be successfully applied to adaptive observers and controllers and also to demonstrate that they are entirely equivalent. Using a typical error model it is shown that hyperstability and asymptotic hyperstability are achieved under exactly the same conditions as stability and asymptotic stability in the sense of Lyapunov. In those cases where the adaptive control problem remains unresolved, the difficulties encountered using Lyapunov's method are shown to have their counterparts in hyperstability theory as well.
2 citations