Showing papers by "John B. Moore published in 1985"
19 Jun 1985
TL;DR: In this article, the authors develop output reachability characterizations of linear finite dimensional systems, so as to translate excitation properties of system inputs to excitation property of system outputs, states, or associated regression vectors, and suggest modifications to standard adaptive schemes to ensure the required persistence of excitation.
Abstract: This paper develops output reachability characterizations of linear finite dimensional systems, so as to translate excitation properties of system inputs to excitation properties of system outputs, states, or associated regression vectors. Such properties are of fundamental concern for convergence of algorithms involving on-line identification, adaptive state estimation, prediction and control. The case of adaptive control is of particular interest since it is desirable that persistence of excitation of associated regression vectors be maintained in the presence of time-varying feedback controllers. Persistence of excitation guarantees convergence without a priori stability assumptions and ensures robustness properties. The theory of the paper suggests modifications to standard adaptive schemes to ensure the required persistence of excitation.
68 citations
TL;DR: I. FIXED MODES and DECENTRALIZED CONTROL: ELIMINATING DECENTralIZED FIXed MODES with time-Varying CONTROLLers.
Abstract: I. FIXED MODES AND DECENTRALIZED CONTROL . . . A. WHAT ARE FIXED MODES?.. . . . . . . . B. DECENTRALIZED FIXED MODES AN EXAMPLE c. CHARACTERIZATION OF FIXED MODES . . . . II. ELIMINATING DECENTRALIZED FIXED MODES WITH TIME-VARYING CONTROLLERS . . . . . . . A. THE TECHNICAL LEMMAS . . . . . . . . . B. FORMAL RESULTS . . . . . . . . . . . . c. MULTICHANNEL SYSTEMS . . . . . . . . D. AREAS FOR FURTHER STUD; . . . . . . . . REFERENCES . . . . . . . . . . . . . . . . . . . . . 85 . . . . . 85 . . . . . 89 . . . . . 90
14 citations
TL;DR: In this article, the convergence analysis for stochastic adaptive control of linear discrete-time systems is developed for a wide class of control schemes with the property that when there is consistant deterministic plant parameter estimation, closed loop stability is achieved.
11 citations
19 Jun 1985
TL;DR: In this paper, the adaptive control law is integrated with a nominal constant gain controller and furnishes the equivalent of a 180° phase margin at the flutter frequency for an aircraft flying in turbulence.
Abstract: This paper presents an application of adaptive control to flutter suppression for an aircraft flying in turbulence. The adaptive control law is integrated with a nominal constant gain controller and furnishes the equivalent of a 180° phase margin at the flutter frequency. The design approach blends the classical, linear quadratic Gaussian and adaptive synthesis techniques so that each contributes at its point of strength to achieve a robust control law with good performance characteristics. It is shown that the adaptive controller stabilizes the flutter in the face of arbitrary initial parameter estimates, unmodeled stochastic inputs and significant level of spillover dynamics. The results presented in this paper are very encouraging and motivates continuing work in the field.
5 citations
TL;DR: In this article, the adaptive control law is integrated with a nominal constant gain controller and furnishes the equivalent of a 180 0 phase margin at the flutter frequency, which is shown to stabilise flutter in the face of arbitrary initial parameter estimates, unmodeled stochastic inputs and significant level of spillover dynamics.
5 citations
TL;DR: In this article, the authors show that the combination of these two forms of convergence results makes the stability results more robust and potentially of more practical significance, and they also show that combining almost sure and p-th mean convergence is more robust.
4 citations
01 Dec 1985
TL;DR: In this article, the adaptive control theory of the self-tuning-regulator (STR) algorithm is justified by a rigorous global convergence theory, as outlined in the paper.
Abstract: It is only now, after one decade of adaptive control theory development following on from the self-tuning-regulator (STR) algorithms of Astrom and Wittenmark, that the original insights imbedded in its design are justified by a rigorous global convergence theory, as outlined in the paper. The original STR is of current interest from a theoretical point of view because it is the first example of a direct adaptive stochastic control scheme for which the plant noise, when present, is sufficient to achieve the persistence of excitation required for asymptotic optimality. This aspect is featured in the theory of the paper. The theory of the paper also generalizes open-loop extended least squares (recursive maximum likelihood) global convergence theory to the case where state estimates involving a priori noise estimates are employed rather than a posteriori ones as in existing theories.
3 citations
TL;DR: In this paper, the authors show that the combination of these two forms of convergence results makes the stability results more robust and potentially of more practical significance, and they also show that combining almost sure and p-th mean convergence is more robust.