Showing papers by "John B. Moore published in 1980"
01 Dec 1980
TL;DR: It is shown that whether or not there are decentralized fixed modes in the open-loop system, periodically varying feedback gains at all but one of the control stations permit the remaining control station to observe and control the system given knowledge of theControl laws implemented at the other control stations.
Abstract: Decentralized control schemes are considered for time-invariant, finite dimensional, linear systems with known state equations. It is assumed that the systems are reachable and observable at a fictitious centralized control station, and that there is strong connectivity between the decentralized control stations via the system where necessary. It is shown that whether or not there are decentralized fixed modes in the open-loop system, periodically varying feedback gains at all but one of the control stations permit the remaining control station to observe and control the system given knowledge of the control laws implemented at the other control stations. Certain time-invariant systems which cannot be stabilized by decentralized time-invariant controllers, namely those with unstable decentralized fixed modes, can thus be stabilized by decentralized time-varying controllers.
224 citations
TL;DR: In this paper, an extended Kalman filter is used for coordinate estimation of a stationary object using bearing measurements taken from a moving platform, and a bound on the Lyapunov function decay rate is given to assist in the design of the modified nonlinearities and in the selection of an appropriate coordinate basis.
Abstract: Extended Kalman filters are here modified for coordinate estimation of a stationary object using bearing measurements taken from a moving platform. The modifications improve significantly the coordinate estimation on the initial period of data collection when otherwise the performance is far from optimal. The modifications are to the nonlinearities and could, in some instances, be implemented by the introduction of a time decreasing amplitude dither signal in the extended Kalman filter prior to the output nonlinearity. A bound on a Lyapunov function decay rate is also given which assists in the design of the modified nonlinearities and in the selection of an appropriate coordinate basis to be used in the extended Kalman filter.
79 citations
TL;DR: In this article, earlier results for feedback stabilization of linear systems and for Kalman filters and regulators are generalized, with proofs being in fact more direct than those explored earlier, and they are shown to be correct.
Abstract: When stabilizing linear discrete-time finite dimensional systems in control and estimation either optimally or suboptimally, technical difficulties arise in the conventional stability theories for coping with state transition matrices which are permitted to be singular or with eigenvalues arbitrarily small. In overcoming these difficulties, earlier results for feedback stabilization of linear systems and for Kalman filters and regulators are generalized in this paper, with proofs being in fact more direct than those explored earlier.
67 citations
TL;DR: Novel schemes emerge from the theory which, in the cases studied to date and reported here, converge much more rapidly than their nearest rivals amongst the class of known simple schemes.
17 citations
TL;DR: Recursion prediction error identification schemes are studied which incorporate Kalman gain calculations to ensure exponential stability of the predictor and related recursions and the resulting algorithms are attractive for a wide range of applications.
10 citations
01 Dec 1980
TL;DR: In this paper, the convergence theory of martingale convergence is applied to N decomposed terms consisting of the parameter and state estimation errors, guiding the selection of weighting coefficients in a weighted least squares approach.
Abstract: Dual problems of N-step-ahead prediction and control of plants with a series N delay are studied for the case when there are parameter uncertainties in the signal generating system. In particular, novel variations of existing schemes are proposed with the variations introduced to guarantee global convergence. The convergence theory, which applies martingale convergence results to N decomposed terms consisting of the parameter and state estimation errors, guides the selection of weighting coefficients in a weighted least squares approach. There are thus attractions over competitive schemes involving a bank of N interleaved parameter udpate recursions with their additional memory requirements.
4 citations