Gunter Stein

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—The paper considers a family of linear time-invariant and spatially-invariant (LTSI) systems that are both distributed and localized. The spatial responses of the distributed plant are localized in spatial neighborhoods of each location. The feedback computations are also distributed and the information flow is localized in a spatial neighborhood of each(More)
The preceding argument can be used to justify an infrequent The paper presents a frequency-domain estimator which can control-law redesign strategy. It is envisioned that a identify both a nominal model of a plant as well as a discrete-time estimator will be used to continually update the frequency-domain bounding function on the modeling error(More)
— The paper considers one of the fundamental issues in design and analysis of sampled multidimensional systems-that of uncertainty modeling and robust stability analysis. Methods of structured uncertainty analysis (µ-analysis) are extended towards systems with dynamical and non-causal spatial coordinates. The stability is understood in a broad sense and(More)
A robust gain scheduled controller combined with a parameter estimator produces a robust adaptive controller for a broad class of deterministic but uncertain systems, provided the estimator is efficient in a new, deterministic sense. Abstract-Sufficient conditions are given under which an adaptive control system is robustly stable and achieves a guaranteed(More)
— This work develops control design technology for active shape control of reflective surfaces using large spatially distributed actuator arrays. The potential applications are in astronomy , adaptive optic, beam control, space-based imaging, and other optics and imaging applications. In a very large lightweight active reflector, surface shape (figure)(More)
  • D Orlicki, L Valavani, M Athans, G Stein
parameters to drift from their "desired" values. Abstract Consequently then, the zero tracking error requirement must be suitably relaxed. The ration-It has been found that fixed error dead-zones ale is that no parameter adjustment should take as defined in the existing literature result in place when the output error(s) are due to disturb-serious(More)
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