- ▪R. Koplon, E.D. Sontag, M. L. J. Hautus, "Observability of linear systems with saturated outputs", Linear Algebra Appl., vol. 205/206, pp. 909–936, 1994. pdf
Abstract
In this paper, we present necessary and sufficient conditions for observability of the class of output-saturated systems. These are linear systems whose output passes through a saturation function before it can be measured.
- ▪R. Schwarzschild, E.D. Sontag, M.L.J. Hautus, "Output-Saturated Systems", In Proc.\ Amer.\ Automatic Control Conf.\ \/, Chicago, June 1992, pp. 2504–2509, 1992.
- ▪M. L. J. Hautus, E.D. Sontag, "New results on pole-shifting for parametrized families of systems", J. Pure Appl. Algebra, vol. 40, no. 3, pp. 229–244, 1986. pdf
Abstract
New results are given on the pole-shifting problem for commutative rings, and these are then applied to conclude that rings of continuous, smooth, or real-analytic functions on a manifold X are PA rings if and only if X is one-dimensional.
- ▪M. L. J. Hautus, E.D. Sontag, "An approach to detectability and observers", In Algebraic and geometric methods in linear systems theory (AMS-NASA-NATO Summer Sem., Harvard Univ., Cambridge, Mass., 1979), pp. 99–135, 1980. pdf
Abstract
This paper proposes an approach to the problem of establishing the existence of observers for deterministic dynamical systems. This approach differs from the standard one based on Luenberger observers in that the observation error is not required to be Markovian given the past input and output data. A general abstract result is given, which special- izes to new results for parametrized families of linear systems, delay systems and other classes of systems. Related problems of feedback control and regulation are also studied.