Laboratory for Control, Learning, and Systems Biology

switched systems

2019
  1. M. Sadeghi, M.A. Al-Radhawi, M. Margaliot, E.D. Sontag, "No switching policy is optimal for a positive linear system with a bottleneck entrance", IEEE Control Systems Letters, vol. 3, pp. 889-894, 2019. pdf
    (Also in Proc. 2019 IEEE Conf. Decision and Control.)
    Abstract

    We consider a nonlinear SISO system that is a cascade of a scalar "bottleneck entrance" with a stable positive linear system. In response to any periodic inflow, all solutions converge to a unique periodic solution with the same period. We study the problem of maximizing the averaged throughput via controlled switching. We compare two strategies: 1) switching between a high and low value, and 2  using a constant inflow equal to the prescribed mean value. We show that no possible switching policy can outperform a constant inflow rate, though it can approach it asymptotically. We describe several potential applications of this problem in traffic systems, ribosome flow models, and scheduling at security checks.

2009
  1. D. Angeli, P. de Leenheer, E.D. Sontag, "Chemical networks with inflows and outflows: A positive linear differential inclusions approach", Biotechnology Progress, vol. 25, pp. 632-642, 2009. pdf
    Abstract

    Certain mass-action kinetics models of biochemical reaction networks, although described by nonlinear differential equations, may be partially viewed as state-dependent linear time-varying systems, which in turn may be modeled by convex compact valued positive linear differential inclusions. A result is provided on asymptotic stability of such inclusions, and applied to biochemical reaction networks with inflows and outflows. Included is also a characterization of exponential stability of general homogeneous switched systems