Sei Zhen Khong

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A generalization of Vinnicombe’s ν-gap metric and corresponding robust feedback stability results are proposed for a class of linear time-varying (LTV) systems in “Robust stability analysis of time-varying linear systems,” SIAM J. Control and Optimization, Vol. 51, pp. 353-379, 2013. An error in the analysis presented therein leads to an omission in the(More)
This paper adapts the DIRECT method with a modified termination criterion for global extremum seeking control of multivariable dynamical plants — DIRECT is a sampling type global optimisation method for Lipschitz-continuous functions defined over compact multidimensional domains. Finite-time semi-global practical convergence is established based on a(More)
A unified framework based on discrete-time gradient-based extremum seeking control is proposed to localise an extremum of an unknown scalar field distribution using a group of equipped with sensors. The controller utilises estimates of gradients of the field from local dithering sensor measurements collected by the mobile agents. It is assumed that(More)
Closed-loop positivity of feedback interconnections of positive monotone nonlinear systems is investigated. It is shown that an instantaneous gain condition on the open-loop systems which implies feedback well-posedness also guarantees feedback positivity. Furthermore, the notion of integral linear constraints (ILC) is utilised as a tool to characterise(More)