Popli, N; Pequito, S; Kar, S; Aguiar, AP; Ilic, M

AUTOMATICA

ID Authenticus: P-00Q-P0F

DOI: 10.1016/j.automatica.2019.05.036

Abstract: One of the steps in the proof of Theorem 1 in Popli, Pequito, Kar, Aguiar, and Ili¿ (2019) invokes a result from Pequito, Popli, Kar, Ili, and Aguiar (2013) that asserts that a system is selective strong structurally controllable if and only if it can be reduced to a ramp structure (Theorem 1, Pequito et al., 2013). However, there is a gap in the `only if¿ part of the argument, and indeed that part does not hold in general. Consequently, in Popli et al. (2019), the solution to Problem 1 (i.e., to determine the robust minimum cost actuation-sensing-communication) stated in Theorem 3 is generally suboptimal. For certain structural patterns though, the conditions presented are necessary and sufficient, in which case optimality does hold