Corrigendum to “Circle criterion based H_∞ observer design for Lipschitz and monotonic nonlinear systems—Enhanced LMI conditions and constructive discussions” [Automatica 85 (2017) 412–425, (S0005109817304168), (10.1016/j.automatica.2017.07.067)]

The objective of this Corrigendum is to update Section 3 in Zemouche et al. (2017) to correct a mistake. Indeed, it is not true that we can prove Theorem 5 by only exploiting inequalities (34)–(35) in Zemouche et al. (2017). A correct version of Theorem 5 can be obtained with: [Formula presented]a slight modification of the proposed observer structure (Eq.(27) in Zemouche et al., 2017) and [Formula presented]the addition to the right-hand side of Eq.(31) of a term that was inadvertently left out. Specifically, we now set [Formula presented]in (27d) and correct (31) by adding the term [Formula presented]to its right-hand side. Given that [Formula presented] and [Formula presented]as defined in (27c) in Zemouche et al. (2017), this term comes from the computation of [Formula presented] which was to be [Formula presented]instead of [Formula presented]as it was considered in Zemouche et al. (2017). Then, (31) is obtained with the additional term (1) in its right-hand side by substituting (2) in [Formula presented]and by developing [Formula presented]as in Zemouche et al. (2017, Eq.(30)) with [Formula presented] Hence, by adding the missed term, we correct inequality (33) in Zemouche et al. (2017) by adding the following term to its left-hand side: [Formula presented]where [Formula presented] Finally, by applying the Young inequality on (3) as for the other terms, we obtain the following correct LMI condition, which replaces the original LMI (37): [Formula presented] [Formula presented] [Formula presented] [Formula presented] [Formula presented] [Formula presented] [Formula presented] [Formula presented] [Formula presented] [Formula presented] [Formula presented] [Formula presented] [Formula presented] [Formula presented] The correction affects equation (47) in Zemouche et al. (2017), which should be replaced by the following one: [Formula presented] The rest of the paper is not affected by the wrong version of LMI (37) in Zemouche et al. (2017). The application to vehicle slip angle estimation in Section 6 remains valid for [Formula presented] with the same observer parameters [Formula presented]and [Formula presented] and [Formula presented]given in (60), (62), and (63). The figures are almost identical and undistinguishable from those in Zemouche et al. (2017).