A criterion for estimating robust time delays for closed-loop stability

A formula for estimating robust time delays for closed-loop stability is presented. Continuous, single-input-single-output, linear, time-invariant systems represented by their rational transfer functions, which are not necessarily stable, are considered. The proposed formula is derived using the symmetric Rouche form. An illustrative example is included, and some closing remarks concerning the merits of the formula are made.<
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