Old spec 3.5 example, Hurwitz shortcut for a third order system (ENGR5001) - Revisica

Old spec 3.5 example, Hurwitz shortcut for a third order systemTutorialOld spec ENGR202Third6 min

ENGR202 (old spec) Control 3.5 Hurwitz Stability Criterion, Hurwitz shortcut example (slides 7-8)

Use the Hurwitz criterion, and its shortcut, to determine the stability of a system with characteristic equation $3s^3 + 3s^2 + 9s + 6 = 0$

Formulas you may need

Hurwitz criterion; shortcut: it is enough that either $\Delta_1, \Delta_3, \Delta_5, \dots > 0$ or $\Delta_2, \Delta_4, \dots > 0$ (with all coefficients positive) (learn this)
Third order: stable if all coefficients are positive and $a_1a_2 > a_0a_3$ (learn this)

Delta_1 =

Delta_2 =

Delta_3 =

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