s-plane (Drag the 'X')
Time-Domain Mode
h(t) vs t
System Stability & Characteristic Mode
Behavior:
Decaying Oscillation
BIBO Stability:
Stable
Time-Domain Formula:
h(t) = e-0.16t cos(4.85t) u(t)
Recall: The pole location p = σ + jω directly determines the characteristic mode. The real part (σ) governs exponential growth/decay, and the imaginary part (ω) governs the oscillation frequency.
What to notice
- Drag the poles in the s-plane to see the time-domain mode change instantly.
- Notice how poles in the Left Half-Plane (LHP) always produce decaying signals (Stable).
- Poles in the Right Half-Plane (RHP) produce growing signals that eventually blow up (Unstable).
- Moving a pole vertically changes the frequency of oscillation without affecting the decay/growth rate.
- Poles exactly on the jω-axis cause pure, sustained oscillations (Marginally stable).
- A pole exactly at the origin (s=0) produces a constant step function (integrator).