Stability of open loop system

The open loop control system is absolutely stable if all the poles of the open loop transfer function present in left half of 's' plane. Similarly, the closed loop control system is absolutely stable if all the poles of the closed loop transfer function present in the left half of the 's' plane.

1. Why is open loop system more stable?
2. Can an open loop system be unstable?
3. Which is more stable open loop and closed loop?
4. What is loop stability?

Why is open loop system more stable?

As compared to closed loop system an open loop control system is more stable as all its roots are in left half of s plane only, but it less accurate since there is no feedback to measure the output value and compare it with the input value.

Can an open loop system be unstable?

Yes, open-loop systems can be unstable (examples below, there's innumerable ones).

Which is more stable open loop and closed loop?

Closed loop control system is comparatively accurate because the feedback maintains its accuracy. The stability of open loop control system is more, i.e., the output of the open loop system remains constant. Closed loop control system is comparatively less stable.

What is loop stability?

The loop stability is determined by looking at the number of encirclements of the (-1, 0) point on this plot. For a typical analog feedback loop power supply, its open-loop transfer function is typically stable (that is, without RHP).