How can the Poles of the Root Locus be negative?

1. Can K be negative in root locus?
2. What are poles in root locus?
3. How do you know if a root locus is unstable?
4. What are the rules of root locus?

Can K be negative in root locus?

The root locus is a plot of the locations in the s-plane of all n closed-loop poles as K varies from 0 to positive or negative infinity.

What are poles in root locus?

Locus on Real Axis

The root locus exists on real axis to left of an odd number of poles and zeros of open loop transfer function, G(s)H(s), that are on the real axis. These real pole and zero locations are highlighted on diagram, along with the portion of the locus that exists on the real axis.

How do you know if a root locus is unstable?

The root locus procedure should produce a graph of where the poles of the system are for all values of gain K. When any or all of the roots of D are in the unstable region, the system is unstable. When any of the roots are in the marginally stable region, the system is marginally stable (oscillatory).

What are the rules of root locus?

If a branch on the real axis lies between a pair of poles, the root locus must break away from the real axis somewhere between the poles. Similarly, if a branch on the real axis lies between a pair of zeros, there must be an entry point between that pair of zeros.