In a closed loop control system, the most valuable information for predicting system behavior/performane is to know the exact locations of the closed loop poles.  However, you need to be able to calculate a number of things for various reasons - to get the gain to produce particular poles - to estimate response once you have the gain.

• Why learn about root locus calculations?
• You need to be able to determine gain to set poles
• You need to be able to estimate performance once you know where the poles are.
• What should you know to learn about in order to do root locus calculations?
• You need to be clear about the root locus.
• What do you need to know about root locus calculations?
• You need to be able to calculate the gain for a particular point on the root locus.
• You need to be able to estimate performance factors from pole locations.
• Damping Ratio
• Overshoot
• Oscillation Frequency
• How do you use the root locus calculations in design?
• You need to be able to control overshoot, oscillations, etc. when you design a closed loop system.  You can often estimate those factors from pole position on a root locus.
• Problems
• Additional Information
• Click here for a set of links to various root locus calculators.

        Any lab problem that uses proportional control - or any PID controller - can be analyzed using root locus techniques.