Root Locus Essay

The main purposes in conducting this assignment are:
• To able to carry out analysis into complex engineering problem making use of systematic approach to provide valid conclusion.
• To be able to apply appropriate techniques, resources and modern engineering and IT tools (Matlab) towards the assigned question.
• To learn about a control system analysis and design tool called the root locus.
• To highlight the tight link between the theory and applications and the design process.

INTRODUCTION:

In an engineered system we may normally have one or more design parameters, adjustments, or user settings. It is essential to determine if any of these will make the system unstable. This is generally undesirable and possibly hazardous. For example, think of a washing machine that vibrates so much that it ‘walks’ across a floor, or a high speed aircraft that fails due to resonant vibrations. Root-locus plots are used to plot the system roots over the range of a variable to determine if the system will become unstable, or oscillate.

The root locus is a widely used tool for design of closed loop systems, and it has the desirable quality of being a good design tool for continuous time systems (where you work in the s-plane) and for sampled (computer controlled) systems (where you work in the z-plane). This is a technique used as a stability criterion in the field of control systems developed by Walter R. Evans which can determine the stability of the system. The root locus plots the poles of the closed loop transfer function as a function of a gain