ABSTRACT
This chapter discusses the techniques for designing controllers for feedback control systems. The various controller design techniques include the root locus (RL) technique, full state feedback design, and frequency response design. The chapter focuses on the design of control systems using the RL technique. The structure of the feedback control system for the RL design includes the process to be controlled, a sensor that measures the output, and a cascade controller. The RL constitutes a graph of the closed-loop root locations, that is, the roots of the closed-loop characteristic polynomial, with variation in the controller gain. All RL plots share common properties, which are referred as the root locus rules. The analytic RL conditions refer to the conditions that are satisfied by the points that lie on the RL plot and are the poles of the resulting closed-loop characteristic polynomial.
