The root locus method: famous curves, control designs and non-control applications

Famous named curves generated as root loci produce optimum and pseudo-optim um stability designs for realistic systems. Non-minimum-phase control invol ves a principle of topological certainty. A root locus with complex breakpo ints is discussed. Cassini's ovals in Brauer's method of eigenvalue localis ation are illustrated. A problem in dielectric theory, recast into an imagi nary-parameter root locus, is solved via real-parameter theory. Continuatio n, translation and scaling are invoked. It is hoped to impart an appreciati on of the versatility of root-locus-inspired thinking.