GAIN MARGINS AND ROOT LOCUS ASYMPTOTIC-BEHAVIOR IN MULTIVARIABLE DESIGN .2. CRITICAL APPRAISAL OF FREQUENCY-RESPONSE METHODS FROM A ROOT LOCUS POINT OF VIEW

The inverse Nyquist array (INA) and characteristic locus (CL) techniques are considered here. It is shown that attempts to achieve diagonal dominance, a feature necessary for the application of the INA, may on certain occasions lead to infinite zeros of higher order and thus may severely curtail the...