Title :
Topological theory of 0/0 ambiguities in robust control
Author :
Jonckheere, Edmond A. ; Ke, Nainn-Ping
Author_Institution :
Dept. of Electr. Eng. Syst., Univ. of Southern California, Los Angeles, CA, USA
Abstract :
Allowing some uncertain parameters in the numerator and denominator polynomials of the loop function of a feedback system can result in 0/0 ambiguities at some uncertain points. This in turn could create discrepancies between the stability margins computed from the “value set” approach and the “Horowitz template” approach. In addition, in case of some “essential” ambiguities, the singularity set of the Nyquist map-crucially related to continuity of the margins-is structurally unstable and nearly impossible to compute
Keywords :
Nyquist diagrams; feedback; polynomials; robust control; stability criteria; topology; uncertain systems; 0/0 ambiguities; Horowitz template; Nyquist map; denominator polynomial; essential ambiguities; feedback system; loop function; margin continuity; numerator polynomial; robust control; singularity set; stability margins; topological theory; uncertain parameters; value set; Algebra; Feedback loop; Frequency; Polynomials; Robust control; Robustness; Stability; Transfer functions;
Conference_Titel :
Decision and Control, 1997., Proceedings of the 36th IEEE Conference on
Conference_Location :
San Diego, CA
Print_ISBN :
0-7803-4187-2
DOI :
10.1109/CDC.1997.649545
