Application of matrix singular value properties for evaluating gain and phase margins of multiloop systemsA stability margin evaluation method in terms of simultaneous gain and phase changes in all loops of a multiloop system is presented. A universal gain-phase margin evaluation diagram is constructed by generalizing an existing method using matrix singular value properties. Using this diagram and computing the minimum singular value of the system return difference matrix over the operating frequency range, regions of guaranteed stability margins can be obtained. Singular values are computed for a wing flutter suppression and a drone lateral attitude control problem. The numerical results indicate that this method predicts quite conservative stability margins. In the second example if the eigenvalue magnitude is used instead of the singular value, as a measure of nearness to singularity, more realistic stability margins are obtained. However, this relaxed measure generally cannot guarantee global stability.
Document ID
19830031239
Acquisition Source
Legacy CDMS
Document Type
Conference Proceedings
Authors
Mukhopadhyay, V. (Joint Institute for Advancement of Flight Sciences Hampton, VA, United States)
Newsom, J. R. (NASA Langley Research Center Loads and Aeroelasticity Div., Hampton, VA, United States)