Structured stability robustness improvement by eigenspace techniques- A hybrid methodology

A new hybrid design technique for improving stability robustness with respect to block-structured perturbations in multivariable linear feedback systems is presented. This new methodology is hybrid in that it uses both constrained optimization techniques for robustness and eigenstructure assignment for performance. This approach allows the designer to treat simultaneous perturbations occurring at different locations in the feedback system without having to compromise between robustness and performance. Performance requirements expressed in terms of closed-loop eigenvalues and right-eigenvectors are directly satisfied by the procedure. The realistic example of the SA365N DOLPHIN helicopter is presented to highlight the merits and some of the concerns in using this methodology.

[1]  J. Doyle,et al.  Minimizing Conservativeness of Robustness Singular Values , 1984 .

[2]  M. Barrett.  Conservatism with robustness tests for linear feedback control systems , 1980, 1980 19th IEEE Conference on Decision and Control including the Symposium on Adaptive Processes.

[3]  David F. Shanno,et al.  Algorithm 500: Minimization of Unconstrained Multivariate Functions [E4] , 1976, TOMS.

[4]  M. Athans,et al.  Robustness results in linear-quadratic Gaussian based multivariable control designs , 1981 .

[5]  J. Kantor.  The Analysis of Robust Stability and Performance in Multivariable Feedback Systems using M-Matrices , 1985, 1985 American Control Conference.

[6]  Sanjay Garg,et al.  Integrated Flight/Propulsion Control System Design Based on a Centralized Approach , 1989 .

[7]  E.Y. Shapiro,et al.  Eigenstructure Assignment for Linear Systems , 1983, IEEE Transactions on Aerospace and Electronic Systems.

[8]  Michael Safonov.  Exact calculation of the multivariable structured-singular-value stability margin , 1984, The 23rd IEEE Conference on Decision and Control.

[9]  G. Stein,et al.  Multivariable feedback design: Concepts for a classical/modern synthesis , 1981 .

[10]  J. Cruz,et al.  Robustness analysis using singular value sensitivities , 1981, 1981 20th IEEE Conference on Decision and Control including the Symposium on Adaptive Processes.

[11]  John C. Doyle.  Analysis of Feedback Systems with Structured Uncertainty , 1982 .

[12]  V. Mukhopadhyay,et al.  The use of singular value gradients and optimization techniques to design robust controllers for multiloop systems , 1983 .

[13]  G. Stein,et al.  The LQG/LTR procedure for multivariable feedback control design , 1987 .

[14]  I. Postlethwaite,et al.  The generalized Nyquist stability criterion and multivariable root loci , 1977 .

[15]  B. Levy,et al.  Robustness tests utilizing the structure of modelling error , 1981, 1981 20th IEEE Conference on Decision and Control including the Symposium on Adaptive Processes.

[16]  G. Stein,et al.  Performance and robustness analysis for structured uncertainty , 1982, 1982 21st IEEE Conference on Decision and Control.

[17]  M. Safonov.  Stability margins of diagonally perturbed multivariable feedback systems , 1982 .