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design of bearings for rotor systems based on stabilityDesign of rotor systems incorporating stable behavior is of great importance to manufacturers of high speed centrifugal machinery since destabilizing mechanisms (from bearings, seals, aerodynamic cross coupling, noncolocation effects from magnetic bearings, etc.) increase with machine efficiency and power density. A new method of designing bearing parameters (stiffness and damping coefficients or coefficients of the controller transfer function) is proposed, based on a numerical search in the parameter space. The feedback control law is based on a decentralized low order controller structure, and the various design requirements are specified as constraints in the specification and parameter spaces. An algorithm is proposed for solving the problem as a sequence of constrained 'minimax' problems, with more and more eigenvalues into an acceptable region in the complex plane. The algorithm uses the method of feasible directions to solve the nonlinear constrained minimization problem at each stage. This methodology emphasizes the designer's interaction with the algorithm to generate acceptable designs by relaxing various constraints and changing initial guesses interactively. A design oriented user interface is proposed to facilitate the interaction.
Document ID
Document Type
Conference Paper
Dhar, D.
(Virginia Univ. Charlottesville, VA, United States)
Barrett, L. E.
(Virginia Univ. Charlottesville, VA, United States)
Knospe, C. R.
(Virginia Univ. Charlottesville, VA, United States)
Date Acquired
September 6, 2013
Publication Date
May 1, 1992
Publication Information
Publication: NASA. Langley Research Center, International Symposium on Magnetic Suspension Technology, Part 2
Subject Category
Distribution Limits
Work of the US Gov. Public Use Permitted.
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