Robust modal vibration suppression of a flexible rotor

This study deals with active robust modal vibration control of rotor systems supported by magnetic bearings. The inherent divergent rigid body modes are suppressed by using a dual-level control approach. Finite element method is applied to formulate the rotor model. The Timoshenko beam theory, including the effects of shearing deformations and rotary inertia, is considered in this work. Because practical control systems are often limited by its sensing, hardware, and computation speed capabilities, the reduced order approach is often used for a control system design. This study applies the independent modal space control (IMSC) approach to extract the accurate lower modes from the complex rotor systems with the gyroscopic effect considered. In practice, it is extremely difficult to model the complete dynamic characteristics of a rotor system. The model may contain unmodelled dynamics and parameter changes, which can be viewed as uncertainties of a system. As opposed to the conventional control approach, which requires fixed and accurate system parameters, this study considers robust control approach to design a controller capable of tolerating external disturbance and model uncertainties. It is demonstrated that the proposed approach is effective for vibration suppression when the system is subjected to impulsive or step loading, speed variation, and sudden loss of disk mass.

[1]  W. Gawronski.  Dynamics and control of structures : a modal approach , 1998 .

[2]  L. Meirovitch,et al.  CONTROL OF SELF-ADJOINT DISTRIBUTED-PARAMETER SYSTEMS. , 1980 .

[3]  Leonard Meirovitch,et al.  A comparison of control techniques for large flexible systems , 1983 .

[4]  P. Khargonekar,et al.  State-space solutions to standard H/sub 2/ and H/sub infinity / control problems , 1989 .

[5]  Carl R. Knospe,et al.  Experiments in the control of unbalance response using magnetic bearings , 1995 .

[6]  Z Yu,et al.  Electromagnetic bearing actuator for active vibration control of a flexible rotor , 1998 .

[7]  Yih-Hwang Lin,et al.  Active modal control of a flexible rotor , 2002 .

[8]  M. Balas.  Active control of flexible systems , 1978 .

[9]  Matthew T. Cole,et al.  Multi-State Transient Rotor Vibration Control Using Sampled Harmonics , 2002 .

[10]  Hidekazu Nishimura,et al.  Experimental Study on Active Vibration Control of Structures by means of H∞ Control and H2 Control , 1994 .

[11]  Clifford R. Burrows,et al.  Towards fault-tolerant active control of rotor–magnetic bearing systems , 2004 .

[12]  Patrick Keogh,et al.  Closed-Loop Vibration Control of Flexible Rotors—An Experimental Study , 1993 .

[13]  H. Adelman,et al.  Inclusion of Transverse Shear Deformation in Finite Element Displacement Formulations , 1974 .

[14]  Leonard Meirovitch,et al.  Dynamics And Control Of Structures , 1990 .

[15]  Patrick Keogh,et al.  Optimized Design of Vibration Controllers for Steady and Transient Excitation of Flexible Rotors , 1995 .

[16]  J. Doyle,et al.  Essentials of Robust Control , 1997 .

[17]  Leonard Meirovitch,et al.  Control of Self -Adj oint Distributed-Parameter Systems , 1982 .

[18]  L. Meirovitch,et al.  Modal-Space Control of Distributed Gyroscopic Systems , 1980 .

[19]  Bruce A. Francis,et al.  Feedback Control Theory , 1992 .

[20]  Yih-Hwang Lin,et al.  A new design for independent modal space control of general dynamic systems , 1995 .

[21]  Junji Tani,et al.  Effect of Boundary Condition on the Stability of a Pipe Conveying Fluid. , 1994 .

[22]  P. Khargonekar,et al.  State-space solutions to standard H2 and H∞ control problems , 1988, 1988 American Control Conference.

[23]  G. Zames.  Feedback and optimal sensitivity: Model reference transformations, multiplicative seminorms, and approximate inverses , 1981 .

[24]  H. D. Nelson,et al.  The Dynamics of Rotor-Bearing Systems Using Finite Elements , 1976 .

[25]  K. Glover,et al.  State-space formulae for all stabilizing controllers that satisfy and H ∞ norm bound and relations to risk sensitivity , 1988 .

[26]  Matthew T. Cole,et al.  Control of multifrequency rotor vibration components , 2002 .

[27]  L. Meirovitch,et al.  Modal-Space Control of Large Flexible Spacecraft Possessing Ignorable Coordinates , 1980 .