Robust Control of the Elastodynamic Vibrations of a Flexible Rotor System With Discontinuous Friction

2011 ◽  
Vol 133 (3) ◽  
Author(s):  
Mansour Karkoub
Keyword(s):  
Dynamic Model ◽  
Design Process ◽  
Nonlinear Models ◽  
Control Design ◽  
Rotor System ◽  
Control Technique ◽  
Flexible Rotor ◽  
Highly Nonlinear ◽  
Modeling Errors ◽  
The Difference

The work presented here deals with the control of a flexible rotor system using the μ-synthesis control technique. This technique allows for the inclusion of modeling errors in the control design process in terms of uncertainty weights. The dynamic model of the rotor system, which includes discontinuous friction, is highly nonlinear and has to be linearized around an operating point in order to use μ-synthesis. The difference between the linear and nonlinear models is characterized in terms of uncertainty weights and included in the control design process. The designed controller is robust to uncertainty in the dynamic model, spillover, actuator uncertainty, and noise. The theoretical findings of the μ-synthesis control design are validated through simulations and the results are presented and discussed here.

Vibration and Control of a Flexible Rotor in Magnetic Bearings Using Hybrid Method and H∞ Control Theory

1997 ◽  
Vol 119 (1) ◽  
pp. 178-185 ◽  
Author(s):  
T. N. Shiau ◽  
G. J. Sheu ◽  
C. D. Yang
Keyword(s):  
Control Theory ◽  
Hybrid Method ◽  
Control Design ◽  
Expansion Method ◽  
Rotor System ◽  
Magnetic Bearings ◽  
Experimental Simulation ◽  
Model Parameters ◽  
Flexible Rotor ◽  
H2 Control

The vibration and active control of a flexible rotor system with magnetic bearings are investigated using Hybrid Method (HM) and H∞ control theory with consideration of gyroscopic effect. The hybrid method, which combines the merits of the finite element method (FEM) and generalized polynomial expansion method (GPEM) is employed to model the flexible rotor system with small order of plant. The mixed sensitivity problem of H∞ control theory is applied to design the control of system vibration with spillover phenomena for the reduced order plant. The H2 control design is also employed for comparison with the H∞ design. The experimental simulation is used to illustrate the effects of control design. It is shown that the H∞ controller design can be very effective to suppress spillover phenomena. In addition, the H∞ control design has robustness to the variation of the model parameters. The application of the hybrid method (HM) together with H∞ control design is highly recommended for vibration control of flexible rotor systems with magnetic bearings.

scholarly journals Vibration and Control of a Flexible Rotor in Magnetic Bearings Using Hybrid Method and H∞ Control Theory

1994 ◽  
Author(s):  
Ting Nung Shiau ◽  
Geeng Jen Sheu ◽  
Clann Dong Yang
Keyword(s):  
Control Theory ◽  
Hybrid Method ◽  
Controller Design ◽  
Control Design ◽  
Expansion Method ◽  
Rotor System ◽  
Magnetic Bearings ◽  
Experimental Simulation ◽  
Flexible Rotor ◽  
H2 Control

The vibration and active control of a flexible rotor system with magnetic bearings is investigated using Hybrid Method (HM) and H∞ control theory with consideration of gyroscopic effect. The hybrid method which combines the merits of finite element method (FEM) and generalized ploynomial expansion method (GPEM) is employed to model the flexible rotor system with small order of plant. The mixed sensitivity problem of H∞ control theory is applied to design the control of system vibration with spillover phenomena for the reduced order plant. The H2 control design is also employed for the comparison to the H∞ design. The experimental simulation is used to illustrate the effects of control design. It is shown that the H∞ controller design can be very effective to suppress spillover phenomena. In addition, HM control design has robustness to the variation of the parameters of the model. The application of hybrid method (HM) together with H∞ control design is highly recommended for the vibration control of flexible rotor system with magnetic bearings.

Research on Dynamic Model of Rotors with Bearing Misalignment

2014 ◽  
Vol 539 ◽  
pp. 3-8 ◽  
Author(s):  
De Xin Ren ◽  
Jie Hong ◽  
Cun Wang
Keyword(s):  
Dynamic Model ◽  
Rotor System ◽  
Flexible Rotor ◽  
Bending Rigidity ◽  
Lagrange Method ◽  
Motion Equations ◽  
Excitation Force ◽  
Aero Engines ◽  
The Relationship ◽  
Mechanics Characteristics

Based on the structural and mechanics analysis of aero-engines rotor system, the dynamic model of the flexible rotor system with multi-supports are presented in order to solve the bearing misalignment problem of rotor system in aero-engines. The motion equations are derived through Lagrange method. The relationship between structural and mechanics characteristics parameters are built up. Finally, the dynamic influence of bearing misalignment on rotor system is divided into three kinds: additional rotor bending rigidity, additional bearing misalignment excitation force and additional imbalance. The equations suggest that additional imbalance excitation force activates the nonlinearity on rotor system and an additional 2× excitation force might appear.

Modelling of Misaligned Rotor Systems in Aero-Engines

2012 ◽  
Author(s):  
Jun Li ◽  
Jie Hong ◽  
Yanhong Ma ◽  
Dayi Zhang
Keyword(s):  
Dynamic Model ◽  
Rotor System ◽  
Flexible Rotor ◽  
Lagrange Equations ◽  
Rotor Systems ◽  
Nonlinear Properties ◽  
Aero Engine ◽  
Series Of Experiments ◽  
Aero Engines ◽  
Good Agreement

Based on the analysis of structural and dynamic characteristics, a dynamic model of flexible rotor system under misalignment and unbalance excitation in aero-engine was developed through Lagrange equations. The model describes the mechanism and influencing factors of nonlinear properties of misaligned rotors. Then some numerical simulations were performed in order to get the vibration response in time and frequency domain. The results suggest that the rotor system and its coupling may behave in a complex and nonlinear way with the excitation of misalignment and unbalance. The response of the system contains 1× and 2× harmonics, and the spectrum signature closely relate to the misalignment magnitude and the distribution of unbalance mass. A series of experiments were also designed to verify the dynamic model. Their characteristics of response are in good agreement.

Perancangan Boneka Edukasi Terinspirasi oleh Pencipta Boneka Si Unyil

2018 ◽  
Vol 1 ◽  
Author(s):  
Azhari Amri
Keyword(s):  
Design Process ◽  
Urban Culture ◽  
Urban Life ◽  
Rural Region ◽  
The Public ◽  
The Creation ◽  
The Difference ◽  
The City ◽  
Simple Materials

Film Unyil puppet comes not just part of the entertainment world that can be enjoyed by people from the side of the story, music, and dialogue. However, there is more value in it which is a manifestation of the creator that can be absorbed into the charge for the benefit of educating the children of Indonesia to the public at large. The Unyil puppet created by the father of Drs. Suyadi is one of the works that are now widely known by the whole people of Indonesia. The process of creating a puppet Unyil done with simple materials and formation of character especially adapted to the realities of the existing rural region. Through this process, this research leads to the design process is fundamentally educational puppet inspired by the creation of Si Unyil puppet. The difference is the inspiring character created in this study is on the characters that exist in urban life, especially the city of Jakarta. Thus the results of this study are the pattern of how to shape the design of products through the creation of the puppet with the approach of urban culture.

scholarly journals Design of Satellite Attitude Control Algorithm Based on the SDRE Method Using Gas Jets and Reaction Wheels

2013 ◽  
Vol 2013 ◽  
pp. 1-8 ◽  
Author(s):  
Luiz C. G. de Souza ◽  
Victor M. R. Arena
Keyword(s):  
Attitude Control ◽  
Control Algorithm ◽  
Controller Design ◽  
Algorithm Design ◽  
Large Angle ◽  
Space Mission ◽  
Control Technique ◽  
Gas Jets ◽  
State Dependent ◽  
Highly Nonlinear

An experimental attitude control algorithm design using prototypes can minimize space mission costs by reducing the number of errors transmitted to the next phase of the project. The Space Mechanics and Control Division (DMC) of INPE is constructing a 3D simulator to supply the conditions for implementing and testing satellite control hardware and software. Satellite large angle maneuver makes the plant highly nonlinear and if the parameters of the system are not well determined, the plant can also present some level of uncertainty. As a result, controller designed by a linear control technique can have its performance and robustness degraded. In this paper the standard LQR linear controller and the SDRE controller associated with an SDRE filter are applied to design a controller for a nonlinear plant. The plant is similar to the DMC 3D satellite simulator where the unstructured uncertainties of the system are represented by process and measurements noise. In the sequel the State-Dependent Riccati Equation (SDRE) method is used to design and test an attitude control algorithm based on gas jets and reaction wheel torques to perform large angle maneuver in three axes. The SDRE controller design takes into account the effects of the plant nonlinearities and system noise which represents uncertainty. The SDRE controller performance and robustness are tested during the transition phase from angular velocity reductions to normal mode of operation with stringent pointing accuracy using a switching control algorithm based on minimum system energy. This work serves to validate the numerical simulator model and to verify the functionality of the control algorithm designed by the SDRE method.

A Multi-Cylinder HCCI Engine Model for Control

2004 ◽  
Author(s):  
Jason S. Souder ◽  
Parag Mehresh ◽  
J. Karl Hedrick ◽  
Robert W. Dibble
Keyword(s):  
Design Process ◽  
Control Design ◽  
The Other ◽  
Variable Valve Timing ◽  
Valve Timing ◽  
Coupling Effects ◽  
Hcci Engine ◽  
Engine Model ◽  
Hcci Engines ◽  
Variable Valve

Homogeneous charge compression ignition (HCCI) engines are a promising engine technology due to their low emissions and high efficiencies. Controlling the combustion timing is one of the significant challenges to practical HCCI engine implementations. In a spark-ignited engine, the combustion timing is controlled by the spark timing. In a Diesel engine, the timing of the direct fuel injection controls the combustion timing. HCCI engines lack such direct in-cylinder mechanisms. Many actuation methods for affecting the combustion timing have been proposed. These include intake air heating, variable valve timing, variable compression ratios, and exhaust throttling. On a multi-cylinder engine, the combustion timing may have to be adjusted on each cylinder independently. However, the cylinders are coupled through the intake and exhaust manifolds. For some of the proposed actuation methods, affecting the combustion timing on one cylinder influences the combustion timing of the other cylinders. In order to implement one of these actuation methods on a multi-cylinder engine, the engine controller must account for the cylinder-to-cylinder coupling effects. A multi-cylinder HCCI engine model for use in the control design process is presented. The model is comprehensive enough to capture the cylinder-to-cylinder coupling effects, yet simple enough for the rapid simulations required by the control design process. Although the model could be used for controller synthesis, the model is most useful as a starting point for generating a reduced-order model, or as a plant model for evaluating potential controllers. Specifically, the model includes the dynamics for affecting the combustion timing through exhaust throttling. The model is readily applicable to many of the other actuation methods, such as variable valve timing. Experimental results validating the model are also presented.

A Dynamic Model of III-V Ternary Semiconductor Alloys in the Epitaxial Growth

1994 ◽  
Vol 340 ◽  
Author(s):  
Bing-Lin Gu ◽  
Jing-Zhi Yu ◽  
Xiao Hu ◽  
Kaoru Ohno ◽  
Yoshiyuki Kawazoe
Keyword(s):  
Dynamic Model ◽  
Ground State ◽  
Wave Method ◽  
Semiconductor Alloys ◽  
Concentration Wave ◽  
Surface Layers ◽  
Ordered Structures ◽  
Effective Interactions ◽  
Ternary Semiconductor ◽  
The Difference

ABSTRACTA concentration wave method for several interpenetrating Bravais sublattices is presented by considering the intralayer and interlayer effective interactions and the difference between the surface layers and the deeper layers in III – V alloys. The ground state ordered structures of ternary III – V semiconductor alloys are deduced and a dynamic model is established.

Sign in / Sign up

Export Citation Format

Share Document