The Effect of Modeling Errors on Linear State Reconstructors and Regulators

1974 ◽  
Vol 96 (4) ◽  
pp. 454-459 ◽  
Author(s):  
F. E. Thau ◽  
A. Kestenbaum
Keyword(s):  
Dynamic Systems ◽  
Upper Bound ◽  
Reconstruction Error ◽  
Order Model ◽  
Modeling Errors ◽  
Parameter Variations ◽  
Linear State ◽  
The Stability ◽  
Linear Regulators ◽  
Low Order

The effect of imprecise knowledge of system parameters on the reconstruction error of linear observers and on the stability of a class of linear regulators is examined. An upper bound on the reconstruction error for linear unforced systems is obtained. It is shown that in the regulator problem consideration of parameter uncertainty leads to the inclusion of step disturbances. An upper bound on allowed parameter variations that guarantees stability of a class of closed-loop regulators is obtained. It is also shown that by properly choosing parameters of a low-order observer, the output of this low-order model can be made to follow closely the output of a higher-order dynamic systems. The effect of modeling errors on randomly perturbed systems is also examined.

Optimal low order model identification of fractional dynamic systems

2008 ◽  
Vol 206 (2) ◽  
pp. 543-554 ◽  
Author(s):  
T. Djamah ◽  
R. Mansouri ◽  
S. Djennoune ◽  
M. Bettayeb
Keyword(s):  
Dynamic Systems ◽  
Model Identification ◽  
Order Model ◽  
Low Order

Low-Order Acoustic Modelling for Annular Combustors: Validation and Inclusion of Modal Coupling

2002 ◽  
Author(s):  
Ste´phanie Evesque ◽  
Wolfgang Polifke
Keyword(s):  
Passive Control ◽  
Three Dimensional ◽  
Nonlinear Effects ◽  
Order Model ◽  
Modal Coupling ◽  
Annular Combustor ◽  
Dimensional Finite Element ◽  
The Stability ◽  
Three Dimensional Finite Element ◽  
Low Order

A two-dimensional low-order model of a generic annular premixed combustor, comprising an annular combustion chamber connected to an annular plenum via a finite number of burners, is developed and validated. The shapes and frequencies of the eigenmodes as well as the stability of the combustor against self-excited oscillations can be predicted with such a model. The dynamical characteristics of each burner is described mathematically in terms of its transfer matrix. The case where the transfer matrices of individual burners differ from each other can be handled by the model formulation presented. This is important in situations where non-identical burners are used in an annular combustor as a means of passive control, or where nonlinear effects lead to non-identical burner behaviour. The resulting loss of axisymmetry enhances the coupling between nonplane acoustic modes of different order. This modal coupling is accounted for by the model. The eigenmode shapes and frequencies predicted by the low-order model are validated by comparison with the results of a three-dimensional finite element acoustic model of a generic annular combustor configuration.

Hybrid Reduced Model of Rotor

2013 ◽  
Vol 60 (3) ◽  
pp. 319-333
Author(s):  
Rafał Hein ◽  
Cezary Orlikowski
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Hybrid Model ◽  
Rotor System ◽  
Reduced Model ◽  
Order Model ◽  
Gyroscopic Effect ◽  
Reduced Models ◽  
Rigid Finite Element Method ◽  
Low Order

Abstract In the paper, the authors describe the method of reduction of a model of rotor system. The proposed approach makes it possible to obtain a low order model including e.g. non-proportional damping or the gyroscopic effect. This method is illustrated using an example of a rotor system. First, a model of the system is built without gyroscopic and damping effects by using the rigid finite element method. Next, this model is reduced. Finally, two identical, low order, reduced models in two perpendicular planes are coupled together by means of gyroscopic and damping interaction to form one model of the system. Thus a hybrid model is obtained. The advantage of the presented method is that the number of gyroscopic and damping interactions does not affect the model range

A parametric family of Massey-type methods: inference, prediction, and sensitivity

2020 ◽  
Vol 16 (3) ◽  
pp. 255-269
Author(s):  
Enrico Bozzo ◽  
Paolo Vidoni ◽  
Massimo Franceschet
Keyword(s):  
Quantitative Analysis ◽  
Control Theory ◽  
Dynamic Systems ◽  
Parametric Family ◽  
Time Varying ◽  
Multi Agent ◽  
Key Features ◽  
The Stability ◽  
Agent Coordination ◽  
Time Aware

AbstractWe study the stability of a time-aware version of the popular Massey method, previously introduced by Franceschet, M., E. Bozzo, and P. Vidoni. 2017. “The Temporalized Massey’s Method.” Journal of Quantitative Analysis in Sports 13: 37–48, for rating teams in sport competitions. To this end, we embed the temporal Massey method in the theory of time-varying averaging algorithms, which are dynamic systems mainly used in control theory for multi-agent coordination. We also introduce a parametric family of Massey-type methods and show that the original and time-aware Massey versions are, in some sense, particular instances of it. Finally, we discuss the key features of this general family of rating procedures, focusing on inferential and predictive issues and on sensitivity to upsets and modifications of the schedule.

On-line thermal regulation of a capillary pumped loop via state feedback control using a low order model

2016 ◽  
Vol 108 ◽  
pp. 614-627 ◽  
Author(s):  
Etienne Videcoq ◽  
Manuel Girault ◽  
Vincent Ayel ◽  
Cyril Romestant ◽  
Yves Bertin
Keyword(s):  
Feedback Control ◽  
State Feedback ◽  
State Feedback Control ◽  
Thermal Regulation ◽  
Order Model ◽  
Capillary Pumped Loop ◽  
On Line ◽  
Low Order

Periodic Solutions in Rotor Dynamic Systems With Nonlinear Supports: A General Approach

1989 ◽  
Vol 111 (2) ◽  
pp. 187-193 ◽  
Author(s):  
C. Nataraj ◽  
H. D. Nelson
Keyword(s):  
Dynamic Systems ◽  
Original Problem ◽  
Squeeze Film ◽  
Algebraic Equations ◽  
Trigonometric Collocation ◽  
Nonlinear Algebraic Equations ◽  
The Stability ◽  
Future Work ◽  
Rotor Dynamic ◽  
Large Rotor

A new quantitative method of estimating steady state periodic behavior in nonlinear systems, based on the trigonometric collocation method, is outlined. A procedure is developed to analyze large rotor dynamic systems with nonlinear supports by the use of the above method in conjunction with Component Mode Synthesis. The algorithm discussed is seen to reduce the original problem to solving nonlinear algebraic equations in terms of only the coordinates associated with the nonlinear supports and is a big improvement over commonly used integration methods. The feasibility and advantages of the procedure so developed are illustrated with the help of an example of a typical rotor dynamic system with an uncentered squeeze film damper. Future work on the investigation of the stability of the periodic response so obtained is outlined.

Yield Design of the Reinforced Embankment

2011 ◽  
Vol 368-373 ◽  
pp. 2804-2807
Author(s):  
Bing Zhang ◽  
Xiao Mou Wang
Keyword(s):  
Upper Bound ◽  
Design Approach ◽  
Stability Factor ◽  
Multiphase Model ◽  
Construction Process ◽  
Backfill Soil ◽  
Geotechnical Structures ◽  
The Stability ◽  
Kinematic Approach

A frequently used technique for improving the performance of geotechnical structures consists in incorporating into the backfill soil, during the construction process, regularly spaced thin reinforcing inclusions, called geotextile, geomembranes or geogrids. The stability of embankment, stabilized by reinforcing membranes, is investigated by means of a multiphase model developed in the framework of the yield design approach. By means of the kinematic approach, leading to upper bound estimates for the stability factor of the structure.

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