Optimisation and implementation of a nonlinear identification procedure for unknown Ics

2010 ◽  
Author(s):  
M. Brutscheck ◽  
B. Schmidt ◽  
M. Franke ◽  
A.T. Schwarzbacher ◽  
S. Becker
Keyword(s):  
Nonlinear Identification ◽  
Identification Procedure

Nonlinear Identification of Mechanical Parameters in a Squeeze Film Damper With Integral Mechanical Seal

2009 ◽  
Vol 131 (4) ◽  
Author(s):  
Adolfo Delgado ◽  
Luis San Andrés
Keyword(s):  
Dry Friction ◽  
Test System ◽  
Forced Response ◽  
Squeeze Film ◽  
Inertia Force ◽  
Mechanical Seal ◽  
Nonlinear Identification ◽  
Identification Procedure ◽  
Equivalent Viscous Damping ◽  
Force Coefficients

End seals in squeeze film dampers (SFDs) aid to increase their damping capability while maintaining low lubricant flow rates and reducing the severity of air ingestion. This paper presents measurements of the forced response in a SFD integrating a contacting end seal and with closed flow ports, i.e., no lubricant through flow. The system motion is nonlinear due to the dry-friction interaction at the mechanical seal mating surfaces. Single parameter characterization of the test system would yield an equivalent viscous damping coefficient that is both frequency and motion amplitude dependent. Presently, an identification method suited for nonlinear systems allows determining simultaneously the squeeze film damping and inertia force coefficients and the seal dry-friction force. The identification procedure shows similar (within 10%) force coefficients than those obtained with a more involved two-step procedure that first requires measurements without any lubricant in the test system. The identified SFD damping and inertia force coefficients agree well with model predictions that account for end flow effects at recirculation grooves. The overall test results demonstrate that the nonrotating end seal effectively eliminates side leakage and avoids air ingestion, thus maintaining a consistent damping performance throughout the test frequency range. The nonlinear identification procedure saves time and resources while producing reliable physical parameter estimations.

Nonlinear Identification of Mechanical Parameters in a Squeeze Film Damper With Integral Mechanical Seal

2008 ◽  
Author(s):  
Adolfo Delgado ◽  
Luis San Andre´s
Keyword(s):  
Dry Friction ◽  
Test System ◽  
Forced Response ◽  
Squeeze Film ◽  
Inertia Force ◽  
Mechanical Seal ◽  
Nonlinear Identification ◽  
Identification Procedure ◽  
Equivalent Viscous Damping ◽  
Force Coefficients

End seals in squeeze film dampers (SFDs) aid to increase their damping capability while maintaining low lubricant flow rates and reducing the severity of air ingestion. This paper presents measurements of the forced response in a SFD integrating a contacting end seal and with closed flow ports, i.e. no lubricant thru flow. The system motion is non-linear due to dry friction interaction at the mechanical seal mating surfaces. Single parameter characterization of the test system would yield an equivalent viscous damping coefficient that is both frequency and motion amplitude dependent. Presently, an identification method suited for nonlinear systems allows determining simultaneously the squeeze film damping and inertia force coefficients and the seal dry friction force. The identification procedure shows similar (within 10%) force coefficients than those obtained with a more involved two-step procedure that first requires measurements without any lubricant in the test system. The identified SFD damping and inertia force coefficients agree well with model predictions that account for end flow effects at recirculation grooves. The overall test results demonstrate that the non-rotating end seal effectively eliminates side leakage and avoids air ingestion; thus maintaining a consistent damping performance throughout the test frequency range. The nonlinear identification procedure saves time and resources while producing reliable physical parameter estimations.

Application of Quaternion Numbers in Identification Scheme

2015 ◽  
Vol 3 (2) ◽  
Author(s):  
Reza Alimoradi
Keyword(s):  
Access Control ◽  
Control Methods ◽  
Identification Procedure ◽  
Identification Scheme

The goal of an identification procedure is access control. Methods that permit an identification are called identification protocols. In this paper, first we introduced quaternion numbers. In addition we proposed a new identification scheme based on quaternions. Finally, the security of our scheme is analyzed.

scholarly journals The Loewner framework for nonlinear identification and reduction of Hammerstein cascaded dynamical systems

PAMM ◽  
2021 ◽  
Vol 20 (1) ◽  
Author(s):  
Dimitrios S. Karachalios ◽  
Ion Victor Gosea ◽  
Athanasios C. Antoulas
Keyword(s):  
Dynamical Systems ◽  
Nonlinear Identification

scholarly journals Research and dynamic analysis based on nonlinear identification of sports goods Econometrics

2021 ◽  
Vol 1802 (2) ◽  
pp. 022035
Author(s):  
Chunhua Yang ◽  
Wanjun Zhang ◽  
Feng Zhang ◽  
Xiaoping Gou ◽  
Jingxuan Zhang ◽  
...  
Keyword(s):  
Dynamic Analysis ◽  
Nonlinear Identification ◽  
Sports Goods
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