Energy balances in dynamic systems in the presence of unmodelled dynamics by using specifications in the frequency domain

1990 ◽  
Vol 137 (1) ◽  
pp. 41 ◽  
Author(s):  
M. de la Sen
Keyword(s):  
Frequency Domain ◽  
Dynamic Systems ◽  
Energy Balances

Treating Uncertainties in Multibody Dynamic Systems Using a Polynomial Chaos Spectral Decomposition

2004 ◽  
Author(s):  
Corina Sandu ◽  
Adrian Sandu ◽  
Brendan J. Chan ◽  
Mehdi Ahmadian
Keyword(s):  
Frequency Domain ◽  
Dynamic Systems ◽  
Time Domain ◽  
Spectral Decomposition ◽  
Polynomial Chaos ◽  
Model Uncertainties ◽  
Dynamic Simulations ◽  
Computational Tools ◽  
Model Complex ◽  
Multibody Dynamic

This study addresses the critical need for computational tools to model complex nonlinear multibody dynamic systems in the presence of parametric and external uncertainty. Polynomial chaos has been used extensively to model uncertainties in structural mechanics and in fluids, but to our knowledge they have yet to be applied to multibody dynamic simulations. We show that the method can be applied to quantify uncertainties in time domain and frequency domain.

Optimization of Complex Dynamic Systems With Respect to Their Behavior in Time and Frequency Domain

2011 ◽  
Author(s):  
Matthias Marx ◽  
Chunsheng Wei ◽  
Dirk So¨ffker
Keyword(s):  
Frequency Domain ◽  
Dynamic Systems ◽  
Power Flow ◽  
Dynamical Behavior ◽  
Magnetic Bearing ◽  
Rotor System ◽  
Active Magnetic Bearing ◽  
Design Parameters ◽  
Powertrain System ◽  
Aging Mechanisms

This paper describes an integrated optimization process of dynamic systems including design parameters and control algorithms. In contrast to known approaches the developed approach is based on an optimization loop including the evaluation of the dynamical behavior of technical systems with respect to the behavior and related properties in time and frequency domain. This includes as well the behavior of the system, the objective function as the formulation of the restrictions to be considered for the dynamical behavior (stationary and instationary). The proposed approach is declared in detail and will be illustrated using two typical technical applications as examples. The first application example is the optimization of the control system of an active magnetic bearing (AMB) rotor system. Hereby the modeling of the AMB rotor system is briefly introduced. An H∞ controller is designed for the control of the system. The performance both in time and frequency domain is optimized in parallel. The algorithm will be explained by simulation examples. The second example is the optimization of the pow-ermanagement system of a fuel cell/supercap-based hybrid electric powertrain. Hereby the modeling of the electric power flow within the powertrain system is demonstrated and its influence on certain system properties like availability, efficiency, and typical aging mechanisms is discussed. The proposed method leads to near-optimal results in a few steps for both of the systems introduced.

The frequency domain evaluation of mathematical models for dynamic systems

AIChE Journal ◽  
1967 ◽  
Vol 13 (2) ◽  
pp. 374-378 ◽  
Author(s):  
James R. Hays ◽  
William C. Clements ◽  
Thomas R. Harris
Keyword(s):  
Mathematical Models ◽  
Frequency Domain ◽  
Dynamic Systems
Sign in / Sign up

Export Citation Format

Share Document