Time-Domain Hydroelastic Analysis of a Flexible Marine Structure Using State-Space Models

2008 ◽  
Vol 131 (1) ◽  
Author(s):  
Reza Taghipour ◽  
Tristan Perez ◽  
Torgeir Moan
Keyword(s):  
State Space ◽  
Time Domain ◽  
State Space Model ◽  
Space Representation ◽  
Regular Waves ◽  
State Space Representation ◽  
Alternative State ◽  
Marine Structure ◽  
Hydroelastic Analysis ◽  
The Mathematical Model

This article deals with time-domain hydroelastic analysis of a marine structure. The convolution terms associated with fluid memory effects are replaced by an alternative state-space representation, the parameters of which are obtained by using realization theory. The mathematical model established is validated by comparison to experimental results of a very flexible barge. Two types of time-domain simulations are performed: dynamic response of the initially inert structure to incident regular waves and transient response of the structure after it is released from a displaced condition in still water. The accuracy and the efficiency of the simulations based on the state-space model representations are compared to those that integrate the convolutions.

Time Domain Hydroelastic Analysis of a Flexible Marine Structure Using State-Space Models

2007 ◽  
Author(s):  
Reza Taghipour ◽  
Tristan Perez ◽  
Torgeir Moan
Keyword(s):  
Mathematical Model ◽  
State Space ◽  
Time Domain ◽  
State Space Model ◽  
Realization Theory ◽  
Regular Waves ◽  
Alternative State ◽  
Marine Structure ◽  
Hydroelastic Analysis ◽  
The Mathematical Model

This article deals with time-domain hydroelastic analysis of a marine structure. The convolution terms in the mathematical model are replaced by their alternative state-space representations whose parameters are obtained by using the realization theory. The mathematical model is validated by comparison to experimental results of a very flexible barge. Two types of time-domain simulations are performed: dynamic response of the initially inert structure to incident regular waves and transient response of the structure after it is released from a displaced condition in still water. The accuracy and the efficiency of the simulations based on the state-space model representations are compared to those that integrate the convolutions.

Analysis and Design of the LLC LED Driver Based on State-Space Representation Direct Time-Domain Solution

2020 ◽  
Vol 35 (12) ◽  
pp. 12686-12701
Author(s):  
Maikel F. Menke ◽  
Joao P. Duranti ◽  
Leandro Roggia ◽  
Fabio E. Bisogno ◽  
Rodrigo V. Tambara ◽  
...  
Keyword(s):  
State Space ◽  
Time Domain ◽  
Space Representation ◽  
Led Driver ◽  
Analysis And Design ◽  
State Space Representation

State-space representation of radiation forces in time-domain vessel models

2005 ◽  
Vol 32 (17-18) ◽  
pp. 2195-2216 ◽  
Author(s):  
Erlend Kristiansen ◽  
Åsmund Hjulstad ◽  
Olav Egeland
Keyword(s):  
State Space ◽  
Time Domain ◽  
Space Representation ◽  
State Space Representation ◽  
Radiation Forces

Fixed causality slip-stick friction models for use in simulation of non-linear systems

2005 ◽  
Vol 219 (3) ◽  
pp. 199-206 ◽  
Author(s):  
D Margolis
Keyword(s):  
State Space ◽  
Sliding Friction ◽  
State Space Model ◽  
Electric Circuit ◽  
Friction Model ◽  
Space Representation ◽  
State Space Representation ◽  
System A ◽  
Friction Models ◽  
Order State

Slip-stick friction occurs when the relative velocity between sliding surfaces approaches zero and the surfaces become ‘stuck’, requiring a force larger than the sliding friction force to break the surfaces loose, allowing sliding to resume. Mathematically, these physics are an example of ‘ideal switching’ where the velocity is zero and the force is determined by other parts of the system, or the force is set by the friction model (and could be zero), and the velocity is determined by other parts of the system. A switch in an electric circuit is another example. Including ideal switches in an overall physical system model is complicated by the inversion of causality when the switch occurs. In one state the velocity is prescribed and the force is determined, and in the other state the force is prescribed and the velocity is determined. Such causal inversions create formulation and computational problems, and these problems can be quite prohibitive if many switches are part of the model. This paper presents fixed causal models for slip-stick friction that allow a single state space model to be used regardless of the number of switches. Such a development allows simulation of multiple plate brakes and clutches, or ideal rectifiers, using an explicit first-order state space representation. It should be noted that there has been extensive work in the development of models that represent the physics of friction. One such model is the LuGre model [1] where microstructural displacements are modelled. Our intent here is not to extend the physics of slip-stick friction, but rather to reasonably represent the physics while providing a computationally convenient method for including slip-stick friction in overall system models.

scholarly journals Model predictive control for a multiple injection combustion model

2021 ◽  
Vol 11 (1) ◽  
pp. 1134-1140
Author(s):  
Hoang Nguyen Khac ◽  
Amin Modabberian ◽  
Xiaoguo Storm ◽  
Kai Zenger ◽  
Jari Hyvönen
Keyword(s):  
State Space ◽  
State Space Model ◽  
Space Representation ◽  
Combustion Model ◽  
Multiple Injection ◽  
Engine Model ◽  
State Space Representation ◽  
Indicated Mean Effective Pressure ◽  
Start Of Injection ◽  
Predictive Controller

Abstract In this work, a model predictive controller is developed for a multiple injection combustion model. A 1D engine model with three distinct injections is used to generate data for identifying the state-space representation of the engine model. This state-space model is then used to design a controller for controlling the start of injection and injected fuel mass of the post injection. These parameters are used as inputs for the engine model to control the maximum cylinder pressure and indicated mean effective pressure.

An investigation into a state space model for an attenuator in automotive hydraulic systems

2003 ◽  
Vol 217 (1) ◽  
pp. 63-67 ◽  
Author(s):  
J-C Lee
Keyword(s):  
State Space ◽  
Time Domain ◽  
State Space Model ◽  
The State ◽  
Dynamic Responses ◽  
Space Representation ◽  
Response Analysis ◽  
Space Model ◽  
Electrical Analogy ◽  
The Time Domain

A hydraulic attenuator has been used in hydraulic active suspension systems of automotive vehicles to reduce high amplitude ripple pressure of a pump. The hydraulic attenuator considered in this study is so highly non-linear and of high order that the analysis in the time domain has been performed infrequently, although the frequency response analysis with the transfer matrix method was applicable. In this paper, a state space representation of the dynamics for a hydraulic attenuator is presented, utilizing the electrical analogy. The results of the experiment are compared with those of the simulation to validate the state space model proposed. The comparison reveals that the state space model proposed is practically applicable for estimating the dynamic responses of the hydraulic attenuator in the time domain.

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