Modeling of Trabecular Architecture as Result of an Optimal Control Procedure

2012 ◽  
pp. 19-37 ◽  
Author(s):  
Ugo Andreaus ◽  
Michele Colloca ◽  
Daniela Iacoviello
Keyword(s):  
Optimal Control ◽  
Control Procedure ◽  
Trabecular Architecture

scholarly journals Thermal Effects on Vibration and Control of Piezocomposite Kirchhoff Plate Modeled by Finite Elements Method

2015 ◽  
Vol 2015 ◽  
pp. 1-15 ◽  
Author(s):  
M. Sanbi ◽  
R. Saadani ◽  
K. Sbai ◽  
M. Rahmoune
Keyword(s):  
Optimal Control ◽  
Finite Element ◽  
Thermal Effects ◽  
Thermal Gradient ◽  
Active Vibration Control ◽  
Control Procedure ◽  
Finite Element Approximations ◽  
Plate Vibrations ◽  
Active Vibration ◽  
And Control

Theoretical and numerical results of the modeling of a smart plate are presented for optimal active vibration control. The smart plate consists of a rectangular aluminum piezocomposite plate modeled in cantilever configuration with surface bonded thermopiezoelectric patches. The patches are symmetrically bonded on top and bottom surfaces. A generic thermopiezoelastic theory for piezocomposite plate is derived, using linear thermopiezoelastic theory and Kirchhoff assumptions. Finite element equations for the thermopiezoelastic medium are obtained by using the linear constitutive equations in Hamilton’s principle together with the finite element approximations. The structure is modelled analytically and then numerically and the results of simulations are presented in order to visualize the states of their dynamics and the state of control. The optimal control LQG-Kalman filter is applied. By using this model, the study first gives the influences of the actuator/sensor pair placement and size on the response of the smart plate. Second, the effects of thermoelastic and pyroelectric couplings on the dynamics of the structure and on the control procedure are studied and discussed. It is shown that the effectiveness of the control is not affected by the applied thermal gradient and can be applied with or without this gradient at any time of plate vibrations.

An optimal control approach for alleviation of tiltrotor gust response

2012 ◽  
Vol 116 (1180) ◽  
pp. 651-666 ◽  
Author(s):  
D. Muro ◽  
M. Molica Colella ◽  
J. Serafini ◽  
M. Gennaretti
Keyword(s):  
Optimal Control ◽  
Body Motion ◽  
Control Procedure ◽  
State Estimate ◽  
Control Approach ◽  
Pilot Model ◽  
Aeroelastic Model ◽  
Control Methodology ◽  
Optimal Control Approach ◽  
Gust Response

Abstract The alleviation of gusts effects on a tiltrotor in aeroplane and helicopter operation modes obtained by an optimal control methodology based on the actuation of elevators, wing flaperons and swashplate is examined. An optimal observer for state estimate is included in the compensator synthesis, with the Kalman-Bucy filter applied in the presence of stochastic noise. Tiltrotor dynamics is simulated through an aeroelastic model that couples rigid-body motion with wing and proprotor structural dynamics. An extensive numerical investigation examines effectiveness and robustness of the applied control procedure, taking into account the action of both deterministic and stochastic vertical gusts. In addition, a passive pilot model is included in the aeroelastic loop and the corresponding effects on uncontrolled and controlled gust response are analysed.

Optimal Control Procedure Application for Dynamic Response of Adaptive Aircraft Wings Modeled as Thin-Walled Composite Beams

2015 ◽  
Vol 798 ◽  
pp. 292-296 ◽  
Author(s):  
Kaan Yildiz ◽  
Seher Eken ◽  
Metin Orhan Kaya
Keyword(s):  
Optimal Control ◽  
Dynamic Response ◽  
Dynamical Behavior ◽  
Active Vibration Control ◽  
Feedback Gain ◽  
Control Procedure ◽  
Control Effort ◽  
Aircraft Wings ◽  
Active Vibration ◽  
Thin Walled

In this study we investigated the dynamical behavior of aircraft wings and using piezoelectric actuation we implemented active vibration control. The aircraft wing is modeled as a thin-walled composite beam having a cross section of diamond shaped. The dynamic response of the beam under varying proportional and velocity feedback gain parameters is obtained and shown to be enhanced with optimal control procedure, minimizing the control effort and response.

scholarly journals Thermoelastic and Pyroelectric Couplings Effects on Dynamics and Active Control of Smart Piezolaminated Beam Modeled by Finite Element Method

2014 ◽  
Vol 2014 ◽  
pp. 1-10 ◽  
Author(s):  
M. Sanbi ◽  
R. Saadani ◽  
K. Sbai ◽  
M. Rahmoune
Keyword(s):  
Optimal Control ◽  
Finite Element ◽  
High Performance ◽  
Structural Systems ◽  
Control Procedure ◽  
Finite Element Approximations ◽  
Active Structures ◽  
Piezoelectric Beam ◽  
Control Electronics ◽  
And Control

Smart structures with integrated sensors, actuators, and control electronics are of importance to the next generation high-performance structural systems. In this study, thermopiezoelastic characteristics of piezoelectric beam continua are studied and applications of the theory to active structures in sensing and optimal control are discussed. Using linear thermopiezoelastic theory and Timoshenko assumptions, a generic thermopiezoelastic theory for piezolaminated composite beam is derived. Finite element equations for the thermopiezoelastic media are obtained by using the linear constitutive equations in Hamilton's principle together with the finite element approximations. The structure consists of a modeling of cantilevered piezolaminated Timoshenko beam with integrated thermopiezoelectric elements between two aluminium layers. The structure is modelled analytically and then numerically and the results of simulations are presented in order to visualize the states of their dynamics and the state of control. The optimal control LQG accompanied by the Kalman filter is applied. The effects of thermoelastic and pyroelectric couplings on the dynamics of the structure and on the control procedure are studied and discussed. We show that the control procedure cannot be perturbed by applying a thermal gradient and the control can be applied at any time during the period of vibration of the beam.

An Optimal Control Procedure based on Multivariate Synthetic Cumulative Sum

2013 ◽  
Vol 30 (7) ◽  
pp. 1049-1058 ◽  
Author(s):  
Ming Ha Lee ◽  
Michael B. C. Khoo ◽  
Min Xie
Keyword(s):  
Optimal Control ◽  
Control Procedure ◽  
Cumulative Sum

scholarly journals Suppression of Base Excitation of Rotors on Magnetic Bearings

2007 ◽  
Vol 2007 ◽  
pp. 1-10 ◽  
Author(s):  
Steven Marx ◽  
C. Nataraj
Keyword(s):  
Optimal Control ◽  
Magnetic Bearings ◽  
Control Technique ◽  
System Response ◽  
Control Procedure ◽  
Base Excitation ◽  
Current Function ◽  
Rotor Systems ◽  
Moving Platforms ◽  
Highly Nonlinear

This paper deals with rotor systems that suffer harmonic base excitation when supported on magnetic bearings. Magnetic bearings using conventional control techniques perform poorly in such situations mainly due to their highly nonlinear characteristics. The compensation method presented here is a novel optimal control procedure with a combination of conventional, proportional, and differential feedback control. A four-degree-of-freedom model is used for the rotor system, and the bearings are modeled by nonlinear expressions. Each disturbance frequency is expected to produce a multiharmonic system response, a characteristic of nonlinear systems. We apply optimal control choosing to minimize a performance index, which leads to the optimization of the trigonometric coefficients in the correction current function. Results show that the control technique suppresses rotor vibration to amplitudes that were significantly smaller than the disturbance amplitudes for the entire range of disturbance frequencies applied. The control technique explored in this paper is a promising step towards the successful application of magnetic bearings to systems mounted on moving platforms.

Genetic Algorithms for Traffic Signal Control and Queue Management of Oversaturated Two-Way Arterials

2000 ◽  
Vol 1727 (1) ◽  
pp. 61-67 ◽  
Author(s):  
Ghassan Abu-Lebdeh ◽  
Rahim F. Benekohal
Keyword(s):  
Optimal Control ◽  
Genetic Algorithms ◽  
Main Idea ◽  
Signal Control ◽  
Traffic Signal Control ◽  
Control Procedure ◽  
Queue Management ◽  
Management Algorithm ◽  
Management Schemes ◽  
Primary Direction

The formulation and solution of a dynamic signal control and queue management algorithm for two-way oversaturated arterials are presented. The algorithm is structured to find optimal control and queue management in at least one direction: the primary direction. The other direction is optimized only subject to the fulfillment of the constraints on the primary direction. The main idea of the procedure is to manage queue formation and dissipation through proper design of signal control parameters such that queues are always contained within respective links and that spillbacks are prevented. The two-way control procedure presented accounts for all possible traffic flow regimes that may form as a result of queue management schemes. Genetic algorithms were used to solve the problem. The results show that although the algorithm provides optimal control and queue management in the primary direction, it was also able to manage queues in the secondary direction so that the occurrence of queue spillbacks is prevented. Progression was attainable only in the primary direction. However, the algorithm was able to effectively deal with evolving traffic queues in both directions. In all but one link, traffic was successfully contained in the respective links, thus preventing spillback.

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