Closed-Loop Grammians and model reduction for decentralized control of flexible structures

1996 ◽  
Author(s):  
Jianguo Wu ◽  
Trevor Williams
Keyword(s):  
Model Reduction ◽  
Decentralized Control ◽  
Closed Loop ◽  
Flexible Structures

scholarly journals Optimal and Decentralized Control Strategies for Inverter-Based AC Microgrids

Energies ◽  
2019 ◽  
Vol 12 (18) ◽  
pp. 3529 ◽  
Author(s):  
Michael D. Cook ◽  
Eddy H. Trinklein ◽  
Gordon G. Parker ◽  
Rush D. Robinett ◽  
Wayne W. Weaver
Keyword(s):  
Decentralized Control ◽  
Closed Loop ◽  
Exergy Analysis ◽  
Control Strategies ◽  
Distributed Storage ◽  
Droop Control ◽  
Exergy Destruction ◽  
High Penetration ◽  
Feedforward Controller ◽  
Fully Connected

This paper presents two control strategies: (i) An optimal exergy destruction (OXD) controller and (ii) a decentralized power apportionment (DPA) controller. The OXD controller is an analytical, closed-loop optimal feedforward controller developed utilizing exergy analysis to minimize exergy destruction in an AC inverter microgrid. The OXD controller requires a star or fully connected topology, whereas the DPA operates with no communication among the inverters. The DPA presents a viable alternative to conventional P − ω / Q − V droop control, and does not suffer from fluctuations in bus frequency or steady-state voltage while taking advantage of distributed storage assets necessary for the high penetration of renewable sources. The performances of OXD-, DPA-, and P − ω / Q − V droop-controlled microgrids are compared by simulation.

Closed-Loop Input Shaping for Flexible Structures Using Time-Delay Control1

1999 ◽  
Vol 122 (3) ◽  
pp. 454-460 ◽  
Author(s):  
Vikram Kapila ◽  
Anthony Tzes ◽  
Qiguo Yan
Keyword(s):  
Time Delay ◽  
Closed Loop ◽  
Flexible Structures ◽  
System Stability ◽  
Structural Vibration ◽  
Delay Systems ◽  
Linear Matrix ◽  
Input Shaping ◽  
Closed Loop Control ◽  
Loop Control

Input shaping techniques reduce the residual vibration in flexible structures by convolving the command input with a sequence of impulses. The exact cancellation of the residual structural vibration via input shaping is dependent on the amplitudes and instances of impulse application. A majority of the current input shaping schemes are inherently open-loop where impulse application at inaccurate instances can lead to system performance degradation. In this paper, we develop a closed-loop control design framework for input shaped systems. This framework is based on the realization that the dynamics of input shaped systems give rise to time delays in the input. Thus, we exploit the feedback control theory of time delay systems for the closed-loop control of input shaped flexible structures. A Riccati equation-based and a linear matrix inequality-based frameworks are developed for the stabilization of systems with uncertain, multiple input delays. Next, the aforementioned framework is applied to two input shaped flexible structure systems. This framework guarantees closed-loop system stability and performance when the impulse train is applied at inaccurate instances. Two illustrative numerical examples demonstrate the efficacy of the proposed closed-loop input shaping controller. [S0022-0434(00)00103-9]

Reduced modeling of flexible structures for decentralized control

1986 ◽  
Author(s):  
A. Yousuff ◽  
T. Tan ◽  
L. Bahar ◽  
M. Konstantinidis
Keyword(s):  
Decentralized Control ◽  
Flexible Structures ◽  
Reduced Modeling

Reduction Methods of Structure Models for Control System Purposes

2016 ◽  
Vol 248 ◽  
pp. 119-126 ◽  
Author(s):  
Andrzej Koszewnik ◽  
Zdzisław Gosiewski
Keyword(s):  
Control System ◽  
High Frequency ◽  
Closed Loop ◽  
Flexible Structures ◽  
Low Frequency ◽  
Point Of View ◽  
Closed Loop Systems ◽  
System A ◽  
Reduction Methods ◽  
The Stability

To design vibration control system for flexible structures their mathematical model should be reduced. In the paper we consider the influence of the model reduction on the dynamics of the real closed-loop system. A simply cantilever beam is an object of consideration since we are able to formulate the exact analytical model of such structure. As a result of reduction the model with low frequency resonances is usually separated from the high frequency dynamics because high frequency part of the model is naturally strong damped. In order to estimate dynamical system for control purposes in the paper we applied a few orthogonal methods such as: modal, Rayleigh-Ritz and Schur decompositions. As it is shown all methods well calculate resonances frequencies but generate different anti-resonances frequencies. From control strategy in point of view of the flexible structures these anti-resonances have significantly influence on the stability and dynamics of the closed-loop systems.

Switching decentralized control of a platoon of vehicles with time-varying heterogeneous delay: A safe and dense spacing policy

2017 ◽  
Vol 232 (8) ◽  
pp. 1036-1046 ◽  
Author(s):  
Hossein Chehardoli ◽  
Mohammad R. Homaeinezhad
Keyword(s):  
Decentralized Control ◽  
Closed Loop ◽  
Delay Systems ◽  
Internal Stability ◽  
Time Varying ◽  
Simulation Studies ◽  
Control Parameters ◽  
Communication Structure ◽  
Loop Dynamics ◽  
Relative Measurements

In this paper the problem of decentralized switching control of a platoon of vehicles in the presence of heterogeneous time-varying communication and parasitic delays is investigated. A neighbor-based linear decentralized controller using the relative measurements is considered for each vehicle. The communication structure of the platoon is assumed to be time-varying. Therefore, the closed-loop dynamics of the platoon is in the form of switched linear multiple-delay systems. Compared to previous research, the communication structure of the platoon is assumed to be general. A safe and dense spacing policy is used to adjust inter-vehicle distances. The internal stability analysis of the platoon is done by employing Lyapunov–Razumikhin and Lyapunov–Krasovskii theorems. Afterwards, some conditions on control parameters assuring string stability are obtained by introducing a new theorem. Simulation studies are carried out to show the effectiveness of the proposed methods.

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