This study aimed at developing artificial-intelligence-(AI)-theory-based optimal control algorithms for improving the indoor temperature conditions and heating energy efficiency of the double-skin buildings. For this,...
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This study aimed at developing artificial-intelligence-(AI)-theory-based optimal control algorithms for improving the indoor temperature conditions and heating energy efficiency of the double-skin buildings. For this, one conventional rule-based and four AI-based algorithms were developed, including artificial neural network (ANN), fuzzy logic (FL), and adaptive neuro fuzzy inference systems (ANFIS), for operating the surface openings of the double skin and the heating system. A numerical computer simulation method incorporating the matrix laboratory (MATLAB) and the transient systems simulation (TRNSYS) software was used for the comparative performance tests. The analysis results revealed that advanced thermal-environment comfort and stability can be provided by the AI-based algorithms. In particular, the FL and ANFIS algorithms were superior to the ANN algorithm in terms of providing better thermal conditions. The ANN-based algorithm, however, proved its potential to be the most energy-efficient and stable strategy among the four AI-based algorithms. It can be concluded that the optimal algorithm can be differently determined according to the major focus of the strategy. If comfortable thermal condition is the principal interest, then the FL or ANFIS algorithm could be the proper solution, and if energy saving for space heating and system operation stability is the main concerns, then the ANN-based algorithm may be applicable. (C) 2015 Elsevier Ltd. All rights reserved.
Cooling is essential for electronic devices. This perspective proposes a comprehensive framework to elaborate on the classification, evaluation criteria, and application scenarios of various cooling technologies. Give...
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Cooling is essential for electronic devices. This perspective proposes a comprehensive framework to elaborate on the classification, evaluation criteria, and application scenarios of various cooling technologies. Given the importance of passive cooling, the theories and applications of several cutting-edge passive cooling technologies are discussed, including soft-control cooling (i.e., the design of temperature control algorithms), sky radiative cooling, and sorption-based evaporative cooling. Soft-control cooling ensures that devices operate under optimal conditions by dynamically adapting to varying thermal environments. Radiative and evaporative cooling leverage the transformative use of the cold universe and ambient humidity, rather than conventional ambient temperature, as cold sinks to enhance cooling power. After identifying the challenges and opportunities, this perspective highlights the importance of combining different cooling technologies, particularly integrating hardware-based solutions with soft algorithms, to improve system performance and effectively address the "dark silicon"problem.
The linear quadratic regulator (LQR) control algorithm is at the heart of many modem control design methods. There have been numerous publications dealing with LQR control and earthquake engineering. However, very few...
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The linear quadratic regulator (LQR) control algorithm is at the heart of many modem control design methods. There have been numerous publications dealing with LQR control and earthquake engineering. However, very few papers discuss the hysteretic loops produced by the LQR control force, although in the earthquake engineering field, hysteretic loops have been the key part of seismic designs. This paper shows the importance of investigating the hysteretic loops produced by the LQR control force for seismic response, and proposes a method to reproduce the hysteretic loops with a much simpler algorithm. The investigation was carried out on a cable-stayed bridge model controlled either by the LQR algorithm, viscous damper, or the proposed method. The results show that the proposed method is capable of reducing seismic response better than the viscous damper case and is similar to the LQR case. The practical applicability of the proposed method is also investigated by using a variable-orifice oil damper as the controlling device. The proposed method needs only displacement response at the device location, and therefore fewer sensors are needed than for the LQR algorithm. Copyright (c) 2005 John Wiley & Sons, Ltd.
A control scheme using a feedback-assisted iterative learning control algorithm to maintain the optimal ethanol concentration for the enhancement of cell growth and emulsan production in fed-batch cultivation of Acine...
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A control scheme using a feedback-assisted iterative learning control algorithm to maintain the optimal ethanol concentration for the enhancement of cell growth and emulsan production in fed-batch cultivation of Acinetobacter calcoaceticus RAG-1 is presented. The optimal concentration of ethanol for cell growth and emulsan production was determined by considering the inhibitory effect of ethanol. To maintain the optimal concentration of ethanol, continuous feeding of ethanol was adopted using the feedback-assisted iterative learning control algorithm. A mathematical kinetic model is used to simulate the objective process. The transfer function of the objective process was approximated to the FOPDT (First Order Plus Dead Time) model and model parameters were determined by the LSE (Least Square Estimation) method. In the transfer function modeling, to evaluate the process model parameters which can describe the objective process, the disturbance included in the process was eliminated by linearization of two data sets of preliminary fed-batch runs. Fed-batch cultivation experiments using a feedback-assisted learning control algorithm were performed. The results showed that the convergence performance was improved as the run was iterated and the emulsan yield was increased compared with that of the runs controlled by only the feedback loop.
The range-rate control algorithm (RRCA) and its omnidirectional (ODRRCA) modification for space rendezvous are based on nonlinear dynamical system theory, and have thus far been effective only in cases where a target ...
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The range-rate control algorithm (RRCA) and its omnidirectional (ODRRCA) modification for space rendezvous are based on nonlinear dynamical system theory, and have thus far been effective only in cases where a target spacecraft is in a circular orbit. The more complex case of an elliptic-orbit rendezvous is addressed, using three generalized schemes for terminal rendezvous control: RRCA-based, ODRRCA-based, and combined RRCA/ODRRCA. Both fixed and variable-thust cases are treated. (AIAA)
An LLC resonant converter has been widely used in various industrial applications because of its high cost-effectiveness, high power conversion efficiency, simple design methodology, and simple control algorithms usin...
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An LLC resonant converter has been widely used in various industrial applications because of its high cost-effectiveness, high power conversion efficiency, simple design methodology, and simple control algorithms using a pulse frequency modulation (PFM). In addition, the soft switching capability of the LLC resonant converter is good to obtain high switching frequency operations, which can get the high-power density of the power converter. Over the past years, several studies have been conducted to improve the performance of a high switching frequency LLC resonant converter with resonant tank design, optimal power stage design, and enhanced control algorithms. This paper is the review paper in terms of the control algorithms for the LLC resonant converter. It focuses on the overview of the high switching-frequency LLC resonant converter in terms of the control algorithms. The advanced control algorithm can improve power conversion efficiency, dynamic performance, tight output voltage regulation, and small electro-magnetic interference. The operational principles of the control algorithms are briefly explained to show their own characteristics and advantages. Thereafter, the research issues for the future works will be discussed in the conclusion.
Implementation of genetic algorithm in a PIC32MX microcontroller-based polarization control system is proposed and demonstrated. The controller measures the signal intensity that is used to estimate the genetic value....
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Implementation of genetic algorithm in a PIC32MX microcontroller-based polarization control system is proposed and demonstrated. The controller measures the signal intensity that is used to estimate the genetic value. This process is controlled by the genetic algorithm rather than referring to the Look-Up-Table as implemented in existing solutions. To reach optimum performance, the code is optimized by using the best genetic parameters so that the fastest execution time can be achieved. An ability of genetic algorithm to work efficiently in polarization control system possesses many advantages including easy code construction, low memory consumption and fast control speed. Genetic algorithm is intelligent enough to be used for endless polarization stabilization and in the worst case, able to stabilize the polarization changes in 300 vs. In the best case the response time can reach 17 mu s. (C) 2012 Elsevier Ltd. All rights reserved.
This article provides an overview of control algorithms for grid-connected converters in renewable energy systems, demonstrating their relevance and potential for further research. A common issue among authors of scie...
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This article provides an overview of control algorithms for grid-connected converters in renewable energy systems, demonstrating their relevance and potential for further research. A common issue among authors of scientific works is the lack of a wide range of conducted research. Often, the results showing the operation of the developed algorithms in transient states or under abnormal supply conditions (such as asymmetries and distortions) are missing. This significantly reduces the ability to compare developed solutions, making it difficult to choose the appropriate control method for future research. The article suggests which control algorithm for power converters is best suited for research considering various factors.
For one class of multivariable linear interlinked objects, a calculation is given for compensation of the dynamic mutual interaction between separate subsystems. algorithms are developed for synthesizing the control l...
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For one class of multivariable linear interlinked objects, a calculation is given for compensation of the dynamic mutual interaction between separate subsystems. algorithms are developed for synthesizing the control law for a multivariable linear system. The effectiveness of the control algorithms is illustrated by synthesis of the control law for a local regulator, which provides the desired coefficients for the characteristic equations for separate orders of movement by the manipulator.
Actuators are often assumed to be perfectly aligned when designing for a stable closed-loop system. In practice, small actuator misalignments can cause the system to perform poorly, or worse, become unstable. Conseque...
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Actuators are often assumed to be perfectly aligned when designing for a stable closed-loop system. In practice, small actuator misalignments can cause the system to perform poorly, or worse, become unstable. Consequently, adaptive observers can be introduced that build online estimates for the unknown misalignments and recover closed-loop stability. In this paper, the problem where the control axes are independently misaligned in three dimensions is considered. A study of the problem indicates a fundamental geometric difference between in-plane and out-of-plane misalignments. Accordingly, special attention is paid to the case where two axes are independently misaligned. New nonlinear adaptive observers are introduced for both the in-plane and out-of-plane problems that guarantee that the misalignment axis estimates remain unit vectors. Furthermore, a Lyapunov-like stability analysis is performed to show convergence of the misalignment estimates to their true values for a wide range of misalignment angles. In addition, a novel control system is developed for a representative dynamic system containing the aforementioned actuator misalignments that ensures perfect asymptotic tracking of prescribed reference trajectories. Also, an axis decoupling method is described that helps alleviate some of the inherent issues in the estimation problem. Detailed proofs and numerical simulations are presented to help illustrate the technical aspects of the work.
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