This paper proposes a novel two-layer distributed control scheme for global cooperative output regulation for a class of nonlinear multi-agent systems. The concerned systems are (i) heterogeneous and uncertain, (ii) w...
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ISBN:
(纸本)9781479978878
This paper proposes a novel two-layer distributed control scheme for global cooperative output regulation for a class of nonlinear multi-agent systems. The concerned systems are (i) heterogeneous and uncertain, (ii) with unknown local control directions, and (iii) under a directed communication graph. To cope with the problem, a two-layer control structure is first configured and distributed and decentralized laws are developed for the layers respectively. Then we demonstrate that combination of the control laws may lead to an effective solution to the cooperative output regulation problem. Finally, an illustrative example is given to show the effectiveness of the proposed control algorithm.
Bi-geometric transparent composite models (BGTCM) are used to model distributions of transform coefficients in HEVC (High efficiency video coding). Both Kullback-Leibler divergence and χ~2 test show that, for both or...
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ISBN:
(纸本)9781479983407
Bi-geometric transparent composite models (BGTCM) are used to model distributions of transform coefficients in HEVC (High efficiency video coding). Both Kullback-Leibler divergence and χ~2 test show that, for both original and quantized transform coefficients in HEVC, BGTCMs provide better modelling performance than popular Laplacian and Cauchy models. Based on BGTCMs, a rate control algorithm is proposed for HEVC. Experimental results using the HEVC reference software show that the proposed algorithm achieves better performance in constant-bit-rate control than previous rate control algorithms based on Laplacian models.
This paper presents a Lyapunov-based method for verification and synthesis of decentralized chassis control systems. The method provides performance guarantees without exposing the control algorithms of each agent. We...
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ISBN:
(纸本)9781509045839
This paper presents a Lyapunov-based method for verification and synthesis of decentralized chassis control systems. The method provides performance guarantees without exposing the control algorithms of each agent. We use a Lyapunov derivative condition to guarantee stability and set invariance of the closed-loop system. Agents are asked to exchange polynomials that represent the influence of the control actions on the system dynamics, while the control algorithms are kept secret. Dual decomposition is used to ensure that the solution converges and is equivalent to that of a centralized solution.
Three-phase Dual Active Bridge (DAB) Y : Y/Δ composite topology offers advantage of nearly sinusoidal converter-currents without pulse-width modulation, which can be utilized for D-Q mode control implementation. D-Q ...
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ISBN:
(纸本)9781479903375
Three-phase Dual Active Bridge (DAB) Y : Y/Δ composite topology offers advantage of nearly sinusoidal converter-currents without pulse-width modulation, which can be utilized for D-Q mode control implementation. D-Q control is smooth and regulates power-factor of DAB which ensures zero voltage switching (ZVS) operation of the DAB converter at wide-range loading conditions. A practical DAB high-frequency transformer has certain limitations like small leakage-inductance, limited magnetizing-inductance and unwanted parasitic-capacitance's which distort the primary-side currents at the rated high-voltage because primary inter-turn capacitance is high in per-unit for a real 100kW transformer-design. This problem can be solved by using secondary currents and estimated magnetizing current to emulate primary-currents for D-Q control. Parasitic are introduced in the LV TIPS set-up by adding lumped elements to emulate real HV-transformer with objective to test the controls in worst case scenario. This paper proposes the solutions for some of the practical implementation problems of the control algorithm for the DAB.
The Shaped Metal Deposition (SMD) is a novel technique for rapid manufacturing of mechanical parts. It uses a robotic arm and a Tungsten Inert Gas (TIG) arc welding system in order to obtain the desired component fina...
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ISBN:
(纸本)9781617387197
The Shaped Metal Deposition (SMD) is a novel technique for rapid manufacturing of mechanical parts. It uses a robotic arm and a Tungsten Inert Gas (TIG) arc welding system in order to obtain the desired component final shape adding progressively the needed material. Actually this is the first work, as far as we know, concerning an automatic control system on such a process. After a depth study of several aspects of the process, the fundamental key parameters have been identified. A simplified version of the SMD plant has been equipped both to study and to develop different control algorithms. In order to monitor and to investigate the process several types of sensors have been used during several simpler experimental tests. The experience acquired allowed to develop several basic control laws, so that a closed loop controller has been implemented. This controller takes and maintains the process around a stable working condition, so that the final process results totally automatic.
To meet the requirement of high reliability, practicability and stability in low cost, a multi-objective control algorithm is proposed based on split-capacitor-type three-phase four-wire distribution static generator....
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ISBN:
(纸本)9781479917631
To meet the requirement of high reliability, practicability and stability in low cost, a multi-objective control algorithm is proposed based on split-capacitor-type three-phase four-wire distribution static generator. The control algorithm is implemented on improved i_p-i_q method and certain equivalent triangle conversion;then the six target components including negative, zero and base positive sequence reactive current, negative and zero sequence active current, harmonic current, are simultaneously detected;PI control and triangle wave modulating technique respectively is applied in DC side capacitor voltage stabilizing and reference current tracking. The control algorithm can achieve dispersion compensation or any composite compensation of six target components. A multi-objective distribution static generator model is simulated on PSCAD/EMTDC, while a prototype is built on the experimental platform based on FPGA+DSP, which validate the effectiveness of the proposed control strategy.
Controls in power systems such as national utility grids, microgrids, and shipboard electrical infrastructures are evolving and conventional testbeds are inadequately outfitted for effective design, development, and t...
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ISBN:
(纸本)9781479913022
Controls in power systems such as national utility grids, microgrids, and shipboard electrical infrastructures are evolving and conventional testbeds are inadequately outfitted for effective design, development, and testing. In particular, conventional power system control testbeds typically lack appropriate computational and data communication tools to quickly and accurately represent advanced control architectures. In this paper, we discuss experiences with a distributed control testbed by incorporating general purpose computational platforms and a more extensive data communications infrastructure. These components enhance the testbed by providing access to key technologies expected to be prevalent in emerging power systems and also simplify the implementation of sophisticated control architectures. Evaluation of the improved capabilities of the testbed is provided through two studies. The first explores the control capabilities for a shipboard power system through the use of hierarchical and distributed control structures. The second investigates the effect of data communication latencies on a control algorithm through a test case involving synchronization of multiple generators.
We describe a parallel fast multipole method (FMM) for highly nonuniform distributions of particles. We employ both distributed memory parallelism (via MPI) and shared memory parallelism (via OpenMP and GPU accelerati...
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We describe a parallel fast multipole method (FMM) for highly nonuniform distributions of particles. We employ both distributed memory parallelism (via MPI) and shared memory parallelism (via OpenMP and GPU acceleration) to rapidly evaluate two-body nonoscillatory potentials in three dimensions on heterogeneous high performance computing architectures. We have performed scalability tests with up to 30 billion particles on 196,608 cores on the AMD/CRAY-based Jaguar system at ORNL. On a GPU-enabled system (NSF's Keeneland at Georgia Tech/ORNL), we observed 30x speedup over a single core CPU and 7x speedup over a multicore CPU implementation. By combining GPUs with MPI, we achieve less than 10 ns/particle and six digits of accuracy for a run with 48 million nonuniformly distributed particles on 192 GPUs.
We illustrate a multiscale model for social dynamics of large groups. The examples we have in mind span both cases of real dynamics, such as crowd in motion, but also virtual dynamics, such as opinion formation in soc...
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ISBN:
(纸本)9781479932757
We illustrate a multiscale model for social dynamics of large groups. The examples we have in mind span both cases of real dynamics, such as crowd in motion, but also virtual dynamics, such as opinion formation in social networks. The model is based on a measure theoretic approach, where the space of Radon measure with finite mass is endowed with a generalized Wasserstein metric. The latter allows the comparison of measures with different mass, thus including models in which the total mass of the measure may vary in time. The control paradigm is a centralized sparse control algorithm: A centralized controller is free to act on any agent of the system, but with the constraint of acting only on a small number of agents at the same time. We show some results in the completely discrete case and some new approach to deal with the continuum and mixed cases.
This paper proposes a novel switched second order sliding mode (S-SOSM) control strategy in a partial information setting, i.e., when only the sliding variable is accessible for measurements. The S-SOSM setting can de...
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ISBN:
(纸本)9781612848006
This paper proposes a novel switched second order sliding mode (S-SOSM) control strategy in a partial information setting, i.e., when only the sliding variable is accessible for measurements. The S-SOSM setting can deal with systems characterised by different levels of uncertainties associated with different regions of the state space and to accommodate different control objectives in the different regions by switching among appropriate SOSM controllers. The proposed approach stems from an ad hoc extension of a SOSM control algorithm which was introduced to cope with state-dependent uncertainties, and it is shown to ensure global finite-time convergence to the origin of the closed-loop system trajectory.
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