In this paper, we consider the distributed adaptive optimization problem for nonlinear multi-agent systems (MASs) with unmatched uncertainties under a dynamic event-triggered mechanism (DETM). Unlike the existing dist...
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In this paper, we consider the distributed adaptive optimization problem for nonlinear multi-agent systems (MASs) with unmatched uncertainties under a dynamic event-triggered mechanism (DETM). Unlike the existing distributed optimization results that focus on the linear MASs under static or simple event-triggered communication, more general nonlinear MASs with unmatched uncertainties are considered in this paper, which makes the design of the distributed optimization strategy challenging. To solve this problem, a distributed adaptive optimization algorithm based on the dynamic eventtriggered mechanism is first proposed for first-order uncertain nonlinear MASs, which could provide a dynamic agent interaction-based adaptive event sampling. Based on this, a DETM-based distributed adaptive optimization algorithm is designed for high-order uncertain nonlinear MASs by employing the backstepping technique. Specifically, by introducing a high-order filter, an improved distributed optimization algorithm is further proposed, to ensure the existence of high-order derivatives of the local reference, making the application of the backstepping technique easy. Ultimately, a simulation example with comparisons is provided to show the efficacy of the developed algorithm. (c) 2025 Published by Elsevier Ltd.
Battery energy storage systems (BESSs) are critical components of microgrids. In this paper, we consider the dynamics of discharging batteries and propose a model for making a trade-off between balancing the state- of...
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Battery energy storage systems (BESSs) are critical components of microgrids. In this paper, we consider the dynamics of discharging batteries and propose a model for making a trade-off between balancing the state- of-charge (SoC) of battery units in a networked BESS and strategic usage of these battery units. To realize such a trade-off, we formulate an optimization problem that takes the total discharging power requirement and the limitations on individual battery units into account. The dynamics of SoC rely on the solution to the optimization problem. Furthermore, we reformulate the optimization problem in a distributed manner, employing estimators for certain global variables, and analyze the gap between the optimum with global information and the optimum with estimation in the steady state. Our simulation results verify that the trade-off between SoC balancing and strategic usage of battery units can be adjusted by tuning the weighting parameters in the optimization problems.
This study investigated the distributed optimization problem of multi-agent systems (MASs). The aim was to design optimization algorithms for two cases where the cost function was time-invariant and time-varying to al...
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This study investigated the distributed optimization problem of multi-agent systems (MASs). The aim was to design optimization algorithms for two cases where the cost function was time-invariant and time-varying to allow the system to reach the global optimum. First, a zero-gradient-sum (ZGS) distributed optimization algorithm based on second-order Hessian matrix information was designed to solve the time-invariant cost function optimization problem and allow the system to converge to the optimal state quickly in a fixed-time. Second, considering the case of a time-varying cost function, a distributed optimization algorithm based on a prediction-correction structure was designed by improving the above algorithm. This algorithm allows a system to converge to an optimal trajectory within a fixed-time. Finally, simulations were conducted to demonstrate the effectiveness of the control algorithms.
Autonomous aerial vehicles (AAV)-enabled IoT networks have shown promising potential in a range of novel applications and service scenarios, such as extending the network coverage, extending the battery lifetime of Io...
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Autonomous aerial vehicles (AAV)-enabled IoT networks have shown promising potential in a range of novel applications and service scenarios, such as extending the network coverage, extending the battery lifetime of IoT networks, and also supporting temporary data collecting and processing needs in various emergency situations. This article studies a federated edge intelligence (FEI) network based on the data collected and uploaded by a AAV-enabled IoT network. More specifically, a set of AAVs has periodically collected and uploaded the data generated by an IoT network to a set of edge servers. Edge servers will then collaboratively construct shared models based on the uploaded datasets. The data uploading performance of a AAV-enabled IoT network and the computational capacity of edge servers are entangled with each other in influencing the overall model training process. We propose a new framework called AAV-enabled IoT network for FEI (U-FEI). This framework enables edge servers to assess how many data samples need to be collected based on the energy costs of the AAV-enabled IoT network. It also considers the local data processing capacity of the edge servers. As a result, the edge servers can request just the right amount of data from the AAVs, which is enough to train a satisfactory model. We evaluate the energy cost for data uploading of AAVs when the data can be uploaded from two different types of frequencies: 1) licensed bands (e.g., using 5G) and 2) unlicensed bands (e.g., using Wi-Fi, ZigBee, or 5G NR-U). We prove that the cost minimization problem of the entire AAV-enabled IoT network is separable and can be divided into a set of subproblems, each of which can be solved by an individual edge server. We also introduce a mapping function to quantify the computational load of edge servers under the combinations of three key parameters: 1) size of the dataset;2) local batch size;and 3) number of local training passes. Finally, we adopt an alternative direction
This paper investigates the participation in grid services of large-scale storage devices aggregated as a virtual storage plant (VSP). A distributed optimization framework is developed to enable highly autonomous oper...
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This paper investigates the participation in grid services of large-scale storage devices aggregated as a virtual storage plant (VSP). A distributed optimization framework is developed to enable highly autonomous operation of the VSP for simultaneous provisions of the reserve service and voltage regulation of the local distribution network. A hardware-in-the-loop (HIL) testbed with real storage assets and realistic communication environment is established based on a transnational cooperation across multiple laboratories. Implementation details are provided with an emphasis on the forced-synchronized communication. The experimental results demonstrate the benefits and limitations of such distributed coordination for geographically dispersed storage devices over the cyber-physical networks, where the collected data is used to provide domain knowledge to improve the control design. This obtains important insights on the implementations of similar schemes in future power networks.
The integration of a large number of distributed resources into an active distribution network presents significant challenges, including high control dimensionality, strong output uncertainty, and low utilization of ...
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The integration of a large number of distributed resources into an active distribution network presents significant challenges, including high control dimensionality, strong output uncertainty, and low utilization of renewable energy. This paper introduces a distributed optimization strategy for networked microgrids based on network partitioning to alleviate the computational burden, reduce operating costs, and enhance the utilization of renewable energy. The active distribution network is partitioned into networked microgrids, and a two-layer distributed optimization model is developed for their management. The first layer focuses on intra-day distributed optimal dispatch, balancing power and load by managing various flexible resources and the exchange power between virtual microgrids. The second layer, real-time distributed power tracking optimization, coordinates flexible resources within virtual microgrids to mitigate photovoltaic power fluctuations and track intra-day dispatch instructions. Simulation results demonstrate that the proposed network partitioning method reduces dispatch costs by 5.3 % and increases the utilization of distributed PV by 3 %, compared to the NP method that only considering modularity. Moreover, calculation times for intra-day dispatch and real-time power tracking are reduced by approximately 26 % and 50 %, respectively, compared to centralized control.
Based on the so-called lazy gradient information, this note proposes two communication-reduced distributed optimization algorithms over undirected multi-agent networks. The lazy gradients refer to some gradients that ...
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Based on the so-called lazy gradient information, this note proposes two communication-reduced distributed optimization algorithms over undirected multi-agent networks. The lazy gradients refer to some gradients that do not change much in the past iterations and thus may not be distributed among agents which correspondingly reduces the communication load in the networks. For both the deterministic and the stochastic frameworks, the asymptotic properties of the distributed optimization algorithms are established. Compared with the existing literature using the lazy gradient information, the proposed algorithms in the paper are fully distributed and more suitable for the situation of decentralized multi-agent networks. The effectiveness of the proposed algorithms is also testified through numerical simulations.
Compositional data have been widely used in various fields to analyze parts of a whole, providing insights into proportional relationships. With the increasing availability of extraordinarily large compositional datas...
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Compositional data have been widely used in various fields to analyze parts of a whole, providing insights into proportional relationships. With the increasing availability of extraordinarily large compositional datasets, addressing the challenges of distributed statistical methodologies and computations has become essential in the era of big data. This paper focuses on the optimization methodology and practical application of the distributed sparse penalized linear log- contrast model for massive compositional data, specifically in the context of medical insurance reimbursement ratio prediction. We propose two distributed optimization techniques tailored for centralized and decentralized topologies to effectively tackle the constrained convex optimization problems that arise in this application. Our algorithms are rooted in the frameworks of the alternating direction method of multipliers and the coordinate descent method of multipliers, making them available for distributed data scenarios. Notably, in the decentralized topology, we introduce a distributed coordinate-wise descent algorithm that employs a group alternating direction method of multipliers to achieve efficient distributed regularized estimation. We rigorously present convergence analysis for our decentralized algorithm, ensuring its reliability for practical applications. Through numerical experiments on both simulated datasets and a real- world medical insurance dataset, we evaluate the performance of our proposed algorithms.
This article is intended to tackle the optimization problems for continuous-time first-order and second-order multi-agent systems (MASs) operating over matrix-weighted networks. A matrix-weighted network serves as a p...
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This article is intended to tackle the optimization problems for continuous-time first-order and second-order multi-agent systems (MASs) operating over matrix-weighted networks. A matrix-weighted network serves as a powerful framework to model the interdependence among agents' multidimensional states, providing an effective approach to analyze smart grids, intelligent transportation systems, and so forth. Our optimization objective is to facilitate the convergence of all agents toward the optimal value of a global cost function, which is formed by a sum of local cost functions. To achieve this goal, distributed optimization algorithms based on Hessian matrix and gradient information are constructed. Additionally, an edge-based event-triggered mechanism is utilized to avoid communicating with all neighbors at the time of event triggering. It is proved that this mechanism theoretically excludes Zeno behavior. The results show that the proposed algorithms ensure that the agents can achieve the optimization goal while reducing energy consumption. Finally, an application is presented to substantiate the theoretical results.
The implementation of distributed optimization, depending on the application, imposes escalating demands on communication and computational synchronization, with the general desire for the robust performance in the fa...
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The implementation of distributed optimization, depending on the application, imposes escalating demands on communication and computational synchronization, with the general desire for the robust performance in the face of computationally slow agents and the avoidance of unnecessary communication. In this article, we propose a distributed algorithm with asynchronous computation and event-triggered communication (DAAET) that enables the nodes to flexibly determine their update and information transmission instants. DAAET achieves compatibility with nodes operating at varying computation frequencies and accomplishes a reduction in both wall time and communication costs. Meanwhile, this article proposes a model reconstruction technique to handle disconnectivity arising from the asynchronous implementation of the event-triggered mechanism. Theoretical analysis demonstrates the algorithm's linear convergence to the global optimum under relaxed conditions. The effectiveness and advantages of our approach are demonstrated through a set of examples, showcasing its potential for practical applications.
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