[신간의 별자리x] 우리/미술, 그리고 ‘슬픔의 박물관’

This paper reviews some main results and progress in distributed multi-agent coordination, focusing on papers published in major control systems and robotics journals since 2006. Distributed coordination of multiple vehicles, including unmanned aerial vehicles, unmanned ground vehicles, and unmanned underwater vehicles, has been a very active research subject studied extensively by the systems and control community. The recent results in this area are categorized into several directions, such as consensus, formation control, optimization, and estimation. After the review, a short discussion section is included to summarize the existing research and to propose several promising research directions along with some open problems that are deemed important for further investigations.

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An Overview of Recent Progress in the Study of Distributed Multi-Agent Coordination

This article reviews some main results and progress in distributed multi-agent coordination, focusing on papers published in major control systems and robotics journals since 2006. Distributed coordination of multiple vehicles, including unmanned aerial vehicles, unmanned ground vehicles and unmanned underwater vehicles, has been a very active research subject studied extensively by the systems and control community. The recent results in this area are categorized into several directions, such as consensus, formation control, optimization, task assignment, and estimation. After the review, a short discussion section is included to summarize the existing research and to propose several promising research directions along with some open problems that are deemed important for further investigations.

An Overview of Recent Progress in the Study of Distributed Multi-agent Coordination

This paper develops a sliding-mode control (SMC) approach for systems with mismatched uncertainties via a nonlinear disturbance observer (DOB). By designing a novel sliding surface based on the disturbance estimation, a DOB-based SMC method is developed in this paper to counteract the mismatched disturbance. The newly proposed method exhibits the following two attractive features. First, the switching gain is only required to be designed greater than the bound of the disturbance estimation error rather than that of the disturbance; thus, the chattering problem is substantially alleviated. Second, the proposed method retains its nominal performance, which means the proposed method acts the same as the baseline sliding-mode controller in the absence of uncertainties. Simulation results of both the numerical and application examples show that the proposed method exhibits much better control performance than the baseline SMC and the integral SMC (I-SMC) methods, such as reduced chattering and nominal performance recovery.

Sliding-Mode Control for Systems With Mismatched Uncertainties via a Disturbance Observer

Brief paper: On pinning synchronization of complex dynamical networks

Brief paper: On the V-stability of complex dynamical networks

This note addresses the problem of synchronized output regulation of linear networked system where all the nodes have their outputs track signals produced by the same exosystem and the state of exosystem is accessible only to leader nodes, while follower nodes regulate their outputs via a distributed synchronous protocol. This problem can be decoupled into two: one is the output regulation problem on the synchronous manifold and the other is the stability problem of synchronous manifold. The proposed synchronous protocol is independent of the network topology. The stability of synchronous manifold is analyzed through the permissible eigenvalue region and the requirements of information graph. Finally, a numerical example illustrates the efficacy of the presented results.

Synchronized Output Regulation of Linear Networked Systems

A class of networked multi-agent systems is studied in this study where each agent has an identical dynamics of a simple integrator and the topology of the connections is fixed. It is proved that, when there are saturation constraints, a general consensus protocol widely used in the literatures for this class of multi-agent systems remains valid. As an extension, a 'bang-bang' type of consensus protocol is proposed to achieve the finite-time consensus, which relaxes the previous undirected connection assumption.

Consensus problems for linear time-invariant multi-agent systems with saturation constraints

In this paper, we develop a simple algorithm to determine the required number of generating units of wind-turbine generator and photovoltaic array, and the associated storage capacity for stand-alone hybrid microgrid. The algorithm is based on the observation that the state of charge of battery should be periodically invariant. The optimal sizing of hybrid microgrid is given in the sense that the life cycle cost of system is minimized while the given load power demand can be satisfied without load rejection. We also report a case study to show the efficacy of the developed algorithm.

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A Simple Sizing Algorithm for Stand-Alone PV/Wind/Battery Hybrid Microgrids

This paper presents the general-weighted least-norm (GWLN) method for the control of redundant manipulators by a new concept of virtual joints, which consist of the performance function of subtasks. The GWLN method enables the redundant manipulator to perform multiple subtasks with the assumption that all the subtasks can be represented by the inequalities as the joint limits avoidance subtask. The number of subtasks to be coped with might be even larger than the number of joints if they do not happen simultaneously. The simulations in contrast to the traditional gradient projection method (GPM) and the recent directional GPM have been made to manifest the advantages of the proposed method. An experiment on the seven-degree-of-freedom redundant manipulator illustrates the good performance for tracking a given trajectory of end-effector position, while both guaranteeing the obstacle free and not violating the joint limits.

Ji Xiang

Papers

Brief paper: On the V-stability of complex dynamical networks

Synchronized Output Regulation of Linear Networked Systems

Consensus problems for linear time-invariant multi-agent systems with saturation constraints

A Simple Sizing Algorithm for Stand-Alone PV/Wind/Battery Hybrid Microgrids

General-Weighted Least-Norm Control for Redundant Manipulators