Example Of Multi-agent System Research Articles

Agent-Based System for Continuous Control and its Application to Activated Sludge Process

This paper presents a concept of architecture and ontology layouts for development of multiagent model-based predictive control systems. The presented architecture provides guidelines to simplify development of agent-based systems and improve its maintainability. The proposed multiagent system (MAS) layout is split into multiple subsystems that include agents dedicated to performing assigned tasks. MAS implementation was prepared which can use provided algorithms, actuators and can react to changes in its environment to reach the best available control quality. An example of MAS based on the proposed architecture is shown in application of dissolved oxygen (DO) concentration control in a laboratory activated sludge setup with biological reactor. For that application, MAS incorporates agent-based controllers from Boundary-Based Predictive Controllers (BBPC) family. Presented experiments prove flexibility, resilience and online reconfiguration ability of the proposed multiagent system.

A Unified Dissertation on Bearing Rigidity Theory

This work focuses on bearing rigidity theory, namely the branch of knowledge investigating the structural properties necessary for multi-element systems to preserve the inter-unit bearings under deformations. The contributions of this work are twofold. The first one consists in the development of a general framework for the statement of the principal definitions and properties of bearing rigidity. We show that this approach encompasses results existing in the literature, and also provides a systematic approach for studying bearing rigidity on any differential manifold in SE(3)^n, where n is the number of agents. The second contribution is the derivation of a general form of the rigidity matrix, a central construct in the study of rigidity theory. We provide a necessary and sufficient condition for the infinitesimal rigidity of a bearing framework as a property of the rank of the rigidity matrix. Finally, we present two examples of multi-agent systems not encountered in the literature and we study their rigidity properties using the developed methods.

Finite-time positiveness and distributed control of Lipschitz nonlinear multi-agent systems

The finite-time positiveness and distributed control problem is studied for a class of Lipschitz nonlinear multi-agent systems. The objective is to design a suitable distributed controller which makes the closed-loop multi-agent systems be positive and finite-time stabilizable and satisfy the given H∞ performance index. Sufficient conditions are initially established on the existence of the finite-time distributed controller by using proper multiple Lyapunov functions and the design criteria are presented in the form of linear matrix inequalities. Finally, an example of multi-agent systems with six agents is presented to illustrate the feasibility and validity of the proposed methods.

Support System for Trading in Exchange Market by Distributional Forecasting Model

A lot of work is devoted to formalizing and devising architectures for agents' cooperative behaviour, for coordinating the behaviour of individual agents within groups, as well as to designing agent societies using social laws. However, providing agents with abilities to automatically devise societies so as to form coherent emergent groups that coordinate their behaviour via social laws, is highly challenging. These systems are called self-organised. We are beginning to understand some of the ways in which self-organised agent systems can be devised. In this perspective, this paper provides several examples of multi-agent systems in which self-organisation, based on different mechanisms, is used to solve complex problems. Several criteria for comparison of self-organisation between the different applications are provided.

Robust Stability of Switched Nonlinear Systems With Switching Uncertainties

This technical note focuses on a class of switched nonlinear systems with unstable modes and switching uncertainties. Both prescribed switching instants and switching sequence of the nominal switching signal would change. Two novel indexes named time changing ratios and mode changing ratios are proposed, based on which several conditions that fully utilize the trade-off among stable and unstable modes are established to achieve the robust stability of the switched system. An example of multi-agent systems illustrates the efficiency of the new results.

On Finite-Time Stability of Cyclic Switched Nonlinear Systems

This technical note considers the global finite-time stability problem for a class of switched nonlinear systems with the cyclic switching sequence, dissipative or non-dissipative impulsive effects may appear at each switching instant, and each mode may or may not be finite-time stable individually. A new concept named cycle dwell time is proposed based on which two stability conditions are established. These conditions fully reveal the trade-off among each mode's dynamics, impulsive dynamics and initial conditions. An example of multi-agent systems illustrates the efficiency of the new results.

Consensus Tracking of Multiagent Systems with Time-Varying Reference State and Exogenous Disturbances

The tracking control of multiagent dynamical systems with exogenous disturbances is studied. A path following algorithm with a time-varying reference state is proposed, and the path tracking of multiagent systems with exogenous disturbance is analyzed. Under the influence of the disturbances, a disturbance observer is developed to estimate the exogenous disturbances. Asymptotical consensus of the multiagent systems with time-varying reference state and exogenous disturbances under the disturbance observers-based control (DOBC) can be achieved for fixed and switching topologies. Finally, by applying an example of multiagent systems with switching topologies and exogenous disturbances, the consensus tracking of multiagent systems with time-varying reference state is reached under the DOBC with the designed parameters.

Robust consensus of multi-agent systems with time-delays and exogenous disturbances

In this paper, the robust consensus of multi-agent dynamical systems with time-delays and exogenous disturbances is studied. A pinning control strategy is designed for a parts of agents of the multi-agent systems without disturbances, and this pinning control can bring multiple agents’ states to an expected consensus track. Under the effects of the disturbances, disturbance observers based control (DOBC) are developed for disturbances generated by an exogenous system to estimate the disturbances. Asymptotical consensus of the multi-agent systems with disturbances under the composite controller can be achieved for fixed and switching topologies. Finally, by applying an example of multi-agent systems with switching topologies and exogenous disturbances, the design of the parameters of DOBC are illuminated.

Trajectory Control of Scale-Free Dynamical Networks with Exogenous Disturbances

In this paper, the trajectory control of multi-agent dynamical systems with exogenous disturbances is studied. Suppose multiple agents composing of a scale-free network topology, the performance of rejecting disturbances for the low degree node and high degree node is analyzed. Firstly, the consensus of multi-agent systems without disturbances is studied by designing a pinning control strategy on a part of agents, where this pinning control can bring multiple agents' states to an expected consensus track. Then, the influence of the disturbances is considered by developing disturbance observers, and disturbance observers based control (DOBC) are developed for disturbances generated by an exogenous system to estimate the disturbances. Asymptotical consensus of the multi-agent systems with disturbances under the composite controller can be achieved for scale-free network topology. Finally, by analyzing examples of multi-agent systems with scale-free network topology and exogenous disturbances, the verities of the results are proved. Under the DOBC with the designed parameters, the trajectory convergence of multi-agent systems is researched by pinning two class of the nodes. We have found that it has more stronger robustness to exogenous disturbances for the high degree node pinned than that of the low degree node pinned.

Consensus of multiagent systems based on disturbance observer

The objectives of this work are the development and design of disturbance observers (DO’s) for a team of agents that accomplish consensus on agents’ states in the presence of exogenous disturbances. A pinning control strategy is designed for a part of agents of the multiagent systems without disturbances, and this pinning control can bring multiple agents’ states to reaching an expected consensus value. Under the effect of the disturbances, nonlinear disturbance observers are developed for disturbances generated by an exogenous system to estimate the disturbances. Asymptotical consensus of the multiagent systems with disturbances under the composite controller can be achieved. Finally, by applying an example of multiagent systems with switching topologies and exogenous disturbances, the design of the parameters of DO’s are illuminated.

Support System for Trading in Exchange Market by Distributional Forecasting Model

A lot of work is devoted to formalizing and devising architectures for agents' cooperative behaviour, for coordinating the behaviour of individual agents within groups, as well as to designing agent societies using social laws. However, providing agents with abilities to automatically devise societies so as to form coherent emergent groups that coordinate their behaviour via social laws, is highly challenging. These systems are called self-organised. We are beginning to understand some of the ways in which self-organised agent systems can be devised. In this perspective, this paper provides several examples of multi-agent systems in which self-organisation, based on different mechanisms, is used to solve complex problems. Several criteria for comparison of self-organisation between the different applications are provided.

Cooperative Coevolutionary Adaptive Genetic Algorithm in Path Planning of Cooperative Multi-Mobile Robot Systems

In this paper, path planning of cooperative multi-mobile robot systems, an example of multi-agent systems, is discussed with the proposal of a novel Cooperative Coevolutionary Adaptive Genetic Algorithm (CCAGA). At the same time, for such genetic algorithms based path planning, a novel fixed-length decimal encoding mechanism for paths of each mobile robot is also proposed. Such cooperative coevolutionary adaptive genetic algorithm is suitable for parallel computation, which is convenient to solve complicated problems. Meanwhile, simulation results show that this algorithm has the property of robust convergency.

A Study on Dynamically Reconfigurable Robotic System. 18th Report. Evolutional Programming Method for Optimal Structurization of Distributed Autonomous Systems.

This paper discusses an optimization method of multi-agent system. A method for optimization called based on genetic algorithms is proposed and addressed. Evolutional programming can be applied to optimization of ill-structured systems such as multi-agent systems. As an example of multi-agent systems, the intelligence system of cellular robotic systems called CEBOT which has been previously studied by us is discussed. The intelligence system of CEBOT consists of many kinds of knowledge sources, which have simple levels of data and intelligence, together with some blackboards, which dynamically organize a hierarchical structure in order to optimize its own performance index. To realize optimal self-organization and self-evolution, evolutional programming is applied. The efficiency of the algorithm is shown by some simulations of self-organization and self-evolution of the intelligence system.