Group Of Mobile Autonomous Agents Research Articles

Comments on “Coordination of Groups of Mobile Autonomous Agents Using Nearest Neighbor Rules”

We clarify the relation between the model and the convergence results of Jadbabaie to those of Bertsekas We show that the update equations in Jadbabaie are a special case of those in Bertsekas Furthermore, the main convergence results in Sections II and III of Jadbabaie are essentially the same as those derived earlier in Bertsekas

Control of Multiagent Systems Using Linear Cyclic Pursuit With Heterogenous Controller Gains

In this paper, behavior of a group of autonomous mobile agents under cyclic pursuit is studied. Cyclic pursuit is a simple distributed control law, in which the agent i pursues agent i+1modn. The equations of motion are linear, with no kinematic constraints on motion. Behaviorally, they are identical but may have different controller gains. We generalize existing results in the literature, which consider only homogenous gains, to the case where controller gains are heterogenous. We show that, by selecting suitable controller gains, collective behavior of agents can be controlled significantly to obtain not only point convergence but also directed motion. In particular, we obtain analytical results that relate the controller gains to the direction of movement of the agents when the system is unstable. Invariance results with respect to the pursuit sequence are also proved. Finally, we also obtain some results that show some aspects of system behavior that is invariant with respect to finite switching of connections. Simulation experiments are given in support of the analytical results.

Virtual leader approach to coordinated control of multiple mobile agents with asymmetric interactions

This paper considers the collective dynamics of a group of mobile autonomous agents moving in Euclidean space with a virtual leader. We introduce a set of coordination control laws that enable the group to generate the desired stable flocking motion. The control laws are a combination of attractive/repulsive and alignment forces, and the control law acting on each agent relies on the state information of its flockmates and the external reference signal (or “virtual leader”). Using the control laws, all agent velocities asymptotically approach the desired velocity, collisions can be avoided between the agents, and the final tight formation minimizes all agent global potentials. Moreover, we show that the velocity of the center of mass either is equal to the desired velocity or exponentially converges to it. Furthermore, when the velocity damping is taken into account, we can appropriately modify the control laws to generate the same stable flocking motion. Subsequently, for the case where not all agents know the desired common velocity, we show that the desired flocking motion can still be guaranteed. Numerical simulations are worked out to illustrate our theoretical results. Additionally, we consider the effect of white noise on the collective dynamics of the group, and demonstrate numerically that the desired flocking motion can be kept for weak noise and, as the noise intensity increases, the flocking motion can be destroyed.

Comment on "Coordination of Groups of mobile autonomous agents using nearest neighbor Rules"

This note provides some corrections and generalizations to the aforementioned paper.

NEW FORMATION CONTROL DESIGNS WITH VIRTUAL LEADERS

Two formation control designs are presented for flocking of a group of mobile autonomous agents in an obstacle-free environment. Both control designs use virtual leader(s) and two different interactive forces. Virtual leader(s) are used to direct the group to track a desired path, as well as to ensure the group's cohesion, via the attractive force between agents and their virtual leader(s). The repulsive force between neighboring agents is used to avoid agent collisions. It is shown that the agents can achieve a desired formation and follow the desired path at the same velocity as the virtual leader's velocity. The absence of an attractive force between neighboring agents is a new feature of this approach, meant to help reduce sensing requirements in future designs that stress a reduced level of communication among agents.

Local Control Strategies for Groups of Mobile Autonomous Agents

The problem of achieving a specified formation among a group of mobile autonomous agents by distributed control is studied. If convergence to a point is feasible, then more general formations are achievable too, so the focus is on convergence to a point (the agreement problem). Three formation strategies are studied and convergence is proved under certain conditions. Also, motivated by the question of whether collisions occur, formation evolution is studied.

Correction to "Coordination of groups of mobile autonomous agents using nearest neighbor rules"

Correction to "Coordination of groups of mobile autonomous agents using nearest neighbor rules"

Coordination of groups of mobile autonomous agents using nearest neighbor rules

In a recent Physical Review Letters article, Vicsek et al. propose a simple but compelling discrete-time model of n autonomous agents (i.e., points or particles) all moving in the plane with the same speed but with different headings. Each agent's heading is updated using a local rule based on the average of its own heading plus the headings of its "neighbors." In their paper, Vicsek et al. provide simulation results which demonstrate that the nearest neighbor rule they are studying can cause all agents to eventually move in the same direction despite the absence of centralized coordination and despite the fact that each agent's set of nearest neighbors change with time as the system evolves. This paper provides a theoretical explanation for this observed behavior. In addition, convergence results are derived for several other similarly inspired models. The Vicsek model proves to be a graphic example of a switched linear system which is stable, but for which there does not exist a common quadratic Lyapunov function.