Université de Fribourg

Accelerating consensus of self-driven swarm via adaptive speed

Zhang, Jue ; Zhao, Yang ; Tian, Baomei ; Peng, Liqian ; Zhang, Hai-Tao ; Wang, Bing-Hong ; Zhou, Tao

In: Physica A: Statistical Mechanics and its Applications, 2009, vol. 3888, no. 7, p. 1237-1242

In recent years, the well-developed Vicsek model has attracted more and more attention. Unfortunately, in-depth research on its convergence speed is not yet completed. In this paper, we investigate some key factors governing the convergence speed of the Vicsek model with the assistance of extensive numerical simulations. A significant phenomenon surfaces that the convergence time scales obeys a...

Université de Fribourg

Predictive protocol of flocks with small-world connection pattern

Zhang, Hai-Tao ; Chen, Michael Z. Q. ; Zhou, Tao

In: Physical Review E, 2009, vol. 79, no. 01, p. 016113

By introducing a predictive mechanism with small-world connections, we propose a new motion protocol for self-driven flocks. The small-world connections are implemented by randomly adding long-range interactions from the leader to a few distant agents, namely, pseudoleaders. The leader can directly affect the pseudoleaders, thereby influencing all the other agents through them efficiently....

Université de Fribourg

Improve consensus via decentralized predictive mechanisms

Zhang, Hai-Tao ; Chen, Michael ZhiQiang ; Zhou, Tao

In: EPL Europhysics Letters, 2009, vol. 86, p. 40011

For biogroups and groups of self-driven agents, making decisions often depends on interactions among group members. In this paper, we seek to understand the fundamental predictive mechanisms used by group members in order to perform such coordinated behaviors. In particular, we show that the future dynamics of each node in the network can be predicted solely using local information provided by...

Université de Fribourg

Consensus of self-driven agents with avoidance of collisions

Peng, Liqian ; Zhao, Yang ; Tian, Baomei ; Zhang, Jue ; Wang, Bing-Hong ; Zhang, Hai-Tao ; Zhou, Tao

In: Physical Review E, 2009, vol. 79, no. 2, p. 026113

In recent years, many efforts have been addressed on collision avoidance of collectively moving agents. In this paper, we propose a modified version of the Vicsek model with adaptive speed, which can guarantee the absence of collisions. However, this strategy leads to an aggregated state with slowly moving agents. We therefore further add a certain repulsion, which results in both faster...

Université de Fribourg

Ultrafast consensus via predictive mechanisms

Zhang, Hai-Tao ; Chen, Michael ZhiQiang ; Zhou, Tao ; Stan, Guy-Bart

In: EPL Europhysics Letters, 2008, vol. 83, no. 4, p. 40003

An important natural phenomenon surfaces that ultrafast consensus can be achieved by introducing predictive mechanisms. By predicting the dynamics of a network several steps ahead and using this information in the consensus protocol, it is shown that, without changing the topology of the network, drastic improvements can be achieved in terms of the speed of convergence towards consensus and of...

Université de Fribourg

Collective behavior coordination with predictive mechanisms

Zhang, Hai-Tao ; Chen, Michael ZhiQiang ; Stan, Guy-Bart ; Zhou, Tao ; Maciejowski, Jan M.

In: IEEE Circuits and Systems Magazine, 2008, vol. 6, no. 3, p. 67 - 85

In natural flocks/swarms, it is very appealing that low-level individual intelligence and communication can yield advanced coordinated collective behaviors such as congregation, synchronization and migration. In the past few years, the discovery of collective flocking behaviors has stimulated much interest in the study of the underlying organizing principles of abundant natural groups, which has...

Université de Fribourg

Singularities and symmetry breaking in swarms

Li, Wei ; Zhang, Hai-Tao ; Chen, Michael ZhiQiang ; Zhou, Tao

In: Physical Review E, 2008, vol. 77, no. 5, p. 021920

A large-scale system consisting of self-propelled particles, moving under the directional alignment rule (DAR), can often self-organize to an ordered state that emerges from an initially rotationally symmetric configuration. It is commonly accepted that the DAR, which leads to effective long-range interactions, is the underlying mechanism contributing to the collective motion. However, in this...