Research On Flcoking Motion Control And Its Performances

Recently, distributed coordination control of the scale networked swarm system has been a particularly active topic in intelligent system field. The effort has been inspired by common swarming phenomena existing in nature everywhere. The scale networked swarm system not only can describe and explain most of the coordinated behaviors and self-organization phenomena of biological swarms, but also has potential applications in engineering. Thus, it is signification to study the theory and applications of Large-scale swarm systems.In this dissertation, through understanding the emergent mechanism of biological swarm, the further investigations on flocking control and the relevant dynamic characteristic of swarm behavior will be given.Firstly, the history, the present status about the theory and applications research for swarm behavior are overviewed. Then, based on the strategy of combining artificial potential with velocity consensus, flocking control model based on virtual leaders which are chosen adaptively from the surrounding is built; the stability analysis for the fixed and switching swarm system are given; and the influence of local interior and exterior surrounding are discussed.After that, we extend or combine existing methods to obstacle avoidance and flocking control in complex environments; then, we produce an intelligent swarm by giving individual agents some limited memories, and further discuss the obstacle avoidance and flocking control of the intelligent swarm. The result shows that the intelligent swarm can more efficient to achieve flocking motion in obstacle environment.A common assumption in distributed coordination control problems is the connectedness of the underlying network. Further research is discussed in this dissertation. At first, we analyze the essential of connectivity maintenance. Then, two distributed control strategies for connectivity maintenance are proposed. At last, two kind of systems with arbitrary initial states are analyzed, i.e., connected system and disconnected system. Flocking motion with connectivity maintenance can be achieved for each of them. It is proved that flocking problem can be solved under a more relaxed condition. Time-delay is ubiquitous in network system. For flocking behavior with an active leader, we discuss the stability of flocking motion with time delay. At first, we adopt a frequency-domain approach to this problem and discuss the stability of system with fixed time delay and time-varying delay. We derive sufficient conditions for the system under the same communication delays. Then, the stability of flocking motion with multiple time-delay is discussed with a frequency-domain approach that needs no derivative of time. A more relax convergence condition is obtained. Moreover, we further discuss the stability of uncertain systems with multiple time delays and perturbations by employing a linear matrix inequality method, and obtain the stability condition. At last tracing error is estimated by Lyapunov method, the time- delay influence on tracing error is discussed.The strategy of information feedback is efficient to improve the performance of system. Two strategies of information feedback from followers to the leader are introduced to the flocking motion; the robustness and tolerance of the proposed method are studied. The leader tracks a pre-defined trajectory and at the same time the leader uses the feedback information from followers to the leader to modify its motion .The advantage of this control scheme is that it reduces the tracking errors and improves the robustness of the team cohesion to followers' faults.At last, for the limition of the swarm model based on minimal circumcircle method, we extend the model to n-dimensional spaces; study the aggregating swarm behavior and flocking behavior; and analysis the stability of system.