连通性保持下的多机器人系统分布式群集控制

Decentralized flocking of multi-robot systems with connectivity maintenance

中文关键词  多机器人系统  分布式控制  群集  连通性保持  有向图

英文关键词  multi-robot systems  decentralized control  flocking  connectivity maintenance  directed graphs

中文摘要

      多机器人系统群集控制中的连通性保持对于系统的稳定性和状态收敛的快速性具有重要影响. 本文在初始通信网络拓扑为强连通非平衡图的条件下, 研究具有非完整约束运动学模型的多轮式移动机器人系统群集运动中的连通性保持控制问题. 首先, 构造了一类新颖的光滑有界的人工势场函数, 该类函数可以同时满足连通性保持、碰撞规避和相对距离镇定等任务需求. 进一步, 将基于势函数梯度的控制策略与一致性控制机制有机结合, 在系统中存在和不存在领航者的条件下, 分别设计出一类具有连通性保持功能的光滑有界的分布式群集控制协议, 不仅可有效避免不连续/非光滑控制器所固有的抖振现象以及执行器饱和问题, 而且实现了将传统群集控制中的连通性保持算法从个体运动模型和系统通信拓扑类型两个方面同时加以拓展. 最后, 仿真结果和实验结果验证了本文所提出的光滑有界群集控制算法的有效性.

英文摘要

      Connectivity maintenance of flocking is vital for stability and fast state convergence of the entire multirobot system. To this end, the problem of flocking of multiple nonholonomic wheeled mobile robots with connectivity maintenance on directed communication graphs is investigated, provided that the initial network is strongly connected but not balanced. First, a new class of smooth and bounded artificial potential fields is developed to satisfy the requirements of connectivity maintenance, collision avoidance and distance stabilization, simultaneously. Furthermore, by combining potentialbased gradient control techniques and the consensus seeking control schemes, we propose a set of smooth and bounded control protocols for leaderless flocking or flocking with local leader-follower with connectivity maintenance. Those control protocols not only avoids the chattering and saturation caused by the discontinuous/nonsmooth and unbounded flocking algorithms, but also extend the traditional connectivity-preserving flocking algorithms for both the individual motion model and the network topology types. Finally, nontrivial simulations and experiments are performed to validate the effectiveness of the proposed smooth and bounded control strategies.