Fixed-Time Formation Control of Multirobot Systems: Design and Experiments

• Published in: IEEE transactions on industrial electronics (1982) Vol. 66; no. 8; pp. 6292 - 6301
• Main Authors: Wang, Chunyan, Tnunay, Hilton, Zuo, Zongyu, Lennox, Barry, Ding, Zhengtao
• Format: Journal Article
• Language: English
• Published: New York IEEE 01.08.2019; The Institute of Electrical and Electronics Engineers, Inc. (IEEE)
• Subjects: Computer simulation; Consensus control; Control systems; Delay; Delay effects; Delays; fixed-time formation; formation control; Image processing; Initial conditions; input delay; Liapunov functions; Multi-agent systems; Multi-robot systems; Multiple robots; multirobot systems; Protocol (computers); Protocols; Robots; Settling; Task analysis; Topology; Upper bounds
• ISSN: 0278-0046; 1557-9948
• DOI: 10.1109/TIE.2018.2870409

Time delays exist in network-connected systems. Especially for vision-based multirobot systems, time delays are diverse and complicated due to the communication network, camera latency, image processing, etc. At the same time, many tasks, such as searching and rescue, have timing requirement. This paper focuses on fixed-time formation control of multirobot systems subject to delay constraints. First, predictor-based state transformation is employed for each robot to deal with the input delay, and the uncertain terms remained in the transformed systems are carefully considered. Then, a couple of nonlinear fixed-time formation protocols are proposed for the multirobot systems with respectively undirected and directed topology, and the corresponding settling time is derived by using the Lyapunov functions. In particular, the upper-bound estimation of the formation settling time is explicitly given irrelevant to the initial conditions. Finally, the protocols are validated through a numerical simulation example and then implemented on an E-puck robots platform. Both simulation and experimental results demonstrate the effectiveness of the proposed formation protocols.