Uncertainty-Observer-Based Dynamic Sliding Mode Formation Control for Multi-Agent Systems

For practical applications of multi-agent systems, agents could be continuously subject to external disturbances, which is likely to negatively affect their tracking performances. Furthermore, the unknown or inaccurate factors in system dynamics can also bring negative effects to a system’s performance. In this paper, an uncertainty-observer-based dynamic sliding mode control scheme is proposed to deal with time-varying formation control problems of second-order nonlinear multi-agent systems. An uncertainty observer is first implemented for each agent to estimate the combination of the agent’s external and internal uncertainties and its time derivative. An observer-based dynamic sliding mode formation control law is developed for a cluster of second-order nonlinear agents to achieve time-varying formation. Finally, a numerical simulation is provided to illustrate the validity of the proposed control approach.