Disturbance observer based consensus control for higher order multi-agent systems with mismatched uncertainties

A robust consensus controller is proposed for heterogeneous higher order nonlinear multi-agent systems (MAS), when the agent dynamics are potentially affected by mismatched uncertainties. A distributed consensus protocol based on finite time disturbance observer(FTDO) and sliding mode control is designed to realize the network consensus of higher order MAS. The control law can be used to solve the homogeneous as well as heterogeneous consensus problem simultaneously, where some agents have different nonlinear dynamics. FTDO is designed to estimate the uncertainties. The use of FTDO allows to neglect the effect of mismatched uncertainties during the sliding mode. For dismissing the chattering phenomenon and finite time convergence of the sliding surface, control law is designed using the super twisting algorithm. Finally numerical simulations are given to illustrate the validity of the proposed method.