Fixed-Time Anti-Disturbance Average-Tracking for Multi-Agent Systems Without Velocity Measurements

In this paper,the authors tackle a fixed-time average-tracking problem for multi-agent systems which do not require velocity measurements and are affected by external mismatched and matched disturbances.The objective requires the considered agents with second-order dynamics to follow the average value of several time-varying reference signals,each of which is acquired by only one agent.First of all,the average value is estimated by using a novel distributed average estimator in a fixed time.Second,an original observer is created to provide estimated values in a fixed time for external mismatched and matched disturbances as well as unmeasured velocities of agents.Then,the authors propose a novel fixed-time anti-disturbance average-tracking protocol with the aid of the observer and a sliding mode surface.In the end,the feasibility of theoretical analysis is illustrated by some simulation experiments.