Finite-time-estimation-based surrounding control for a class of unknown nonlinear multi-agent systems

This paper deals with the surrounding control problem for a class of multi-agent systems. The followers and leaders have nonlinear heterogeneous dynamics, and the dynamics of the leaders are time-varying. In this work, it is supposed that dynamics of each follower consists of unknown parameters. For this reason, an adaptive law is used to adjust unknown parameters and an estimator to estimate the center of the leaders is used. Also, a new estimator is presented to estimate the summation of distances of the leaders from their geometric center. This estimation is used in the surrounding control protocol, especially when a sudden change happens in the movement of any leader. It is proved that the proposed estimator is stable in finite time sense. Some numerical examples to verify the the-oretical results are given.