Decentralized finite-time sliding mode estimators with applications to formation tracking

In this paper, a simple but efficient framework is proposed to achieve finite-time decentralized formation tracking of multiple autonomous vehicles with the introduction of decentralized sliding mode estimators. First, we propose and study both first-order and second-order decentralized sliding mode estimators. In particular, we show that the proposed first-order decentralized sliding mode estimator can guarantee accurate position estimation in finite time and the proposed second-order decentralized sliding mode estimator can guarantee accurate position and velocity estimation in finite time. Then the decentralized sliding mode estimators are employed to achieve decentralized formation tracking of multiple autonomous vehicles. In particular, it is shown that formation tracking can be achieved for systems with both single-integrator kinematics and double-integrator dynamics in finite time. Because accurate estimation can be achieved in finite time by using the decentralized sliding mode estimators, many formation tracking/flying scenarios can be easily decoupled into two subtasks, that is, decentralized sliding mode estimation and vehicle desired state tracking, without imposing a stringent condition on the information flow.