Observer-based finite-time time-varying elliptical formation control of a group mobile mecanum-wheeled omnidirectional vehicles for collaborative wildfire monitoring

This article addresses the issue of collaborative wildfire monitoring using a group mobile mecanum-wheeled omnidirectional vehicles (MWOVs) affected by nonlinear uncertainties and external disturbances. By integrating finite-time extended state observers (FTESO) and backstepping nonsingular fast terminal sliding mode (BNFTSM) control method, an observer-based finite-time time-varying elliptical formation control scheme is proposed for a group of MWOVs tasked with monitoring the propagation of wildfires in an elliptical pattern. First, the FTESO is employed to estimate the unavailable velocity system states and the lumped disturbances. Then, a novel nonsingular fast terminal sliding surface, enhanced with an exponential term, is introduced to improve the convergence rate. Through the Lyapunov theorem, the convergence of position and velocity cooperative tracking errors to zero in fast finite-time is demonstrated. To showcase the effectiveness of the proposed control scheme, comparative simulation results are presented.