Prescribed-Time Bipartite Formation Control for Heterogeneous UGVs–UAVs Systems With Improved Extended State Observers

Abstract

This article aims to address two challenging issues in heterogeneous systems composed of unmanned aerial vehicles (UAV) and unmanned ground vehicles (UGV): 1) compensating for system disturbances within prescribed-time and 2) maintain the non-zero speed of heterogeneous UAVs and UGVs system(HUUS) under complex constraints. The main difficulty lies in how to effectively compensate for external disturbances and internal unknown dynamics within prescribed-time while satisfying constraints, and simultaneously ensuring that the HUUS maintains non-zero velocity. To overcome these challenges, an improved prescribed-time extended state observer (PTESO) is proposed in this article. This observer can estimate uncertainties and disturbances, with the convergence time that can be pre-adjusted independently of initial conditions. By adopting an improved time-varying function as the PTESO gain, the transient peak phenomenon caused by excessive gain is avoided. To make the formation error converge within prescribed-time without violating error constraints, a time-varying barrier Lyapunov function is introduced in the control strategy, a prescribed-time bipartite formation control strategy based on the extended state observer is proposed. Furthermore, to address the problem that the speed tends to zero in the cross-dimensional model system, a comprehensive dynamic model of HUUS is derived, ensuring that the system velocity maintains the value. Compared with existing schemes, the proposed observer and controller demonstrate faster and more stable convergence performance. Finally, the effectiveness of the designed method is verified through simulation examples, proving the significant improvement in robustness and dynamic response capability of HUUS.