Adaptive predefined-time path-following control for fixed-wing UAV formations with prescribed performance

This paper addresses the formation mission for multiple fixed-wing unmanned aerial vehicles (UAVs) in three-dimensional space with a two-layer guidance and control framework. Firstly, this framework includes a three-dimensional adaptive predefined-time line-of-sight guidance law, ensuring the rapid convergence of the path-following errors. Meanwhile, a predefined-time path parameter consensus protocol with a distributed observer is proposed to realize the consensus of path parameters under distributed communication conditions. Recognizing the deficiencies of existing approaches, such as reliance on initial conditions and challenges in parameter tuning, an innovative adaptive predefined-time prescribed-performance control law is put forward for the control layer. Then, this control law integrates adaptive estimators and input auxiliary systems, which can effectively tackle internal uncertainties and external disturbances while ensuring that tracking errors remain within prescribed performance bounds. Finally, the advantages of the framework are demonstrated by simulation cases, and it shows that the proposed framework can guarantee a fast, precise, and robust cooperative formation performance.