High-precision prescribed-time path following for quadrotor

Abstract

A high-precision prescribed-time guidance law is developed for a quadrotor to accomplish precise path following at predesigned time T. Firstly, a new control structure is proposed for a quadrotor to perform fixed-velocity back-to-turn flying mode by introducing four controllers, which can realize a non-sideslip and bank-to-turn flight scheme just like a fixed-wing unmanned aerial vehicle. Then, prescribed-time guidance law is presented based on fixed-velocity back-to-turn flying mode via combining sliding mode control with a compensation function (Formula presented.) to improve tracking precision of conventional methods. Compensation function (Formula presented.) is designed to make state error achieve convergence at prescribed time exactly. Meanwhile, global sliding mode is established to enhance robustness of the system. Then, the stability and characteristic of prescribed-time convergence are proved strictly. Finally, simulations with a 6-degree-of-freedom quadrotor model are carried out to demonstrate the effectiveness and superiority of prescribed-time guidance law by comparing with traditional guidance law.