Delay-tolerant adaptive robust control for unmanned aerial system

Abstract

The presence of system uncertainties and time-delay in the control loop can create off-nominal flying conditions and limit the performance of the flight controller. To provide on-board control resilience and enhanced stability margins for safe autonomous flight, it is vital to account for the parameter variations, input time-delay, and time-varying uncertain nonlinearities/disturbances, simultaneously, during the control design in a rigorous theoretical manner. To address the above challenging problem, this paper proposes a high-performance predictor adaptive robust control (PARC) design methodology for tracking the desired trajectory. The controller guarantees semi-global, exponential convergence and final tracking accuracy that is proportional to the time-delay, disturbance bounds, and con troller gain. The controller effectiveness is illustrated on the simulation of a flight control example with the longitudinal dynamics of a jet transport aircraft and compared with the baseline adaptive robust controller.