Robust Auto-Tuning Control of a Delivery Quadcopter with Motor Faults, Mass and Inertia Estimation

Unstable position and attitude caused by severe motor faults and varying payloads complicates the design of a reliable flight controller for delivery quadcopters during last-mile deliveries. To ensure safe and efficient operation, a novel, robust and adaptive control strategy is employed using a two-stage recursive least squares based estimation, combined with an auto-tuning mixed-sensitivity H∞ controller. A numerical simulation demonstrates fast and accurate real-time estimation of actuator loss of effectiveness and changes in the mass and inertia due to payload pickup/drop-off during delivery missions. The combined and uneven effects of multiple faults with initial mass and inertia uncertainties are efficiently compensated by this novel fault tolerant flight control strategy. The controller also improves the rejection of these uncertainties during the transient stage before the convergence of the parameter estimation. The proposed approach maintains the operational reliability of delivery quadcopters under a range of challenging uneven faults and significant mass and inertia uncertainties.