Optimized L₁ adaptive controller for trajectory tracking of an indoor quadrotor

This paper proposes a systematic analysis and synthesis method for the optimal design of filters for L₁ adaptive output feedback controllers. In the L1 adaptive feedback structure, the low-pass filter is the key to the tradeoff between the performance and robustness of the closed-loop system. Although the filter design for the L₁ adaptive architecture has been studied in previous papers, the need for a numerically tractable synthesis method is yet to be fulfilled. In this paper, the L₁ adaptive controller with an optimized filter is used for precision trajectory tracking control of a small quadrotor (Crazyflie) in an experimental setup. The controller demonstrates robustness to time delay, noise, disturbances, radio transmission, and uncertainties in the modeling of quadrotor.