  Avian-informed drones feature morphing wing and tail surfaces, enhancing
agility and adaptability in flight. Despite their large potential, realising
their full capabilities remains challenging due to the lack of generalized
control strategies accommodating their large degrees of freedom and
cross-coupling effects between their control surfaces. Here we propose a new
body-rate controller for avian-informed drones that uses all available
actuators to control the motion of the drone. The method exhibits robustness
against physical perturbations, turbulent airflow, and even loss of certain
actuators mid-flight. Furthermore, wing and tail morphing is leveraged to
enhance energy efficiency at 8m/s, 10m/s and 12m/s using in-flight Bayesian
optimization. The resulting morphing configurations yield significant gains
across all three speeds of up to 11.5% compared to non-morphing configurations
and display a strong resemblance to avian flight at different speeds. This
research lays the groundwork for the development of autonomous avian-informed
drones that operate under diverse wind conditions, emphasizing the role of
morphing in improving energy efficiency.
