*Article* **A Multilevel Architecture for Autonomous UAVs**

**Luca Bigazzi, Michele Basso, Enrico Boni, Giacomo Innocenti and Massimiliano Pieraccini \***

Department of Information Engineering, University of Florence, Via Santa Marta 3, 50139 Firenze, Italy; luca.bigazzi@unifi.it (L.B.); michele.basso@unifi.it (M.B.); enrico.boni@unifi.it (E.B.); giacomo.innocenti@unifi.it (G.I.)

**\*** Correspondence: massimiliano.pieraccini@unifi.it

**Abstract:** In this paper, a multilevel architecture able to interface an on-board computer with a generic UAV flight controller and its radio receiver is proposed. The computer board exploits the same standard communication protocol of UAV flight controllers and can easily access additional data, such as: (i) inertial sensor measurements coming from a multi-sensor board; (ii) global navigation satellite system (GNSS) coordinates; (iii) streaming video from one or more cameras; and (iv) operator commands from the remote control. In specific operating scenarios, the proposed platform is able to act as a "cyber pilot" which replaces the role of a human UAV operator, thus simplifying the development of complex tasks such as those based on computer vision and artificial intelligence (AI) algorithms which are typically employed in autonomous flight operations.

**Keywords:** UAV; autonomous flight; indoor positioning; cyber pilot; sensor fusion
