Vocalics in Human-Drone Interaction

TL;DR

The consequential sound during the flight of a quadrotor is utilized and modified to carry acoustic information while maintaining the visually perceived flight characteristics, contributing to human-drone interaction through onboard means.

Abstract

As the presence of flying robots continues to grow in both commercial and private sectors, it necessitates an understanding of appropriate methods for nonverbal interaction with humans. While visual cues, such as gestures incorporated into trajectories, are more apparent and thoroughly researched, acoustic cues have remained unexplored, despite their potential to enhance human-drone interaction. Given that additional audiovisual and sensory equipment is not always desired or practicable, and flight noise often masks potential acoustic communication in rotary-wing drones, such as through a loudspeaker, the rotors themselves offer potential for nonverbal communication. In this paper, quadrotor trajectories are augmented by acoustic information that does not visually affect the flight, but adds audible information that significantly facilitates distinctiveness. A user study (N=192) demonstrates that sonically augmenting the trajectories of two aerial gestures makes them more easily distinguishable. This enhancement contributes to human-drone interaction through onboard means, particularly in situations where the human cannot see or look at the drone.

Figures (3)

• Figure 1: Stills from trajectories communicating positive feedback \ref{['fig:stills_stft_positive']}, ordinary negative feedback \ref{['fig:stills_stft_negative_ord']}, and vocalics negative feedback \ref{['fig:stills_stft_negative_voc']} including relevant sections of the *stft of their microphone recordings. The drone's movement is visually emphasized through illustrated traces. Since the rotors have two blades, the measured frequency corresponds to twice the rotor speed.
• Figure 2: Relevant reference and tracked parameters of the three trajectories: The height $z$ for the positive feedback trajectory \ref{['fig:coords_positive']}, and the drone's yaw angle $\psi$ for both the ordinary negative feedback \ref{['fig:coords_negative_ord']} and the vocalics negative feedback \ref{['fig:coords_negative_voc']} trajectories. The background represents the corresponding reference parameter, while the parameter tracked by the pose estimation system is shown in orange.
• Figure 3: The Bitcraze Crazyflie 2.1 development drone platform used for this user study, with its rotors mounted upside down to avoid obscuring the LEDs of the tracking marker.