Comparison of Tactile Signals for Collision Avoidance on Unmanned Aerial Vehicles Stefan Spiss 1 , Yeongmi Kim 2 , Simon Haller 1 , and Matthias Harders 1 1 Department of Computer Science, University of Innsbruck, Austria 2 Department of Mechatronics, MCI, Austria stefan.spiss@student.uibk.ac.at, matthias.harders@uibk.ac.at Abstract. Our recent work focused on the development of intuitive user interfaces for the control of unmanned aerial vehicles, such as quad- copters. Next to intuitive gesture control, a key challenge with remotely operated quadcopters is the display of information about the aircraft sur- roundings. To this end, we examined the use of rendering tactile stimuli to warn about nearby obstacles. Directional information and distance is encoded via vibrotactile signals from rotating mass motors. Three dif- ferent methods of delivering the tactile feedback were tested in a user study. Results show that even though participants guided the quadcopter through a maze by tactile stimuli alone, they were, on average, able to avoid full crashes. Further, we found that using sequential signals to in- dicate obstacles lead to significantly increased numbers of wall contacts. Keywords: quadcopter, haptic, vibrotactile feedback, user interface 1 Introduction Unmanned aerial vehicles (UAVs) are flight systems that do not carry a pilot, but are, in general, remotely controlled. Due to this, they are often smaller and more efficient. Also, no crew is put in possible danger during flight [1]. A key challenge for an operator is the loss of situational awareness of and knowledge about the surroundings of the aircraft. In most cases, UAVs are equipped with forward facing cameras to provide a video stream to the ground station. However, information about obstacles not in camera view is not readily available, which can be a problem in difficult environments, for instance in indoor rescue opera- tions. Especially for quadcopters this is of concern due to their omnidirectional maneuverability. In related work, the use of tactile feedback has been examined for cock- pits [10] as well as for waypoint navigation of pedestrians, helicopter pilots, and boat drivers [8]. Using a vibrotactile waist belt led to performance improvement after only short familiarization. A similar application area is the use of tactile feedback for collision prevention and navigation in cars, e.g. [6,3]. Moreover, related systems have also been employed as electrical travel aids for visually im- paired persons to warn about obstacles [4, 5]. Generally, designs often take the form of torso [9] or belt-type displays [7]. The work closest to ours is by Brandt and Colton [2], who developed a collision avoidance system for quadcopters us- ing a kinesthetic force-feedback device. In this paper vibrotactile signals are NOTICE: This is the author’s version of a work that was accepted for publication in Lecture Notes in Electrical Engineering, vol 432. Springer, Singapore (LNEE, volume 432). Changes resulting from the publishing process, such as peer review, editing, corrections, structural formatting, and other quality control mechanisms may not be reflected in this document. Changes may have been made to this work since it was submitted for publication. A definite version is available under doi: 10.1007/978-981-10-4157-0_66.