Brittany A. Duncan

Comfortable approach distance with small Unmanned Aerial Vehicles

This paper presents the first known human-subject study of comfortable approach distance and height for human interaction with a small unmanned aerial vehicle (sUAV), finding no conclusive difference in comfort with a sUAV approaching a human at above head height or below head height. Understanding the amount, if any, of discomfort introduced by a sUAV flying in close proximity to a human is critical for law enforcement, crowd control, entertainment, or flying personal assistants. Previous work has focused on how humans interact with each other or with unmanned ground vehicles, and the experimental methods typically rely on the human participant to consciously express distress. The approach taken was to duplicate the experimental set up in human proxemics studies, while adding psychophysiological sensing, under the hypothesis that human-robot interaction will mirror human-human interaction. The 16 participant, within-subjects experiment did not confirm this hypothesis. Instead a sUAV above height of a “tall” person in human experiments (2.13 m) did not produce statistically different heart rate variability nor cause the participant to stop the robot further away than for a sUAV at a “short” height (1.52 m). The lack of effect may be due to two possible confounds: i) duplicating prior human proxemics experiments did not capture how a sUAV would likely move or interact and ii) telling the participants that the robot could not hurt them. Despite possible confounding, the results raise the question of whether human-human psychological and physical distancing behavior transfers to human-aerial robot interactions.

Autonomous Capabilities for Small Unmanned Aerial Systems Conducting Radiological Response: Findings from a High-fidelity Discovery Experiment

This article presents a preliminary work domain theory and identifies autonomous vehicle, navigational, and mission capabilities and challenges for small unmanned aerial systems SUASs responding to a radiological disaster. Radiological events are representative of applications that involve flying at low altitudes and close proximities to structures. To more formally understand the guidance and control demands, the environment in which the SUAS has to function, and the expected missions, tasks, and strategies to respond to an incident, a discovery experiment was performed in 2013. The experiment placed a radiological source emitting at 10 times background radiation in the simulated collapse of a multistory hospital. Two SUASs, an AirRobot 100B and a Leptron Avenger, were inserted with subject matter experts into the response, providing high operational fidelity. The SUASs were expected by the responders to fly at altitudes between 0.3 and 30 m, and hover at 1.5i¾?m from urban structures. The proximity to a building introduced a decrease in GPS satellite coverage, challenging existing vehicle autonomy. Five new navigational capabilities were identified: scan, obstacle avoidance, contour following, environment-aware return to home, and return to highest reading. Furthermore, the data-to-decision process could be improved with autonomous data digestion and visualization capabilities. This article is expected to contribute to a better understanding of autonomy in a SUAS, serve as a requirement document for advanced autonomy, and illustrate how discovery experimentation serves as a design tool for autonomous vehicles.

Lek behavior as a model for multi-robot systems

Lek behavior is a biological mechanism used by male birds to attract mates by forming a group. This project explores the use of a biological behavior found in many species of birds to form leks to guide the creation of groups of robots. The lek behavior provides a sound basis for multi-robot formation because it demonstrates a group of individual entities forming up around a scarce resource. This behavior can be useful to robots in many situations, with an example scenario the case in which robots were dropped via parachute into an area and then needed to form meaningful task-oriented groups.

A preliminary model for comfortable approach distance based on environmental conditions and personal factors

This paper presents a model of “comfortable distance” that captures the factors and conditions known to affect personal space in human-human and human-robot interactions, as well as any identified relationships between them. In the first known human-robot interaction (HRI) survey on approach distance, 19 papers were reviewed and the “comfortable distance” model was synthesized with three distinct types of inputs: environmental conditions, personal factors, and agent factors. Five environmental conditions (lighting, ceiling height, indoor/outdoor, room size, and barrier height) and seven personal factors (gender, age, mood, personality, pet ownership, robot experience, and sitting/standing) structure the model, with four agent factors (angle of approach, height of agent, speed of approach, and gaze) used as tuning parameters to produce behaviors with appropriate distances. Currently, HRI researchers generally focus on one factor at a time (e.g., approach angle or approach speed), without considering the previous work in adjacent fields, such as psychology and other social sciences. This has resulted in environmental factors being ignored by the HRI community. The “comfortable distance” model is a new tool for HRI researchers and is expandable so that it can incorporate new factors as they are identified. This survey will inform researchers about factors which had been previously overlooked in the field of HRI and will allow future researchers to consider the impact of identified variables to create more complete experiments.

Exploratory results for a mission specialist interface in micro unmanned aerial systems

This paper presents a human-robot interaction (HRI) exploratory study of a dedicated Mission Specialist interface for micro unmanned aerial systems (UAS). Current HRI findings from the micro UAS literature suggest that a Mission Specialist role requires a small, mobile, and visual interface that is dedicated and software-based. A literature survey of humanrobot team modeling, human-machine interaction technologies, and interaction principles applicable to micro UAS, resulted in an identified HRI investigation framework, five synthesized design guidelines, and a system architecture for a dedicated Mission Specialist interface. The interface was implemented and evaluated through an exploratory field study involving 16 specialized emergency responders. Observations from the study suggested that with refinements, a dedicated Mission Specialist interface could be a useful tool for future HRI studies to explore role performance in micro UAS.

Sky writer: sketch-based collaboration for UAV pilots and mission specialists

Sky Writer is a collaborative communication medium that augments the traditional display of a UAV pilot and allows other stakeholders to communicate their needs and intentions to the pilot. UAV pilots engaging in time-critical missions, such as urban disaster responses, often must allocate most of their cognitive capacity towards flight tasks, making communication and collaboration with other stakeholders difficult or dangerous. Sky Writer addresses the needs of stakeholders while requiring minimal cognitive effort from the UAV pilot. The application presents stakeholders with an interface that provides contextual flight information and a live video stream of the flight. Stakeholders are able to sketch directly on the video stream or use a spotlight indicator that is mirrored across all displays in the system, including the pilots display. The application can be used in any modern web browser and works with traditional and touch devices. Concept experimentation performed at Disaster City with two pilots indicated that the spotlight feature was particularly useful while the UAV was in motion, and the sketching features were most useful while the UAV was stationary. The system will be tested with professional responders soon to determine its efficacy in a simulated response, and to inform the ongoing design process.

Effects of Speed, Cyclicity, and Dimensionality on Distancing, Time, and Preference in Human-Aerial Vehicle Interactions

This article will present a simulation-based approach to testing multiple variables in the behavior of a small Unmanned Aerial Vehicle (sUAV), inspired by insect and animal motions, to understand how these variables impact time of interaction, preference for interaction, and distancing in Human-Robot Interaction (HRI). Previous work has focused on communicating directionality of flight, intentionality of the robot, and perception of motion in sUAVs, while interactions involving direct distancing from these vehicles have been limited to a single study (likely due to safety concerns). This study takes place in a Cave Automatic Virtual Environment (CAVE) to maintain a sense of scale and immersion with the users, while also allowing for safe interaction. Additionally, the two-alternative forced-choice method is employed as a unique methodology to the study of collocated HRI in order to both study the impact of these variables on preference and allow participants to choose whether or not to interact with a specific robot. This article will be of interest to end-users of sUAV technologies to encourage appropriate distancing based on their application, practitioners in HRI to understand the use of this new methodology, and human-aerial vehicle researchers to understand the perception of these vehicles by 64 naive users. Results suggest that low speed (by 0.27m, p < 0.02) and high cyclicity (by 0.28m, p < 0.01) expressions can be used to increase distancing; that low speed (by 4.4s, p < 0.01) and three-dimensional (by 2.6s, p < 0.01) expressions can be used to decrease time of interaction; and low speed (by 10.4%, p < 0.01) expressions are less preferred for passability in human-aerial vehicle interactions.

Comparison of flight paths from fixed-wing and rotorcraft small unmanned aerial systems at SR530 mudslide Washington state

This work provides a case study of both fixed-wing and rotorcraft small unmanned aerial systems (SUAS) used in a deployment at the SR530 mudslides in Washington state and compares the types of flight paths used by each vehicle type. Previously aerial imagery from SUAS have produced 2D and 3D reconstructions of simple terrain, but have not been used in complex terrain which encompasses both flat areas and drastic changes in the height of ground level, such as a mudslide. In this deployment, both types of SUAS platforms were used to collect imagery over terrain varied nearly 200m in elevation but different paths were used due to the complexity of the terrain, safety, privacy, and platform-specific limitations. The deployment found that paths with fixed-wing platforms can be thought of as stacked horizontal planes while rotorcraft can cover complex terrain with a set of vertical planes. The different paths contribute to autonomous path planning, particularly to accommodate vertical planes, and to general understanding of how different SUAS can be applied to challenging terrains. Future work in path planning should incorporate Geographic Information Systems (GIS) information to facilitate flight paths in vertical planes and to maintain altitude restrictions relative to radically changing elevations of a landscape.

AR browser for points of interest in disaster response in UAV imagery

This work in progress describes AerialAR, a global positioning system (GPS) augmented reality (AR) application for mobile devices that automatically labels points of interest (POI) in unmanned aerial vehicle (UAV) imagery. This has important implications for assisting emergency responders. Existing AR applications for UAVs provide the pilot with navigational situational awareness such as terrain features; AerialAR locates and labels mission-relevant points such as schools that may need to be evacuated or hospitals to transport victims to. Locating POI in UAV imagery poses more challenges than those addressed by typical AR browsers on smartphones. The UAV operates at different altitudes as opposed to handheld devices and the UAV camera can tilt over a wide range of angles rather than simply facing forward. AerialAR overcomes these issues by developing a set of equations that translate UAV telemetry and field of view (fov) into a projection onto a Google Map. The map can then be queried for categories of POI. The current version calculates the POI distance and angles with an average error of 0.04% as compared to the Haversine and Rhumb line equations for the distance between the UAV location projected on the ground and the POI on the Google Map. Future work will complete AerialAR by processing UAV video in real-time on mobile devices.

Field study identifying barriers and delays in data-to-decision with small unmanned aerial systems

This paper reports on lessons learned in rapidly getting data from a small tactical unmanned aerial system (sUAS) to an incident commander during a 2012 high fidelity hazardous materials exercise. In order to capture the Public Safety data-to-decision path, observational data was collected on three flights of an AirRobot 100B sUAS, used extensively by the US Army, with HazMat specialists as part of a chemical train derailment exercise at the 2012 Summer Institute at Disaster City®. The Summer Institute found that (i) the data path requires an average of 4 steps to go from the field to the incident commander, (ii) there is no standard data format which reduces the value of the data nor agreed upon paths for submission which leads to “broken” paths, (iii) redundant data-to-decision paths are essential in order to ensure information flow, and (iv) the average time from when the data was seen by the sUAS to its arrival at incident command was 27.8 minutes. The observations also led to three recommendations for companies producing devices: (i) sUAS should have a reliable capability to record to USB flash drive; (ii) all video and photographic imagery should have the relevant GPS and heading information embedded in the data; and (iii) systems should have the ability to provide cellular and wireless transmission capabilities (including web browsers and email) as responders may not have access to public phone Wi-Fi and internal Ethernet networks. The analysis also suggests that current measures of quality of service (QoS) focus only on device-to-device transfer rates, not the when the decision maker sees the data and if it is in a form to act upon.