Robin R. Murphy

AAAI Conference 2026 Conference Paper

A Benchmark Dataset for Spatially Aligned Road Damage Assessment in Small Uncrewed Aerial Systems Disaster Imagery

• Thomas Manzini
• Priyankari Perali
• Raisa Karnik
• Robin R. Murphy

This paper presents the largest known benchmark dataset for road damage assessment and road alignment, and provides 18 baseline models trained on the CRASAR-U-DRIODs dataset's post-disaster small uncrewed aerial systems (sUAS) imagery from 10 federally declared disasters, addressing three challenges within prior post-disaster road damage assessment datasets. While prior disaster road damage assessment datasets exist, there is no current state of practice, as prior public datasets have either been small-scale or reliant on low-resolution imagery insufficient for detecting phenomena of interest to emergency managers. Further, while machine learning (ML) systems have been developed for this task previously, none are known to have been operationally validated. These limitations are overcome in this work through the labeling of 657.25km of roads according to a 10-class labeling schema, followed by training and deploying ML models during the operational response to Hurricanes Debby and Helene in 2024. Motivated by observed road line misalignment in practice, 9,184 road line adjustments were provided for spatial alignment of a priori road lines, as it was found that when the 18 baseline models are deployed against real-world misaligned road lines, model performance degraded on average by 5.596% Macro IoU. If spatial alignment is not considered, approximately 8% (11km) of adverse conditions on road lines will be labeled incorrectly, with approximately 9% (59km) of road lines misaligned off the actual road. These dynamics are gaps that should be addressed by the ML, CV, and robotics communities to enable more effective and informed decision-making during disasters.

ICRA Conference 2024 Conference Paper

Differentiable Boustrophedon Paths That Enable Optimization Via Gradient Descent

• Thomas Manzini
• Robin R. Murphy

This paper introduces a differentiable representation for the optimization of boustrophedon path plans in convex polygons, explores an additional parameter of these path plans that can be optimized, discusses the properties of this representation that can be leveraged during the optimization process and shows that the previously published attempt at optimization of these path plans was too coarse to be practically useful. Experiments were conducted to show that this differentiable representation can reproduce scores from traditional discrete representations of boustrophedon path plans with high fidelity. Finally, optimization via gradient descent was attempted but found to fail because the search space is far more non-convex than was previously considered in the literature. The wide range of applications for boustrophedon path plans means that this work has the potential to improve path planning efficiency in numerous areas of robotics, including mapping and search tasks using uncrewed aerial systems, environmental sampling tasks using uncrewed marine vehicles, and agricultural tasks using ground vehicles, among numerous others applications.

IROS Conference 2023 Conference Paper

Towards Automated Void Detection for Search and Rescue with 3D Perception

• Ananya Bal
• Ashutosh Gupta 0004
• Pranav Goyal
• David F. Merrick
• Robin R. Murphy
• Howie Choset

In a structural collapse, debris piles up in a chaotic and unstable manner, creating pockets and void spaces that are difficult to see or access. Often, these regions have the highest chances of concealing survivors and identifying such regions can increase the success of a search and rescue (SAR) operation while ensuring the safety of both survivors and rescue teams. In this paper, we present an approach for ex post facto void detection in rubble piles by using registered 3D point clouds reconstructed from aerial images captured at multiple times on the scene. We perform a temporal layering of these point clouds to capture the dynamic surface of the rubble pile from multiple days of the SAR operation and analyze this 3D structure to detect candidate regions corresponding to void spaces. The layering is achieved by a parallel 3D point cloud reconstruction of the scene using the COLMAP Structure from Motion pipeline. The void detection is achieved by applying multiple point filtering criteria in thin segments of the 3D point clouds of the rubble. We test our approach on aerial images collected from the Surfside Structural Collapse at Miami in June 2021. Our method achieves an improvement in registration compared to the use of standard point cloud registration methods on individual 3D reconstructions. Through our method, we see translation errors reduce by 82%. Additionally, our method detects 9 out of 10 void spaces that were observed by experts in the rubble.

IROS Conference 2023 Conference Paper

Wireless Network Demands of Data Products from Small Uncrewed Aerial Systems at Hurricane Ian

• Thomas Manzini
• Robin R. Murphy
• David F. Merrick
• Justin Adams

Data collected at Hurricane Ian (2022) quantifies the demands that small uncrewed aerial systems (UAS), or drones, place on the network communication infrastructure and identifies gaps in the field. Drones have been increasingly used since Hurricane Katrina (2005) for disaster response, however getting the data from the drone to the appropriate decision makers throughout incident command in a timely fashion has been problematic. These delays have persisted even as countries such as the USA have made significant investments in wireless infrastructure, rapidly deployable nodes, and an increase in commercial satellite solutions. Hurricane Ian serves as a case study of the mismatch between communications needs and capabilities. In the first four days of the response, nine drone teams flew 34 missions under the direction of the State of Florida FL-UAS1, generating 636GB of data. The teams had access to six different wireless communications networks but had to resort to physically transferring data to the nearest intact emergency operations center in order to make the data available to the relevant agencies. The analysis of the mismatch contributes a model of the drone data-to-decision workflow in a disaster and quantifies wireless network communication requirements throughout the workflow in five factors. Four of the factors-availability, bandwidth, burstiness, and spatial distribution-were previously identified from analyses of Hurricanes Harvey (2017) and Michael (2018). This work adds upload rate as a fifth attribute. The analysis is expected to improve drone design and edge computing schemes as well as inform wireless communication research and development.

IROS Conference 2018 Conference Paper

Motion Planning for a UAV with a Straight or Kinked Tether

• Xuesu Xiao
• Jan Dufek
• Mohamed Suhail
• Robin R. Murphy

This paper develops and compares two motion planning algorithms for a tethered UAV with and without the possibility of the tether contacting the confined and cluttered environment. Tethered aerial vehicles have been studied due to their advantages such as power duration, stability, and safety. However, the disadvantages brought in by the extra tether have not been well investigated by the robotic locomotion community, especially when the tethered agent is locomoting in a non-free space occupied with obstacles. In this work, we propose two motion planning frameworks that (1) reduce the reachable configuration space by taking into account the tether and (2) deliberately plan (and relax) the contact point(s) of the tether with the environment and enable an equivalent reachable configuration space as the non-tethered counterpart would have. Both methods are tested on a physical robot, Fotokite Pro. With our approaches, tethered aerial vehicles could find their applications in confined and cluttered environments with obstacles as opposed to ideal free space, while still maintaining the advantages from the usage of a tether. The motion planning strategies are particularly suitable for marsupial heterogeneous robotic teams, such as visual servoing/assisting for another mobile, tele-operated primary robot.

IROS Conference 2017 Conference Paper

UAV assisted USV visual navigation for marine mass casualty incident response

• Xuesu Xiao
• Jan Dufek
• Tim Woodbury
• Robin R. Murphy

This research teams an Unmanned Surface Vehicle (USV) with an Unmanned Aerial Vehicle (UAV) to augment and automate marine mass casualty incident search and rescue in emergency response phase. The demand for real-time responsiveness of those missions requires fast and comprehensive situational awareness and precise operations, which are challenging to achieve because of the large area and the flat nature of the water field. The responders, drowning victims, and rescue vehicle are far apart and all located at the sea level. The long distances mean responders cannot clearly discern the rescue vehicle and victims from the surrounding water. Furthermore, being at the same elevation makes depth perception difficult. Rescue vehicle and victims at different distances from the responder will always appear to be close together. This makes it almost impossible for the responders to accurately drive the USV to the victims in time. This paper proposes the use of a UAV to compensate for the lack of elevation of the responders and to automate search and rescue operations. The benefit of this system is two fold: 1) the UAV provides responders with an overhead view of the field, covers larger area than direct visual, and allows more accurate perception of the situation, and 2) it automates the rescue process so that the responders can focus on task-level needs instead of tediously driving the USV to the victims. Thirty autonomous navigation trials in 4 rescue scenarios prove the first known successful implementation of a small UAV visually navigating a USV.

ICRA Conference 2015 Conference Paper

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

• Brittany A. Duncan
• Robin R. Murphy

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.

IROS Conference 2012 Conference Paper

A decade of rescue robots

• Robin R. Murphy

This video offers a retrospective of the 26 disasters where land, marine, or aerial robots have been deployed, starting with the first use of rescue robots at the 2001 World Trade Center Collapse and continuing through the 2011 Tohoku Tsunami/Fukushima nuclear event. While robots have not found a living survivor, possibly because they arrive on average 4. 5 days after the event, the video clips illustrate the contributions of robots to searching for survivors, reconnaissance and mapping, inspection of buildings, and inspection of bridges and shipping channels. The clips also highlight four open research questions: human-robot interaction, mobile manipulation, reliable wireless networks, and obstacle avoidance for UAVs and UMVs. Use of robots is accelerating and their contributions to disaster prevention, preparedness, response, and recovery will grow and lead to new challenges for research.

ICRA Conference 2011 Conference Paper

A multi-disciplinary design process for affective robots: Case study of Survivor Buddy 2. 0

• Robin R. Murphy
• Aaron Rice
• Negar Rashidi
• Zachary Henkel
• Vasant Srinivasan

Designing and constructing affective robots on schedule and within costs is especially challenging because of the qualitative, artistic nature of affective expressions. Detailed affective design principles do not exist, forcing an iterative design process. This paper describes a three step design process created for the Survivor Buddy project that engages artists in the design process and allows animation to guide physical implementation. The process combines creative design of believable agents unconstrained by costs with traditional design decision matrices. The paper provides a case study comparing the resulting design of the Survivor Buddy 2. 0 robot with the original (Survivor Buddy 1. 0). The multi-disciplinary methodology produced a more pleasing and expressive robot that was 50% less expensive, 78% lighter, and up to 700% faster within the same amount of design time. This methodology is expected to contribute to reducing risk in designing cost effective affective robots and robots in general.

IROS Conference 2011 Conference Paper

A rapidly reconfigurable robot for assistance in urban search and rescue

• Alexander Jacob Hunt
• Richard J. Bachmann
• Robin R. Murphy
• Roger D. Quinn

A robot is being developed for urban search and rescue missions. USAR Whegs™ implements several new features into Whegs™ robot design. It is the first quadruped Whegs™ robot of this scale. It uses differential steering and the user can rapidly change its running gear to and from tracks and wheel-legs. This is also the first implementation of carbon fiber wheel-legs on a Whegs™ vehicle. The carbon-fiber reduces the mass moment of inertia eight times compared to previous aluminum designs. The running gear can be changed in 30 seconds and the resulting connections are secure. GeoSystems Zippermast allows a camera to be deployed as high as eight feet above the robot. The robot is 47. 6 cm long, can travel 1. 9 meters per second on its tracks, and can climb 15 cm obstacles using its wheel-legs. A two-speed transmission is being developed to permit it to run more slowly on wheel-legs for better control on irregular terrain.

ICRA Conference 2008 Conference Paper

Preliminary report: Rescue robot at Crandall Canyon, Utah, mine disaster

• Robin R. Murphy
• Jeffery Kravitz
• Ken Peligren
• James Milward
• Jeff Stanway

This video provides a preliminary report of the use of a rescue robot from Aug. 24, to Sept. 2, 2007, at the Crandall Canyon, Utah, mine disaster. The customized Inuktun teleoperated robot was able to traverse over 1, 400 feet through an 8 7/8″ uncased borehole drilled, enter the mine and travel approximately 7 feet. The robot showed that the walls had deteriorated, indicating that a major collapse had occurred. The large debris combined with dense mud created unfavorable navigational conditions for the robot. The robot was lost on the ascent, approximately 52 feet from the surface, due to eroding borehole conditions. The video identifies open research questions.

IROS Conference 2008 Conference Paper

Validating the Search and Rescue Game Environment as a robot simulator by performing a simulated anomaly detection task

• Jeff Craighead
• Rodrigo Gutierrez
• Jennifer L. Burke
• Robin R. Murphy

This paper presents the results from experiments validating the physics and environmental accuracy of a new robot simulation environment, the search and rescue game environment (SARGE), which is the foundation for series of robot-operator training games. An ATRV-Jr. outfitted with a SICK laser, GPS, and compass was used both in the real-world and in a simulated environment modeled after the real-world testing location in a simulated anomaly detection task. The ARTV-Jr. , controlled by the Distributed Field Robotics Architecture, navigated through a series of waypoints in the environment. The simulated ATRV-Jr. matched the actions of the real ATRV-Jr. in both velocity and path similarity within 0. 08 m/s and 0. 7 m respectively.

ICRA Conference 2007 Conference Paper

A Survey of Commercial & Open Source Unmanned Vehicle Simulators

• Jeff Craighead
• Robin R. Murphy
• Jennifer L. Burke
• Brian F. Goldiez

This report presents a survey of computer based simulators for unmanned vehicles. The simulators examined cover a wide spectrum of vehicles including unmanned aerial vehicles, both full scale and micro size; unmanned surface and subsurface vehicles; and unmanned ground vehicles. The majority of simulators use simple numerical simulation and simplistic visualization using custom OpenGL code. An emerging trend is to used modified commercial game engines for physical simulation and visualization. The game engines that are commercially available today are capable of physical simulations providing basic physical properties and interactions between objects. Newer and/or specialized engines such as the flight simulator X-Plane or Ageia PhysX and Havok physics engines, are capable of simulating more complex physical interactions between objects. Researchers in need of a simulator have a choice of using game engines or available open source and commercially available simulators, allowing resources to be focused on research instead of building a new simulator. We conclude that it is no longer necessary to build a new simulator from scratch.

IROS Conference 2007 Conference Paper

Social roles for taskability in robot teams

• Matthew T. Long
• Robin R. Murphy
• James Hicinbothom

This paper demonstrates the use of social roles to enable taskability in multi-robot teams based on a study of roles from the social sciences as well as related work in software agents. It first provides a survey of the current state of role- based robotics. Then, it offers specific examples of how roles can enable behavior with a team of heterogeneous robots using the Distributed Field Robot Architecture to integrate with a cognitive agent. The implementation extends the robot persona, previously utilized for allocating resources within a distributed robot team, and constructs a context adapter to allow each robot to assume a role as directed by the cognitive agent.

IROS Conference 2006 Conference Paper

Cooperative Damage Inspection with Unmanned Surface Vehicle and Micro Unmanned Aerial Vehicle at Hurricane Wilma

• Robin R. Murphy
• Sam Stover
• Kevin S. Pratt
• Chandler Griffin

On Oct 24, 2005, Hurricane Wilma made landfall at Cape Romano, Florida. Two days later, the Center for Robot-Assisted Search and Rescue (CRASAR) deployed an iSENSYS helicopter and an unmanned surface vehicle to survey damage in parts of Marco Island, 11 miles from landfall. Assistance was provided by the National Science Foundation's industry/university cooperative research center on safety security rescue technologies. The AEOS-1 USV was prototype built for environmental science studies. It was modified to carry a Sound Metric Dual frequency IDentification SONar (DIDSON). The DIDSON was able to show the state of underwater structures, schools of small fish swimming, and find the railings from the collapsed section of a pier. This work validates the concept of using USVs and UAVs together for disaster response, suggests missions, and priorities for autonomy. Besides damage inspection, USV-UAV teams can find safe lanes of sea travel and to detect hazardous materials spills. In addition to providing situation awareness, the UAV can serve as a wireless network relay. Inspection of damage to seawalls, docks, and bridges requires vision above the waterline as well as below poses a new type of Simultaneous Localization and Mapping (SLAM).

ICRA Conference 2005 Conference Paper

Application of the Distributed Field Robot Architecture to a Simulated Demining Task

• Matthew T. Long
• Aaron Gage
• Robin R. Murphy
• Kimon P. Valavanis

As mobile robot teams become more complex, it is necessary to develop a control architecture to manage the resources present in the team. The Distributed Field Robot Architecture (DFRA) is a distributed, object-oriented implementation of the SFX hybrid robot architecture that allows for dynamic discovery and acquisition of robot resources and the seamless integration of humans and artificial agents in the robot team. This paper introduces the DFRA and details its application to a high-fidelity demining scenario using a heterogeneous team of ground and aerial robots.

ICRA Conference 2005 Conference Paper

Conflict Metric as a Measure of Sensing Quality

• Jennifer Carlson
• Robin R. Murphy
• Svetlana Chistopher
• Jennifer Casper

This paper shows that the Con metric from Dempster-Shafer theory is a good indicator of sensing quality, where an increase in the conflict metric value correlates with a decrease in map quality (at p ≤ 0. 05). Two sets of experiments were conducted. In one, sonar data were gathered from a Nomad 200 robot operating in typical indoor hallways. Another used sonars on an RWI Urban robot in a confined, irregular tunnel built from eight different construction materials. For each set, an occupancy grid map was built and evaluated through a quantitative comparison with the ground truth. It is expected that the results of this study will generalize not only to other sensors and multi-sensor fusion, but any application where consistency can be assumed. It also contributes a design for an inexpensive reconfigurable confined space testbed.

UAI Conference 2005 Conference Paper

Use of Dempster-Shafer Conflict Metric to Detect Interpretation Inconsistency

• Jennifer Carlson
• Robin R. Murphy

AAAI Conference 2004 Conference Paper

Affective Recruitment of Distributed Heterogeneous Agents

• Aaron Gage
• Robin R. Murphy

Members of multi-robot teams may need to collaborate to accomplish a task due to differences in capabilities. This paper describes an extension of the ALLIANCE architecture that enables agent recruitment within a decentralized UAV-UGV robot team without task preemption but 1) uses a formal model of emotions and 2) handles heterogeneity. Affective computing allows recruitment to be robust under loss of communication between agents and minimizes the number of messages passed. Data from 66 simulations show that the affective strategy succeeds with a random message loss rate up to 25% and requires 19. 1% fewer messages to be sent compared to greedy and random, and that of these, affective scales best with team size. Comparisons of broadcast to unicast messaging are also made in simulation.

IROS Conference 2004 Conference Paper

An investigation of MML methods for fault diagnosis in mobile robots

• Jennifer Carlson
• Robin R. Murphy

The purpose of this study is to evaluate the utility of a diagnosis technique, which uses minimum message length (MML) for autonomous mobile robot fault diagnosis. A simulator was developed for a behavior-based robotic system and results were gathered for over 24, 000 simulations varying the level of test noise and the components with simulated failures. The results showed that the MML diagnosis technique did not perform well as a turn-key solution. In two different data sets, only 0. 59% and 1. 19% of the test cases were correctly diagnosed and none of the cases with multiple failures were identified correctly. This paper presents the approach used to evaluate the new technique, the results, and a discussion of why MML diagnosis may not be appropriate for mobile robotics.

ICRA Conference 2004 Conference Paper

Distributed Error Handling and HRI

• Brian C. Zimmel
• Matthew T. Long
• Jennifer Carlson
• Robin R. Murphy

The implementations of a distributed, autonomous error handler (EH) and a human-robot interface (HRI) are presented. The interface is combined with the EH to allow a human operator to see that a failure has occurred on a robot and whether or not it has been served by the EH. An experiment was run to test how well the EH and the interface work together, as well as the usefulness of the EH. The results were inconclusive, although the EH and interface worked together successfully.

IROS Conference 2004 Conference Paper

Evidence of the need for social intelligence in rescue robots

• Thomas David Fincannon
• Laura E. Barnes
• Robin R. Murphy
• Dawn L. Riddle

This study investigates data collected from operating an Inuktun robot in an urban search and rescue (USAR) confined space training exercise task at Virginia Beach Training Center. Data was collected from coding approximately one hour of video. The video had no sound so all analysis is based on the video feed. Indicators of communication, gestures, physical interactions with the robot, and robot movements were analyzed. The findings indicate that the robot emerges as a virtual presence for the support of the team outside of the confined space. The team members spontaneously responded socially to the robot despite the robot not being engineered to have a social intelligence. This confirms numerous studies in the cognitive science, psychology, and affective computing literature that robots need a social interface regards of domain.

ICRA Conference 2004 Conference Paper

Follow-up Analysis of Mobile Robot Failures

• Jennifer Carlson
• Robin R. Murphy
• Andrew L. Nelson

Mobile robot reliability must be guaranteed before they can be employed in hazardous domains like mine clearing or nuclear waste handling, but recent studies of robots used in urban search and rescue and military scenarios have shown a mean time between failures (MTBF) in the field of 6 to 20 hours. This paper extends previous work characterizing robot failures by including recent data and organizing failures according to a novel taxonomy, which includes human failures. Failure type and frequency data were collected from 15 robots representing three manufacturers and seven models over a period of three years, in a variety of environments. Standard manufacturing measures for product reliability were used. The results show that overall MTBF and availability have improved since the previous analysis but are still low. The MTBF across all robot types was 24 hours and availability was 54%. The control system was the most common source of failures (32%), followed by the mechanical platform. Statistical analysis shows that the time between failures, time to repair, and downtime vary widely. For this reason the means reported here are not reliable predictors for future failures, but still provide information on the overall frequency and consequences of mobile robot failures.

IROS Conference 2004 Conference Paper

Incorporation of MATLAB into a distributed behavioral robotics architecture

• Andrew L. Nelson
• Lefteris Doitsidis
• Matthew T. Long
• Kimon P. Valavanis
• Robin R. Murphy

This paper presents a method that integrates MATLAB into a distributed behavioral robotics architecture. The architecture is written in Java and uses the Jini platform for distributed object registration, lookup and remote method invocation. The method described here can be used to integrate MATLAB into any Java-based behavioral architecture. The form of the integration allows a running MATLAB workspace to be accessed as a distributed object within the larger Java/Jini-based architecture. This is beneficial because MATLAB scripts and functions may be called in interpreted form and can make full use of MATLAB tool boxes and have access to the MATLAB workspace environment. This is not possible when MATLAB scripts are compiled into stand-alone C++, Java or p-code. The use of the architecture is demonstrated on an iRobot ATRV-JR robot and remote computer workstation. Experiments have been conducted to quantify GPS and odometry errors in outdoor environments using automated methods supported by the distributed architecture.

IROS Conference 2003 Conference Paper

Distributed multi-agent diagnosis and recovery from sensor failures

• Matthew T. Long
• Robin R. Murphy
• Lynne E. Parker

This paper presents work extending previous research in sensor fault tolerance, classification, and recovery from a single robot to a heterogeneous team of distributed robots. This approach allows teams of robots to share knowledge about the working environment, sensor and task state, to diagnose failures and also communicate to redistribute tasks in the event that a robot becomes inoperable. Our work presents several novel extensions to prior art: distributed fault handling and task management in a dynamic, distributed Java framework. This research was implemented and demonstrated on robots in a lab environment performing a simplified search operation.

ICRA Conference 2003 Conference Paper

Reliability Analysis of Mobile Robots

• Jennifer Carlson
• Robin R. Murphy

Failure data on mobile robots is critical for three reasons: to support the theory of autonomous fault detection, identification, and recovery necessary for success in new domains; provide design and manufacturing feedback to the robotics community; and permit project managers to accurately create development schedules. The failures considered in this paper occurred over a period of 2 years, in a variety of environments. Failure type and frequency data were collected from thirteen robots representing three manufacturers and seven models. The data was analyzed using standard manufacturing measures for the reliability of a product. The mean time between failures represents the average time to the next failure. Availability was used to gauge the impact of a failure on a project. The results show that the reliability for mobile robots is low, with an average MTBF of 8 hours and availability of less than 50%. The platform itself was the source of most failures (42%) for field robots, while the control system was responsible for 29% of the failures.

ICRA Conference 2002 Conference Paper

Workflow Study on Human-Robot Interaction in USAR

• Jennifer Casper
• Robin R. Murphy

This paper presents findings from field trials observing human-robot interaction between certified rescue workers and two types of tactical mobile robots at a rescue training site. Data was collected on how members of a fire rescue department directed the use of two types of robots for four tasks (climbing stairs to investigate condition of upper floors, searching dark, cluttered environments with two different sensor suites, and exploring vertical voids). The prototypical workflow, the type and frequency of errors during each task, how the robot workflow compared with existing urban search and rescue (USAR) practices, and any additional information that came out during debriefing is reported for each task. Two major workflow patterns that could be partially or fully automated were identified: stairwell search and topological search. In addition, collaborative teleoperation appeared to be an important multi-robot strategy. Rescue workers rated the robots' performance superior to existing methods for searching and for exploring vertical voids, but not for stairwells.

IROS Conference 2000 Conference Paper

Biomimetic search for urban search and rescue

• Robin R. Murphy

A key objective for a mobile robot in urban search and rescue (USAR) is to efficiently fined survivors, get near enough to communicate and/or drop off communications and biomedical monitoring gear. This paper discusses a biomimetic search strategy extracted from ethological studies of how insects and animals forage for food, and cognitive studies of how children search for objects. This leads to a biomimetic search organization where a robot partitions the search space based on the semantic understanding of the expected distribution of survivors, then systematically searches each of the volumes in ranked order. While in transit between volumes, the robot conducts a passive opportunistic search. The paper also describes how this search strategy is being implemented and evaluated on a mobile robot for two upcoming USAR competitions.

IROS Conference 2000 Conference Paper

Sensor allocation for behavioral sensor fusion using min-conflict with happiness

• Aaron Gage
• Robin R. Murphy

For mobile robots employing reactive behaviors, allocation of physical sensors to satisfy sensing needs should be dynamic and fast. It is becoming increasingly apparent that this allocation should also support behavioral sensor fusion, as indicated by experimental data, in order to maximize the use of available sensing hardware and to increase the quality of sensing. These issues are addressed in the context of the min-conflict with happiness algorithm for dynamic sensor allocation, whose execution rates on two real robots ranged from 11 to 17 milliseconds. Experimental results are shown which illustrate the improvements (27. 5%-75% of observations) achieved using sensor fusion. The paper also contributes a quantitative representation of sensing quality using t-norms, allowing fused sensors to be compared with single sensors for a behavior.

IROS Conference 1999 Conference Paper

Allocating sensor resources to multiple behaviors

• Aaron Gage
• Robin R. Murphy

This paper presents an algorithm for allocating sensing resources for an autonomous mobile robot with logically redundant sensing capabilities. The algorithm creates a partial plan based on the set of requests by behaviors. If two or more behaviors place conflicting requests, a variant of the MIN-CONFLICT algorithm is used to find a replacement logical sensor. Unlike traditional MIN-CONFLICT, our variant maximizes each behavior's preference for a particular sensor ("happiness"). Simulations compared MIN-CONFLICT with Happiness to other methods (random and greedy assignment) for 10 sequences of 20 random requests for 8 sensors from up to 11 concurrent behaviors. Results showed that it is able to generate more schedules (on the order of 71% to 155% more) and that a further variant could maximize happiness better (7% to 30%).

AAAI Conference 1997 Conference Paper

Intelligent Sensor Fusion for the 1997 AAAI Mobile Robot Competition

• Robin R. Murphy

IJCAI Conference 1997 Conference Paper

Reactive Combination of Belief Over Time Using Direct Perception

• Robin R. Murphy
• Dale K. Hawkins
• Marcel J. Schoppers

One issue for autonomous mobile robots operating in unknown, or partially known, domains is how to handle uncertainty in their sensor observations over time. Methods such as probablistic belief networks and survivor functions are generally unsatisfactory because they require explicit models of the robot's interactions with its environment, including possible contravening events. This information is difficult to obtain, and is philosophically incompatible with reactive behaviors. This paper presents an approach which eliminates the need for explicit models and reasoning; instead, it relies solely on directly perceivable attributes of the robot, object, and environment. The attributes qualitatively rate whether the robot's current observations are from an inherently more informed state than previous readings (e. g. , from a better viewpoint). Observations from more informed states have different rates for the accrual and attrition of belief than those taken from less informed states. This paper describes the implementation, focusing on how the information state is computed using fuzzy logic, and how the state dynamically adapts a variation of Dempster's rule to generate the total belief. Data from a mobile robot tracking an unknown object demonstrates that the reactive computation of belief over time performs well for six canonical accrual and attrition cases.

ICRA Conference 1997 Conference Paper

When to explicitly replan paths for mobile robots

• Robin R. Murphy
• Alisa Marzilli
• Ken Hughes

This paper investigates a range of strategies for determining when to explicitly replan paths. An computationally inexpensive event-driven method is presented which allows the robot to execute an a priori path reactively until a significant deviation in the path occurs, at which point the robot explicitly replans. The event-driven strategy is compared to replanning after every move, and replanning after every n moves on a mobile robot for a wide variety of influences, including different unmodeled obstacle configurations and densities, and quality of the a priori map. The paper concludes that, in general, planning as frequently as resources permits results in smoother actual paths and faster completions. However, if the updated map is inaccurate, the event-driven method is superior.

ICRA Conference 1996 Conference Paper

An explicit path planner to facilitate reactive control and terrain preferences

• Robin R. Murphy
• Ken Hughes
• Eva Noll

This paper presents a new approach to reactive control utilizing the output of an explicit path planner which considers terrain preferences. To demonstrate the concept, a wavefront propagation, type of planner algorithm, Trulla, is integrated into a reactive framework and used as part of the overall architecture. Terrain preferences are represented as weights or costs which are considered in generating a near optimal path. The algorithm is demonstrated on the CSM Denning-Branch MRV4 mobile robot for three scenarios: navigation out of a box canyon, planning with terrain preferences, and opportunistic path improvement.

IROS Conference 1996 Conference Paper

Behavioral speed control based on tactical information

• Robin R. Murphy
• Dale K. Hawkins

This paper presents a novel organization of reactive behaviors which avoids the problems generally associated with arbitration or combination of behaviors. The organization uses tactical behaviors to attempt to safely satisfy the intent of strategic behaviors given the immediate situation (e. g. , state of the environment, status of the robot, certainty, etc.) A tactical speed control behavior using fuzzy logic is described in detail. Experiments with a nonholonomic mobile robot navigating a 150 ft course show that a tactical speed control behavior improves navigational performance without requiring either knowledge about the strategic behavior (follow-line) or the complexity of the course. The speed control behavior has also been used in conjunction with shared control and has been transferred to a holonomic robot, demonstrating how the behavioral organization enhances software modularity and portability.

AAAI Conference 1996 Conference Paper

Classifying and Recovering from Sensing Failures in Autonomous Mobile Robots

• Robin R. Murphy

This paper presents a characterization of sensing failures in autonomous mobile robots, a methodology for classification and recovery, and a demonstration of this approach on a mobile robot performing landmark navigation. A sensing failure is any event leading to defective perception, including sensor malfunctions, software errors, environmental changes, and errant expectations. The approach demonstrated in this paper exploits the ability of the robot to interact with its environment to acquire additional information for classification (i. e. , active perception). A Generate and Test strategy is used to generate hypotheses to explain the symptom resulting from the sensing failure. The recovery scheme replaces the affected sensing processes with an alternative logical sensor. The approach is implemented as the Sensor Fusion Effects Exception Handling (SFX-EH) architecture. The advantages of SFX-EN are that it requires only a partial causal model of sensing failure, the control scheme strives for a fast response, tests are constructed so as to prevent confounding from collaborating sensors which have also failed, and the logical sensor organization allows SFX-EH to be interfaced with the behavioral level of existing robot architectures.

AAAI Conference 1996 Conference Paper

Clementine: Colorado School of Mines

• Robin R. Murphy

The Colorado School of Mines (CSM) is fielding a team comprised of undergraduates in Computer Science or Engineering who are enrolled in the Robotics and AI Minor. The intent is to provide a forum for the students to a) transfer what they have learned in the classroom to a more realistic setting, b) meet with top researchers in the field, c) have an undergraduate research experience, and d) have fun. The students work with the team advisor and graduate students at CSM to integrate and modify code developed for NSF, ARPA, and NASA funded research projects. This will be the fourth year CSM has participated in the competition. The team’s platform is Oementine, a Denning-Branch MRV-4 research robot. She has a ring of 24 ultrasonics, a laser navigation system, and supports two cameras. All processing is done onboard by a 75MHz Pentium processor. A SoundBlaster board and speakers provides feedback on the robot’s activities. Clementine is used for research in indoor task domains such as the surveillance and maintenance of stockpiles of hazardous materials, site assessment of dangerous environments such as a burning building or a collapsed mine, or security. A custom robot, C2, is used for outdoor environments.

IROS Conference 1996 Conference Paper

Incorporating terrain uncertainties in autonomous vehicle path planning

• Kevin K. Gifford
• Robin R. Murphy

While inherent uncertainty in obstacle location for autonomous vehicle path planning has been investigated previously, terrain map uncertainty has largely been ignored. The terrain map is constructed via a priori data that in general, is incorrectly utilized as "perfect information". In this paper a probabilistic approach using empirical loss functions is developed to incorporate terrain map uncertainties into the path planning process. A new graph search method is introduced that allows the inclusion of negative weight edges on a optimally planned path. Representative results from forty simulations are presented which indicate that the incorporation of terrain map uncertainty can affect the planned paths that are generated for an autonomous robotic vehicle.

IROS Conference 1996 Conference Paper

Use of scripts for coordinating perception and action

• Robin R. Murphy

This paper proposes scripts as a framework for coordinating and controlling a collection of behaviors needed to perform a highly stereotyped task. Scripts facilitate planning by explicitly representing the types of situations the behaviors are suited for, and the default schedule or plan of activities. They support building abstract behaviors from libraries of primitive independent behaviors by providing the meta-knowledge needed to smooth over minor incompatibilities. Scripts enable robust execution, allowing subscripts to be attached for reacting to anomalous conditions. The utility of scripts is demonstrated via a case study of topological navigation. In this case study, scripts provided the foundation for the abstract navigation behaviors used by a mobile robot to travel through indoor office spaces.

IROS Conference 1992 Conference Paper

Sfx: An Architecture For Action-oriented Sensor Fusion

• Robin R. Murphy
• Ronald C. Arkin

IROS Conference 1989 Conference Paper

Mobile Robot Docking Operations in a Manufacturing Environment: Progress in Visual Perceptual Strategies

• Ronald C. Arkin
• Robin R. Murphy
• Mark Pearson
• David Vaughn