Elena R. Messina

Test arenas and performance metrics for urban search and rescue robots

In this paper, we discuss the development and proliferation of robot test arenas that provide tangible, realistic, and challenging environments for mobile robot researchers interested in urban search and rescue applications and other unstructured environments. These arenas allow direct comparison of robotic approaches, objective performance evaluation, and can ultimately provide a proving ground for field-able robotic systems such as those used at the World Trade Center collapse. International robot competitions using these arenas require robots to negotiate complex and collapsed structures, find simulated victims, and generate human readable maps of the environment. A performance metric is presented which quantifies several pertinent robot capabilities and produces an overall score used to evaluate and compare robotic implementations. Future directions for the arenas and the competitions are also discussed.

A robot ontology for urban search and rescue

The goal of this Robot Ontology effort is to develop and begin to populate a neutral knowledge representation (the data structures) capturing relevant information about robots and their capabilities to assist in the development, testing, and certification of effective technologies for sensing, mobility, navigation, planning, integration and operator interaction within search and rescue robot systems. This knowledge representation must be flexible enough to adapt as the robot requirements evolve. As such, we have chosen to use an ontological approach to representing these requirements. This paper describes the Robot Ontology, how it fits in to the overall Urban Search and Rescue effort, how we will be proceeding in the future.

Autonomy Levels for Unmanned Systems (ALFUS) Framework: An Update

The initial construct of the framework for the Autonomy Levels of Unmanned Systems (ALFUS) was presented in the 2004 SPIE Defense and Security Symposium. This paper describes the continuing development effort and further accomplishments made by the Ad Hoc working group. We focus on two elements of the ALFUS product set, namely, the detailed model that is being implemented as a spreadsheet-based tool and the summary model. We also discuss identified challenges.

Design and validation of a Whegs robot in USARSim

Simulation of robots and other vehicles in a virtual domain has multiple benefits. End users can employ the simulation as a training tool to increase their familiarity and skill with the vehicle without risking damage to the robot, potential bystanders, or the surrounding environment. Simulation allows researchers and developers to benchmark the robots performance in a range of scenarios without needing to physically have the robot and or necessary environment(s) present. Beyond benchmarking current designs, researchers and developers can use the information gathered in the simulation to guide and generate new design concepts. USARSim (Urban Search and Rescue Simulation) is a high fidelity simulation tool that is being used to accomplish these goals within the realm of search and rescue. One particular family of robots that can benefit from simulation in the USARSim environment is the Whegs#8482; series of robots developed in the Biologically Inspired Robotics Laboratory at Case Western Reserve University. Whegs robots are highly mobile ground vehicles that use abstracted biological principles to achieve a robust level of terrestrial locomotion. This paper describes a Whegs robot model that was designed and added to USARSims current array of robots. The model was configured to exhibit the same kind of behavioral characteristics found in the real Whegs vehicles. Once these traits were implemented, a preliminary validation study was performed to ensure that the robot interacted with its environment in the same way that the real-life robot would.

A feature-based inspection and machining system

Abstract This paper 1 describes an architecture for a system for machining and inspecting mechanical piece parts and an implementation of it called the Feature-Based Inspection and Control System (FBICS). In FBICS, the controller of a machining center or coordinate measuring machine uses a standard feature-based description of the shape of the object to be made as a principal input for machining and/or inspection. FBICS is a hierarchical control system and performs automated hierarchical process planning. FBICS serves: (1) to demonstrate feature-based inspection and control in an open-architecture control system; (2) as a testbed for solving problems in feature-based manufacturing; and (3) to test the usability of STEP methods and models.

Performance evaluation of autonomous mobile robots

The National Institute of Standards and Technology (NIST) has initiated a program to develop quantitative metrics for machine intelligence. One of the possible approaches to evaluating machine intelligence is task‐based performance testing, like a mouse in a maze. A series of application‐specific testbeds is envisioned. NIST has created a set of reference test arenas for evaluating the performance of autonomous mobile robots performing urban search and rescue tasks. Robots must explore the maze‐like test course, map the environment, find the simulated victims, and then report back their findings. In this paper, we describe our approach toward developing performance metrics for autonomous mobile robots through standardized testing within representative environments and objective performance evaluations. Our intent is to help accelerate the robotic research communities’ advancement of mobile robot capabilities, thereby improving the effectiveness of robots performing within industrial settings, hazardous en...

Design and workspace analysis of a 6-6 cable-suspended parallel robot

In this paper, we study the design and workspace of a 6-6 cable-suspended parallel robot. The workspace volume is characterized as the set of points where the centroid of the MP (MP) can reach with tensions in all suspension cables at a constant orientation. This paper attempts to tackle some aspects of optimal design of a 6DOF cable robot by addressing the variations of the workspace volume and the accuracy of the robot using different geometric configurations, different sizes and orientations of the MP. The global condition index is used as a performance index of a robot with respect to the force and velocity transmission over the whole workspace. The results are used for design analysis of the cable-robot for a specific motion of the MP.

Iterative registration of 3D LADAR data for autonomous navigation

This paper describes an iterative algorithm for registration of 3D LADAR data. The proposed approach is iconic in nature with suitable modifications to deal with false/spurious matches, occlusions and outliers. Experimental results using data obtained from field trials on an experimental unmanned vehicle (XUV) are presented to demonstrate the efficacy of the approach. The paper also details ongoing research efforts to determine the feasibility of employing the algorithm for real-time autonomous navigation.

How task analysis can be used to derive and organize the knowledge for the control of autonomous vehicles

Abstract The real-time control system (RCS) methodology has evolved over a number of years as a technique to capture task knowledge and organize it in a framework conducive to implementation in computer control systems. The fundamental premise of this methodology is that the present state of the task activities sets the context that identifies the requirements for all the support processing. In particular, the task context at any time determines what is to be sensed in the world, what world model states are to be evaluated, which situations are to be analyzed, what plans should be invoked, and which behavior generation knowledge is to be accessed. This results in a methodology that concentrates first and foremost on the task definition. It starts with the definition of the task knowledge in the form of a decision tree that clearly represents the branching of tasks into layers of simpler and simpler subtask sequences. This task decomposition framework is then used to guide the search for and to emplace all of the additional knowledge. This paper explores this process in some detail, showing how this knowledge is represented in a task context-sensitive relationship that supports the very complex real-time processing the computer control systems will have to do.

The challenge of intelligent systems

Analyzes the meaning of intelligence within the domain of intelligent control. Because of historical reasons, there are varying and diverse definitions of what constitutes an intelligent control system. Due to the multidisciplinary nature of intelligent control, there are no good formal measures for what is an intelligent controller or for its performance. We argue that there are characteristics which can be used to categorize a controller as being intelligent. Furthermore, the measure of how intelligent a system is should take into account a holistic view of the systems operations and design requirements. Beginning with the definition of intelligence characteristics and performance measures, we can move towards a science of intelligent systems for control.