Now showing items 1-37 of 37

  • Adaptive Fault Detection and Tolerance for Robots 

    Visinsky, Monica L.; Cavallaro, Joseph R.; Walker, Ian D. (1994-08-01)
    In existing robot fault detection schemes, sensed values of the joint status (position, velocity, etc.) are typically compared against expected or desired values, and if a given threshold is exceeded, a fault is inferred. ...
  • Analysis of Robots for Hazardous Environments 

    Harpel, Barbara McLaughlin; Dugan, Joanne Bechta; Walker, Ian D.; Cavallaro, Joseph R. (1997-01-01)
    Reliability analysis of fault tolerant systems often ignores the small probability that a failure might not be detected or, if detected, may not be properly handled. The probability that the failure is detected and properly ...
  • Dynamic Fault Reconfigurable Intelligent Control Architectures for Robotics 

    Cavallaro, Joseph R.; Walker, Ian D. (1993-04-01)
    In this paper we describe new progress in our development of an Intelligent Control Framework for robots which dynamically reconfigures itself to cope with faults in either sensors or joint hardware. The Framework is ...
  • A Dynamic Fault Tolerance Framework for Remote Robots 

    Visinsky, Monica L.; Cavallaro, Joseph R.; Walker, Ian D. (1995-08-01)
    Fault tolerance is increasingly important for robots, especially those in remote or hazardous environments. Robots need the ability to effectively detect and tolerate internal failures in order to continue performing their ...
  • Dynamic Senor-Based Fault Detection for Robots 

    Visinsky, Monica L.; Cavallaro, Joseph R.; Walker, Ian D. (1993-09-01)
    Fault detection and fault tolerance are increasingly important for robots in space or hazardous environments due to the dangerous and often inaccessible nature of these environs. We have previously developed algorithms to ...
  • Evaluating the reliability of prototype degradable systems 

    Leuschen, Martin L.; Walker, Ian D.; Cavallaro, Joseph R. (2001-04-01)
    The technique introduced in this paper is a new technique for analyzing fault tolerant designs under considerable uncertainty, such as seen in unique or few-of-a-kind devices in poorly known environments or pre-prototype ...
  • Experimental AR Fault Detection Methods for a Hydraulic Robot 

    Leuschen, Martin L.; Walker, Ian D.; Cavallaro, Joseph R.; Gamache, Ronald; Martin, Mike (2000-09-01)
    This paper focuses on practical use and theoretical elaboration of the analytical redundancy technique which is used to efficiently detect faults that have been determined to be mission-hazardous by previous FMECA and fault ...
  • Expert System Framework for Fault Detection and Fault Tolerance in Robotics 

    Visinsky, Monica L.; Cavallaro, Joseph R.; Walker, Ian D. (1994-01-01)
    Fault tolerance is of increasing importance for modern robots. The ability to detect and tolerate failures enables robots to effectively cope with internal failures and continue performing assigned tasks without the need ...
  • Expert System Framework for Fault Detection and Fault Tolerance in Robotics 

    Visinsky, Monica L.; Cavallaro, Joseph R.; Walker, Ian D. (1992-11-01)
    Fault tolerance is of increasing importance for modern autonomous industrial robots. The ability to detect and tolerate failures will enable robots to effectively cope with internal failures and continue performing assigned ...
  • Failure Mode Analysis for a Hazardous Waste Clean-up Manipulator 

    Walker, Ian D.; Cavallaro, Joseph R. (1996-05-01)
    This paper describes the application of Fault Tree Analysis to the design phase of a robot manipulator for hazardous waste retrieval. The robot is to be deployed in single-shell under-ground storage tanks at the US Department ...
  • Failure Mode Analysis of a Proposed Manipulator-based Hazardous Material Retrieval System 

    Cavallaro, Joseph R.; Walker, Ian D. (1997-04-01)
    Failure mode and reliability analysis is particularly important for robot manipulators to be deployed in remote environments, where inspection and repair are diffcult, and reliability is of prime importance. This is ...
  • Fault Detection and Fault Tolerance in Robotics 

    Visinsky, Monica L.; Walker, Ian D.; Cavallaro, Joseph R. (1991-07-01)
    Robots are used in inaccessible or hazardous environments in order to alleviate some of the time, cost and risk involved in preparing men to endure these conditions. In order to perform their expected tasks, the robots ...
  • Fault Residual Generation via Nonlinear Analytical Redundancy 

    Leuschen, Martin L.; Walker, Ian D.; Cavallaro, Joseph R. (2005-05-01)
    Fault detection is critical in many applications, and analytical redundancy (AR) has been the key underlying tool for many approaches to fault detection. However, the conventional AR approach is formally limited to linear ...
  • Fault Tolerant Algorithms and Architectures for Robotics 

    Hamilton, D. L.; Visinsky, Monica L.; Bennett, J. K.; Cavallaro, Joseph R.; Walker, Ian D. (1994-04-01)
    As robot tasks in space, nuclear, and medical environments become more widespread, the issues of reliability and safety for robots are becoming more critical. Attempts to address these issues have resulted in a a recent ...
  • Investigation of Reliability of Hydraulic Robots for Hazardous Environments Using Analytic Redundancy 

    Leuschen, Martin L.; Walker, Ian D.; Cavallaro, Joseph R. (1999-01-01)
    The Rosie mobile worksystem is a robot that is on the cutting edge of hazardous environment robotics. It is a heavy-duty hydraulic robot designed for nuclear reactor decontamination and dismantlement. The robot consists ...
  • Keeping the Analog Genie in the Bottle: A Case for Digital Robots 

    Walker, Ian D.; Cavallaro, Joseph R.; Leuschen, Martin L. (1999-05-01)
    In this paper, we consider the case for adopting a truly 'digital' type of robot, which would evolve between a discrete and finite set of states. We adopt the point of view that the advantages of traditional robotic evolution ...
  • Layered Dynamic Fault Detection and Tolerance for Robots 

    Visinsky, Monica L.; Walker, Ian D.; Cavallaro, Joseph R. (1993-05-01)
    Fault tolerance is increasingly important for space and hazardous environment robotics. Robots need to quickly detect and tolerate internal failures in order to continue performing their tasks without the need for immediate ...
  • Monitoring and Diagnostics for a Hydraulic Robot in Hazardous Environments 

    Leuschen, Martin L.; Cavallaro, Joseph R.; Walker, Ian D. (1999-04-01)
    Hazardous environments are an important application of modern robotic techniques. However, failures can be quite serious in such environments, especially if they trap the robot within or damage containment efforts. Thus ...
  • New Dynamic Model-Based Fault Detection Thresholds for Robot Manipulators 

    Visinsky, Monica L.; Walker, Ian D.; Cavallaro, Joseph R. (1994-05-01)
    Autonomous robotic fault detection is becoming increasingly important as robots are used in more inaccessible and hazardous environments. Detection algorithms, however, are adversely effected by the model simplification, ...
  • New Real-Time Robot Motion Algorithms Using Parallel VLSI Architectures 

    Deo, Arati S.; Cavallaro, Joseph R.; Walker, Ian D. (1991-03-01)
    Real time robot control presents a major numerical challenge. The inverse kinematics problem of determining joint motion for a specified end effector trajectory is formulated as a damped least-squares problem which balances ...
  • Nonlinear Fault Detection for Hydraulic Systems 

    Leuschen, Martin L.; Walker, Ian D.; Cavallaro, Joseph R. (2003-01-01)
    One of the most important areas in the robotics industry is the development of robots capable of working in hazardous environments. As humans cannot safely or cheaply work in these environments, providing a high level ...
  • Nonlinear Fault Detection for Hydraulics: Recent Advances in Fault Diagnosis and Fault Tolerance for Mechatronic Systems 

    Leuschen, Martin L.; Walker, Ian D.; Cavallaro, Joseph R. (2002-10-01)
    One of the most important areas in the robotics industry is the development of robots capable of working in hazardous environments. As humans cannot safely or cheaply work in these environments, providing a high level ...
  • Parallel VLSI Architectures for Real-Time Control of Redundant Robots 

    Walker, Ian D.; Cavallaro, Joseph R. (1991-02-01)
    We present new architectures for the efficient computation of redundant manipulator inverse kinematics. A key component of our architecture is the calculation in VLSI hardware of the Singular Value Decomposition of the ...
  • Parallel VLSI Architectures for Real-Time Kinematics of Redundant Robots 

    Walker, Ian D.; Cavallaro, Joseph R. (1993-05-01)
    We describe new architectures for the efficient computation of redundant manipulator kinematics (direct and inverse). By calculating the core of the problem in hardware, we can make full use of the redundancy by implementing ...
  • Parallel VLSI Architectures for Real-Time Kinematics of Redundant Robots 

    Walker, Ian D.; Cavallaro, Joseph R. (1994-01-01)
    We describe new architectures for the efficient computation of redundant manipulator kinematics (direct and inverse). By calculating the core of the problem in hardware, we can make full use of the redundancy by implementing ...
  • Protective Operating System Shell Environment for Robots 

    Cavallaro, Joseph R.; Walker, Ian D. (1995-10-01)
    This paper describes the synthesis of a protective operating system shell environment for robots. The approach is designed to protect the robot from the effects of errors in the lower level manipulator system and the higher ...
  • Risk and Fault Tolerance Analysis for Robotics and Manufacturing 

    Hamilton, Deirdre L.; Cavallaro, Joseph R.; Walker, Ian D. (1996-05-01)
    This paper describes a novel method for analyzing, within one framework, several important types of risk associated with robotics and manufacturing applications. We will build on the established technique of Fault Tree ...
  • Robot Fault Detection and Fault Tolerance: A Survey 

    Visinsky, Monica L.; Cavallaro, Joseph R.; Walker, Ian D. (1994-01-01)
    Fault tolerance is increasingly important for robots, especially those in remote or hazardous environments. Robots need the ability to effectively detect and tolerate internal failures in order to continue performing their ...
  • Robot Reliability Estimation Using Interval Methods 

    Carreras, Carlos; Walker, Ian D.; Nieto, Octavio; Cavallaro, Joseph R. (1999-02-24)
    Reliability is a critical issue for many robotic applications, where failures can be disastrous. Traditional reliability analysis algorithms depend on the algebraic manipulation of given input data (representing subsystem ...
  • Robot Reliability Through Fuzzy Markov Models 

    Leuschen, Martin L.; Walker, Ian D.; Cavallaro, Joseph R. (1998-01-01)
    In the past few years, new applications of robots have increased the importance of robotic reliability and fault tolerance. Standard approaches of reliability engineering rely on the probability model, which is often ...
  • Robot Reliability Using Fuzzy Fault Trees and Markov Models 

    Leuschen, Martin L.; Walker, Ian D.; Cavallaro, Joseph R. (1996-11-01)
    Robot reliability has become an increasingly important issue in the last few years, in part due to the increased application of robots in hazardous and unstructured environments. However, much of this work leads to complex ...
  • Robotic Fault Detection Using Nonlinear Analytical Redundancy 

    Leuschen, Martin L.; Cavallaro, Joseph R.; Walker, Ian D. (2002-05-01)
    In this paper we discuss the application of our recently developed nonlinear analytical redundancy (NLAR) fault detection technique to a two-degree of freedom robot manipulator. NLAR extends the traditional linear AR ...
  • Robotic Fault Tolerance: Algorithms and Architectures 

    Visinsky, Monica L.; Cavallaro, Joseph R.; Walker, Ian D. (1993-04-01)
    Fault tolerance is an essential factor in ensuring successful autonomous systems, especially for robots working in remote or hazardous environments. To avoid the cost and risk involved in sending humans into these environs ...
  • Safety of Robotic Systems - Guest Editorial 

    Petersen, Kurt E.; Walker, Ian D.; Cavallaro, Joseph R. (1996-09-01)
    We were delighted to be invited by the editors of Reliability Engineering and System Safety to organise a special issue on the Safety of Robotic Systems. Robotic systems have now reached a level of sophistication far ...
  • A Survey of NASA and Military Standards on Fault Tolerance and Reliability Applied to Robotics 

    Cavallaro, Joseph R.; Walker, Ian D. (1994-03-01)
    There is currently increasing interest and activity in the area of reliability and fault tolerance for robotics. This paper discusses the application of Standards in robot reliability, and surveys the literature of relevant ...
  • Testing on the Curve: Nonlinear Analytical Redundancy for Fault Detection 

    Leuschen, Martin L.; Cavallaro, Joseph R.; Walker, Ian D. (2001-03-01)
    One of the most important areas in the robotics industry is the development of robots capable of working in hazardous environments. Providing a high level of functionality in these arenas is important simply because humans ...
  • The Use of Fault Trees for the Design of Robots for Hazardous Environments 

    Walker, Ian D.; Cavallaro, Joseph R. (1996-01-01)
    This paper addresses the application of fault trees to the analysis of robot manipulator reliability and fault tolerance. Although a common and useful tool in other applications, fault trees have only recently been applied ...