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Robotics and Automation, IEEE Transactions on

Issue 3 • Date June 1999

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  • Foreword special section on virtual reality in robotics and automation

    Publication Year: 1999 , Page(s): 397 - 399
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    Freely Available from IEEE
  • Stable haptic interaction with virtual environments

    Publication Year: 1999 , Page(s): 465 - 474
    Cited by:  Papers (186)  |  Patents (2)
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    This paper addresses fundamental stability and performance issues associated with haptic interaction. It generalizes and extends the concept of a virtual coupling network, an artificial link between the haptic display and a virtual world, to include both the impedance and admittance models of haptic interaction. A benchmark example exposes an important duality between these two cases. Linear circuit theory is used to develop necessary and sufficient conditions for the stability of a haptic simulation, assuming the human operator and virtual environment are passive. These equations lead to an explicit design procedure for virtual coupling networks which give maximum performance while guaranteeing stability. By decoupling the haptic display control problem from the design of virtual environments, the use of a virtual coupling network frees the developer of haptic-enabled virtual reality models from issues of mechanical stability View full abstract»

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  • Conformational switching in self-assembling mechanical systems

    Publication Year: 1999 , Page(s): 510 - 520
    Cited by:  Papers (7)  |  Patents (2)
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    A study of 1D self-assembly of a type of mechanical conformational switches, minus devices is presented where assembly occurs via the sequential mating of a random pair of parts selected from a part bin, referred to as sequential random bin-picking. The minus devices facilitate the robust yield of a desired assembly against the variation in the initial fraction of the part types, by specifying a fixed assembly sequence during the self-assembling process. It is also found that while the minus devices can “encode” some assembly sequences, encoding other assembly sequences requires the use of another type of conformational switches, plus devices. It is proved that the local rules corresponding to the minus and plus devices, and three conformations per each component, can encode any assembly sequences of a 1D assembly of distinct components with arbitrary length View full abstract»

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  • Programming contact tasks using a reality-based virtual environment integrated with vision

    Publication Year: 1999 , Page(s): 423 - 434
    Cited by:  Papers (22)
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    We present an integrated system in which an operator uses a simulated environment to program part-mating and contact tasks. Generation of models within this virtual environment is facilitated using a fast, occlusion tolerant, 3D grey-scale vision system which can recognize and accurately locate objects within the work site. A major goal of this work is to make robotic programming easy and intuitive for untrained users working with standard desktop hardware. Simulation offers the ease-of-use benefits of “programming by demonstration”, coupled with the ability to create a programmer-friendly virtual environment. Within a simulated environment, it is also straightforward to track and interpret an operator's actions. The simulator models objects as polyhedra and implements full 3D contact dynamics. When a manipulation task is completed, local planning techniques are used to turn the virtual environment's motion sequence history into a set of robot motion commands capable of realizing the prescribed task View full abstract»

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  • End-effector position-orientation measurement

    Publication Year: 1999 , Page(s): 592 - 595
    Cited by:  Papers (1)
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    A low-cost device is presented for noncontact measurement of robot position and orientation. It consists of an optical sensor and three laser scanners. The sensor is attached to the end-effector while the laser scanners cast light planes to trace the sensor movement. The device measures equations of the light planes from which end-effector position and orientation are obtained. Accurate measurement is achieved in a three-DOF experiment View full abstract»

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  • Impact analysis and post-impact motion control issues of a free-floating Space robot subject to a force impulse

    Publication Year: 1999 , Page(s): 548 - 557
    Cited by:  Papers (43)
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    This article presents impact dynamic analysis of a free-floating space robot, subject to a force impulse at the hand. We study the joint and the base reactions in terms of finite velocity changes and clarify their role for the post-impact motion behavior of the robot. The analysis makes use of a joint-space orthogonal decomposition procedure involving the so called reaction null space. The article focuses on the specific case of a nonredundant arm and a reaction null space in terms of base angular motion. We further show that with proper post-impact control it is possible to transfer the whole angular momentum from the base toward the manipulator, and in the same time to reduce the joint velocity View full abstract»

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  • Deadlock avoidance for production systems with flexible routing

    Publication Year: 1999 , Page(s): 497 - 509
    Cited by:  Papers (53)
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    The objective of this work is to characterize the deadlock avoidance problem for systems with flexible routing capabilities. Specifically, the paper addresses deadlock avoidance for single capacity systems (each machine has a single unit of buffer capacity), and mixed capacity systems (some machines have multiple units of buffer capacity). For each of these, we characterize deadlock and prove the correctness of several methods of suboptimal deadlock avoidance. We also address two interesting special cases. The first assumes that every stage of every part type can be performed on at least one multiple capacity machine, whereas the second provides a finite central buffer that can be revisited after every processing stage. For the first case, we present two suboptimal deadlock avoidance approaches, while for the second case, we show optimal deadlock avoidance to be computationally tractable View full abstract»

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  • Path planning using hardware time delays

    Publication Year: 1999 , Page(s): 588 - 592
    Cited by:  Papers (3)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (496 KB)  

    The computation of shortest paths as a basic task in robotics can be accomplished by graph-searching algorithms. Attempts have been made to accelerate a part of these algorithms-the computation of potential vectors-using fine-grained parallel hardware. As shown in this paper, the complexity of digital path-planning circuits can be enormously reduced, if distances are encoded by hardware time delays View full abstract»

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  • Computer vision assisted virtual reality calibration

    Publication Year: 1999 , Page(s): 450 - 464
    Cited by:  Papers (13)  |  Patents (1)
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    A computer vision assisted semi-automatic virtual reality (VR) calibration technology has been developed that can accurately match a virtual environment of graphically simulated 3D models to the video images of the real task environment. We have developed a new 20-variable weighted least-squares algorithm that updates both camera and object models simultaneously for given two camera views of two mating objects. This simultaneous update enables accurate model matching even with rough, approximate initial camera calibrations. The developed semi-automatic VR calibration supports automated intermediate updates, eliminating nearly all operator interaction except for initial coarse matching. In our quasi-static supervisory telerobotic applications, intermediate VR calibrations are performed intermittently at a few robot stopping poses only, as a cost-effective and safer approach compared to real-time visual servoing. Extensive experimental results comparing alignment errors under various viewing conditions are presented View full abstract»

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  • Invited review: the synergy between virtual reality and robotics

    Publication Year: 1999 , Page(s): 400 - 410
    Cited by:  Papers (39)  |  Patents (1)
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    To a large extent the robotics and the newer virtual reality (VR) research communities have been working in isolation. This article reviews three areas where integration of the two technologies can be beneficial. First, we consider VR-enhanced CAD design, robot programming, and plant layout simulation. Subsequently, we discuss how VR is being used in supervisory teleoperation, for single operator-single robot systems, single operator multiplexed to several slave robots, and collaborative control of a single robot by multiple operators. Here VR can help overcome problems related to poor visual feedback as well as system instabilities due to time delays. Finally, we show how robotics can be beneficial to VR in general, since robots can serve as force feedback interfaces to the simulation. Newer back-drivable manipulators offer increased safety for the user that closely interacts with the robot. The synergy between the fields of robotics and virtual reality is expected to grow in years to come View full abstract»

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  • A high integrity IMU/GPS navigation loop for autonomous land vehicle applications

    Publication Year: 1999 , Page(s): 572 - 578
    Cited by:  Papers (119)  |  Patents (3)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (316 KB)  

    This paper describes the development and implementation of a high integrity navigation system, based on the combined use of the Global Positioning System (GPS) and an inertial measurement unit (IMU), for autonomous land vehicle applications. The paper focuses on the issue of achieving the integrity required of the navigation loop for use in autonomous systems. The paper highlights the detection of possible faults both before and during the fusion process in order to enhance the integrity of the navigation loop. The implementation of this fault detection methodology considers both low frequency faults in the IMU caused by bias in the sensor readings and the misalignment of the unit, and high frequency faults from the GPS receiver caused by multipath errors. The implementation, based on a low-cost, strapdown IMU, aided by either standard or carrier phase GPS technologies, is described. Results of the fusion process are presented View full abstract»

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  • Interactive evaluation of assembly sequences using augmented reality

    Publication Year: 1999 , Page(s): 435 - 449
    Cited by:  Papers (21)  |  Patents (1)
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    This paper describes an interactive tool for evaluating assembly sequences using the novel human-computer interface of augmented reality. The goal is to be able to consider various sequencing alternatives of the manufacturing design process by manipulating both virtual and real prototype components. The augmented reality-based assembly evaluation tool would allow a manufacturing engineer to interact with the assembly planner while manipulating the real and virtual prototype components in an assembly environment. Information from the assembly planner can be displayed directly superimposed on the real. A sensing technique is proposed that uses computer vision along with a system of markers for automatically monitoring the assembly state as the user manipulates the assembly components. An implemented system called AREAS is described. The advantage of using mixed prototyping and augmented reality as means of capturing human intuition in assembly planning is also discussed View full abstract»

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  • Heuristics for a tool provisioning problem in a flexible manufacturing system with an automatic tool transporter

    Publication Year: 1999 , Page(s): 488 - 496
    Cited by:  Papers (7)
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    This paper considers a tool provisioning problem in a flexible manufacturing system (FMS) with an automatic tool transporter. The problem considered here is that of determining the number of copies of each tool type for a limited budget with the objective of minimizing makespan. This problem should be solved to decide the (additional) purchase of required tools when the FMS should be reconfigured due to change of part mix. To solve the problem, two heuristic algorithms are proposed. One is a composite search algorithm based on two greedy search methods, and the other is a search algorithm in which numbers of tool copies are determined based on tool groupings. In both algorithms, simulation results are used to find search directions. Computational experiments show that the latter search algorithm gives better results View full abstract»

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  • Assemblability based on maximum likelihood configuration of tolerances

    Publication Year: 1999 , Page(s): 568 - 572
    Cited by:  Papers (2)
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    An assembly is defined by a configuration of parts of known geometries subject to tolerances in the pose, dimensions, and mating relations among part features. Using a tolerance model based on matrix transforms and Gaussian models of geometric variations, the pose and dimensional tolerance models are considered as a priori models of the assembly with nominal and variational components for both position and orientation. The mating relations are regarded as linear relational constraints, also with nominal and variational components. With this formulation, estimation of the configuration of parts may be posed as a maximum likelihood problem and solved by a Kalman filter algorithm. The resulting maximum likelihood configuration of the assembly may be used to evaluate the required deviation from nominal and the assemblability as defined by the maximum likelihood clearance from constraints. In addition, application of the technique to intermediate subassemblies may be used to evaluate assemblability of specific steps and discriminate among alternative assembly sequence plans View full abstract»

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  • Vision guided navigation for a nonholonomic mobile robot

    Publication Year: 1999 , Page(s): 521 - 536
    Cited by:  Papers (76)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (372 KB)  

    Theoretical and analytical aspects of the visual servoing problem have not received much attention. Furthermore, the problem of estimation from the vision measurements has been considered separately from the design of the control strategies. Instead of addressing the pose estimation and control problems separately, we attempt to characterize the types of control tasks which can be achieved using only quantities directly measurable in the image, bypassing the pose estimation phase. We consider the task of navigation for a nonholonomic ground mobile base tracking an arbitrarily shaped continuous ground curve. This tracking problem is formulated as one of controlling the shape of the curve in the image plane. We study the controllability of the system characterizing the dynamics of the image curve, and show that the shape of the image curve is controllable only up to its “linear” curvature parameters. We present stabilizing control laws for tracking piecewise analytic curves, and propose to track arbitrary curves by approximating them by piecewise “linear” curvature curves. Simulation results are given for these control schemes. Observability of the curve dynamics by using direct measurements from vision sensors as the outputs is studied and an extended Kalman filter is proposed to dynamically estimate the image quantities needed for feedback control from the actual noisy images View full abstract»

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  • Sliding mode control for trajectory tracking of nonholonomic wheeled mobile robots

    Publication Year: 1999 , Page(s): 578 - 587
    Cited by:  Papers (138)
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    Nonholonomic mobile robots have constraints imposed on the motion that are not integrable, i.e., the constraints cannot be written as time derivatives of some function of the generalized coordinates. The position control of nonholonomic mobile robots has been an important class of control problems. In this paper, we propose a robust tracking control of nonholonomic wheeled mobile robots using sliding mode. The posture of a mobile robot is represented by polar coordinates and the dynamic equation of the robot is feedback-linearized by the computed-torque method. A novel sliding mode control law is proposed for asymptotically stabilizing the mobile robot to a desired trajectory. It is shown that the proposed scheme is robust to bounded external disturbances. Experimental results demonstrate the effectiveness of accurate tracking capability and the robust performance of the proposed scheme View full abstract»

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  • Kinematic manipulability of general constrained rigid multibody systems

    Publication Year: 1999 , Page(s): 558 - 567
    Cited by:  Papers (25)
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    This paper extends the kinematic manipulability concept commonly used for serial manipulators to general constrained rigid multibody systems. Examples of such systems include multiple cooperating manipulators, multiple fingers holding a payload, multileg walking robots, and variable geometry trusses. Explicit formulas for velocity and force manipulability ellipsoids are derived and their duality explained. Singularities are classified into two types: 1) unmanipulable singularity; 2) unstable singularity. The former is similar the singularities in serial chains where velocity manipulability ellipsoid is degenerate and force manipulability ellipsoid infinite. The latter is unique to parallel mechanisms, the velocity manipulability ellipsoid becomes infinite and force manipulability degenerate. In the case of multifinger grasp, these concepts correspond to unmanipulable or unstable grasps View full abstract»

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  • An architecture for immersive evaluation of complex human tasks

    Publication Year: 1999 , Page(s): 475 - 485
    Cited by:  Papers (3)
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    We investigate how the movement measurement technologies developed for virtual reality applications can be applied to track in real-time the full body posture of a human being. The accuracy of this information is of definite importance to evaluate the feasibility of complex tasks involving human beings. We present a full body movement measurement approach. It provides a realistic conversion in real-time with a reasonable number of sensors. Associated with the hand movement measurement and correction algorithms we provide a pertinent visual and vibrotactile feedback to the performer View full abstract»

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  • Runway obstacle detection by controlled spatiotemporal image flow disparity

    Publication Year: 1999 , Page(s): 537 - 547
    Cited by:  Papers (2)  |  Patents (1)
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    This paper proposes a method for detecting obstacles on a runway by controlling their expected flow disparities. The runway is modeled as a planar surface. By approximating the runway by a planar surface, the initial model flow field (MFF) corresponding to an obstacle-free runway is described by the data from on-board sensors (OBS). The initial residual flow field (RFF) is obtained after warping (or stabilizing) the image using the initial MFF. The error variance of the initial MFF is estimated. The initial RFF and the error variance are first used to identify the pixels corresponding to the obstacle-free runway and then to noniteratively estimate the MFF and RFF. Obstacles are detected by comparing the expected residual flow disparities with the RFF. Expected temporal and spatial residual disparities are obtained from the use of the OBS. This allows us to control the residual disparities by increasing the temporal baseline and/or by utilizing the spatial baseline if distant objects cannot be detected for a given temporal baseline. Experimental results for two real flight image sequences are presented View full abstract»

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  • Projective virtual reality: bridging the gap between virtual reality and robotics

    Publication Year: 1999 , Page(s): 411 - 422
    Cited by:  Papers (16)
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    The new paradigm of projective virtual reality is presented as a sophisticated new approach to the control and supervision of robotic and automation systems. The idea behind projective virtual reality is to “project” actions that are carried out by users in the virtual world into the real world, primarily by means of robots but also by other means of automation. Robot control technology thus provides the user in the virtual reality with a “prolonged arm” into the physical environment, paving the way for a new quality of a user friendly man machine interface for automation applications. The paper provides the background of projective virtual reality which is based on latest results in the fields of task planning, world modeling, cooperative robot control and sensor-based robot control View full abstract»

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Aims & Scope

This Transactions ceased production in 2004. The current retitled publications areIEEE Transactions on Automation Science and Engineering and IEEE Transactions on Robotics.

Full Aims & Scope