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Robotics, IEEE Transactions on

Issue 2 • Date April 2011

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Displaying Results 1 - 21 of 21
  • Table of contents

    Publication Year: 2011 , Page(s): C1
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  • IEEE Transactions on Robotics publication information

    Publication Year: 2011 , Page(s): C2
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  • Kinematic Modeling of Bird Locomotion from Experimental Data

    Publication Year: 2011 , Page(s): 185 - 200
    Cited by:  Papers (3)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (1813 KB) |  | HTML iconHTML  

    We present the design of a bird-like kinematics model for a biped robot as an alternative to the human model. The starting point of the research consists of analyzing the walking motion of quail birds using biological data obtained by X-ray radiography. The 3-D-motion analysis allows identification of the number of degrees of freedom (DOF) and the rotation mechanism for each leg, especially the main rotation axis. Leg joints are located at the hip, knee, ankle, and foot. The ankle is off the ground. Using this analysis, we have designed a biped kinematics model with a minimum of actuated joints and with the original orientation of hip and ankle main rotary joints, which are not horizontally and vertically oriented as in classical biped robotics. Given a reference-foot trajectory, we carry out simulations to compare internal-joint trajectories with the ones obtained from biological measurements. We show that the proposed model can be used to reproduce the kinematics of bird locomotion with a minimum of four actuated joints per leg, i.e., two at the hip and one at the knee, and one at the ankle, which is less than the usual six joints per leg that drive anthropomorphic legs. View full abstract»

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  • Haptic Device Using a Newly Developed Redundant Parallel Mechanism

    Publication Year: 2011 , Page(s): 201 - 214
    Cited by:  Papers (1)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (1832 KB) |  | HTML iconHTML  

    A number of haptic devices have recently become available on the commercial market, and these devices are becoming common not only in research but in consumer use as well. In this paper, a new parallel mechanism, referred to herein as DELTA-R (meaning DELTA-Redundant, formerly referred to as DELTA-4) is proposed for a new haptic device having high-quality force display capability and operability. DELTA-R allows three-degree-of-freedom (DOF) translational motions. The key features of DELTA-R, as compared with conventional parallel mechanisms, are redundant actuation, a smaller footprint, a larger working area, and improved access to the end effector. The prototype is equipped with a 3-DOF rotation mechanism, the center of motion of which is located on the wrist position of the operator. An evaluation test of the force display was conducted using a prototype of the proposed mechanism. This paper describes the kinematic design, kinematic modeling, kinematic analysis, prototype implementation, and evaluations. View full abstract»

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  • Recursive Inverse Dynamics of Mobile Multibody Systems With Joints and Wheels

    Publication Year: 2011 , Page(s): 215 - 228
    Cited by:  Papers (3)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (844 KB) |  | HTML iconHTML  

    This paper is related to the inverse-dynamic modeling of mobile multibody systems articulated with joints and wheels. An easily-implementable algorithm, which is based on Newton-Euler (NE) recursive dynamics, is proposed. From imposed joint and/or actuated-wheel motions, the algorithm performs fast calculations of the control torques, as well as the overall rigid motions involved in locomotion tasks. The engineering applications include tree-like mobile manipulators, satellite-reorientation systems, and modular robots, such as snake-like robots, eel-like robots, and a snakeboard. View full abstract»

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  • A Robot Joint With Variable Stiffness Using Leaf Springs

    Publication Year: 2011 , Page(s): 229 - 238
    Cited by:  Papers (18)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (1029 KB) |  | HTML iconHTML  

    Interaction with humans is inevitable for service robots, which results in safety being one of the most important factors in designing the robots. Compliant component is an answer to the safety issue at the cost of performance degradation. In order to reduce the performance degradation, manipulators equipped with variable stiffness have been studied by many researchers. This paper presents a variable stiffness joint (VSJ) designed for a robot manipulator, as well as a control scheme to control the stiffness and position of the VSJ. Compliance is generated by leaf springs and two actuators are used to control the position and stiffness of the joint using four-bar linkages. Two actuators in parallel configuration are connected to the spring. Changing the effective length of the spring results in a change in stiffness. The position of the joint is controlled via two actuators rotating at the same speed in the same direction. A nonlinear controller is used to control the VSJ, and a singular perturbation model is adopted to prove the stability of the closed-loop system. Experiments are conducted to show that the position and stiffness are controlled independent of each other, and having less stiffness at the joint helps in making an unexpected collision with an object safer. View full abstract»

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  • State Estimation Based on the Concept of Continuous Symmetry and Observability Analysis: The Case of Calibration

    Publication Year: 2011 , Page(s): 239 - 255
    Cited by:  Papers (12)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (1000 KB) |  | HTML iconHTML  

    This paper considers the problem of state estimation in autonomous navigation from a theoretical perspective. In particular, the investigation concerns problems where the information provided by the sensor data is not sufficient to carry out the state estimation (i.e., the state is not observable). For these systems, the concept of continuous symmetry is introduced. Detection of the continuous symmetries of a given system has a very practical importance. It allows the detection of an observable state whose components are nonlinear functions of the original nonobservable state. So far, this theoretical and very general concept has been applied to deal with two distinct fundamental estimation problems in the framework of mobile robotics. The former is in the framework of self-calibration, and the latter is in the framework of the fusion of the data provided by inertial sensors and vision sensors. For reasons of length, only the former is discussed. In particular, the theoretical machinery is used to address a specific calibration problem. The solution constrains the robot to move along specific trajectories in order to be able to apply the calibration algorithm. This paper provides two distinct contributions. The first is the introduction of this concept of continuous symmetry. The second is the introduction of a simple and efficient strategy to extrinsically calibrate a bearing sensor (e.g., a vision sensor) mounted on a vehicle and, simultaneously, estimate the parameters describing the systematic error of its odometry system. Many accurate simulations and real experiments show the robustness, the efficiency, and the accuracy of the proposed strategy. View full abstract»

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  • Distance-Based and Orientation-Based Visual Servoing From Three Points

    Publication Year: 2011 , Page(s): 256 - 267
    Cited by:  Papers (7)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (1254 KB) |  | HTML iconHTML  

    This paper is concerned with the use of a spherical-projection model for visual servoing from three points. We propose a new set of six features to control a 6-degree-of-freedom (DOF) robotic system with good decoupling properties. The first part of the set consists of three invariants to camera rotations. These invariants are built using the Cartesian distances between the spherical projections of the three points. The second part of the set corresponds to the angle-axis representation of a rotation matrix measured from the image of two points. Regarding the theoretical comparison with the classical perspective coordinates of points, the new set does not present more singularities. In addition, using the new set inside its nonsingular domain, a classical control law is proven to be optimal for pure rotational motions. The theoretical results and the robustness to points range errors of the new control scheme are validated through simulations and experiments on a 6-DOF robot arm. View full abstract»

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  • A Random-Finite-Set Approach to Bayesian SLAM

    Publication Year: 2011 , Page(s): 268 - 282
    Cited by:  Papers (31)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (1422 KB) |  | HTML iconHTML  

    This paper proposes an integrated Bayesian frame work for feature-based simultaneous localization and map building (SLAM) in the general case of uncertain feature number and data association. By modeling the measurements and feature map as random finite sets (RFSs), a formulation of the feature-based SLAM problem is presented that jointly estimates the number and location of the features, as well as the vehicle trajectory. More concisely, the joint posterior distribution of the set-valued map and vehicle trajectory is propagated forward in time as measurements arrive, thereby incorporating both data association and feature management into a single recursion. Furthermore, the Bayes optimality of the proposed approach is established. A first-order solution, which is coined as the probability hypothesis density (PHD) SLAM filter, is derived, which jointly propagates the posterior PHD of the map and the posterior distribution of the vehicle trajectory. A Rao-Blackwellized (RB) implementation of the PHD-SLAM filter is proposed based on the Gaussian-mixture PHD filter (for the map) and a particle filter (for the vehicle trajectory). Simulated and experimental results demonstrate the merits of the proposed approach, particularly in situations of high clutter and data association ambiguity. View full abstract»

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  • Conflict Resolution in Free-Ranging Multivehicle Systems: A Resource Allocation Paradigm

    Publication Year: 2011 , Page(s): 283 - 296
    Cited by:  Papers (11)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (1089 KB) |  | HTML iconHTML  

    We propose a novel paradigm for conflict resolution in multivehicle traffic systems, where a number of mobile agents move freely in a finite area, with each agent following a prespecified-motion profile. The key idea behind the proposed method is the tessellation of the underlying motion area in a number of cells and the treatment of these cells as resources that must be acquired by the mobile agents for the execution of their motion profiles, according to an appropriate resource allocation protocol. We capitalize upon the existing literature on the real-time management of sequential resource allocation systems (RASs) and develop such protocols that can formally guarantee the safe and live operation of the underlying traffic system, while they remain scalable with respect to the number of the moving agents. Collective past experience with the considered policies indicates that they also provide a pretty large coverage of the RAS behavioral space that characterizes its safe and live operation. Finally, we also establish that the aforementioned approach is applicable even in traffic systems where all vehicles must be in perpetual motion until their retirement. View full abstract»

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  • A Minimalist Algorithm for Multirobot Continuous Coverage

    Publication Year: 2011 , Page(s): 297 - 312
    Cited by:  Papers (5)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (1270 KB) |  | HTML iconHTML  

    This paper describes an algorithm, which has been specifically designed to solve the problem of multirobot-controlled frequency coverage (MRCFC), in which a team of robots are requested to repeatedly visit a set of predefined locations of the environment according to a specified frequency distribution. The algorithm has low requirements in terms of computational power, does not require inter-robot communication, and can even be implemented on memoryless robots. Moreover, it has proven to be statistically complete as well as easily implementable on real, marketable robot swarms for real-world applications. View full abstract»

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  • On the Time to Search for an Intermittent Signal Source Under a Limited Sensing Range

    Publication Year: 2011 , Page(s): 313 - 323
    Cited by:  Papers (4)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (838 KB) |  | HTML iconHTML  

    A mobile robot with a limited sensing range is deployed to search for a stationary target that intermittently emits short duration signals. The searching mission is accomplished as soon as the robot receives a signal from the target. We propose the expected searching time (EST) as a primary metric to evaluate different robot motion plans under different robot configurations. To illustrate the proposed metric, we present two case studies. In the first case, we analyze two common motion plans: a slap method (SM) and a random walk (RW). The EST analysis shows that the SM is asymptotically faster than the RW when the searching space size increases. In the second case, we compare a team of n homogeneous low-cost robots with a super robot that has the sensing range equal to that of the summation of the n robots. Our analysis shows that the low-cost robot team takes Θ(1/n) time, while the super robot takes Θ(1/√n) time as n → ∞. Our metrics successfully demonstrate their ability in assessing the searching performance. The analytical results are also confirmed in simulation and physical experiments. View full abstract»

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  • Two-Finger Caging of Nonconvex Polytopes

    Publication Year: 2011 , Page(s): 324 - 333
    Cited by:  Papers (7)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (676 KB) |  | HTML iconHTML  

    In general, any object can be restricted or caged within a bounded region if we evenly place a sufficient number of fingers around the object. This naive approach often leads to inefficient utilization of fingers because only two fingers are sufficient to cage most nonconvex objects. In this paper, we propose an algorithm that identifies all the caging sets, i.e., set of two-finger placements that cage a given polytope representing the object. Whether a finger placement could cage the object can be queried efficiently from a structure generated by the algorithm. We implemented and tested the algorithm in the case of 2-D and 3-D objects. View full abstract»

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  • Stiffness Control of Surgical Continuum Manipulators

    Publication Year: 2011 , Page(s): 334 - 345
    Cited by:  Papers (21)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (870 KB) |  | HTML iconHTML  

    This paper introduces the first stiffness controller for continuum robots. The control law is based on an accurate approximation of a continuum robot's coupled kinematic and static force model. To implement a desired tip stiffness, the controller drives the actuators to positions corresponding to a deflected robot configuration that produces the required tip force for the measured tip position. This approach provides several important advantages. First, it enables the use of robot deflection sensing as a means to both sense and control tip forces. Second, it enables stiffness control to be implemented by modification of existing continuum robot position controllers. The proposed controller is demonstrated experimentally in the context of a concentric tube robot. Results show that the stiffness controller achieves the desired stiffness in steady state, provides good dynamic performance, and exhibits stability during contact transitions. View full abstract»

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  • Robotic Assistance to Flexible Endoscopy by Physiological-Motion Tracking

    Publication Year: 2011 , Page(s): 346 - 359
    Cited by:  Papers (9)
    Multimedia
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (1504 KB)  

    Flexible endoscopes are used in many diagnostic exams, like gastroscopies or colonoscopies, as well as for small surgical procedures. Recently, they have also been used for endoscopic surgical procedures through natural orifices [natural orifice transluminal endoscopic surgery (NOTES)] and for single-port-access abdominal surgery (SPA). Indeed, flexible endoscopes allow access of operating areas that are not easily reachable with only one small external or internal incision. However, their manipulation is complex, especially for surgical interventions. This study proposes to motorize the flexible endoscope and to partly robotize its movements in order to help the physicians during such interventions. The paper explains how the robotized endoscope can be used to automatically track an area of interest despite breathing motion. The system uses visual servoing and repetitive control strategies and allows stabilization of the endoscopic view. All required parameters are automatically estimated. In vivo experiments show the validity of the proposed solution for the improvement of the manipulation of flexible endoscopes. View full abstract»

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  • DTAR—A Dynamic, Tube-Ascending Robot

    Publication Year: 2011 , Page(s): 360 - 364
    Multimedia
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (659 KB)  

    This paper investigates a novel minimalistic mechanism that ascends tubes. The mechanism is comprised of only a rigid body, two O-rings, and a motor rotating an eccentric mass. We describe the underlying locomotion principle of rocking and jamming, without the use of special bristles or spines, and demonstrate the robustness of this mechanism. View full abstract»

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  • A Little More, a Lot Better: Improving Path Quality by a Path-Merging Algorithm

    Publication Year: 2011 , Page(s): 365 - 371
    Cited by:  Papers (10)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (885 KB) |  | HTML iconHTML  

    Sampling-based motion planners are an effective means to generate collision-free motion paths. However, the quality of these motion paths (with respect to quality measures, such as path length, clearance, smoothness, or energy) is often notoriously low, especially in high-dimensional configuration spaces. We introduce a simple algorithm to merge an arbitrary number of input motion paths into a hybrid output path of superior quality, for a broad and general formulation of path quality. Our approach is based on the observation that the quality of certain subpaths within each solution may be higher than the quality of the entire path. A dynamic-programming algorithm, which we recently developed to compare and cluster multiple motion paths, reduces the running time of the merging algorithm significantly. We tested our algorithm in motion-planning problems with up to 12 degrees of freedom (DOFs), where our method is shown to be particularly effective. We show that our algorithm is able to merge a handful of input paths produced by several different motion planners to produce output paths of much higher quality. View full abstract»

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  • Improved Stability Results for Visual Tracking of Robotic Manipulators Based on the Depth-Independent Interaction Matrix

    Publication Year: 2011 , Page(s): 371 - 379
    Cited by:  Papers (2)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (777 KB) |  | HTML iconHTML  

    As we know, the dynamic visual-tracking control, which is based on the depth-independent interaction matrix, has been proposed to cope with the general 3-D motion of robot manipulators. To deal with the unknown camera parameters, an adaptive law has been designed. It is noted, however, that the designed adaptive law uses a vector signal defined by the true depths of feature points, which are unavailable when the camera parameters are unknown. Nevertheless, such an adaptive law can still be implemented by replacing the exact depths with the estimated depths, since the estimated depths can be readily calculated by using the estimated values of the camera parameters. In this case, however, we cannot definitely say whether or not the robot system can be guaranteed to achieve asymptotical stability or even stable behavior. To overcome this problem, in this paper, we redefine the mentioned vector signal using the estimated depths and show that the design based on the new vector signal can make the robot system asymptotically stable. Additionally, the existing tracking control design based on the concept of depth-independent interaction matrix is initial-state dependent. Thus, in this paper, we also modify the existing design to obtain an initial-state-independent result. To show the performance of the proposed designs, simulation results based on a two-link planar manipulator are presented. In addition, preliminary experimental results using an industrial manipulator are also given. View full abstract»

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  • A New Aerodynamic-Traction Principle for Handling Products on an Air Cushion

    Publication Year: 2011 , Page(s): 379 - 384
    Cited by:  Papers (3)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (792 KB) |  | HTML iconHTML  

    This paper introduces a new aerodynamic-traction principle to handle delicate and clean products, such as silicon wafers, glass sheets, or flat foodstuffs. The product is carried on a thin air cushion and transported along the system by induced airflows. This induced airflow is an indirect effect of strong vertical air jets that pull the surrounding fluid. This paper provides a qualitative explanation of the operating principles and a description of the experimental device. First experimental results with active control are presented. The maximum velocity and acceleration that can be obtained for the considered device geometry meet the requirements for industrial applications. View full abstract»

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  • IEEE Robotics and Automation Society Information

    Publication Year: 2011 , Page(s): C3
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    Freely Available from IEEE
  • IEEE Transactions on Robotics Information for authors

    Publication Year: 2011 , Page(s): C4
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    Freely Available from IEEE

Aims & Scope

IEEE Transactions on Robotics covers both theory and applications on topics including: kinematics, dynamics, control, and simulation of robots and intelligent machines and systems.

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Meet Our Editors

Editor-in-Chief
Frank Park
Seoul National University