By Topic

Robotics, IEEE Transactions on

Issue 1 • Date Feb. 2008

Filter Results

Displaying Results 1 - 25 of 29
  • Table of contents

    Publication Year: 2008 , Page(s): C1
    Save to Project icon | Request Permissions | PDF file iconPDF (36 KB)  
    Freely Available from IEEE
  • IEEE Transactions on Robotics publication information

    Publication Year: 2008 , Page(s): C2
    Save to Project icon | Request Permissions | PDF file iconPDF (37 KB)  
    Freely Available from IEEE
  • Editorial

    Publication Year: 2008 , Page(s): 1 - 2
    Save to Project icon | Request Permissions | PDF file iconPDF (31 KB)  
    Freely Available from IEEE
  • Guest Editorial Special Issue on Biorobotics

    Publication Year: 2008 , Page(s): 3 - 4
    Cited by:  Papers (1)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (30 KB)  

    The focus of this special issue is to show how the main achievements on different technical topics relevant to the development of bioinspired and bioapplied mechatronic devices and robotic systems. The 19 articles in this special issue are summarized here. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • An Optimality Principle Governing Human Walking

    Publication Year: 2008 , Page(s): 5 - 14
    Cited by:  Papers (36)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (662 KB) |  | HTML iconHTML  

    In this paper, we investigate different possible strategies underlying the formation of human locomotor trajectories in goal-directed walking. Seven subjects were asked to walk within a motion capture facility from a fixed starting point and direction, and to cross over distant porches for which both position and direction in the room were changed over trials. Stereotyped trajectories were observed in the different subjects. The underlying idea to attack this question has been to relate this problem to an optimal control scheme: the trajectory is chosen according to some optimization principle. This is our basic starting assumption. The subject being viewed as a controlled system, we tried to identify several criteria that could be optimized. Is it the time to perform the trajectory? The length of the path? The minimum jerk along the path? We found that the variation (time derivative) of the curvature of the locomotor paths is minimized. Moreover, we show that the human locomotor trajectories are well approximated by the geodesics of a differential system minimizing the norm of the control. Such geodesics are made of arcs of clothoids. The clothoid or Cornu spiral is a curve, whose curvature grows with the distance from the origin. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Learning Object Affordances: From Sensory--Motor Coordination to Imitation

    Publication Year: 2008 , Page(s): 15 - 26
    Cited by:  Papers (74)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (904 KB) |  | HTML iconHTML  

    Affordances encode relationships between actions, objects, and effects. They play an important role on basic cognitive capabilities such as prediction and planning. We address the problem of learning affordances through the interaction of a robot with the environment, a key step to understand the world properties and develop social skills. We present a general model for learning object affordances using Bayesian networks integrated within a general developmental architecture for social robots. Since learning is based on a probabilistic model, the approach is able to deal with uncertainty, redundancy, and irrelevant information. We demonstrate successful learning in the real world by having an humanoid robot interacting with objects. We illustrate the benefits of the acquired knowledge in imitation games. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Models for the Design of Bioinspired Robot Eyes

    Publication Year: 2008 , Page(s): 27 - 44
    Cited by:  Papers (10)
    Multimedia
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (1065 KB) |  | HTML iconHTML  

    Active vision has the goal of improving visual perception; therefore, the investigation of ocular motion strategies must play an important role in the design of humanoid robot eyes. Listing's law is a basic principle, which characterizes various ocular movements in humans, including saccades and smooth pursuit, and its neural or mechanical origin has been debated for a long time. Recent anatomical advances suggest that motions compatible with Listing's law could be mainly caused by the mechanical structure of the eye plant. In this paper, we present a bioinspired model of the eye plant, and we formally prove that according to the model, the implementation of Listing's law can be actually explained on the base of the geometry of the eye and of its actuation system. The proposed model is characterized by a limited number of geometric parameters, which can be easily used to set the guidelines for the design of humanoid, and possibly tendon-driven, robot eyes. Simulative and experimental tests performed on a robot prototype are eventually presented to perform a quantitative evaluation of the performance of the model, also in comparison with physiological data measured in humans and primates and reported in the literature. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Image Stabilization for In Vivo Microscopy by High-Speed Visual Feedback Control

    Publication Year: 2008 , Page(s): 45 - 54
    Cited by:  Papers (8)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (842 KB) |  | HTML iconHTML  

    This paper presents image stabilization for microscopy using horizontal visual feedback control of the objective lens through a five-bar linkage and piezoelectric actuators, and its application to in vivo imaging. Even very small in vivo motion due to heartbeat and breathing makes microscopic observation difficult by blurring the microscope image or impossible by sending a region of interest out of view. In order to remove those unwanted effects of the motion, we have introduced motion-canceling robotic technologies into microscopy. Our image stabilization system through motion-canceling provides users with stabilized image sequences with respect to trembling of in vivo subjects. The developed image stabilization system, in term of robotics, corresponds to a visual feedback control system that consists of a robotic mechanism and a high-speed vision. A high-speed camera installed in the microscope detects the motion of the in vivo subject having topically applied fiducials. To virtually cancel this motion, we move the objective lens, synchronizing the motions of the subject and the lens to remove the relative motion between the two. As a result, we observe motion-free images to m. This technology is one of the very demanding technologies in biological research for in vivo observation with high resolution. In this paper, we verify the effectiveness of the developed system through in vivo experiments. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Bioinspired Robotic Dual-Camera System for High-Resolution Vision

    Publication Year: 2008 , Page(s): 55 - 64
    Cited by:  Papers (1)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (889 KB) |  | HTML iconHTML  

    Due to the limited resolution of both cameras and displays, acuity of artificial vision systems is currently well below the human eye. Visual acuity, in cameras as well as in animal eyes, can be increased by making smaller receptors or bigger eyes. In some applications, the size of the camera is constrained, so alternative solutions must be sought. This paper presents a robotic dual-camera vision system whose design is inspired by the visual system of jumping spiders (Salticidae family). The system is composed of a telephoto camera whose field of view (FOV) can be moved within the larger FOV of a wide-angle camera and allows to form a high-resolution image, i.e., an image with the FOV of the wide-angle camera, yet having the same resolution as the telephoto camera. We describe the design of the robotic system, the direct and inverse kinematics, and the image processing algorithms that allow to build the high-resolution image. Images from experiments are presented, together with a discussion on sources of errors and possible solutions. The system is particularly useful for fixed-camera monitoring or teleoperation applications, such as remote surveillance and minimally invasive surgery. The system achieves seven times higher resolution than typical commercial endoscopes. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Smooth Vertical Surface Climbing With Directional Adhesion

    Publication Year: 2008 , Page(s): 65 - 74
    Cited by:  Papers (92)  |  Patents (1)
    Multimedia
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (1243 KB)  

    Stickybot is a bioinspired robot that climbs smooth vertical surfaces such as glass, plastic, and ceramic tile at 4 cm/s. The robot employs several design principles adapted from the gecko including a hierarchy of compliant structures, directional adhesion, and control of tangential contact forces to achieve control of adhesion. We describe the design and fabrication methods used to create underactuated, multimaterial structures that conform to surfaces over a range of length scales from centimeters to micrometers. At the finest scale, the undersides of Stickybot's toes are covered with arrays of small, angled polymer stalks. Like the directional adhesive structures used by geckos, they readily adhere when pulled tangentially from the tips of the toes toward the ankles; when pulled in the opposite direction, they release. Working in combination with the compliant structures and directional adhesion is a force control strategy that balances forces among the feet and promotes smooth attachment and detachment of the toes. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Online Optimization of Swimming and Crawling in an Amphibious Snake Robot

    Publication Year: 2008 , Page(s): 75 - 87
    Cited by:  Papers (48)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (922 KB) |  | HTML iconHTML  

    An important problem in the control of locomotion of robots with multiple degrees of freedom (e.g., biomimetic robots) is to adapt the locomotor patterns to the properties of the environment. This article addresses this problem for the locomotion of an amphibious snake robot, and aims at identifying fast swimming and crawling gaits for a variety of environments. Our approach uses a locomotion controller based on the biological concept of central pattern generators (CPGs) together with a gradient-free optimization method, Powell's method. A key aspect of our approach is that the gaits are optimized online, i.e., while moving, rather than as an off-line optimization process. We present various experiments with the real robot and in simulation: swimming, crawling on horizontal ground, and crawling on slopes. For each of these different situations, the optimized gaits are compared with the results of systematic explorations of the parameter space. The main outcomes of the experiments are: 1) optimal gaits are significantly different from one medium to the other; 2) the optimums are usually peaked, i.e., speed rapidly becomes suboptimal when the parameters are moved away from the optimal values; 3) our approach finds optimal gaits in much fewer iterations than the systematic search; and 4) the CPG has no problem dealing with the abrupt parameter changes during the optimization process. The relevance for robotic locomotion control is discussed. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Snake Robot Obstacle-Aided Locomotion: Modeling, Simulations, and Experiments

    Publication Year: 2008 , Page(s): 88 - 104
    Cited by:  Papers (46)
    Multimedia
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (796 KB)  

    Snakes utilize irregularities in the terrain, such as rocks and vegetation, for faster and more efficient locomotion. This motivates the development of snake robots that actively use the terrain for locomotion, i.e., obstacle-aided locomotion. In order to accurately model and understand this phenomenon, this paper presents a novel nonsmooth (hybrid) mathematical model for wheel-less snake robots, which allows the snake robot to push against external obstacles apart from a flat ground. The framework of nonsmooth dynamics and convex analysis allows us to systematically and accurately incorporate both unilateral contact forces (from the obstacles) and isotropic friction forces based on Coulomb's law using set-valued force laws. The mathematical model is verified through experiments. In particular, a back-to-back comparison between numerical simulations and experimental results is presented. It is, furthermore, shown that the snake robot is able to move forward faster and more robustly by exploiting obstacles. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Microautonomous Robotic Ostraciiform (MARCO): Hydrodynamics, Design, and Fabrication

    Publication Year: 2008 , Page(s): 105 - 117
    Cited by:  Papers (11)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (1463 KB) |  | HTML iconHTML  

    Boxfish with multiple fins can maneuver in confined spaces with a near zero turning radius, and it has been found that its unusual boxy shape is responsible for a self-correcting mechanism that makes its trajectories immune to water disturbances. The microautonomous robotic ostraciiform aims to apply these features in a novel underwater vehicle design. Miniature underwater vehicles with these characteristics have a variety of applications, such as environmental monitoring, ship wreck exploration, inline pipe inspection, forming sensor networks, etc. This paper presents the research leading to the design and fabrication of a robotic ostraciiform. Tail fin hydrodynamics have been investigated experimentally using robotic flapper mechanisms to arrive at a caudal fin shape with optimal-shape-induced flexibility. Fluid simulation studies were utilized to arrive at the body shape that can result in a self-correcting vorticity generation. Finally, the robotic ostraciiform prototype was designed based on the previous results. The ostracifform locomotion is implemented with a pair of 2 DOF pectoral fins and a single DOF tail fin. The finalized body shape of the robot is produced by 3-D prototyping two separate halves. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Electrostatically Actuated Robotic Fish: Design and Control for High-Mobility Open-Loop Swimming

    Publication Year: 2008 , Page(s): 118 - 129
    Cited by:  Papers (14)
    Multimedia
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (1119 KB)  

    This paper presents a project that aims at fabricating a biologically inspired robotic fish. The robotic fish is designed to be capable of propelling itself through oscillations of a flexible caudal fin, like a real underwater fish. In this paper, we describe the design features that underlie the operation of the robotic fish. These features include a unique actuator referred to as electrostatic film motor and a light and flexible power transmission system. The electrostatic film motor is made of two pieces of flexible printed circuit film and can be utilized as a new-type artificial muscle. The power transmission system permits reciprocating power to be converted to periodic oscillations and distributed to the caudal fin. Based on several design considerations inspired by biological concepts, we propose several open-loop swimming control strategies for the constructed robotic fish to accomplish fish-like motion (i.e., cruising, turning, and diving). Experiments of Seidengyo I, the first prototype of our electrostatic fish family, are carried out to confirm the validity of the original design and control. We further design Seidengyo II to improve on Seidengyo I and show the results of the experiments. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Templates and Anchors for Antenna-Based Wall Following in Cockroaches and Robots

    Publication Year: 2008 , Page(s): 130 - 143
    Cited by:  Papers (14)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (909 KB)  

    The interplay between robotics and neuromechanics facilitates discoveries in both fields: nature provides roboticists with design ideas, while robotics research elucidates critical features that confer performance advantages to biological systems. Here, we explore a system particularly well suited to exploit the synergies between biology and robotics: high-speed antenna-based wall following of the American cockroach (Periplaneta americana). Our approach integrates mathematical and hardware modeling with behavioral and neurophysiological experiments. Specifically, we corroborate a prediction from a previously reported wall-following template - the simplest model that captures a behavior - that a cockroach antenna-based controller requires the rate of approach to a wall in addition to distance, e.g., in the form of a proportional-derivative (PD) controller. Neurophysiological experiments reveal that important features of the wall-following controller emerge at the earliest stages of sensory processing, namely in the antennal nerve. Furthermore, we embed the template in a robotic platform outfitted with a bio-inspired antenna. Using this system, we successfully test specific PD gains (up to a scale) fitted to the cockroach behavioral data in a "real-world" setting, lending further credence to the surprisingly simple notion that a cockroach might implement a PD controller for wall following. Finally, we embed the template in a simulated lateral-leg-spring (LLS) model using the center of pressure as the control input. Importantly, the same PD gains fitted to cockroach behavior also stabilize wall following for the LLS model. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Lower Extremity Exoskeletons and Active Orthoses: Challenges and State-of-the-Art

    Publication Year: 2008 , Page(s): 144 - 158
    Cited by:  Papers (121)  |  Patents (3)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (791 KB) |  | HTML iconHTML  

    In the nearly six decades since researchers began to explore methods of creating them, exoskeletons have progressed from the stuff of science fiction to nearly commercialized products. While there are still many challenges associated with exoskeleton development that have yet to be perfected, the advances in the field have been enormous. In this paper, we review the history and discuss the state-of-the-art of lower limb exoskeletons and active orthoses. We provide a design overview of hardware, actuation, sensory, and control systems for most of the devices that have been described in the literature, and end with a discussion of the major advances that have been made and hurdles yet to be overcome. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • A Gas-Actuated Anthropomorphic Prosthesis for Transhumeral Amputees

    Publication Year: 2008 , Page(s): 159 - 169
    Cited by:  Papers (14)
    Multimedia
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (1572 KB)  

    This paper presents the design of a gas-actuated anthropomorphic arm prosthesis with 21 degrees of freedom and nine independent actuators. The prosthesis utilizes the monopropellant hydrogen peroxide as a gas generator to power nine pneumatic type actuators. Of the nine independent actuators, one provides direct- drive actuation of the elbow, three provide direct-drive actuation for the wrist, and the remaining five actuate an underactuated 17 degree of freedom hand. This paper describes the design of the prosthesis, including the design of small-scale high-performance servovalves, which enable the implementation of the monopropellant concept in a transhumeral prosthesis. Experimental results are given characterizing both the servovalve performance and the force and/or motion control of various joints under closed-loop control. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • On the Shared Control of an EMG-Controlled Prosthetic Hand: Analysis of User–Prosthesis Interaction

    Publication Year: 2008 , Page(s): 170 - 184
    Cited by:  Papers (83)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (1384 KB) |  | HTML iconHTML  

    An anthropomorphic underactuated prosthetic hand, endowed with position and force sensors and controlled by means of myoelectric commands, is used to perform experiments of hierarchical shared control. Three different hierarchical control strategies combined with a vibrotactile feedback system have been developed and tested by able-bodied subjects through grasping tasks used in activities of daily living (ADLs). The first goal is to find a good tradeoff between good grasping capabilities and low attention required by the user to complete grasping tasks, without addressing advanced algorithm for electromyographic processing. The second goal is to understand whether a vibrotactile feedback system is subjectively or objectively useful and how it changes users' performance. Experiments showed that users were able to successfully operate the device in the three control strategies, and that the grasp success increased with more interactive control. Practice has proven that when too much effort is required, subjects do not do their best, preferring, instead, a less-interactive control strategy. Moreover, the experiments showed that when grasping tasks are performed under visual control, the enhanced proprioception offered by a vibrotactile system is practically not exploited. Nevertheless, in subjective opinion, feedback seems to be quite important. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • A Biologically Inspired Biped Locomotion Strategy for Humanoid Robots: Modulation of Sinusoidal Patterns by a Coupled Oscillator Model

    Publication Year: 2008 , Page(s): 185 - 191
    Cited by:  Papers (29)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (832 KB) |  | HTML iconHTML  

    Biological systems seem to have a simpler but more robust locomotion strategy than that of the existing biped walking controllers for humanoid robots. We show that a humanoid robot can step and walk using simple sinusoidal desired joint trajectories with their phase adjusted by a coupled oscillator model. We use the center-of-pressure location and velocity to detect the phase of the lateral robot dynamics. This phase information is used to modulate the desired joint trajectories. We do not explicitly use dynamical parameters of the humanoid robot. We hypothesize that a similar mechanism may exist in biological systems. We applied the proposed biologically inspired control strategy to our newly developed human-sized humanoid robot computational brain (CB) and a small size humanoid robot, enabling them to generate successful stepping and walking patterns. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Multisensor Input for CPG-Based Sensory---Motor Coordination

    Publication Year: 2008 , Page(s): 191 - 195
    Cited by:  Papers (15)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (387 KB) |  | HTML iconHTML  

    This paper describes a method for providing in real time a reliable synchronization signal for cyclical motions such as steady-state walking. The approach consists in estimating online a phase variable on the basis of several implicit central pattern generator associated with a set of sensors. These sensors can be of any kind, provided their output strongly reflects the timed motion of a link. They can be, for example, spatial position or orientation sensors, or foot sole pressure sensors. The principle of the method is to use their outputs as inputs to nonlinear observers of modified Van der Pol oscillators that provide us with several independent estimations of the overall phase of the system. These estimations are then combined within a dynamical filter constituted of a Hopf oscillator. The resulting phase is a reliable indexing of the cyclic behavior of the system, which can finally be used as input to low-level controllers of a robot. Some results illustrate the efficiency of the approach, which can be used to control robots. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Effectiveness of Insect-Inspired Chemical Plume-Tracking Algorithms in a Shifting Wind Field

    Publication Year: 2008 , Page(s): 196 - 201
    Cited by:  Papers (3)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (311 KB) |  | HTML iconHTML  

    Tracking a plume of chemical back to its source is made difficult due to the complexity of plume structure caused by turbulence and shifts in the prevailing wind direction. Insects overcome this problem using forms of anemotaxis, which involve traveling upwind when an attractive chemical is perceived. In this study, two series of insect-inspired plume-tracking algorithms were implemented on a mobile robot and their performance compared under changing wind conditions in a wind tunnel. The robot was capable of sensing wind velocity and the level of a plume of ions. Ion sensors respond and recover far more rapidly than do conventional chemical sensors, so the substitution of an ion plume for a chemical plume allowed the algorithms to be implemented with rapid responses to changing plume concentration. The addition of a specific behavioral response to a wind shift decreased the time taken for the robot to find the plume source in the event of a wind shift. Increased speed came with only a minor drop in the success rate of the searching. Anemotaxis is an effective approach to chemical plume tracking with robots. The performance of these simple algorithms can be improved by modest increases in the complexity of the algorithms. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Turning Control of a Multilink Biomimetic Robotic Fish

    Publication Year: 2008 , Page(s): 201 - 206
    Cited by:  Papers (11)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (989 KB) |  | HTML iconHTML  

    This paper deals with maneuver issues of a multilink biomimetic robotic fish, particularly focusing on turning control in free swimming. The characteristic parameters determining turning performance involve magnitude, position, and time of the deflections applied to the links, which are discussed via a series of simulation calculations and actual experiments. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • A Wireless Robotic Endoscope for Gastrointestine

    Publication Year: 2008 , Page(s): 206 - 210
    Cited by:  Papers (32)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (490 KB) |  | HTML iconHTML  

    In recent years, an intelligent noninvasive endoscope has been felt necessary for early diagnosis of malignant tumor in gastrointestine (GI). It is our purpose to develop a microwireless robotic endoscope to examine the human GI. The presented robot's diameter and length is 10 and 190 mm, respectively. A locomotion principle based on biomimetic earthworm is adopted for a higher adaptability to the GI. The robot is composed of three linear driving cells. A micromotor, a reducer, and a microscrew pair mechanism are integrated into each cell. Multijoints are used to connect every two driving cells for robot's high flexibility. The robot's energy is continuously supplied in real time by an energy transmitting system based on electromagnetic coupling. Experiments on the energy transmission and locomotion are performed to test the power transferring volume and locomotion effect in GI. The experiments indicate that the minimum received power, 400 mW, is obtained in a cylindrical space with 200 mm diameter and 200 mm length. In vitro experiments in a pig intestine indicate that this robot can move forward or backward effectively. This paper provides a good prototype for the deeper research on locomotion theory and energy transferring technology in vivo in future. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Proximity Queries Between Convex Objects: An Interior Point Approach for Implicit Surfaces

    Publication Year: 2008 , Page(s): 211 - 220
    Cited by:  Papers (10)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (830 KB) |  | HTML iconHTML  

    This paper presents a general method for exact distance computation between convex objects represented as intersections of implicit surfaces. Exact distance computation algorithms are particularly important for applications involving objects that make intermittent contact, such as in dynamic simulations and in haptic interactions. They can also be used in the narrow phase of hierarchical collision detection. In contrast to geometric approaches developed for polyhedral objects, we formulate the distance computation problem as a convex optimization problem. We use an interior point method to solve the optimization problem and demonstrate that, for general convex objects represented as implicit surfaces, interior point approaches are globally convergent, and fast in practice. Further, they provide polynomial-time guarantees for implicit surface objects when the implicit surfaces have self-concordant barrier functions. We use a primal-dual interior point algorithm that solves the Karush-Kuhn-Tucker (KKT) conditions obtained from the convex programming formulation. For the case of polyhedra and quadrics, we establish a theoretical time complexity of O(n1.5), where n is the number of constraints. We present implementation results for example implicit surface objects, including polyhedra, quadrics, and generalizations of quadrics such as superquadrics and hyperquadrics, as well as intersections of these surfaces. We demonstrate that in practice, the algorithm takes time linear in the number of constraints, and that distance computation rates of about 1 kHz can be achieved. We also extend the approach to proximity queries between deforming convex objects. Finally, we show that continuous collision detection for linearly translating objects can be performed by solving two related convex optimization problems. For polyhedra and quadrics, we establish that the computational complexity of this problem is also O(n1.5). View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Navigation of Multiple Kinematically Constrained Robots

    Publication Year: 2008 , Page(s): 221 - 231
    Cited by:  Papers (25)
    Multimedia
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (960 KB)  

    In this paper, we propose a methodology for implementing multirobot navigation-function-based controllers to mixed teams of holonomic and nonholonomic agents. A new nonsmooth backstepping controller is introduced for translating kinematic controllers to equivalent dynamic ones, while maintaining bounded velocity specifications. The derived backstepping controller is applied to a dynamic model of the mobile robots, yielding a globally asymptotically stable dynamic controller. The effectiveness of the methodology is verified through nontrivial computer simulations. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.

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.

Full Aims & Scope

Meet Our Editors

Editor-in-Chief
Frank Park
Seoul National University