By Topic

Robotics and Automation, IEEE Transactions on

Issue 2 • Date Apr 2003

Filter Results

Displaying Results 1 - 17 of 17
  • Automatic recalibration of an active structured light vision system

    Page(s): 259 - 268
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (819 KB) |  | HTML iconHTML  

    A structured light vision system using pattern projection is useful for robust reconstruction of three-dimensional objects. One of the major tasks in using such a system is the calibration of the sensing system. This paper presents a new method by which a two-degree-of-freedom structured light system can be automatically recalibrated, if and when the relative pose between the camera and the projector is changed. A distinct advantage of this method is that neither an accurately designed calibration device nor the prior knowledge of the motion of the camera or the scene is required. Several important cues for self-recalibration are explored. The sensitivity analysis shows that high accuracy in-depth value can be achieved with this calibration method. Some experimental results are presented to demonstrate the calibration technique. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Magnetometer and differential carrier phase GPS-aided INS for advanced vehicle control

    Page(s): 269 - 282
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (615 KB) |  | HTML iconHTML  

    This paper describes the design, analysis, implementation, and experimental results of a triple redundancy navigation system incorporating magnetometer, inertial, and carrier phase differential Global Positioning System (GPS) measurements. The navigation system is able to accurately estimate vehicle attitude (including yaw) as long as the vehicle velocity is not zero. The motivating application was lateral vehicle control for intelligent highway systems. The system was designed to operate reliably whether or not GPS and magnetometer measurements were available. The navigation system provides vehicle position, velocity, acceleration, pitch and roll, yaw, and angular rates at 150 Hz with accuracies (standard deviation) of 2.8 cm, 0.8 cm/s, 2.2 cm/s/s, 0.03°, 0.18°, and 0.1°/s. This navigation state vector was processed to produce a control state vector at approximately 30 Hz. This triplicate redundancy navigation system reliably demonstrated lateral vehicle control in the following situations: both GPS and magnetometer aiding the inertial navigation system (INS), GPS-aided INS, magnetometer aided-INS, and switching between GPS and magnetometer aiding of the INS at random times. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Price-based approach for activity coordination in a supply network

    Page(s): 335 - 346
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (594 KB) |  | HTML iconHTML  

    Pressed by market globalization and concomitant competition, more and more manufacturers are relying on their suppliers to provide raw materials and component parts so as to focus on their core competence. As a result, the coordination of activities across a network of suppliers becomes critical to quickly respond to dynamic market conditions. In this paper, a novel framework combining mathematical optimization and the contract net protocol is presented for make-to-order supply network coordination. Interactions among organizations are modeled by a set of interorganizational precedence constraints and the objective is to achieve the organizations' individual and shared goals of fast product delivery and low inventory. These interorganizational constraints are relaxed by using a set of interorganizational prices that represent marginal costs per unit time for the violation of such constraints. The overall problem is thus decomposed into organizational subproblems, where individual organizations schedule their activities based on their internal situations and interorganizational prices. Coordination is achieved through an iterative price-updating process carried out in a distributed and asynchronous manner. With prices dynamically updated and schedules adjusted, this approach coordinates activities to fulfill existing commitments while maintaining agility to take on new orders. Numerical testing results show that interorganizational prices converge and prices may change as new orders arrive to reflect the new pressure on deliveries. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • An integrated approach for product family and assembly system design

    Page(s): 324 - 334
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (474 KB)  

    The main objective of the research presented in this paper was to develop a new philosophy for the design of a product family (PF) and its assembly system. Most methodologies usually do not consider the interactions between these two design processes. Moreover, most "assembly-centered" concurrent engineering approaches do not deal with PFs. A research project, called CISAL, was initiated in Belgium in the late nineties to tackle this problem. The proposed tool is intended to be applicable to PFs and hybrid assembly lines (presenting manual, robotic and automated operations). It is subdivided into three interacting main modules: preliminary design for assembly (DFA) and assembly planning (AP); detailed DFA and AP; and line layout. The whole methodology is articulated around the functional entities (FEns), resulting from a first-order decomposition of the PF and aiming at reducing the complexity inherent to the design of multivariant products. All tools presented take this decomposition into account and treat design issues related to each FEn separately, considering the PF as an assembly of FEns. This paper presents the framework of CISAL, and the underlying methodology is illustrated on an industrial case study. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Cobot implementation of virtual paths and 3D virtual surfaces

    Page(s): 347 - 351
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (617 KB) |  | HTML iconHTML  

    Cobots are devices for human/robot interaction, in which axes of motion are coupled to one another by computer-controlled continuously variable transmissions rather than individually driven by servomotors. We have recently built a cobot with a three-dimensional workspace and a 3-revolute parallelogram-type mechanism. Here we present the control methods for the display of virtual surfaces and for free mode in which the cobot endpoint moves as if it were unconstrained. We provide experimental results on the performance of the free, virtual path, and virtual surface controllers. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Forward model for sonar maps produced with the Polaroid ranging module

    Page(s): 358 - 362
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (273 KB) |  | HTML iconHTML  

    Conventional Polaroid time-of-flight (TOF) sonars provide object range measurements, but their wide beam widths limit the object bearing accuracy. We describe a first-order model that predicts the TOF readings from an object at a given range, bearing, and reflecting strength produced by the Polaroid 6500 series sonar ranging module connected to a 600 series electrostatic transducer. The model provides a simple method for solving the inverse problem of estimating these object parameters from conventional TOF data. Experimental results are given to demonstrate the model performance. Our model provides a reasonable fit for main-lobe data observed for objects with reflecting strengths that vary by 25 dB. An example of an inverse problem solution demonstrates the model can improve object range and bearing measurements, and can also estimate the object reflecting strength, a landmark feature useful for robot navigation tasks. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Self-adaptive recurrent neuro-fuzzy control of an autonomous underwater vehicle

    Page(s): 283 - 295
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (857 KB) |  | HTML iconHTML  

    This paper presents the utilization of a self-adaptive recurrent neuro-fuzzy control as a feedforward controller and a proportional-plus-derivative (PD) control as a feedback controller for controlling an autonomous underwater vehicle (AUV) in an unstructured environment. Without a priori knowledge, the recurrent neuro-fuzzy system is first trained to model the inverse dynamics of the AUV and then utilized as a feedforward controller to compute the nominal torque of the AUV along a desired trajectory. The PD feedback controller computes the error torque to minimize the system error along the desired trajectory. This error torque also provides an error signal for online updating the parameters in the recurrent neuro-fuzzy control to adapt in a changing environment. A systematic self-adaptive learning algorithm, consisting of a mapping-constrained agglomerative clustering algorithm for the structure learning and a recursive recurrent learning algorithm for the parameter learning, has been developed to construct the recurrent neuro-fuzzy system to model the inverse dynamics of an AUV with fast learning convergence. Computer simulations of the proposed recurrent neuro-fuzzy control scheme and its performance comparison with some existing controllers have been conducted to validate the effectiveness of the proposed approach. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • A comparison study of two 3-DOF parallel manipulators: one with three and the other with four supporting legs

    Page(s): 200 - 209
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (1387 KB) |  | HTML iconHTML  

    This paper presents a comparison study of the well-conditioned workspace and stiffness properties of two 3-degree-of-freedom (DOF) parallel manipulators, one with three supporting limbs and the other with four supporting limbs. The inverse kinematics and Jacobian of these two mechanisms are analyzed. The well-conditioned workspace of each mechanism is maximized and the stiffness properties are determined. A comparison of the results indicates that the Tricept manipulator out performs the 3-UPU parallel manipulator. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Diagnosis of repeated/intermittent failures in discrete event systems

    Page(s): 310 - 323
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (999 KB) |  | HTML iconHTML  

    We introduce the notion of repeated failure diagnosability for diagnosing the occurrence of a repeated number of failures in discrete event systems. This generalizes the earlier notion of diagnosability that was used to diagnose the occurrence of a failure, but from which the information regarding the multiplicity of the occurrence of the failure could not be obtained. It is possible that in some systems the same type of failure repeats a multiple number of times. It is desirable to have a diagnoser which not only diagnoses that such a failure has occurred, but also determines the number of times the failure has occurred. To aid such analysis we introduce the notions of K-diagnosability (K failures diagnosability), [1, K]-diagnosability (1 through K failures diagnosability), and [1, ∞]-diagnosability (1 through ∞ failures diagnosability). Here the first (resp., last) notion is the weakest (resp., strongest) of all three and the earlier notion of diagnosability is the same as that of K-diagnosability or that of [1, K]-diagnosability with K=1. We give polynomial algorithms for checking these various notions of repeated failure diagnosability and also present a procedure of polynomial complexity for the online diagnosis of repeated failures. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Robust scene reconstruction from an omnidirectional vision system

    Page(s): 351 - 357
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (763 KB) |  | HTML iconHTML  

    In this paper, we present an efficient multi-baseline stereo algorithm for panoramic image data. We derive a parameterization of epipolar curves in terms of inverse depth. As a result, the search for image correspondences across multiple images can be performed efficiently. Furthermore, depth estimates are obtained directly, thus bypassing the need to perform explicit stereoscopic triangulation. We apply our method to obtain a three-dimensional reconstruction of an environment from a set of panoramic images. The images are acquired by a single omnidirectional vision sensor mounted on top of our mobile robot during navigation. Experimental results demonstrate the effectiveness of our approach. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • State space modeling of dimensional variation propagation in multistage machining process using differential motion vectors

    Page(s): 296 - 309
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (1111 KB)  

    In this paper, a state space model is developed to describe the dimensional variation propagation of multistage machining processes. A complicated machining system usually contains multiple stages. When the workpiece passes through multiple stages, machining errors at each stage will be accumulated and transformed onto the workpiece. Differential motion vector, a concept from the robotics field, is used in this model as the state vector to represent the geometric deviation of the workpiece. The deviation accumulation and transformation are quantitatively described by the state transition in the state space model. A systematic procedure that builds the model is presented and an experimental validation is also conducted. The validation result is satisfactory. This model has great potential to be applied to fault diagnosis and process design evaluation for complicated machining processes. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • A human-assisting manipulator teleoperated by EMG signals and arm motions

    Page(s): 210 - 222
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (1175 KB) |  | HTML iconHTML  

    This paper proposes a human-assisting manipulator teleoperated by electromyographic (EMG) signals and arm motions. The proposed method can realize a new master-slave manipulator system that uses no mechanical master controller. A person whose forearm has been amputated can use this manipulator as a personal assistant for desktop work. The control system consists of a hand and wrist control part and an arm control part. The hand and wrist control part selects an active joint in the manipulator's end-effector and controls it based on EMG pattern discrimination. The arm control part measures the position of the operator's wrist joint or the amputated part using a three-dimensional position sensor, and the joint angles of the manipulator's arm, except for the end-effector part, are controlled according to this position, which, in turn, corresponds to the position of the manipulator's joint. These control parts enable the operator to control the manipulator intuitively. The distinctive feature of our system is to use a novel statistical neural network for EMG pattern discrimination. The system can adapt itself to changes of the EMG patterns according to the differences among individuals, different locations of the electrodes, and time variation caused by fatigue or sweat. Our experiments have shown that the developed system could learn and estimate the operator's intended motions with a high degree of accuracy using the EMG signals, and that the manipulator could be controlled smoothly. We also confirmed that our system could assist the amputee in performing desktop work. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Independent finger and independent joint-based compliance control of multifingered robot hands

    Page(s): 185 - 199
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (1046 KB) |  | HTML iconHTML  

    In this paper, a modified two-step compliance control method for robot hands is proposed: resolved interfinger decoupling solver (RIFDS) and resolved interjoint decoupling solver (RIJDS). For this, we first investigate how many fingers are necessary to successfully implement stiffness characteristics in the operational space. RIFDS is then proposed to decompose the desired compliance characteristic specified in the operational space into the compliance characteristic in the fingertip space without interfinger coupling, and RIJDS is also proposed to decompose the compliance characteristic in the fingertip space without interjoint coupling. It is found in the process of RIFDS that some nondiagonal stiffness elements specified in the operational space cannot be planned arbitrarily, due to grasping geometry. Similar to independent finger control, RIJDS aims at independent joint control. This scheme facilitates the joint servo control. To show the effectiveness of the proposed compliance control method, some experimental results are illustrated for a compliant task by using two- and three-fingered hands, which consist of five-bar finger mechanisms. It is concluded that grasping geometry and finger structure are crucial to successfully performing multifingered hands operations. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Time-scaling control for an underactuated biped robot

    Page(s): 362 - 368
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (453 KB) |  | HTML iconHTML  

    This paper presents a control law for the tracking of a cyclic reference trajectory by an underactuated biped robot. The robot studied is a five-link planar robot. The degree of underactuation is one during the single support phase. The control law is defined in such a way that only the geometric evolution of the robot is controlled, not the temporal evolution. To achieve this objective, we consider a time-scaling control. For a given reference path, the temporal evolution during the geometric tracking is completely defined and can be analyzed through the study of the dynamic model. A simple analytical condition is deduced that guarantees convergence toward the cyclic reference trajectory. This condition implies temporal convergence after the geometric convergence. This condition is defined on the cyclic reference path. The control law is stable if the angular momentum around the contact point is greater at the end of the single support phase than at the beginning of the single support phase. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Path planning with uncalibrated stereo rig for image-based visual servoing under large pose discrepancy

    Page(s): 250 - 258
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (822 KB)  

    Although image-based visual servoing provides superior performance in many vision-based robotic applications, it reveals fatal limitations when initial pose discrepancy is large. The feature points may leave the camera's field of view, and also, the robot may not converge to the goal configuration. In this paper, a novel approach is proposed to resolve these limitations by planning trajectories in the image space using uncalibrated stereo cameras. Intermediate views of the robot gripper are synthesized to generate the image trajectories such that the gripper can track a straight path in the three-dimensional workspace. The proposed method utilizes screw motions of the gripper represented in the projective space with the help of the fundamental properties of projective geometry. Computational issues are also considered to enhance the estimation of the projective transformation from initial to goal configuration. The validity of this approach is demonstrated through computer simulations and limited experiments. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Simultaneous localization and map building for a team of cooperating robots: a set membership approach

    Page(s): 238 - 249
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (602 KB) |  | HTML iconHTML  

    The problem of simultaneous localization and map building for a team of cooperating robots moving in an unknown environment is addressed. The robots have to estimate the position of distinguishable static landmarks, and then localize themselves with respect to other robots and landmarks, exploiting distance and angle measurements. A novel set theoretic approach to this problem is presented. The proposed localization algorithm provides position estimates and guaranteed uncertainty regions for all robots and landmarks in the environment. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Motion planning of multiple mobile robots for Cooperative manipulation and transportation

    Page(s): 223 - 237
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (2124 KB) |  | HTML iconHTML  

    In this paper, we propose a motion-planning method of multiple mobile robots for cooperative transportation of a large object in a three-dimensional environment. This task has various kinds of problems, such as obstacle avoidance and stable manipulation. All of these problems cannot be solved at once, since it would result in a dramatic increase of the computational time. Accordingly, we divided the motion planner into a global path planner and a local manipulation planner, designed them, and integrated them. The aim was to integrate a gross motion planner and a fine motion planner. Concerning the global path planner, we reduced the dimensions of the configuration space (C-space) using the feature of transportation by mobile robots. We used the potential field to find the solution by searching in this smaller-dimension reconstructed C-space. In the global path planner, the constraints of the object manipulation are considered as the cost function and the heuristic function in the A* search. For the local manipulation planner, we developed a manipulation technique, which is suitable for mobile robots by position control. We computed the conditions in which the object becomes unstable during manipulation and generated each robot's motion, considering the robots' motion errors and indefinite factors from the planning stage. We verified the effectiveness of our proposed motion planning method through simulations. View full abstract»

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

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