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Intelligent Robots and Systems 95. 'Human Robot Interaction and Cooperative Robots', Proceedings. 1995 IEEE/RSJ International Conference on

Date 5-9 Aug. 1995

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  • Author index

    Publication Year: 1995
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    Freely Available from IEEE
  • Proceedings 1995 IEEE/RSJ International Conference on Intelligent Robots and Systems

    Publication Year: 1995
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    Freely Available from IEEE
  • Performance comparison of various control strategies for a mobile manipulator

    Publication Year: 1995 , Page(s): 473 - 479 vol.3
    Cited by:  Papers (1)
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    This paper concerns the performance comparison of different control structures based on various sensors for an agricultural mobile manipulator. The robot's mobile platform is continuously advancing, pulled by a tractor while the manipulator executes local tasks. Therefore, an existing prototype has been entirely modelled which allowed us to test each control structure using a dynamic simulator. The simulation results permit to identify the best control structure for the given constraints View full abstract»

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  • Group behaviors for systems with significant dynamics

    Publication Year: 1995 , Page(s): 528 - 534 vol.3
    Cited by:  Papers (4)  |  Patents (3)
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    Birds, fish, and many other animals travel as a flock, school, or herd. Animals in these groups must remain in close proximity while avoiding collisions with neighbors and with obstacles. We would like to reproduce this behavior for groups of artificial creatures with significant dynamics. In this paper we describe an algorithm for creatures that move as a group and evaluate the performance of the algorithm with three simulated systems: legged robots, human-like bicycle riders, and point-mass systems. Both the legged robots and the bicyclists are dynamic simulations that must control balance, facing direction, and forward speed as well as movement with the group. The point-mass systems have minimal dynamics and are included to facilitate our understanding of the effects of the dynamics on the performance of the algorithms View full abstract»

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  • Real time 3-D scene analysis by fast features detection

    Publication Year: 1995 , Page(s): 380 - 385 vol.3
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    Although intensity images can be obtained quickly, it is difficult to derive 3-D information. On the other hand, it is expensive or time consuming to get 3-D range data. In this paper, the range data obtained by a 2-D laser range finder is used to complement the intensity images for 3-D scene reconstruction. A sensor fusion method is described for fast computation of the 3-D scene. A polyhedral 3-D static model (PSM) for scene analysis is presented. The recovered features can match with the PSM to determine the location of the robot and reconstruct the scene View full abstract»

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  • Construction mechanism of group behavior with cooperation

    Publication Year: 1995 , Page(s): 535 - 542 vol.3
    Cited by:  Papers (7)
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    This paper describes a construction mechanism of group behavior on decentralized autonomous robotic systems with cooperation. The decentralized autonomous robotic systems refer to multiple robotic systems including many autonomous robots, such as the cellular robotic system (CEBOT). The CEBOT consists of a number of functional robotic units called “cells”. In the research on the CEBOT, same as the decentralized robotic systems, it is one of the most important issues to cooperate among many robots for the group behavior and to coordinate the group behavior, since it is important to organize the behavior of each robot in the multiple robotic systems. In order to organize the behavior in dynamic environment, we proposed a concept of the “self-recognition” for the decision making of the behavior in a robotic group. In addition to the proposed concept, this paper shows the construction mechanism of group behavior using the character of attractor. Based on this idea, we present the behavioral evolution of the group robotic systems View full abstract»

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  • A control strategy for stable passive running

    Publication Year: 1995 , Page(s): 152 - 157 vol.3
    Cited by:  Papers (4)
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    We present a control strategy for a simplified model of a one legged running robot which features compliant elements in series with hip and leg actuators. Proper spring selection and initial conditions result in “passive dynamic” operation close to the desired motion, without any actuation. However, this motion is not stable. The proposed controller is based on online calculations of the desired passive dynamic motion and stabilises any fixed robot speed. It also tracks large changes in desired robot velocity and remains largely passive for a wide range of velocities, despite a fixed set of springs, masses and inertias. To this end the desired motion is expressed as a function of a normalized “locomotion time” parameter. Comparisons of simulated runs with direct hip actuation show dramatic energy savings of 95% at 3m/s. Such energy savings are critical for the power autonomy of electrically actuated legged robots View full abstract»

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  • Omnidirectional holonomic mobile robot using nonholonomic wheels

    Publication Year: 1995 , Page(s): 446 - 453 vol.3
    Cited by:  Papers (3)  |  Patents (1)
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    An omnidirectional holonomic mobile robot assembled with nonholonomic wheels has been proposed. The driving wheel axis of the nonholonomic wheel has an offset distance from the steering axis of the wheel. A wheel of this style is representative of the nonholonomic system and is conventionally used for a caster wheel. In the case of the proposed mobile robot, a wheel of this style is used as a driven wheel by actuating a wheel axle and a steering axle independently. First, we describe the modeling and control of the single nonholonomic wheel, and then describe the holonomic vehicle which has a couple of these nonholonomic wheels. To avoid the nonholonomic characteristics of the wheel, we have introduced a control method which restricts the controlled statement to only the translational velocity of the supporting point of the wheel. Computer simulations of the single wheel and of the two wheeled vehicle, and experimental results of the single wheel have shown good performances View full abstract»

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  • Approximate dynamic decoupling of multilimbed robotic systems

    Publication Year: 1995 , Page(s): 480 - 485 vol.3
    Cited by:  Papers (1)
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    Dynamic analysis and control of robotic systems with more than a few degrees of freedom, taking into account the full dynamics of the system, is a difficult task. Thus, quite often assumptions are made to simplify the dynamics of the system. In this paper we investigate the validity of certain assumptions that result in approximate dynamic decoupling of parts of a closed chain system. Specifically, we consider robots with a star topology structure and investigate the dynamic interaction of the branches of such a robot when one or more branches are in contact or collision with the environment (thereby forming closed chains), comparing the exact and approximate dynamic models. Examples of star topology systems, where approximate dynamic decoupling can be applied, include multilegged (or bipedal) walking robots and multifingered hands View full abstract»

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  • Planning conditional shortest paths through an unknown environment: a framed-quadtree approach

    Publication Year: 1995 , Page(s): 33 - 38 vol.3
    Cited by:  Papers (8)
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    A conditional shortest path is a collision-free path of shortest distance based on known information on an obstacle-scattered environment at a given time. This paper investigates the problem of finding a conditional L2 shortest path through an unknown environment in which path planning is implemented “on the fly” as new obstacle information becomes available through external sensors. We propose a novel cell decomposition approach which calculates an L2 distance transform through the use of a circular path-planning wave. The proposed method is based on a new data structure, called the framed-quadtree, which combines together the accuracy of grid-based path planning techniques with the efficiency of quadtree-based techniques, hence having the advantages of both. The heart of this method is a linear time algorithm for computing dynamic Voronoi diagrams View full abstract»

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  • Parts manipulation on an intelligent motion surface

    Publication Year: 1995 , Page(s): 399 - 404 vol.3
    Cited by:  Papers (15)
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    This paper introduces the concept of using a dense array of individual manipulator mechanisms as a programmable intelligent motion surface (IMS). The individual robots in the array can be implemented in a variety of technologies with different sizes. Programmability is the common necessary characteristic for an IMS; the array, with groups of contiguous robots acting in unison, can be programmed to various configurations to have the effect of imparting force fields on objects being carried on its surface. The appropriate choice of force fields is shown to cause parts placed on the array to be moved in manners that are useful. These include such functions as translation, rotation, orientation alignment, spatial filtering and the feeding of parts. The use of the IMS is described for primitive assembly operations. Limitations of the approach, extensions and possibilities for future work, particularly in microelectromechanical system (MEMS) implementations, are discussed in detail in the paper. The practicability and the programming of such an IMS-based active assembly bench was explored in a simulated environment View full abstract»

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  • Efficient edge detection from tactile data

    Publication Year: 1995 , Page(s): 386 - 391 vol.3
    Cited by:  Papers (4)
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    A real-time tactile image processing algorithm for edge contact is presented in this paper. Based on basic elasticity results, closed-form solutions for calculating contact force and local contact geometries (i.e., location and orientation of the line of contact) from the first three moments of a tactile image are derived. Computational complexity of the proposed algorithm and those of the previous approaches are compared, and passive tactile sensing experiments are performed. It is shown that the proposed algorithm has the advantage of persevering force information and is more consistent and computationally efficient View full abstract»

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  • Transferring and regrasping a large object by cooperation of multiple mobile robots

    Publication Year: 1995 , Page(s): 543 - 548 vol.3
    Cited by:  Papers (16)
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    This paper deals with a motion planning of mobile robots during transferring a large object cooperatively by a group of multiple mobile robots (a robot group). This problem has the following characteristics: 1) a real time planning is essential because mobile robots move in an open and dynamic area in comparison to articulated robots; 2) both the object and the robot group need to avoid collision against obstacles; and 3) the object needs to be grasped stably by the robot group. The authors propose the following approach to solve this complicated problem: 1) regrasping strategy of the object is introduced in order avoid obstacles and to transfer the object stably; and 2) the motion planning is divided into two steps: the object and that of the robot group. The former step is accomplished by extending the virtual impedance method, which was proposed by authors. The latter step is realized by using nonlinear programming method, that optimizes a penalty index indicating the performance for obstacle avoidance and for stable grasping. Effectiveness of the proposed method is verified by a simulation of transferring a large circle-shaped object with three robots View full abstract»

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  • Reflexive responses to slipping in bipedal running robots

    Publication Year: 1995 , Page(s): 158 - 164 vol.3
    Cited by:  Papers (7)
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    Many robot applications require traversing uneven or unmodeled terrain. This paper explores strategies for one class of difficult terrain: slippery surfaces. We evaluate several reflexive responses to a slip using a dynamically simulated, three-dimensional, bipedal robot. We explore two kinds of reaction strategies. One strategy continues the step, in which the slip occurred. The other lifts the slipping foot and repositions the legs for another attempt. The most successful strategy positions the legs in a fixed triangular configuration on the step following a slip View full abstract»

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  • Timing and kinematics of quadrupedal walking pattern

    Publication Year: 1995 , Page(s): 303 - 307 vol.3
    Cited by:  Papers (2)
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    Improved walking of completely paralyzed paraplegic subjects assisted by multichannel functional electrical stimulation (FES) and crutches is proposed. In the resulting quadrupedal gait the center of body (COB) is both actively and passively transferred in the direction of progression. Active transfer of the COB is accomplished by electrical stimulation of ankle plantarflexors of the trailing leg. Passive displacement of the COB occurs during the unstable state when the paraplegic person is only supported by a single foot and the contralateral crutch. Comparison of the time parameters measured during human crawling on knees and arms with the crutch assisted walking is presented. Results of kinematic modeling of the present and the improved FES and crutch assisted walking are displayed in the form of supporting polygons with the trajectory of the COB projected to the ground View full abstract»

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  • Evaluation of assemblability based on statistical analysis of tolerance propagation

    Publication Year: 1995 , Page(s): 256 - 261 vol.3
    Cited by:  Papers (2)
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    In this paper we present a statistical approach to assemblability evaluation based on tolerance and clearance propagations. Tolerance affect assemblability of an assembly sequence, however, clearance can compensate for tolerance. Assembly planners in the past have assumed nominal dimensions for product components for generating feasible assembly sequences. These sequences, however, may not be assemblable in practice due to propagations and accumulations of tolerances. With this concept of clearance, approaches to compute statistical tolerance and clearance propagations for serial, parallel, and multi-loop chains are proposed. The proposed method can be a valuable tool for CAD/CAM since early detection of assembly problems can significantly reduce the product cost View full abstract»

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  • Wheel servo control based on feedforward compensation for an autonomous mobile robot

    Publication Year: 1995 , Page(s): 454 - 459 vol.3
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    In the paper, we propose a wheel controller with feedforward dynamic compensation. A wheel control system developed for autonomous mobile robots driven by two wheels is described. In the navigation of such mobile robots, large path error occurs mainly due to the disturbance from the floor and the uncompensated dynamics inherent to robot motion. The stable and robust motions in the tracking stage are often difficult to achieve without consideration of wheel dynamics. The feedforward controller is designed based on an approximate inverse model which can be obtained via a series expansion of the plant inverse model. In order to adapt to changes in the environments, the controller is implemented as an adaptive version by employing the online parameter estimator. To demonstrate the validity of the proposed controller, a series of path tracking experiments were conducted for a prototype mobile robot, LCAR, by combining it with a path tracking controller View full abstract»

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  • Wrist-mounted laser rangefinder

    Publication Year: 1995 , Page(s): 362 - 367 vol.3
    Cited by:  Papers (3)  |  Patents (1)
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    The authors developed a small, lightweight rangefinder system which can be mounted on the wrist of a robot. Ranging takes place using a binary-coded projection method based on the principle of triangulation. The head of the range finger comprises a multi-slit projector with an infrared semiconductor laser, a nematic-cholesteric phase-transition (NCPT) liquid crystal shutter, and a small CCD camera. A head size of 170 mm×80 mm×50 mm and a weight of 230 grams were achieved. A dedicated image processor was developed to speed up range data generation. The time required to produce a range image is about 0.5 second. The system was tested on a real scene of a mechanical part, which is used in truss assembly in space View full abstract»

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  • Behavior-based gait execution for the Dante II walking robot

    Publication Year: 1995 , Page(s): 274 - 279 vol.3
    Cited by:  Papers (12)
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    The Dante project is developing walking robots to explore inside volcanic craters. These robots face many challenges including generating a walking gait in rough, obstacle-filled terrain. For the walking robot Dante II, we implemented a gait controller to address this situation. Our approach is embodied in a network of asynchronous processes that establish a fundamental gait cycle while maintaining body posture, and reacting to bumps and slips. We describe our implementation, and its relation to similar behavioral approaches, and discuss Dante II's performance during testing and on its descent into Mount Spurr View full abstract»

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  • Dynamic whole-arm dexterous manipulation in the plane

    Publication Year: 1995 , Page(s): 405 - 410 vol.3
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    A dynamic model of a dexterous manipulation system can be used for predicting the feasibility of a manipulation plan generated under the quasistatic assumption but executed under dynamic conditions. Contact forces between the object and manipulator are calculated to determine whether contacts can be maintained for the planned motion. Compressive contact forces indicate that contacts can be maintained for the specified manipulation plan and this implies that actual dynamic manipulation succeeds. Results of the solution of dynamic equations are given for selected objects and video images of successful plans are shown View full abstract»

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  • Cooperative control of two industrial robots with force control devices

    Publication Year: 1995 , Page(s): 550 - 555 vol.3
    Cited by:  Patents (1)
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    This paper proposes a new strategy for manipulation of a rigid object by cooperation of multiple position-controlled manipulators using force control devices. The force control device consists of springs and a position-controlled micro-manipulator. Force control is achieved by controlling deflections of each spring by the micro-manipulator. A cooperative control algorithm considering the flexibility of macro/micro manipulators is proposed. After the differential equation of the error vector system is derived, a method of designing feedback gain matrices is shown for linearizing the system. To verify the efficiency of the algorithm, experiments are done on carrying an object by two industrial robots View full abstract»

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  • A low-cost, composite sensor array combining ultrasonic and infrared proximity sensors

    Publication Year: 1995 , Page(s): 120 - 126 vol.3
    Cited by:  Papers (8)
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    In this paper we describe our approach to the design of proximity sensor arrays. Each sensing element of the proximity sensor array is a composite sensor, i.e. a sensor which is composed of an in-air ultrasonic rangefinder and an infrared detector. This sensor arrangement is capable, in principle, to achieve a perception of the explored objects that is not necessarily limited to their geometrical properties (size, shape and location relative to the sensor); possibly, the perception can be extended to other relevant features. In this paper, we show that, in principle, a sort of perception of the surface reflectance (the color) is achievable. The concept of the proposed sensor array spans a wide range of potential applications in flexible industrial automation, service robotics and autonomous mobility. The system described, in particular, is intended for providing an advanced wheelchair with the navigational capabilities required for improving the driving skills of disabled users View full abstract»

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  • Geometric design of hexapod with integrated limb mechanism of leg and arm

    Publication Year: 1995 , Page(s): 291 - 296 vol.3
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    This paper introduces a new concept for the integration of locomotion and manipulation. “the integrated limb mechanism” covers the technical fields of both the control integration and the mechanism integration necessary for the practical working robot. Here, a six-bar linkage mechanism with four degrees-of-freedom is introduced as an example of integrated limb mechanism. Kinematic analysis for the geometric and mechanical design suggests that the mechanism satisfies a contradictory conditions, not only for leg with slow heavy motion in downward posture, but also for arm with fast light motion in upward posture. The work space that two or three arms can reach is analyzed and evaluated by volume numerically for dual arm work and triple arm work. According to these analysis, a prototype hexapod with integrated limb mechanism, “MELMANTIS”, was made View full abstract»

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  • Escapability of singular configuration for redundant manipulators via self-motion

    Publication Year: 1995 , Page(s): 78 - 83 vol.3
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    The goal of this paper is to study the behavior of general redundant manipulators near singular configurations, and investigate the escapability of redundant manipulators at a singularity. Escapability means that the manipulator can actually reconfigure itself from a singular posture to a nonsingular posture via self-motion. Criteria for the classifications of escapable and inescapable singularities are established. Examples are given to demonstrate the use of these criteria View full abstract»

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  • Intelligent fuzzy motion control of mobile robot for service use

    Publication Year: 1995 , Page(s): 486 - 491 vol.3
    Cited by:  Papers (5)  |  Patents (5)
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    The intelligent mobile robot for service use with manipulators are moved in unstructured environments. Strategy for planning, environment recognition using two kinds of sensors and locomotion control to realize autonomous locomotion of the mobile robot are described. Fuzzy qualitative simulation, GA and hierarchical node map have revealed their effectiveness for path planning of the mobile robots. The results of fuzzy robot control simulation, monitoring and experimental investigations are presented View full abstract»

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