Showing papers on "Humanoid robot published in 2001"

The 3D linear inverted pendulum mode: a simple modeling for a biped walking pattern generation

Abstract: For 3D walking control of a biped robot we analyze the dynamics of a 3D inverted pendulum in which motion is constrained to move along an arbitrarily defined plane. This analysis yields a simple linear dynamics, the 3D linear inverted pendulum mode (3D-LIPM). Geometric nature of trajectories under the 3D-LIPM and a method for walking pattern generation are discussed. A simulation result of a walking control using a 12-DOF biped robot model is also shown.

Learning inverse kinematics

Abstract: Real-time control of the end-effector of a humanoid robot in external coordinates requires computationally efficient solutions of the inverse kinematics problem. In this context, this paper investigates inverse kinematics learning for resolved motion rate control (RMRC) employing an optimization criterion to resolve kinematic redundancies. Our learning approach is based on the key observations that learning an inverse of a nonuniquely invertible function can be accomplished by augmenting the input representation to the inverse model and by using a spatially localized learning approach. We apply this strategy to inverse kinematics learning and demonstrate how a recently developed statistical learning algorithm, locally weighted projection regression, allows efficient learning of inverse kinematic mappings in an incremental fashion even when input spaces become rather high dimensional. Our results are illustrated with a 30-DOF humanoid robot.

Experiments in adjustable autonomy

Abstract: Human-robot interaction is becoming an increasingly important research area. In this paper, we present our work on designing a human-robot system with adjustable autonomy and describe not only the prototype interface but also the corresponding, robot behaviors. In our approach, we grant the human meta-level control over the level of robot autonomy, but we allow the robot a varying amount of self-direction with each level. Within this framework of adjustable autonomy, we explore how existing, robot control approaches can be adapted and extended to be compatible with adjustable autonomy.

Robovie: an interactive humanoid robot

Abstract: The authors have developed a robot called “Robovie” that has unique mechanisms designed for communication with humans. Robovie can generate human‐like behaviors by using human‐like actuators and vision and audio sensors. Software is a key element in the systems development. Two important ideas in human‐robot communication through research from the viewpoint of cognitive science have been obtained – one is importance of physical expressions using the body and the other is the effectiveness of the robot’s autonomy in the robot’s utterance recognition by humans. Based on these psychological experiments, a new architecture that generates episode chains in interactions with humans is developed. The basic structure of the architecture is a network of situated modules. Each module consists of elemental behaviors to entrain humans and a behavior for communicating with humans.

Real-time 3D walking pattern generation for a biped robot with telescopic legs

Abstract: Meltran V, a new biped robot with telescopic legs, is introduced. For 3D walking control of the robot we analyze the dynamics of a three-dimensional inverted pendulum in which motion is constrained to move along an arbitrarily defined plane. From this analysis we obtain simple linear dynamics, the three-dimensional linear inverted pendulum mode (3D-LIPM). Using a real-time control method based on 3D-LIPM, the Meltran V robot successfully demonstrated 3D dynamic walking without the use of any prepared trajectories.

OpenHRP: Open Architecture Humanoid Robotics Platform.

Abstract: This paper presents the open architecture humanoid robotics platform (OpenHRP) which consists of a simulator and motion control library of humanoid robots. The binary software developed on OpenHRP can be applied to the real counterpart as is, thank to the proposed hardware abstraction and synchronization mechanism. The compatibility between the simulation and corresponding experiment has been successfully examined. OpenHRP is expected to initiate the exploration of humanoid robotics on open architecture software and hardware.

Footstep planning among obstacles for biped robots

Abstract: We present an algorithm for planning safe navigation strategies for biped robots moving in obstacle-cluttered environments. From a discrete set of plausible statically-stable, single-step motions, a forward dynamic programming approach is used to compute a sequence of feasible footstep locations. In contrast to existing navigation strategies for mobile robots, our method is a global method that takes into account the unique ability of legged robots such as bipedal humanoids to traverse obstacles by stepping over them. Heuristics designed to minimize the number and complexity of the step motions are used to encode cost functions used for searching a footstep transition graph. We show preliminary results of an experimental implementation of the algorithm using a model of the H6 humanoid navigating on an office floor littered with obstacles.

A new ultralight anthropomorphic hand

Abstract: In this paper a very lightweight artificial hand is presented that approximates the manipulation abilities of a human hand very well. A large variety of different objects can be grasped reliably and the movements of the hand appear to be very natural. This five finger hand has 13 independent degrees of freedom driven by a new type of powerful small size flexible fluidic actuator. The actuators are completely integrated in the fingers which made possible the design of a very compact and lightweight hand that can either be used as a prosthetic hand or as a humanoid robot hand. A mathematical model for the expansion of a flexible fluidic actuator is given and the mechanical construction and features of the new anthropomorphic hand are illustrated.

Trajectory formation for imitation with nonlinear dynamical systems

Abstract: Explores an approach to learning by imitation and trajectory formation by representing movements as mixtures of nonlinear differential equations with well-defined attractor dynamics. An observed movement is approximated by finding a best fit of the mixture model to its data by a recursive least squares regression technique. In contrast to non-autonomous movement representations like splines, the resultant movement plan remains an autonomous set of nonlinear differential equations that forms a control policy which is robust to strong external perturbations and that can be modified by additional perceptual variables. This movement policy remains the same for a given target, regardless of the initial conditions, and can easily be re-used for new targets. We evaluate the trajectory formation system in the context of a humanoid robot simulation that is part of the Virtual Trainer project, which aims at supervising rehabilitation exercises in stroke-patients. A typical rehabilitation exercise was collected with a Sarcos Sensuit, a device to record joint angular movement from human subjects, and approximated and reproduced with our imitation techniques. Our results demonstrate that multijoint human movements can be encoded successfully, and that this system allows robust modifications of the,movement policy through external variables.

Active vision for sociable robots

Abstract: Ballard (1991) described the implications of having a visual system that could actively position the camera coordinates in response to physical stimuli. In humanoid robotic systems, or in any animate vision system that interacts with people, social dynamics provide additional levels of constraint and additional opportunities for processing economy. In this paper, we describe an integrated visual-motor system that was implemented on a humanoid robot to negotiate the robot's physical constraints, the perceptual needs of the robot's behavioral and motivational systems, and the social implications of the motor acts.

A Robot that Learns to Communicate with Human Caregivers

Abstract: We are developing an infant-like humanoid robot, Infanoid , to investigate the underlying mechanisms of social intelligence that will allow it to communicate with human beings and participate in human social activities. We propose an epigenetic model of social intelligence — how the robot acquires communicative behavior through interaction with its social environment, especially with human caregivers. The model has three stages: (1) the acquisition of intentionality, which enables the robot to intentionally use certain methods for obtaining goals, (2) identification with others, which enables it to indirectly experience other people’s behavior, and (3) social communication, in which the robot empathetically understands other people’s behavior by ascribing to the intention that best explains the behavior.

Motion planning for humanoid robots under obstacle and dynamic balance constraints

Abstract: We present an approach to path planning for humanoid robots that computes dynamically-stable, collision-free trajectories from full-body posture goals. Given a geometric model of the environment and a statically-stable desired posture, we search the configuration space of the robot for a collision-free path that simultaneously satisfies dynamic balance constraints. We adapt existing randomized path planning techniques by imposing balance constraints on incremental search motions in order to maintain the overall dynamic stability of the final path. A dynamics filtering function that constrains the ZMP (zero moment point) trajectory is used as a post-processing step to transform statically-stable, collision-free paths into dynamically-stable, collision-free trajectories for the entire body. Although we have focused our experiments on biped robots with a humanoid shape, the method generally applies to any robot subject to balance constraints (legged or not). The algorithm is presented along with computed examples using the humanoid robot "H6".

Foundations for a theory of mind for a humanoid robot

Abstract: Human social dynamics rely upon the ability to correctly attribute beliefs, goals, and percepts to other people. The set of abilities that allow an individual to infer these hidden mental states based on observed actions and behavior has been called a “theory of mind” (Premack & Woodruff, 1978). Existing models of theory of mind have sought to identify a developmental progression of social skills that serve as the basis for more complex cognitive abilities. These skills include detecting eye contact, identifying self-propelled stimuli, and attributing intent to moving objects. If we are to build machines that interact naturally with people, our machines must both interpret the behavior of others according to these social rules and display the social cues that will allow people to naturally interpret the machine's behavior. Drawing from the models of Baron-Cohen (1995) and Leslie (1994), a novel architecture called embodied theory of mind was developed to link high-level cognitive skills to the low-level perceptual abilities of a humanoid robot. The implemented system determines visual saliency based on inherent object attributes, high-level task constraints, and the attentional states of others. Objects of interest are tracked in real-time to produce motion trajectories which are analyzed by a set of naive physical laws designed to discriminate animate from inanimate movement. Animate objects can be the source of attentional states (detected by finding faces and head orientation) as well as intentional states (determined by motion trajectories between objects). Individual components are evaluated by comparisons to human performance on similar tasks, and the complete system is evaluated in the context of a basic social learning mechanism that allows the robot to mimic observed movements. (Copies available exclusively from MIT Libraries, Rm. 14-0551, Cambridge, MA 02139-4307. Ph. 617-253-5668; Fax 617-253-1690.)

Virtual humanoid robot platform to develop controllers of real humanoid robots without porting

Abstract: This paper presents a virtual humanoid robot platform (V-HRP for short) on which we can develop the identical controller for a virtual humanoid robot and its real counterpart. The unification of the controllers for the virtual and real robot has been realized by introducing software adapters for two robots respectively and employing ART-Linux on which real-time processing is available at the user level. Thanks to the unification, the controllers can share softwares with the dynamics simulator of V-HRP, including the parameter parser, kinematics and dynamics computations and the collision detector. This feature can make the development of the controllers more efficient and the developed controllers more reliable.

Humanoids and Personal Robots: Design and Experiments

Abstract: This paper addresses the field of humanoid and personal robotics—its objectives, motivations, and technical problems. The approach described in the paper is based on the analysis of humanoid and personal robots as an evolution from industrial to advanced and service robotics driven by the need for helpful machines, as well as a synthesis of the dream of replicating humans. The first part of the paper describes the development of anthropomorphic components for humanoid robots, with particular regard to anthropomorphic sensors for vision and touch, an eight-d.o.f. arm, a three-fingered hand with sensorized fingertips, and control schemes for grasping. Then, the authors propose a user-oriented design methodology for personal robots, and describe their experience in the design, development, and validation of a real personal robot composed of a mobile unit integrating some of the anthropomorphic components introduced previously and aimed at operating in a distributed working environment. Based on the analysis of experimental results, the authors conclude that humanoid robotics is a tremendous and attractive technical and scientific challenge for robotics research. The real utility of humanoids has still to be demonstrated, but personal assistance can be envisaged as a promising application domain. Personal robotics also poses difficult technical problems, especially related to the need for achieving adequate safety, proper human–robot interaction, useful performance, and affordable cost. When these problems are solved, personal robots will have an excellent chance for significant application opportunities, especially if integrated into future home automation systems, and if supported by the availability of humanoid robots. © 2001 John Wiley & Sons, Inc.

Balancing a humanoid robot using backdrive concerned torque control and direct angular momentum feedback

Abstract: A balance control method for a humanoid robot is presented. It consists of a contact torque controller which is designed to have a good backdrivability and a feedback control of the total angular momentum and the center of gravity of a robot. A simulation result of a balance control using a 26 DOF humanoid robot model is shown.

Overt visual attention for a humanoid robot

Abstract: The goal of our research is to investigate the interplay between oculomotor control, visual processing, and limb control in humans and primates by exploring the computational issues of these processes with a biologically inspired artificial oculomotor system on an anthropomorphic robot. In this paper, we investigate the computational mechanisms for visual attention in such a system. Stimuli in the environment excite a dynamical neural network that implements a saliency map, i.e., a winner-take-all competition between stimuli while simultaneously smoothing out noise and suppressing irrelevant inputs. In real-time, this system computes new targets for the shift of gaze, executed by the head-eye system of the robot. The redundant degrees-of-freedom of the head-eye system are resolved through a learned inverse kinematics with optimization criterion. We also address important issues how to ensure that the coordinate system of the saliency map remains correct after movement of the robot. The presented attention system is built on principled modules and generally applicable for any sensory modality.

Motion entertainment by a small humanoid robot based on OPEN-R

Abstract: In this paper we propose a novel application of a humanoid robot: Motion Entertainment, i.e., entertaining people with motion performance of a small humanoid robot. We develop a prototype humanoid robot named SDR-3X, which is about 50 cm height with 26 DOF. Performing to high tempo music with fast speed whole body motion can provide a big impact to an audience. Some key technologies such as a newly developed actuator enable the realization of SDR-3X. In addition, the use of OPEN-R is another key factor for quick development. We describe the architecture and the key technologies of SDR-3X. We also describe a demonstration of Motion Entertainment by SDR-3X.

Educational–industrial complex development of an anthropomorphic robot hand 'Gifu hand'

Abstract: (2001). Educational–industrial complex development of an anthropomorphic robot hand 'Gifu hand' Advanced Robotics: Vol. 15, No. 3, pp. 357-363.

Online mixture and connection of basic motions for humanoid walking control by footprint specification

Abstract: This paper introduces and describes a novel method which enables the online generation of humanoid walking patterns that follow desired footprint locations. Online generation is realized by the dynamically stable mixture and connection of pre-designed motions. Characteristics of zero moment point (ZMP) are utilized in order to maintain the overall dynamic stability of "mixed" motions. Experiments using an online pattern generation software system and online walking control joystick interface for the humanoid robot H6 are introduced to show the validity of the method.

How far away is "artificial man"

Abstract: The authors claim that a careful examination of robotics science and technology from its origins in the 1950s to its current status reveals that such progress, albeit very important, profitable, and with a strong impact on society, was basically the "side activities" to the ever-existing and continuous desire of mankind to build and realize humanoid robots, artificial men equipped uith proper intelligence capable of operating autonomously, thus replacing trained individuals for dexterous jobs. They consider such a humanoid robot through the realistic tasks/jobs it will most probably do. It is postulated that this humanoid robot be considered as a personal helper (a home robot or personal robot). Given the present level of technology, the question is posed: are we ready to move towards personal robotics, and what might be the first step? A possible answer to this question is given through a discussion of the human-like characteristics a personal robot must have; namely, human-like motion, human-like intelligence, and human-like communication.

Synchronized Robot Drumming by Neural Oscillator

Abstract: Sensory-motor integration is one of the key issues in robotics. In this paper, we propose an approach to rhythmic arm movement control that is synchronized with an external signal based on exploiting a simple neural oscillator network. Trajectory generation by the neural oscillator is a biologically inspired method that can allow us to generate a smooth and continuous trajectory. The parameter tuning of the oscillators is used to generate a synchronized movement with wide intervals. We adopted the method for the drumming task as an example task. By using this method, the robot can realize synchronized drumming with wide drumming intervals in real time. The paper also shows the experimental results of drumming by a humanoid robot.

Design and implementation of software research platform for humanoid robotics: H6

Abstract: The H6 humanoid robot has been developed as a platform for the research on perception-action coupling in intelligent behaviour of humanoid type robots. The H6 features: 1) a body which has enough DOFs and each joint has enough torque for full body motion; 2) a PC/AT compatible high-performance on-board computer which is controlled by RT-Linux so that from low-level to high-level control is achieved simultaneously; 3) self-contained and connected to a network via radio Ethernet; and 4) dynamic walking trajectory generation, motion planning and 3D vision functions are available. The H6 can be used as a common test-bed in experiment for various aspects of intelligent humanoid robotics.

Modeling of conversational strategy for the robot participating in the group conversation

Abstract: This paper describes a strategy for the conversation system to take part in human-to-human group conversation One big characteristic of the group conversation system is that it can choose whether to observe or to take turn in the conversation We implement the computational model combined with speech and gaze recognizers to keep the rules in turn taking, and define an interruption decision strategy based on an analysis of human needs And finally, we realized a humanfriendly group conversation system by combining multimodal information processing/expression abilities of humanoid robot ROBITA

Biomimetic oculomotor control

Abstract: Oculomotor control in a humanoid robot faces similar problems as biological oculomotor systems, that is, capturing targets accurately on a very narrow fovea, dealing with large delays in the control systems, the stabilization of gaze in the face of unknown perturbations of the body, selective attention, and the complexity of stereo vision. In this article, we suggest control circuits to realize three of the most basic oculomotor behaviors and their integration: the vestibulo-ocular reflex and optokinetic response (VOR-OKR) for gaze stabilization, smooth pursuit for tracking moving objects, and saccades for overt visual attention. Each of these behaviors and the mechanism for their integration were derived with inspiration from computational theories as well as behavioral and physiological data in neuroscience. Our implementations on humanoid demonstrate good performance of oculomotor behaviors, which proves to be a viable strategy to explore novel control mechanisms for humanoid robotics. Conversely, insights gained from our models have been able to directly influence views and provide new directions for computational neuroscience research.