Tele-existence is an advanced type of teleoperation system that enables a human operator at the controls to perform remote manipulation tasks dexterously with the feeling that he or she exists in the remote anthropomorphic robot in the... more
Tele-existence is an advanced type of teleoperation system that enables a human operator at the controls to perform remote manipulation tasks dexterously with the feeling that he or she exists in the remote anthropomorphic robot in the remote environment. The concept of a tele-existence is presented, the principle of the tele-existence display method is explained, some of the prototype systems are described, and its space application is discussed.
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Tele-existence is an advanced type of teleoperation system that enables a human operator at the controls to perform remote manipulation tasks dexterously with the feeling that he or she exists in the remote anthropomorphic robot in the... more
Tele-existence is an advanced type of teleoperation system that enables a human operator at the controls to perform remote manipulation tasks dexterously with the feeling that he or she exists in the remote anthropomorphic robot in the remote environment. In this report the concept of the tele-existence is shown, the principle of the tele-existence display method is explained, some of the prototype systems are described, and its space application is discussed.
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Disturbance compensation control of a free-flying space robot is considered in this paper. In the method proposed here, disturbances imposed on a nominal dynamic model are estimated and compensated by utilizing a combination of joint... more
Disturbance compensation control of a free-flying space robot is considered in this paper. In the method proposed here, disturbances imposed on a nominal dynamic model are estimated and compensated by utilizing a combination of joint torque input and acceleration signals. The dynamics of the equivalent manipulator with a fixed base is treated as the nominal model, noting that the mass of the base satellite is usually much larger than that of the manipulator. The attitude of the base satellite changes because of the reaction force generated by the manipulator. However, the influence of the change is estimated and compensated as a disturbance based on a combination of the joint torque and the acceleration of the end-effector in the operational coordinate frame. Computation of the proposed control method is as simple as the control of a manipulator with a fixed base. The proposed method is robust against unknown disturbances and modeling errors. This method can also be extended to the ...
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IEEE TRANSACTIONS ON ROBOTICS is published by the IEEE Robotics and Automation Society. All members of the IEEE are eligible for membership in the Society and will receive this TRANSACTIONS upon payment of the annual Society membership... more
IEEE TRANSACTIONS ON ROBOTICS is published by the IEEE Robotics and Automation Society. All members of the IEEE are eligible for membership in the Society and will receive this TRANSACTIONS upon payment of the annual Society membership fee of $25.00 plus an annual subscription fee of $19.00. For information on joining, write to the lEEE Service Center at the address below. Member copies of Transactions/Journals are for personal use only. IEEE ROBOTICS AND AUTOMATION SOCIETY URL: http://www.ncsu.edu/IEEE-RAS/ (Continued on inside ...
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In this study, an artificial neural network (ANN) model was constructed to investigate the relationship between the roller path parameters to form a cylindrical cup in multi-pass conventional spinning and the thickness distribution... more
In this study, an artificial neural network (ANN) model was constructed to investigate the relationship between the roller path parameters to form a cylindrical cup in multi-pass conventional spinning and the thickness distribution throughout the height of a workpiece. Furthermore, the path parameters that simultaneously realize multiple target values of the workpiece dimensions were calculated instantly by the iterative solution based on the constructed model. A systematic design of the path parameters for a constant thickness distribution was established as follows. First, the roller path was expressed using 12 parameters. Second, the workpieces were spun under various experimental conditions, which were determined by partial randomization of the orthogonal array based on the Taguchi method. Third, an ANN model was trained by considering seven path parameters as inputs and five forming result values as outputs (cup height, wall thickness at 25%, 50%, and 75% of the cup height, and...
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The concept of discrete-time nonholonomic systems, in which the constraints are represented as difference equations of generalized coordinates, is introduced. Such systems can be seen in the digital control of continuous-time nonholonomic... more
The concept of discrete-time nonholonomic systems, in which the constraints are represented as difference equations of generalized coordinates, is introduced. Such systems can be seen in the digital control of continuous-time nonholonomic systems, and in mechanical systems with repetitive and discontinuous constraints. A two-wheeled mobile robot and pivoting manipulation of a polyhedral object are described as simple examples. The k-step reachable region is dened as the set of the k-th state which the system can reach from the initial state, and the reachability of such systems is discussed. A motion planning method using the Jacobian matrix of the state with regard to the input series is proposed.
The invention relates to monoclonal anti-idiotypic antibodies to human anti-DNA antibodies. Monoclonal, anti-idiotypic antibodies are produced using hybridoma technology. The antibodies are used as diagnostic reagents in methods to... more
The invention relates to monoclonal anti-idiotypic antibodies to human anti-DNA antibodies. Monoclonal, anti-idiotypic antibodies are produced using hybridoma technology. The antibodies are used as diagnostic reagents in methods to determine the presence of anti-native DNA antibodies in serum from patients suspected of having systemic lupus erythematosus.
Tele-existence is a cone泡pt named for the technology which enables a human being to have a real time sensation of being at the place other than the place where he or she actually exists, and is able to interact with the remote and/or... more
Tele-existence is a cone泡pt named for the technology which enables a human being to have a real time sensation of being at the place other than the place where he or she actually exists, and is able to interact with the remote and/or virtual environment. He or she can tele-exist in a real world where the robot exists or in a virtual world which a computer has generated. It 1s possible to tele-exist in a combined environment of real and virtual. Artificial reality or virtual reality is a technology which presents a human being a sensation of being involved in a realistic vIItual environment other than the environment where he or she really exists, and can interact with the virtual environment. Thus tele-existence and artificial reality are essentially the same technology expressed in different manners. In this key note paper, the concept of tele-existence and/or artificial reality is considered from the standpoint of measurement and control, and an experimental tele-existence system ...
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This study clarified the strain state evolution of a cylindrical cup spun from a rolled aluminum sheet in 13 passes. Measurements of radial (ɛr), circumferential (ɛθ), and thickness (ɛt) directional strains as well as forming forces... more
This study clarified the strain state evolution of a cylindrical cup spun from a rolled aluminum sheet in 13 passes. Measurements of radial (ɛr), circumferential (ɛθ), and thickness (ɛt) directional strains as well as forming forces revealed that the strain state evolved as follows: the cup-wall exhibits ɛr < 0 and small |ɛθ| and |ɛt| in early passes and ɛr > 0, ɛθ < 0, and ɛt < 0 in later passes; meanwhile, the cup-edge exhibits ɛr > 0 and small |ɛθ| and |ɛt| in early passes and ɛr > 0, ɛθ < 0, and ɛt > 0 in later passes. The relationship between the strain states and the forming force is interpreted as follows. The normal direction forming force, which pushes into the workpiece in the thickness direction, primarily deforms the workpieces. The radial direction forming force, toward the edge along the workpiece configuration, facilitates elongation in the radial direction of the cup-wall and results in ɛr > 0 during spinning. By contrast, a small radial di...
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This study clarified the evolution of texture in the thickness direction of the cylindrical cup which was spun from a rolled aluminum sheet in 13 passes, using electron backscatter diffraction pattern analysis. The study also obtained the... more
This study clarified the evolution of texture in the thickness direction of the cylindrical cup which was spun from a rolled aluminum sheet in 13 passes, using electron backscatter diffraction pattern analysis. The study also obtained the relationship between the strain and layer structure, characterized by the textures. The spun workpiece had three layers in the thickness direction. The layer structure was composed of four types of textures: the Cu texture, “texture-I”, which rotated 20° around <111> from the Cu texture; “texture-II”, which rotated 5° around its <110> from the Cu texture; and “texture-III”, which rotated 10° around its <001> from texture-I. When a blank disk had the sandwich-type layer structure Cu-I-Cu in its thickness direction, the structure changed to the Cu-II-II and Cu-III-III layer structures for the negative and positive thickness directional strains, respectively. A complex-type structure was found in the transition from Cu-I-Cu to Cu-II-...
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In this paper, we propose a method of forming a tube into an oblique/curved shape by synchronous multipass spinning, in which the forming roller reciprocates in the radial direction in synchrony with the rotation angle of the spindle... more
In this paper, we propose a method of forming a tube into an oblique/curved shape by synchronous multipass spinning, in which the forming roller reciprocates in the radial direction in synchrony with the rotation angle of the spindle while the roller moves back and forth along the workpiece in the axial direction to gradually deform a blank tube into a target shape. The target oblique/curved shape is expressed as a series of inclined circular cross sections. The contact position of the roller and the workpiece is calculated from the inclination angle, center coordinates, and diameter of the cross sections, considering the geometrical shape of the roller. The blank shape and the target shape are interpolated along normalized tool paths to generate the numerical control command of the roller. By this method, we experimentally formed aluminum tubes into curved shapes with various radii of curvature, and the forming accuracy, thickness distribution, and strain distribution are examined....
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In proposing variable nonholonomic constraint for cooperative human-robot handling, we deal with nonholonomic wheel movement manipulated intuitively by the use. We propose implementing virtual nonholonomic constraint in robot grasping,... more
In proposing variable nonholonomic constraint for cooperative human-robot handling, we deal with nonholonomic wheel movement manipulated intuitively by the use. We propose implementing virtual nonholonomic constraint in robot grasping, enabling users to transfer objects, similar to using a wheelbarrow, without slipping. Transporting objects accurately in a fixed constraint point requires skill, so we propose preparing multiple constraint points to be selected based on the situation. We apply this to a mobile manipulator, confirming feasibility experimentally.
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This paper present the design concept of a power assist system. In such system, when the controller is designed without considering the maximum torque of the actuators, the actuators can sometimes become saturated, resulting in a loss of... more
This paper present the design concept of a power assist system. In such system, when the controller is designed without considering the maximum torque of the actuators, the actuators can sometimes become saturated, resulting in a loss of stability and manoeuvrability. We propose a method for dealing with this problem. The load force is divided into gravitational and dynamic component, and each component is attenuated by an individual ratio. These ratios are determined considering the maximum power of the operator and the actuators.