73 research outputs found

    Robotic tele-existence

    Get PDF
    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

    Effect of Pass-set Shape on Formability in Synchronous Multipass Spinning

    Get PDF
    AbstractSynchronous multi pass spinning is a metal spinning method that can form asymmetric shapes with a noncircular bottom and vertical walls from a metal sheet. In this method, the tool trajectory is calculated by linear interpolation between the mandrel shape and the blank disk shape along a pass set. Here, the pass set corresponds to the tool trajectory in conventional spinning. The aim of this study is to examine the effect of a pass set on the formability of a circular cup shape and a rectangular box shape. We have experimentally examined the formability using various pass sets made by simple rule. The angle growth of the rotational pass set, the incremental movement of the translational pass set, and the nominal product height are varied for comparison in the experiments

    Organoids with cancer stem cell-like properties secrete exosomes and HSP90 in a 3D nanoenvironment

    Get PDF
    Ability to form cellular aggregations such as tumorspheres and spheroids have been used as a morphological marker of malignant cancer cells and in particular cancer stem cells (CSC). However, the common definition of the types of cellular aggregation formed by cancer cells has not been available. We examined morphologies of 67 cell lines cultured on three dimensional morphology enhancing NanoCulture Plates (NCP) and classified the types of cellular aggregates that form. Among the 67 cell lines, 49 cell lines formed spheres or spheroids, 8 cell lines formed grape-like aggregation (GLA), 8 cell lines formed other types of aggregation, and 3 cell lines formed monolayer sheets. Seven GLA-forming cell lines were derived from adenocarcinoma among the 8 lines. A neuroendocrine adenocarcinoma cell line PC-3 formed asymmetric GLA with ductal structures on the NCPs and rapidly growing asymmetric tumors that metastasized to lymph nodes in immunocompromised mice. In contrast, another adenocarcinoma cell line DU-145 formed spheroids in vitro and spheroid-like tumors in vivo that did not metastasize to lymph nodes until day 50 after transplantation. Culture in the 3D nanoenvironment and in a defined stem cell medium enabled the neuroendocrine adenocarcinoma cells to form slowly growing large organoids that expressed multiple stem cell markers, neuroendocrine markers, intercellular adhesion molecules, and oncogenes in vitro. In contrast, the more commonly used 2D serum-contained environment reduced intercellular adhesion and induced mesenchymal transition and promoted rapid growth of the cells. In addition, the 3D stemness nanoenvironment promoted secretion of HSP90 and EpCAM-exosomes, a marker of CSC phenotype, from the neuroendocrine organoids. These findings indicate that the NCP-based 3D environment enables cells to form stem cell tumoroids with multipotency and model more accurately the in vivo tumor status at the levels of morphology and gene expression

    運動習慣を持つ高齢者の生活習慣と運動の実施状況

    Get PDF
    We used a questionnaire to survey elderly subjects (65-74 years old) who worked out physically 30 or more minutes per day two or more times per week over a period of one year or longer. We obtained the following results: 1. We were able to categorize the active elderly into two types: a) those who concerned themselves with one particular sport, and b) those who concerned themselves with two or more kinds of sports. 2. Comparison of subjects\u27 answers with the average scores for Japan (from a survey conducted by the Ministry of Health, Labor and Welfare) showed that the subjects of this study had higher levels of self-confidence in health and fitness, had more regular eating habits, and were less likely to be smokers. The subjects can be said to be highly concerned with their own health

    Oblique/Curved Tube Necking Formed by Synchronous Multipass Spinning

    No full text
    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. We verified that the curved shapes with the target radii of curvature can be accurately realized

    Position control system of a two degree of freedom manipulator with a passive joint

    No full text
    The authors propose a method of controlling the position of a manipulator with passive joints that have holding brakes instead of actuators. In this method, the coupling characteristics of manipulator dynamics are used, and no additional mechanisms are required. In this paper, the effectiveness of the method is verified by experiments using a prototype manipulator. The prototype is a two-degree-of-freedom (dof), horizontally articulated manipulator. The first axis is an active joint, and the second axis is a passive joint. While the brake of the passive joint is released, the passive joint is indirectly controlled by the motion of the active joint through the use of dynamic coupling. While the brake is engaged, the active joint is controlled. By combining these two control modes, total position of the manipulator is controlled. The experiments show that the precise positioning of the passive joint is feasible by use of the proposed method

    Position Control of a Manipulator with Passive Joints Using Dynamic Coupling

    Get PDF
    This paper describes a method ofcontrolling the position of a manipulator composed of active and passive joints. The active joints have actuators and position sensors. The passive joints have holding brakes instead of actuators. While the brakes are released, the passive joints are indirectly controlled by the motion of the active joints using the coupling characteristics of manipulator dynamics. While the brakes are engaged, the passive joints are fixed and the activejoints are controlled. The position of the manipulator is controlled by combining these two control modes. This paper describes the basic principle of the control method and the conditions that ensure the controllability of the passive joints. An algorithm for point-to-point control of the manipulator is also presented. The feasibility of the method is demonstrated by simulations for a manipulator with two degrees of freedom

    Study on a Wheeled Caster for Design of Low-Crash Wagons

    No full text

    Downloaded from

    No full text
    Motion planning for coupled rigid bodies in a horizontal plane is investigated. The rigid bodies are serially connected by passive revolute joints. The dynamic constraints on the system are second-order nonholonomic constraints. We attempted to control those n coupled rigid bodies by the translational acceleration inputs at the first joint. If each rigid body is hinged at the center of percussion, it is possible to compose a positioning trajectory by connecting rotational and translational trajectory segments. Each rigid body can be rotated about its center of percussion one after another. When all of the rigid bodies are aligned on a straight line, they can be translated. The algorithm for positioning is presented. Simulations show that the coupled planar rigid bodies can reach the desired configuration by the constructed inputs. KEY WORDS—coupled rigid bodies, passive revolute joints, nonholonomic motion planning, positioning, second-order nonholonomic constraints, underactuated system 1

    Position control system of a two degree of freedom manipulator with a passive joint

    No full text
    corecore