Work-Space Calculation of a Robotic Arm Using the Articulated Total Body Model

The main objective of the paper is to design a versatile Robotic Arm that has the capability to mimic the motion of a snake such that work space of the robotic arm is maximized. Design is made to achieve maximum mobility of the Robotic Arm such that it can pick up things and placed in very complex scenarios. The design is able to give degrees of freedom to the robot so that it becomes more versatile. It has a kinematic redundancy, like that of a human arm that enables us to place objects in various orientations. This Robotic arm is equipped with a three fingered gripper that provides for efficient grasping. The paper also provides design details of three fingered gripper that is suitable to hold cylindrical objects such as bolts, cable connectors etc. Autodesk Fusion 360 has been used to make cad model of arm and grippers. The 3D arm and gripper are assembled with revolute joints. The robot is tested for its mobility by performing Kinematic Analysis.

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An Underactuated Robotic Arm Based on Differential Gears for Capturing Moving Targets: Analysis and Design

Journal of Mechanisms and Robotics ◽

10.1115/1.4032811 ◽

2016 ◽

Vol 8 (4) ◽

Cited By ~ 8

Author(s):

Qingchuan Wang ◽

Qiquan Quan ◽

Zongquan Deng ◽

Xuyan Hou

Keyword(s):

Planetary Gear ◽

Peak Torque ◽

Robotic Arm ◽

Moving Targets ◽

Structural Configuration ◽

Analysis And Design ◽

Work Space ◽

Grasp Stability ◽

Driving Torque ◽

Distal Joint

This paper presents the design of an underactuated robotic arm for capturing moving targets with an impact-absorbing capability. The arm consists of three joints (a base joint (BJ), a medial joint (MJ), and a distal joint (DJ)) that are driven by two actuators. A one-input dual-output planetary gear (PG) system, in which neither the ring gear nor the planetary carrier is fixed, is employed to distribute the driving torque between the MJ and DJ. As is well known, an underactuated arm may exhibit unstable grasping performance such that the arm loses contact with the target in certain grasping postures. Therefore, a method is presented for analyzing the equilibrium contact force and the relative movement trend between the target and the arm to determine the work space in which stable grasping is possible. The structural configuration parameters, such as the length ratios among the three beams and the reduction ratio of the PG system, were optimized to maximize the grasp stability work space. Subsequently, a prototype was designed and fabricated based on these optimized parameters. Experiments indicate that this arm design can effectively reduce the peak torque on the joints when grasping a moving target.

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Fine Structural Changes in the Microvasculature of the Mouse Pinna: Aging and Radiation Injury

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100050287 ◽

1974 ◽

Vol 32 ◽

pp. 54-55

Author(s):

S. Phyllis Steamer ◽

Rosemarie L. Devine

Keyword(s):

Structural Changes ◽

Radiation Treatment ◽

Arterial Stenosis ◽

Ultrastructural Changes ◽

Vascular Effects ◽

Microvascular Changes ◽

Surrounding Connective Tissue ◽

Fission Neutrons ◽

Total Body

The importance of radiation damage to the skin and its vasculature was recognized by the early radiologists. In more recent studies, vascular effects were shown to involve the endothelium as well as the surrounding connective tissue. Microvascular changes in the mouse pinna were studied in vivo and recorded photographically over a period of 12-18 months. Radiation treatment at 110 days of age was total body exposure to either 240 rad fission neutrons or 855 rad 60Co gamma rays. After in vivo observations in control and irradiated mice, animals were sacrificed for examination of changes in vascular fine structure. Vessels were selected from regions of specific interest that had been identified on photomicrographs. Prominent ultrastructural changes can be attributed to aging as well as to radiation treatment. Of principal concern were determinations of ultrastructural changes associated with venous dilatations, segmental arterial stenosis and tortuosities of both veins and arteries, effects that had been identified on the basis of light microscopic observations. Tortuosities and irregularly dilated vein segments were related to both aging and radiation changes but arterial stenosis was observed only in irradiated animals.

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The Fine Structure of Irradiated Mouse Heart

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100090907 ◽

1976 ◽

Vol 34 ◽

pp. 184-185

Author(s):

Vivian V. Yang ◽

S. Phyllis Stearner

Keyword(s):

Microscopic Level ◽

Ultrastructural Changes ◽

Mouse Heart ◽

Blood Vessel Wall ◽

Histopathological Changes ◽

Light Microscopic Level ◽

Γ Rays ◽

Fission Neutrons ◽

Total Body

The heart is generally considered a radioresistant organ, and has received relatively little study after total-body irradiation with doses below the acutely lethal range. Some late damage in the irradiated heart has been described at the light microscopic level. However, since the dimensions of many important structures of the blood vessel wall are submicroscopic, investigators have turned to the electron microscope for adequate visualization of histopathological changes. Our studies are designed to evaluate ultrastructural changes in the mouse heart, particularly in the capillaries and muscle fibers, for 18 months after total-body exposure, and to compare the effects of 240 rad fission neutrons and 788 rad 60Co γ-rays.Three animals from each irradiated group and three control mice were sacrificed by ether inhalation at 4 days, and at 1, 3, 6, 12, and 18 months after irradiation. The thorax was opened and the heart was fixed briefly in situwith Karnofsky's fixative.

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