scholarly journals A gravity balancing assistant arm design in 3-D for rehabilitation of stroke patients

2021 ◽  
Vol 336 ◽  
pp. 02016
Author(s):  
Jianbo Shu ◽  
Xuehua Tang ◽  
Fan Niu ◽  
Changchun Xia ◽  
Congcong Shi
Keyword(s):  
Potential Energy ◽  
Gravitational Potential ◽  
Energy Equation ◽  
Elastic Potential ◽  
Gravitational Potential Energy ◽  
Practical Application ◽  
Stroke Patients ◽  
Rigid Rods ◽  
Motion Process ◽  
Elastic Potential Energy

A gravity balancing assistant arm design in 3-D is a mechanical mechanism consisted of springs, rigid rods, joints and sliders, which can be modified to the geometry and inertia of the arm of stroke patients. This mechanism is designed without any controllers and motors, based solely on mechanical principles, to achieve a relative balance of gravitational potential energy and elastic potential energy, thereby reducing the burden on the arm of a stroke patient to facilitate rehabilitation. To achieve this function, first, the center of gravity of the patient’s arm will be positioned, and then the mounting position of the spring on the assistant arm will be determined. In this paper, the following objectives will be achieved: (i) the calculation of the gravitational potential energy and the elastic potential energy in the mechanism (ii) the simplification of the potential energy equation and the elimination of the coefficient of the items related to the angle. (iii) The comparison between 2-D and 3-D cases of the mechanism. (iv) The motion process of simulating the mechanism using MATLAB (v) Using MATLAB to create the energy plots (vi) Using SolidWorks to construct the prototype of the mechanism (vii) Describe the practical application and future extensions of this mechanism.

On the Perfect Gravity-Balance of a Spatial N-DOF Manipulator Based on the Localized Pseudo-Base

2009 ◽  
Author(s):  
Po-Yang Lin ◽  
Win-Bin Shieh ◽  
Dar-Zen Chen
Keyword(s):  
Exact Solution ◽  
Potential Energy ◽  
Gravitational Potential ◽  
Rotation Axis ◽  
Industrial Robot ◽  
Elastic Potential ◽  
Gravitational Potential Energy ◽  
Mass Center ◽  
Elastic Potential Energy ◽  
Six Dof

This paper offers an exact solution for the perfect gravity-balance of a class of spatial manipulators with no translational joints. The methodology used is based on the concept of conservation of the gravitational and elastic potential energy of the system. The overall gravitational potential energy of a serial-connected, n-link manipulator is identified to be contributed by n subsystems, where each subsystem is kinematically equivalent to one of the primary links of the manipulator, and possesses the accumulated mass of its post-connected links with a fixed mass center located on the subsystem. The gravitational potential energy of such a subsystem can be fully balanced by the elastic potential energy of the spring fitted between the link and its adjacent pseudo-base. Since the rotation axis of the pseudo-base is required to be in the direction of gravity, n serial-connected RSSR modules are constituted along the primary chain of the manipulator to provide a pseudo-base for each of the primary links. With one linear, zero-free-length spring fitted between each of the primary links of the manipulator and its associated pseudo-base, a static equilibrium of the considered mechanism in any configuration can be reached. A numerical example of the model of a six-DOF industrial robot has demonstrated the success of the proposed methodology.

Design of Perfectly Static-Balanced One-DOF Planar Linkage With Revolute Joint Only

2008 ◽  
Author(s):  
Po-Yang Lin ◽  
Win-Bin Shieh ◽  
Dar-Zen Chen
Keyword(s):  
Potential Energy ◽  
Gravitational Potential ◽  
Elastic Potential ◽  
Gravitational Potential Energy ◽  
Single Degree Of Freedom ◽  
Parallel Links ◽  
Parallel Motion ◽  
Systematic Methodology ◽  
Elastic Potential Energy ◽  
Spring Constants

A systematic methodology for the design of a statically balanced, single degree-of-freedom planar linkage is presented. This design methodology is based on the concept of conservation of potential energy, formulated by the use of complex number notations as link vectors of the linkage. By incorporating the loop closure equations, the gravitational potential energy of the system can be simplified as the function of the vectors of all ground-adjacent links. The balance of the gravitational potential energy of the system is then accomplished by the elastic potential energy of a zero free-length spring on each ground-adjacent link of the linkage. As a result, spring constants and installation configurations of the ground-attached springs are obtained. Since the variation of the gravitational potential energy of the linkage at all configurations can be fully compensated by that of the elastic potential energy of springs, this methodology provides an exact solution for the design of a general spring balancing mechanism without auxiliary parallel links. Illustrations of the methodology are successfully demonstrated by the spring balancing designs of a general Stephenson-III type six-bar linkage and a Watt-I type six-bar linkage with parallel motion.

Design of Perfectly Statically Balanced One-DOF Planar Linkages With Revolute Joints Only

2009 ◽  
Vol 131 (5) ◽  
Author(s):  
Po-Yang Lin ◽  
Win-Bin Shieh ◽  
Dar-Zen Chen
Keyword(s):  
Potential Energy ◽  
Gravitational Potential ◽  
Elastic Potential ◽  
Gravitational Potential Energy ◽  
Revolute Joints ◽  
Parallel Links ◽  
Parallel Motion ◽  
Elastic Potential Energy ◽  
Planar Linkages ◽  
Spring Constants

A systematic methodology for the design of a statically balanced, single degree-of-freedom planar linkage is presented. This design methodology is based on the concept of conservation of potential energy, formulated by the use of complex number notations as link vectors of the linkage. By incorporating the loop closure equations and the kinematic constraints, the gravitational potential energy of the system can be formulated as the function of the vectors of all ground-adjacent links. The balance of the gravitational potential energy of the system is then accomplished by the elastic potential energy of a zero free-length spring on each ground-adjacent link of the linkage. As a result, spring constants and installation configurations of the ground-attached springs are obtained. Since the variation in the gravitational potential energy of the linkage at all configurations can be fully compensated by that of the elastic potential energy of the ground-attached springs, this methodology provides an exact solution for the design of a general spring balancing mechanism without auxiliary parallel links. Illustrations of the methodology are successfully demonstrated by the spring balancing designs of a general Stephenson-III type six-bar linkage and a Watt-I type six-bar linkage with parallel motion.

A Friction-Bearing Calorimeter Experiment Yielding Joule's Constant

1996 ◽  
Vol 24 (4) ◽  
pp. 235-242 ◽  
Author(s):  
R. S. Mullisen
Keyword(s):  
Kinetic Energy ◽  
Potential Energy ◽  
Laboratory Experiment ◽  
Heat Loss ◽  
Gravitational Potential ◽  
Data Reduction ◽  
Gravitational Potential Energy ◽  
Experimental Procedure ◽  
Friction Bearing ◽  
Elastic Potential Energy

A simple, friction-bearing calorimeter that yields Joule's constant is described in this paper. The apparatus is easily constructed at minimal expense and may be used as a laboratory experiment. Although the design is very simple, the experimental procedure and data reduction analysis account for gravitational potential energy, elastic potential energy, translational and rotational kinetic energy, and heat loss. The result is a Joule's constant value accurate within 3%.

Tracker-assisted modelling: simultaneous validation of the conservation law of energy and the work-energy theorem

2021 ◽  
Vol 57 (1) ◽  
pp. 015012
Author(s):  
Unofre B Pili ◽  
Renante R Violanda
Keyword(s):  
Kinetic Energy ◽  
Potential Energy ◽  
Gravitational Potential ◽  
Conservation Law ◽  
Gravitational Potential Energy ◽  
Time Data ◽  
Home Based ◽  
Basic Physics ◽  
Free Falling ◽  
Work Done

Abstract The video of a free-falling object was analysed in Tracker in order to extract the position and time data. On the basis of these data, the velocity, gravitational potential energy, kinetic energy, and the work done by gravity were obtained. These led to a rather simultaneous validation of the conservation law of energy and the work–energy theorem. The superimposed plots of the kinetic energy, gravitational potential energy, and the total energy as respective functions of time and position demonstrate energy conservation quite well. The same results were observed from the plots of the potential energy against the kinetic energy. On the other hand, the work–energy theorem has emerged from the plot of the total work-done against the change in kinetic energy. Because of the accessibility of the setup, the current work is seen as suitable for a home-based activity, during these times of the pandemic in particular in which online learning has remained to be the format in some countries. With the guidance of a teacher, online or face-to-face, students in their junior or senior high school—as well as for those who are enrolled in basic physics in college—will be able to benefit from this work.

scholarly journals Walking in simulated reduced gravity: mechanical energy fluctuations and exchange

1999 ◽  
Vol 86 (1) ◽  
pp. 383-390 ◽  
Author(s):  
Timothy M. Griffin ◽  
Neil A. Tolani ◽  
Rodger Kram
Keyword(s):  
Kinetic Energy ◽  
Potential Energy ◽  
Gravitational Potential ◽  
Inverted Pendulum ◽  
Mechanical Energy ◽  
Center Of Mass ◽  
Metabolic Cost ◽  
Metabolic Energy ◽  
Gravitational Potential Energy ◽  
Reduced Gravity

Walking humans conserve mechanical and, presumably, metabolic energy with an inverted pendulum-like exchange of gravitational potential energy and horizontal kinetic energy. Walking in simulated reduced gravity involves a relatively high metabolic cost, suggesting that the inverted-pendulum mechanism is disrupted because of a mismatch of potential and kinetic energy. We tested this hypothesis by measuring the fluctuations and exchange of mechanical energy of the center of mass at different combinations of velocity and simulated reduced gravity. Subjects walked with smaller fluctuations in horizontal velocity in lower gravity, such that the ratio of horizontal kinetic to gravitational potential energy fluctuations remained constant over a fourfold change in gravity. The amount of exchange, or percent recovery, at 1.00 m/s was not significantly different at 1.00, 0.75, and 0.50 G (average 64.4%), although it decreased to 48% at 0.25 G. As a result, the amount of work performed on the center of mass does not explain the relatively high metabolic cost of walking in simulated reduced gravity.

scholarly journals A design of stretcher with auxiliary functions of lateral positioning and transferring for immobilized patients

2021 ◽  
Vol 336 ◽  
pp. 02014
Author(s):  
Ying Xiong ◽  
Xuehua Tang ◽  
Congcong Shi ◽  
Yang Yang
Keyword(s):  
Inverse Kinematics ◽  
Forward Kinematics ◽  
Motion Simulation ◽  
Practical Application ◽  
Auxiliary Functions ◽  
Rigid Rods ◽  
Hospital Bed ◽  
Motion Process ◽  
Lateral Positioning ◽  
Position State

For now, many hospitals that require nurses to move patients by hand from stretchers to a hospital bed, so a design of stretcher with auxiliary functions of lateral positioning and transferring for immobilized patients, which is a mechanical mechanism consisted of rigid rods, joints and sliders, was designed to help the nurses to move patients between beds and reduce their workload. Driven by motors, the rigid rods can be rotated, stretched or shortened so that the entire stretcher bed board can archive to a proper posture and position. In this paper, the following objectives will be achieved: (i) Create a schematic of the mechanism and describe the principles and functions (ii) the calculation of inverse kinematics, forward kinematics, dynamics (including energy), and PD control in the mechanism (iii) The motion process of simulating the mechanism using MATLAB (iv) Using MATLAB to create the plots of angle, torque, and position state (v) Using SolidWorks to construct the prototype and to implement the motion simulation of the mechanism (vi) Describe the practical application and future Extensions of this mechanism.

scholarly journals Feedback of outflows in the Taurus Molecular Cloud

2012 ◽  
Vol 8 (S292) ◽  
pp. 47-47
Author(s):  
Huixian Li ◽  
Di Li ◽  
Rendong Nan
Keyword(s):  
Kinetic Energy ◽  
Potential Energy ◽  
Gravitational Potential ◽  
Molecular Cloud ◽  
Feedback Effect ◽  
Total Kinetic Energy ◽  
Gravitational Potential Energy ◽  
Taurus Molecular Cloud

AbstractWe collected 27 outflows from the literature and found 8 new ones in the FCRAO CO maps of the Taurus molecular cloud. The total kinetic energy of the 35 outflows is found to be about 3% of the gravitational potential energy from the whole cloud. The feedback effect due to the outflows is minor in Taurus.

Sign in / Sign up

Export Citation Format

Share Document