scholarly journals Kinematic Synthesis of 3R-1P Geared Slider Crank Mechanism with Variable Topology Features for Motion Generation

2021 ◽  
pp. 317-322
Author(s):  
H. M. Naveen ◽  
Shrinivas S. Balli ◽  
Umesh M. Daivagna
Keyword(s):  
Complex Number ◽  
Degree Of Freedom ◽  
Motion Generation ◽  
Modes Of Operation ◽  
Kinematic Synthesis ◽  
Input And Output ◽  
Variable Topology ◽  
Crank Mechanism

The paper focuses on synthesis of slider crank mechanism consisting of a single gear as a part of input and output of the mechanism. Complex number method is used as one of the synthesis criteria. This is a planar four link gear slider mechanism having one degree of freedom which is considered for synthesis using variable topology method for the task of motion generation. The mechanism consists of three revolute and one slider joints. Synthesized mechanism exhibits the features of variable topology mechanism in different modes of operation.

scholarly journals Development and evaluation of a handheld type 6 DoF midair haptic device using asymmetric vibration and a presentation force vectoring mechanism

2021 ◽  
Author(s):  
Yuto Okuda ◽  
Shunsuke Komizunai ◽  
Atsushi Konno
Keyword(s):  
Inverse Problem ◽  
Problem Solving ◽  
Degree Of Freedom ◽  
Haptic Device ◽  
Input And Output ◽  
User Test ◽  
Original Presentation ◽  
Force Sense ◽  
Asymmetric Vibration

Abstract This paper describes a handheld type aerial haptic device with 6 DoF (degree of freedom) using pseudo-haptics by asymmetric vibration. By introducing a original presentation force vectoring mechanism, 6 DoF force sense presentation and compactness suitable for handheld use with a small number of vibrators are realized together. In addition, a relationship between the drive input and output (presentation force sense) of the developed device is formulated, and its inverse problem solving method for obtaining the drive input that realizes a desired presentation force sense is derived. Furthermore, a user test clarified the direction in which this device can / cannot effectively exert force.

scholarly journals Design of a Spatial RPR-2SS Valve Mechanism

2018 ◽  
Vol 10 (4) ◽  
Author(s):  
Peter L. Wang ◽  
Ulrich Rhem ◽  
J. Michael McCarthy
Keyword(s):  
Tunnel Boring Machine ◽  
Degree Of Freedom ◽  
Valve Mechanism ◽  
Kinematic Synthesis ◽  
Soil Conditioning ◽  
Spatial Mechanism ◽  
Tunnel Boring ◽  
Serial Chain ◽  
Smooth Movement ◽  
Cylindrical Array

This paper applies kinematic synthesis theory to obtain the dimensions of a constrained spatial serial chain for a valve mechanism that cleans and closes a soil conditioning port in a tunnel boring machine. The goal is a smooth movement that rotates a cylindrical array of studs into position and then translates it forward to clean and close the port. The movement of the valve is defined by six positions of the revolute-prismatic-revolute (RPR) serial chain. These six positions are used to compute the dimensions of the two spherical spherical (SS) dyads that constrain the RPR chain to obtain a one degree-of-freedom spatial mechanism. An example design of this valve mechanism is provided in detail.

Design and Actuation of a Skeleton for a Robotic Fish

2021 ◽  
Author(s):  
Dina Joy K. Abulon ◽  
Jiaji Li ◽  
J. Michael McCarthy
Keyword(s):  
Degree Of Freedom ◽  
Robotic Fish ◽  
Air Pressure ◽  
Kinematic Synthesis ◽  
Locomotion System ◽  
Synthesis Procedure

Abstract In this paper, we present the design of a pneumatically actuated skeleton for a robotic fish. The tail is designed as a one degree of freedom coiling truss that is actuated by air pressure supplied to pouch actuators along the truss. We present that kinematic synthesis procedure, the fabrication and testing of the fish tail system. Our goal is an efficient and effective fish-like locomotion system.

Conditions for Self-Locking in Planetary Gear Trains

2006 ◽  
Vol 129 (9) ◽  
pp. 960-968 ◽  
Author(s):  
David R. Salgado ◽  
J. M. del Castillo
Keyword(s):  
Planetary Gear ◽  
Degree Of Freedom ◽  
The Self ◽  
Gear Train ◽  
Planetary Gear Train ◽  
Analytical Expression ◽  
Planetary Gear Trains ◽  
Input And Output ◽  
Approximate Relationship ◽  
Gear Trains

The objective of the present work is to determine the conditions that have to be satisfied for a planetary gear train of one degree of freedom to be self-locking. All planetary gear trains of up to six members are considered. As a result, we show the constructional solutions of planetary gear trains exhibiting self-locking. Unlike other studies, the self-locking conditions are obtained systematically from the analytical expression for the product of the efficiency of a given train by the efficiency of the train resulting from interchanging its input and output axes. Finally, a proof is given of an approximate relationship between these two efficiencies.

An Improved Harmony Search Algorithm for a Planar Parallel Robot Synthesis

2018 ◽  
Vol 35 ◽  
pp. 185-197
Author(s):  
Badreddine Aboulissane ◽  
Dikra El Haiek ◽  
Larbi El Bakkali
Keyword(s):  
Search Algorithm ◽  
Harmony Search ◽  
Parallel Robot ◽  
Harmony Search Algorithm ◽  
Path Generation ◽  
Motion Generation ◽  
Kinematic Synthesis ◽  
Design Variables ◽  
Joint Coordinates ◽  
Improved Harmony Search

The objective of kinematic synthesis is to determine the mechanism dimensions such as link lengths, positions or joint coordinates, in order to approximate its output parameters such as link positions, trajectory points, and displacement angles. Kinematic synthesis is classified into three categories: function generation, path generation, and motion generation. This paper is dedicated only to path generation. As the number of trajectory points increases, analytical methods are limited to obtain precisely mechanism solutions. In that case, numerical methods are more efficient to solve such problems. Our study proposes an improved heuristic algorithm applied to four-bar mechanism path-generation. The objective of this work is to find optimum dimensions of the mechanism and minimize the error between the generated trajectory and the desired one, taking into consideration constraints such as: Grashof condition, transmission angle, and design variables constraints. Finally, our results are compared with those found by other evolutionary algorithms in the literature.

Design of a High-Speed Spherical Four-Bar Mechanism for Use in a Motion Common in Assembly Processes

2007 ◽  
Author(s):  
Andrew P. Murray ◽  
Franc¸ois Pierrot
Keyword(s):  
Sensitivity Analysis ◽  
High Speed ◽  
Mechanical Design ◽  
Degree Of Freedom ◽  
Kinematic Synthesis ◽  
Control Scheme ◽  
Smooth Motion ◽  
Spherical Mechanism

In this paper, we present the mechanical design of a spherical four-bar mechanism for performing a motion common in manufacturing and assembly processes. The mechanism is designed to create, in a single, smooth motion, the combined rotation of a body by 90 degrees about one axis with a 90 degree rotation about an axis perpendicular to the first. A spherical four-bar mechanism is pursued as the basis for the design because the reorientation is produced mechanically rather than via a control scheme typical when higher degree of freedom systems are utilized. The design initiates with the kinematic synthesis of the spherical mechanism to guide a body through two orientations. The next step in the design is to refine the spherical fourbar based on manufacturing and operational concerns. As one of the challenges of utilizing these four-bars is tuning the starting and ending angle for the mechanism’s motion, a sensitivity analysis is performed to gauge the needed accuracy. Finally, there are details and a discussion of the proposed mechanical design.

Kinematic Synthesis of a Medical Bed for Decubitus Ulcer Patients

2003 ◽  
Author(s):  
Jae Kyung Shim ◽  
Chang Sup Shim ◽  
Jin Wook Kwon
Keyword(s):  
Soft Tissue ◽  
Pressure Ulcer ◽  
Decubitus Ulcer ◽  
Degree Of Freedom ◽  
Shear Forces ◽  
Kinematic Synthesis ◽  
Principal Factors ◽  
Left And Right ◽  
Time Reduction

A decubitus ulcer or bedsore is a pressure-induced ulceration of the skin occurring in persons confined to bed for long periods of time. Reduction of pressure over bony prominences is of primary importance to prevent and cure bedsores. For this purpose, specially designed mattresses can be used and/or the patient should be turned frequently to avoid ischemia of soft tissue. In addition to pressure, other principal factors causing bedsore are friction and shear forces. In this paper, we designed a new 5 degree of freedom bed mechanism that can be used to change the posture of pressure ulcer patients, which generates 7 motions including backrest elevation, kneerest elevation, lounge position, left and right rotation, trendelenberg and reverse trendelenberg motion, and straight elevation. Particularly, we focused on the synthesis of a backrest and seatrest assembly that can reduce sliding between the bed and the patient.

Kinematic Synthesis of Minimally Actuated Multi-Loop Planar Linkages With Second Order Motion Constraints for Object Grasping

2013 ◽  
Author(s):  
Gim Song Soh ◽  
Nina Robson
Keyword(s):  
Second Order ◽  
Human Robot Interaction ◽  
Degree Of Freedom ◽  
Dimensional Synthesis ◽  
Open Problems ◽  
Kinematic Synthesis ◽  
Human Environment ◽  
Kinematic Chains ◽  
Curvature Effects ◽  
Planar Linkages

In this paper, we consider the dimensional synthesis of one degree-of-freedom multi-loop planar linkages such that they do not violate normal direction and second order curvature constraints imposed by contact with objects. Our goal is in developing minimally actuated multi-loop mechanical devices for human-robot interaction, that is, devices whose tasks will happen in a human environment. Currently no systematic method exists for the kinematic synthesis of robotic fingers that incorporate multi-loop kinematic structure with second order task constraints, related to curvature. We show how to use these contact and curvature effects to formulate the synthesis equations for the design of a planar one-degree-of-freedom six-bar linkage. An example for the design of a finger that maintains a specified contact with an object, for an anthropomorphic task, is presented at the end of the paper. It is important to note, that the theoretical foundation presented in this paper, assists in solving some of the open problems of this field, providing preliminary results on the synthesis of kinematic chains with multi-loop topology and the use of novel task specifications that incorporate curvature constraints with future applications in grasping and object manipulation.

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