Design of a Linear Gravity Compensator for a Prismatic Joint

2020 ◽  
Author(s):  
Do-Won Kim ◽  
Won-Bum Lee ◽  
Jae-Bok Song
Keyword(s):  
Prismatic Joint ◽  
Gravity Compensator ◽  
Linear Gravity

scholarly journals Simulation of an Exoskeleton with a Hybrid Linear Gravity Compensator

2020 ◽  
Vol 24 (3) ◽  
pp. 66-78
Author(s):  
A. E. Karlov ◽  
A. A. Postolny ◽  
A. V. Fedorov ◽  
S. F. Jatsun
Keyword(s):  
Numerical Simulation ◽  
Mathematical Model ◽  
Differential Equations ◽  
Kinematic Model ◽  
Hybrid Approach ◽  
Second Order ◽  
System Parameters ◽  
Second Order Differential Equations ◽  
Gravity Compensator ◽  
Linear Gravity

Purpose of research. Development of a mathematical model of an exoskeleton equipped with a hybrid linear gravity compensator (HLGC), dynamic analysis on the example of a typical exoskeleton application scenario (in the process of lifting a load), obtaining time patterns of changes in system parameters, including electric drive torques allowing assessment of power plan power consumption and energy efficiency. The article deals with the challenging issue of improving the efficiency of the exoskeletal suit by means of HLGC. The use of a hybrid approach makes it possible to increase the efficiency of assisting the exoskeletal suit when performing various technological operations, for example, when lifting a load, when tilting and holding. Methods. When developing a mathematical model, an original approach was used to form the motion trajectory of the exoskeleton sectors during operation, based on the use of seventh-order polynomials. The paper uses a mathematical model represented by a system of second-order differential equations that connects the moments acting on the operator and the exoskeleton, the angular accelerations of the operator's back and the exoskeleton. Results. During numerical simulation, time diagrams of changes in system parameters, angles of rotation of exoskeleton hinges, moments that occur in a hybrid LGC, as well as graphs of current consumption of engines when performing lift and tilt with a load are obtained. Conclusion. In the course of the research, a kinematic model of an exoskeleton suit equipped with a GLGC was developed, second-order differential equations describing the dynamic behavior of the electromechanical system were written, and numerical simulation was performed to estimate the forces and energy consumption in the exoskeleton hinges and the drive of the hybrid linear gravity compensator.

Mobility of Single-Loop N-Bar Linkage With Active/Passive Prismatic Joints

2005 ◽  
Vol 128 (6) ◽  
pp. 1261-1271 ◽  
Author(s):  
W. Z. Guo ◽  
R. Du
Keyword(s):  
Open Loop ◽  
Class Iii ◽  
Active Joint ◽  
Revolute Joint ◽  
Single Loop ◽  
Prismatic Joint ◽  
Passive Joint ◽  
Offset Distance ◽  
Prismatic Joints ◽  
Planar Linkages

Single-loop N-bar linkages that contain one prismatic joint are common in engineering. This type of mechanism often requires complicated control and, hence, understanding its mobility is very important. This paper presents a systematic study on the mobility of this type of mechanism by introducing the concept of virtual link. It is found that this type of mechanism can be divided into three categories: Class I, Class II, and Class III. For each category, the slide reachable range is cut into different regions: Grashof region, non-Grashof region, and change-point region. In each region, the rotation range of the revolute joint or rotatability of the linkage can be determined based on Ting’s criteria. The characteristics charts are given to describe the rotatability condition. Furthermore, if the prismatic joint is an active joint, the revolvability of the input revolute joint is dependent in non-Grashof region but independent in other regions. If the prismatic joint is a passive joint, the revolvability of the input revolute joint is dependent on the offset distance of the prismatic joint. Two examples are given to demonstrate the presented method. The new method is able to cover all the cases of N-bar planar linkages with one or a set of adjoined prismatic joints. It can also be used to study N-bar open-loop planar robotic mechanisms.

Stiffness modeling of an industrial robot with a gravity compensator considering link weights

2021 ◽  
Vol 161 ◽  
pp. 104331
Author(s):  
Peng Xu ◽  
Xiling Yao ◽  
Shibo Liu ◽  
Hao Wang ◽  
Kui Liu ◽  
...  
Keyword(s):  
Industrial Robot ◽  
Stiffness Modeling ◽  
Gravity Compensator

Position analysis in polynomial form of planar mechanism with an Assur group of class 4 including one prismatic joint

2004 ◽  
Vol 39 (3) ◽  
pp. 237-245 ◽  
Author(s):  
S. Mitsi ◽  
K.-D. Bouzakis ◽  
G. Mansour
Keyword(s):  
Polynomial Form ◽  
Planar Mechanism ◽  
Prismatic Joint ◽  
Position Analysis ◽  
Assur Group

On the Seven Position Synthesis of a 5-SS Platform Linkage

1997 ◽  
Vol 123 (1) ◽  
pp. 74-79 ◽  
Author(s):  
Qizheng Liao ◽  
J. Michael McCarthy
Keyword(s):  
Rigid Body ◽  
Reference Point ◽  
Polynomial Solution ◽  
Degree Of Freedom ◽  
Prismatic Joint ◽  
Movement Characteristics ◽  
Position Synthesis ◽  
Freedom Movement

This paper builds on Innocenti’s polynomial solution for the 5-SS platform that generates a one-degree of freedom movement through seven specified spatial positions of a rigid body. We show that his 60×60 resultant can be reduced to one that is 10×10. We then actuate the linkage using a prismatic joint on the sixth leg and determine the trajectory of the reference point through the specified positions. The singularity submanifold of this associated 6-SS platform provides information about the movement characteristics of the 5-SS linkage.

scholarly journals Study on Design of Heavy Payload Robot Considering Design Factor of Gravity Compensator

2019 ◽  
Vol 18 (5) ◽  
pp. 23-28 ◽  
Author(s):  
Do-Seung Lee ◽  
◽  
Ho-Su Lee ◽  
Sang-Hun Pyo ◽  
Jung-Won Yoon ◽  
...  
Keyword(s):  
Design Factor ◽  
Gravity Compensator
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