Kinematic analysis of overconstrained manipulators with partial subspaces using decomposition method

Robotica ◽  
2021 ◽  
pp. 1-16
Author(s):  
Özgün Selvi

SUMMARY Overconstrained manipulators in lower subspaces with unique motions can be created and analyzed. However, far too little attention has been paid to creating a generic method for overconstrained manipulators kinematic analysis. This study aimed to evaluate a generic methodology for kinematic analysis of overconstrained parallel manipulators with partial subspaces (OPM-PS) using decomposition to parallel manipulators (PMs) in lower subspaces. The theoretical dimensions of the method are depicted, and the use of partial subspace for overconstrained manipulators is portrayed. The methodology for the decomposition method is described and exemplified by designing and evaluating the method to two overconstrained manipulators with 5 degrees of freedom (DoF) and 3 DoF. The inverse kinematic analysis is detailed with position analysis and Jacobian along with the inverse velocity analysis. The workspace analysis for the manipulators using the methodology is elaborated with numerical results. The results of the study show that OPM-PS can be decomposed into PMs with lower subspace numbers. As imaginary joints are being utilized in the proposed methodology, it will create additional data to consider in the design process of the manipulators. Thus, it becomes more beneficial in design scenarios that include workspace as an objective.

Author(s):  
Zhen Gao ◽  
Dan Zhang

In this paper, a new 4UPS+PU redundantly actuated parallel manipulator is proposed. This mechanism possesses three degrees of freedom (DOF), one translation and two rotations. Different from general parallel manipulators, a passive leg is connected to both centers of the base and the moving platform to constrain the unwanted motion. The mobility study and inverse kinematic analysis are conducted. The reachable workspace is generated with boundary-searching based discretization method. The local and global performance indices including stiffness and dexterity and their atlas are investigated in details. Comprehensive simulation of kinematics, dynamics and proportional-integral-derivative (PID) position control are implemented based on Adams to evaluate and testify the high operational capacity and well motion characteristics.


2011 ◽  
Vol 101-102 ◽  
pp. 685-688 ◽  
Author(s):  
Meng Guan ◽  
Yi Min Song ◽  
Tao Sun ◽  
Gang Dong

This paper presents a novel 4-DOF (Degree of Freedom) parallel manipulator called 2-PSS&(2-PRR)R manipulator. Firstly, the architecture of this manipulator is described and the mobility is analyzed via screw theory. Secondly, the inverse kinematic analysis including position analysis and velocity analysis is performed. Finally, the Jacobian matrix is obtained through velocity analysis, and then three kinds of singularity configurations are observed in virtue of the Jacobian matrix. This paper lays the foundation for further research of this manipulator.


Author(s):  
Kemal Cem Kose ◽  
M Kemal Ozgoren ◽  
Ferzende Tekce ◽  
Nimeti Doner

This paper presents an original rehabilitative robotic walking simulation device. As a novel feature, it can duplicate the walking motion of the feet completely by including the motion of the metatarsophalangeal joints as well. It is also adjustable to different foot sizes and gait parameters such as speed, step length, and foot elevation. The presented device comprises two identical mechanisms that simulate the right and left feet. Each mechanism is designed as a planar parallel manipulator with three degrees of freedom and thus its platform (i.e. foot plate) can duplicate the sagittal-plane motion of a foot completely. A prototype of the device is already built, patented, and tested by several people, two of whom are physiotherapists. In the paper, the inverse and forward kinematic analyses of each parallel manipulator are also presented. The inverse kinematic analysis is carried out based on a typical gait cycle data of a healthy person gathered from the related literature. The results of the inverse kinematic analysis are then used as reference trajectory data in testing the device with different healthy people at different speeds.


2015 ◽  
Vol 8 (2) ◽  
Author(s):  
Andrew Johnson ◽  
Xianwen Kong ◽  
James Ritchie

The determination of workspace is an essential step in the development of parallel manipulators. By extending the virtual-chain (VC) approach to the type synthesis of parallel manipulators, this technical brief proposes a VC approach to the workspace analysis of parallel manipulators. This method is first outlined before being illustrated by the production of a three-dimensional (3D) computer-aided-design (CAD) model of a 3-RPS parallel manipulator and evaluating it for the workspace of the manipulator. Here, R, P and S denote revolute, prismatic and spherical joints respectively. The VC represents the motion capability of moving platform of a manipulator and is shown to be very useful in the production of a graphical representation of the workspace. Using this approach, the link interferences and certain transmission indices can be easily taken into consideration in determining the workspace of a parallel manipulator.


Author(s):  
Mazhar Ul Haq ◽  
Zhao Gang ◽  
Fazl E. Ahad ◽  
Anees Ur Rehman ◽  
Muhammad Hussain

In this paper, inverse kinematic analysis of a proposed three link mechanism of a bio-inspired micro scanning device towed underwater by a surface vessel to actuate its aileron fins for its depth control and for its stabilization against roll is performed. Mechanism is actuated by IPMC actuators. To speed up the design verification process, computer aided simulations are used to perform motion analysis of the proposed IPMC actuated mechanism through Pro/Mechanism tool. Inverse kinematic analysis is performed to find out the joint variables of the mechanism to realize fin actuation along desired path. Displacements, velocities and accelerations of the links constructing mechanism are found out to establish their interrelationship. Results are analysed for the study of mechanism efficacy and for sizing the IPMC actuators. This paper contributes to introduce a new approach of virtual prototyping using advanced simulation tools for analysis and design verification of IPMC actuated mechanisms for biomimetic applications before moving into functional prototype stage.


Author(s):  
Nathan A. Jensen ◽  
Carl A. Nelson

Abstract Underactuated parallel manipulators that achieve 6 DOF via multiple controllable degrees of freedom per leg are often pursued and reported due to their large workspaces. This benefit comes at a cost to the manipulator’s performance, however. Such manipulators must then be evaluated in order to characterize their kinematics in terms of position and motion. This paper establishes a pair of inverse kinematic solutions for a previously proposed and prototyped 3-leg, 6-DOF parallel robot. These solutions are then used to define the robot’s workspace with experimental validation and to optimize the robot’s geometry for maximum workspace volume. The linear components of the Jacobian are then defined, allowing for analysis of the manipulability of the robot. The full Jacobian is also defined, and singularities are examined throughout the workspace of the robot.


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