Force analysis of the redundantly actuated parallel mechanism 2RPR+P considering different control methodologies

2021 ◽  
pp. 103783
Author(s):  
Yundou Xu ◽  
Ze Jiang ◽  
Zhongjin Ju ◽  
Zengzhao Wang ◽  
Wenlan Liu ◽  
...  
Keyword(s):  
Parallel Mechanism ◽  
Force Analysis ◽  
Redundantly Actuated

Repelling-Screw Based Force Analysis of Origami Mechanisms

2016 ◽  
Vol 8 (3) ◽  
Author(s):  
Chen Qiu ◽  
Ketao Zhang ◽  
Jian S. Dai
Keyword(s):  
Parallel Mechanism ◽  
Screw Theory ◽  
Reaction Force ◽  
Theoretical Background ◽  
Force Analysis ◽  
Modeling Approach ◽  
Reaction Forces ◽  
Redundantly Actuated

This paper provides an approach to model the reaction force of origami mechanisms when they are deformed. In this approach, an origami structure is taken as an equivalent redundantly actuated mechanism, making it possible to apply the forward-force analysis to calculating the reaction force of the origami structure. Theoretical background is provided in the framework of screw theory, where the repelling screw is introduced to integrate the resistive torques of folded creases into the reaction-force of the whole origami mechanism. Two representative origami structures are then selected to implement the developed modeling approach, as the widely used waterbomb base and the waterbomb-based integrated parallel mechanism. With the proposed kinematic equivalent, their reaction forces are obtained and validated, presenting a ground for force analysis of origami-inspired mechanisms.

Kinematic Analysis of a Novel 3-DOF Parallel Mechanism with Actuation Redundancy

2013 ◽  
Vol 816-817 ◽  
pp. 821-824
Author(s):  
Xue Mei Niu ◽  
Guo Qin Gao ◽  
Zhi Da Bao
Keyword(s):  
Kinematic Analysis ◽  
Parallel Mechanism ◽  
Rbf Neural Network ◽  
Analysis Method ◽  
Parallel Kinematic Mechanism ◽  
Redundantly Actuated ◽  
Parallel Kinematic ◽  
Forward Kinematic ◽  
Kinematic Mechanism ◽  
Kinematic Solution

Kinematic analysis plays an important role in the research of parallel kinematic mechanism. This paper addresses a novel forward kinematic solution based on RBF neural network for a novel 2PRRR-PPRR redundantly actuated parallel mechanism. Simulation results illustrate the validity and feasibility of the kinematic analysis method.

Analysis of a mechanism with redundant drive for antenna pointing

2016 ◽  
Vol 231 (2) ◽  
pp. 229-239 ◽  
Author(s):  
Xin Li ◽  
Xilun Ding ◽  
Gregory S Chirikjian
Keyword(s):  
Inverse Kinematics ◽  
Parallel Mechanism ◽  
Numerical Examples ◽  
Pointing Device ◽  
Key Factor ◽  
Rotary Motors ◽  
Redundantly Actuated ◽  
Pointing Accuracy ◽  
Forward And Inverse Kinematics ◽  
Redundant Drive

Orientation accuracy is a key factor in the design of mechanisms for antenna pointing. Our design uses a redundantly actuated parallel mechanism which may provide an effective way to solve this problem, and even can increase its payload capability and reliability. The presented mechanism can be driven by rotary motors fixed on the base to reduce the inertia of the moving parts and to lower the power consumption. The mechanism is redundantly actuated by three arms, and is used as a two-dimensional antenna tracking and pointing device. Both the forward and inverse kinematics are investigated to find all the possible solutions. Detailed characters of the platform are analyzed to demonstrate the advantages in eliminating singularities and improving pointing accuracy. A method of calculating the overconstrained orientational error is also proposed based on the differential kinematics. All the methods are verified by numerical examples.

Design and analysis of a redundantly actuated parallel mechanism for rapid machining

2001 ◽  
Vol 17 (4) ◽  
pp. 423-434 ◽  
Author(s):  
Jongwon Kim ◽  
Frank Chongwoo Park ◽  
Sun Joong Ryu ◽  
Jinwook Kim ◽  
Jae Chul Hwang ◽  
...  
Keyword(s):  
Parallel Mechanism ◽  
Redundantly Actuated

Kinematic Calibration for Redundantly Actuated Parallel Mechanisms

2004 ◽  
Vol 126 (2) ◽  
pp. 307-318 ◽  
Author(s):  
Jay il Jeong ◽  
Dongsoo Kang ◽  
Young Man Cho ◽  
Jongwon Kim
Keyword(s):  
Optimization Algorithm ◽  
Parallel Mechanism ◽  
Kinematic Calibration ◽  
Parallel Mechanisms ◽  
Geometrical Constraint ◽  
Kinematic Parameters ◽  
Angle Error ◽  
Calibration Algorithm ◽  
Redundantly Actuated

We present a new kinematic calibration algorithm for redundantly actuated parallel mechanisms, and illustrate the algorithm with a case study of a planar seven-element 2-degree-of-freedom (DOF) mechanism with three actuators. To calibrate a nonredundantly actuated parallel mechanism, one can find actual kinematic parameters by means of geometrical constraint of the mechanism’s kinematic structure and measurement values. However, the calibration algorithm for a nonredundant case does not apply for a redundantly actuated parallel mechanism, because the angle error of the actuating joint varies with position and the geometrical constraint fails to be consistent. Such change of joint angle error comes from constraint torque variation with each kinematic pose (meaning position and orientation). To calibrate a redundant parallel mechanism, one therefore has to consider constraint torque equilibrium and the relationship of constraint torque to torsional deflection, in addition to geometric constraint. In this paper, we develop the calibration algorithm for a redundantly actuated parallel mechanism using these three relationships, and formulate cost functions for an optimization algorithm. As a case study, we executed the calibration of a 2-DOF parallel mechanism using the developed algorithm. Coordinate values of tool plate were measured using a laser ball bar and the actual kinematic parameters were identified with a new cost function of the optimization algorithm. Experimental results showed that the accuracy of the tool plate improved by 82% after kinematic calibration in a redundant actuation case.

Geometry and Kinematic Analysis of a Redundantly Actuated Parallel Mechanism for Rehabilitation

2007 ◽  
Author(s):  
Jody A. Saglia ◽  
Jian S. Dai
Keyword(s):  
Control System ◽  
Kinematic Analysis ◽  
Parallel Mechanism ◽  
Parallel Manipulator ◽  
Jacobian Matrix ◽  
Forward Kinematics ◽  
Control System Design ◽  
Ankle Rehabilitation ◽  
Redundantly Actuated ◽  
Moving Platform

This paper presents the geometry and the kinematic analysis of a parallel manipulator developed for ankle rehabilitation, as the beginning of a control system design process. First the geometry of the parallel mechanism is described, secondly the equations for the inverse and the forward kinematics are obtained, then the forward kinematics is analyzed in order to define all the possible configurations of the moving platform. Finally the Jacobian matrix of the rig is obtained by differentiating the position equations and the singularities are investigated, comparing the non-redundant and redundant type of mechanism.

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