Kinematic Synthesis of Spatial in-Parallel Wire-Driven Mechanism With Six Degrees of Freedom With High Force Transmissibility

2000 ◽  
Author(s):  
Yukio Takeda ◽  
Hiroaki Funabashi
Keyword(s):  
Degrees Of Freedom ◽  
Force Transmission ◽  
Kinematic Synthesis ◽  
Parallel Wire ◽  
Six Degrees Of Freedom ◽  
Output Force ◽  
Transmission Index ◽  
Six Dof ◽  
Force Transmissibility ◽  
The Relationship

Abstract We propose an index for evaluating the force transmission characteristics in general N degree-of-freedom (dof) in-parallel wire-driven mechanisms (PWDMs) with N + 1 wires. The relationship between input force and output force in an N dof in-parallel actuated mechanism with only rigid links was used for defining the transmission index for a PWDM. The index has been applied to the kinematic synthesis of spatial six dof PWDM with seven wires, and novel PWDMs with high force transmissibility have been obtained.

New Indices for Optimal Design of Redundantly Actuated Parallel Manipulators

2016 ◽  
Vol 9 (1) ◽  
Author(s):  
Qinchuan Li ◽  
Ningbin Zhang ◽  
Feibo Wang
Keyword(s):  
Optimal Design ◽  
Degrees Of Freedom ◽  
Parallel Manipulators ◽  
Mean Value ◽  
Transmission Performance ◽  
Transmission Index ◽  
Redundantly Actuated ◽  
Lower Mobility ◽  
Six Dof ◽  
Force Transmissibility

Redundantly actuated parallel manipulators (PMs) receive growing interest due to their reduced singularity and enlarged workspace. This paper proposes new indices for optimal design and analysis of redundantly actuated PMs by evaluating their motion/force transmissibility. First, we proposed a method to extract a multi-DOF (degrees-of-freedom) redundantly actuated PM into several subsidiary one-DOF PMs with two or more actuators by locking some actuators in an ergodic manner. Then, a new index of output transmission performance is proposed by investigating the mean value of the instantaneous power produced by the multiple actuation wrenches and one twist of the moving platform of one-DOF PMs. A local transmission index (LTI) is defined as the minimum value of the index of output and input transmission performance. A global transmission index (GTI) is then established based on the LTI. The proposed LTI and GTI are coordinate-free and have clear physical interpretation. Finally, the validity and universality of the new indices are demonstrated by optimization and analysis of redundantly actuated lower-mobility PMs with extra articulated six-DOF or limited-DOF limbs.

Modeling and prototype experiment of a six-DOF parallel micro-manipulator with nano-scale accuracy

2014 ◽  
Vol 229 (14) ◽  
pp. 2611-2625
Author(s):  
Yi Dong ◽  
Feng Gao ◽  
Yi Yue
Keyword(s):  
Degrees Of Freedom ◽  
Experimental Result ◽  
Element Analysis ◽  
Six Degrees Of Freedom ◽  
Compliant Structure ◽  
Nano Scale ◽  
Stiffness Model ◽  
Micro Manipulator ◽  
Six Dof ◽  
The Relationship

This paper presents a high-accurate micro-manipulator featured with monolithic compliant structure, orthogonally arranged parallel mechanism and piezoelectric (PZT) actuation. 6-SPS mechanism is employed to provide six degrees of freedom (DOF), including three linear translations and three rotations. The kinematics and stiffness of the micro-manipulator is studied first in this paper. Then, the relationship between PZT nominal displacement and the end pose is derived. Aiming at achieving trajectories with nano-scale accuracy, a two-step strategy is proposed. Finite element analysis (FEA) is conducted to verify the kinematics and stiffness model. Finally, in order to demonstrate the performance of the micro-manipulator, experiments of typical trajectories are carried out. The experimental result shows that the proposed micro-manipulator is capable of achieving trajectories with nano-scale accuracy.

Motion/Force Transmissibility Based Performance Evaluation of a 6-DOF Parallel Robot With 2-DOF Active Joints

2018 ◽  
Author(s):  
Bin Mei ◽  
Fugui Xie ◽  
Xin-Jun Liu ◽  
Xuan Luo
Keyword(s):  
Performance Evaluation ◽  
Degrees Of Freedom ◽  
Evaluation Method ◽  
Parallel Robot ◽  
Parallel Robots ◽  
Six Degrees Of Freedom ◽  
Transmission Index ◽  
Force Transmissibility ◽  
Local Transmission ◽  
Active Joints

3-PP(Pa)S robot is a six degrees of freedom (DOFs) parallel mechanism with 2-DOF active planar joint. For the design and application of the 3-PP(Pa)S robot, it is essential to investigate the motion/force transmissibility of the robot. But previous studies of the motion/force transmissibility have mainly focused on the parallel robots with 1-DOF active joints and thus cannot be directly applied to the 3-PP(Pa)S robot. In this paper, input twist subspace, transmission wrench subspace and output twist subspace are investigated to build mathematical models of the twists and wrenches corresponding to the 2-DOF active planar joint. Afterwards, based on the previous established frame of the local transmission index, some extended performance evaluation indices are defined to describe the motion/force transmissibility of the 3-PP(Pa)S robot. On this basis, the singularity and motion/force transmissibility of this mechanism are investigated. The motion/force transmissibility evaluation method is meaningful and applicable for the 3-PP(Pa)S parallel robot with 2-DOF active joints and can be further applied to other mechanisms with multi-DOF active joints.

Mobility, Kinematic Analysis, and Dimensional Optimization of New Three-Degrees-of-Freedom Parallel Manipulator With Actuation Redundancy

2017 ◽  
Vol 9 (4) ◽  
Author(s):  
Lingmin Xu ◽  
Qinchuan Li ◽  
Ningbin Zhang ◽  
Qiaohong Chen
Keyword(s):  
Parallel Manipulator ◽  
Degrees Of Freedom ◽  
Parallel Manipulators ◽  
Force Transmission ◽  
Transmission Index ◽  
Prismatic Joints ◽  
Redundantly Actuated ◽  
Force Transmissibility ◽  
Solution Velocity ◽  
Three Degrees Of Freedom

Parallel manipulators (PMs) with redundant actuation are attracting increasing research interest because they have demonstrated improved stiffness and fewer singularities. This paper proposes a new redundantly actuated parallel manipulator that has three degrees-of-freedom (DOFs) and four limbs. The proposed manipulator is a 2UPR-2PRU parallel manipulator (where P represents an actuated prismatic joint, R represents a revolute joint, and U represents a universal joint) that is actuated using four prismatic joints; two of these joints are mounted on the base to reduce the movable mass. Mobility analysis shows that the moving platform has two rotational DOFs and one translational DOF. First, the inverse displacement solution, velocity, and singularity analyses are discussed. Next, the local transmission index (LTI) and the good transmission workspace are used to evaluate the motion/force transmissibility of the 2UPR-2PRU parallel manipulator. Finally, the parameter-finiteness normalization method (PFNM) is used to produce an optimal design that considers the good transmission workspace. It is thus shown that the motion/force transmission of the proposed manipulator is improved by optimizing the link parameters.

scholarly journals Optimum Seeking of Redundant Actuators for M-RCM 3-UPU Parallel Mechanism

2020 ◽  
Author(s):  
Chen Zhao ◽  
Jingke Song ◽  
Xuechan Chen ◽  
Ziming Chen ◽  
Huafeng Ding
Keyword(s):  
Parallel Mechanism ◽  
Degrees Of Freedom ◽  
Singularity Analysis ◽  
Universal Joint ◽  
Prismatic Joint ◽  
Transmission Index ◽  
Redundant Actuators ◽  
Force Transmissibility ◽  
Singular Configuration

Abstract This paper focuses on a 2R1T 3-UPU (U for universal joint and P for prismatic joint) parallel mechanism (PM) with two rotational and one translational (2R1T) degrees of freedom (DOFs) and the ability of multiple remote centers of motion (M-RCM). The singularity analysis based on the indexes of motion/force transmissibility and constraint shows that this PM has transmission singularity, constraint singularity, mixed singularity and limb singularity. To solve these singularproblems, the quantifiable redundancy transmission index (RTI) and the redundancy constraint index (RCI) are proposed for optimum seeking of redundant actuators for this PM. Then the appropriate redundant actuators are selected and the working scheme for redundant actuators near the corresponding singular configuration are given to help the PM go through the singularity.

Dynamics Simulation of a Six-DOF Tunnel Segment Erector for Tunnel Boring Machine Based on Virtual Prototype

2012 ◽  
Vol 251 ◽  
pp. 231-234
Author(s):  
Gang Li ◽  
Ya Dong Chen ◽  
Bo Wang ◽  
Wan Shan Wang
Keyword(s):  
Degrees Of Freedom ◽  
Tunnel Boring Machine ◽  
Virtual Prototype ◽  
Dynamics Simulation ◽  
Design Parameters ◽  
Six Degrees Of Freedom ◽  
Tunnel Boring ◽  
Six Dof ◽  
Freedom Movement ◽  
Segment Erector

In this paper, we present the modeling and dynamics simulation of a six-DOF tunnel segment erector for tunnel boring machine (TBM), which is performed in the virtual prototype platform. The 3D virtual assembling model of a tunnel segment erector is built based on Pro/E software according to its design parameters such as structure and size. After the interference inspection, the model is imported into ADAMS through the interface module of Mech/Pro. The model is simplified and optimized reasonably and various constraints are applied under variety working conditions. The results of simulation show that the design has six degrees of freedom movement capacity which meets the design requirements. At the same time the dynamics characteristics of drives and the forces of each part are obtained and they will provide a boundary condition for strength check and basis for the power system design which is important for the further optimal design.

General inverse solution of six-degrees-of-freedom serial robots based on the product of exponentials model

2018 ◽  
Vol 38 (3) ◽  
pp. 361-367 ◽  
Author(s):  
Haixia Wang ◽  
Xiao Lu ◽  
Wei Cui ◽  
Zhiguo Zhang ◽  
Yuxia Li ◽  
...  
Keyword(s):  
Design Methodology ◽  
Degrees Of Freedom ◽  
Screw Theory ◽  
Complex Problem ◽  
Content Type ◽  
Geometrical Properties ◽  
Closed Form Solutions ◽  
Six Degrees Of Freedom ◽  
Serial Robots ◽  
Six Dof

Purpose Developing general closed-form solutions for six-degrees-of-freedom (DOF) serial robots is a significant challenge. This paper thus aims to present a general solution for six-DOF robots based on the product of exponentials model, which adapts to a class of robots satisfying the Pieper criterion with two parallel or intersecting axes among its first three axes. Design/methodology/approach The proposed solution can be represented as uniform expressions by using geometrical properties and a modified Paden–Kahan sub-problem, which mainly adopts the screw theory. Findings A simulation and experiments validated the correctness and effectiveness of the proposed method (general resolution for six-DOF robots based on the product of exponentials model). Originality/value The Rodrigues rotation formula is additionally used to turn the complex problem into a solvable trigonometric function and uniformly express six solutions using two formulas.

Kinematics of the Translational 3-URC Mechanism1

2004 ◽  
Vol 126 (6) ◽  
pp. 1113-1117 ◽  
Author(s):  
Raffaele Di Gregorio
Keyword(s):  
Explicit Form ◽  
Parallel Mechanism ◽  
Degrees Of Freedom ◽  
Industrial Applications ◽  
Parallel Architectures ◽  
Six Degrees Of Freedom ◽  
Spatial Mechanisms ◽  
Six Dof ◽  
And Control ◽  
Spherical Motion

The use of less than six degrees of freedom (dof) mechanisms instead of six-dof ones is always recommended when the application makes it possible, since their architectures and control are simpler to manufacture and implement respectively. Three-dof mechanisms constitute an important subset of less-than-six-dof mechanisms, since either translational or spherical motion can be obtained through three-dof spatial mechanisms and many industrial applications require the only translational or spherical motion. This paper presents a new translational parallel mechanism (TPM), named translational 3-URC. The new mechanism belongs to the parallel architectures with 3-URC topology, which contain another architecture that is a spherical parallel wrist. The proposed TPM is not overconstrained and has three equal legs whose kinematic pairs are three revolute pairs and one passive cylindrical pair per leg. Its actuated pairs are three revolute pair located on the frame. The position and velocity analyses of the translational 3-URC will be addressed and solved. Its singularity conditions will be written in explicit form and geometrically interpreted.

Motion/Force Transmission Analysis of Parallel Mechanisms With Planar Closed-Loop Subchains

2016 ◽  
Vol 138 (6) ◽  
Author(s):  
Kristan Marlow ◽  
Mats Isaksson ◽  
Jian S. Dai ◽  
Saeid Nahavandi
Keyword(s):  
Performance Measures ◽  
Parallel Mechanism ◽  
Degrees Of Freedom ◽  
Closed Loop ◽  
Screw Theory ◽  
Parallel Mechanisms ◽  
Force Transmission ◽  
Six Degrees Of Freedom ◽  
Lower Mobility ◽  
Transmission Ability

Singularities are one of the most important issues affecting the performance of parallel mechanisms. A parallel mechanism with less than six degrees of freedom (6DOF) is classed as having lower mobility. In addition to input–output singularities, such mechanisms potentially suffer from singularities among their constraints. Furthermore, the utilization of closed-loop subchains (CLSCs) may introduce additional singularities, which can strongly affect the motion/force transmission ability of the entire mechanism. In this paper, we propose a technique for the analysis of singularities occurring within planar CLSCs, along with a finite, dimensionless, frame invariant index, based on screw theory, for examining the closeness to these singularities. The integration of the proposed index with existing performance measures is discussed in detail and exemplified on a prototype industrial parallel mechanism.

General method for kinematic synthesis of manipulators with task specifications

Robotica ◽  
1997 ◽  
Vol 15 (6) ◽  
pp. 653-661 ◽  
Author(s):  
F.B. Ouezdou ◽  
S. Régnier
Keyword(s):  
Degrees Of Freedom ◽  
Inverse Kinematic ◽  
Synthesis Problem ◽  
Inverse Kinematic Problem ◽  
Kinematic Synthesis ◽  
Six Degrees Of Freedom ◽  
Cluttered Environment ◽  
Dimensional Parameters ◽  
Joint Limits ◽  
General Method

This paper deals with the kinematic synthesis of manipulators. A new method based on distributed solving is used to determine the dimensional parameters of a general manipulator which is able to reach a set of given tasks specified by orientation and position. First, a general Distributed Solving Method (DSM) is presented in three steps: the problem statement, the objective functions formulations and the minimum parameters values determination. Then, this method is applied to solve the synthesis of the Denavit and Hartenberg set of parameters of a manipulator with a given kinematic structure. In this case, the kind and the number of joints are specified and a set of constraints are included such as joint limits, range of dimensional parameters and geometrical obstacles avoidance. We show that if the Denavit and Hartenberg parameters (DH) are known, the synthesis problem is reduced to an inverse kinematic problem. We show also how the problem of robot base placement can be solved by the same method. A general algorithm is given for solving the synthesis problem for all kind of manipulators. The main contribution of this paper is a general method for kinematic synthesis of all kind of manipulators and some examples are presented for a six degrees of freedom manipulator in cluttered environment.

Sign in / Sign up

Export Citation Format

Share Document