scholarly journals Sensitivity Analysis of the Orthoglide, a 3-DOF Translational Parallel Kinematic Machine

2004 ◽  
Author(s):  
Ste´phane Caro ◽  
Philippe Wenger ◽  
Fouad Bennis ◽  
Damien Chablat
Keyword(s):  
Sensitivity Analysis ◽  
Kinematic Analysis ◽  
Design Parameters ◽  
Analysis Method ◽  
Parallel Kinematic Machine ◽  
Vector Method ◽  
End Effector ◽  
Singular Configurations ◽  
Parallel Kinematic ◽  
Position And Orientation

This paper presents a sensitivity analysis of the Orthoglide, a 3-DOF translational Parallel Kinematic Machine. Two complementary methods are used to analyze its sensitivity to its dimensional and angular variations. First, a linkage kinematic analysis method is used to have a rough idea of the influence of the dimensional variations on the location of the end-effector, and shows that the variations in design parameters of the same type from one leg to another one have the same influence on the end-effector. However, this method does not allow the designer to know the influence of the variations in the parallelograms. Thus, a differential vector method is used to study the influence of the dimensional and angular variations in the parts of the manipulator, and particularly the variations in the parallelograms, on the position and orientation of the end-effector. It turns out that the isotropic kinematic configuration of the manipulator is the least sensitive one to its geometrical variations, contrary to the closest configurations to its kinematic singular configurations, which are the most sensitive to geometrical variations.

scholarly journals Sensitivity Analysis of the Orthoglide: A Three-DOF Translational Parallel Kinematic Machine

2005 ◽  
Vol 128 (2) ◽  
pp. 392-402 ◽  
Author(s):  
Stéphane Caro ◽  
Philippe Wenger ◽  
Fouad Bennis ◽  
Damien Chablat
Keyword(s):  
Design Parameters ◽  
Analysis Method ◽  
Parallel Kinematic Machine ◽  
Vector Method ◽  
End Effector ◽  
Singular Configurations ◽  
Parallel Kinematic ◽  
Position And Orientation ◽  
The One ◽  
Three Degree Of Freedom

In this paper, two complementary methods are introduced to analyze the sensitivity of a three-degree-of-freedom (3-DOF) translational parallel kinematic machine (PKM) with orthogonal linear joints: the Orthoglide. Although these methods are applied to a particular PKM, they can be readily applied to 3-DOF Delta-Linear PKM such as ones with their linear joints parallel instead of orthogonal. On the one hand, a linkage kinematic analysis method is proposed to have a rough idea of the influence of the length variations of the manipulator on the location of its end-effector. On the other hand, a differential vector method is used to study the influence of the length and angular variations in the parts of the manipulator on the position and orientation of its end-effector. Besides, this method takes into account the variations in the parallelograms. It turns out that variations in the design parameters of the same type from one leg to another have the same effect on the position of the end-effector. Moreover, the sensitivity of its pose to geometric variations is a minimum in the kinematic isotropic configuration of the manipulator. On the contrary, this sensitivity approaches its maximum close to the kinematic singular configurations of the manipulator.

Error estimation and sensitivity analysis of the 3-UPU translational parallel robot due to design parameter uncertainties

2018 ◽  
Vol 233 (8) ◽  
pp. 2713-2727 ◽  
Author(s):  
S El Hraiech ◽  
AH Chebbi ◽  
Z Affi ◽  
L Romdhane
Keyword(s):  
Sensitivity Analysis ◽  
Vertical Axis ◽  
Parallel Robot ◽  
Design Parameters ◽  
Analysis Method ◽  
Parameter Uncertainties ◽  
End Effector ◽  
Interval Analysis Method ◽  
Influential Parameters ◽  
Kinematic Errors

This work deals with the estimation and the sensitivity analysis of the 3-UPU parallel robot error. Based on the Newton–Euler formalism, the robot dynamic model is given in a closed form. This model is validated by the software ADAMS. Using the interval analysis method, a new algorithm is proposed, which estimates the errors in the motion of the end-effector and the errors in the actuator forces as a function of the design parameters uncertainties. The obtained results show that the kinematic errors are minimal at the workspace center. Moreover, these errors increase as the platform moves along the vertical axis. It is also shown that kinematic errors in the actuator joints are the most influential parameters on the manipulator accuracy. Therefore, using actuators with a higher accuracy can highly reduce the errors in motion of the platform.

Error modeling and sensitivity analysis of a novel 5-degree-of-freedom parallel kinematic machine tool

2018 ◽  
Vol 233 (6) ◽  
pp. 1637-1652 ◽  
Author(s):  
Xuan Luo ◽  
Fugui Xie ◽  
Xin-Jun Liu ◽  
Jie Li
Keyword(s):  
Sensitivity Analysis ◽  
Machine Tool ◽  
Jacobian Matrix ◽  
Error Modeling ◽  
Degree Of Freedom ◽  
Geometric Errors ◽  
Parallel Kinematic Machine ◽  
Parallel Kinematic ◽  
Position And Orientation ◽  
Five Axis

5-Degree-of-freedom parallel kinematic machine tools are always attractive in manufacturing industry due to the ability of five-axis machining with high stiffness/mass ratio and flexibility. In this article, error modeling and sensitivity analysis of a novel 5-degree-of-freedom parallel kinematic machine tool are discussed for its accuracy issues. An error modeling method based on screw theory is applied to each limb, and then the error model of the parallel kinematic machine tool is established and the error mapping Jacobian matrix of 53 geometric errors is derived. Considering that geometric errors exert both impacts on value and direction of the end-effector’s pose error, a set of sensitivity indices and an easy routine for sensitivity analysis are proposed according to the error mapping Jacobian matrix. On this basis, 10 vital errors and 10 trivial errors are identified over the prescribed workspace. To validate the effects of sensitivity analysis, several numerical simulations of accuracy design are conducted, and three-dimensional model assemblies with relevant geometric errors are established as well. The simulations exhibit maximal −0.10% and 0.34% improvements of the position and orientation errors, respectively, after modifying 10 trivial errors, while minimal 65.56% and 55.17% improvements of the position and orientation errors, respectively, after modifying 10 vital errors. Besides the assembly reveals an output pose error of (0.0134 mm, 0.0020 rad) with only trivial errors, while (2.0338 mm, 0.0048 rad) with only vital errors. In consequence, both results of simulations and assemblies validate the correctness of the sensitivity analysis. Moreover, this procedure can be extended to any other parallel kinematic mechanisms easily.

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.

Kinematic Analysis and Simulation of the Translational Parallel Mechanism

2011 ◽  
Vol 213 ◽  
pp. 43-47 ◽  
Author(s):  
Dong Tao Xu ◽  
Zhi Li Sun ◽  
Jia Lian Shi
Keyword(s):  
Kinematic Analysis ◽  
Parallel Mechanism ◽  
Virtual Prototyping ◽  
Inverse Solution ◽  
Kinematic Modeling ◽  
Forward Solution ◽  
Vector Method ◽  
End Effector ◽  
Kinematic Simulation ◽  
Revolute Joints

This paper presents a novel, precision, maneuverable, 3-DOF translational parallel mechanism. The mechanism’s important feature is that all of the kinematic joints are the revolute joints. The paper derives the mechanism’s kinematic forward solution and inverse solution by using of coordinate transformation elimination method and vector method, and establishes proper kinematic modeling. Kinematic simulation is carried out by ADAMS virtual prototyping software. The operating data is obtained, it verifies the correctness of solving the forward and inverse solution, and solve the question of choices for many results during the theoretical solution. This technique can provide a useful tool in the design of kinematic trajectory of the parallel mechanism’s end-effector and the kinematic analysis of other parallel mechanism.

A new parallel wrist using only revolute pairs: the 3-RUU wrist

Robotica ◽  
2001 ◽  
Vol 19 (3) ◽  
pp. 305-309 ◽  
Author(s):  
Raffaele Di Gregorio
Keyword(s):  
Explicit Form ◽  
Kinematic Analysis ◽  
Degrees Of Freedom ◽  
Geometric Errors ◽  
End Effector ◽  
Singular Configurations ◽  
Overconstrained Mechanisms ◽  
Three Degrees Of Freedom

Only one parallel wrist with three equal legs containing just revolute pairs has been already presented in the literature. This parallel wrist is overconstrained, i.e., it involves three degrees of freedom required to orientate the end effector by using repetitions of constraints. The overconstrained mechanisms have the drawback of jamming or undergoing high internal loads when geometric errors occur. This paper presents a new parallel wrist, named 3-RUU wrist. The 3-RUU wrist is not overconstrained. It has three equal legs just involving revolute pairs and actuators adjacent to the frame and uses an architecture (3-RUU) already employed to obtain manipulators that make the end effector translate. The 3-RUU wrist kinematic analysis is addressed. This analysis shows that the new parallel wrist can reach singular configurations (translation singularities) in which the spherical constraint between end effector and frame fails. The singularity condition that makes finding all the 3-RUU wrist singular configurations possible is written in explicit form and geometrically interpreted.

A New 4-DOF Fully Parallel Robot With Decoupled Rotation for Five-Axis Micromachining Applications

2019 ◽  
Vol 11 (3) ◽  
Author(s):  
Oleksandr Stepanenko ◽  
Ilian A. Bonev ◽  
Dimiter Zlatanov
Keyword(s):  
Degrees Of Freedom ◽  
Mechanical Design ◽  
Parallel Robot ◽  
Parallel Kinematic Machine ◽  
Constant Length ◽  
End Effector ◽  
Kinematic Models ◽  
Parallel Kinematic ◽  
Linear Actuators ◽  
Five Axis

We present a novel 4-DOF (degrees of freedom) parallel robot designed for five-axis micromachining applications. Two of its five telescoping legs operate simultaneously, thus acting as an extensible parallelogram linkage, and in conjunction with two other legs control the position of the tooltip. The fifth leg controls the tilt of the end-effector (a spindle), while a turntable fixed at the base of the robot controls the swivel of the workpiece. The robot is capable of tilting its end-effector up to 90 deg, for any tooltip position. In this paper, we study the mobility of the new parallel kinematic machine (PKM), describe its inverse and direct kinematic models, then study its singularities, and analyze its workspace. Finally, we propose a potential mechanical design for this PKM utilizing telescopic actuators as well as the procedure for optimizing it. In addition, we discuss the possibility of using constant-length legs and base-mounted linear actuators in order to increase the volume of the workspace.

Kinematic Analysis and Dimensional Synthesis of a New 2R1T Parallel Kinematic Machine

2018 ◽  
Author(s):  
Lingmin Xu ◽  
Xubiao Zhu ◽  
Wei Ye ◽  
Qinchuan Li ◽  
Qiaohong Chen
Keyword(s):  
Kinematic Analysis ◽  
Inverse Kinematics ◽  
Parallel Kinematic Machine ◽  
Dimensional Synthesis ◽  
Transmission Index ◽  
Fixed Base ◽  
Prismatic Joints ◽  
Force Transmissibility ◽  
Parallel Kinematic ◽  
Local Transmission

This paper deals with the kinematic analysis and dimensional synthesis of a new 2R1T (R: rotation, T: translation) parallel kinematic machine (PKM). This is a 2PRU-UPR (P, R, U standing for prismatic, revolute and universal joint, respectively) PKM that is actuated by three actuated prismatic joints, two of which are mounted on the fixed base to reduce the movable mass. Firstly, the mobility and inverse kinematics of the 2PRU-UPR PKM are proposed. And then the motion/force transmissibility is evaluated by the local transmission index and good transmission workspace. Moreover, the singular configurations are obtained according to the motion/force transmissibility. Dimensional synthesis is carried out based on the GTW, and the optimized architectural parameters with good GTW are obtained. Finally, a prototype based on the optimized parameters has been developed, which has great potential in machining workpieces with curved surfaces.

scholarly journals Kinematic Analysis and Trajectory Planning of the Orthoglide 5-Axis

2015 ◽  
Author(s):  
S. Caro ◽  
D. Chablat ◽  
P. Lemoine ◽  
P. Wenger
Keyword(s):  
Trajectory Planning ◽  
Kinematic Analysis ◽  
High Speed ◽  
Degrees Of Freedom ◽  
Kinematic Model ◽  
Inverse Kinematic ◽  
Hybrid Architecture ◽  
Parallel Kinematic Machine ◽  
Control Loop ◽  
Parallel Kinematic

The subject of this paper is about the kinematic analysis and the trajectory planning of the Orthoglide 5-axis. The Orthoglide 5-axis a five degrees of freedom parallel kinematic machine developed at IRCCyN and is made up of a hybrid architecture, namely, a three degrees of freedom translational parallel manipulator mounted in series with a two degrees of freedom parallel spherical wrist. The simpler the kinematic modeling of the Orthoglide 5-axis, the higher the maximum frequency of its control loop. Indeed, the control loop of a parallel kinematic machine should be computed with a high frequency, i.e., higher than 1.5 MHz, in order the manipulator to be able to reach high speed motions with a good accuracy. Accordingly, the direct and inverse kinematic models of the Orthoglide 5-axis, its inverse kinematic Jacobian matrix and the first derivative of the latter with respect to time are expressed in this paper. It appears that the kinematic model of the manipulator under study can be written in a quadratic form due to the hybrid architecture of the Orthoglide 5-axis. As illustrative examples, the profiles of the actuated joint angles (lengths), velocities and accelerations that are used in the control loop of the robot are traced for two test trajectories.

Constraint and Singularity Analysis of the Exechon Tripod

2012 ◽  
Author(s):  
Dimiter Zlatanov ◽  
Matteo Zoppi ◽  
Rezia Molfino
Keyword(s):  
Machine Tool ◽  
System Approach ◽  
Parallel Mechanism ◽  
Singularity Analysis ◽  
Geometric Interpretation ◽  
End Effector ◽  
Singular Configurations ◽  
Parallel Kinematic ◽  
Three Degree Of Freedom ◽  
Fixture System

The paper discusses mobility and singularities of the Exechon three-degree-of-freedom (dof) parallel mechanism (PM) on which a family of parallel kinematic machines is based. Exechon designs are used by a number of machine-tool makers. A new version of the manipulator has been developed as a component of a mobile self-reconfigurable fixture system within an inter-European project. The PM has two UPR (4-dof) legs, constrained to move in a common rotating plane, and an SPR (5-dof) leg. The paper focuses on the constraint and singularity analysis of the mechanism. The screw systems of end-effector freedoms and constraints are identified. The singular configurations are classified in detail and their geometric interpretation is discussed. The velocity kinematics and the Jacobian operator are formulated via a screw-system approach. A fully parameterized package of Maple tools has been developed and used to visualize singularities and their consequences.

Sign in / Sign up

Export Citation Format

Share Document