Precision Analysis for the 3-PRS Parallel Robot

2012 ◽  
Vol 490-495 ◽  
pp. 495-498
Author(s):  
Shi Jie Hu
Keyword(s):  
Closed Loop ◽  
Parallel Robot ◽  
Differential Method ◽  
Error Model ◽  
Vector Model ◽  
Kinematics Analysis ◽  
Precision Analysis ◽  
Position And Orientation ◽  
Forward Error

The precision analysis of a 3-PRS parallel robot with three DOFs has been studied in this paper. The 3-PRS parallel robot has been introduced with its kinematics analysis. The closed-loop vector model has been introduced. By the differential method, the mathematic error model of the position and orientation has been built. The forward error solution has been deduced including all the structural errors. Given the structural errors, the output errors of the parallel robot can be solved by the introduced model. The effect of the variation of the position and orientation of the 3-PRS on the output errors of the parallel robot have been analyzed

Conceptual design and error analysis of a cable-driven parallel robot

Robotica ◽  
2021 ◽  
pp. 1-16
Author(s):  
Jiaxuan Li ◽  
Yongjie Zhao ◽  
Qingqiong Tang ◽  
Wei Sun ◽  
Feifei Yuan ◽  
...  
Keyword(s):  
Error Analysis ◽  
Conceptual Design ◽  
Parallel Robot ◽  
Error Component ◽  
Differential Method ◽  
Error Modeling ◽  
Geometric Errors ◽  
Kinematics Analysis ◽  
Orientation Error ◽  
Base Platform

Abstract This paper develops the conceptual design and error analysis of a cable-driven parallel robot (CDPR). The earlier error analysis of CDPRs generally regarded the cable around the pulley as a center point and neglected the radius of the pulleys. In this paper, the conceptual design of a CDPR with pulleys on its base platform is performed, and an error mapping model considering the influence of radius of the pulleys for the CDPR is established through kinematics analysis and a full matrix complete differential method. Monte Carlo simulation is adopted to deal with the sensitivity analysis, which can directly describe the contribution of each error component to the total orientation error of the CDPR by virtue of the error modeling. The results show that the sensitivity coefficients of pulleys’ geometric errors and geometric errors of the cables are relatively larger, which confirms that the cable length errors and pulleys’ geometric errors should be given higher priority in design and processing.

Parameterization of Three-Dimensional Rigid Body Guidance Incorporating Planar Gear Connections in a Spatial Closed-Loop Mechanism With Parallel Consecutive Axes

2008 ◽  
Author(s):  
Javier Rolda´n Mckinley ◽  
Carl Crane ◽  
David B. Dooner
Keyword(s):  
Computer Animation ◽  
Closed Loop ◽  
Three Dimensional ◽  
Motion Generation ◽  
Repetitive Motion ◽  
End Effector ◽  
Spatial Mechanism ◽  
Joint Axis ◽  
Position And Orientation ◽  
Six Degree Of Freedom

This paper introduces a reconfigurable closed-loop spatial mechanism that can be applied to repetitive motion tasks. The concept is to incorporate five pairs of non-circular gears into a six degree-of–freedom closed-loop spatial chain. The gear pairs are designed based on given mechanism parameters and a user defined motion specification of a coupler link of the mechanism. It is shown in the paper that planar gear pairs can be used if the spatial closed-loop chain is comprised of six pairs of parallel joint axes, i.e. the first joint axis is parallel to the second, the third is parallel to the fourth, ..., and the eleventh is parallel to the twelfth. This paper presents the synthesis of the gear pairs that satisfy a specified three-dimensional position and orientation need. Numerical approximations were used in the synthesis the non-circular gear pairs by introducing an auxiliary monotonic parameter associated to each end-effector position to parameterize the motion needs. The findings are supported by a computer animation. No previous known literature incorporates planar non-circular gears to fulfill spatial motion generation needs.

scholarly journals Kinematic Analysis of Three-Wire-Driven Parallel (TWDP) Robot

2011 ◽  
Vol 2-3 ◽  
pp. 302-307 ◽  
Author(s):  
Tao Yu ◽  
Qing Kai Han
Keyword(s):  
Static Analysis ◽  
Parallel Robot ◽  
Analytical Models ◽  
Kinematics Analysis ◽  
Mechanism Model ◽  
Good Movement ◽  
Dynamics And Control ◽  
Movement Stability ◽  
Simulation Results ◽  
And Control

In the paper, a novel new gravity-constrained (GC) three-wire-driven (TWD) parallel robot is proposed. With its mechanism model, three typical kinematics analytical models, including horizontal up-down motion, pitching motion and heeling motion and their corresponding simulations are given in detail. In static analysis, the change of tensions in the wires is calculated based on previous kinematics analysis. The simulation results show the robot has good movement stability. The paper can provide useful materials to study of dynamics and control on wire-driven robot.

Pose Accuracy Analysis of Robot Manipulators Based on Kinematics

2011 ◽  
Vol 201-203 ◽  
pp. 1867-1872 ◽  
Author(s):  
Jian Ye Zhang ◽  
Chen Zhao ◽  
Da Wei Zhang
Keyword(s):  
Matrix Theory ◽  
Robot Manipulators ◽  
Error Model ◽  
Robot Kinematics ◽  
Accuracy Analysis ◽  
Serial Link ◽  
End Effector ◽  
Surface Graph ◽  
Position And Orientation ◽  
Kinematics Parameters

The pose accuracy of robot manipulators has long become a major issue to be considered in its advanced application. An efficient methodology to generate the end-effector position and orientation error model of robotic manipulator has been proposed based on the differential transformation matrix theory. According to this methodology, a linear error model that described the end-effector position and orientation errors due to robot kinematics parameters errors has been presented. A computer program to generate the error model and perform the accuracy analysis on any serial link manipulator has been developed in MATLAB. This methodology and software are applied to the accuracy analysis of a Phantom Desktop manipulator. The positioning error of the manipulator in its workspace cross section (XOZ) has been plotted as 3D surface graph and discussed.

Error Comparison and Analysis of Parallel and Constraint Mechanism for 3-TPS Hybrid Machine Tool

2011 ◽  
Vol 127 ◽  
pp. 277-282
Author(s):  
Peng Fei Dang ◽  
Li Jin Fang
Keyword(s):  
Machine Tool ◽  
Parallel Mechanism ◽  
Parallel Robot ◽  
Error Model ◽  
Position Error ◽  
Robot Kinematics ◽  
Motion Error ◽  
Movable Plate ◽  
Hybrid Machine Tool ◽  
Hybrid Machine

This paper establishes position error model based on parallel robot kinematics theory, and analyses position error of the 3-TPS hybrid machine tool. Firstly, to calculate position error of the movable plate caused by the parallel mechanism links, through error model of the parallel mechanism which is established through inverse kinematics of the hybrid machine tool. Then, according to the error model of constraint mechanism established by transformation matrix method, the position error has been simulated and calculated. Finally, this paper compares the effects of both mechanisms. The analysis indicates the link error of constraint mechanism has more influence on movable plate posture than parallel mechanism, and provides help with motion error compensation and kinematic calibration.

Static Balancing of a Parallel Kinematics Machine With Linear-Delta Architecture

2014 ◽  
Author(s):  
Alberto Martini ◽  
Marco Troncossi ◽  
Marco Carricato ◽  
Alessandro Rivola
Keyword(s):  
General Theory ◽  
Closed Loop ◽  
Parallel Robot ◽  
Design Solution ◽  
Robot Design ◽  
Gravity Compensation ◽  
Parallel Kinematics ◽  
Static Balancing ◽  
Milling Operation ◽  
Working Performance

The study deals with the compensation of gravity loads in closed-loop mechanisms as a possible strategy for enhancing their working performance. This work focuses on the Orthoglide 5-axis, a prototypal parallel robot for milling operation, characterized by linear-delta architecture with two further serial DOFs. Starting from a general theory formerly proposed by the authors, gravity compensation of the mechanism is analytically carried out. The statically balanced Orthoglide 5-axis can be obtained by installing on one leg a proper set of extension springs and a simple additional linkage. A feasible design solution for developing the device in practice is presented. The proposed balancing device can be implemented with minor modifications of the original robot design, thus appearing a profitable solution to be possibly extended to other machinery with similar architecture.

Error Analysis of 6-DOF Welding Robot

2012 ◽  
Vol 220-223 ◽  
pp. 1111-1115
Author(s):  
Cai Dong Wang ◽  
Xin Jie Wang ◽  
Xue Dong Chen ◽  
Chao Hui Zhang
Keyword(s):  
High Efficiency ◽  
Manufacturing Sector ◽  
Differential Method ◽  
Error Model ◽  
Joint Movement ◽  
Welding Robot ◽  
Quality Stability ◽  
Robot Configuration ◽  
Six Degree Of Freedom ◽  
Robot Position

Welding robot has the advantages that welding quality stability, high efficiency, improving the working conditions of workers, and it is widely applied in the manufacturing sector. A six degree of freedom welding robot configuration is presented in this paper. The kinematics model of the robot is established by DH method and its kinematics was analyzed. At last the error model of the position-pose of the robot end-effecter, produced by the influence of robot joint movement variables deviation and structure deviation, was established by the differential method. The deviation influence on the end-effecter was analyzed by numerical simulation. The results prove the error model is right, and they will provide a reliable basis for robot position error compensation and accuracy optimum design.

Configuration Optimization of a Boat Simulation Platform for a Mobile User

2010 ◽  
Author(s):  
Juan C. Blanco ◽  
Carlos F. Rodri´guez
Keyword(s):  
Fitness Function ◽  
Center Of Mass ◽  
Parallel Robot ◽  
Mobile User ◽  
Simulation Platform ◽  
Motion Simulation ◽  
Objective Functions ◽  
Low Discrepancy Sequences ◽  
Position And Orientation ◽  
Mechanical Devices

Motion simulation platforms are mechanical devices designed to replicate the dynamics of a given vehicle. These devices are very attractive for training individuals as drivers, pilots or passengers. In the case of river boats, the simulator consists of a section of the boat (hull) mounted over a 3 DOF parallel robot with a passive mass compensator (3UPS + PU). If users have mobility in the hull, an uncertainty in the position of the upper platform’s center of mass is produced. This variation may generate excessive loads on the robot that can be prevented by an adequate placement of the hull over the robot. Dynamic calculations, based on measurements of the real boat in motion, are computed by numerical simulations in SimMechanics. Three methodologies are presented for optimizing the configuration of a boat simulation platform. First, a manual procedure is developed in which critical cases are intuitively detected and evaluated. Then, two multi-variable optimization algorithms are used to systematically obtain the best position and orientation (pose) of the boat section: Genetic Algorithms and low discrepancy sequences. The pose is the design variable; the average forces are the objective functions and the maximum difference between the average forces is the fitness function. The article describes the design problem, the proposed optimization methodologies and simulation results for the optimal configuration.

Research on Error Compensation by Semi-Closed Loop Control for a 3-UPS Parallel Machine Tool

2012 ◽  
Vol 461 ◽  
pp. 272-276
Author(s):  
Jian Ye Guo ◽  
Jia Shun Shi ◽  
Liang Zhao
Keyword(s):  
Machine Tool ◽  
Error Compensation ◽  
Closed Loop ◽  
Parallel Machine ◽  
Control Mode ◽  
Closed Loop Control ◽  
Kinematics Analysis ◽  
Compensation Strategy ◽  
Loop Control ◽  
Parallel Machine Tool

This paper took a 3-UPS Parallel Machine Tool (PMT) as the object of research; it mainly introduced the process of establishing the compensation strategy for this PMT. Firstly the kinematics equations on driving chain and constraint chain was established on the basis of kinematics analysis. Then according to the structural characteristics and the results of kinematics analysis, the error compensation strategy of feedback correction type with the semi-closed loop control mode was used in the error compensation for this PMT by the method of installing respectively the encoders on the each joint of parallelogram mechanism, namely the compensation way of “parallel driving and series feedback” was adopted. Finally this paper has also deduced the theoretical model of error compensation. The research results in this paper provided a theoretical basis for realizing error compensation of this PMT, and had important practical significance for improving machining precision of PMT

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