Control of six degree‐of‐freedom parallel manipulators for synchrotron radiation applications

1995 ◽  
Vol 66 (2) ◽  
pp. 1758-1761 ◽  
Author(s):  
P. Fajardo ◽  
V. Rey‐Bakaikoa
Keyword(s):  
Synchrotron Radiation ◽  
Parallel Manipulators ◽  
Degree Of Freedom ◽  
Six Degree Of Freedom

Determination of the Workspace of 6-DOF Parallel Manipulators

1989 ◽  
Author(s):  
C. Gosselin
Keyword(s):  
Parallel Manipulator ◽  
Graphical Representation ◽  
Three Dimensional ◽  
Parallel Manipulators ◽  
Degree Of Freedom ◽  
Geometrical Properties ◽  
Cartesian Space ◽  
Six Degree Of Freedom

Abstract This paper presents an algorithm for the determination of the workspace of parallel manipulators. The method described here, which is based on geometrical properties of the workspace, leads to a simple graphical representation of the regions of the three-dimensional Cartesian space that are attainable by the manipulator with a given orientation of the platform. Moreover, the volume of the workspace can be easily computed by performing an integration on its boundary, which is obtained from the algorithm. Examples are included to illustrate the application of the method to a six-degree-of-freedom fully-parallel manipulator.

A New Method to Calculate the Force and Moment Workspaces of Actuation Redundant Spatial Parallel Manipulators

2009 ◽  
Vol 1 (3) ◽  
Author(s):  
Venus Garg ◽  
Juan A. Carretero ◽  
Scott B. Nokleby
Keyword(s):  
Three Dimensional ◽  
Parallel Manipulators ◽  
Degree Of Freedom ◽  
New Method ◽  
Task Planning ◽  
Cartesian Space ◽  
Redundantly Actuated ◽  
Six Degree Of Freedom

A new method for obtaining the force and moment workspaces of spatial parallel manipulators (PMs) is presented. Force and moment workspaces are regions within which a manipulator can sustain/apply at least a certain value of force or moment in all directions. Here, the force and moment workspaces are found using a method, which explicitly sets the largest possible number of actuators to their maximum limits ensuring that the manipulator is performing at its best possible wrench capabilities. Two cases for obtaining these workspaces are used. The first gives the applicable/sustainable force with a prescribed moment whereas the second one gives the applicable/sustainable moment with a prescribed force. For illustration purposes, the method is applied to a six-degree-of-freedom (DOF) redundantly-actuated spatial PM, the 3-RRṞS. The results are represented graphically as the boundaries of the workspace in the three-dimensional Cartesian space. These workspaces can be used as a powerful tool for path/task planning and PM design.

Complete parameter identification of parallel manipulators with partial pose information using a new measurement device

Robotica ◽  
2004 ◽  
Vol 22 (6) ◽  
pp. 689-695 ◽  
Author(s):  
Abdul Rauf ◽  
Sung-Gaun Kim ◽  
Jeha Ryu
Keyword(s):  
Parallel Manipulators ◽  
Error Reduction ◽  
Initial Guess ◽  
Significant Error ◽  
Degree Of Freedom ◽  
Kinematic Parameters ◽  
Measurement Device ◽  
End Effector ◽  
Six Degree Of Freedom ◽  
Noisy Measurements

A new measurement device is proposed for the calibration of parallel manipulators that can be used to indentify all kinematic parameters with partial pose measurements. The device while restricting the motion of the end-effector to five degree-of-freedom measures three components of posture. A study is performed for a six degree-of-freedom fully parallel Hexa Slide Manipulator. Intrinsic inaccuracies of the measurement device are modeled with two additional identification parameters. Computer simulations show that all parameters, including the additional parameters, can be identified. Results show a significant error reduction, even with noisy measurements, and reveal that the identification is robust against errors in initial guess.

Analysis and Design of a Three-Limb Six Degree-of-Freedom Parallel Micromanipulator With Flexure Hinges

2007 ◽  
Author(s):  
Lefeng Wang ◽  
Weibin Rong ◽  
Lining Sun ◽  
Jie Jiao
Keyword(s):  
Compliant Mechanisms ◽  
Base Plate ◽  
Parallel Manipulators ◽  
Degree Of Freedom ◽  
Influence Coefficient ◽  
Analysis And Design ◽  
Flexure Hinges ◽  
Stiffness Model ◽  
Position Controller ◽  
Six Degree Of Freedom

A novel three-limb six degree-of-freedom (DOF) parallel micromanipulator with flexure hinges driven by piezoelectric actuators is presented. Its uniqueness lies in three inextensible limbs with specified flexure hinges and driving its input motions from a monolithic base plate that consists of three 2-DOF compliant mechanisms, unlike of the most six-limb parallel manipulators. The manipulator is very compact and its structure is simple. The kinematic problem of the manipulator is solved by using the kinematic influence coefficient theory. As a result, the velocities of the movable platform, the limbs and the flexure hinges are derived. The stiffness model of the micromanipulator is determined considering the elastic deformations of the flexure hinges according to the virtue work principle. The design targets and the primary design principles of the flexure hinges are discussed and the precision position controller modules are used to control the micromanipulator. At last the basic experiment results are presented.

Optimization Design of a Spatial Six-Degree-of-Freedom Parallel Manipulator Based on Genetic Algorithms and Neural Networks

2008 ◽  
Author(s):  
Dan Zhang ◽  
Zhen Gao
Keyword(s):  
Neural Networks ◽  
Genetic Algorithms ◽  
Parallel Manipulator ◽  
Optimization Design ◽  
Optimal Solution ◽  
Parallel Manipulators ◽  
Degree Of Freedom ◽  
Objective Functions ◽  
Kinetostatic Model ◽  
Six Degree Of Freedom

Optimizing the performances of parallel manipulators by adjusting the structure parameters can be a difficult and time-consuming exercise especially when the parameters are multifarious and the objective functions are too complex. Artificial intelligence approaches can be investigated as the effective criteria to address this issue. In this paper, genetic algorithms and artificial neural network are implemented as the intelligent optimization criteria of global stiffness and dexterity for spatial six degree-of-freedom (DOF) parallel manipulator. The objective functions of global stiffness and dexterity are calculated and deduced according to the kinetostatic model. Neural networks are utilized to model the solutions of performance indices. Multi-objective optimization is developed by Pareto-optimal solution. The effectiveness of the proposed methodology is proved by simulation.

Parallel Computational Algorithms for the Kinematics and Dynamics of Planar and Spatial Parallel Manipulators

1996 ◽  
Vol 118 (1) ◽  
pp. 22-28 ◽  
Author(s):  
C. M. Gosselin
Keyword(s):  
Inverse Kinematics ◽  
Parallel Manipulator ◽  
Inverse Dynamics ◽  
Parallel Manipulators ◽  
Degree Of Freedom ◽  
Kinematic Chains ◽  
Novel Approach ◽  
Judicious Choice ◽  
Six Degree Of Freedom ◽  
Three Degree Of Freedom

This paper introduces a novel approach for the computation of the inverse dynamics of parallel manipulators. It is shown that, for this type of manipulator, the inverse kinematics and the inverse dynamics procedures can be easily parallelized. The result is a closed-form efficient algorithm using n processors, where n is the number of kinematic chains connecting the base to the end-effector. The dynamics computations are based on the Newton-Euler formalism. The parallel algorithm arises from a judicious choice of the coordinate frames attached to each of the legs, which allows the exploitation of the parallel nature of the mechanism itself. Examples of the application of the algorithm to a planar three-degree-of-freedom parallel manipulator and to a spatial six-degree-of-freedom parallel manipulator are presented.

Determination of the Workspace of 6-DOF Parallel Manipulators

1990 ◽  
Vol 112 (3) ◽  
pp. 331-336 ◽  
Author(s):  
C. Gosselin
Keyword(s):  
Parallel Manipulator ◽  
Graphical Representation ◽  
Three Dimensional ◽  
Parallel Manipulators ◽  
Degree Of Freedom ◽  
Geometrical Properties ◽  
Cartesian Space ◽  
Six Degree Of Freedom

This paper presents an algorithm for the determination of the workspace of parallel manipulators. The method described here, which is based on geometrical properties of the workspace, leads to a simple graphical representation of the regions of the three-dimensional Cartesian space that are attainable by the manipulator with a given orientation of the platform. Moreover, the volume of the workspace can be easily computed by performing an integration in its boundary, which is obtained from the algorithm. Examples are included to illustrate the application of the method to a six-degree-of-freedom fully parallel manipulator.

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