Synthesis and Design of a Novel 3T1R Fully-Parallel Manipulator

2008 ◽  
Vol 130 (4) ◽  
Author(s):  
Oscar Salgado ◽  
Oscar Altuzarra ◽  
Víctor Petuya ◽  
Alfonso Hernández
Keyword(s):  
Closed Form ◽  
Kinematic Analysis ◽  
Parallel Manipulator ◽  
Degrees Of Freedom ◽  
Parallel Manipulators ◽  
Singularity Analysis ◽  
Type Synthesis ◽  
Complete Type ◽  
Pick And Place ◽  
Schönflies Motion

In this paper a new topology of four degrees-of-freedom 3T1R fully-parallel manipulator is presented, which is defined only using lower kinematic pairs. The paper starts with a complete type synthesis of different topologies of fully-parallel manipulators that can perform the so-called Schönflies motion, based on the Theory of Groups of Displacements. After imposing some practical requirements, the different possibilities of manipulators are reduced to only one topology of fully-parallel and fully-symmetrical parallel manipulator. Then, the kinematic analysis of the manipulator is shown, including the closed-form resolution of both forward and inverse position problems, the velocity and the singularity analysis. Finally, a prototype of the manipulator is presented, which is intended to be used in pick and place applications.

On the kinematics of a new parallel mechanism with Schoenflies motion

Robotica ◽  
2015 ◽  
Vol 34 (9) ◽  
pp. 2056-2070 ◽  
Author(s):  
Po-Chih Lee ◽  
Jyh-Jone Lee
Keyword(s):  
Closed Form ◽  
Condition Number ◽  
Kinematic Analysis ◽  
Parallel Mechanism ◽  
Parallel Manipulator ◽  
Matrix Algebra ◽  
Degrees Of Freedom ◽  
Jacobian Matrix ◽  
Pick And Place

SUMMARYThis paper investigates the kinematics of one new isoconstrained parallel manipulator with Schoenflies motion. This new manipulator has four degrees of freedom and two identical limbs, each having the topology of Cylindrical–Revolute–Prismatic–Helical (C–R–P–H). The kinematic equations are derived in closed-form using matrix algebra. The Jacobian matrix is then established and the singularities of the robot are investigated. The reachable workspaces and condition number of the manipulator are further studied. From the kinematic analysis, it can be shown that the manipulator is simple not only for its construction but also for its control. It is hoped that the results of the evaluation of the two-limb parallel mechanism can be useful for possible applications in industry where a pick-and-place motion is required.

A Parallelogram-Based Parallel Manipulator for Schönflies Motion

2006 ◽  
Vol 129 (12) ◽  
pp. 1243-1250 ◽  
Author(s):  
Oscar Salgado ◽  
Oscar Altuzarra ◽  
Enrique Amezua ◽  
Alfonso Hernández
Keyword(s):  
Kinematic Analysis ◽  
Parallel Manipulator ◽  
Degrees Of Freedom ◽  
Kinematic Chain ◽  
Singularity Analysis ◽  
End Effector ◽  
Fixed Direction ◽  
Axis Parallel ◽  
Schönflies Motion ◽  
4 Degrees Of Freedom

A parallelogram-based 4 degrees-of-freedom parallel manipulator is presented in this paper. The manipulator can generate the so-called Schönflies motion that allows the end effector to translate in all directions and rotate around an axis parallel to a fixed direction. The theory of group of displacements is applied in the synthesis of this manipulator, which employs parallelograms in every limb. The planar parallelogram kinematic chain provides a high rotational capability and an improved stiffness to the manipulator. This paper shows the kinematic analysis of the manipulator, including the closed-form resolution of the forward and inverse position problems, the velocity, and the singularity analysis. Finally, a prototype of the manipulator, adding some considerations about its singularity-free design, and some technical applications in which the manipulator can be used are presented.

A symmetric parallel Schönflies-motion manipulator for pick-and-place operations

Robotica ◽  
2011 ◽  
Vol 29 (6) ◽  
pp. 853-862 ◽  
Author(s):  
O. Altuzarra ◽  
B. Şandru ◽  
Ch. Pinto ◽  
V. Petuya
Keyword(s):  
Group Theory ◽  
Kinematic Analysis ◽  
Parallel Manipulator ◽  
Degrees Of Freedom ◽  
Mechanical Device ◽  
End Effector ◽  
Pick And Place ◽  
Schönflies Motion ◽  
Motion Generator ◽  
Two Alternatives

SUMMARYThis paper presents a new symmetric parallel Schönflies-motion generator. The design is an evolution of a previous robot with linear inputs. The complete kinematic analysis of the 4-degree-of-freedom (dof) parallel manipulator is presented. The degrees of freedom are obtained from the Group Theory, the direct and inverse position problems are solved obtaining the manipulator's workspace, and the Jacobian analysis is presented. Then the isotropic configurations of the manipulator are discussed and the local dexterity map within the workspace is produced. Finally, two alternatives of a rotational mechanical device, which will increase the angular end-effector range, are proposed.

A Parallelogram-Based Parallel Manipulator For Scho¨nflies Motion

2006 ◽  
Author(s):  
Oscar Salgado ◽  
Oscar Altuzarra ◽  
Enrique Amezua ◽  
Alfonso Herna´ndez
Keyword(s):  
Closed Form ◽  
Kinematic Analysis ◽  
Parallel Manipulator ◽  
Degrees Of Freedom ◽  
Kinematic Chain ◽  
Singularity Analysis ◽  
End Effector ◽  
Fixed Direction ◽  
Axis Parallel

A parallelogram-based four degrees-of-freedom parallel manipulator is presented in this paper. The manipulator can generate the so-called Scho¨nflies motion, that allows the end-effector to translate in all directions and rotate around an axis parallel to a fixed direction. The Theory of Group of Displacements is applied in the synthesis of this manipulator, which employs parallelograms in every limb. The planar parallelogram kinematic chain provides a high rotational capability and a improved stiffness to the manipulator. The paper shows the kinematic analysis of the manipulator, including the closed-form resolution of the forward and inverse position problems, the velocity and the singularity analysis. Finally, a prototype of the manipulator and some technical applications in which the manipulator can be used are presented.

Type Synthesis of Variable Degrees-of-Freedom Parallel Manipulators With Both Planar and 3T1R Operation Modes

2012 ◽  
Author(s):  
Xianwen Kong
Keyword(s):  
Degrees Of Freedom ◽  
Operation Mode ◽  
Parallel Manipulators ◽  
Type Synthesis ◽  
Operation Modes ◽  
Moving Platform ◽  
Multiple Operation ◽  
Schönflies Motion

Parallel manipulators (PMs) with multiple operation modes are novel reconfigurable PMs which use less number of actuators and can be reconfigured without disassembly. Although several classes of PMs with multiple operation modes that have the same DOF (degrees-of-freedom) in all the operation modes have been proposed, only one class of variable-DOF PMs with multiple operation modes — PMs with multiple operation modes that do not have the same DOF in all the operation modes — have been proposed so far. This paper deals with the type synthesis of variable-DOF PMs with both planar and 3T1R (or Schönflies motion which has three translational DOF and 1 rotational DOF) operation modes. The axes of rotation of the moving platform in the planar operation mode are not parallel to the axes of rotation of the moving platform in the 3T1R operation mode. At first, an approach to the type synthesis of PMs with multiple operation modes is recalled. Based on the results on the type synthesis of planar PMs and 3T1R PMs, the types of variable-DOF PMs with both planar and 3T1R operation modes are then obtained. This work can be extended to the type synthesis of other classes of PMs with multiple operation modes.

scholarly journals Singularity Conditions of 3T1R Parallel Manipulators With Identical Limb Structures

2012 ◽  
Vol 4 (1) ◽  
Author(s):  
Semaan Amine ◽  
Mehdi Tale Masouleh ◽  
Stéphane Caro ◽  
Philippe Wenger ◽  
Clément Gosselin
Keyword(s):  
Parallel Manipulator ◽  
Jacobian Matrix ◽  
Parallel Manipulators ◽  
Singularity Analysis ◽  
Type Synthesis ◽  
Constraint Analysis ◽  
Fixed Direction ◽  
Geometric Singularity ◽  
Grassmann Geometry ◽  
Grassmann Cayley Algebra

This paper deals with the singularity analysis of parallel manipulators with identical limb structures performing Schönflies motions, namely, three independent translations and one rotation about an axis of fixed direction (3T1R). Eleven architectures obtained from a recent type synthesis of such manipulators are analyzed. The constraint analysis shows that these architectures are all overconstrained and share some common properties between the actuation and the constraint wrenches. The singularities of such manipulators are examined through the singularity analysis of the 4-RUU parallel manipulator. A wrench graph representing the constraint wrenches and the actuation forces of the manipulator is introduced to formulate its superbracket. Grassmann–Cayley Algebra is used to obtain geometric singularity conditions. Based on the concept of wrench graph, Grassmann geometry is used to show the rank deficiency of the Jacobian matrix for the singularity conditions. Finally, this paper shows the general aspect of the obtained singularity conditions and their validity for 3T1R parallel manipulators with identical limb structures.

Type Synthesis of Six-DOF Wrist-Partitioned Parallel Manipulators

2008 ◽  
Vol 130 (6) ◽  
Author(s):  
Xianwen Kong ◽  
Clément M. Gosselin
Keyword(s):  
Parallel Manipulator ◽  
General Structure ◽  
Parallel Manipulators ◽  
Singularity Analysis ◽  
Type Synthesis ◽  
Forward Displacement ◽  
Serial Manipulators ◽  
Six Dof ◽  
Moving Platform ◽  
Actuated Joints

A six-DOF wrist-partitioned parallel manipulator is a parallel manipulator in which three of the six actuated joints are used to control the position of a point on the moving platform while the other three are further used to control the orientation of the moving platform. Such parallel manipulators are, in fact, the parallel counterparts of the wrist-partitioned serial manipulators, which are widely used in industry. Unlike parallel manipulators of a general structure, a six-DOF wrist-partitioned parallel manipulator usually has simple kinematic characteristics such as its forward displacement analysis and singularity analysis are easy to solve. This paper deals with the type synthesis of six-DOF wrist-partitioned parallel manipulators. An approach is first proposed for the type synthesis of this class of parallel manipulators. Using the proposed approach, six-DOF wrist-partitioned parallel manipulators can be constructed from the types of three-DOF nonoverconstrained spherical parallel manipulators. A large number of six-DOF wrist-partitioned parallel manipulators are then obtained, and several types of practical relevance are also identified.

Design and Singularity Analysis of a 3-Translational-DOF In-Parallel Manipulator*

2002 ◽  
Vol 124 (3) ◽  
pp. 419-426 ◽  
Author(s):  
L. Romdhane ◽  
Z. Affi ◽  
M. Fayet
Keyword(s):  
Kinematic Analysis ◽  
Parallel Manipulator ◽  
Parallel Manipulators ◽  
Singularity Analysis ◽  
Orientation Error ◽  
Kinematic Chains ◽  
Prismatic Joints ◽  
Forward Kinematic ◽  
3D Solid ◽  
Novel Design

In this work, we shall present a novel design of a 3-translational-DOF in-parallel manipulator having 3 linear actuators. Three variable length legs constitute the actuators of this manipulator, whereas two other kinematic chains with passive joints are used to eliminate the three rotations of the platform with respect to the base. This design presents several advantages compared to other designs of similar 3-translational-dof parallel manipulators. First, the proposed design uses only revolute or spherical joints as passive joints and hence, it avoids problems that are inherent to the nature of prismatic joints when loaded in arbitrary way. Second, the actuators are chosen to be linear and to be located in the three legs since this design presents higher rigidity than other. In the second part of this paper, we addressed the problem of kinematic analysis of the proposed in-parallel manipulator. A mixed geometric and vector formulation is used to show that two solutions exist for the forward kinematic analysis. The problem of singularities is also investigated using the same method. In this work, we investigated the singularities of the active legs and the two types of singularity were identified: architectural singularities and configurational singularities. The singularity of the passive chains, used to restrict the motion of the platform to only three translations, is also investigated. In the last part of this paper, we built a 3D solid model of the platform and the amplitude of rotation due to the deformation of the different links under some realistic load was determined. This allowed us to estimate the “orientation error” of the platform due to external moments. Moreover, this analysis allowed us to compare the proposed design (over constrained) with a modified one (not over constrained). This comparison confirmed the conclusion that the over constraint design has a better rigidity.

Type Synthesis of Six-DOF Wrist-Partitioned Fully Parallel Manipulators

2007 ◽  
Author(s):  
Xianwen Kong ◽  
Cle´ment M. Gosselin
Keyword(s):  
Parallel Manipulator ◽  
General Structure ◽  
Parallel Manipulators ◽  
Singularity Analysis ◽  
Type Synthesis ◽  
Forward Displacement ◽  
Serial Manipulators ◽  
Six Dof ◽  
Moving Platform ◽  
Actuated Joints

A six-DOF wrist-partitioned fully parallel manipulator is a parallel manipulator in which three of the six actuated joints are used to control the position of a point on the moving platform while the other three are further used to control the orientation of the moving platform. Such parallel manipulators are in fact the parallel counterparts of the wrist-partitioned serial manipulators, which are widely used in industry. Unlike parallel manipulators of a general structure, a six-DOF wrist-partitioned fully parallel manipulator usually has simple kinematic characteristics such as its forward displacement analysis and singularity analysis are easy to solve. This paper deals with the type synthesis of six-DOF wrist-partitioned fully parallel manipulators. An approach is first proposed for the type synthesis of this class of parallel manipulators. Using the proposed approach, six-DOF wrist-partitioned fully parallel manipulators can be constructed from the types of three-DOF non-overconstrained spherical parallel manipulators. A large number of six-DOF wrist-partitioned fully parallel manipulators are then obtained, and several types of practical relevance are also identified.

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