Type Synthesis of Uncoupled 2T2R Parallel Manipulators

2012 ◽  
Author(s):  
Yanbin Zhang ◽  
Kwun-lon Ting
Keyword(s):  
Parallel Manipulator ◽  
Screw Theory ◽  
Control Design ◽  
Parallel Manipulators ◽  
Velocity Space ◽  
Type Synthesis ◽  
Systematic Method ◽  
Structure Synthesis ◽  
Hybrid Manipulator ◽  
Actuated Joints

This paper presents a simple and systematic method for type synthesis of four-degree-of-freedom uncoupled parallel manipulators with two-translational and two-rotational (2T2R) motion components. Based on the concept of hybrid manipulator, one uncoupled 2T2R hybrid manipulator, which is composed of one full-isotropic planar 2T1R parallel manipulator and one revolute joint in serial assembly, is designed first. Then the structure synthesis of the fourth leg of 2T2R parallel manipulator is performed in terms of the reciprocal screw theory. Finally, the type synthesis of uncoupled 2T2R parallel manipulators is realized by combining the uncoupled 2T2R hybrid manipulator and one of the synthesized fourth legs. The Jacobian of the uncoupled 2T2R parallel manipulator is a 4×4 diagonal matrix. Therefore, there exists a one-to-one correspondence between the input velocity space of the actuated joints and the output velocity space of the moving platform. Moreover, both the control design and the path planning of these proposed manipulators are very simple.

Structure Synthesis of 3-RRS Type Spatial Compliant Parallel Manipulator

2010 ◽  
Vol 44-47 ◽  
pp. 1375-1379
Author(s):  
Da Chang Zhu ◽  
Li Meng ◽  
Tao Jiang
Keyword(s):  
Parallel Manipulator ◽  
Compliant Mechanisms ◽  
Screw Theory ◽  
Weight Ratio ◽  
Parallel Manipulators ◽  
Robot System ◽  
New Approach ◽  
Structure Synthesis ◽  
Rigid Joints ◽  
Type 3

Parallel manipulators has been extensively studied by virtues or its high force-to-weight ratio and widely spread applications such as vehicle or flight simulator, a machine tool and the end effector of robot system. However, as each limb includes several rigid joints, assembling error is demanded strictly, especially in precision measurement and micro-electronics. On the other hand, compliant mechanisms take advantage of recoverable deformation to transfer or transform motion, force, or energy and the benefits of compliant mechanisms mainly come from the elimination of traditional rigid joints, but the traditional displacement method reduce the stiffness of spatial compliant parallel manipulators. In this paper, a new approach of structure synthesis of 3-DoF rotational compliant parallel manipulators is proposed. Based on screw theory, the structures of RRS type 3-DoF rotational spatial compliant parallel manipulator are developed. Experiments via ANSYS are conducted to give some validation of the theoretical analysis.

Type Synthesis of 3-DOF Spherical Parallel Manipulators Based on Screw Theory1

2004 ◽  
Vol 126 (1) ◽  
pp. 101-108 ◽  
Author(s):  
Xianwen Kong ◽  
Cle´ment M. Gosselin
Keyword(s):  
Parallel Manipulator ◽  
Screw Theory ◽  
General Procedure ◽  
Kinematic Chain ◽  
Parallel Manipulators ◽  
Type Synthesis ◽  
Validity Condition ◽  
First Time ◽  
Spherical Parallel Manipulator ◽  
Selection Of

A spherical parallel manipulator (SPM) refers to a 3-DOF (degree-of-freedom) parallel manipulator generating 3-DOF spherical motion. A method is proposed for the type synthesis of SPMs based on screw theory. The wrench systems of a spherical parallel kinematic chain (SPKC) and its legs are first analyzed. A general procedure is then proposed for the type synthesis of SPMs. The type synthesis of legs for SPKCs, the type synthesis of SPKCs, as well as the selection of inputs of SPMs are dealt with in sequence. An input validity condition of SPMs is proposed. SPKCs with and without inactive joints are synthesized. The number of overconstraints of each SPKC is also given. The phenomenon of dependent joint groups in an SPKC is revealed for the first time.

Type Synthesis of Symmertrical Non-Overconstrained 3-DOF Translational Parallel Manipulators Based on Srew Theory

2011 ◽  
Vol 308-310 ◽  
pp. 2135-2138
Author(s):  
Yong Gang Huang ◽  
Li Du ◽  
Ya Hua Chen ◽  
Jun Feng
Keyword(s):  
Screw Theory ◽  
Parallel Manipulators ◽  
Type Synthesis ◽  
Systematic Method ◽  
Serial Chains

Based on screw theory,a systematic method is proposed to synthesis symmertrical non-overconstrained 3-DOF translational parallel manipulators(TPMs).Firstly,the configuration conditions of non-overconstrained TPMs are analysis.The generation of symmertrical non-overconstrained TPMs is reduced to design the structure of serial chains with one infinite pitch wrench,and to combine the same serial chains inparallel.Finally,making sure that, the union of the wrench for the same serial chains in each combination constitutes a three infinite pitch wrench system.we get all the 3-legged symmertrical non-overconstrained TPMs.

Synthesis of 2T1R Decoupled Parallel Manipulators

2011 ◽  
Vol 308-310 ◽  
pp. 2025-2030 ◽  
Author(s):  
Wen Juan Lu ◽  
Li Jie Zhang ◽  
Da Xing Zeng ◽  
Ruo Song Wang
Keyword(s):  
Screw Theory ◽  
Control Design ◽  
Parallel Manipulators ◽  
Parallel Mechanisms ◽  
Type Synthesis ◽  
Precision Control ◽  
Kinematic Chains ◽  
Step Procedure ◽  
Nonlinear Relation ◽  
Three Degree Of Freedom

For the general parallel mechanisms(PMS), since the coupling between kinematic chains, the nonlinear relation between the input and output is presented, which have led to difficulty in the trajectory planning and precision control. Design of motion decoupled parallel mechanisms(DPMS) has become a good new topic in this area and has captured researcher's attention. In this work, the approach to a synthesis of three degree-of-freedom(3-DOF) DPMS is considered based on screw theory and motion synthesis ideas. Criterions for type synthesis of the branches for DPMS is established according to the twist screw system of the limbs, which assures the decoupling in each limb. Then a six-step procedure is presented for the type synthesis of 2T1R decoupled mechanisms.

scholarly journals Type synthesis of uncoupled translational parallel manipulators based on actuation wrench screw theory

2018 ◽  
Vol 10 (1) ◽  
pp. 168781401774843
Author(s):  
Yanbin Zhang ◽  
Yifu Zhao ◽  
Xianling Jing ◽  
Xiangpan Li
Keyword(s):  
Degrees Of Freedom ◽  
Screw Theory ◽  
Full Rank ◽  
Basic Structure ◽  
Parallel Manipulators ◽  
Rotational Mobility ◽  
Type Synthesis ◽  
Structure Synthesis ◽  
Moving Platform ◽  
Set Up

In this article, a new methodology for type synthesis of uncoupled translational parallel manipulators with 3-degrees of freedom is proposed based on actuation wrench screw theory. Mapping matrix between outputs of the moving platform and the inputs of the actuators for uncoupled translational parallel manipulators is derived. The forms of both the actuated twist screws and the actuation wrench screws of the limbs are determined by means of the condition that the Jacobian is a diagonal matrix with full rank. The steps used to confirm the non-actuated screws of the limbs are also established. Then, procedures for structure synthesis of the limbs are set up and all possible basic structure limbs are enumerated. Some new uncoupled translational parallel manipulators are synthesized by selecting three limbs connecting the platform to the base and two examples are given. The approach proposed is applicable to the type synthesis of uncoupled parallel manipulators with rotational mobility as well.

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.

Jacobian-based stiffness analysis method for parallel manipulators with non-redundant legs

2015 ◽  
Vol 230 (3) ◽  
pp. 341-352 ◽  
Author(s):  
Antonius GL Hoevenaars ◽  
Patrice Lambert ◽  
Just L Herder
Keyword(s):  
Parallel Manipulator ◽  
Screw Theory ◽  
Parallel Manipulators ◽  
Structural Elements ◽  
Analysis Method ◽  
End Effector ◽  
Stiffness Analysis ◽  
Compliant Joints ◽  
Lower Mobility ◽  
Actuated Joints

Stiffness is an important element in the model of a parallel manipulator. A complete stiffness analysis includes the contributions of joints as well as structural elements. Parallel manipulators potentially include both actuated joints, passive compliant joints, and zero stiffness joints, while a leg may impose constraints on the end-effector in the case of lower mobility parallel manipulators. Additionally, parallel manipulators are often designed to interact with an environment, which means that an external wrench may be applied to the end-effector. This paper presents a Jacobian-based stiffness analysis method, based on screw theory, that effectively considers all above aspects and which also applies to parallel manipulators with non-redundant legs.

Type Synthesis of 3-DOF Translational Parallel Manipulators Based on Screw Theory

2004 ◽  
Vol 126 (1) ◽  
pp. 83-92 ◽  
Author(s):  
Xianwen Kong ◽  
Cle´ment M. Gosselin
Keyword(s):  
Screw Theory ◽  
General Procedure ◽  
Linear Equations ◽  
Kinematic Chain ◽  
Parallel Manipulators ◽  
Type Synthesis ◽  
Displacement Analysis ◽  
Kinematic Chains ◽  
Small Joint ◽  
Actuated Joints

A method is proposed for the type synthesis of 3-DOF (degree-of-freedom) translational parallel manipulators (TPMs) based on screw theory. The wrench systems of a translational parallel kinematic chain (TPKC) and its legs are first analyzed. A general procedure is then proposed for the type synthesis of TPMs. The type synthesis of legs for TPKCs, the type synthesis of TPKCs as well as the selection of actuated joints of TPMs are dealt with in sequence. An approach to derive the full-cycle mobility conditions for legs for TPKCs is proposed based on screw theory and the displacement analysis of serial kinematic chains undergoing small joint motions. In addition to the TPKCs proposed in the literature, TPKCs with inactive joints are synthesized. The phenomenon of dependent joint groups in a TPKC is revealed systematically. The validity condition of actuated joints of TPMs is also proposed. Finally, linear TPMs, which are TPMs whose forward displacement analysis can be performed by solving a set of linear equations, are also revealed.

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.

Type Synthesis of 3-DOF PPR Parallel Manipulators Based on Screw Theory and the Concept of Virtual Chain

2004 ◽  
Author(s):  
Xianwen Kong ◽  
Cle´ment M. Gosselin
Keyword(s):  
Screw Theory ◽  
Parallel Manipulators ◽  
Type Synthesis ◽  
Motion Patterns ◽  
Kinematic Chains ◽  
Serial Robots ◽  
Prismatic Joints ◽  
Parallel Kinematic ◽  
Actuated Joints ◽  
Selection Of

PPR-PMs (parallel manipulators) are the parallel counterparts of the 3-DOF PPR serial robots, which are composed of two P (prismatic) joints and one R (revolute) joint. For a PPR-PM, the moving platform can rotate arbitrarily about an axis undergoing a planar translation. This paper deals with the type synthesis of 3-DOF PPR-PMs. At first, virtual chains are introduced to represent the motion patterns of 3-DOF motions and relevant results from screw theory are recalled. A method is then proposed for the type synthesis of 3-DOF PPR-PMs. Using the proposed approach, the type synthesis of 3-DOF PPR-PMs is performed in three steps, namely, the type synthesis of legs for PPR-PKCs (parallel kinematic chains), the type synthesis of PPR-PKCs, and the selection of actuated joints of PPR-PMs. The three steps are dealt with in detail consequently. The characteristics of the proposed approach is that the type synthesis of legs for PPR-PKCs is reduced to the type synthesis of 3-DOF overconstrained single-loop kinematic chains and thus easy to perform. In addition to all the 3-DOF PPR-PKCs and 3-DOF PPR-PMs proposed in the literature, a number of new 3-DOF PPR-PKCs and 3-DOF PPR-PMs are identified. It is also found that there are no PPR-PMs with identical types of legs.

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