Type Synthesis of Parallel Mechanisms With Multiple Operation Modes

2006 ◽  
Vol 129 (6) ◽  
pp. 595-601 ◽  
Author(s):  
Xianwen Kong ◽  
Clément M. Gosselin ◽  
Pierre-Luc Richard
Keyword(s):  
Parallel Mechanism ◽  
Degrees Of Freedom ◽  
Translational Motion ◽  
Parallel Mechanisms ◽  
Motion Pattern ◽  
Type Synthesis ◽  
Motion Patterns ◽  
Operation Modes ◽  
Multiple Operation ◽  
Spherical Motion

There are usually several motion patterns having the same degrees of freedom (DOF). For example, planar motion, spherical motion, and spatial translation are motion patterns with 3 DOF. An f-DOF parallel mechanism with multiple operation modes is a parallel mechanism that can generate different motion patterns with f DOF. Up to now, no method has been proposed for the type synthesis of parallel mechanisms with multiple operation modes. This paper presents a general method for the type synthesis of parallel mechanisms with multiple operation modes. Using the proposed approach, 3-DOF parallel mechanisms with both spherical and translational modes, i.e., parallel mechanism generating both a spherical motion pattern and a spatial translational motion pattern, are generated systematically. A large number of parallel mechanisms with both spherical and translational modes are obtained.

Type Synthesis of Parallel Mechanisms With Multiple Operation Modes

2006 ◽  
Author(s):  
Xianwen Kong ◽  
Cle´ment M. Gosselin ◽  
Pierre-Luc Richard
Keyword(s):  
Parallel Mechanism ◽  
Translational Motion ◽  
Parallel Mechanisms ◽  
Motion Pattern ◽  
Type Synthesis ◽  
Motion Patterns ◽  
Operation Modes ◽  
Multiple Operation ◽  
Spherical Motion ◽  
General Method

There are usually several motion patterns having the same DOF (degree of freedom). For example, planar motion, spherical motion, and spatial translation are motion patterns with 3-DOF. An f-DOF parallel mechanism with multiple operation modes is a parallel mechanism that can generate different motion patterns with f DOF. Up to now, no method has been proposed for the type synthesis of parallel mechanisms with multiple operation modes. This paper presents a general method for the type synthesis of parallel mechanisms with multiple operation modes. Using the proposed approach, 3-DOF parallel mechanisms with both spherical and translational modes, i.e., parallel mechanisms generating both the spherical motion pattern and the spatial translational motion pattern, are generated systematically. A large number of parallel mechanisms with both spherical and translational modes are obtained.

Type Synthesis of Two-Degrees-of-Freedom 3-4R Parallel Mechanisms With Both Spherical Translation Mode and Sphere-on-Sphere Rolling Mode

2015 ◽  
Vol 7 (4) ◽  
Author(s):  
Xianwen Kong ◽  
Jingjun Yu
Keyword(s):  
Degrees Of Freedom ◽  
Parallel Manipulators ◽  
Parallel Mechanisms ◽  
Type Synthesis ◽  
Operation Modes ◽  
The Common ◽  
Moving Platform ◽  
Multiple Operation ◽  
Overconstrained Mechanisms ◽  
Rolling Mode

Parallel manipulators (PMs) with multiple operation modes are novel reconfigurable PMs, which use less number of actuators and can be reconfigured without disassembly. This paper deals with the type synthesis of 2-DOF (degrees-of-freedom) PMs with both spherical translation mode and sphere-on-sphere rolling mode. A spherical translation is the 2-DOF spatial translation under which the trajectory of any point on the moving link is a sphere. A sphere-on-sphere rolling refers to the rolling of a sphere without slipping and spinning on another sphere of the same diameter. At first, a 2-DOF 3-4R overconstrained PM is proposed based on an existing 5-DOF US equivalent PM. From this 2-DOF PM, we further obtain a 3-4R PM for sphere-on-sphere rolling and a 3-4R PM for spherical translation. By finding the common conditions for the 2-DOF 3-4R PM for spherical translation and 2-DOF 3-4R PM for sphere-on-sphere rolling, the types of 2-DOF 3-4R PMs with both spherical translation mode and sphere-on-sphere rolling mode are then obtained. The 2-DOF 3-4R PMs with both spherical translation mode and sphere-on-sphere rolling mode fall into two classes. In one class of PMs with both spherical translation mode and sphere-on-sphere rolling mode, the moving platform has four instantaneous DOF in a transition configuration. In another class of PMs with both spherical translation mode and sphere-on-sphere rolling mode, the moving platform has at most three instantaneous DOF in a transition configuration. This work enriches the types of PMs with multiple operation modes and overconstrained mechanisms.

Type synthesis of 2R2T parallel mechanisms based on motion equivalent chain method

2014 ◽  
Vol 228 (17) ◽  
pp. 3209-3217 ◽  
Author(s):  
Wei Ye ◽  
Yuefa Fang ◽  
Sheng Guo ◽  
Haibo Qu
Keyword(s):  
Parallel Mechanism ◽  
Screw Theory ◽  
Parallel Mechanisms ◽  
Motion Pattern ◽  
Type Synthesis ◽  
Constraint Force ◽  
Single Loop ◽  
Loop Chain ◽  
Serial Chains

In this paper, the motion equivalent chain method is proposed and then applied to the type synthesis of a class of 2R2T parallel mechanism. The equivalent serial chains are synthesized for a specific 2R2T motion pattern based on screw theory. Feasible limb structures that provide a constraint couple and a constraint force are enumerated according to the reciprocity of the twist and wrench systems. Several motion equivalent single loop chains are constructed with the equivalent serial chains. Using motion equivalent single loop chains to replace the equivalent serial chains, a class of 2R2T parallel mechanisms is obtained based on the foundation of motion equivalent single loop chain structures.

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.

Investigations on the principle of full decoupling and type synthesis of 2R1T and 2R parallel mechanisms

2019 ◽  
Vol 43 (2) ◽  
pp. 263-271 ◽  
Author(s):  
Yundou Xu ◽  
Bei Wang ◽  
Zhifeng Wang ◽  
Yun Zhao ◽  
Wenlan Liu ◽  
...  
Keyword(s):  
Parallel Mechanism ◽  
Degrees Of Freedom ◽  
Parallel Mechanisms ◽  
Type Synthesis ◽  
Rotational Degrees Of Freedom ◽  
The Relationship

Based on the relationship between constraint wrenches and rotational axes, the principle of full decoupling of two rotational degrees of freedom (DOFs) for a two-rotation and one-translation (2R1T) parallel mechanism and two-rotation (2R) parallel mechanism with three supporting branches is systematically analyzed. Two conditions for full decoupling of two rotational DOFs of such mechanisms are obtained. The relationship between the two rotational axes of the parallel mechanisms is classified into two cases: intersecting and different. Next, based on the two conditions, type synthesis of the 2R1T and 2R parallel mechanisms with fully decoupled two rotational DOFs is carried out. A series of novel 2R1T and 2R parallel mechanisms with fully decoupled two rotational DOFs are obtained, such as RPU–UPR–RPR. Several of these mechanisms contain only eight single-DOF passive joints, one fewer than in existing mechanisms of this type, and thus have broad applications.

Type Synthesis of 2-DOF 3-4R Parallel Mechanisms With Both Spatial Parallelogram Translational Mode and Equal-Diameter Spherical Rotation Mode

2014 ◽  
Author(s):  
Xianwen Kong ◽  
Jingjun Yu
Keyword(s):  
Parallel Manipulators ◽  
Parallel Mechanisms ◽  
Type Synthesis ◽  
Rotation Mode ◽  
Operation Modes ◽  
Translational Mode ◽  
The Common ◽  
Multiple Operation ◽  
Overconstrained Mechanisms

Parallel manipulators (PMs) with multiple operation modes are novel reconfigurable PMs which use less number of actuators and can be reconfigured without disassembly. This paper deals with the type synthesis of 2-DOF PMs with both spatial parallelogram translational mode and equal-diameter spherical rotation mode. At first, a 2-DOF 3-4R overconstrained PM is proposed based on a 5-DOF US equivalent PM proposed in the literature. From this 2-DOF PM, we further obtain a 3-4R PM for equal-diameter spherical rotation and a 3-4R PM for spatial parallelogram translation. By finding the common conditions for the 2-DOF 3-4R PM for spatial parallelogram translation and 2-DOF 3-4R PM for equal-diameter spherical rotation, the types of 2-DOF 3-4R PMs with both spatial parallelogram translational mode and equal-diameter spherical rotation mode are then obtained. This work enriches the types of PMs with multiple operation modes and overconstrained mechanisms.

Lie Group Based Type Synthesis Using Transformation Configuration Space for Reconfigurable Parallel Mechanisms With Bifurcation Between Spherical Motion and Planar Motion

2019 ◽  
Vol 142 (6) ◽  
Author(s):  
Jun Wei ◽  
Jian S. Dai
Keyword(s):  
Configuration Space ◽  
Parallel Mechanism ◽  
Identity Element ◽  
Parallel Mechanisms ◽  
Type Synthesis ◽  
Motion Representation ◽  
Kinematic Chains ◽  
Common Intersection ◽  
The Common ◽  
Spherical Motion

Abstract This paper investigates novel reconfigurable parallel mechanisms with bifurcation between planar subgroup SE(2) and rotation subgroup SO(3) based on a transformation configuration space. Having recollected necessary theoretical fundamentals with regard to compositional submanifolds and kinematic bonds, the motion representation of the platform of reconfigurable parallel mechanisms are investigated. The transformation configuration space of a reconfigurable parallel mechanism with motion branches is proposed with respect to the fact that the intersection of Lie subgroups or submanifolds is the identity element or a non-identity element. The switch conditions of the transformation configuration space are discussed, leading to establishment of a theoretical foundation for realizing a switch of motion branches. The switch principle of reconfigurable parallel mechanisms is further investigated with respect to the common motion between SE(2) parallel-mechanism motion generators and SO(3) parallel-mechanism motion generators. Under this principle, the subchains with common motion generators are synthesized and divided into two types of generators. The first type of generators generates kinematic chains with a common intersection of three joint axes, and the second type of generators generates a common intersection of two joint axes. Following this, two types of reconfigurable parallel mechanisms with three identical subchains are synthesized, resulting in 11 varieties in which platforms can be switched between SE(2) and SO(3) after passing through the singularity configuration space.

Type Synthesis of 3-RSR Equivalent 2R1T Parallel Mechanisms

2018 ◽  
Author(s):  
Ziming Chen ◽  
Yanwen Li ◽  
Zhen Huang ◽  
Xianwen Kong
Keyword(s):  
Degrees Of Freedom ◽  
Screw Theory ◽  
Parallel Mechanisms ◽  
Type Synthesis ◽  
Motion Patterns ◽  
Continuous Rotations ◽  
Motion Characteristics

Parallel mechanisms (PMs) with two rotational and one translational (2R1T) degrees of freedom (DOFs) have attracted much attention these years. The 2R1T PMs can be divided into various categories due to different motion patterns, such as the UP equivalent PMs, the RPR equivalent PMs, the PU equivalent PMs and the 3-PPS equivalent PMs. In this paper, the 2R1T PMs have the same motion characteristics with the 3-RSR PM are studied and synthesized. This kind of PMs can be called as 3-RSR equivalent 2R1T PMs. The 3-RSR equivalent 2R1T PMs can realize both continuous rotations about fixed axes and continuous translation along fixed directions. The constraint and motion characteristics of the 3-RSR equivalent 2R1T PMs are analyzed. The design of the branches for the 3-RSR equivalent 2R1T PMs is dealt with using the screw theory and the subchains. A group of novel 3-RSR equivalent 2R1T PMs are obtained.

scholarly journals Type Synthesis of 1T2R Parallel Mechanisms Using Structure Coupling-Reducing Method

2019 ◽  
Vol 32 (1) ◽  
Author(s):  
Haitao Liu ◽  
Ke Xu ◽  
Huiping Shen ◽  
Xianlei Shan ◽  
Tingli Yang
Keyword(s):  
Explicit Form ◽  
Parallel Mechanism ◽  
Analytic Solutions ◽  
Forward Kinematics ◽  
Parallel Mechanisms ◽  
Type Synthesis ◽  
Real Time Control ◽  
Time Control ◽  
Topological Characteristics ◽  
Zero Coupling

Abstract Direct kinematics with analytic solutions is critical to the real-time control of parallel mechanisms. Therefore, the type synthesis of a mechanism having explicit form of forward kinematics has become a topic of interest. Based on this purpose, this paper deals with the type synthesis of 1T2R parallel mechanisms by investigating the topological structure coupling-reducing of the 3UPS&UP parallel mechanism. With the aid of the theory of mechanism topology, the analysis of the topological characteristics of the 3UPS&UP parallel mechanism is presented, which shows that there are highly coupled motions and constraints amongst the limbs of the mechanism. Three methods for structure coupling-reducing of the 3UPS&UP parallel mechanism are proposed, resulting in eight new types of 1T2R parallel mechanisms with one or zero coupling degree. One obtained parallel mechanism is taken as an example to demonstrate that a mechanism with zero coupling degree has an explicit form for forward kinematics. The process of type synthesis is in the order of permutation and combination; therefore, there are no omissions. This method is also applicable to other configurations, and novel topological structures having simple forward kinematics can be obtained from an original mechanism via this method.

scholarly journals Design of Self-Reconfigurable Multiarm Robot Mechanism Based on Deployable Kinematic Chains

2020 ◽  
Vol 33 (1) ◽  
Author(s):  
Fu-Qun Zhao ◽  
Sheng Guo ◽  
Hai-Jun Su ◽  
Hai-Bo Qu ◽  
Ya-Qiong Chen
Keyword(s):  
Parallel Mechanism ◽  
Parallel Mechanisms ◽  
Kinematic Chains ◽  
Assembly Method ◽  
Operation Modes ◽  
Object Based ◽  
Switch Operation ◽  
Storage Area ◽  
Mechanism Theory

Abstract As the structures of multiarm robots are serially arranged, the packaging and transportation of these robots are often inconvenient. The ability of these robots to operate objects must also be improved. Addressing this issue, this paper presents a type of multiarm robot that can be adequately folded into a designed area. The robot can achieve different operation modes by combining different arms and objects. First, deployable kinematic chains (DKCs) are designed, which can be folded into a designated area and be used as an arm structure in the multiarm robot mechanism. The strategy of a platform for storing DKCs is proposed. Based on the restrictions in the storage area and the characteristics of parallel mechanisms, a class of DKCs, called base assembly library, is obtained. Subsequently, an assembly method for the synthesis of the multiarm robot mechanism is proposed, which can be formed by the connection of a multiarm robot mechanism with an operation object based on a parallel mechanism structure. The formed parallel mechanism can achieve a reconfigurable characteristic when different DKCs connect to the operation object. Using this method, two types of multiarm robot mechanisms with four DKCs that can switch operation modes to perform different tasks through autonomous combination and release operation is proposed. The obtained mechanisms have observable advantages when compared with the traditional mechanisms, including optimizing the occupied volume during transportation and using parallel mechanism theory to analyze the switching of operation modes.

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