Yuefa Fang

Yuefa Fang
Beijing Jiaotong University | NJTU · Department of Mechanical Engineering

PhD

About

118
Publications
25,432
Reads
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2,229
Citations
Citations since 2016
27 Research Items
1259 Citations
2016201720182019202020212022050100150200
2016201720182019202020212022050100150200
2016201720182019202020212022050100150200
2016201720182019202020212022050100150200
Additional affiliations
June 1996 - present
Beijing Jiaotong University
Position
  • Professor (Full)

Publications

Publications (118)
Article
The complex structures, small workspaces and complex control systems of traditional parallel mechanisms are the largest hurdles to using them as leg mechanisms in walking robots. This paper synthesizes a family of novel 3-degrees-of-freedom (DOF) parallel leg mechanisms (PLMs) that have the potential to avoid these drawbacks. The novel parallel leg...
Article
Generalized parallel mechanisms with a configurable moving platform have become popular in the research field of parallel mechanism. This type of gripper mechanism can be applied to grasp large or heavy objects in different environments that are dangerous and complex for humans. This study proposes a family of novel (5 + 1) degrees of freedom (thre...
Article
This paper systematically develops the type synthesis of single-loop parallel mechanisms (PMs) with three translations (T) along three independent directions and one rotation (R) around one fixed direction (3T1R-PMs). Each limb is driven by a multi-degree of freedom (DOF) drive system, and the output link can generate large rotational angle. Based...
Preprint
Full-text available
Due to the complex structures of multi-limbed parallel robots, conventional parallel robots generally have limited workspace, complex kinematics, and complex dynamics, which increases the application difficulty of parallel robot in industrial engineering. To solve the above problems, this paper proposes a single-loop Schönflies motion parallel robo...
Article
Limited rotational angles caused by the interference between the moving platform and kinematic chains of parallel mechanisms (PMs) has always been an issue. Hence a class of two-rotation and one-translation (2R1T) generalized parallel mechanisms (GPMs) with a high rotational capability, where the end effector is placed on the joint to avoid the pro...
Article
Inspired by fewer-limb multi-degree-of-freedom (DOF) parallel mechanisms (PMs), a systematic method that synthesizes multi-DOF drive systems is presented based on Lie group theory. Multi-DOF drive systems can generate more DOFs motion than a pure rotation or a pure translation. The benefit of such multi-DOF drive systems is that all motors are moun...
Article
The dexterous hands with high dexterity, high carrying capability, high precision and high task adaptability (multipurpose) are demanded in industry. This paper focuses on designing dexterous hands based on the parallel finger structures to improve above performances. Based on the motion property of human finger, the required motion types of the de...
Article
This paper presents a class of novel 3-degree-of-freedom (DOF) single-loop parallel leg mechanisms for walking robots. An approach for constructing the 3-DOF single-loop parallel leg mechanism is proposed. The single-loop parallel leg mechanism is composed of a serial limb with two actuated joints and a serial limb with one actuated joint, where tw...
Article
Full-text available
The parallel spindle heads with high rotational capability are demanded in the area of multi-axis machine tools and 3D printers. This paper focuses on designing a class of 2R1T (R: Rotation; T: Translation) parallel spindle heads and the corresponding collaborative 5-axis manipulators with 2-dimension (2D) large rotational angles. In order to const...
Article
As an important end-effector of robots, dexterous hand's relatively low carrying capacity, small workspace and poor task adaptability become the key factors restricting their wide application. To overcome above shortcomings of dexterous hands, a novel Lie group based synthesis method that evolve the 3-[P][S] parallel mechanisms(PMs) into dexterous...
Article
Compared with conventional parallel manipulators with serial kinematic chains supporting a nonflexible platform, generalized parallel mechanisms may be further constrained by interconnected coupling sub-chains or configurable platforms. The additional coupling sub-chains and configurable platforms have the potential advantages of improving overall...
Conference Paper
A conventional parallel manipulator consists of a moving platform, a fixed base platform, as well as several serial chains that connect the two platforms. This paper presents a novel five degree-of-freedom (DOF) hybrid manipulator such that its base platform itself is movable and thus reconfigurable. This hybrid structure greatly expands the worksp...
Article
Full-text available
Most of researchers focused on traditional six degrees of freedom (DOF) Stewart flight simulator, which can not be adaptive in fighter-aircraft flight simulator. A three rotational DOF flight simulator of fighter-aircraft based on double parallel manipulator and hybrid structure is presented. The flight simulator is composed of two identical 3-RRS...
Article
Full-text available
Most parallel mechanisms (PMs) encountered today have a common disadvantage, i.e., their low rotational capability. In order to develop PMs with high rotational capability, a family of novel manipulators with one or two dimensional rotations is proposed. The planar one-rotational one-translational (1R1T) and one-rotational two-translational (1R2T)...
Article
Full-text available
In order to solve the problem of the honeycombs perfusion in the thermal protection system of the spacecraft, this paper presents a novel parallel perfusion manipulator with one translational and two rotational (1T2R) degrees of freedom (DOFs), which can be used to construct a 5-DOF hybrid perfusion system for the perfusion of the honeycombs. The p...
Article
The conventional parallel mechanism (CPM) is characterized by connecting serial kinematic limbs or chains to the moving platform or linkage. The mobility and motion pattern of the CPM may be further constrained by adding a coupling sub-chain to serial kinematic chains. That will result in a new class of mechanisms called generalized parallel mechan...
Article
Full-text available
This paper presents a novel parallel manipulator with one translational and two rotational (1T2R) degrees of freedom that can be employed to form a five-degree-of-freedom hybrid kinematic machine tool for large heterogeneous complex structural component machining in aerospace field. Compared with serial or parallel machine, hybrid machine has the m...
Article
With the deepening and refinement of research, the traditional parallel mechanisms (PMs) have become increasingly hard to satisfy the demands of high rotational performance, decoupled motions, or some other specific motion properties. This paper focuses on the synthesis of a class of generalized parallel mechanisms (GPMs), which are capable of pres...
Article
A conventional parallel manipulator uses serial kinematic chains or the legs to support a single moving platform. The movement of the platform may be further constrained by adding interconnections among its legs to form the so-called coupling sub-chains. The introduction of coupling sub-chains to the kinematic structures of parallel manipulators, w...
Article
This article focuses on the synthesis and analysis of a class of novel 2T2R (T denotes Translation and R denotes Rotation) and 3T2R parallel mechanisms (PMs) with large decoupled output rotational angles. Two articulated moving platforms (AMPs) composed by revolute joints are proposed. A common parallelogram and an evolution parallelogram which are...
Article
This paper presents a planar five-bar metamorphic linkage which has five phases resulting from locking of motors. Reconfigurable limbs are constructed by integrating the five-bar metamorphic linage as sub-chains. The branch transition of metamorphic linkage is analyzed. By adding appropriate joints to the planer five-bar metamorphic linkage, reconf...
Article
This paper proposes a class of closed-loop metamorphic linkages, which has different phases resulting from links annexing or locking of motors. Reconfigurable limbs are obtained by assembling these metamorphic linkages with kinematic chains. The potential metamorphic linkages are presented and the working phase transformation of the metamorphic lin...
Article
Conventional overconstrained parallel manipulators have been widely studied both in industry and academia, however the structural synthesis of hybrid mechanisms with additional constraints is seldom studied, especially for the four degrees of freedom (DOF) hybrid mechanisms. In order to develop a manipulator with additional constraints, a class of...
Article
Full-text available
This paper presents a novel multi-diamond kinematotropic chain that has various motion branches. The motion allowed by the chain in different branches is identified based on Lie group theory. A planar reconfigurable limb is obtained by adding a prismatic joint to the output link of the multi-diamond kinematotropic chain, leading to the construction...
Conference Paper
In this paper, we focus our attention on a parallel mechanism with four identical limbs and two moving platforms that are connected by a prismatic joint. Firstly, the degrees of freedom analysis of the mechanism is conducted based on the displacement group theory. Both the two moving platforms have the ability to perform two rotational and two tran...
Article
Large rotational angles about two axes for parallel mechanisms (PMs) with two rotational and three translational (2R3T) degrees of freedom (DOFs) or two rotational and two translational (2R2T) DOFs are demanded in some industries, such as parallel machine tools and multi-axis 3D printing. To address the problem, this paper focuses on the structural...
Article
The motion characteristic of a discontinuously movable mechanism with special link length condition is analyzed. In different configurations, the discontinuously movable mechanism has one rotational and one translational motions, one translational motion, one rotational motion, respectively. Reconfigurable hybrid limbs are obtained by integrating t...
Article
Dimensional synthesis is one of the most difficult issues in the field of parallel robots with actuation redundancy. To deal with the optimal design of a redundantly actuated parallel robot used for ankle rehabilitation, a methodology of dimensional synthesis based on multi-objective optimization is presented. First, the dimensional synthesis of th...
Article
Full-text available
The analysis of degrees of freedom(DOF) of a moving platform is the fundamental problem in kinematics of parallel mechanism. However, many problems should be considered to correctly perform the DOF calculation by using the traditional DOF criterion, and it is difficult to find a DOF criterion suitable for all kinds of mechanisms. A rule that can be...
Article
The wind turbine airfoil aerodynamic and noise performace were considered as optimization design target at the same time, then a design method was established for multi operating points and targets. Parametric model of airfoil contour was constructed by using Bezier curves, and the general equtions for control points coordinate were deduced accordi...
Article
Full-text available
In this paper, a new method is proposed for the structural synthesis of a class of redundantly-actuated parallel wrists (RaPWs) with three rotational degrees of freedom of the moving platform and symmetrical structures based on screw theory. First, the new procedure for structural synthesis of RaPWs with closed-loop actuated unit is proposed and th...
Article
This paper describes the design, kinematics, and workspace analysis of 3R2T and 3R3T parallel mechanisms (PMs) with large rotational angles about three axes. Since the design of PMs with high rotational capability is still a challenge, we propose the use of a new nonrigid (or articulated) moving platform with passive joints in order to reduce the i...
Article
The paper proposes a novel type of flight simulator with 6-RRS spherical parallel manipulator. It has 3 degrees of freedom (DoF), 6 actuators and 3 redundant actuators. Two totally same spherical parallel manipulators consist of the flight simulator, it still has one fixed base in general and one motive base, the whole motive volume is served as th...
Article
Full-text available
This paper aims at designing a pure translational parallel mechanism constructed by UPU (universal-prismatic-universal joint) kinematic limbs. First, the typical problem of unexpected rotations is pointed out from analyzing the typical 3-UPU parallel mechanism, and the reason for unexpected rotations of parallel mechanism constructed by UPU kinemat...
Article
Full-text available
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 t...
Article
In this paper, we propose a novel biped walking robot on the basis of a spatial eight-bar mechanism. The kinematotropic characteristic of the mechanism is investigated and the geometric constrains deriving the kinematotropy are specified. The mechanism possesses two motion branches with different degrees of freedom. A detailed kinematic analysis is...
Article
Full-text available
This paper focuses on a diamond kinematotropic chain which is integrated in the construction of a new family of reconfigurable parallel mechanisms. The branch transition of the planar diamond kinematotropic chain is analyzed and the equivalent kinematic joints corresponding to each motion branch are identified. Kinematic limbs that can provide a co...
Article
In this paper, we present the design of two serial spherical mechanisms to substitute for a single spherical joint that is usually used to connect the platform with the base in three degrees of freedom parallel mechanisms. According to the principle derived from the conceptual design, through using the two serial spherical mechanisms as the constra...
Article
Full-text available
In this paper, a class of novel four Degrees of Freedom (DOF) non-overconstrained parallel mechanisms with large rotational workspace is presented based on screw theory. First, the conflict between the number of independent constraints applied on the moving platform and the number of kinematic limbs for 4-DOF non-overconstrained parallel mechanism...
Article
In this paper, a novel cable-driven parallel robot based on the motion characteristics of human ankle joint is proposed for ankle rehabilitation. Because of the novel mechanical design of the equivalent spherical joint and platform, the mechanism centre of rotations can easily match the ankle axes of rotations, which is an advantage over some exist...
Article
Full-text available
This paper presents the idea of constructing reconfigurable limbs by integrating metamorphic linkages as subchains. The planar five-bar metamorphic linkages that have three phases resulting from locking of motors are considered. Under the assumption that the constraint exerted by the reconfigurable limb can switch between no constraint, a constrain...
Article
Full-text available
In this paper, we present the design of a novel 3-RUS/RRR redundantly actuated parallel mechanism for ankle rehabilitation based on the principle from the conceptual design. The proposed mechanism can actualize the rotational movements of the ankle in three directions while at the same time the mechanism center of rotations can match the ankle axes...
Article
Full-text available
In this paper, the kinematic characteristics of Bennett mechanism and its corresponding regulus are analysed. The screw theory is employed for the analysis of twists and wrenches acted on the specific hyperboloid, and the common constraints are obtained. Through the DOF analysis, we find that the DOF of 4-R mechanism with its joint axes lying on a...
Article
This article presents a novel 3-DOF parallel manipulator extracted from an origami fold in the context of mechanisms. The parallel manipulator consists of a base, a platform and four chain-legs that connect the platform to base through revolute joints. Each chain-leg contains a closed-loop sub-chain, which is spherical 6R linkage with symmetrical a...
Article
Full-text available
This paper presents a unique feature of geometric constraint of adjacent axes of the variable-axis (vA) joint and analyses the effectiveness in the constructed limb, resulting in variation of mobility configuration of two 3S(v)PS(v) metamorphic parallel mechanisms. The underlying principle of the metamorphosis of this vA joint is unravelled by inve...
Article
Full-text available
In this article, a novel 4-RRCR parallel mechanism is introduced based on screw theory, and its kinematics and singularity are studied systematically. First, the degree of freedom analysis is performed using the screw theory. The formulas for solving the inverse and direct kinematics are derived. Second, a recursive elimination method is proposed t...
Article
Full-text available
Singularity analysis is an essential issue for the development and application of parallel manipulators. Most of the existing researches focus on the singularity of parallel manipulators are carried out based on the study of Jacobian matrices. A 3-DOF parallel manipulator with symmetrical structure is presented. The novel parallel manipulator emplo...
Article
This paper introduces the mathematical logical proposition into kinematics and presents a novel method for topological design and representation of mechanisms. The six-value non-classical logical matrix in three orders is proposed to represent spatial basic motions, relations, and selection of moving reference frame. The combinatorial logical sets...
Article
Based on the prototype of 3-UPU parallel mechanism proposed by Tsai, an improved 3-UPU parallel mechanism with three translational motions was designed and its constraint singularity was evaluated, thus a design method for improving the singularity characteristic of a 3-UPU parallel mechanism was created. First, through analysis of the terminal con...
Article
Full-text available
Based on the prototype of 3-UPU (universal-prismatic-universal joint) parallel mechanism proposed by Tsai [1], the parasitic rotation evaluation is performed and calculated the bound of instability of SNU (Seoul National University) 3-UPU parallel mechanism. Through analysis of the terminal constraint system of the 3-UPU parallel mechanism, the equ...
Article
Full-text available
A systematic method is developed for the type synthesis of 4-DOF nonoverconstrained parallel mechanisms with three translations and one rotation inspired by the design of H-4. First, the motion requirements of primary platform and secondary platform of the 4-DOF nonoverconstrained parallel mechanisms are analyzed, and the conflict between the numbe...
Conference Paper
High-efficiency and high-accuracy digital measurement for free-form surfaces is most important in reverse engineering. In this paper, a intelligent and high-efficiency sampling approach is presented. The coordinate measuring machine carry point laser probe to track the free-form surface. In the process of line-by-line sampling, the spacing of sampl...
Article
Full-text available
This paper presents a type-changeable kinematic pair with variable topology. The geometry properties and topological phases of the type-changeable kinematic joint are revealed. A novel reconfigurable parallel mechanism is evolved from the type-changeable kinematic pair according to geometric conditions of assemblages for parallel mechanisms. The pl...
Article
This paper presents adjacency matrix originated three-dimensional matrix for structural representation of mechanisms by integrating binary string in the sense of displacement subgroup theory. The improved elementary matrix operation for expressing of topological transformation of metamorphic mechanism is integrated in the three-dimensional matrix r...
Chapter
In this paper, a systematic approach is presented for the structural synthesis of a class of metamorphic parallel mechanisms which possess variable mobility. The metamorphic parallel mechanisms are constructed using limbs with lockable joints. When different joints are locked, the mechanisms will have different mobility from single degree of freedo...
Article
This paper presents a novel 4-DOF kinematotropic hybrid parallel manipulator. The topological structure allows for the realization of two translatory and two rotary output motions. Both the translations and rotations take place only in two orthogonal axes. The rotations are designed to possess the kinematotropic property, namely the output mobility...
Article
Full-text available
This paper takes the 3-UPU parallel manipulator which possesses 3-D pure translational motion as a studying case. The sensitivity of degree of freedom (DOF) characteristics and kinematic errors resulting from various kinds of assembly errors is observed. Kinematic model of the manipulator is established , therefore, typical assembly errors are enum...
Article
This paper analyzes the basic forms of 4-DOF spatial motions through the introduction of logical propositions for the topological structural synthesis of multiloop hybrid spatial mechanisms. The proposed method for the topological structural synthesis is based on displacement group theory and consists of two elements. First, spatial multiloop detac...
Article
This paper takes the 3-UPU parallel manipulator which possesses 3 translational and 1 revolute (3T1R) motions as a studying case. The sensitivity of degree of freedom (DOF) characteristics and kinematic errors resulting from various kinds of torsion angle errors is observed. Kinematic model of the manipulator is established and typical torsion angl...
Article
Full-text available
Based on the terminal constraints system (TCS) and reciprocal screw theory, a novel method is presented to determine the isotropic configurations of limited degree-of-freedom (DOF) parallel manipulators. From the available physical meaning of isotropy, the criteria to determine the isotropic configurations can be transformed to investigate whether...
Article
This paper investigates the geometry properties and certain restrictions of stroke induced by the special assemblage of a 3PUP parallel mechanism which consists of a fixed base, a platform and three limbs. The constraints exerted on the platform by a general PUP limb are analyzed based on screw theory. The disposition and analytical expression of a...
Article
This paper presents a novel method of structural synthesis and analysis of serial–parallel hybrid mechanisms with spatial multi-loop kinematic chains based on the displacement group theory. The topological arrangements of serial–parallel hybrid mechanisms can be developed by the Assur group transformation and fractal method to obtain the multi-loop...
Conference Paper
This paper presents two general metamorphic kinematic units which employ only revolute joints. The two kinematic units with reconfigurability are mapped from independent set of line vectors with different geometry. The underlying principle of the metamorphosis of this kind of reconfigurable kinematic units is unraveled by investigating the dependen...