Design of a Spatial Translation Mechanism by Optimizing Spatial Ground Structures and Its Kinematic Analysis

2018 ◽  
Vol 140 (8) ◽  
Author(s):  
Weidong Yu ◽  
Hao Wang ◽  
Genliang Chen ◽  
Longhai Zhao
Keyword(s):  
Degrees Of Freedom ◽  
Design Strategy ◽  
Forward Kinematics ◽  
The Novel ◽  
Revolute Joints ◽  
Closed Chain ◽  
Translation Mechanism ◽  
Spatial Translation ◽  
Ground Structures ◽  
Three Degrees Of Freedom

In our previous work, we designed a three-degrees-of-freedom (3DOF) translational parallel mechanism based on a proposed design strategy. In this paper, the design strategy is further improved, and a novel spatial translation mechanism (STM) is found. The novel STM consists of a platform, a base, and six modules between the platform and the base. Each module is a passive planar 6R single-loop closed chain, and it is connected with two other modules. Meanwhile, three modules are connected to the base, and the other three modules are connected to the platform. All the connections among the modules, platform, and base are realized by revolute joints. There are no obvious limbs in the mechanism due to the complex connections. The mobility of the STM is analyzed, and the forward kinematics is investigated. To validate the effectiveness and feasibility of the design, one prototype is fabricated. At the end of the paper, we draw some conclusions and discuss the future works.

scholarly journals Design and analysis of a 3-DOF planar micromanipulation stage with large rotational displacement for micromanipulation system

2017 ◽  
Vol 8 (1) ◽  
pp. 117-126 ◽  
Author(s):  
Bingxiao Ding ◽  
Yangmin Li ◽  
Xiao Xiao ◽  
Yirui Tang ◽  
Bin Li
Keyword(s):  
Nanoimprint Lithography ◽  
Inverse Kinematics ◽  
Degrees Of Freedom ◽  
Scanning Tunneling ◽  
Tunneling Microscopy ◽  
Rotational Displacement ◽  
Revolute Joints ◽  
Kinematic Models ◽  
Lever Mechanism ◽  
Three Degrees Of Freedom

Abstract. Flexure-based mechanisms have been widely used for scanning tunneling microscopy, nanoimprint lithography, fast servo tool system and micro/nano manipulation. In this paper, a novel planar micromanipulation stage with large rotational displacement is proposed. The designed monolithic manipulator has three degrees of freedom (DOF), i.e. two translations along the X and Y axes and one rotation around Z axis. In order to get a large workspace, the lever mechanism is adopted to magnify the stroke of the piezoelectric actuators and also the leaf beam flexure is utilized due to its large rotational scope. Different from conventional pre-tightening mechanism, a modified pre-tightening mechanism, which is less harmful to the stacked actuators, is proposed in this paper. Taking the circular flexure hinges and leaf beam flexures hinges as revolute joints, the forward kinematics and inverse kinematics models of this stage are derived. The workspace of the micromanipulator is finally obtained, which is based on the derived kinematic models.

Reconfigurable Mechanisms From the Intersection of Surfaces

2016 ◽  
Vol 8 (2) ◽  
Author(s):  
P. C. López-Custodio ◽  
J. M. Rico ◽  
J. J. Cervantes-Sánchez ◽  
G. I. Pérez-Soto
Keyword(s):  
Degrees Of Freedom ◽  
Kinematic Chain ◽  
Mobility Analysis ◽  
Revolute Joint ◽  
Revolute Joints ◽  
Reconfigurable Mechanisms ◽  
Three Degrees Of Freedom

The method of intersection of surfaces generated by kinematic dyads is applied to obtain mechanisms that are able to shift from one mode of motion to another. Then a mobility analysis shows that the singularities of the generated surfaces can be used to obtain mechanisms which can change their number of degrees-of-freedom depending on its configuration. The generator dyads are connected as usually done by a spherical pair. However, in the cases shown in this contribution the three-degrees-of-freedom of the spherical pair are not all necessary to keep the kinematic chain closed and movable, and the spherical pair can be substituted by either a pair of intersecting revolute joints or a single revolute joint. This substitution can be obtained by means of two methods presented in this contribution.

Kinematic Analysis of a New 3-DOF Translational Parallel Manipulator

2005 ◽  
Author(s):  
Yangmin Li ◽  
Qingsong Xu
Keyword(s):  
Inverse Kinematics ◽  
Parallel Manipulator ◽  
Degrees Of Freedom ◽  
Screw Theory ◽  
Industrial Applications ◽  
Forward Kinematics ◽  
Physical Constraints ◽  
Mechanical Joints ◽  
Reachable Workspace ◽  
Three Degrees Of Freedom

A novel three-degrees-of-freedom (3-DOF) translational parallel manipulator (TPM) with orthogonally arranged fixed actuators is proposed in this paper. The mobility of the manipulator is analyzed via screw theory. The inverse kinematics, forward kinematics, and velocity analyses are performed and the singularities and isotropic configurations are investigated in details afterwards. Under different cases of physical constraints imposed by mechanical joints, the reachable workspace of the manipulator is geometrically generated and compared. Especially, it is illustrated that the manipulator in principle possesses a fairly regular like workspace with a maximum cuboid defined as the usable workspace inscribed and one isotropic configuration involved. Furthermore, the singularity within the usable workspace is verified, and simulation results show that there exist no any singular configurations within the specified workspace. Therefore, the presented new manipulator has a great potential for high precision industrial applications such as assembly, machining, etc.

scholarly journals A novel multiple working modes parallel mechanism with variable workspace

2018 ◽  
Vol 234 (1) ◽  
pp. 211-224
Author(s):  
Dian Li ◽  
Sheng Guo ◽  
Haibo Qu
Keyword(s):  
Trajectory Planning ◽  
Parallel Mechanism ◽  
Degrees Of Freedom ◽  
Screw Theory ◽  
Forward Kinematics ◽  
3D Printer ◽  
Determination Method ◽  
Jacobian Matrices ◽  
Three Degrees Of Freedom

In this paper, a novel three-degrees-of-freedom multiple working modes parallel mechanism with variable workspace is proposed. Several studies including kinematic and prescribed trajectory planning are performed. First, the degrees of freedom of mechanism's two working modes are calculated based on screw theory. A prototype made by 3D printer also has been developed. Then, the inverse/forward kinematics and Jacobian matrices are obtained. The workspace and singularity are also analyzed, which show that the proposed parallel mechanism possesses singularity-free internal workspace. Finally, a working mode determination method is presented, which can be used to obtain suitable workspace in order to fully contain a prescribed trajectory. An example trajectory is used to verify the reasonability of the proposed method.

Performing Nonsingular Transitions Between Assembly Modes in Analytic Parallel Manipulators by Enclosing Quadruple Solutions

2015 ◽  
Vol 137 (12) ◽  
Author(s):  
Adrián Peidró ◽  
José María Marín ◽  
Arturo Gil ◽  
Óscar Reinoso
Keyword(s):  
Degrees Of Freedom ◽  
Parallel Manipulators ◽  
Joint Space ◽  
Parallel Robots ◽  
Forward Kinematics ◽  
Characteristic Polynomials ◽  
Forward Kinematic ◽  
Three Degrees Of Freedom

This paper analyzes the multiplicity of the solutions to forward kinematics of two classes of analytic robots: 2RPR-PR robots with a passive leg and 3-RPR robots with nonsimilar flat platform and base. Since their characteristic polynomials cannot have more than two valid roots, one may think that triple solutions, and hence nonsingular transitions between different assembly modes, are impossible for them. However, the authors show that the forward kinematic problems of these robots always admit quadruple solutions and obtain analytically the loci of points of the joint space where these solutions occur. Then, it is shown that performing trajectories in the joint space that enclose these points can produce nonsingular transitions, demonstrating that it is possible to design simple analytic parallel robots with two and three degrees-of-freedom (DOF) and the ability to execute these transitions.

A New 2T-2R Hybrid Parallel Manipulator

2011 ◽  
Vol 328-330 ◽  
pp. 1743-1746
Author(s):  
Wen Jia Chen ◽  
Lan Lei Zhao
Keyword(s):  
Computer Technology ◽  
Parallel Mechanism ◽  
Degrees Of Freedom ◽  
Virtual Manufacturing ◽  
Forward Kinematics ◽  
Nc Machine Tool ◽  
Nc Machine ◽  
Movable Platform ◽  
Parallel Platform ◽  
Three Degrees Of Freedom

Though computer technology has brought about virtual manufacturing to expedite design and analysis through simulation and visualization, machines remain essential, as ultimately products need to be made. There is a need for equipment providing more than three degrees of freedom (DOF) arranged in parallel and based on simpler arrangements than 6-DOF arrangements in application. This paper presents a new 4-DOF hybrid parallel platform manipulator with fixed-leg lengths and base mounted prismatic actuators. The movable platform of the manipulator can translate along two directions and rotate around two axes respectively (2T-2R). The kinematics model is formulated, which describes the inverse and forward kinematics transformation. It is very easy to develop a 5-axis NC machine-tool which is of large-workspace based on the 2T-2R, 4-DOF parallel mechanism presented in this paper.

scholarly journals A Parallel Manipulator With Only Translational Degrees of Freedom

1996 ◽  
Author(s):  
Lung-Wen Tsai ◽  
Richard Stamper
Keyword(s):  
Inverse Kinematics ◽  
Parallel Manipulator ◽  
Degrees Of Freedom ◽  
Translational Motion ◽  
Forward Kinematics ◽  
Closed Form Solutions ◽  
Real Solutions ◽  
Revolute Joints ◽  
Inverse Kinematics Problem ◽  
Three Degree Of Freedom

Abstract This paper presents a novel three degree of freedom parallel manipulator that employs only revolute joints and constrains the manipulator output to translational motion. Closed-form solutions are developed for both the inverse and forward kinematics. It is shown that the inverse kinematics problem has up to four real solutions, and the forward kinematics problem has up to 16 real solutions.

Kinematic Analysis and Design of a New 3-DOF Translational Parallel Manipulator

2005 ◽  
Vol 128 (4) ◽  
pp. 729-737 ◽  
Author(s):  
Yangmin Li ◽  
Qingsong Xu
Keyword(s):  
Inverse Kinematics ◽  
Parallel Manipulator ◽  
Degrees Of Freedom ◽  
Screw Theory ◽  
Forward Kinematics ◽  
Velocity Analysis ◽  
Analysis And Design ◽  
Reachable Workspace ◽  
Three Degrees Of Freedom ◽  
Real Machine

A new three degrees of freedom (3-DOF) translational parallel manipulator (TPM) with fixed actuators called a 3-PRC TPM is proposed in this paper. The mobility of the manipulator is analyzed via screw theory. The inverse kinematics, forward kinematics, and velocity analysis are performed and the singular and isotropic configurations are identified afterward. Moreover, the mechanism design to eliminate all singularities and generate an isotropic manipulator has been presented. With the variation on architectural parameters, the reachable workspace of the manipulator is generated and compared. Especially, it is illustrated that the manipulator in principle possesses a uniform workspace with a constant hexagon shape cross section. Furthermore, the dexterity characteristics are investigated in the local and global sense, respectively, and some considerations for real machine design have been proposed as well.

Kinematic Analysis and Design of a Novel Shoulder Exoskeleton Using a Double Parallelogram Linkage

2018 ◽  
Vol 10 (4) ◽  
Author(s):  
Simon Christensen ◽  
Shaoping Bai
Keyword(s):  
Shoulder Joint ◽  
Degrees Of Freedom ◽  
Large Range ◽  
Upper Body ◽  
Element Analysis ◽  
Analysis And Design ◽  
Revolute Joints ◽  
Current State ◽  
Spherical Mechanism ◽  
Three Degrees Of Freedom

The design of an innovative spherical mechanism with three degrees-of-freedom (DOFs) for a shoulder joint exoskeleton is presented in this paper. The spherical mechanism is designed with a double parallelogram linkage (DPL), which connects two revolute joints to implement the motion as a spherical joint, while maintaining the remote center (RC) of rotation. The design has several new features compared to the current state-of-the-art: (1) a relative large range of motion (RoM) free of singularity, (2) high overall stiffness, (3) lightweight, and (4) compact, which make it suitable for assistive exoskeletons. In this paper, the kinematics and singularities are analyzed for the spherical mechanism and DPL. Dimensional analysis is carried out to find the design with maximum RoM. The new shoulder joint is finally designed, constructed, and integrated in a four degree-of-freedom wearable upper-body exoskeleton. A finite element analysis (FEA) study is used to assess the structural stiffness of the proposed design in comparison to the conventional 3R mechanism.

Motion Control Concepts for the Hydraulic Infinite Linear Actuator

2016 ◽  
Author(s):  
Martin Hochwallner ◽  
Petter Krus
Keyword(s):  
Motion Control ◽  
Digital Control ◽  
Hydraulic System ◽  
Degrees Of Freedom ◽  
The Other ◽  
Linear Actuator ◽  
The Novel ◽  
Smooth Motion ◽  
Three Degrees Of Freedom ◽  
Infinite Linear

This contribution presents the novel Hydraulic Infinite Linear Actuator (HILA). It focuses on the control of motion and is based on simulation and analysis. The novel actuator consists of two symmetric double acting cylinders with a common piston rod and hydraulically detachable pistons. Alternatingly one cylinder engages and drives the load while the other retracts, the HILA thus works in a kind of rope climbing motion. The purpose of this contribution is to study the motion control of the HILA and to mimic the behaviour of a conventional cylinder. The HILA has three degrees of freedom which are temporarily coupled compared with one in a conventional cylinder. Further, the HILA with the chosen hydraulic system has two continuous and two digital control inputs. The challenge to be tackled is to combine the short stroke back and forth motions of the cylinders into a continuous smooth motion ofthe whole actuator. Results from simulations and analyses show that the investigated concepts can keep the jerk within acceptable limits for many applications.

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