scholarly journals Design and Analysis of a Novel Schönflies Motion Parallel Robot with Full Cycle Rotation

2021 ◽  
Author(s):  
Luquan Li ◽  
Yuefa Fang ◽  
Lin Wang ◽  
Jiaqiang Yao
Keyword(s):  
Complex Dynamics ◽  
Virtual Work ◽  
Parallel Robot ◽  
Singularity Analysis ◽  
Parallel Robots ◽  
The Novel ◽  
Scara Robot ◽  
Pick And Place ◽  
Place Task ◽  
Schönflies Motion

Abstract 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 robot with full cycle rotation, the robot can generate Schönflies motion by the most simplified structure. The novel Schönflies motion parallel robot is a two-limb parallel mechanism with least links and joints, and each limb is driven by a 2-degree of freedom (DOF) cylindrical driver (C-driver). The full cycle rotation of the output link is achieved by “…R-H…” structure, where the revolute (R) and helical (H) joints are coaxial. Mobility, kinematics, workspace and singularity analysis of novel Schönflies motion parallel robot are analyzed. Then, dynamic model is formulated based on the principle of virtual work. Moreover, a pick-and-place task is implemented by proposed Schönflies motion parallel robot and a serial SCARA robot, respectively. The simulation results verify the correctness of the theoretical model. Furthermore, dynamics performances of Schönflies motion parallel robot and serial SCARA robot are compared, which reveal the performance merits of proposed Schönflies motion parallel robot.

Kinematics and Stiffness Modeling of a 4-DOF Parallel Robot for Schönflies Motion Generation

2014 ◽  
Author(s):  
Shaoping Bai ◽  
Lasse Køgs Andersen ◽  
Carsten Rebbe Mølgaard
Keyword(s):  
Dynamic Performance ◽  
Parallel Robot ◽  
Parallel Robots ◽  
Motion Generation ◽  
Stiffness Modeling ◽  
Pick And Place ◽  
Fea Simulation ◽  
Schönflies Motion ◽  
Pick And Place Operation ◽  
Good Agreement

This work deals with the design of parallel robots for the generation of pick-and-place operation, or Schönflies motion. The aim is to develop a robot with workspace optimized for fast pick-and-place operations, namely, a robot with a superellipsoidal reachable volume, which suits best for the pick-and-place operations on conveyers, where robots’ working areas are nearly rectangular. In this paper, the kinematics and stiffness modeling of the new robot are presented. A method of stiffness modeling by means of Castigliano’s Theorem is developed. Using the new method, the stiffness of the robot is analyzed. The results are compared with FEA simulation, which shows a good agreement between the results. The method is finally applied to the engineering design of the new robot for enhanced static and dynamic performance.

On Force and Motion Control of Serial-Parallel Robots

1996 ◽  
Author(s):  
Shih-Liang Wang
Keyword(s):  
Control Algorithm ◽  
Virtual Work ◽  
Parallel Robot ◽  
Parallel Robots ◽  
Joint Torque ◽  
Compact Structure ◽  
Serial Robots ◽  
S Matrix ◽  
Serial Robot ◽  
Rate Control Algorithm

Abstract A serial-parallel robot has the high stiffness and accuracy of a parallel robot, and a large workspace and compact structure of a serial robot. In this paper, the resolved force control algorithm is derived for serial-parallel robots, including a 3-articulated-arm platform robot, a linkage robot, and two cooperating serial robots. A S matrix is derived to relate joint torque to the external load. Using the principle of virtual work, S is used in resolved rate control algorithm to relate the tool velocity to joint rate. S can be easily expanded to the control of redundant actuation, and it can be used to interpret singularity. MATLAB is used to verify these control algorithms with graphical motion animation.

Singularity Analysis of a Plane-Symmetry 3-RPS Parallel Robot Based on Translational/Rotational Jacobian Matrices

2011 ◽  
Vol 121-126 ◽  
pp. 1590-1594
Author(s):  
Yan Shi ◽  
Hong Xin Yue ◽  
Yi Lu ◽  
Lian He Guo
Keyword(s):  
Jacobian Matrix ◽  
Parallel Robot ◽  
Singularity Analysis ◽  
Parallel Robots ◽  
New Method ◽  
Plane Symmetry ◽  
Jacobian Matrices ◽  
Different Types

Firstly, 3-DOF parallel robots were classified into different types from the view of moving form. A new method of analyzing the singularity of 3-DOF parallel robots was introduced, which is based on translational Jacobian matrix and rotational Jacobian matrix. The singularity of parallel robots with pure translational form and pure rotational form was introduced summarily. Secondly, the process of solving the plane-symmetry 3-RPS parallel robot with combined moving forms was focused on, through which translational Jacobian matrix and rotational Jacobian matrix were adopted. Finally, the solving results were compared with the axis-symmetry 3-RPS parallel robot, which showed more general singularity can be solved through the new method.

scholarly journals Optimal Kinematic Redundancy Planning for Planar Mobile Cable-Driven Parallel Robots

2018 ◽  
Author(s):  
Tahir Rasheed ◽  
Philip Long ◽  
David Marquez-Gamez ◽  
Stéphane Caro
Keyword(s):  
Parallel Robot ◽  
Parallel Robots ◽  
Degree Of Freedom ◽  
Static Equilibrium ◽  
Kinematic Redundancy ◽  
Pick And Place ◽  
Moving Platform ◽  
Three Degree Of Freedom

Mobile Cable-Driven Parallel Robots (MCDPRs) are special type of Reconfigurable Cable Driven Parallel Robots (RCDPRs) with the ability of undergoing an autonomous change in their geometric architecture. MCDPRs consists of a classical Cable-Driven Parallel Robot (CDPR) carried by multiple Mobile Bases (MBs). Generally MCDPRs are kinematically redundant due to the additional mobilities generated by the motion of the MBs. As a consequence, this paper introduces a methodology that aims to determine the best kinematic redundancy scheme of Planar MCDPRs (PMCDPRs) with one degree of kinematic redundancy for pick-and-place operations. This paper also discusses the Static Equilibrium (SE) constraints of the PMCDPR MBs that are needed to be respected during the task. A case study of a PMCDPR with two MBs, four cables and a three degree-of-freedom (DoF) Moving Platform (MP) is considered.

Development of a Five-Bar Parallel Robot With Large Workspace

2010 ◽  
Author(s):  
Lucas Campos ◽  
Francis Bourbonnais ◽  
Ilian A. Bonev ◽  
Pascal Bigras
Keyword(s):  
Parallel Robot ◽  
Parallel Robots ◽  
Industrial Grade ◽  
Pick And Place

Five-bar planar parallel robots for pick and place operations are always designed so that their singularity loci are significantly reduced. In these robots, the length of the proximal links is different from the length of the distal links. As a consequence, the workspace of the robot is significantly limited, since there are holes in it. In contrast, we propose a design in which all four links have equal lengths. Since such a design leads to more parallel singularities, a strategy for avoiding them by switching working modes is proposed. As a result, the usable workspace of the robot is significantly increased. The idea has been implemented on an industrial-grade prototype and the latter is described in detail.

Dynamic Analysis of a Parallel Pick-and-Place Robot With Flexible Links

2008 ◽  
Author(s):  
Haihong Li ◽  
Zhiyong Yang
Keyword(s):  
High Speed ◽  
Dynamic Performance ◽  
Lithium Ion ◽  
Parallel Robot ◽  
Parallel Robots ◽  
Modeling And Analysis ◽  
Flexible Links ◽  
Pick And Place ◽  
Floating Frame ◽  
Pick And Place Operation

The dynamic modeling and analysis of a 2-DOF translational parallel robot for high-speed pick-and-place operation was presented. Considering the flexibility of all links, the governing equation of motion of a flexible link is formulated in the floating frame of reference using Euler-Lagrange method. A kineto-elasto dynamic model of the system is achieved, ready for modal analysis. Simulation in FEM software showed the similar modes with above computational result in typical location and rotation. The dynamic experiment presented the dominant modes and proved the theoretical analysis and simulation. The Diamond robot used in Lithium-ion battery sorting was taken as an example to demonstrate how to finish above studies. The result shows that the mechanism has good dynamic performance. The work is available for all parallel robots with flexible links.

scholarly journals Kinematics, Workspace, and Singularity Analysis of a Parallel Robot With Five Operation Modes

2018 ◽  
Vol 10 (3) ◽  
Author(s):  
Damien Chablat ◽  
Xianwen Kong ◽  
Chengwei Zhang
Keyword(s):  
Degrees Of Freedom ◽  
Rotation Axis ◽  
Operation Mode ◽  
Parallel Robot ◽  
Joint Space ◽  
Singularity Analysis ◽  
Parallel Robots ◽  
Operation Modes ◽  
Serial Chain ◽  
Kinematic Study

Most multimode parallel robots can change operation modes by passing through constraint singularities. This paper deals with a comprehensive kinematic study of a three degrees-of-freedom (DOF) multimode three-PRPiR parallel robot developed at Heriot-watt University. This robot is able to reach several operation modes without crossing any constraint singularity by using lockable Pi and R joints. Here, a Pi joint may act as a 1DOF planar parallelogram if its lockable P (prismatic) joint is locked or a 2DOF RR serial chain if its lockable P joint is released. The operation modes of the robot include a 3T operation mode and four 2T1R operation modes with two different directions of the rotation axis of the moving platform. The inverse kinematics and forward kinematics of the robot in each operation mode are dealt with in detail. The joint space and workspace analysis of the robot allow us to know the regions of the workspace that the robot can reach in each operation mode. It is shown that the robot is able to change assembly mode in one operation mode by passing through another operation mode.

On the Singularities of DELTA Parallel Robots

2015 ◽  
Vol 762 ◽  
pp. 125-130
Author(s):  
Luciana Cristina Dudici ◽  
Ion Simionescu
Keyword(s):  
Jacobian Matrix ◽  
Equation System ◽  
Parallel Robot ◽  
Singularity Analysis ◽  
Parallel Robots ◽  
Jacobian Determinant ◽  
Transformation Matrices ◽  
Geometric Conditions ◽  
Major Disadvantage ◽  
Analysis Equation

The major disadvantage of the parallel robot is that the singular positions are comprised into the work space. The singular positions are the particular poses for parallel robot DELTA where the mobility of the structure is not longer zero when the actuators are locked. Present analysis is focused on the determinant value of the Jacobian matrix of the kinematic analysis equation system, written using Denavit – Hartenberg transformation matrices. The kinematic equations possess the algebraic and trigonometric character, so that the inverse singularity analysis can be formulated. By instantaneous mobility analysis of the moving platform of the parallel robots, the geometric conditions for the forward singularity configurations are identified. Finally, a numerical example is solved in order to illustrate the variation of the Jacobian determinant in the proximity of a singular position.

High-order singularities of 5R planar parallel robots

Robotica ◽  
2018 ◽  
Vol 37 (2) ◽  
pp. 233-245 ◽  
Author(s):  
Mustafa Özdemir
Keyword(s):  
Time Derivative ◽  
Parallel Manipulators ◽  
Parallel Robot ◽  
Singularity Analysis ◽  
Research Field ◽  
Parallel Robots ◽  
High Order ◽  
Inverse Dynamic ◽  
Active Research ◽  
Order Parallel

SUMMARYSingularity analysis of parallel manipulators is an active research field in robotics. The present article derives for the first time in the literature a condition under which a five-bar parallel robot encounters high-order parallel singularities. In this regard, by focusing on the planar 5R mechanism, a theorem is given in terms of the slope of its coupler curve at the parallel singular configurations. At high-order parallel singularities, the associated determinant vanishes simultaneously with at least its first-order time derivative. The determination of such singularities is quite important since in their presence, some special conditions should be satisfied for bounded inverse dynamic solutions.

Numerical Framework and Design Optimization of an Intrinsically Compliant 3-DOF Parallel Robot

2020 ◽  
Vol 21 (2) ◽  
Author(s):  
Shahid Hussain ◽  
Prashant K. Jamwal ◽  
Akim Kapsalyamov ◽  
Mergen H. Ghayesh
Keyword(s):  
Degrees Of Freedom ◽  
Parallel Robot ◽  
Singularity Analysis ◽  
Parallel Robots ◽  
Simultaneous Optimization ◽  
Design Synthesis ◽  
Pneumatic Muscle ◽  
Nonlinear Motion ◽  
Strength Pareto Evolutionary Algorithm ◽  
Muscle Actuators

Abstract Parallel robots are multiple degrees of freedom (DOFs) systems that are typically used in applications characterized by enhanced accuracy, rigidity, and large force requirements within a compact workspace. In the present research, an intrinsically compliant parallel robot with 3-DOFs, actuated using four pneumatic muscle actuators (PMA), is conceptualized, developed, and analyzed. Despite many benefits, parallel robots also offer certain challenges that arise from the highly coupled and nonlinear motion of their actuators. The small workspace of parallel robots has many singularities and solving a closed-form forward kinematics (FK) for its end-effector motion is complicated. The PMAs can provide intrinsically compliant robotic motions, however, since they are flexible, their unilateral actuation also poses constraints on the achievable DOFs. The present research focuses on analyzing kinematics and dynamics of the developed parallel robot incorporating the stiffness together with force closure analyses besides suggesting design improvements as a consequence of the singularity analysis. Design synthesis and multi-criteria optimization have been performed to obtain a robot design which may provide higher accuracies (near unity condition number), quick response to external wrench (stiffness and rigidity), and reduced actuator force requirements. SPEA2 (Improved Strength Pareto Evolutionary Algorithm) has been implemented to carry out the simultaneous optimization of design objectives and provide Pareto optimal design solutions.

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