scholarly journals Dynamic and Wrench-Feasible Workspace Analysis of a Cable-Driven Parallel Robot Considering a Nonlinear Cable Tension Model

2021 ◽  
Vol 12 (1) ◽  
pp. 244
Author(s):  
Vu N. D. Kieu ◽  
Shyh-Chour Huang
Keyword(s):  
Parallel Robot ◽  
Mechanical Analysis ◽  
Industrial Applications ◽  
Parallel Robots ◽  
Kinematic Equation ◽  
Cable Tension ◽  
End Effector ◽  
Tension Distribution ◽  
Workspace Analysis ◽  
High Dynamics

Cable-driven parallel robots (CDPRs) have several advantages and have been widely used in many industrial fields, especially industrial applications that require high dynamics, high payload capacity, and a large workspace. In this study, a design model for a CDPR system was proposed, and kinematic and dynamic modeling of the system was performed. Experiments were carried out to identify the dynamic modulus of elastic cables based on the dynamic mechanical analysis (DMA) method. A modified kinematic equation considering cable nonlinear tension was developed to determine the optimal cable tension at each position of the end-effector, and the wrench-feasible workspace was analyzed at various motion accelerations. The simulation results show that the proposed CDPR system obtains a large workspace, and the overall workspace is satisfactory and unrestricted for moving ranges in directions limited by the X-axis and the Y-axis from −0.3 to 0.3 m and by the Z-axis from 0.1 to 0.7 m. The overall workspace was found to depend on the condition of acceleration as well as the moving ranges limited by the end-effector. With an increase in external acceleration, the cable tension distribution increased and reached a maximum in the case of 100 m/s2.

Workspace Analysis of Cable-Driven Parallel Robot With Coulomb Friction Under Ultra-High-Acceleration

2016 ◽  
Author(s):  
Jun-Mu Heo ◽  
Sung-hyun Choi ◽  
Kyoung-Su Park
Keyword(s):  
Coulomb Friction ◽  
Parallel Robot ◽  
Parallel Robots ◽  
End Effector ◽  
High Acceleration ◽  
Workspace Analysis

Cable driven parallel robots (CDPRs) are a class of parallel robots in which the rigid links are replaced by cables. It consists of a moving end-effector and a number of active cables connected to the end-effector.

scholarly journals Potential Energy Distribution of Redundant Cable-Driven Robot Applied to Compliant Grippers: Method and Computational Analysis

Sensors ◽  
2019 ◽  
Vol 19 (15) ◽  
pp. 3403 ◽  
Author(s):  
Rodriguez-Barroso ◽  
Saltaren ◽  
Portilla ◽  
Cely ◽  
Yakrangi
Keyword(s):  
Energy Distribution ◽  
Parallel Robot ◽  
Parallel Robots ◽  
Potential Energy Distribution ◽  
End Effector ◽  
Tension Distribution ◽  
Multibody Dynamic ◽  
Compliant Actuators ◽  
Dynamic Software ◽  
The Relationship

Cable-driven parallel robots with a redundant configuration have infinite solutions for their cable tension distribution to provide a specific wrench to the end-effector. Redundancy is commonly used to increase the workspace and stiffness or to achieve secondary objectives like energetic minimization or additional movements. This article presents a method based on energy distribution to handle the redundancy of cable-driven parallel robots. This method allows the deformation and tension of each link to be related to the total energy available in the parallel robot. The study of energy distribution expression allows deformation, tension, and position to be combined. It also defines the range of tension and deformation that cables can achieve without altering the wrench exerted on the end-effector. This range is used with a passive reconfigurable end-effector to control the position of two grippers attached to some cables which act as compliant actuators. The relationship between the actuators’ energy and their corresponding gripper positions is also provided. In this way, energy measurement from the actuators allows the grasping state to be sensed. The results are validated using multibody dynamic software.

scholarly journals Modal Control for Active Vibration Damping of Cable-Driven Parallel Robots

2020 ◽  
Vol 12 (5) ◽  
Author(s):  
Loïc Cuvillon ◽  
Xavier Weber ◽  
Jacques Gangloff
Keyword(s):  
Degrees Of Freedom ◽  
Transfer Functions ◽  
Parallel Robot ◽  
Vibration Damping ◽  
Parallel Robots ◽  
Robot Dynamics ◽  
End Effector ◽  
Active Vibration Damping ◽  
Active Vibration ◽  
High Dynamics

Abstract Cable-driven parallel robots are well suited for applications that require a very large workspace. Thanks to their lightweight moving parts, they can achieve high dynamics while remaining pretty safe for nearby human workers. Furthermore, their size depends only on the length of the cables; thus, their scale is almost totally decoupled from their cost. However, due to the cables, the stiffness is very low with respect to rigid link robots, inducing slowly damped oscillations of the end effector. Previous works have shown that those vibrations can be effectively damped by the winch actuators thanks to active vibration damping techniques. In this paper, a gain scheduling approach is proposed based on a linearized model of the robot dynamics. This model is projected in the modal space yielding six decoupled transfer functions for six degrees-of-freedom (DoFs) of a cable-driven parallel robot using thin cables. The stability of the proposed control law is analyzed for a static and a moving end effector. The proposed control algorithm is validated experimentally on an eight-cable suspended robot prototype.

scholarly journals Kinematics and Workspace Analysis of a 3PPPS Parallel Robot With U-Shaped Base

2017 ◽  
Author(s):  
Damien Chablat ◽  
Luc Baron ◽  
Ranjan Jha
Keyword(s):  
Kinematic Analysis ◽  
Inverse Kinematics ◽  
Parallel Robot ◽  
Joint Space ◽  
Industrial Applications ◽  
End Effector ◽  
Workspace Analysis ◽  
Discriminant Variety ◽  
Number Of Cells ◽  
Selection Of

This paper presents the kinematic analysis of the 3-PPPS parallel robot with an equilateral mobile platform and a U-shape base. The proposed design and appropriate selection of parameters allow to formulate simpler direct and inverse kinematics for the manipulator under study. The parallel singularities associated with the manipulator depend only on the orientation of the end-effector, and thus depend only on the orientation of the end effector. The quaternion parameters are used to represent the aspects, i.e. the singularity free regions of the workspace. A cylindrical algebraic decomposition is used to characterize the workspace and joint space with a low number of cells. The discriminant variety is obtained to describe the boundaries of each cell. With these simplifications, the 3-PPPS parallel robot with proposed design can be claimed as the simplest 6 DOF robot, which further makes it useful for the industrial applications.

scholarly journals Wrench-Feasible Workspace of Mobile Cable-Driven Parallel Robots

2020 ◽  
Vol 12 (3) ◽  
Author(s):  
Tahir Rasheed ◽  
Philip Long ◽  
Stéphane Caro
Keyword(s):  
Convex Hull ◽  
Case Studies ◽  
High Speed ◽  
Parallel Robot ◽  
Parallel Robots ◽  
Static Equilibrium ◽  
Equilibrium Conditions ◽  
Cable Tension ◽  
End Effector ◽  
Novel Concept

Abstract Cable-driven parallel robots (CDPRs) hold numerous advantages over conventional parallel robots in terms of high speed and large workspace. Cable-driven parallel robots whose workspace can be further increased by the modification of their geometric architecture are known as reconfigurable cable-driven parallel robots. A novel concept of reconfigurable cable-driven parallel robots that consists of a classical cable-driven parallel robot mounted on multiple mobile bases is known as mobile CDPR. This paper proposes a methodology to trace the wrench-feasible workspace of mobile cable-driven parallel robots by determining its available wrench set. Contrary to classical cable-driven parallel robots, we show that the available wrench set of a mobile cable-driven parallel robot depends, not only on the cable tension limits but also on the static equilibrium conditions of the mobile bases. The available wrench set is constructed by two different approaches known as convex hull approach and hyperplane shifting method. Three case studies are carried out for the validation of the proposed methodology. The proposed approach is experimentally validated on a mobile cable-driven parallel robot with a point-mass end-effector and two mobile bases.

scholarly journals Dynamic and Oscillatory Motions of Cable-Driven Parallel Robots Based on a Nonlinear Cable Tension Model

2017 ◽  
Vol 9 (6) ◽  
Author(s):  
Sana Baklouti ◽  
Eric Courteille ◽  
Stéphane Caro ◽  
Mohamed Dkhil
Keyword(s):  
Dynamic Response ◽  
Dynamic Modeling ◽  
Dynamic Modulus ◽  
Mechanical Analysis ◽  
Parallel Robots ◽  
Original Formulation ◽  
Cable Tension ◽  
End Effector ◽  
Numerical Investigations ◽  
Softening Behavior

In this paper, dynamic modeling of cable-driven parallel robots (CDPRs) is addressed where each cable length is subjected to variations during operation. It is focusing on an original formulation of cable tension, which reveals a softening behavior when strains become large. The dynamic modulus of cable elasticity is experimentally identified through dynamic mechanical analysis (DMA). Numerical investigations carried out on suspended CDPRs with different sizes show the effect of the proposed tension formulation on the dynamic response of the end-effector.

Simultaneous base and tool calibration for self-calibrated parallel robots

Robotica ◽  
2002 ◽  
Vol 20 (4) ◽  
pp. 367-374 ◽  
Author(s):  
Guilin Yang ◽  
I-Ming Chen ◽  
Song Huat Yeo ◽  
Wee Kiat Lim
Keyword(s):  
Parallel Robot ◽  
Parallel Robots ◽  
Sufficient Accuracy ◽  
Least Square ◽  
Mobile Platform ◽  
Calibration Model ◽  
End Effector ◽  
The World ◽  
Kinematic Transformation ◽  
Kinematic Errors

In this paper, we focus on the base and tool calibration of a self-calibrated parallel robot. After the self-calibration of a parellel robot by using the built-in sensors in the passive joints, its kinematic transformation from the robot base to the mobile platform frame can be computed with sufficient accuracy. The base and tool calibration, hence, is to identify the kinematic errors in the fixed transformations from the world frame to the robot base frame and from the mobile platform frame to the tool (end-effector) frame in order to improve the absolute positioning accuracy of the robot. Using the mathematical tools from group theory and differential geometry, a simultaneous base and tool calibration model is formulated. Since the kinematic errors in a kinematic transformation can be represented by a twist, i.e. an element of se(3), the resultant calibration model is simple, explicit and geometrically meaningful. A least-square algorithm is employed to iteratively identify the error parameters. The simulation example shows that all the preset kinematic errors can be fully recovered within three to four iterations.

Stiffness estimation of a parallel manipulator using image analysis and camera calibration techniques

Robotica ◽  
2012 ◽  
Vol 31 (4) ◽  
pp. 657-667 ◽  
Author(s):  
Abraham Gonzalez-Hernandez ◽  
Eduardo Castillo-Castaneda
Keyword(s):  
Image Analysis ◽  
Camera Calibration ◽  
Parallel Manipulator ◽  
Parallel Robot ◽  
Parallel Robots ◽  
Mobile Platform ◽  
End Effector ◽  
Simple Implementation ◽  
Specific Position ◽  
Calibration Techniques

SUMMARYThis work presents a methodology using image analysis to estimate the experimental stiffness of a parallel robot, Parallix LKF-2040, a 3-degree-of-freedom manipulator. The proposed methodology has a simple implementation and can be applied to different architectures of parallel robots. This methodology uses image analysis and camera calibration techniques to estimate compliant displacements of mobile platform produced by several loads at the end effector level, and calculate stiffness in a specific position of mobile platform. Experimental results are presented for different positions within the workspace.

Design and Development of a Novel 2-Degree-of-Freedom Parallel Robot

Robotica ◽  
2019 ◽  
Vol 38 (1) ◽  
pp. 1-14
Author(s):  
Changxi Cheng ◽  
Wenkai Huang ◽  
Chunliang Zhang
Keyword(s):  
Structural Design ◽  
Medical Science ◽  
Parallel Robot ◽  
Parallel Robots ◽  
Degree Of Freedom ◽  
Static Stiffness ◽  
Reachable Workspace ◽  
Workspace Analysis ◽  
Potential Applications ◽  
Speed Performance

SummaryParallel robots are widely used in the fields of manufacturing, medical science, education, scientific research, etc. Many studies have been conducted on the topic already. However, shortcomings still exist, especially in certain situations. To meet the demand of good speed and load performances at the same time, this work presents a novel 2-degree-of-freedom parallel robot. The structural design, static, stiffness, and reachable workspace analysis of the robot are given in the manuscript. Experiment regarding the accuracy and speed performance is conducted, and the results are provided. In the end, potential applications of the proposed robot are suggested.

DeltaBot: A New Cable-Based Ultra High Speed Robot

2003 ◽  
Author(s):  
Saeed Behzadipour ◽  
Robert Dekker ◽  
Amir Khajepour ◽  
Edmon Chan
Keyword(s):  
High Speed ◽  
Degrees Of Freedom ◽  
Manufacturing Industry ◽  
Design Procedure ◽  
Parallel Manipulators ◽  
Parallel Robot ◽  
Parallel Robots ◽  
Manufacturing Cost ◽  
End Effector ◽  
Serial Manipulators

The growing needs for high speed positioning devices in the automated manufacturing industry have been challenged by robotic science for more than two decades. Parallel manipulators have been widely used for this purpose due to their advantage of lower moving inertia over the conventional serial manipulators. Cable actuated parallel robots were introduced in 1980’s to reduce the moving inertia even further. In this work, a new cable-based parallel robot is introduced. For this robot, the cables are used not only to actuate the end-effector but also to apply the necessary kinematic constraints to provide three pure translational degrees of freedom. In order to maintain tension in the cables, a passive air cylinder is used to push the end-effector against the stationary platform. In addition to low moving inertia, the new design benefits from simplicity and low manufacturing cost by eliminating joints from the robot’s mechanism. The design procedure and the results of experiments will be discussed in the following.

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