scholarly journals CONTROLLER DESIGN BASED ON A KINEMATIC ESTIMATOR FOR A 3RRR PLANAR PARALLEL ROBOT DRIVEN BY ELECTRIC MOTORS

2020 ◽  
Vol 57 (6A) ◽  
pp. 95
Author(s):  
Nguyen Quang Hoang
Keyword(s):  
Controller Design ◽  
Parallel Robot ◽  
Degree Of Freedom ◽  
Kinematic Error ◽  
Electric Motors ◽  
Error Feedback ◽  
Auxiliary Variables ◽  
Generalized Coordinates ◽  
Novel Method ◽  
Moving Platform

The control of parallel robotic manipulator requires feedbacks of all the redundant coordinates and their derivatives. In practice, to have all feedback variables for the controller, a robot needs more sensors than its degree of freedom. These sensors measure not only the actuated joint variables, but also the auxiliary variables, position and velocity of the moving platform. In this paper, a novel method is introduced to estimate dependently generalized coordinates and motion of the moving platform. A kinematic error feedback technique is exploited to ensure the estimated motion converge to the actual motion of the robot.

scholarly journals CONTROLLER DESIGN BASED ON A KINEMATIC ESTIMATOR FOR A 3RRR PLANAR PARALLEL ROBOT DRIVEN BY ELECTRIC MOTORS

2020 ◽  
Vol 57 (6A) ◽  
pp. 95
Author(s):  
Nguyen Quang Hoang
Keyword(s):  
Controller Design ◽  
Parallel Robot ◽  
Degree Of Freedom ◽  
Kinematic Error ◽  
Electric Motors ◽  
Error Feedback ◽  
Auxiliary Variables ◽  
Generalized Coordinates ◽  
Novel Method ◽  
Moving Platform

The control of parallel robotic manipulator requires feedbacks of all the redundant coordinates and their derivatives. In practice, to have all feedback variables for the controller, a robot needs more sensors than its degree of freedom. These sensors measure not only the actuated joint variables, but also the auxiliary variables, position and velocity of the moving platform. In this paper, a novel method is introduced to estimate dependently generalized coordinates and motion of the moving platform. A kinematic error feedback technique is exploited to ensure the estimated motion converge to the actual motion of the robot.

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.

scholarly journals A Cable-Driven Parallel Robot With an Embedded Tilt-Roll Wrist

2019 ◽  
Author(s):  
Saman Lessanibahri ◽  
Philippe Cardou ◽  
Stéphane Caro
Keyword(s):  
Optimum Design ◽  
Parallel Robot ◽  
Visual Surveillance ◽  
Degree Of Freedom ◽  
Large Rotation ◽  
Fixed Frame ◽  
Workspace Analysis ◽  
Dynamic Performances ◽  
Moving Platform ◽  
Tomography Scanning

Abstract This paper addresses the optimum design, configuration and workspace analysis of a Cable-Driven Parallel Robot with an embedded tilt-roll wrist. The manipulator is a hybrid robot consisting in an under-constrained moving-platform accommodating a tilt-roll wrist. The embedded wrist provides large amplitudes of tilt and roll rotations and a large translational workspace obtained by the moving-platform. This manipulator is suitable for tasks requiring large rotation and translation workspaces like tomography scanning, camera-orienting devices and visual surveillance. The moving-platform is an eight-degree-of-freedom articulated mechanism with large translational and rotational workspaces and it is suspended from a fixed frame by six cables. The manipulator employs two bi-actuated cables, i.e., cable loops to transmit the power from motors fixed on the ground to the tilt-roll wrist. Therefore, the manipulator achieves better dynamic performances due to a lower inertia of its moving-platform.

scholarly journals A Cable-Driven Parallel Robot With An Embedded Tilt-Roll Wrist

2020 ◽  
Vol 12 (2) ◽  
Author(s):  
Saman Lessanibahri ◽  
Philippe Cardou ◽  
Stéphane Caro
Keyword(s):  
Optimum Design ◽  
Parallel Robot ◽  
Visual Surveillance ◽  
Degree Of Freedom ◽  
Large Rotation ◽  
Fixed Frame ◽  
Workspace Analysis ◽  
Dynamic Performances ◽  
Moving Platform ◽  
Tomography Scanning

Abstract This paper addresses the optimum design, configuration, and workspace analysis of a cable-driven parallel robot (CDPR) with an embedded tilt-roll wrist. The manipulator consists in a tilt-roll wrist mounted on the moving platform of a suspended CDPR. The embedded wrist provides large amplitudes of tilt and roll rotations and a large translational workspace obtained by the CDPR. This manipulator is suitable for tasks requiring large rotation and translation workspaces such as tomography scanning, camera-orienting devices, and visual surveillance. The moving-platform is an eight-degree-of-freedom articulated mechanism with large translational and rotational workspaces, and it is suspended from a fixed frame by six cables. The manipulator employs two bi-actuated cables, i.e., cable-loops to transmit the power from motors fixed on the ground to the tilt-roll wrist. Therefore, the manipulator achieves better dynamic performances due to a lower inertia of its moving-platform.

scholarly journals SLIDING MODE CONTROL FOR PARALLEL ROBOTS DRIVEN BY ELECTRIC MOTORS IN TASK SPACE

2018 ◽  
Vol 33 (4) ◽  
pp. 325-337 ◽  
Author(s):  
Nguyen Quang Hoang ◽  
Vu Duc Vuong
Keyword(s):  
Sliding Mode ◽  
Parallel Robot ◽  
Parallel Robots ◽  
Sliding Mode Controller ◽  
Electric Motors ◽  
Task Space ◽  
Generalized Coordinates ◽  
Lagrangian Equations ◽  
Operational Variables ◽  
Minimal Coordinates

This paper addresses the modelling of parallel robots including electric actuators. The dynamic model of the system is derived by applying the substructure method and Lagrangian equations with multipliers in form of redundant generalized coordinates. These equations are then transformed to the form of minimal coordinates of operational variables. Based on this form a sliding mode controller is designed for trajectory tracking in task space. Numerical simulations in MATLAB are carried out based on the 3RRR parallel robot in order to show the effectiveness of the proposal approach. The obtained results show a good behavior of the proposed task space tracking controller.

scholarly journals A New Method for Type Synthesis of 2R1T and 2T1R 3-DOF Redundant Actuated Parallel Mechanisms with Closed Loop Units

2020 ◽  
Vol 33 (1) ◽  
Author(s):  
Yongquan Li ◽  
Yang Zhang ◽  
Lijie Zhang
Keyword(s):  
Closed Loop ◽  
Screw Theory ◽  
Line Graph ◽  
Degree Of Freedom ◽  
Parallel Mechanisms ◽  
Type Synthesis ◽  
Allocation Criteria ◽  
Grassmann Line Geometry ◽  
Moving Platform ◽  
Atlas Method

Abstract The current type synthesis of the redundant actuated parallel mechanisms is adding active-actuated kinematic branches on the basis of the traditional parallel mechanisms, or using screw theory to perform multiple getting intersection and union to complete type synthesis. The number of redundant parallel mechanisms obtained by these two methods is limited. In this paper, based on Grassmann line geometry and Atlas method, a novel and effective method for type synthesis of redundant actuated parallel mechanisms (PMs) with closed-loop units is proposed. Firstly, the degree of freedom (DOF) and constraint line graph of the moving platform are determined successively, and redundant lines are added in constraint line graph to obtain the redundant constraint line graph and their equivalent line graph, and a branch constraint allocation scheme is formulated based on the allocation criteria. Secondly, a scheme is selected and redundant lines are added in the branch chains DOF graph to construct the redundant actuated branch chains with closed-loop units. Finally, the branch chains that meet the requirements of branch chains configuration criteria and F&C (degree of freedom & constraint) line graph are assembled. In this paper, two types of 2 rotational and 1 translational (2R1T) redundant actuated parallel mechanisms and one type of 2 translational and 1 rotational (2T1R) redundant actuated parallel mechanisms with few branches and closed-loop units were taken as examples, and 238, 92 and 15 new configurations were synthesized. All the mechanisms contain closed-loop units, and the mechanisms and the actuators both have good symmetry. Therefore, all the mechanisms have excellent comprehensive performance, in which the two rotational DOFs of the moving platform of 2R1T redundant actuated parallel mechanism can be independently controlled. The instantaneous analysis shows that all mechanisms are not instantaneous, which proves the feasibility and practicability of the method.

KINEMATICS AND WORKSPACE ANALYSIS OF A 3 DEGREE OF FREEDOM PARALLEL MECHANISM WITH PARALLELOGRAM LINKAGE

2017 ◽  
Vol 41 (5) ◽  
pp. 922-935
Author(s):  
HongJun San ◽  
JunSong Lei ◽  
JiuPeng Chen ◽  
ZhengMing Xiao ◽  
JunJie Zhao
Keyword(s):  
Monte Carlo ◽  
Monte Carlo Method ◽  
Analytical Method ◽  
Theoretical Basis ◽  
Parallel Mechanism ◽  
Graphical Method ◽  
Degree Of Freedom ◽  
Workspace Analysis ◽  
Fixed Base ◽  
Moving Platform

In this paper, a 3-DOF translational parallel mechanism with parallelogram linkage was studied. According to the space vector relation between the moving platform and the fixed base, the direct and inverse position solutions of this mechanism was deduced through analytical method. In addition, the error of the algorithm was analyzed, and the algorithm had turned out to be effective and to have the satisfactory computational precision. On the above basis, the workspace of this mechanism was found through graphical method, which was compared with that of finding through Monte Carlo method, and there was the feasibility for analyzing the workspace of the mechanism by graphical method. The characteristic of the mechanism was analyzed by comparing the results of two analysis methods, which provided a theoretical basis for the application of the mechanism.

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