A Low-Cost Hexa Platform for Efficient Force Control Systems Using Industrial Manipulators

2009 ◽  
Vol 147-149 ◽  
pp. 1-6 ◽  
Author(s):  
Rafal Osypiuk ◽  
Torsten Kröger
Keyword(s):  
Control Systems ◽  
Force Control ◽  
Execution Time ◽  
Low Cost ◽  
Degree Of Freedom ◽  
Industrial Manipulators ◽  
Control Concept ◽  
Six Dof ◽  
Parallel Platform ◽  
Six Degree Of Freedom

This contribution presents a new force control concept for industrial six-degree of freedom (DOF) manipulators, which uses a Hexa platform that provides an active environmental stiffness for all six DOFs. The paper focuses on the Hexa platform and is split into two essential parts: (i) parallel platform construction, and (ii) application of force control with industrial manipulators using a six-DOF environmental stiffness. This mechatronic solution almost gives one hundred percent robustness for stiffness changes in the environment, what guaranties a significant shortening of execution time.

scholarly journals A singularity handling algorithm based on operational space control for six-degree-of-freedom anthropomorphic manipulators

2019 ◽  
Vol 16 (3) ◽  
pp. 172988141985891
Author(s):  
Zhi-Hao Kang ◽  
Ching-An Cheng ◽  
Han-Pang Huang
Keyword(s):  
Null Space ◽  
Singularity Analysis ◽  
Degree Of Freedom ◽  
Control Input ◽  
Real Time Control ◽  
Time Control ◽  
Operational Space ◽  
Industrial Manipulators ◽  
Space Motion ◽  
Six Degree Of Freedom

In this article, we analyze the singularities of six-degree-of-freedom anthropomorphic manipulators and design a singularity handling algorithm that can smoothly go through singular regions. We show that the boundary singularity and the internal singularity points of six-degree-of-freedom anthropomorphic manipulators can be identified through a singularity analysis, although they do not possess the nice kinematic decoupling property as six-degree-of-freedom industrial manipulators. Based on this discovery, our algorithm adopts a switching strategy to handle these two cases. For boundary singularities, the algorithm modifies the control input to fold the manipulator back from the singular straight posture. For internal singularities, the algorithm controls the manipulator with null space motion. We show that this strategy allows a manipulator to move within singular regions and back to non-singular regions, so the usable workspace is increased compared with conventional approaches. The proposed algorithm is validated in simulations and real-time control experiments.

WRENCH-CLOSURE WORKSPACE OF SIX-DOF PARALLEL MECHANISMS DRIVEN BY 7 CABLES

2005 ◽  
Vol 29 (4) ◽  
pp. 541-552 ◽  
Author(s):  
Marc Gouttefarde ◽  
Clément M. Gosselin
Keyword(s):  
Cross Sections ◽  
Degree Of Freedom ◽  
Parallel Mechanisms ◽  
Six Dof ◽  
Moving Platform ◽  
Six Degree Of Freedom

The wrench-closure workspace (WCW) of six-degree-of-freedom (DOF) parallel cable-driven mechanisms is defined as the set of poses of the moving platform of the mechanism for which any external wrench can be balanced by tension forces in the cables. This workspace is fundamental in order to analyze and design parallel cable-driven mechanisms. This paper deals with the class of six-DOF mechanisms driven by seven cables. Two theorems, which provide efficient means to test whether a given pose of the moving platform belongs to the WCW, are proposed. One of these two theorems reveals the nature of the boundary of the constant-orientation cross sections of the WCW. Moreover, some of the possible applications of these theorems are discussed and illustrated.

Design And Implementation Of A Real Time Attitude Estimation System With Low Cost Sensors

2020 ◽  
Author(s):  
Roney D. da Silva ◽  
Heloise Assis Fazzolari ◽  
Diego Paolo Ferruzzo Correa
Keyword(s):  
Embedded System ◽  
Control Systems ◽  
Attitude Determination ◽  
Least Squares Method ◽  
Complete System ◽  
Low Cost ◽  
Challenging Tasks ◽  
The Embedded System ◽  
Estimation System ◽  
Six Degree Of Freedom

Getting the attitude of drones, underwater vehicles or other six degree of freedom (DoF) devices is one of the most challenging tasks in the project of navigation control systems. For this reason, many projects use proprietary software or are limited to simulations. This work presents a complete system for attitude determination capable of provide estimated attitude and calibrated measurements using MEMS, with a low-cost and low-power microcontroller. The accelerometer and magnetometer are calibrated online on the embedded system using least squares method without any external devices. The states estimation is computed with a fast algebraic quaternion algorithm (less than 1.5s) using an additive linear Kalman Filter and model measurements.

scholarly journals A Six Degree of Freedom Epicyclic-Parallel Manipulator

2012 ◽  
Vol 4 (4) ◽  
Author(s):  
Chao Chen ◽  
Thibault Gayral ◽  
Stéphane Caro ◽  
Damien Chablat ◽  
Guillaume Moroz ◽  
...  
Keyword(s):  
Inverse Kinematics ◽  
Parallel Manipulator ◽  
Degree Of Freedom ◽  
Kinematics Analysis ◽  
End Effector ◽  
Six Dof ◽  
Six Degree Of Freedom

A new six-dof epicyclic-parallel manipulator with all actuators allocated on the ground is introduced. It is shown that the system has a considerably simple kinematics relationship, with the complete direct and inverse kinematics analysis provided. Further, the first and second links of each leg can be driven independently by two motors. The serial and parallel singularities of the system are determined, with an interesting feature of the system being that the parallel singularity is independent of the position of the end-effector. The workspace of the manipulator is also analyzed with future applications in haptics in mind.

Reduction of Instrumented Linkage Data for Simple Anatomical Joint Models

1982 ◽  
Vol 104 (1) ◽  
pp. 218-226 ◽  
Author(s):  
G. L. Kinzel
Keyword(s):  
Optimization Theory ◽  
Degree Of Freedom ◽  
Linkage Data ◽  
Joint Models ◽  
Revolute Joint ◽  
Motion Data ◽  
Technical Personnel ◽  
Six Dof ◽  
Six Degree Of Freedom ◽  
Two Bodies

When measuring the total, six degree-of-freedom (dof) motion permitted by an anatomical joint, it is convenient to attach the ends of an instrumented linkage to the two bodies meeting at the joint and to measure six independent linkage variables as the bodies move. While this method gives a complete description of the motion, it does not permit the motion to be described in a quantifiable manner that non-technical personnel understand. It is therefore often desirable to model the joint as as simple joint which permits fewer than six dof’s, e.g., as a spherical or even a revolute joint. If this is done, a decision must be made as how the six-dof data will be used to define the motion data associated with these simple models. It is the purpose of this paper to present an approach for doing this based in part on optimization theory.

On-Line Fault-Tolerant Fuzzy-Based Path Planning and Obstacles Avoidance Approach for Manipulator Robots

2018 ◽  
Vol 26 (05) ◽  
pp. 809-838 ◽  
Author(s):  
Abderraouf Maoudj ◽  
Abdelfetah Hentout ◽  
Brahim Bouzouia ◽  
Redouane Toumi
Keyword(s):  
Fault Tolerance ◽  
Path Planning ◽  
Fault Tolerant ◽  
Degree Of Freedom ◽  
Planning Approach ◽  
Industrial Manipulators ◽  
On Line ◽  
Point To Point ◽  
Six Degree Of Freedom ◽  
High Degree

Manipulator robots are widely used in many fields to replace humans in complex and risky environments. However, in some particular environments the robot is prone to failure, resulting in decreased performance. In such environments, it is extremely difficult to repair the robot which interrupts the execution process. Therefore, fault tolerance plays an important role in industrial manipulators applications. In this paper, the key problems related to fault-tolerance and path planning of manipulator robots under joints failures are handled within an on-line fault-tolerant fuzzy-logic based path planning approach for high degree-of-freedom robots. This approach provides an alternative to using mathematical models to control such robots, and improves tolerance to certain faults and mechanical failures. The controller consists of two fuzzy units (i) the first unit, Fuzzy_Path_Planner, is responsible of path planning; (ii) the second unit, Fuzzy_Obstacle_Avoidance, is conceived for obstacles avoidance. Moreover, the proposed approach is capable of repelling the manipulator away from both local minima and limit cycle problems. Finally, to validate the proposed approach and show its performances and effectiveness, different tests are carried out on two six degree-of-freedom manipulator robots (ULM and PUMA560 robots), accomplishing point-to-point tasks, with and without considering some joints failures.

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