Graphical interface development for the position control of a 3RRR planar parallel manipulator

This paper presents the development of a graphical interface implemented in a 3-RRR planar parallel manipulator. The graphical interface allows the control, in open loop, of the position of the manipulator, allowing to locate in the plane the end actuator and define its pose. The graphical interface allows the visualization of variables such as angular position, torque, voltage of the servomotors that drive the input links. The theoretical and real comparison of the angular displacement and the torque in the motors during the chosen path is shown, obtaining very close results between both.This paper presents the development of a graphical interface implemented in a 3-RRR planar parallel manipulator. The graphical interface allows the control, in open loop, of the position of the manipulator, allowing to locate in the plane the end actuator and define its pose. The graphical interface allows the visualization of variables such as angular position, torque, voltage of the servomotors that drive the input links. The theoretical and real comparison of the angular displacement and the torque in the motors during the chosen path is shown, obtaining very close results between both

Graphical interface development for the position control of a 3RRR planar parallel manipulator

This paper presents the development of a graphical interface implemented in a 3-RRR planar parallel manipulator. The graphical interface allows the control, in open loop, of the position of the manipulator, allowing to locate in the plane the end actuator and define its pose. The graphical interface allows the visualization of variables such as angular position, torque, voltage of the servomotors that drive the input links. The theoretical and real comparison of the angular displacement and the torque in the motors during the chosen path is shown, obtaining very close results between both.This paper presents the development of a graphical interface implemented in a 3-RRR planar parallel manipulator. The graphical interface allows the control, in open loop, of the position of the manipulator, allowing to locate in the plane the end actuator and define its pose. The graphical interface allows the visualization of variables such as angular position, torque, voltage of the servomotors that drive the input links. The theoretical and real comparison of the angular displacement and the torque in the motors during the chosen path is shown, obtaining very close results between both

Graphical interface development for the position control of a 3RRR planar parallel manipulator

This paper presents the development of a graphical interface implemented in a 3-RRR planar parallel manipulator. The graphical interface allows the control, in open loop, of the position of the manipulator, allowing to locate in the plane the end actuator and define its pose. The graphical interface allows the visualization of variables such as angular position, torque, voltage of the servomotors that drive the input links. The theoretical and real comparison of the angular displacement and the torque in the motors during the chosen path is shown, obtaining very close results between both.This paper presents the development of a graphical interface implemented in a 3-RRR planar parallel manipulator. The graphical interface allows the control, in open loop, of the position of the manipulator, allowing to locate in the plane the end actuator and define its pose. The graphical interface allows the visualization of variables such as angular position, torque, voltage of the servomotors that drive the input links. The theoretical and real comparison of the angular displacement and the torque in the motors during the chosen path is shown, obtaining very close results between both

Parallel Manipulators

In recent years, parallel kinematics mechanisms have attracted a lot of attention from the academic and industrial communities due to potential applications not only as robot manipulators but also as machine tools. Generally, the criteria used to compare the performance of traditional serial robots and parallel robots are the workspace, the ratio between the payload and the robot mass, accuracy, and dynamic behaviour. In addition to the reduced coupling effect between joints, parallel robots bring the benefits of much higher payload-robot mass ratios, superior accuracy and greater stiffness; qualities which lead to better dynamic performance. The main drawback with parallel robots is the relatively small workspace. A great deal of research on parallel robots has been carried out worldwide, and a large number of parallel mechanism systems have been built for various applications, such as remote handling, machine tools, medical robots, simulators, micro-robots, and humanoid robots. This book opens a window to exceptional research and development work on parallel mechanisms contributed by authors from around the world. Through this window the reader can get a good view of current parallel robot research and applications

A Branch and Prune Algorithm for the Computation of Generalized Aspects of Parallel Robots

International audienceParallel robots enjoy enhanced mechanical characteristics that have to be contrasted with a more complicated design. In particular, they often have parallel singularities at some poses, and the robots may become uncontrollable, and could even be damaged, in such configurations. The computation of the connected components in the set of nonsingular reachable configurations, called generalized aspects, is therefore a key issue in their design. This paper introduces a new method, based on numerical constraint programming, to compute a certified enclosure of the generalized aspects. Though this method does not allow counting their number rigorously, it constructs inner approximations of the nonsingular workspace that allow commanding parallel robots safely. It also provides a lower-bound on the exact number of generalized aspects. It is moreover the first general method able to handle any parallel robot in theory, though its computational complexity currently restricts its usage to robots with three degrees of freedom. Finally, the contraint programming paradigm it relies on makes it possible to consider various additional constraints (e.g., collision avoidance), making it suitable for practical considerations

Neuartige Drehgelenke für reibungsarme Mechanismen : Auslegungskriterien und Berechnungsmethoden

In many branches of technology is a need for mechanisms with minimum friction and minimum bearing play. Such mechanisms are neither feasible with conventional hinges nor with hinges from the micro- and nanopositioning. This thesis proposes novel hinges in order to bridge the gap between the precision of micropositioning and the workspace of applications in manufacturing. The proposed implementations are flexure hinges for large displacements and dry slide bearings with friction reduction

Neuartige Drehgelenke für reibungsarme Mechanismen : Auslegungskriterien und Berechnungsmethoden

In vielen Bereichen der Technik, insbesondere der Mikrofertigung, gibt es einen Bedarf an spiel- und reibungsarmen Mechanismen. Solche Mechanismen können bisher weder mit konventionellen Gelenken noch mit Gelenken der Mikro- oder Nanopositionierung erreicht werden. Die vorliegende Arbeit setzt an diesen Defiziten an und entwickelt neue Lösungsansätze. Zu den erarbeiteten Vorschlägen gehören Festkörpergelenke für große Ausschläge und Trockengleitlager mit Reibwertglättung

Time Localization of Abrupt Changes in Cutting Process using Hilbert Huang Transform

Cutting process is extremely dynamical process influenced by different phenomena such as chip formation, dynamical responses and condition of machining system elements. Different phenomena in cutting zone have signatures in different frequency bands in signal acquired during process monitoring. The time localization of signal’s frequency content is very important. An emerging technique for simultaneous analysis of the signal in time and frequency domain that can be used for time localization of frequency is Hilbert Huang Transform (HHT). It is based on empirical mode decomposition (EMD) of the signal into intrinsic mode functions (IMFs) as simple oscillatory modes. IMFs obtained using EMD can be processed using Hilbert Transform and instantaneous frequency of the signal can be computed. This paper gives a methodology for time localization of cutting process stop during intermittent turning. Cutting process stop leads to abrupt changes in acquired signal correlated to certain frequency band. The frequency band related to abrupt changes is localized in time using HHT. The potentials and limitations of HHT application in machining process monitoring are shown

Friction Force Microscopy of Deep Drawing Made Surfaces

Aim of this paper is to contribute to micro-tribology understanding and friction in micro-scale interpretation in case of metal beverage production, particularly the deep drawing process of cans. In order to bridging the gap between engineering and trial-and-error principles, an experimental AFM-based micro-tribological approach is adopted. For that purpose, the can’s surfaces are imaged with atomic force microscopy (AFM) and the frictional force signal is measured with frictional force microscopy (FFM). In both techniques, the sample surface is scanned with a stylus attached to a cantilever. Vertical motion of the cantilever is recorded in AFM and horizontal motion is recorded in FFM. The presented work evaluates friction over a micro-scale on various samples gathered from cylindrical, bottom and round parts of cans, made of same the material but with different deep drawing process parameters. The main idea is to link the experimental observation with the manufacturing process. Results presented here can advance the knowledge in order to comprehend the tribological phenomena at the contact scales, too small for conventional tribology

Towards a Conceptual Design of an Intelligent Material Transport Based on Machine Learning and Axiomatic Design Theory

Reliable and efficient material transport is one of the basic requirements that affect productivity in sheet metal industry. This paper presents a methodology for conceptual design of intelligent material transport using mobile robot, based on axiomatic design theory, graph theory and artificial intelligence. Developed control algorithm was implemented and tested on the mobile robot system Khepera II within the laboratory model of manufacturing environment. Matlab© software package was used for manufacturing process simulation, implementation of search algorithms and neural network training. Experimental results clearly show that intelligent mobile robot can learn and predict optimal material transport flows thanks to the use of artificial neural networks. Achieved positioning error of mobile robot indicates that conceptual design approach can be used for material transport and handling tasks in intelligent manufacturing systems