Study on Improving Accuracy in Robotic Milling of Aluminum Alloy

2018 ◽  
Author(s):  
Shaochun Sui ◽  
Kai Guo ◽  
Jie Sun ◽  
Yiran Zang
Keyword(s):  
Aluminum Alloy ◽  
Industrial Robot ◽  
Vibration Signal ◽  
Industrial Robots ◽  
Machining Process ◽  
Cnc Machine ◽  
Machined Surface ◽  
Improving Accuracy ◽  
High Level ◽  
Monolithic Components

Nowadays, the application of using industrial robots in manufacture is a diminutive due to its own low rigidity and low stiffness. This leads to high level of vibrations that limits the quality and the precision of the workpiece. So they are usually used for welding, grinding and paint shop. However, the potential of industrial robot applications in machining has be realized. The volume of monolithic components is large and there are many issues in machining process such as geometric tolerance and quality of machined surface. In such cases the traditional CNC machine is replaced by industrial robots, which will reduce the production cost, reduce labor and increase the efficiency. In this paper, the milling experiment of 7050-T7451 aeronautical aluminum alloy was carried out by using industrial robot KR210 R2700. In addition, the experiment was employed to study the influence of milling speed, feed-rate, cutting depth and cutting width on vibrations, surface roughness was also measured to evaluate the machining quality. Besides, the axis of angle was changed which led to the different industrial robot’s postures. The vibration signal of different postures was acquired, which was used to analysis the optimal workspace of industrial robot. The best process parameters were obtained, which will play a guiding significance on the actual production.

RESEARCH ON CONDITION MONITORING OF SPEED REDUCER OF INDUSTRIAL ROBOT WITH ACOUSTIC EMISSION

2016 ◽  
Vol 40 (5) ◽  
pp. 1041-1049 ◽  
Author(s):  
Xiaoqin Liu ◽  
Xing Wu ◽  
Chang Liu ◽  
Tao Liu
Keyword(s):  
Acoustic Emission ◽  
Industrial Robot ◽  
Vibration Signal ◽  
Rolling Bearing ◽  
Transmission System ◽  
Industrial Robots ◽  
Inspection Method ◽  
Term Operation ◽  
Operation Speed ◽  
Speed Reducer

Articulated industrial robots are widely used for factory automation, e.g., the car manufacture industry. As other machines, the transmission system of industrial robot is prone to fail after long term operation. Speed reducer is the key component of the transmission system, and it is important to detect its incipient faults to avoid breaking down. However, until now, few techniques have been proposed to diagnose the reducer without disassembly. Our research on monitoring and diagnosing the speed reducer of industrial robot is reported in this paper. The technique combines inspection method of acoustic emission and signal processing of vibration signal. The characteristics of acoustic emission signal and their connections with mechanical parts of robot reducer have been studied. A defect in the rolling bearing was detected on a welding robot by this technique and confirmed in disassembly.

scholarly journals Wireless Fault Detection System for an Industrial Robot Based on Statistical Control Chart

2017 ◽  
Vol 7 (6) ◽  
pp. 3421
Author(s):  
Alaa Abdulhady Jaber ◽  
Robert Bicker
Keyword(s):  
Fault Detection ◽  
Control Chart ◽  
Production Systems ◽  
Detection System ◽  
Industrial Robot ◽  
Vibration Signal ◽  
Cost Effective ◽  
Base Station ◽  
Industrial Robots ◽  
Statistical Control

Industrial robots are now commonly used in production systems to improve productivity, quality and safety in manufacturing processes. Recent developments involve using robots cooperatively with production line operatives. Regardless of application, there are significant implications for operator safety in the event of a robot malfunction or failure, and the consequent downtime has a significant impact on productivity in manufacturing. Machine healthy monitoring is a type of maintenance inspection technique by which an operational asset is monitored and the data obtained is analysed to detect signs of degradation and thus reducing the maintenance costs. Developments in electronics and computing have opened new horizons in the area of condition monitoring. The aim of using wireless electronic systems is to allow data analysis to be carried out locally at field level and transmitting the results wirelessly to the base station, which as a result will help to overcome the need for wiring and provides an easy and cost-effective sensing technique to detect faults in machines. So, the main focuses of this research is to develop an online and wireless fault detection system for an industrial robot based on statistical control chart approach. An experimental investigation was accomplished using the PUMA 560 robot and vibration signal capturing was adopted, as it responds immediately to manifest itself if any change is appeared in the monitored machine, to extract features related to the robot health conditions. The results indicate the successful detection of faults at the early stages using the key extracted parameters.

Machining with Image Recognition Using Industrial Robot

2012 ◽  
Vol 186 ◽  
pp. 50-57 ◽  
Author(s):  
Tadeusz Mikolajczyk ◽  
Pawel Wasiak
Keyword(s):  
Image Recognition ◽  
Industrial Robot ◽  
Surface Grinding ◽  
Machining Process ◽  
Robot System ◽  
Machined Surface ◽  
Usb Camera

Paper describes the robot equipped with USB camera for capture view of machined objects and tools holder mounted to robots wrist. Showed ideas of using view of machined surface to programming the machining process as art milling or surface grinding. Special pc control of industrial robot system was used.

scholarly journals Modeling and Identification of an Industrial Robot with a Selective Modal Approach

2020 ◽  
Vol 10 (13) ◽  
pp. 4619 ◽  
Author(s):  
Matteo Bottin ◽  
Silvio Cocuzza ◽  
Nicola Comand ◽  
Alberto Doria
Keyword(s):  
Dynamic Model ◽  
Material Removal ◽  
Industrial Robot ◽  
Joint Stiffness ◽  
Industrial Applications ◽  
Industrial Robots ◽  
Robotic Assembly ◽  
Machined Surface ◽  
Modal Approach ◽  
Removal Processes

The stiffness properties of industrial robots are very important for many industrial applications, such as automatic robotic assembly and material removal processes (e.g., machining and deburring). On the one hand, in robotic assembly, joint compliance can be useful for compensating dimensional errors in the parts to be assembled; on the other hand, in material removal processes, a high Cartesian stiffness of the end-effector is required. Moreover, low frequency chatter vibrations can be induced when low-stiffness robots are used, with an impairment in the quality of the machined surface. In this paper, a compliant joint dynamic model of an industrial robot has been developed, in which joint stiffness has been experimentally identified using a modal approach. First, a novel method to select the test configurations has been developed, so that in each configuration the mode of vibration that chiefly involves only one joint is excited. Then, experimental tests are carried out in the selected configurations in order to identify joint stiffness. Finally, the developed dynamic model of the robot is used to predict the variation of the natural frequencies in the workspace.

scholarly journals Analysis of the Compliance Properties of an Industrial Robot with the Mozzi Axis Approach

Robotics ◽  
2019 ◽  
Vol 8 (3) ◽  
pp. 80 ◽  
Author(s):  
Doria ◽  
Cocuzza ◽  
Comand ◽  
Bottin ◽  
Rossi
Keyword(s):  
Industrial Robot ◽  
Industrial Robots ◽  
Robotic Assembly ◽  
Robot Arm ◽  
Machined Surface ◽  
End Effector ◽  
Chatter Vibrations ◽  
Modes Of Vibration ◽  
Machining Robot ◽  
Robot Performance

In robotic processes, the compliance of the robot arm plays a very important role. In some conditions, for example, in robotic assembly, robot arm compliance can compensate for small position and orientation errors of the end-effector. In other processes, like machining, robot compliance may generate chatter vibrations with an impairment in the quality of the machined surface. In industrial robots, the compliance of the end-effector is chiefly due to joint compliances. In this paper, joint compliances of a serial six-joint industrial robot are identified with a novel modal method making use of specific modes of vibration dominated by the compliance of only one joint. Then, in order to represent the effect of the identified compliances on robot performance in an intuitive and geometric way, a novel kinematic method based on the concept of “Mozzi axis” of the end-effector is presented and discussed.

Low Frequency Vibration Consideration in Tool-Path Computation of Two-Link Serial Manipulator for Improved Accuracy

2014 ◽  
Author(s):  
Denis Juschanin ◽  
Fisseha M. Alemayehu ◽  
Stephen Ekwaro-Osire
Keyword(s):  
Mode Coupling ◽  
Tool Path ◽  
Industrial Robot ◽  
Research Question ◽  
Low Frequency ◽  
Industrial Robots ◽  
Machining Process ◽  
Future Research ◽  
Low Frequency Vibration ◽  
Path Computation

Industrial robots are flexible and cost-efficient tools for a multitude of applications such as, polishing, grinding, deburring, and welding. However, their utilization in machining tasks is currently limited due to insufficient position accuracy. This study aims to answer the research question: ‘Does including low frequency vibrations (mode coupling chatter) in tool path computation improve accuracy?’ For this purpose, the current paper focuses on setting-up a robust and flexible simulation framework. The framework implements a predictive cutting force method into a multibody dynamic (MBD) model of an industrial robot. The framework is structured in an extendable fashion for future research tasks. Future work will include mode coupling chatter into the MBD model to help mitigate the effects of chatter in robotic machining process, which in turn will increase tool-path accuracy.

scholarly journals Industrial Robot Positioning Performance Measured on Inclined and Parallel Planes by Double Ballbar

2021 ◽  
Vol 11 (4) ◽  
pp. 1777
Author(s):  
Ivan Kuric ◽  
Vladimír Tlach ◽  
Milan Sága ◽  
Miroslav Císar ◽  
Ivan Zajačko
Keyword(s):  
Machine Tools ◽  
Industrial Robot ◽  
Industrial Robots ◽  
Cnc Machine Tools ◽  
Circular Path ◽  
Robot Arm ◽  
Cnc Machine ◽  
Positional Analysis ◽  
Polar Graph ◽  
Robot Positioning

Renishaw Ballbar QC20–W is primarily intended for diagnostics of CNC machine tools, but it is also used in connection with industrial robots. In the case of standard measurement, when the measuring plane is parallel to the robot base, not all robot joints move. The purpose of the experiments of the present article was to verify the hypothesis of the motion of all the robot joints when the desired circular path is placed on an inclined plane. In the first part of the conducted experiments is established hypothesis is confirmed, through positional analysis on a simulation model of the robot. They are then carried out practical measurements being evaluated the influence of individual robot joints to deform the circular path, shown as a polar graph. As a result, it is found that in the case of the robot used, changing the configuration of the robot arm has the greatest effect on changing the shape of the polar graph.

Multidisciplinary Design Optimization of Modular Industrial Robots by Utilizing High Level CAD Templates

2012 ◽  
Vol 134 (12) ◽  
Author(s):  
Mehdi Tarkian ◽  
Johan Persson ◽  
Johan Ölvander ◽  
Xiaolong Feng
Keyword(s):  
Design Optimization ◽  
Computer Aided Design ◽  
Multidisciplinary Design Optimization ◽  
Industrial Robot ◽  
Geometric Model ◽  
Industrial Robots ◽  
Multidisciplinary Design ◽  
Strength Analysis ◽  
High Level ◽  
Aided Design

This paper presents a multidisciplinary design optimization (MDO) framework for automated design of a modular industrial robot. The developed design framework seamlessly integrates high level computer aided design (CAD) templates (HLCt) and physics based high fidelity models for automated geometry manipulation, dynamic simulation, and structural strength analysis. In the developed framework, methods such as surrogate models and multilevel optimization are employed in order to speed up the design optimization process. This work demonstrates how a parametric geometric model, based on the concept of HLCt, enables a multidisciplinary framework for multi-objective optimization of a modular industrial robot, which constitutes an example of a complex heterogeneous system.

Performance Criteria to Evaluate a Kinematically Redundant Robotic Cell for Machining Tasks

2012 ◽  
Vol 162 ◽  
pp. 413-422 ◽  
Author(s):  
Kévin Subrin ◽  
Laurent Sabourin ◽  
Grigore Gogu ◽  
Youcef Mezouar
Keyword(s):  
High Speed ◽  
Dynamic Capabilities ◽  
Industrial Robot ◽  
Kinematic Model ◽  
Geometrical Model ◽  
Industrial Robots ◽  
Machining Process ◽  
Performance Criteria ◽  
Robotic Cell ◽  
Speed Accuracy

Machine tools and robots have both evolved fundamentally and we can now question the abilities of new industrial robots concerning accurate task realization under high constraints. Requirements in terms of kinematic and dynamic capabilities in High Speed Machining (HSM) are increasingly demanding. To face the challenge of performance improvement, parallel and hybrid robotic architectures have emerged and a new generation of industrial serial robots with the ability to perform machining tasks has been designed. In this paper, we propose to evaluate the performance criteria of an industrial robot included in a kinematically redundant robotic cell dedicated to a machining task. Firstly, we present the constraints of the machining process (speed, accuracy etc.). We then detail the direct geometrical model and the kinematic model of a robot with closed chain in the arm and we propose a procedure for managing kinematic redundancy whilst integrating various criteria. Finally, we present the evolution of the criteria for a given trajectory in order to define the best location for a rotary table and to analyze the manipulators stiffness.

scholarly journals Expert Refined Topic Models to Edit Topic Clusters in Image Analysis Applied to Welding Engineering

Informatics ◽  
2020 ◽  
Vol 7 (3) ◽  
pp. 21
Author(s):  
Theodore T. Allen ◽  
Hui Xiong ◽  
Shih-Hsien Tseng
Keyword(s):  
Image Analysis ◽  
Aluminum Alloy ◽  
Gibbs Sampler ◽  
Inert Gas ◽  
Subject Matter Experts ◽  
Numerical Examples ◽  
Level Data ◽  
Efficient Processing ◽  
Improving Accuracy ◽  
High Level

This paper proposes a new method to generate edited topics or clusters to analyze images for prioritizing quality issues. The approach is associated with a new way for subject matter experts to edit the cluster definitions by “zapping” or “boosting” pixels. We refer to the information entered by users or experts as “high-level” data and we are apparently the first to allow in our model for the possibility of errors coming from the experts. The collapsed Gibbs sampler is proposed that permits efficient processing for datasets involving tens of thousands of records. Numerical examples illustrate the benefits of the high-level data related to improving accuracy measured by Kullback–Leibler (KL) distance. The numerical examples include a Tungsten inert gas example from the literature. In addition, a novel laser aluminum alloy image application illustrates the assignment of welds to groups that correspond to part conformance standards.

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