scholarly journals Forward Kinematics Model for Evaluation of Machining Performance of Robot Type Machine Tool

2021 ◽  
Vol 15 (2) ◽  
pp. 215-223
Author(s):  
Akio Hayashi ◽  
Hiroto Tanaka ◽  
Masato Ueki ◽  
Hidetaka Yamaoka ◽  
Nobuaki Fujiki ◽  
...  
Keyword(s):  
Machine Tool ◽  
Machine Tools ◽  
Geometric Model ◽  
Forward Kinematics ◽  
Machining Accuracy ◽  
Machining Performance ◽  
Machined Surface ◽  
Kinematics Model ◽  
Tool Posture ◽  
Type Machine

Robot-type machine tools are characterized by the ability to change the tool posture and machine itself with a wider motion range than conventional machine tools. The motion of the robot machine tool is realized by simultaneous multi-axis control of link mechanisms. However, when the robot machine tool performs a general milling process, some problems that affect the machining accuracy occur. Moreover, it is difficult to identify the motion errors of each axis, which influence machining accuracy. Thus, it is difficult to adjust the servo gain and alignment error. In addition, the machining performance is unidentified because of the rigidity differences when the posture changes. In this study, the focus was on robot-type machine tools consisting of a serial and a parallel link mechanism. A geometric model is described, and the forward kinematics model is derived based on the geometric model. Machining tests were then carried out to evaluate the machining accuracy by measuring the machined surfaces and the simulated motion of the tool posture based on the proposed forward kinematics model to identify the mechanism that affects the machined surface roughness and surface waviness. As a result, it was shown that the proposed model can separate and reproduce the behavior of each axis of the machine. Finally, it was clarified that the behavior of the second axis has a great influence on the tool posture and machined surface.

Machining Performance Evaluation of Robot Type Machine Tool Based on Forward Kinematics Model

2020 ◽  
Author(s):  
Akio Hayashi ◽  
Masato Ueki ◽  
Keisuke Nagao ◽  
Hiroto Tanaka ◽  
Yoshitaka Morimoto ◽  
...  
Keyword(s):  
Machine Tools ◽  
Geometric Model ◽  
Forward Kinematics ◽  
Machining Accuracy ◽  
Machining Performance ◽  
Kinematics Model ◽  
Link Mechanism ◽  
Conventional Machine ◽  
Type Machine ◽  
Parallel Link

Abstract Robot type machine tools with parallel link mechanism are characterized by the performance to change tool posture and machine wider range than conventional machine tools. It is realized by simultaneous multi-axis control of parallel link mechanism. However, there are some problems, it is difficult to identify and adjust alignment error. In addition, the machining performance is unidentified due to the rigidity is different from conventional machine tools. In this research, a geometric model is described and the forward kinematics model is derived based on the geometric model. Then, the machining tests were carried out to evaluate the machining accuracy by measured machined surface and the simulated motion of tool cutting edge based on proposed forward kinematics model.

A Parallely Actuated Work Support Module for Reconfigurable Machining Systems

1998 ◽  
Author(s):  
Venkat Gopalakrishnan ◽  
Sridhar Kota
Keyword(s):  
Machine Tool ◽  
Machine Tools ◽  
Degrees Of Freedom ◽  
Mechanical Design ◽  
Performance Criteria ◽  
Machining Accuracy ◽  
Parallel Mechanisms ◽  
Element Analysis ◽  
Work Support ◽  
Reconfigurable Machining

Abstract In order to respond quickly to changes in market demands and the resulting product design changes, machine tool manufacturers must reduce the machine tool design lead time and machine set-up time. Reconfigurable Machine Tools (RMTs), assembled from machine modules such as spindles, slides and worktables are designed to be easily reconfigured to accommodate new machining requirements. The essential characteristics of RMTs are modularity, flexibility, convertibility and cost effectiveness. The goal of Reconfigurable Machining Systems (RMSs), composed of RMTs and other types of machines, is to provide exactly the capacity and functionality, exactly when needed. The scope of RMSs design includes mechanical hardware, control systems, process planning and tooling. One of the key challenges in the mechanical design of reconfigurable machine tools is to achieve the desired machining accuracy in all intended machine configurations. To meet this challenge we propose (a) to distribute the total number of degrees of freedom between the work-support and the tool and (b) employ parallely-actuated mechanisms for stiffness and ease of reconfigurability. In this paper we present a novel parallely-actuated work-support module as a part of an RMT. Following a brief summary of a few parallel mechanisms used in machine tool applications, this paper presents a three-degree-of-freedom work-support module designed to meet the machining requirements of specific features on a family of automotive cylinder heads. Inverse kinematics, dynamic and finite element analysis are performed to verify the performance criteria such as workspace envelope and rigidity. A prototype of the proposed module is also presented.

Dynamic optimization method with applications for machine tools based on approximation model

2017 ◽  
Vol 232 (11) ◽  
pp. 2009-2022 ◽  
Author(s):  
TJ Li ◽  
XH Ding ◽  
K Cheng ◽  
T Wu
Keyword(s):  
Machine Tool ◽  
Performance Optimization ◽  
Machine Tools ◽  
Optimization Design ◽  
Natural Frequencies ◽  
Dynamic Performance ◽  
Machining Process ◽  
Machining Accuracy ◽  
Approximation Model ◽  
Dynamic Behaviors

Natural frequencies and modal shapes of machine tools have position-dependent characteristics owing to their dynamic behaviors changing with the positions of moving parts. It is time-consuming and difficult to evaluate the dynamic behaviors of machine tools and their machining accuracy at different positions. In this paper, a Kriging approximation model coupled with finite element method is proposed to substitute the dynamic equations for obtaining the position-dependent natural frequencies of a machine tool, as well as relative positions between the tool and the workpiece during the machining process. Based on the proposed method, dynamic performance optimization design of the machine tool is conducted under the condition of minimum relative positions. Three case studies are illustrated to demonstrate the implementation of the proposed method.

Control of PLC for Paving Stock Mechanism of New-Type Machine Tool about Rapid Prototyping Manufacturing for Ceramic Parts

2010 ◽  
Vol 154-155 ◽  
pp. 1085-1090
Author(s):  
Dong Qiang Gao ◽  
Zhen Ya Tian ◽  
Fei Zhang
Keyword(s):  
Rapid Prototyping ◽  
Machine Tool ◽  
Machine Tools ◽  
Programmable Logic Controller ◽  
Programmable Logic ◽  
New Type ◽  
Type Machine ◽  
Working Principle ◽  
Rapid Prototyping Manufacturing ◽  
Automatic Manufacturing

With the development of the rapid prototyping manufacturing for ceramic parts, it is possible to shorten the manufacturing period of ceramic parts and improve the enterprise’s productivity efficiency. The development situation of the machine tools about rapid prototyping manufacturing for ceramic parts was introduced. A new-style device about rapid prototyping manufacturing for ceramic parts, which is based on the technology of laminated coalition and rapid concrete prototyping for ceramic parts, is designed. The basic constitutions, technical processing and working principle of the paving stock mechanism of the device have also been described. The PLC (programmable logic controller) is applied in the paving stock mechanism for controlling and runs well, which meets the requirements of automatic manufacturing for ceramic parts and improves the efficiency.

An investigation on modeling and compensation of synthetic geometric errors on large machine tools based on moving least squares method

2016 ◽  
Vol 232 (3) ◽  
pp. 412-427 ◽  
Author(s):  
Zihan Li ◽  
Wenlong Feng ◽  
Jianguo Yang ◽  
Yiqiao Huang
Keyword(s):  
Machine Tool ◽  
Least Squares ◽  
Error Compensation ◽  
Machine Tools ◽  
Geometric Error ◽  
Moving Least Squares ◽  
Geometric Errors ◽  
Position Accuracy ◽  
Type Machine ◽  
Large Machine

This article intends to provide an efficient modeling and compensation method for the synthetic geometric errors of large machine tools. Analytical and experimental examinations were carried out on a large gantry-type machine tool to study the spatial geometric error distribution within the machine workspace. The result shows that the position accuracy of the tool-tip is affected by all the translational axes synchronously, and the position error curve shape is non-linear and irregular. Moreover, the angular error combined with Abbe’s offset during the motion of a translational axis would cause Abbe’s error and generate significant influence on the spatial positioning accuracy. In order to identify the combined effect of the individual error component on the tool-tip position accuracy, a synthetic geometric error model is established for the gantry-type machine tool. Also, an automatic modeling algorithm is proposed to approximate the geometric error parameters based on moving least squares in combination with Chebyshev polynomials, and it could approximate the irregular geometric error curves with high-order continuity and consistency with a low-order basis function. Then, to implement real-time error compensation on large machine tools, an intelligent compensation system is developed based on the fast Ethernet data interaction technique and external machine origin shift, and experiment validations on the gantry-type machine tool showed that the position accuracy could be improved by 90% and the machining precision could be improved by 85% after error compensation.

Research of the Technological Parameters Influencing on the Surface Quality of Micro Complex Surface

2005 ◽  
Vol 291-292 ◽  
pp. 513-518 ◽  
Author(s):  
Ming Jun Chen ◽  
Ying Chun Liang ◽  
Ya Zhou Sun ◽  
W.X. Guo ◽  
Wen Jun Zong
Keyword(s):  
Machine Tool ◽  
Three Dimensional ◽  
Complex Surface ◽  
Cutting Parameters ◽  
Numerical Control ◽  
Tool Geometry ◽  
Machining Accuracy ◽  
Technological Parameters ◽  
Machined Surface ◽  
Machining Errors

In order to machine complex free surface parts, a micro NC (numerical control) three-dimensional machine tool is developed, integrated the PMAC control. Based on this NC machine tool, the influencing of the technological and tool’s parameters on machining accuracy of micro complex surface parts are analyzed, and the cause to lead to the machining errors is explained. Therefore, the cutting parameters and tool geometry parameters to machine micro complex surface, such as the human’s face, can be selected optimally. Finally, the micro complex human’s face is machined on this developed micro machine tool under optimal parameters. The experimental results show that the machined surface is smooth and continuous. The machined quality is satisfied.

To Identify Key Geometric Errors of 3-Axis NC Machine Tool by Machining Accuracy Failure Mode Analysis

2019 ◽  
Author(s):  
Baobao Qi ◽  
Qiang Cheng ◽  
Zhifeng Liu ◽  
Dongyang Sun
Keyword(s):  
Machine Tool ◽  
Failure Mode ◽  
Failure Modes ◽  
Geometric Error ◽  
Mode Analysis ◽  
Major Influence ◽  
Work Piece ◽  
Machining Accuracy ◽  
Geometric Errors ◽  
Machined Surface

Abstract Machine tools usually cut two or more surfaces after the work piece clamped on work table. In order to improve the machining accuracy and optimize accuracy design, it is hoped that the geometric errors that influence the accuracy of machined surface prominently can be known beforehand, so the adjustment will be carried out with a definite objective rather than without any clue. Because the machining accuracy of each direction in 3-D space is different value, in this paper, machining accuracy failure mode was defined as the various combination of the machining accuracy of each direction according to whether it is up to the reserved objective value or not. A three-axis machine tool was selected as an example and there were 7 machining accuracy failure modes for it. Based on the generalized correlation analysis, the correlation relationships between 7 machining accuracy failure modes were analyzed, and the main failure modes that affect the machining accuracy of work piece to be machined were identified. For each machining accuracy failure mode, key geometric error that had major influence on it was identified based on sensitivity analysis. Finally, four stepped work pieces were milled by a 3-axis machine tool to illustrate the analytical method proposed in this study.

Mini Special Issue on Machining Control and Process Monitoring

2014 ◽  
Vol 8 (6) ◽  
pp. 791-791
Author(s):  
Tojiro Aoyama
Keyword(s):  
Machine Tool ◽  
Process Monitoring ◽  
Machine Tools ◽  
Cutting Tools ◽  
Machining Process ◽  
Machining Accuracy ◽  
Special Issue ◽  
Practical Proposal ◽  
Machining Control ◽  
Novel Approaches

Control and process monitoring are key technologies supporting high machining accuracy and efficiency. This special issue features six papers taking novel approaches to controlling machine and cutting tools and monitoring the machining process. The motion control of machine tools and cutting tools are introduced. A new challenge for monitoring the machining process by referring to NC control servo signals implements a practical proposal. The precise identification of friction at driving elements of machine tool components is an important factor in improving machine tool control motion accuracy. I would like to express my sincere appreciation to the authors and reviewers whose invaluable efforts have helped make the publication of this manuscript possible.

Research on the Kinematics of Line Heating Robot Based on SVM

2014 ◽  
Vol 668-669 ◽  
pp. 361-365
Author(s):  
Yan Li ◽  
You Li Chen
Keyword(s):  
Inverse Kinematics ◽  
Geometric Model ◽  
Forward Kinematics ◽  
Robot Kinematics ◽  
Support Vector ◽  
Line Heating ◽  
Kinematics Model ◽  
Heating Plate ◽  
Kinematics Modeling ◽  
Complex Trajectory

The paper mainly analyzed the robot kinematics of the line heating plate. In order to realize the moving of complex trajectory for the robot, a forward kinematics modeling and the simulation of inverse kinematics are carried out. Firstly, with the D-H modeling method, the line heating plate robot forward kinematics equations and the spatial geometric model of the manipulator are set up, then multi-input multi-output systems based on support vector machines algorithm is used to establish the inverse kinematics model for the robot . At last, the simulations of tracing complex trajectory with the inverse kinematics model are carried out, and the results show that the model derived by SVM can trace the trajectory very well.

Measurement and analysis for frequency domain error of ultra-precision spindle in a flycutting machine tool

2016 ◽  
Vol 232 (9) ◽  
pp. 1501-1507 ◽  
Author(s):  
Guoda Chen ◽  
Yazhou Sun ◽  
Chenhui An ◽  
Feihu Zhang ◽  
Zhiji Sun ◽  
...  
Keyword(s):  
Machine Tool ◽  
Frequency Domain ◽  
Frequency Domain Analysis ◽  
Frequency Characteristics ◽  
Machining Process ◽  
Machining Accuracy ◽  
Machined Surface ◽  
Ultra Precision ◽  
Machining Process Planning ◽  
Aerostatic Spindle

The ultra-precision spindle is the key component of ultra-precision machine tool, which largely influences the machining accuracy. Its frequency characteristics mainly affect the frequency domain error of the machined surface. In this article, the error measurement setup for the ultra-precision aerostatic spindle in a flycutting machine tool is established. The dynamic and multi-direction errors of the spindle are real-time measured under different rotation speeds. Then, frequency domain analysis is carried out to obtain its regularity characteristics based on the measurement result. Through the analysis, the main synchronous and asynchronous errors with relatively large amplitude of the spindle errors are found, and the amplitude change law of these main spindle errors is obtained. Besides, the cause of the main synchronous and asynchronous errors is also analyzed and indicated. This study deepens the understanding of ultra-precision spindle dynamic characteristics and plays the important role in the spindle frequency domain errors’ control, machining process planning, frequency characteristics analysis and oriented control of the machined surface errors.

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