DNC Method for Flatness Reduction by Machine Tool Error Compensation in Planning Processes

2006 ◽  
Author(s):  
P. Franco ◽  
M. Estrems ◽  
F. Faura
Keyword(s):  
Machine Tool ◽  
Error Compensation ◽  
Cutting Tool ◽  
Milling Process ◽  
Numerical Control ◽  
Cnc Milling ◽  
Metrological Analysis ◽  
Workpiece Material ◽  
Technical Specifications ◽  
Mechanical Components

Milling is a widely used manufacturing process with the main purpose of generating high precision mechanical components of shapes and sizes given by the numerical control programmed cutting tool trajectory. These mechanical components frequently needs the application of milling operations in order to satisfy the technical specifications that corresponds to their dimensional, geometrical and surface quality requirements. For that reason, the effects of different factors such as cutting tool dynamics, fixturing system design, workpiece material behaviour and applied cutting forces on the desired dimensional precision must be studied, as well as cutting tool and machine tool performance. In this work, the relation between machine tool inaccuracies and geometrical tolerances is analyzed, and a methodology is proposed for improving flatness in planing operations by the correction of imperfections detected in cutting tool displacement according to machine tool axis. These machine tool error correction methodology could be implemented in the current CAD/CAM/CAPP techniques as a means of increasing the milling process performance by identification and correction of CNC milling machine imperfections. The deviations in machine tool displacement during cutting process are identified by metrological analysis, and a modified trajectory for cutting tool is defined by direct numerical control (DNC) from systematic error compensation in machine tool.

Error correction technique for numerical control machine tools based on the simplex method

2021 ◽  
pp. 095440542110281
Author(s):  
Hongwei Liu ◽  
Rui Yang ◽  
Pingjiang Wang ◽  
Jihong Chen ◽  
Hua Xiang
Keyword(s):  
Machine Tool ◽  
Error Compensation ◽  
Simplex Method ◽  
Tool Path ◽  
Repeated Measurements ◽  
Numerical Control ◽  
Machining Accuracy ◽  
Correction Technique ◽  
Fluctuation Range ◽  
Nc Machine

The objective of this research is to develop a novel correction mechanism to reduce the fluctuation range of tools in numerical control (NC) machining. Error compensation is an effective method to improve the machining accuracy of a machine tool. If the difference between two adjacent compensation data is too large, the fluctuation range of the tool will increase, which will seriously affect the surface quality of the machined parts in mechanical machining. The methodology used in compensation data processing is a simplex method of linear programming. This method reduces the fluctuation range of the tool and optimizes the tool path. The important aspect of software error compensation is to modify the initial compensation data by using an iterative method, and then the corrected tool path data are converted into actual compensated NC codes by using a postprocessor, which is implemented on the compensation module to ensure a smooth running path of the tool. The generated, calibrated, and amended NC codes were immediately fed to the machine tool controller. This technique was verified by using repeated measurements. The results of the experiments demonstrate efficient compensation and significant improvement in the machining accuracy of the NC machine tool.

scholarly journals A Non-Delay Error Compensation Method for Dual-Driving Gantry-Type Machine Tool

Processes ◽  
2020 ◽  
Vol 8 (7) ◽  
pp. 748
Author(s):  
Qi Liu ◽  
Hong Lu ◽  
Xinbao Zhang ◽  
Yu Qiao ◽  
Qian Cheng ◽  
...  
Keyword(s):  
Machine Tool ◽  
Error Compensation ◽  
Prediction Method ◽  
Compensation Method ◽  
Industrial Robots ◽  
Numerical Control ◽  
Heavy Duty ◽  
Positioning Errors ◽  
Compensation Methods ◽  
Type Machine

The drive at the center of gravity (DCG) principle has been adopted in computer numerical control (CNC) machines and industrial robots that require heavy-duty and quick feeds. Using this principle requires accurate corrections of positioning errors. Conventional error compensation methods may cause vibrations and unstable control performances due to the delay between compensation and motor motion. This paper proposes a new method to reduce the positioning errors of the dual-driving gantry-type machine tool (DDGTMT), namely, a typical DCG-principle-based machine tool. An error prediction method is proposed to characterize errors online. An algorithm is proposed to quickly and accurately compensate the errors of the DDGTMT. Experiment results verify that the non-delay error compensation method proposed in this paper can effectively improve the accuracy of the DDGTMT.

The Construction of the Management System of CNC Milling Parameters

2012 ◽  
Vol 220-223 ◽  
pp. 385-388
Author(s):  
An Jiang Cai ◽  
Yan Jun Guo ◽  
Shi Hong Guo ◽  
Ming Wei Ding
Keyword(s):  
Management System ◽  
Aircraft Engine ◽  
Milling Process ◽  
Numerical Control ◽  
Machining Parameters ◽  
Cnc Milling ◽  
Information Efficiency ◽  
Manufacturing Enterprises ◽  
Milling Parameters ◽  
Machinery Manufacturing

CNC Milling Process for the complex characteristics, in order to solve how to quickly and effectively to provide a reasonable and optimal machining parameters of CNC milling process for technologist. The paper takes horizontal machining center DMC60H as a test platform and technological data of shell aluminum alloy hydraulic aircraft engine parts as a study. the paper establish management system of CNC milling parameters which was suitable for machinery manufacturing enterprises. The results showed that: The established parameters of CNC milling system can be better management of various CNC milling technology to effectively manage information and improve the CNC milling process information efficiency, has certain promotion effect to the production of the numerical control milling processing and the development of the manufacturing enterprises.

scholarly journals Iterative learning contouring controller based on trajectory generation with linearly interpolated contour error estimation and Bézier reposition trajectory for computerized numerical control machine tool feed drive systems

2019 ◽  
Vol 11 (8) ◽  
pp. 168781401986810
Author(s):  
Yogi Muldani Hendrawan ◽  
Kenneth Renny Simba ◽  
Naoki Uchiyama
Keyword(s):  
Error Compensation ◽  
Iterative Learning ◽  
Numerical Control ◽  
Contour Error ◽  
Reference Trajectory ◽  
Control Machine Tool ◽  
Mechatronic Systems ◽  
Computerized Numerical Control ◽  
Mechanical Components ◽  
Control Machine

In industrial applications, highly accurate mechanical components are generally required to produce advanced mechanical and mechatronic systems. In machining mechanical components, contour error represents the product shape quality directly, and therefore it must be considered in controller design. Although most existing contouring controllers are based on feedback control and estimated contour error, it is generally difficult to replace the feedback controller in commercial computerized numerical control machines. This article proposes an embedded iterative learning contouring controller by considering the linearly interpolated contour error compensation and Bézier reposition trajectory, which can be applied in computerized numerical control machines currently in use without any modification of their original feedback controllers. While the linearly interpolated contour error compensation enhances tracking performance by compensating the reference input with an actual value, the Bézier reposition trajectory enables smooth velocity transitions between discrete points in the reference trajectory. For performance analysis, the proposed controller was implemented in a commercial three-axis computerized numerical control machine and several experiments were conducted based on typical three-dimensional sharp-corner and half-circular trajectories. Experimental results showed that the proposed controller could reduce the maximum and mean contour errors by 45.11% and 54.48% on average, compared to embedded iterative learning contouring controller with estimated contour error. By comparing to embedded iterative learning contouring controller with linearly interpolated contour error compensation, the maximum and mean contour errors are reduced to 20.54% and 26.92%, respectively.

Geometric Error Compensation Methods of Numerical Control Machine Tool

2012 ◽  
Vol 426 ◽  
pp. 239-242
Author(s):  
Xiao Jun Wang ◽  
Xiao Guang Fu
Keyword(s):  
Machine Tool ◽  
Error Compensation ◽  
Reference Value ◽  
Geometric Error ◽  
Numerical Control ◽  
Control Machine Tool ◽  
Nc Machine Tool ◽  
Machining Center ◽  
Compensation Methods ◽  
Nc Machine

In this paper the characteristics of geometric errors is discussed in detail, error compensation methods used in productive practice and relevant examples are given. Finally, the application of error compensation in different situation is discussed according to the characteristics of machining center. The machine accuracy can be improved by error compensation. It has important practical reference value for reasonable use and maintaining of NC machine tool.

scholarly journals Fabrication of Edge Rounded Polylactic Acid Biomedical Stents by the Multi-Axis Micro-Milling Process

2020 ◽  
Vol 10 (8) ◽  
pp. 2809
Author(s):  
Fuh-Yu Chang ◽  
Yan-Chiau Chen ◽  
Te-Hsien Liang ◽  
Zong-Yan Cai
Keyword(s):  
Machine Tool ◽  
Polylactic Acid ◽  
Laser Processing ◽  
Software Package ◽  
Milling Process ◽  
Numerical Control ◽  
Micro Milling ◽  
Center Of Rotation ◽  
Five Axis ◽  
Optimal Cutting Parameters

This paper presents the first try to fabricate degradable polylactic acid (PLA) biomedical stents with round edges by the multi-axis micro-milling process. Conventionally biomedical stents are produced by laser processing. Post-processing operations are usually required to handle sharp edges and thermal defects of the stent due to laser processing. A computer graphics software package was used to design the strut structures with round corners of the PLA stent. A PLA tube was first created using injection molding, and a degradable biomedical stent was then fabricated through micro-milling by using a five-axis computer numerical control (CNC) machine tool. This study investigated the error in the rotation center that can occur during five-axis micro-milling. Data obtained from experiments on center-of-rotation errors were substituted into homogeneous coordinate conversion formulas. Center-of-rotation errors in the five-axis machine tool were compensated for improving the milling precision (A and C axes) to be within 5 μ m. Furthermore, milling parameter optimization experiments were conducted, which determined the optimal conditions for milling PLA to be a spindle speed of 60,000 rpm, feed per tooth of 0.005 mm, and feed rate of 600 mm/min, and achieved the minimum burr 0.01 mm and the average surface roughness (Ra) 0.4 μ m. These optimal cutting parameters will be used in the following actual stent processing experiments. Finally, the error compensation and optimal parameters were combined in a CAM software package and layered spiral micromilling to machine the actual stent. The experimental results revealed that the combination of five-axis micro-milling led to the successful fabrication of a degradable biomedical stent (stent diameter = 6 mm, strut width = 0.3 mm, and radius at round corners = 0.1 mm). The machined actual stent had cross-section height and width errors within 0.01 mm, and arc depth of cut variation within 6 μ m. In addition, the PLA stent machining results indicated a rebound of approximately 33% at the strut round edge machining. This work may also open up future possibilities for complex three-dimensionally structured biomedical stents for better performance and special functionality.

Ergonomic Design of CNC Milling Machine for Safe Working Posture

2013 ◽  
Vol 465-466 ◽  
pp. 60-64 ◽  
Author(s):  
Halim Isa ◽  
M.A. Rahman ◽  
Hasan Hazmilah ◽  
Haeryip Sihombing ◽  
Adi Saptari ◽  
...  
Keyword(s):  
Quality Function Deployment ◽  
Numerical Control ◽  
Future Research ◽  
Milling Machine ◽  
Cnc Milling ◽  
Cnc Milling Machine ◽  
Working Posture ◽  
Milling Operation ◽  
Technical Specifications ◽  
Safe Working

In milling operation, Computer Numerical Control (CNC) milling machine has been recognized as one of effective solutions for high productivity, efficiency, and precision. However, the existing CNC milling machine has contributed to ergonomics-related problems such as awkward working posture. The aim of this study is to redesign the existing CNC milling machine by considering working posture of the machinist. This study performed questionnaire survey to determine ergonomics feature requirements from the machinist. The requirements of the machinist are then translated using Quality Function Deployment (QFD) to obtain technical specifications of new design CNC milling machine. The working posture of machinist during operating the existing CNC milling machine and the redesigned CNC milling machine was assessed using Rapid Upper Limb Assessment (RULA). Based on the analysis, the redesigned CNC milling machine has improved the working posture as shown by low score of RULA. This study concluded that by considering the ergonomics feature requirements to the design of CNC milling machine enabled the machinists to perform milling operation in safe working posture. This study suggests that environmental factors should be considered in the future research works.

Analysis on the NC Milling Machining Precision and the Error

2014 ◽  
Vol 926-930 ◽  
pp. 1214-1217
Author(s):  
Bo Tang
Keyword(s):  
Process Design ◽  
Process Analysis ◽  
Milling Process ◽  
Numerical Control ◽  
Machining Process ◽  
Cnc Milling ◽  
Machining Precision ◽  
Cnc Milling Machine ◽  
Process Route ◽  
Nc Milling

the numerical control milling process design is on the basis of ordinary milling process design, combining with the characteristics of CNC milling machine, give full play to its advantages. CNC milling process design is the key to reasonable arrangement of process route, to coordinate the relationship between the CNC milling process and other process, determine the content and steps of NC milling process make the necessary preparations for programming. NC milling machining process analysis is related to the effectiveness and success or failure, is one of the important preparations before programming. This article will mainly for NC milling machining precision and machining error analysis and research.

scholarly journals Application of Bayesian Family Classifiers for Cutting Tool Inserts Health Monitoring on CNC Milling

2021 ◽  
Vol 11 (2) ◽  
Author(s):  
Abhishek D. Patange ◽  
R Jegadeeshwaran
Keyword(s):  
Condition Monitoring ◽  
Cutting Tool ◽  
Milling Process ◽  
Supervised Machine Learning ◽  
Cnc Milling ◽  
Self Monitoring ◽  
Tool Condition ◽  
Computer Numerically Controlled ◽  
The Face ◽  
Machining Operations

The customized usage of tool inserts plays an imperative role in the economics of machining operations. Eventually, any in-process defects in the cutting tool lead to deterioration of complete machining activity. Such defects are untraceable by the conventional practices of condition monitoring. The characterization of such in-process tool defects needs to be addressed smartly. This would also assist the requirement of ‘self-monitoring’ in Industry 4.0. In this context, induction of supervised Machine Learning (ML) classifiers to design empirical classification models for tool condition monitoring is presented herein. The variation in faulty and fault-free tool condition is collected in terms of vibrations during the face milling process on CNC (Computer Numerically Controlled) machine tool. The statistical approach is incorporated to extract attributes and the dimensionality of the attributes is reduced using the J48 decision tree algorithm. The various conditions of tool inserts are then classified using two supervised algorithms viz. Bayes Net and Naïve Bayes from the Bayesian family.

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