Machining Based Geometric Error Estimation Method for 3-Axis CNC Machine

2019 ◽  
Vol 889 ◽  
pp. 469-474
Author(s):  
Trung Kien Hoang ◽  
Nguyen Minh Duc Ta
Keyword(s):  
Machine Tool ◽  
High Accuracy ◽  
Geometric Error ◽  
Numerical Control ◽  
Cnc Machine Tool ◽  
Cnc Machine ◽  
Simple Method ◽  
Volumetric Errors ◽  
Measuring Machine ◽  
Cutting Path

Computer numerical control (CNC) machine tool plays an extremely significant role in any manufacturing industry due to its automation and high accuracy. Keeping the CNC machine tool at its highest performance to meet the demand of high accuracy machining is always significant. To maintain the accuracy of a machine tool over the time, it is important to measure and compensate the geometric error, one of the main error source of machine tool, especially when the machine get old. There are totally 21 geometrical errors in a 3-axis machine tool including three translational errors and three rotational errors for each axis and three perpendicular error (Squareness) within three axes of the machine. This paper presents an economical and simple method for measuring the geometric error of a 3-axis CNC machine tool based on the machining of actual samples. Three samples for each axis will be machined following a design cutting path. The samples will then be measured using a coordinate measuring machine (CMM). The collect data will be used for estimating the geometric errors. The volumetric errors will be then computed and verified through machining of 3D geometries.

Development of a High-Speed and High-Accuracy Machining System Based on Servo-Data Control – Evaluation of Prototype System –

2011 ◽  
Vol 5 (6) ◽  
pp. 855-861 ◽  
Author(s):  
Mikio Fujio ◽  
Keyword(s):  
Machine Tool ◽  
High Speed ◽  
Geometric Model ◽  
High Accuracy ◽  
Numerical Control ◽  
Prototype System ◽  
Cnc Machine Tool ◽  
Accuracy Control ◽  
Cnc Machine ◽  
Machining System

High-speed and high-accuracy control technology has been developed in Japan and applied to CNC (Computer Numerical Control) machine tools. Therefore, a CNC machine tool, which is made in Japan, has shown a successful history of its performance. Further development of these technologies is important for Japan to maintain its leadership in advanced manufacturing. The purpose of this research is to develop a high-speed and high-accuracy machining system. Two methods are implemented in the proposed prototype system. The first method is “geometric-model interpolation,” which is used to generate high-speed and highaccuracy command positions, and the second method is “predictive compensation,” which is used to correct machining errors. In the proposed prototype system, these errors are simulated preliminarily and compensated for in the servo data by controlling the position and the feed rate. This report describes the configuration of the proposed prototype system, and the performance of the prototype is evaluated by comparing its speed and accuracy with an existing commercial CNC machine tool. The results show that the prototype system is able to control a CNC machine tool with higher speed and greater accuracy than current CNC machine tool systems.

Geometric Error Modeling and Sensitivity Analysis of Single-Axis Assembly in Three-Axis Vertical Machine Center Based on Jacobian-Torsor Model

2017 ◽  
Vol 4 (3) ◽  
Author(s):  
Du Zhengchun ◽  
Wu Jian ◽  
Yang Jianguo
Keyword(s):  
Sensitivity Analysis ◽  
Machine Tool ◽  
Geometric Error ◽  
Error Modeling ◽  
Numerical Control ◽  
Cnc Machine Tool ◽  
Cnc Machine ◽  
Machine Center ◽  
Mechanical Parts ◽  
Final Error

The influence of component errors on the final error is a key point of error modeling of computer numerical control (CNC) machine tool. Nevertheless, the mechanism by which the errors in mechanical parts accumulate to result in the component errors and then impact the final error of CNC machine tool has not been identified; the identification of this mechanism is highly relevant to precision design of CNC machine. In this study, the error modeling based on the Jacobian-torsor theory is applied to determine how the fundamental errors in mechanical parts influence and accumulate to the comprehensive error of single-axis assembly. First, a brief introduction of the Jacobian-torsor theory is provided. Next, the Jacobian-torsor model is applied to the error modeling of a single-axis assembly in a three-axis machine center. Furthermore, the comprehensive errors of the single-axis assembly are evaluated by Monte Carlo simulation based on the synthesized error model. The accuracy and efficiency of the Jacobian-torsor model are verified through a comparison between the simulation results and the measured data from a batch of similar vertical machine centers. Based on the Jacobian-torsor model, the application of quantitative sensitivity analysis of single-axis assembly is investigated, along with the analysis of key error sources to the synthetical error ranges of the single-axis assembly. This model provides a comprehensive method to identify the key error source of the single-axis assembly and has the potential to enhance the tolerance/error allocation of the single axis and the whole machine tool.

Study on Generation and Optimization Methodology of On-Machine Measurement Schemes for Multi-Axis CNC Machine Tool

2017 ◽  
Author(s):  
Zhao Bohan ◽  
Gao Feng ◽  
Li Yan ◽  
Zhang Dongya ◽  
Zhang Wanli ◽  
...  
Keyword(s):  
Machine Tool ◽  
Large Scale ◽  
Coordinate Measuring Machine ◽  
Measuring Error ◽  
Cnc Machine Tool ◽  
Cnc Machine ◽  
Real Time Control ◽  
Position Detection ◽  
Volumetric Errors ◽  
Measuring Machine

Quality Control (QC) is one of the most important phases in the production process. In tradition, the workpiece must be inspected for dimension and shape errors in the QC lab or Coordinate Measuring Machine (CMM) after being machined, which is time-consuming and labor-intensive, especially for large scale parts. Thus the only practical way to do that is to migrate the critical primary inspection operations upstream from the QC lab or CMM to the production floor, and that’s what On-Machine Measurement (OMM) does. OMM technology can inspect the workpiece on its operating station by motion control and the position detection function of CNC machine tool, by which the measuring error caused by the misalignment between measuring datum and manufacturing datum can be avoided accurately. Therefore, it is a feasible way to achieve the real-time control of the manufacturing process and improve the manufacturing accuracy and efficiency. The servo axes of multi-axis CNC machine tool might be redundant for being used in OMM, which will result in that one measurement task could be done by different servo motion schemes. In addition, the map between the machine accuracy and measuring accuracy has not been found out previously. Thus, how to determine metering schemes to measure a workpiece with high accuracy and efficiency is one of the most important problems and also a hotspot for everybody. To solve this problem, a generation method of task-oriented OMM scheme is proposed. Utilizing multi-body system theory and transformation of homogeneous coordinates, a function relationship between the geometrical characteristic of workpiece as independent variables and motions of machine tool as dependent variables is established. All possible metering schemes are obtained by analyzing the solution of functional equation. Then the performance of measurement scheme can be evaluated by comparing the measuring errors of each scheme after building a mapping relationship between the machine tool volumetric errors and measuring errors. In the end, a case study was accomplished, and the correctness and efficiency of the methodology has been verified.

The Stiffness Analysis and Modeling Simulation of Ball Screw Feed System

2010 ◽  
Vol 97-101 ◽  
pp. 2914-2920 ◽  
Author(s):  
Qin Wu ◽  
Zhi Yuan Rui ◽  
Jian Jun Yang
Keyword(s):  
Machine Tool ◽  
Control Strategy ◽  
Feedforward Control ◽  
Dynamic Performance ◽  
Numerical Control ◽  
Ball Screw ◽  
Axial Stiffness ◽  
Cnc Machine Tool ◽  
Cnc Machine ◽  
Feed System

The computer numerical control (CNC) machine tool was investigated and the dynamics model for the servo feed system was established. Based on the fixing constraint of the ball screw, the mathematical models of axial stiffness and torsion stiffness are constructed. According to the effects of stiffness on the dynamic performance, the simulation model for CNC machine tool feed system with stiffness considered was set up by the dynamic simulation tool Simulink, and a curve representing the performance of the system was obtained. To reduce the effect of stiffness on the system, the feedforward control strategy is used for stiffness compensation. The simulation results show that the stability and response performances of the system are improved and the steady-state error of the system is reduced by the control strategy.

Study on Fault Diagnosis and Repair Strategy of CNC Machine Tool

2013 ◽  
Vol 791-793 ◽  
pp. 967-970
Author(s):  
Guo Min Lin ◽  
Miao Shang ◽  
Wen Guang Zhang
Keyword(s):  
Fault Diagnosis ◽  
Machine Tool ◽  
Numerical Control ◽  
Ball Screw ◽  
Cnc Machine Tools ◽  
Cnc Machine Tool ◽  
Cnc Machine ◽  
Repair Strategy ◽  
Hardware Faults ◽  
Main Spindle

CNC machine tool fault types, repair characteristics, the principle to be followed are described. The mechanical systems, Numerical control system, servo system fault diagnosis and repair for CNC machine tools are analyzed in detail. The strategy of the hardware faults such as main spindle part, the ball screw-nut pairs, cutter and tool change device, the strategy of the software repair are proposed.

Experimental Study on Backlash Compensation of CNC Machine Tool

2012 ◽  
Vol 580 ◽  
pp. 419-422 ◽  
Author(s):  
Xiao Long Shen ◽  
Jia Ying Hu ◽  
Ming Jun Zhang ◽  
Lai Xi Zhang
Keyword(s):  
Machine Tool ◽  
Evaluation System ◽  
High Speed ◽  
Basic Feature ◽  
Geometric Error ◽  
Cnc Machine Tool ◽  
Cnc Machine ◽  
Position Accuracy ◽  
Different Types ◽  
Types Of Error

The backlash compensation has a great effect on the synthetical precision of CNC machine tool. Here, the measuring and backlash compensating technologies were investigated for high-speed CNC machine tool. Following, the backlash compensation of the synthetical geometric error of the interpolatimg movement and the evaluation system of position accuracy were proposed during CNC machine tool processing. The results indicate that the basic feature of error is established and provides a basis for putting forward the new error measurement method under the essential measuring condition. It also could be applied for different types of error compensation, shows that the backlash of the milling processing could be well compensated.

A Review of Geometric Error Modeling and Error Detection for CNC Machine Tool

2013 ◽  
Vol 303-306 ◽  
pp. 627-631 ◽  
Author(s):  
Zhen Yu Han ◽  
Hong Yu Jin ◽  
Yu Long Liu ◽  
Hong Ya Fu
Keyword(s):  
Machine Tool ◽  
Error Detection ◽  
Error Compensation ◽  
Machine Tools ◽  
Performance Criterion ◽  
Geometric Error ◽  
Error Modeling ◽  
Cnc Machine Tool ◽  
Cnc Machine ◽  
Error Sources

Error compensation can improve the accuracy of machine tools effectively. Among the error sources affecting the accuracy of CNC machine tool, geometric error is always set as a key performance criterion. This paper summarizes several methods of geometric error modeling and reviews the characteristics of different methods. Furthermore, available methods for measuring geometric errors have been reviewed also based on the advanced instruments. This work aims at enhancing the efficiency of error detection and give a perspective for the application of error compensation in the future.

The Architecture of Reliability Information System for CNC Machine Tool in Concurrent Engineering

2004 ◽  
Vol 471-472 ◽  
pp. 603-607 ◽  
Author(s):  
Q. Zhang ◽  
S.J. Liu ◽  
C.Y. Duan ◽  
Y.M. Zhu
Keyword(s):  
Information System ◽  
Machine Tool ◽  
Reliability Analysis ◽  
Concurrent Engineering ◽  
Numerical Control ◽  
Cnc Machine Tool ◽  
Cnc Machine ◽  
Analysis System ◽  
Current Engineering ◽  
General Guidance

Based on the functional requirement analysis of the compute-aided reliability information system, some concepts are proposed, such as the distributed progressive reliability analysis and the functional decomposition and reconstitution for CNC machine tool. At the same time, the architecture of the CARNC-CE (Computer Aided Reliability Numerical Control for Current Engineering) including physical layer, foundational layer, executive layer, applied layer and illustration layer, is introduced, which provides the general guidance and the frame to realize CNC machine tool reliability analysis system in concurrent engineering.

ANALYSIS AND COMPENSATION OF STIFFNESS IN CNC MACHINE TOOL FEED SYSTEM

2011 ◽  
Vol 10 (01) ◽  
pp. 77-84 ◽  
Author(s):  
BAOSHENG WANG ◽  
JIANMIN ZUO ◽  
MULAN WANG
Keyword(s):  
Steady State ◽  
Machine Tool ◽  
Numerical Control ◽  
Axial Stiffness ◽  
Cnc Machine Tool ◽  
Cnc Machine ◽  
Feed System ◽  
Dead Band ◽  
Torsion Stiffness ◽  
State Error

Based on the elastic mechanics theory, the mathematical models of axial stiffness and torsion stiffness are constructed in accordance with single end thrust and two ends thrust. The effects of stiffness on dead band error are analyzed. With the analysis of displacement deviation induced by axial stiffness and angular displacement deflection caused by torsion stiffness, a formula to calculate the dead band error is presented. A model for Computer Numerical Control (CNC) machine tool feed system with stiffness is established. By applying computer simulation, dynamic performances, static performances and steady-state error of the system are analyzed. To reduce the effect of stiffness on the system, the feedforward control method is used to compensate stiffness. The simulation analysis shows the result that dynamic and static performances are improved, as well as steady-state error of the system is reduced by more than 58% with this approach.

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