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.

Thermal Error Compensation on Boring & Milling Machining Center Feed System Based on PMAC

2014 ◽  
Vol 945-949 ◽  
pp. 1669-1672
Author(s):  
Jun Sun ◽  
Xing Liu ◽  
Zhi Xuan Li
Keyword(s):  
Real Time ◽  
Error Compensation ◽  
Tool Path ◽  
Thermal Error ◽  
Machining Accuracy ◽  
Feed System ◽  
Nc Machine Tool ◽  
Machining Center ◽  
Nc Machine ◽  
Processing Accuracy

Aiming to deal with thermal error of NC machine tool which can cause reduce of machining accuracy, this paper uses an external error compensation which interacts with NC controllers and PMAC multi-axis and then revises the tool path by adding the error tested in real-time by PMAC card. The processing accuracy is improved eventually. This method can compensate machine geometric errors and thermal errors in real-time. Comparing with other methods of error preventing, this method is more effective and affordable.

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 Study of the Dynamic Characteristics of Ball Screw with a Load Disturbance

2016 ◽  
Vol 2016 ◽  
pp. 1-10 ◽  
Author(s):  
Zhe Du ◽  
Xiao-Lan Zhang ◽  
Tao Tao
Keyword(s):  
Machine Tool ◽  
Dynamic Characteristics ◽  
Numerical Control ◽  
Hertzian Contact ◽  
Ball Screw ◽  
Machining Accuracy ◽  
Contact Deformation ◽  
Nc Machine Tool ◽  
Load Disturbance ◽  
Nc Machine

The dynamic character of ball screw is the key factor that influences the machining accuracy of numerical control (NC) machine tool. To improve the dynamic characteristics of the NC machine tool, it is necessary to study the dynamic characteristics of a ball screw. In this paper, the kinematics of a ball screw mechanism (BSM) are studied to expound the dynamic process of the drive, and the load disturbance is considered to analyze the contact deformation based on the Hertzian contact theory. The velocity relationships among the ball, screw, and nut are analyzed, and the influence of the contact deformation on the dynamic characteristics is simulated and investigated experimentally. The results show that the relationships between the contact deformation, which is affected by the material characteristics, the contact angle, and the load of nut are nonlinear. The contact deformation is a factor that cannot be ignored when considering the dynamic machining error of high-speed and high-precision machine tools.

Accurate Estimation of Cutting Time Based on Control Principle of Machine Tool

2016 ◽  
Vol 10 (3) ◽  
pp. 429-437 ◽  
Author(s):  
Kosuke Saito ◽  
◽  
Hideki Aoyama ◽  
Noriaki Sano ◽  
◽  
...  
Keyword(s):  
Machine Tool ◽  
Machine Tools ◽  
Tool Path ◽  
Estimation Error ◽  
Numerical Control ◽  
Accurate Estimation ◽  
Flexible System ◽  
Acceleration And Deceleration ◽  
Nc Machine ◽  
Control Principle

The accurate estimation of cutting time before beginning a cutting process is necessary to improve the productivity of machining. Commercial computer-aided machining (CAM) systems estimate the cutting time by dividing the tool path length by the designated feed rate in a numerical control (NC) program. However, the actual cutting time generally exceeds the estimated cutting time for curved surfaces because of the acceleration and deceleration of the NC machine tool. There are systems that estimate cutting time while considering acceleration and deceleration along the controlled axes, but these are applicable only to particular machine tools. In this study, a flexible system for the accurate estimation of cutting time, based on the control principle of a machine tool, is developed. Experiments to estimate cutting time are conducted for the machining of complex shapes using two different NC machine tools. The actual cutting time is compared with the cutting time estimated by the developed system and that by a commercial CAM system. The estimation error of the proposed system is only 7%, while that of the commercial CAM system is 51%.

Study of Virtual Numerical Control Milling Simulation System

2009 ◽  
Vol 407-408 ◽  
pp. 174-179
Author(s):  
Xiu Lin Sui ◽  
Zheng Wei Kong ◽  
Jia Tai Zhang ◽  
Xiao Ping Yang
Keyword(s):  
Machine Tool ◽  
Virtual Machine ◽  
Machine Tools ◽  
Tool Path ◽  
Simulation System ◽  
Numerical Control ◽  
Processing Scheme ◽  
Second Development ◽  
Milling Simulation ◽  
Nc Machine

Virtual numerical control milling simulation system, based on UG, is studied oriented to low utilization of NC machines. A virtual machine tools library, standard fixture library and visual machine tool processing environment were established by the second development techniques of UG and VC++. Through the example of XH715 NC machine center, tool path and motion of miller were simulated separately; at last processing scheme was evaluated and optimized. The experimental results show this system possesses good utility, and the utilization of machine tools could thus be improved.

Method of Volumetric Error Compensation for 3-Axis NC Machine Tool

2012 ◽  
Vol 472-475 ◽  
pp. 2371-2376 ◽  
Author(s):  
Jin Dong Wang ◽  
Jun Jie Guo ◽  
Yu Fen Deng ◽  
Hai Tao Li
Keyword(s):  
Machine Tool ◽  
Error Compensation ◽  
Geometric Error ◽  
Machining Process ◽  
Laser Tracker ◽  
Machining Accuracy ◽  
Volumetric Error ◽  
Nc Machine Tool ◽  
Nc Machine ◽  
G Code

Error compensation is an effective method to improve the machining accuracy of NC machine tool. A laser tracker is used to rapidly and accurately detect the geometric error of NC machine tool in the paper. The machine tool is controlled to move on the preset path in the space, and a laser tracker is used to measure the motion trajectory of the machine tool. Each geometric error can be identified by error separation. Based on the error model of 3-axis machine tool, error compensation can be carried out by modifying the machining process (G code). Results of experiment show that, this measurement method is feasible, and modifying the G code for error compensation is also effective.

Study on NC Machine Tool Select Incremental Value Programming and Select Absolute Value Programming of Machining Accuracy

2011 ◽  
Vol 314-316 ◽  
pp. 1652-1660
Author(s):  
Tian Biao Huang
Keyword(s):  
Machine Tool ◽  
Numerical Control ◽  
Machining Accuracy ◽  
High Grade ◽  
Processing Application ◽  
Absolute Value ◽  
Nc Machine Tool ◽  
Incremental Value ◽  
Processing Procedure ◽  
Nc Machine

The most important issue of concern for NC processing operators and designers is to establish perfect numerical control processing procedure, to processes high grade components[7]. The introduction of NC processing application in accordance with the same processing craft is to see whether they result in two kinds of different processing precisions.

NC Machine Position Accuracy Testing and NC System Error Compensation Analysis

2011 ◽  
Vol 130-134 ◽  
pp. 2316-2320
Author(s):  
Ke Zhang ◽  
Zheng Xing Cui ◽  
Li Ya Gai ◽  
Peng Ge ◽  
Dong Gao Cai
Keyword(s):  
Error Compensation ◽  
Laser Interferometer ◽  
Machining Accuracy ◽  
Nc System ◽  
Accuracy Requirement ◽  
Position Accuracy ◽  
Nc Machine ◽  
Nc Machine Tools ◽  
Processing Accuracy ◽  
Modern Manufacturing

NC machine plays an irreplaceable role in the modern manufacturing because of its high machining processing accuracy, quality stable, flexibility. Through using the Renishaw ML10 laser interferometer detect the positioning accuracy and repositioning accuracy of X axis and Z axis of the HTC20 series of NC machine tools. According to the detection result compensate NC system to meet the machining accuracy requirement. The result shows that the error compensation of NC system is a effective method to improve the position accuracy of NC machine.

Aero-Engine Blade Deformation Control of Milling Process

2011 ◽  
Vol 308-310 ◽  
pp. 1198-1204
Author(s):  
Hui Xian Chen ◽  
Hao Li ◽  
Hai Tao Feng ◽  
Min Juan Du
Keyword(s):  
Finite Element ◽  
Finite Element Simulation ◽  
Error Compensation ◽  
Leaf Blade ◽  
Tool Path ◽  
Iterative Solution ◽  
Helical Milling ◽  
Machining Accuracy ◽  
Element Simulation ◽  
Compensation Plan

The leaf blade manufacture precision's influencing factors are numerous, and they have coupling relationship each other. So it is difficult to peel out a single factor on the influencing regularity of the blade's machining accuracy. By researching the engine blades of helical milling state under the existing fixture, the leaf blade deformable model based on the instantaneous milling strength was established. Meanwhile, the off-line multi-level error compensation plan was proposed based on the processing surface static error forecasts and compensation. In order to revise the primitive NC tool path code and eliminate the processing distortion inaccuracy, the elastic deformity on each knife position spot is solved on the basis of iterative solution, using the finite element simulation and milling strength model. By using ANSYS finite element simulation, it receives the real-time error compensation of the tool path. And then The experiment has proven the accuracy and the usability of the compensation plan.

Dynamic Characteristics Analysis for the Headstock of a Vertical Machining Center

2016 ◽  
Vol 836-837 ◽  
pp. 348-358
Author(s):  
Zhe Li ◽  
Song Zhang ◽  
Yan Chen ◽  
Peng Wang ◽  
Ai Rong Zhang
Keyword(s):  
Dynamic Characteristics ◽  
Natural Frequencies ◽  
Vibration Characteristics ◽  
Numerical Control ◽  
Vibration Test ◽  
Machining Accuracy ◽  
Modal Test ◽  
Machining Center ◽  
Characteristics Analysis ◽  
Nc Machine

Dynamic characteristics of numerical control (NC) machine tools, such as natural frequency and vibration property, directly affect machining efficiency and finished surface quality. In general, low-order natural frequencies of critical components have significant influences on machine tool’s performances. The headstock is the most important component of the machine tool. The reliability, cutting stability, and machining accuracy of a machining center largely depend on the structure and dynamic characteristics of the headstock. First, in order to obtain the natural frequencies and vibration characteristics of the headstock of a vertical machining center, modal test and vibration test in free running and cutting conditions were carried out by means of the dynamic signal collection and analysis system. According to the modal test, the first six natural frequencies of the headstock were obtained, which can not only guide the working speed, but also act as the reference of structural optimization aiming at frequency-shift. Secondly, by means of the vibration test, the vibration characteristics of the headstock were obtained and the main vibration sources were found out. Finally the corresponding vibration reduction plans were proposed in this paper. That provides the reference for improving the performance of the overall unit.

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