Symbols for machine tool plates. Numerical control

1972 ◽  
Keyword(s):  
Machine Tool ◽  
Numerical Control

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.

A Novel Error Equivalence Model on the Kinematic Error of the Linear Axis of High-End Machine Tool

2021 ◽  
Author(s):  
Xinxin LI ◽  
Zhi-Min Li ◽  
Sun Jin ◽  
Jichang Zhang ◽  
Siyi Ding ◽  
...  
Keyword(s):  
Machine Tool ◽  
Elastic Deformation ◽  
Numerical Control ◽  
Small Displacement ◽  
Kinematic Error ◽  
Guide Rail ◽  
Linear Guide ◽  
Proposed Model ◽  
Equivalence Model ◽  
Kinematic Errors

Abstract The kinematic errors of the linear axis play a key role in machining precision of high-end CNC (Computer Numerical Control) machine tool. The quantification of error relationship is still an urgent problem to be solved in the assembly process of the linear axis, especially considering the effect of the elastic deformation of rollers. A systematic error equivalence model of slider is proposed to improve the prediction accuracy for kinematic errors of the linear axis which contains the base, the linear guide rail and carriage. Firstly, the geometric errors of assembly surface of linear guide rail are represented by small displacement torsor. According to the theory of different motion of robots, the error equivalence model of a single slider is established, namely the geometric error of assembly surface of linear guide rail and the pose error of slider is equivalent to the elastic deformation of roller. Based on the principle of vector summation, the kinematic error of a single slider is mapped to the carriage and the kinematic error of the linear axis is obtained. Besides, experiments validation of kinematic error model of the linear axis is carried out. It is indicated that the proposed model is accurate and feasible. The proposed model can provide an accurate guidance for the manufacturing and operation performance of the linear axis in quantification, and a more effective reference for the engineers at the design and assembly stage.

Quality characteristic decoupling planning of different meta-action units for computer numerical control machine tool

2019 ◽  
Vol 234 (14) ◽  
pp. 2760-2770 ◽  
Author(s):  
Yan Ran ◽  
Teng Zhang ◽  
Zongyi Mu ◽  
Genbao Zhang ◽  
Hongwei Wang ◽  
...  
Keyword(s):  
Machine Tool ◽  
Optimization Method ◽  
Computer Numerical Control ◽  
Quality Characteristics ◽  
Numerical Control ◽  
Quality Characteristic ◽  
Control Machine Tool ◽  
Action Unit ◽  
Action Units ◽  
Control Machine

Since computer numerical control machine tool is composed of multiple meta-action units to achieve one specific function, including the meta-action units' own quality, it still needs to control the coupling relationships among different meta-action units' quality characteristics to guarantee the whole machine's quality. In this article, a method of quality characteristic decoupling planning based on meta-action unit for computer numerical control machine tool was proposed. Firstly, the coupling constraint models based on meta-action unit were established. Secondly, the comprehensive coupling strengths of meta-action units were calculated and introduced into the design structure matrices. Thirdly, multidisciplinary design optimization method was adopted to obtain the optimized control sequence of different meta-action units' quality characteristics. What is more, automatic pallet changer rotary motion of computer numerical control machine tool was taken as an example to illustrate the rightness and effectiveness of this method.

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.

scholarly journals Assessment of the safety of use of portable machine tools

2018 ◽  
Vol 189 (3) ◽  
pp. 192-205
Author(s):  
Monika Nowak ◽  
Agnieszka Terelak-Tymczyna
Keyword(s):  
Machine Tool ◽  
Working Conditions ◽  
Machine Tools ◽  
Numerical Control ◽  
Milling Machine ◽  
Safety Issues ◽  
Large Size ◽  
Score Method ◽  
Characteristic Features ◽  
Risk Reducing

The article presents safety issues related to on-site machining with the use of portable machine tools. Their advantage is the possibility of machining elements at places in which they are used. This especially refers to large-size constructions, welded elements and any items whose disassembly is technically difficult. The authors present tasks performed by the operators of portable machining equipment, working conditions, construction and characteristic features of portable machine tools on the example of a portable boring machine, milling machine and flange facing machine. The presented characteristics can influence the safety of work with these machines. The information given in the article were used to asses risk at the position of a portable machine tool operator. The assessment was conducted using the Risk Score method taking into account four stages of using portable machine tools, i.e. transport, assembly/disassembly, machining and maintenance. The result of the conducted risk analysis is the proposal of possible risk reducing actions. Due to the specificity of the operation of portable machine tools which significantly impedes the development of a machine tool which would be safe in and of itself, the proposed actions refer mainly to organisational solutions. The work presents also the thesis that it is possible to decrease the risk at this position thanks to the use of numerical control in a portable machine tool. Such a solution may reduce exposure to some identified threats. The issue is presented on the example of a prototype of a portable flange facing machine developed in the Institute of Mechanical Technology ZUT in Szczecin.

Motion Performs Evaluation of a Numerical Machine Tool Based on Extenics Theory

2013 ◽  
Vol 433-435 ◽  
pp. 1161-1164
Author(s):  
Chen Liu ◽  
Xiang Li Bu
Keyword(s):  
Machine Tool ◽  
Evaluation Method ◽  
Element Model ◽  
Weight Coefficient ◽  
Numerical Control ◽  
Control Machine Tool ◽  
Analytic Hierarchy ◽  
Evaluation Indexes ◽  
Relational Degree ◽  
Control Machine

Abstract: In order to evaluate motion performs of a numerical control machine tool objectively, the matter-element model for the motion performs evaluation of the NC was established based on extenics theory, the motion performs evaluation indexes of NC was made of multiple elements. The relational degree was calculated by introducing the relational function in the extension set theory, and the evaluation indexes weight coefficient of NC were defined by using the 1-9 scale law in AHP (the analytic hierarchy process). A numerical control machine tool as a study object, the motion performs was studied by using the extenics theory. The result indicated that the motion performs of this NC was good, the evaluation method possesses a certain practicability.

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