scholarly journals Reliability Modeling and Evaluation Method of CNC Grinding Machine Tool

2018 ◽  
Vol 9 (1) ◽  
pp. 14 ◽  
Author(s):  
Yongjun Liu ◽  
Hua Peng ◽  
Yong Yang
Keyword(s):  
Monte Carlo ◽  
Machine Tool ◽  
Evaluation Method ◽  
Reliability Evaluation ◽  
Numerical Control ◽  
Monte Carlo Algorithm ◽  
Reliability Design ◽  
Cnc Grinding ◽  
Gray Correlation ◽  
Grinding Machine

How to determine subsystem’s reliability and evaluate the whole machine’s reliability of the CNC (computer numerical control) grinding machine tool is important for reliability design and promotion. Each subsystem was modeled by a different distribution based on collected data and the models were optimized by the modified gray correlation degree, which was called the similar slope and close median gray correlation method. Methods of generating random data were proposed for different models. The reliability evaluation algorithm based on Monte Carlo simulation was studied and the whole machine’s reliability of the CNC grinder was evaluated by the algorithm. The evaluation result by the Monte Carlo algorithm was compared using the observed value and the evaluation value by the whole fitting method. The results show that the point estimation value evaluated by the algorithm based on Monte Carlo has high accuracy. The interval estimation by the Monte Carlo method was 20.2% and 38.1% by the observed value and the whole fitting value, respectively, which has more practical engineering significance. The reliability evaluation method can be used to assess the whole CNC grinding machine’s reliability in reliability design, and is also one reference for reliability evaluation of other electromechanical equipment.

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.

scholarly journals A geometric error tracing method based on the Monte Carlo theory of the five-axis gantry machining center

2017 ◽  
Vol 9 (7) ◽  
pp. 168781401770764 ◽  
Author(s):  
Jinwei Fan ◽  
Yuhang Tang ◽  
Dongju Chen ◽  
Changjun Wu
Keyword(s):  
Monte Carlo ◽  
Machine Tool ◽  
Test Piece ◽  
Great Influence ◽  
Numerical Control ◽  
Geometric Errors ◽  
Machining Center ◽  
Machining Errors ◽  
Five Axis ◽  
Tracing Method

This article proposes a tracing method to identify key geometric errors for a computer numerical control machine tool by cutting an S-shaped test piece. Adjacent part relationships and machine tool errors transform relationships are described by topology of the machining center. Global sensitivity analysis method based on quasi-Monte Carlo was used to analyze machining errors. Using this method, key geometric errors with significant influence on machining errors were obtained. Compensation of the key errors was used to experimentally improve machining errors for the S-shaped test piece. This method fundamentally determines the inherent connection and influence between geometric errors and machining errors. Key geometric errors that have great influence on machining errors can be determined quickly with this method. Thus, the proposed tracing method could provide effective guidance for the design and use of machine tools.

scholarly journals Human Reliability Evaluation Based on Objective and Subjective Comprehensive Method Used for Ergonomic Interface Design

2021 ◽  
Vol 2021 ◽  
pp. 1-16
Author(s):  
Xin Liu ◽  
Zheng Liu ◽  
Peng-qing Chen ◽  
Zi-yu Xie ◽  
Bin-jun Lai ◽  
...  
Keyword(s):  
Human Computer Interaction ◽  
Machine Tool ◽  
Interface Design ◽  
Evaluation Method ◽  
Reliability Evaluation ◽  
Assessment Method ◽  
Human Reliability ◽  
Comprehensive Method ◽  
Interaction Interface ◽  
Computer Interaction

In the process of machining, the operator’s incorrect operation using the control human-computer interaction interface may lead to a disastrous effect on the whole production chain such as task failure and system failure. The eight types of using errors about human-computer interaction interface system (misperception, memory lapse, carelessness, improper decision-making, improper operation, improper interface layout design, improper icon and text display design, and improper prompt feedback) are proposed based on the cognition from users. According to the eight types of using error, the human reliability and safety evaluation method is proposed. Considering the variability objective and uncertainty subjective factors in the human-machine interaction process, the human reliability evaluation method is proposed based on objective and subjective comprehensive weighting under ergonomic principles. Firstly, based on the investigation of relevant machine tool interface design, the comprehensive evaluation index system for man-machine reliability of complex interface design is established. Secondly, an objective and subjective comprehensive weight assignment method as the composition of Theilʼs entropy weight method combined with TOPSIS (Technique for Order Preference by Similarity to an Ideal Solution) and improved AHP (analytic hierarchy process) method combined with fuzzy mathematics is proposed. It can not only effectively avoid the impact of excessive subjective factors on empowerment but also fully excavate the real information in the survey data and improve the objectivity and accuracy of the weight data of evaluation indicators at all levels. Thirdly, taking the interface design of CNC machine tool equipment for example, the best human-computer interaction interface design schemes are chosen according to the human reliability evaluation method based on objective and subjective comprehensive method calculated by Entropy-TOPSIS-AHP. Finally, based on eye movement experiments, the use efficiency and accuracy of the human-computer interaction interface design scheme chosen by the assessment method are better than the other design schemes or original one to verify the assessment method validity.

A Novel CNC Grinding Method about Relief Surface of Corner Radius End Mill Based on a CAM System

2011 ◽  
Vol 120 ◽  
pp. 26-31 ◽  
Author(s):  
Cai Xia Zhao ◽  
Fei Tang ◽  
Shu Zhe Li ◽  
Xiao Hao Wang
Keyword(s):  
Numerical Control ◽  
End Mill ◽  
Nc Code ◽  
Corner Radius ◽  
Relief Surface ◽  
Cnc Grinding ◽  
Cup Wheel ◽  
Grinding Machine ◽  
Cnc Grinding Machine ◽  
Five Axis

Corner radius end mill, whose cutting capability is mostly affected by the relief surface, is a kind of highly effective end mill [1]. So a novel mathematical model of relief surface curve about corner radius end mill, which is verified with a five-axis computer numerical control (CNC) grinding machine and simulated based on a system CAM, is derived and presented in the paper. According to the proposed tool coordinates system and the mechanical coordinate of the machine, the relative motion between the cup wheel and the tool is determined. In order to obtain an accurate relief curve when machining, the model of a cup wheel edge is also introduced. The coordinates of grinding point when grinding relief surface are calculated. With the input data of the corner radius end geometry, wheels geometry, wheel setting and machine setting, the NC code is generated automatically from the program. Then the code is used to simulate in 3 Dimension before actual machining. Finally, the NC code will be used for machining in the CNC grinding machine. The roundness of the round corner in the final product is very well, means this model is effective.

Research on Reliability of CNC Grinding Machine Based on Function Structure Tree

2012 ◽  
Vol 588-589 ◽  
pp. 1729-1734 ◽  
Author(s):  
Gui Ping Wang ◽  
Guang Wen Zhou ◽  
Ya Zhou Jia
Keyword(s):  
Cnc Machine Tool ◽  
Cnc Machine ◽  
Function Structure ◽  
Reliability Design ◽  
Failure Data ◽  
Cnc Grinding ◽  
Structure Tree ◽  
Improvement Measures ◽  
Grinding Machine ◽  
Cnc Grinding Machine

Based on the function structure tree ,the spot failure data of CNC grinding machine were analyzed and found out that of the all failure positions in the subsystem of the CNC machine was High-frequency Motor Built-in Spindle an high failure frequent and main criticality failure position . By further in detail analysis found out that the main failure cause of the CNC grinding machine was burning out of components. It was defined the main direction to improve the reliability of this CNC grinding machine and put forward the corresponding improvement measures. It can offer a theory basis for the reliability design and analysis of CNC machine tool .

Research on Evaluation Method of CNC Gear Form Grinding Processing Performance

2014 ◽  
Vol 635-637 ◽  
pp. 1944-1947
Author(s):  
Hui Liang Wang ◽  
Yu Quan Xiong ◽  
Jian Jun Yang ◽  
Kai Xu
Keyword(s):  
Performance Evaluation ◽  
Evaluation Method ◽  
Integrated Model ◽  
Numerical Control ◽  
Tooth Surface ◽  
Machining Performance ◽  
Research On Evaluation ◽  
Gear Grinding ◽  
Grinding Machine

To analyze the machining performance of grinding machine and improve the quality of tooth surface, this paper proposes an integrated model of processing performance evaluation of computer numerical control gear grinding machine. Based on the gear profile grinding machine kinematics principles, the topology modification formulas of tooth surface were deduced. Calculated the process capability index according to experimental data and found that the tooth surface errors were followed normal distribution. The main reason of formation errors was analyzed by cause and effect diagram. Finally, the validity of this integrated model of processing performance evaluation is numerically demonstrated using CNC gear grinding machine.

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