scholarly journals Level Detection Equipment for Measuring the Influence of Different Leveling Accuracies on Linear Error

2021 ◽  
Vol 2021 ◽  
pp. 1-15
Author(s):  
Shao-Hsien Chen ◽  
Chi-Li Ji

This study developed a level detection equipment which is used in computer numerical control (CNC) machine tool to determine the impact of leveling accuracy on rectilinear motion accuracy. When the CNC precision machine tool has accuracy deterioration under external load or internal stress, mainly caused error is leveling error, this research and development equipment can immediate to analyze and measurement. The allowable error of leveling accuracy can be obtained after experimental validation. The kinematic error relatively increases with leveling error. When the leveling accuracy is within the allowable error, the kinematic error relatively decreases. The main kinematic error items measured in this study include EXX, EBY, EAX, and EYY. The level detection equipment is developed in this study, and the fuzzy regression analysis is used for modeling. The model that has high accuracy in the test of the X -axis is R 2 = 0.9764 and P = 0.0506 , and Y -axis is R 2 = 0.9756 and P = 0.0524 . In terms of filtering, Kalman filtering is used for signal processing, the measured values and X -axis and Y -axis after filtering are improved by 94.1% and 86.2%, respectively, the repeatability of this system is about A grade capability of precision (Cp), resolution is ±0.0001°, and the stability is at least B grade capability of accuracy (Ca). This equipment has the advantages of low cost, high precision, and 2-axis measurement. This machine tool which has the straightness increases with X and Y axes’ leveling accuracy errors, when the X / Y leveling accuracy is within ±0.01 mm/m, and there is the best straightness and conforms to the ISO230 standard (Lee et al., 2020).

2021 ◽  
Author(s):  
Xinxin LI ◽  
Zhi-Min Li ◽  
Sun Jin ◽  
Jichang Zhang ◽  
Siyi Ding ◽  
...  

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.


Author(s):  
Shih-Ming Wang ◽  
Chih-Peng Yang ◽  
Zhe-Zhi Ye ◽  
Chuntai Yen

The products of 3C, bioscience, medical industry, and aerospace industry are becoming smaller and smaller. The components of the products are made of various materials with complex 3D shapes requiring high accuracy in their dimensions and contours. An accurate micro-/meso-scale CNC machine tool is an essential part of this technology. A new type of CNC micro machine tool with a toggle-like mechanism having the characteristics of low-cost and fine-resolution was developed. With geometric reduction principle, the machine can provide finer feed resolution and better positioning accuracy without using high-end driving components and controller. The kinematics model and characteristics of the machine were derived and analyzed. Modal analysis and dynamic compliance analysis were employed to design a light-weight structure with good stiffness. The accuracy calibration results showed the machine can reach a positioning accuracy of 500 nm. Prototype of the machine was built, and furthermore some micro machining examples were demonstrated in this paper.


Author(s):  
Amro Shafik ◽  
Salah Haridy

Computer Numerical Control (CNC) is a technology that converts coded instructions and numerical data into sequential actions that describe the motion of machine axes or the behavior of an end effector. Nowadays, CNC technology has been introduced to different stages of production, such as rapid prototyping, machining and finishing processes, testing, packaging, and warehousing. The main objective of this chapter is to introduce a methodology for design and implementation of a simple and low-cost educational CNC prototype. The machine consists of three independent axes driven by stepper motors through an open-loop control system. Output pulses from the parallel port of Personal Computer (PC) are used to drive the stepper motors after processing by an interface card. A flexible, responsive, and real-time Visual C# program is developed to control the motion of the machine axes. The integrated design proposed in this chapter can provide engineers and students in academic institutions with a simple foundation to efficiently build a CNC machine based on the available resources. Moreover, the proposed prototype can be used for educational purposes, demonstrations, and future research.


Sensors ◽  
2019 ◽  
Vol 19 (20) ◽  
pp. 4506 ◽  
Author(s):  
Hyungjung Kim ◽  
Woo-Kyun Jung ◽  
In-Gyu Choi ◽  
Sung-Hoon Ahn

In the new era of manufacturing with the Fourth Industrial Revolution, the smart factory is getting much attention as a solution for the factory of the future. Despite challenges in small and medium-sized enterprises (SMEs), such as short-term strategies and labor-intensive with limited resources, they have to improve productivity and stay competitive by adopting smart factory technologies. This study presents a novel monitoring approach for SMEs, KEM (keep an eye on your machine), and using a low-cost vision, such as a webcam and open-source technologies. Mainly, this idea focuses on collecting and processing operational data using cheaper and easy-to-use components. A prototype was tested with the typical 3-axis computer numerical control (CNC) milling machine. From the evaluation, availability of using a low-cost webcam and open-source technologies for monitoring of machine tools was confirmed. The results revealed that the proposed system is easy to integrate and can be conveniently applied to legacy machine tools on the shop floor without a significant change of equipment and cost barrier, which is less than $500 USD. These benefits could lead to a change of monitoring operations to reduce time in operation, energy consumption, and environmental impact for the sustainable production of SMEs.


2010 ◽  
Vol 97-101 ◽  
pp. 2914-2920 ◽  
Author(s):  
Qin Wu ◽  
Zhi Yuan Rui ◽  
Jian Jun Yang

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.


2013 ◽  
Vol 791-793 ◽  
pp. 967-970
Author(s):  
Guo Min Lin ◽  
Miao Shang ◽  
Wen Guang Zhang

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.


Author(s):  
S H Ahn ◽  
S McMains ◽  
C H Séquin ◽  
P K Wright

Inspired by the metal oxide system implementation service (MOSIS) project, CyberCut is an experimental fabrication testbed for an Internet-accessible, computerized prototyping and machining service. Client-designers can create mechanical components, generally using our web-based computer aided design (CAD) system (available at http://cad.berkeley.edu ), and submit appropriate files to the server at Berkeley for process planning. CyberCut then utilizes an open-architecture, computer numerical control (CNC) machine tool for fabrication. Rapid tool path planning, novel fixturing techniques and sensor-based precision machining techniques allow the designer to take delivery of a component machined from high-strength materials with good tolerances, e.g. ±0.002in (0.05 mm). There are also instances where the complex geometry of a component cannot be prototyped on our three-axis machine tool. For these components use is made of solid freeform fabrication (SFF) technologies such as fused deposition modelling (FDM) to build a prototype of the design. Based on experience with this testbed, a new characterization of types of relationship, or ‘couplings’, between design and manufacturing has been developed using the three classifications ‘loose and repetitive’, ‘stiff and one-way’ or ‘strong and bidirectional’. These three couplings represent different trade-offs between ‘design flexibility’ and ‘guaranteed manufacturability’.


2012 ◽  
Vol 430-432 ◽  
pp. 2026-2031
Author(s):  
Yue Wang ◽  
Jia Ying Zhang

The design thought of "dual-CPU architecture" is used on the basis of a deep study of embedded systems and multi-functional CNC machine tools. That is to say, microprocessor S3C2440A of Samsung ARM9 series is used as control core, whose PWM timer produces pulse to realize the automatic control of the process. As the main control center, it plays the main functions of NC program input, keyboard entry, LCD display, the interpretation of the program, crude interpolation and so on. Using CPU as auxiliary equipment, it receives signals from master control center to realize fine interpolation through further calculation. Simultaneously the periphery of the system expands modules of human-computer interaction, communication, servo, and input/output to realize human-machine interaction, data communication and motor control. Finally, the hardware modules are debugged and the results are analyzed, which shows that the system is of fast response, reliability, low cost and good cutting and portability. This system has achieved the desired anticipation and has broad prospect in the economical CNC field which requires fast moving and proper processing speed.


2004 ◽  
Vol 471-472 ◽  
pp. 603-607 ◽  
Author(s):  
Q. Zhang ◽  
S.J. Liu ◽  
C.Y. Duan ◽  
Y.M. Zhu

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.


2011 ◽  
Vol 10 (01) ◽  
pp. 77-84 ◽  
Author(s):  
BAOSHENG WANG ◽  
JIANMIN ZUO ◽  
MULAN WANG

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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