Measuring Points Selection for Laser Tracker Measurement of Five-Axis Machine Tool

2018 ◽  
Author(s):  
Qingzhao Li ◽  
Wei Wang ◽  
Hai Li ◽  
Jing Zhang ◽  
Zhong Jiang
Keyword(s):  
Machine Tool ◽  
High Efficiency ◽  
Optimization Criterion ◽  
Measurement Scale ◽  
Laser Tracker ◽  
Large Measurement ◽  
Measurement Efficiency ◽  
Five Axis ◽  
Selection Of

Due to the advantages of high efficiency, good flexibility and large measurement scale, the laser tracker measurement method is widely used in the error measurement of the machine tool. For the laser tracker measurement, the selection of the measuring points in the workspace has a significant influence on the identification effect of the errors. In this paper, the method to select the optimal measuring points is proposed. By construction of the suitable error vector and its corresponding error transformation matrix, the optimization criterion in robotic area is adopted to evaluate the identification effect of the measuring points. Based on the optimization criterion, the scheme of the measuring points selection can be established. The method proposed is validated by a case study. The method can help increase both the measurement efficiency and the error identification effect.

New Development in High Efficiency Deep Grinding

2012 ◽  
Author(s):  
Andre D. L. Batako ◽  
Valery V. Kuzin ◽  
Brian Rowe
Keyword(s):  
Machine Tool ◽  
High Efficiency ◽  
Machining Process ◽  
Depth Of Cut ◽  
Removal Rates ◽  
Workpiece Surface ◽  
New Development ◽  
Cutting Processes ◽  
Selection Of ◽  
Made In

High Efficiency Deep Grinding (HEDG) has been known to secure high removal rates in grinding processes at high wheel speed, relatively large depth of cut and moderately high work speed. High removal rates in HEDG are associated with very efficient grinding and secure very low specific energy comparable to conventional cutting processes. Though there exist HEDG-enabled machine tools, the wide spread of HEDG has been very limited due to the requirement for the machine tool and process design to ensure workpiece surface integrity. HEDG is an aggressive machining process that requires an adequate selection of grinding parameters in order to be successful within a given machine tool and workpiece configuration. This paper presents progress made in the development of a specialised HEDG machine. Results of HEDG processes obtained from the designed machine tool are presented to illustrate achievable high specific removal rates. Specific grinding energies are shown alongside with measured contact arc temperatures. An enhanced single-pole thermocouple technique was used to measure the actual contact temperatures in deep cutting. The performance of conventional wheels is depicted together with the performance of a CBN wheel obtained from actual industrial tests.

A Complete, Continuous, and Minimal Product of Exponentials-Based Model for Five-Axis Machine Tools Calibration With a Single Laser Tracker, an R-Test, or a Double Ball-Bar

2019 ◽  
Vol 141 (4) ◽  
Author(s):  
Peng Xu ◽  
Benny C. F. Cheung ◽  
Bing Li
Keyword(s):  
Machine Tool ◽  
Machine Tools ◽  
Rigid Bodies ◽  
Error Model ◽  
Laser Tracker ◽  
Calibration Model ◽  
Transformation Matrices ◽  
Double Ball Bar ◽  
Ball Bar ◽  
Five Axis

Calibration is an important way to improve and guarantee the accuracy of machine tools. This paper presents a systematic approach for position independent geometric errors (PIGEs) calibration of five-axis machine tools based on the product of exponentials (POE) formula. Instead of using 4 × 4 homogeneous transformation matrices (HTMs), it establishes the error model by transforming the 6 × 1 error vectors of rigid bodies between different frames resorting to 6 × 6 adjoint transformation matrices. A stable and efficient error model for the iterative identification of PIGEs should satisfy the requirements of completeness, continuity, and minimality. Since the POE-based error models for five-axis machine tools calibration are naturally complete and continuous, the key issue is to ensure the minimality by eliminating the redundant parameters. Three kinds of redundant parameters, which are caused by joint symmetry information, tool-workpiece metrology, and incomplete measuring data, are illustrated and explained in a geometrically intuitive way. Hence, a straightforward process is presented to select the complete and minimal set of PIGEs for five-axis machine tools. Based on the established unified and compact error Jacobian matrices, observability analyses which quantitatively describe the identification efficiency are conducted and compared for different kinds of tool tip deviations obtained from several commonly used measuring devices, including the laser tracker, R-test, and double ball-bar. Simulations are conducted on a five-axis machine tool to illustrate the application of the calibration model. The effectiveness of the model is also verified by experiments on a five-axis machine tool by using a double ball-bar.

Geometric Error Detection and Identification of a Heavy NC Boring and Milling Machine Tool by Using Laser Tracker

2010 ◽  
Vol 37-38 ◽  
pp. 505-508
Author(s):  
Xian Qiu Zhu ◽  
Dong Gao ◽  
Gang Wei Cui
Keyword(s):  
Machine Tool ◽  
Error Detection ◽  
Large Scale ◽  
Geometric Error ◽  
Laser Tracker ◽  
Milling Machine ◽  
Detection And Identification ◽  
Geometric Error Measurement ◽  
Measurement Efficiency ◽  
Heavy Machine

It is inefficient and complicate to detect geometric errors of a heavy machine tool with large scale dimensions by using traditional laser interferometer. With the development of the laser tracker convenient for measuring large scale dimension, the accuracy of the laser tracker can meet the accuracy requirements for geometric error measurement of heavy machine tools. In this paper a method of using laser tracker for detecting and identifying the error of a heavy NC boring and milling machine tool is introduced. The measuring experiment demonstrates that this new method can improve the measurement efficiency.

Highly efficient and accurate calibration method for the position-dependent geometric errors of the rotary axes of a five-axis machine tool

2020 ◽  
Vol 235 (1-2) ◽  
pp. 23-33
Author(s):  
Shijie Guo ◽  
Shufeng Tang ◽  
Gedong Jiang ◽  
Xuesong Mei
Keyword(s):  
Machine Tool ◽  
Calibration Method ◽  
Identification Accuracy ◽  
Geometric Errors ◽  
Identification Process ◽  
Rotary Axes ◽  
Selection Operator ◽  
Lasso Method ◽  
Measurement Efficiency ◽  
Five Axis

This paper proposes a calibration method for continuous measurements with a double ball bar (DBB) used to identify the position-dependent geometric errors (PDGEs) of the rotary axes of five-axis machine tools. The different DBB installation modes for the rotary axes of the spindle and workbench are established, and the same initial DBB installation position is used for multiple tests. This approach minimizes the number of required DBB installations, which increases the measurement efficiency of the PDGEs of the rotary axes and reduces installation errors. PDGEs identification based on the adaptive least absolute shrinkage and selection operator (LASSO) method is proposed. By assigning coefficients to the PDGEs polynomial, the ill-conditioned problem of the identification process can be effectively avoided, thereby improving the identification accuracy. The measurement and identification methods proposed in this paper are verified by experiments on a five-axis machine tool. After compensation, the PDGEs are obviously reduced and the accuracy indexes of the circular trajectory tests performed under multiaxis synchronous control are obviously improved.

scholarly journals Research on a Five-Axis Machining Center Worktable with Bionic Honeycomb Lightweight Structure

Materials ◽  
2020 ◽  
Vol 14 (1) ◽  
pp. 74
Author(s):  
Lai Hu ◽  
Jun Zha ◽  
Fan Kan ◽  
Hao Long ◽  
Yaolong Chen
Keyword(s):  
Machine Tool ◽  
High Efficiency ◽  
Honeycomb Structure ◽  
Theoretical Research ◽  
Processing Efficiency ◽  
Actual Weight ◽  
Circular Tubes ◽  
Machining Center ◽  
Five Axis ◽  
Better Than

The processing of high-precision aerospace parts requires not only ultra-precision machine tools, but also high-efficiency processing. However, in order to realize high-efficiency processing, besides optimizing the system and process parameters, some subversive research can also be done on the machine tool structure. In this paper, the lightweight research is mainly carried out on the structure of machine tool worktable. The traditional workbench is very “heavy” and “slowness”. If the traditional workbench is subverted and reformed to reduce the weight, the processing efficiency will be improved qualitatively. Therefore, this paper studies the lightweight worktable of CFRP (carbon fiber reinforced polymer) in combination with the biological “honeycomb” shape. At first, the tensile, bending, compressive and laminar shear analysis of CFRP were carried out, and the comprehensive parameters were obtained. Simultaneously, the theoretical research and the honeycomb structure simulation and verification of CFRP worktable are carried out. The results show that the HACT (honeycomb arrangement of circular tubes) is 18.51% better than the SACT (straight arrangement of circular tubes) and 45.05% better than the OW (original worktable) by comparing and analyzing the weight of the three modes (HACT, SACT and OW). The actual weight of bionic honeycomb lightweight worktable is 1100 kg, while the simulation result is 1080.25 kg, with an error of 1.8%. Meanwhile, it is analyzed that the original workbench weight of the five-axis machining center is 2023 kg, while the simulation result is 1998.6 kg, with an error of 1.2%. The lightweight degree is reduced by 45.05%. However, the actual lightweight degree has been reduced by 45.63%. The error between simulation and actual is less than 1.3%. This kind of structural transformation has brought forward cutting-edge innovations to the machine tool processing industry. It provides a reference scheme for related enterprises in the future equipment renovation.

Topik-Topik Komunikasi Dakwah Dalam Mesej Akidah Kepada Masyarakat Orang Asli di Selangor

Sains Insani ◽  
2018 ◽  
Vol 3 (2) ◽  
pp. 15-21
Author(s):  
Zulkefli Aini ◽  
Abdul Ghafar Don ◽  
Ahmad Irdha Mokhtar ◽  
Nur Uswah Ahmad Fauzi
Keyword(s):  
Qualitative Study ◽  
Study Design ◽  
Verbal Feedback ◽  
Structured Interviews ◽  
Orang Asli ◽  
Case Study Design ◽  
Beliefs And Practice ◽  
Islamic Faith ◽  
Selection Of

One of the factors that can affect a person's behavior is a communication message. In the context of the da`wah, preachers who involved actively in da`wah communication with the Orang Asli should be able to ensure that the message conveyed can be understood by the target group. In addition, the selection of the correct messages of da`wah based on the foremost priority simplify the process of sharing information between the preachers and the Orang Asli. Accordingly, this article aims to identify specific topics of Islamic faith (akidah) submitted by the Orang Asli in the process of da`wah communication and to identify verbal feedback given by the preachers to the Orang Asli of the topics. This qualitative study using case study design and data was collected through semi-structured interviews. Interviews involving nine preachers were active in da`wah activity to the Orang Asli community in Selangor. Data were analyzed thematically according to the specified objectives. The study found that the topics frequently raised by the Orang Asli is concerned about belief in Allah, belief in Malaikat, and belief in Qada' and Qadar. The topics may be found within the framework of worldview in their beliefs and practice of ancient traditions. Therefore, the preachers gave verbal feedback on these topics is based on a clear and precise sample corresponding to the level of their thinking. The emphasis on these topics is very important to strengthen and purify the faith of the community.Keywords: Communication; Message; Preacher; Indigenous community Abstrak: Elemen mesej dalam komunikasi merupakan salah satu faktor yang dapat memberi kesan terhadap perubahan tingkah laku seseorang. Dalam konteks dakwah, pendakwah yang terlibat dalam proses komunikasi dakwah dengan Orang Asli seharusnya berkebolehan memastikan kandungan mesej yang disampaikan boleh difahami oleh sasaran dakwahnya. Di samping itu, pemilihan mesej dakwah yang betul mengikut keutamaan memudahkan proses perkongsian maklumat antara pendakwah dengan Orang Asli. Sehubungan dengan itu, artikel ini bertujuan untuk mengenalpasti topik-topik tertentu dalam mesej akidah yang dikemukakan oleh masyarakat Orang Asli kepada pendakwah dan mengenalpasti maklum balas lisan yang diberikan oleh pendakwah kepada Orang Asli terhadap topik tersebut. Kajian kualitatif ini menggunakan reka bentuk kajian kes dengan pengumpulan data melalui temu bual separa struktur. Temu bual melibatkan sembilan orang pendakwah yang aktif dalam aktiviti dakwah masyarakat Orang Asli di Selangor. Data kajian dianalisis secara tematik mengikut objektif yang ditentukan. Kajian ini mendapati bahawa topik-topik yang sering dikemukan oleh Orang Asli kepada pendakwah dalam penyampaian mesej akidah ialah berkenaan tentang keimanan kepada Allah SWT, keimanan kepada malaikat, dan keimanan kepada qada’ dan qadar. Topik-topik berkenaan didapati berada dalam kerangka worldview kepercayaan dan amalan tradisi mereka. Sehubungan dengan itu, pendakwah memberikan maklum balas lisan terhadap topik-topik tersebut adalah berdasarkan keterangan yang jelas dan contoh yang tepat bersesuaian dengan tahap pemikiran mereka. Penekanan terhadap topik-topik tersebut merupakan perkara yang penting dalam rangka mengukuhkan dan memurnikan akidah masyarakat Orang Asli.Kata kunci: Komunikasi; Mesej; Pendakwah; Komuniti Orang Asli

scholarly journals Methodology for Determining the Location of River Ports on a Modernized Waterway Based on Non-Cost Criteria: A Case Study of the Odra River Waterway

2021 ◽  
Vol 13 (6) ◽  
pp. 3571
Author(s):  
Bogusz Wiśnicki ◽  
Dorota Dybkowska-Stefek ◽  
Justyna Relisko-Rybak ◽  
Łukasz Kolanda
Keyword(s):  
Large Scale ◽  
Multicriteria Decision Making ◽  
Research Process ◽  
Optimal Selection ◽  
Investment Projects ◽  
Odra River ◽  
Research Problems ◽  
Selection Of ◽  
Construction Works

The paper responds to research problems related to the implementation of large-scale investment projects in waterways in Europe. As part of design and construction works, it is necessary to indicate river ports that play a major role within the European transport network as intermodal nodes. This entails a number of challenges, the cardinal one being the optimal selection of port locations, taking into account the new transport, economic, and geopolitical situation that will be brought about by modernized waterways. The aim of the paper was to present an original methodology for determining port locations for modernized waterways based on non-cost criteria, as an extended multicriteria decision-making method (MCDM) and employing GIS (Geographic Information System)-based tools for spatial analysis. The methodology was designed to be applicable to the varying conditions of a river’s hydroengineering structures (free-flowing river, canalized river, and canals) and adjustable to the requirements posed by intermodal supply chains. The method was applied to study the Odra River Waterway, which allowed the formulation of recommendations regarding the application of the method in the case of different river sections at every stage of the research process.

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