The National Metrology Institute of Japan (NMIJ) developed an accurate two-point diameter measurement system for a sphere by using a micro-coordinate measuring machine (μ-CMM) with a gauge block for calibrating the radius of the μ-CMM probe. The surface roughness of end faces of the gauge block is a key uncertainty factor and, to reduce this in calibrating the μ-CMM probe, a newly fabricated silicon gauge block with a polished surface roughness of a few nanometers or less was used. To overcome poor repeatability caused by interaction forces acting on the probe, we developed a μ-CMM probe with T-shaped sharp styli and an 8-μm tip radius, which minimized the contact area between the stylus tip and gauge block. A calibrated μ-CMM probe (expanded uncertainty of 7.4 nm; k = 2) equipped with the newly developed T-shaped sharp styli was used to measure the mean two-point diameter of a sphere with an expanded uncertainty of 15 nm (k = 2).
{"title":"Two-point diameter calibration of a sphere by a micro-coordinate measuring machine using a silicon gauge block as a reference standard","authors":"Yohan Kondo , Akiko Hirai , Toshiharu Katsube , Natsumi Kawashima , Youichi Bitou","doi":"10.1016/j.precisioneng.2024.12.003","DOIUrl":"10.1016/j.precisioneng.2024.12.003","url":null,"abstract":"<div><div>The National Metrology Institute of Japan (NMIJ) developed an accurate two-point diameter measurement system for a sphere by using a micro-coordinate measuring machine (μ-CMM) with a gauge block for calibrating the radius of the μ-CMM probe. The surface roughness of end faces of the gauge block is a key uncertainty factor and, to reduce this in calibrating the μ-CMM probe, a newly fabricated silicon gauge block with a polished surface roughness of a few nanometers or less was used. To overcome poor repeatability caused by interaction forces acting on the probe, we developed a μ-CMM probe with T-shaped sharp styli and an 8-μm tip radius, which minimized the contact area between the stylus tip and gauge block. A calibrated μ-CMM probe (expanded uncertainty of 7.4 nm; <em>k</em> = 2) equipped with the newly developed T-shaped sharp styli was used to measure the mean two-point diameter of a sphere with an expanded uncertainty of 15 nm (<em>k</em> = 2).</div></div>","PeriodicalId":54589,"journal":{"name":"Precision Engineering-Journal of the International Societies for Precision Engineering and Nanotechnology","volume":"92 ","pages":"Pages 167-178"},"PeriodicalIF":3.5,"publicationDate":"2024-12-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143176759","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-12-03DOI: 10.1016/j.precisioneng.2024.12.002
Mattia Trombini , Giacomo Maculotti , Domenico Augusto Maisano , Alfonso Pagani , Fiorenzo Franceschini
Photogrammetry inspection is a Machine Vision (MV) technique intensely employed to assess the geometry of industrial assets across several measurement scales, ranging from micro-scales focusing on surface to meso- and large-scales targeting geometrical features and shape.
This research endeavors to conduct a comprehensive comparative evaluation of photogrammetry across different dimensional scale domains, aiming to establish a framework for assessing performance levels in various aspects, driven by the portability of the instrumentation, measurement performance and proficiency. Central to the current methodology is employing a single camera, driven by the research's forward-looking goal to integrate drone technology equipped with a solitary camera as the primary payload. In addition, this work presents a statistical quantitative investigation where the most relevant sources of uncertainty are taken into account. Three case studies about a small truss, a ball-bar, and a collaborative robot accompany the analysis.
Finally, this study proposes a framework for assessing the expanded uncertainty and the relative uncertainty across the scales, revealing that the latter decreases with larger measurand, providing a value of 0.2 % when dealing with meso-scale objects.
{"title":"Scaling photogrammetry: A comparative evaluation and metrological assessment across small- and meso-scale domains","authors":"Mattia Trombini , Giacomo Maculotti , Domenico Augusto Maisano , Alfonso Pagani , Fiorenzo Franceschini","doi":"10.1016/j.precisioneng.2024.12.002","DOIUrl":"10.1016/j.precisioneng.2024.12.002","url":null,"abstract":"<div><div>Photogrammetry inspection is a Machine Vision (MV) technique intensely employed to assess the geometry of industrial assets across several measurement scales, ranging from micro-scales focusing on surface to meso- and large-scales targeting geometrical features and shape.</div><div>This research endeavors to conduct a comprehensive comparative evaluation of photogrammetry across different dimensional scale domains, aiming to establish a framework for assessing performance levels in various aspects, driven by the portability of the instrumentation, measurement performance and proficiency. Central to the current methodology is employing a single camera, driven by the research's forward-looking goal to integrate drone technology equipped with a solitary camera as the primary payload. In addition, this work presents a statistical quantitative investigation where the most relevant sources of uncertainty are taken into account. Three case studies about a small truss, a ball-bar, and a collaborative robot accompany the analysis.</div><div>Finally, this study proposes a framework for assessing the expanded uncertainty and the relative uncertainty across the scales, revealing that the latter decreases with larger measurand, providing a value of 0.2 % when dealing with meso-scale objects.</div></div>","PeriodicalId":54589,"journal":{"name":"Precision Engineering-Journal of the International Societies for Precision Engineering and Nanotechnology","volume":"92 ","pages":"Pages 124-140"},"PeriodicalIF":3.5,"publicationDate":"2024-12-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143176762","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-12-03DOI: 10.1016/j.precisioneng.2024.11.013
Fan Liu , Yanlong Cao , Tukun Li , Jiangxin Yang , Junnan Zhi , Jia Luo , Yuanping Xu , Xiangqian Jiang
This paper proposes and develops a novel method, namely the Partially Iterative Algorithm (PIA), for high-speed assessment of flatness deviation for point cloud data, which is typically measured data obtained by advanced instruments for precision manufacturing, such as optical scanners and industrial computed tomography. Firstly, an enhanced flatness deviation model is established based on the minimum zone principle, which is strictly adhered to the latest ISO definition. Secondly, the proposed method is detailed, including the Dynamic Point Set (DPS), the update scheme, and the terminal condition. Thirdly, comparisons are conducted with typical methods for flatness deviation assessment, along with a practicability test via the simulated dataset and measuring dataset. The results show that the proposed method can accurately and rapidly assess flatness deviation on point cloud data with massive measuring points.
{"title":"A Fast flatness deviation evaluation algorithm for point cloud data","authors":"Fan Liu , Yanlong Cao , Tukun Li , Jiangxin Yang , Junnan Zhi , Jia Luo , Yuanping Xu , Xiangqian Jiang","doi":"10.1016/j.precisioneng.2024.11.013","DOIUrl":"10.1016/j.precisioneng.2024.11.013","url":null,"abstract":"<div><div>This paper proposes and develops a novel method, namely the Partially Iterative Algorithm (PIA), for high-speed assessment of flatness deviation for point cloud data, which is typically measured data obtained by advanced instruments for precision manufacturing, such as optical scanners and industrial computed tomography. Firstly, an enhanced flatness deviation model is established based on the minimum zone principle, which is strictly adhered to the latest ISO definition. Secondly, the proposed method is detailed, including the Dynamic Point Set (DPS), the update scheme, and the terminal condition. Thirdly, comparisons are conducted with typical methods for flatness deviation assessment, along with a practicability test via the simulated dataset and measuring dataset. The results show that the proposed method can accurately and rapidly assess flatness deviation on point cloud data with massive measuring points.</div></div>","PeriodicalId":54589,"journal":{"name":"Precision Engineering-Journal of the International Societies for Precision Engineering and Nanotechnology","volume":"92 ","pages":"Pages 90-100"},"PeriodicalIF":3.5,"publicationDate":"2024-12-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143176761","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-12-03DOI: 10.1016/j.precisioneng.2024.12.001
Junzhong Zhang, Zhihao Shen, Ningsong Qu
Electrochemical jet milling (EJM) offers significant benefits for producing workpieces, showcasing various advantages in terms of quality and design flexibility. However, macro-scale EJM currently encounters limitations regarding machining efficiency and surface precision. A critical determinant of these aspects is the inter-electrode gap (IEG), with its optimization presenting an opportunity to enhance both precision and efficiency. Reducing the IEG is particularly desirable as it promises considerable improvements in machining efficiency and surface quality. Nonetheless, achieving a narrower IEG is challenging due to the risk of sparking from excessively high current densities at the cathode tool tips. To address this issue, this study introduces an innovative cathode tool design tailored to exploit the characteristics of electric in EJM. This design strategically removes the energy concentration area. As a result, this advancement allows for an ultra-narrow IEG of 0.05 mm, setting a new benchmark for the narrowest IEG achievable in macro EJM. Employing this novel cathode tool leads to a substantial leap in machining performance at an IEG of 0.05 mm. When compared with the conventional machining gap of 0.2 mm, the refined 0.05 mm IEG not only boosts the material removal rate by an impressive 107 % but also enhances surface quality. Specifically, the experimental results showed that the minimum surface roughness produced by the RD cathode tool was reduced by nearly 86.2 % than that of the surface produced by the standard cathode tool. Moreover, the overcut area was reduced by nearly 60.1 %, and stray corrosion was eliminated.
{"title":"Overall improvement of macro electrochemical jet milling by utilizing a novel cathode tool with an ultra narrow inter-electrode gap","authors":"Junzhong Zhang, Zhihao Shen, Ningsong Qu","doi":"10.1016/j.precisioneng.2024.12.001","DOIUrl":"10.1016/j.precisioneng.2024.12.001","url":null,"abstract":"<div><div>Electrochemical jet milling (EJM) offers significant benefits for producing workpieces, showcasing various advantages in terms of quality and design flexibility. However, macro-scale EJM currently encounters limitations regarding machining efficiency and surface precision. A critical determinant of these aspects is the inter-electrode gap (IEG), with its optimization presenting an opportunity to enhance both precision and efficiency. Reducing the IEG is particularly desirable as it promises considerable improvements in machining efficiency and surface quality. Nonetheless, achieving a narrower IEG is challenging due to the risk of sparking from excessively high current densities at the cathode tool tips. To address this issue, this study introduces an innovative cathode tool design tailored to exploit the characteristics of electric in EJM. This design strategically removes the energy concentration area. As a result, this advancement allows for an ultra-narrow IEG of 0.05 mm, setting a new benchmark for the narrowest IEG achievable in macro EJM. Employing this novel cathode tool leads to a substantial leap in machining performance at an IEG of 0.05 mm. When compared with the conventional machining gap of 0.2 mm, the refined 0.05 mm IEG not only boosts the material removal rate by an impressive 107 % but also enhances surface quality. Specifically, the experimental results showed that the minimum surface roughness produced by the RD cathode tool was reduced by nearly 86.2 % than that of the surface produced by the standard cathode tool. Moreover, the overcut area was reduced by nearly 60.1 %, and stray corrosion was eliminated.</div></div>","PeriodicalId":54589,"journal":{"name":"Precision Engineering-Journal of the International Societies for Precision Engineering and Nanotechnology","volume":"92 ","pages":"Pages 111-123"},"PeriodicalIF":3.5,"publicationDate":"2024-12-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143176760","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-12-01DOI: 10.1016/j.precisioneng.2024.11.012
Muhammad Ahsan Saleem , Xingzhi Xiao , Saqib Mamoon , Gang Li , Tingting Liu
Inkjet printing offers significant benefits for additive manufacturing (AM) and printed electronics, such as cost-effectiveness, scalability, non-contact printing, and the flexibility for ad-hoc customization. However, some challenges such as stable jetting states and defined printing zone still needs attention. Data driven modeling such as machine/deep learning (ML/DL) as a predictive methodology has proven to reduce the experimental cost and workload in AM for low-viscosity inks. However, there is an oversight in ML extension to high-viscosity inks due to some inherit challenges such as irregular shape formation, and adhesiveness. Therefore, this study is focused on the prediction of jetting states and defining the printing zone for three-dimensional (3D) inkjet printing of high-viscosity ink. The experimental data is comprised of equipment parameter settings, material properties, and camera-captured features. The jetting behavior is recorded with a high-speed camera and carefully categorized into five classes: no jetting, orifice adhesion, droplet jetting, orifice tail, and beads hanging. A robust and efficient high-viscosity 3D printing U-Net (HV3DP-UNet) model is proposed, that achieved the jetting state and printing zone prediction accuracy of 97.98% and 100% respectively. For the fair comparison, three traditional ML and two more DL models are tested and analyzed in detail. The robustness and efficacy of the proposed model is supplemented with four performance metrics, i.e., accuracy, precision, recall and f1-score. The models’ efficacy has been proved by achieving improved results on the public dataset, the proposed model has achieved overall prediction accuracy of 92.95%. The presented data-driven approach serves as a systematic framework for enhancing quality of inkjet-based 3D printing utilizing high-viscosity ink.
{"title":"A novel data driven formulation for predicting jetting states and printing zone of high-viscosity nanosilver ink in inkjet-based 3D printing","authors":"Muhammad Ahsan Saleem , Xingzhi Xiao , Saqib Mamoon , Gang Li , Tingting Liu","doi":"10.1016/j.precisioneng.2024.11.012","DOIUrl":"10.1016/j.precisioneng.2024.11.012","url":null,"abstract":"<div><div>Inkjet printing offers significant benefits for additive manufacturing (AM) and printed electronics, such as cost-effectiveness, scalability, non-contact printing, and the flexibility for ad-hoc customization. However, some challenges such as stable jetting states and defined printing zone still needs attention. Data driven modeling such as machine/deep learning (ML/DL) as a predictive methodology has proven to reduce the experimental cost and workload in AM for low-viscosity inks. However, there is an oversight in ML extension to high-viscosity inks due to some inherit challenges such as irregular shape formation, and adhesiveness. Therefore, this study is focused on the prediction of jetting states and defining the printing zone for three-dimensional (3D) inkjet printing of high-viscosity ink. The experimental data is comprised of equipment parameter settings, material properties, and camera-captured features. The jetting behavior is recorded with a high-speed camera and carefully categorized into five classes: <em>no jetting, orifice adhesion, droplet jetting, orifice tail</em>, and <em>beads hanging</em>. A robust and efficient high-viscosity 3D printing U-Net (HV3DP-UNet) model is proposed, that achieved the jetting state and printing zone prediction accuracy of 97.98% and 100% respectively. For the fair comparison, three traditional ML and two more DL models are tested and analyzed in detail. The robustness and efficacy of the proposed model is supplemented with four performance metrics, i.e., accuracy, precision, recall and f1-score. The models’ efficacy has been proved by achieving improved results on the public dataset, the proposed model has achieved overall prediction accuracy of 92.95%. The presented data-driven approach serves as a systematic framework for enhancing quality of inkjet-based 3D printing utilizing high-viscosity ink.</div></div>","PeriodicalId":54589,"journal":{"name":"Precision Engineering-Journal of the International Societies for Precision Engineering and Nanotechnology","volume":"92 ","pages":"Pages 63-76"},"PeriodicalIF":3.5,"publicationDate":"2024-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143176194","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-11-29DOI: 10.1016/j.precisioneng.2024.11.016
Tao Zhu , Kangsen Li , Feng Gong
Hot embossing forming technology is a key technology for fabricating micro-nanostructures on optical glass, providing a process for efficient, large-scale, and economical production of optical glass components with excellent optical performance. The process uses coated mold with micro-nanostructures to hot emboss optical glass at high temperatures. However, the intricate and unpredictable flow and deformation behavior of viscoelastic glass in the thermodynamic field presents challenges to researchers. Therefore, this paper begins with an evaluative review of the adhesion and friction effects of glass on different mold and coating materials. Based on this foundation, the paper comprehensively summarizes both theoretical and applied advanced studies on the filling and flow deformation mechanisms of viscoelastic glass during molding and the quality of the final molded product. Then, the development of high-precision prediction models and molding parameter control systems is proposed for the future establishment of an integrated study framework that can predict glass flow deformation and to facilitate the efficient filling and accurate replication of micro-nanostructures. Finally, after summarizing the current research of the hot-rolled embossing for optical polymer, this paper pioneeringly proposes the unresolved critical challenges and related solutions of hot-rolled embossing for optical glass, setting the course for future research efforts in the emerging field of advanced hot-rolled embossing technologies.
{"title":"Advances in hot embossing technology for optical glass micro-nanostructures: A review","authors":"Tao Zhu , Kangsen Li , Feng Gong","doi":"10.1016/j.precisioneng.2024.11.016","DOIUrl":"10.1016/j.precisioneng.2024.11.016","url":null,"abstract":"<div><div>Hot embossing forming technology is a key technology for fabricating micro-nanostructures on optical glass, providing a process for efficient, large-scale, and economical production of optical glass components with excellent optical performance. The process uses coated mold with micro-nanostructures to hot emboss optical glass at high temperatures. However, the intricate and unpredictable flow and deformation behavior of viscoelastic glass in the thermodynamic field presents challenges to researchers. Therefore, this paper begins with an evaluative review of the adhesion and friction effects of glass on different mold and coating materials. Based on this foundation, the paper comprehensively summarizes both theoretical and applied advanced studies on the filling and flow deformation mechanisms of viscoelastic glass during molding and the quality of the final molded product. Then, the development of high-precision prediction models and molding parameter control systems is proposed for the future establishment of an integrated study framework that can predict glass flow deformation and to facilitate the efficient filling and accurate replication of micro-nanostructures. Finally, after summarizing the current research of the hot-rolled embossing for optical polymer, this paper pioneeringly proposes the unresolved critical challenges and related solutions of hot-rolled embossing for optical glass, setting the course for future research efforts in the emerging field of advanced hot-rolled embossing technologies.</div></div>","PeriodicalId":54589,"journal":{"name":"Precision Engineering-Journal of the International Societies for Precision Engineering and Nanotechnology","volume":"92 ","pages":"Pages 141-166"},"PeriodicalIF":3.5,"publicationDate":"2024-11-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143176765","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
To address the critical demand for on-machine metrology (OMM) in precision optics fabrication, a unique dual-mode OMM system has been developed. By integrating polarization-based snapshot motionless phase shifting, this OMM system enables the measurement of both surface form and roughness under laser interferometry mode and LED interference microscopy mode. Its compact and dual-mode design makes it ideal for on-machine tool alignment within single-point diamond turning (SPDT) machines, without the need to remove parts. To enhance its OMM capabilities, a defocus-model-based least square (L2) regression fitting algorithm and a convex-hull-based L2 regression are proposed to achieve precise retrieval of deviations in X and Y axes with robustness. Additionally, a high-precision calibration method for testing system misalignment, based on the Zernike high-order approximation model, is applied to relax the OMM system alignment requirements. As a result, rapid tool alignment is achieved without stringent alignment needs. The proposed OMM eliminates the necessity for offline metrology feedback during the tool alignment process and increases process efficiency by at least 50 %. Furthermore, it eliminates errors caused by removing, repositioning, and rebalancing the part, offering a novel alternative solution to address the critical demand for SPDT tool alignment and surface characterization.
{"title":"Dual-mode on-machine metrology for SPDT tool alignment","authors":"Wenjun Kang, Yihan Wang, Hongzhang Ma, Daodang Wang, Rongguang Liang","doi":"10.1016/j.precisioneng.2024.11.015","DOIUrl":"10.1016/j.precisioneng.2024.11.015","url":null,"abstract":"<div><div>To address the critical demand for on-machine metrology (OMM) in precision optics fabrication, a unique dual-mode OMM system has been developed. By integrating polarization-based snapshot motionless phase shifting, this OMM system enables the measurement of both surface form and roughness under laser interferometry mode and LED interference microscopy mode. Its compact and dual-mode design makes it ideal for on-machine tool alignment within single-point diamond turning (SPDT) machines, without the need to remove parts. To enhance its OMM capabilities, a defocus-model-based least square (L2) regression fitting algorithm and a convex-hull-based L2 regression are proposed to achieve precise retrieval of deviations in X and Y axes with robustness. Additionally, a high-precision calibration method for testing system misalignment, based on the Zernike high-order approximation model, is applied to relax the OMM system alignment requirements. As a result, rapid tool alignment is achieved without stringent alignment needs. The proposed OMM eliminates the necessity for offline metrology feedback during the tool alignment process and increases process efficiency by at least 50 %. Furthermore, it eliminates errors caused by removing, repositioning, and rebalancing the part, offering a novel alternative solution to address the critical demand for SPDT tool alignment and surface characterization.</div></div>","PeriodicalId":54589,"journal":{"name":"Precision Engineering-Journal of the International Societies for Precision Engineering and Nanotechnology","volume":"92 ","pages":"Pages 101-110"},"PeriodicalIF":3.5,"publicationDate":"2024-11-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143176763","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-11-28DOI: 10.1016/j.precisioneng.2024.11.010
Qing He, Jiaxing Ning, Xu Liu, Qingying Li
It is challenging for phase-shifting profilometry to measure objects in motion on production lines due to two main issues. Firstly, the movement of the object causes a mismatch in its position across different fringe patterns. Additionally, there is a violation of the ideal phase shift between these fringe patterns. To address these problems, we propose a method that takes advantage of the known moving direction of objects on production lines. By aligning the isophase direction of fringe patterns with the known direction of the moving objects, our method essentially solves the well-known phase error problem caused by object motion. Furthermore, we have developed a projection and imaging technique to track the measured object that is covered with different fringe patterns. Both of the previously listed issues have been resolved in this manner. The proposed method is validated by comparisons with state-of-the-art methods, proving its simplicity, broader applicability, and improved measurement accuracy.
{"title":"Phase-shifting profilometry for 3D shape measurement of moving objects on production lines","authors":"Qing He, Jiaxing Ning, Xu Liu, Qingying Li","doi":"10.1016/j.precisioneng.2024.11.010","DOIUrl":"10.1016/j.precisioneng.2024.11.010","url":null,"abstract":"<div><div>It is challenging for phase-shifting profilometry to measure objects in motion on production lines due to two main issues. Firstly, the movement of the object causes a mismatch in its position across different fringe patterns. Additionally, there is a violation of the ideal phase shift between these fringe patterns. To address these problems, we propose a method that takes advantage of the known moving direction of objects on production lines. By aligning the isophase direction of fringe patterns with the known direction of the moving objects, our method essentially solves the well-known phase error problem caused by object motion. Furthermore, we have developed a projection and imaging technique to track the measured object that is covered with different fringe patterns. Both of the previously listed issues have been resolved in this manner. The proposed method is validated by comparisons with state-of-the-art methods, proving its simplicity, broader applicability, and improved measurement accuracy.</div></div>","PeriodicalId":54589,"journal":{"name":"Precision Engineering-Journal of the International Societies for Precision Engineering and Nanotechnology","volume":"92 ","pages":"Pages 30-38"},"PeriodicalIF":3.5,"publicationDate":"2024-11-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142759581","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-11-26DOI: 10.1016/j.precisioneng.2024.11.011
Jianzhou Chen , Zhifeng Liu , Chuanhai Chen , Baobao Qi , Jingjing Xu , Long Tao , Qiaobin Yan
The flexibility of joints has the major influence on the robot stiffness, which makes it limited in the field of precision and ultra-precision machining. How to ensure the end-effector stiffness of the robot has been one significant problem for the above application. To address this challenge, in this work, a rigid-flexible coupling simulation method is proposed for the robot, then based on the simulation, the robotic end-effector stiffness prediction model is established, which can be applied to the robotic trajectory planning to control its end-effector stiffness. In the simulation method, the rigid-flexible simulation model of the robot is established based on the torsional stiffness estimation of each joint and its global decomposition in multiple directions of robotic base coordinate system. During the stiffness modeling, the neural network theory is used to establish a mapping model between robotic pose and end-effector stiffness based on the sample data accumulated by simulations under different poses. In order to show the significance of this work, an application case to the trajectory planning problem is performed. The results analysis, indicates that the proposed algorithm can control the end-effector stiffness not less than the required value during the whole robotic operation.
{"title":"Robot stiffness modeling based on the rigid flexible coupling simulation and its application to trajectory planning","authors":"Jianzhou Chen , Zhifeng Liu , Chuanhai Chen , Baobao Qi , Jingjing Xu , Long Tao , Qiaobin Yan","doi":"10.1016/j.precisioneng.2024.11.011","DOIUrl":"10.1016/j.precisioneng.2024.11.011","url":null,"abstract":"<div><div>The flexibility of joints has the major influence on the robot stiffness, which makes it limited in the field of precision and ultra-precision machining. How to ensure the end-effector stiffness of the robot has been one significant problem for the above application. To address this challenge, in this work, a rigid-flexible coupling simulation method is proposed for the robot, then based on the simulation, the robotic end-effector stiffness prediction model is established, which can be applied to the robotic trajectory planning to control its end-effector stiffness. In the simulation method, the rigid-flexible simulation model of the robot is established based on the torsional stiffness estimation of each joint and its global decomposition in multiple directions of robotic base coordinate system. During the stiffness modeling, the neural network theory is used to establish a mapping model between robotic pose and end-effector stiffness based on the sample data accumulated by simulations under different poses. In order to show the significance of this work, an application case to the trajectory planning problem is performed. The results analysis, indicates that the proposed algorithm can control the end-effector stiffness not less than the required value during the whole robotic operation.</div></div>","PeriodicalId":54589,"journal":{"name":"Precision Engineering-Journal of the International Societies for Precision Engineering and Nanotechnology","volume":"92 ","pages":"Pages 77-89"},"PeriodicalIF":3.5,"publicationDate":"2024-11-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143176195","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-11-25DOI: 10.1016/j.precisioneng.2024.11.003
Lei Yuan , Mingxiang Ling , Jianhao Lai , Tingjun Zeng , Hao Xu , Xianmin Zhang
A novel three-stage displacement amplifying mechanism is proposed by integrating the lever-type, Scott-Russell and double-arm elliptical mechanisms with red blood cell inspired flexure hinges that well balances the displacement amplification ratio and main resonance frequency. Flexure hinges are loaded in tension and bending instead of compression and bending, which can be free from potential buckling problems due to the stress stiffening effects. The combination of the dynamic stiffness matrix method and the discrete-beam transfer matrix method is utilized to rapidly forecast the kinetostatic and dynamic performances of the proposed compliant amplifier, including the curved-axis flexure hinges with complex contour profiles. Then, the Pareto multi-objective optimization strategy, taking those key geometric parameters obtained by the sensitivity analysis into account, is represented based on NSGA-II and a linear frequency solution strategy to accelerate the calculation efficiency and parameter optimization iteration. Based on the application requirement, a point on the Pareto curve is chosen as the optimal configuration for operating conditions. At last, experiments of the piezoelectric compliant amplifier under two types of external mass loads are exhibited. A displacement amplification ratio of 12.2 and main resonance frequency of 1380.5 Hz are achieved for the piezoelectric compliant amplifier under no external mass load.
{"title":"Optimal design of a novel three-stage displacement amplifying mechanism with curved-axis flexure hinges","authors":"Lei Yuan , Mingxiang Ling , Jianhao Lai , Tingjun Zeng , Hao Xu , Xianmin Zhang","doi":"10.1016/j.precisioneng.2024.11.003","DOIUrl":"10.1016/j.precisioneng.2024.11.003","url":null,"abstract":"<div><div>A novel three-stage displacement amplifying mechanism is proposed by integrating the lever-type, Scott-Russell and double-arm elliptical mechanisms with red blood cell inspired flexure hinges that well balances the displacement amplification ratio and main resonance frequency. Flexure hinges are loaded in tension and bending instead of compression and bending, which can be free from potential buckling problems due to the stress stiffening effects. The combination of the dynamic stiffness matrix method and the discrete-beam transfer matrix method is utilized to rapidly forecast the kinetostatic and dynamic performances of the proposed compliant amplifier, including the curved-axis flexure hinges with complex contour profiles. Then, the Pareto multi-objective optimization strategy, taking those key geometric parameters obtained by the sensitivity analysis into account, is represented based on NSGA-II and a linear frequency solution strategy to accelerate the calculation efficiency and parameter optimization iteration. Based on the application requirement, a point on the Pareto curve is chosen as the optimal configuration for operating conditions. At last, experiments of the piezoelectric compliant amplifier under two types of external mass loads are exhibited. A displacement amplification ratio of 12.2 and main resonance frequency of 1380.5 Hz are achieved for the piezoelectric compliant amplifier under no external mass load.</div></div>","PeriodicalId":54589,"journal":{"name":"Precision Engineering-Journal of the International Societies for Precision Engineering and Nanotechnology","volume":"92 ","pages":"Pages 39-62"},"PeriodicalIF":3.5,"publicationDate":"2024-11-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143176753","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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