Pub Date : 2024-07-04DOI: 10.3390/machines12070455
Luz M. Tobar-Subía-Contento, Anthony Mandow, J. Gómez-de-Gabriel
The rapid development of wearable technologies is increasing research interest in on-body robotics, where relocatable robots can serve as haptic interfaces, support healthcare measurements, or assist with daily activities. However, on-body mobile robotics poses challenges in aspects such as stable locomotion and control. This article proposes a novel small robot design for moving on human limbs that consists of an open grasping mechanism with a spring linkage, where one side holds a pivoting differential drive base (PDDB) with two spherical rollers, and the other side holds an actuated roller for grasping and stabilization. The spherical rollers maintain contact at three points on the limb, optimizing stability with a minimal number of rollers and integrating DC motors within. The PDDB wheels (spherical rollers) enable directional changes on limb surfaces. The combination of the open mechanism, the PDDB, and the spherical rollers allows adaptability to diameter variations along the limb. Furthermore, the mechanism can be easily put on or removed at any point along the limb, eliminating the need to slip the robot over the hand or foot. The kinematic model for the proposed mechanism has been developed. A cascade control strategy is proposed with an outer loop for stable grasping and an inner loop for trajectory adjustments using PDDB roller velocities. An on-limb robot prototype has been built to test its applicability to human arms. Simulation and experimental results validate the design.
{"title":"Open On-Limb Robot Locomotion Mechanism with Spherical Rollers and Diameter Adaptation","authors":"Luz M. Tobar-Subía-Contento, Anthony Mandow, J. Gómez-de-Gabriel","doi":"10.3390/machines12070455","DOIUrl":"https://doi.org/10.3390/machines12070455","url":null,"abstract":"The rapid development of wearable technologies is increasing research interest in on-body robotics, where relocatable robots can serve as haptic interfaces, support healthcare measurements, or assist with daily activities. However, on-body mobile robotics poses challenges in aspects such as stable locomotion and control. This article proposes a novel small robot design for moving on human limbs that consists of an open grasping mechanism with a spring linkage, where one side holds a pivoting differential drive base (PDDB) with two spherical rollers, and the other side holds an actuated roller for grasping and stabilization. The spherical rollers maintain contact at three points on the limb, optimizing stability with a minimal number of rollers and integrating DC motors within. The PDDB wheels (spherical rollers) enable directional changes on limb surfaces. The combination of the open mechanism, the PDDB, and the spherical rollers allows adaptability to diameter variations along the limb. Furthermore, the mechanism can be easily put on or removed at any point along the limb, eliminating the need to slip the robot over the hand or foot. The kinematic model for the proposed mechanism has been developed. A cascade control strategy is proposed with an outer loop for stable grasping and an inner loop for trajectory adjustments using PDDB roller velocities. An on-limb robot prototype has been built to test its applicability to human arms. Simulation and experimental results validate the design.","PeriodicalId":509264,"journal":{"name":"Machines","volume":" 123","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-07-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141680307","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-07-04DOI: 10.3390/machines12070457
Shuai Wang, Yakun Zhang, Guofang Gong, Huayong Yang
The rapid and accurate control of air chamber pressure in slurry pressure balance (SPB) shield tunneling machines is crucial for establishing the balance between slurry pressure and soil and water pressure, ensuring the stability of the support face. A novel air chamber pressure control method based on nonlinear adaptive robust control (ARC) and using a pneumatic proportional three-way pressure-reducing valve is proposed in this paper. Firstly, an electric proportional control system for the air chamber pressure is developed. Secondly, a nonlinear state space model for the air chamber pressure regulation process is established. Utilizing experimental data from the SPB shield tunneling machine test bench, nonlinear adaptive identification is conducted through the nonlinear recursive least square algorithm. The results demonstrate the model’s effectiveness and accuracy. Then, a nonlinear ARC for air chamber pressure is designed based on the backstepping method, and its Lyapunov stability is proved. Finally, the feasibility and effectiveness of the controller designed in this paper is verified through simulation and experiments. The results demonstrate that the developed control system can compensate for the nonlinearity and disturbance in the air chamber pressure regulation process. It can achieve good transient and steady-state performance and has good robustness against uncertainty.
{"title":"The Development and Nonlinear Adaptive Robust Control of the Air Chamber Pressure Regulation System of a Slurry Pressure Balance Shield Tunneling Machine","authors":"Shuai Wang, Yakun Zhang, Guofang Gong, Huayong Yang","doi":"10.3390/machines12070457","DOIUrl":"https://doi.org/10.3390/machines12070457","url":null,"abstract":"The rapid and accurate control of air chamber pressure in slurry pressure balance (SPB) shield tunneling machines is crucial for establishing the balance between slurry pressure and soil and water pressure, ensuring the stability of the support face. A novel air chamber pressure control method based on nonlinear adaptive robust control (ARC) and using a pneumatic proportional three-way pressure-reducing valve is proposed in this paper. Firstly, an electric proportional control system for the air chamber pressure is developed. Secondly, a nonlinear state space model for the air chamber pressure regulation process is established. Utilizing experimental data from the SPB shield tunneling machine test bench, nonlinear adaptive identification is conducted through the nonlinear recursive least square algorithm. The results demonstrate the model’s effectiveness and accuracy. Then, a nonlinear ARC for air chamber pressure is designed based on the backstepping method, and its Lyapunov stability is proved. Finally, the feasibility and effectiveness of the controller designed in this paper is verified through simulation and experiments. The results demonstrate that the developed control system can compensate for the nonlinearity and disturbance in the air chamber pressure regulation process. It can achieve good transient and steady-state performance and has good robustness against uncertainty.","PeriodicalId":509264,"journal":{"name":"Machines","volume":" 40","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-07-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141678159","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
In response to the challenge of timely fault identification in the spindle bearings of machine tools operating in complex environments, this study proposes a method based on a combination of infrared imaging with an Informer and a CNN + Swin Transformer. The aim is to achieve real-time monitoring of bearing faults, precise fault localization, and classification of fault severity. To accomplish this, an angular contact ball bearing was chosen as the research subject. Initially, an infrared image dataset was constructed, encompassing various fault positions and degrees, by simulating different forms of bearing faults. Subsequently, an Informer-based bearing temperature prediction model was established to select faulty bearing data. Lastly, the faulty data were input into the CNN + Swin Transformer model for bearing fault recognition and classification. The results demonstrate that the Informer model accurately identifies abnormal temperature rises during bearing operation, effectively screening out faulty bearings. Under steady-state conditions, the model achieves a classification accuracy of 97.8%. Furthermore, after employing the Informer screening process, the proposed model exhibits a recognition precision of 98.9%, surpassing other models such as CNN, SVM, and Swin Transformer, which are mentioned in this paper.
{"title":"Bearing Health State Detection Based on Informer and CNN + Swin Transformer","authors":"Chunyang Liu, Weiwei Zou, Zhilei Hu, Hongyu Li, X. Sui, Xiqiang Ma, Fang Yang, Nan Guo","doi":"10.3390/machines12070456","DOIUrl":"https://doi.org/10.3390/machines12070456","url":null,"abstract":"In response to the challenge of timely fault identification in the spindle bearings of machine tools operating in complex environments, this study proposes a method based on a combination of infrared imaging with an Informer and a CNN + Swin Transformer. The aim is to achieve real-time monitoring of bearing faults, precise fault localization, and classification of fault severity. To accomplish this, an angular contact ball bearing was chosen as the research subject. Initially, an infrared image dataset was constructed, encompassing various fault positions and degrees, by simulating different forms of bearing faults. Subsequently, an Informer-based bearing temperature prediction model was established to select faulty bearing data. Lastly, the faulty data were input into the CNN + Swin Transformer model for bearing fault recognition and classification. The results demonstrate that the Informer model accurately identifies abnormal temperature rises during bearing operation, effectively screening out faulty bearings. Under steady-state conditions, the model achieves a classification accuracy of 97.8%. Furthermore, after employing the Informer screening process, the proposed model exhibits a recognition precision of 98.9%, surpassing other models such as CNN, SVM, and Swin Transformer, which are mentioned in this paper.","PeriodicalId":509264,"journal":{"name":"Machines","volume":" 69","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-07-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141680026","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-07-03DOI: 10.3390/machines12070454
Dragan S. Mihić, B. Brkovic, M. Terzic
In this paper, the methodology for designing an asymmetrical four-phase 8/6 switched reluctance motor (SRM) that achieves approximately constant output power over a wide speed range is described. In an asymmetrical 8/6 SRM, orthogonal phase pairs are different in terms of the pole width and number of turns. The main comparison criterion between the asymmetrical and symmetrical 8/6 SRM is the power-speed characteristic, obtained for a given rated RMS phase current of the symmetrical drive. The obtained results demonstrate that the asymmetrical 8/6 SRM allows the shape of the power-speed characteristic to be modified, thereby extending the constant power region well beyond that of the symmetrical configuration with the same rated power level. To make a fair comparison between the asymmetrical and symmetrical 8/6 SRM drives, the converter volt-ampere rating, machine volume, slot fill factor, and ohmic losses per phase are kept constant in all analyzed cases. For determination of the optimal control parameters and maximal drive performance for both designs, the appropriate SRM mathematical model and differential evolution algorithm are used. The applied model includes all substantial non-linearities and mutual coupling between phases. The simulation results are verified using a Finite Element Method (FEM)-based model in the Ansys Electronics 2020 R2 software package.
{"title":"Asymmetrical Four-Phase 8/6 Switched Reluctance Motor for a Wide Constant Power Region","authors":"Dragan S. Mihić, B. Brkovic, M. Terzic","doi":"10.3390/machines12070454","DOIUrl":"https://doi.org/10.3390/machines12070454","url":null,"abstract":"In this paper, the methodology for designing an asymmetrical four-phase 8/6 switched reluctance motor (SRM) that achieves approximately constant output power over a wide speed range is described. In an asymmetrical 8/6 SRM, orthogonal phase pairs are different in terms of the pole width and number of turns. The main comparison criterion between the asymmetrical and symmetrical 8/6 SRM is the power-speed characteristic, obtained for a given rated RMS phase current of the symmetrical drive. The obtained results demonstrate that the asymmetrical 8/6 SRM allows the shape of the power-speed characteristic to be modified, thereby extending the constant power region well beyond that of the symmetrical configuration with the same rated power level. To make a fair comparison between the asymmetrical and symmetrical 8/6 SRM drives, the converter volt-ampere rating, machine volume, slot fill factor, and ohmic losses per phase are kept constant in all analyzed cases. For determination of the optimal control parameters and maximal drive performance for both designs, the appropriate SRM mathematical model and differential evolution algorithm are used. The applied model includes all substantial non-linearities and mutual coupling between phases. The simulation results are verified using a Finite Element Method (FEM)-based model in the Ansys Electronics 2020 R2 software package.","PeriodicalId":509264,"journal":{"name":"Machines","volume":"214 2","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-07-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141681574","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-07-02DOI: 10.3390/machines12070452
Yanzhong He, Xiang Luo, Xingsong Wang
In this paper, the characteristics of special stamping process requirements and the shortcomings of existing application technology are studied. Through repeated motion simulation analysis and size optimization calculation, a kind of inertia-controlled molding press is proposed to make up for this technical vacancy. This paper first describes the working principle and structure scheme of the main transmission mechanism of the inertia-controlled molding press. With the help of Adams-View x64 2013, the main transmission mechanism is simulated and analyzed from the aspects of kinematics and dynamics, and a physical prototype is made to test the key reliability indexes of the main transmission mechanism. According to the test data, the static strength, stiffness, vibration characteristics, and dynamic characteristics of the 200 t inertia-controlled molding press are evaluated, which provides a reference for the design of this kind of machine tool.
本文研究了特种冲压工艺要求的特点和现有应用技术的不足。通过反复的运动仿真分析和尺寸优化计算，提出了一种惯性控制成型压力机来弥补这一技术空缺。本文首先介绍了惯性控制成型压力机主传动机构的工作原理和结构方案。借助 Adams-View x64 2013，从运动学、动力学等方面对主传动机构进行了仿真分析，并制作了实物样机，对主传动机构的关键可靠性指标进行了测试。根据测试数据，对 200 t 惯性控制成型压力机的静态强度、刚度、振动特性和动态特性进行了评估，为此类机床的设计提供了参考。
{"title":"Simulation Analysis and Key Performance Index for Experimental Verification of a New Type of Press Transmission Mechanism","authors":"Yanzhong He, Xiang Luo, Xingsong Wang","doi":"10.3390/machines12070452","DOIUrl":"https://doi.org/10.3390/machines12070452","url":null,"abstract":"In this paper, the characteristics of special stamping process requirements and the shortcomings of existing application technology are studied. Through repeated motion simulation analysis and size optimization calculation, a kind of inertia-controlled molding press is proposed to make up for this technical vacancy. This paper first describes the working principle and structure scheme of the main transmission mechanism of the inertia-controlled molding press. With the help of Adams-View x64 2013, the main transmission mechanism is simulated and analyzed from the aspects of kinematics and dynamics, and a physical prototype is made to test the key reliability indexes of the main transmission mechanism. According to the test data, the static strength, stiffness, vibration characteristics, and dynamic characteristics of the 200 t inertia-controlled molding press are evaluated, which provides a reference for the design of this kind of machine tool.","PeriodicalId":509264,"journal":{"name":"Machines","volume":"28 2","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-07-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141685460","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Traditional grinding, which is predominantly performed with a negative rake angle (NRA), can be transformed into grinding with a positive rake angle (PRA) by employing femtosecond pulsed laser technology to modify the apex angle of the grains to be less than 90°. This innovative approach aims to reduce grinding forces and grinding temperatures while improving the surface quality of typical hard-to-machine materials. To assess the performance of PRA single grain grinding and to investigate the underlying mechanisms, the finite element simulation software ABAQUS 6.14 was employed to model the grinding of Ti6Al4V titanium alloy with a single diamond abrasive grain. The dependence of grinding force and temperature in single grain grinding with a PRA or an NRA under different grinding parameters was studied and compared. PRA and NRA single diamond grain grinding experiments on Ti6Al4V alloy were carried out, with grinding forces measured using a dynamometer and compared with the simulation results. The grinding surface morphology and surface roughness were observed and measured, and a comparison was made between PRA and NRA grinding. The results indicated that in single diamond grain grinding, transforming to a PRA significantly enhances grinding performance, as evidenced by reduced grinding forces, lower temperatures, improved surface morphology, and decreased surface roughness. These findings suggest that PRA single diamond grain grinding offers substantial benefits for the precision machining of hard-to-machine materials, marking a step forward in optimizing surface finishes.
传统磨削主要以负前角 (NRA) 方式进行，而通过采用飞秒脉冲激光技术将磨粒顶角修改为小于 90°，可将传统磨削转变为正前角 (PRA) 磨削。这种创新方法旨在降低磨削力和磨削温度，同时提高典型难加工材料的表面质量。为了评估 PRA 单磨粒磨削的性能并研究其基本机理，我们采用有限元模拟软件 ABAQUS 6.14 建立了使用单个金刚石磨粒磨削 Ti6Al4V 钛合金的模型。研究并比较了在不同磨削参数下使用 PRA 或 NRA 进行单晶粒磨削时磨削力和温度的变化情况。对 Ti6Al4V 合金进行了 PRA 和 NRA 单金刚石磨粒磨削实验，使用测功机测量了磨削力，并与模拟结果进行了比较。对磨削表面形态和表面粗糙度进行了观察和测量，并对 PRA 和 NRA 磨削进行了比较。结果表明，在单金刚石晶粒磨削中，改用 PRA 能显著提高磨削性能，具体表现为磨削力降低、温度降低、表面形态改善和表面粗糙度降低。这些研究结果表明，PRA 单金刚石晶粒磨削为难加工材料的精密加工提供了巨大优势，标志着在优化表面光洁度方面又向前迈进了一步。
{"title":"Investigation of Single Grain Grinding of Titanium Alloy Using Diamond Abrasive Grain with Positive Rake Angle","authors":"Jiu Yin, Rushui Sun, Chuanbo Ming, Chang Chen, Shuai Zeng","doi":"10.3390/machines12070451","DOIUrl":"https://doi.org/10.3390/machines12070451","url":null,"abstract":"Traditional grinding, which is predominantly performed with a negative rake angle (NRA), can be transformed into grinding with a positive rake angle (PRA) by employing femtosecond pulsed laser technology to modify the apex angle of the grains to be less than 90°. This innovative approach aims to reduce grinding forces and grinding temperatures while improving the surface quality of typical hard-to-machine materials. To assess the performance of PRA single grain grinding and to investigate the underlying mechanisms, the finite element simulation software ABAQUS 6.14 was employed to model the grinding of Ti6Al4V titanium alloy with a single diamond abrasive grain. The dependence of grinding force and temperature in single grain grinding with a PRA or an NRA under different grinding parameters was studied and compared. PRA and NRA single diamond grain grinding experiments on Ti6Al4V alloy were carried out, with grinding forces measured using a dynamometer and compared with the simulation results. The grinding surface morphology and surface roughness were observed and measured, and a comparison was made between PRA and NRA grinding. The results indicated that in single diamond grain grinding, transforming to a PRA significantly enhances grinding performance, as evidenced by reduced grinding forces, lower temperatures, improved surface morphology, and decreased surface roughness. These findings suggest that PRA single diamond grain grinding offers substantial benefits for the precision machining of hard-to-machine materials, marking a step forward in optimizing surface finishes.","PeriodicalId":509264,"journal":{"name":"Machines","volume":"27 30","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-07-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141684573","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-07-02DOI: 10.3390/machines12070453
Albin Bajrami, Matteo Claudio Palpacelli
This study focuses on training a custom, small Convolutional Neural Network (CNN) using a limited dataset through data augmentation that is aimed at developing weights for subsequent fine-tuning on specific defects, namely improperly polished aluminum surfaces. The objective is to adapt the network for use in computationally restricted environments. The methodology involves using two computers—a low-performance PC for network creation and initial testing and a more powerful PC for network training using the Darknet framework—after which the network is transferred back to the initial low-performance PC. The results demonstrate that the custom lightweight network suited for a low-performance PC effectively performs object detection under the described conditions. These findings suggest that using tailored lightweight networks for recognizing specific types of defects is feasible and warrants further investigation to enhance the industrial defect detection processes in limited computational settings. This approach highlights the potential for deploying AI-driven quality control in environments with constrained hardware capabilities.
本研究的重点是通过数据扩增，使用有限的数据集训练一个定制的小型卷积神经网络（CNN），目的是开发权重，以便随后针对特定缺陷（即铝表面抛光不当）进行微调。目的是使网络适用于计算受限的环境。该方法包括使用两台计算机--一台低性能 PC 用于网络创建和初始测试，另一台更强大的 PC 用于使用 Darknet 框架进行网络训练--之后将网络传输回初始的低性能 PC。结果表明，在所述条件下，适合低性能 PC 的定制轻量级网络能有效地进行物体检测。这些研究结果表明，使用定制的轻量级网络识别特定类型的缺陷是可行的，值得进一步研究，以便在有限的计算环境中增强工业缺陷检测流程。这种方法凸显了在硬件能力有限的环境中部署人工智能驱动的质量控制的潜力。
{"title":"From Dataset Creation to Defect Detection: A Proposed Procedure for a Custom CNN Approach for Polishing Applications on Low-Performance PCs","authors":"Albin Bajrami, Matteo Claudio Palpacelli","doi":"10.3390/machines12070453","DOIUrl":"https://doi.org/10.3390/machines12070453","url":null,"abstract":"This study focuses on training a custom, small Convolutional Neural Network (CNN) using a limited dataset through data augmentation that is aimed at developing weights for subsequent fine-tuning on specific defects, namely improperly polished aluminum surfaces. The objective is to adapt the network for use in computationally restricted environments. The methodology involves using two computers—a low-performance PC for network creation and initial testing and a more powerful PC for network training using the Darknet framework—after which the network is transferred back to the initial low-performance PC. The results demonstrate that the custom lightweight network suited for a low-performance PC effectively performs object detection under the described conditions. These findings suggest that using tailored lightweight networks for recognizing specific types of defects is feasible and warrants further investigation to enhance the industrial defect detection processes in limited computational settings. This approach highlights the potential for deploying AI-driven quality control in environments with constrained hardware capabilities.","PeriodicalId":509264,"journal":{"name":"Machines","volume":"32 44","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-07-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141685555","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-06-04DOI: 10.3390/machines12060386
Mengdi Xu, Yunfei Ge, Xianbin Du, Zhaohong Meng
The vibration of the tires significantly impacts a vehicle’s ride comfort and noise level; however, the current analysis of tire vibration characteristics often involves excessive simplification in their models, leading to a reduction in model accuracy. To analyze the tire vibrational properties and the influence of its design and service conditions, a combined modeling technology was developed to construct a three-dimensional (3D) finite element model of a 205/55R16 specification radial tire with intricate tread patterns. The accuracy and reliability of the simulation model was verified through vibration modal tests. Based on the vibration mode theory, the Lanczos method provided by ABAQUS was adopted to analyze the modal characteristics of the tire under free inflation and grounded conditions, and the effects of different inflation pressures, loads, operating conditions, and belt cord angles on the tire vibration characteristics were analyzed. The results indicate that grounding constraints will suppress the low order radial modal frequency of the tire and enhance the lateral modal frequency. The higher the order of the tire vibration mode, the greater the impact of inflation pressure. As the operating conditions change, the modal frequencies of all directions have the same trend of change, and as the ground load increases, the tire is prone to misalignment at lower lateral frequencies. The radial and lateral grounding modes of the tire are slightly affected by the change of the cord angle in the belt layer, but the circumferential grounding frequency decreases as the belt layer angle increases. These research findings offer a crucial foundation for the structural design of complex tread pattern tires, and also serve as a reference for addressing vibration and comfort issues encountered in the tire matching process.
{"title":"Analysis of Vibration Characteristics and Influencing Factors of Complex Tread Pattern Tires Based on Finite Element Method","authors":"Mengdi Xu, Yunfei Ge, Xianbin Du, Zhaohong Meng","doi":"10.3390/machines12060386","DOIUrl":"https://doi.org/10.3390/machines12060386","url":null,"abstract":"The vibration of the tires significantly impacts a vehicle’s ride comfort and noise level; however, the current analysis of tire vibration characteristics often involves excessive simplification in their models, leading to a reduction in model accuracy. To analyze the tire vibrational properties and the influence of its design and service conditions, a combined modeling technology was developed to construct a three-dimensional (3D) finite element model of a 205/55R16 specification radial tire with intricate tread patterns. The accuracy and reliability of the simulation model was verified through vibration modal tests. Based on the vibration mode theory, the Lanczos method provided by ABAQUS was adopted to analyze the modal characteristics of the tire under free inflation and grounded conditions, and the effects of different inflation pressures, loads, operating conditions, and belt cord angles on the tire vibration characteristics were analyzed. The results indicate that grounding constraints will suppress the low order radial modal frequency of the tire and enhance the lateral modal frequency. The higher the order of the tire vibration mode, the greater the impact of inflation pressure. As the operating conditions change, the modal frequencies of all directions have the same trend of change, and as the ground load increases, the tire is prone to misalignment at lower lateral frequencies. The radial and lateral grounding modes of the tire are slightly affected by the change of the cord angle in the belt layer, but the circumferential grounding frequency decreases as the belt layer angle increases. These research findings offer a crucial foundation for the structural design of complex tread pattern tires, and also serve as a reference for addressing vibration and comfort issues encountered in the tire matching process.","PeriodicalId":509264,"journal":{"name":"Machines","volume":"8 10","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-06-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141266135","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-06-04DOI: 10.3390/machines12060385
Hyogon Kim, Ji-Hyun Park, Jong-Chan Kim, Jeong-Hwan Hwang, Jeong-Woo Park, In-Gyu Park, Hyojun Lee, Kyoungseok Noh, Young-Ho Choi, Jin-Ho Suh
The construction industry is a challenging field for the application of robots. In particular, bridge construction, which involves many tasks at great heights, makes it difficult to implement robots. To construct a bridge, it is necessary to build numerous piers that can support the bridge deck. Pier construction involves a series of tasks including rebar connection, formwork installation, concrete pouring, formwork dismantling, and formwork reinstallation. These activities require working at heights, presenting a significant risk of falls. If bridge construction could be performed remotely using robots instead of relying on human labor, it would greatly contribute to the safety of bridge construction. This paper proposes a multi-robot system capable of remote operation and automation for rebar structure connection, concrete pouring, and concrete vibrating tasks in pier construction. The proposed multi-robot system for pier construction is composed of three robot systems. Each robot system consists of a robot arm mounted on a mobile robot that can move along rails. And to apply the proposed system to a construction site, it is essential to implement a compliance control algorithm that adapts to external forces. In this paper, we propose an admittance control that takes into account the weight of the tool for the compliance control of the proposed robot, which performs tasks by switching between various construction tools of different weights. Furthermore, we propose a synchronization control method for the multi-robot system to connect reinforcing structures. We validated the proposed algorithm through simulation. Furthermore, we developed a prototype of the proposed system to verify the feasibility of the suggested hardware design and control.
{"title":"Development of a Multi-Robot System for Pier Construction","authors":"Hyogon Kim, Ji-Hyun Park, Jong-Chan Kim, Jeong-Hwan Hwang, Jeong-Woo Park, In-Gyu Park, Hyojun Lee, Kyoungseok Noh, Young-Ho Choi, Jin-Ho Suh","doi":"10.3390/machines12060385","DOIUrl":"https://doi.org/10.3390/machines12060385","url":null,"abstract":"The construction industry is a challenging field for the application of robots. In particular, bridge construction, which involves many tasks at great heights, makes it difficult to implement robots. To construct a bridge, it is necessary to build numerous piers that can support the bridge deck. Pier construction involves a series of tasks including rebar connection, formwork installation, concrete pouring, formwork dismantling, and formwork reinstallation. These activities require working at heights, presenting a significant risk of falls. If bridge construction could be performed remotely using robots instead of relying on human labor, it would greatly contribute to the safety of bridge construction. This paper proposes a multi-robot system capable of remote operation and automation for rebar structure connection, concrete pouring, and concrete vibrating tasks in pier construction. The proposed multi-robot system for pier construction is composed of three robot systems. Each robot system consists of a robot arm mounted on a mobile robot that can move along rails. And to apply the proposed system to a construction site, it is essential to implement a compliance control algorithm that adapts to external forces. In this paper, we propose an admittance control that takes into account the weight of the tool for the compliance control of the proposed robot, which performs tasks by switching between various construction tools of different weights. Furthermore, we propose a synchronization control method for the multi-robot system to connect reinforcing structures. We validated the proposed algorithm through simulation. Furthermore, we developed a prototype of the proposed system to verify the feasibility of the suggested hardware design and control.","PeriodicalId":509264,"journal":{"name":"Machines","volume":"3 8","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-06-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141266090","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-06-04DOI: 10.3390/machines12060384
Gustavo Garbelini de Menezes, Narco Afonso Ravazzoli Maciejewski, Elissa Soares de Carvalho, T. Bazzo
This paper sets forth a thorough procedure to design surface-mounted permanent magnet synchronous generators. Since synchronous generators generate the majority of electrical energy, their relevance in society nowadays is substantial. As a consequence, the methodology to design these electrical machines also holds great importance. However, even though a considerable amount of works addresses the matter, it is difficult to find a complete and thoroughly explained design procedure. The proposed method is based on analytical equations to fully consider PM generator fundamentals with a few simplifications, which implies in a considerable number of design equations and parameters. Differently from most papers on the design of PM synchronous generators, a significant level of detail and explanation is presented, all design choices are discussed, and the suggested ranges for the design parameters are shown. This results in a straightforward procedure that allows non-experienced designers to easily replicate the results and effectively enhance the comprehension of permanent magnet synchronous machines, and provides a guideline for researchers from other fields who may need to understand and perform a synchronous generator design. To show the effectiveness of the proposed design procedure, a PM generator is designed, and the results are compared with a finite element simulation, showing good accuracy.
{"title":"A Thorough Procedure to Design Surface-Mounted Permanent Magnet Synchronous Generators","authors":"Gustavo Garbelini de Menezes, Narco Afonso Ravazzoli Maciejewski, Elissa Soares de Carvalho, T. Bazzo","doi":"10.3390/machines12060384","DOIUrl":"https://doi.org/10.3390/machines12060384","url":null,"abstract":"This paper sets forth a thorough procedure to design surface-mounted permanent magnet synchronous generators. Since synchronous generators generate the majority of electrical energy, their relevance in society nowadays is substantial. As a consequence, the methodology to design these electrical machines also holds great importance. However, even though a considerable amount of works addresses the matter, it is difficult to find a complete and thoroughly explained design procedure. The proposed method is based on analytical equations to fully consider PM generator fundamentals with a few simplifications, which implies in a considerable number of design equations and parameters. Differently from most papers on the design of PM synchronous generators, a significant level of detail and explanation is presented, all design choices are discussed, and the suggested ranges for the design parameters are shown. This results in a straightforward procedure that allows non-experienced designers to easily replicate the results and effectively enhance the comprehension of permanent magnet synchronous machines, and provides a guideline for researchers from other fields who may need to understand and perform a synchronous generator design. To show the effectiveness of the proposed design procedure, a PM generator is designed, and the results are compared with a finite element simulation, showing good accuracy.","PeriodicalId":509264,"journal":{"name":"Machines","volume":"12 11","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-06-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141266495","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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