Machines最新文献_第3页

A Digital Twin-Based Adaptive Height Control for a Shearer 基于数字双胞胎的剪毛机自适应高度控制装置

Machines Pub Date : 2024-07-07 DOI: 10.3390/machines12070460

Xiusong You, Yinan Guo, Bing Miao, Shirong Ge

{"title":"A Digital Twin-Based Adaptive Height Control for a Shearer","authors":"Xiusong You, Yinan Guo, Bing Miao, Shirong Ge","doi":"10.3390/machines12070460","DOIUrl":"https://doi.org/10.3390/machines12070460","url":null,"abstract":"The shearer is an important component of the smart mining workface, and its effective control is a key aspect that guarantees safe and high-efficient production in coal mines. To address the issue of autonomous height adjustment during the shearer’s cutting process, a self-adaptive speed control method driven by digital twin technology is proposed. A digital twin-based control architecture for the shearer is first established, which consists of physical and the corresponding virtual entities, as well as reality–virtual interaction between them. Based on the mathematic model formulated for height adjustment system of the shearer, an adaptive fuzzy sliding mode controller (AFSMC) with the displacement estimation is designed for the virtual entity, with the purpose of guiding the operation of the corresponding physical entity. Simulation experiments on MATLAB compares the control performance among the proposed method and four comparative ones, including PID controller, integral sliding mode controller (ISMC), feedback linearization controller (FLC), and fuzzy sliding mode controller (FSMC). The experimental results confirm the effectiveness of the proposed AFSMC. More specifically, its steady-state error is 0.024, the maximum absolute control input is 8.43, and the settling time is 1.74 s. This also proves that the digital twin-based control method enables the precise adaptive height adjustment of the shearer, providing potential reference for the intelligent development of a smart mining workface.","PeriodicalId":509264,"journal":{"name":"Machines","volume":" 9","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-07-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141671238","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}

引用次数: 0

Accuracy Analysis of Complex Transmission System with Distributed Tooth Profile Errors 具有分布式齿形误差的复杂传动系统的精度分析

Machines Pub Date : 2024-07-06 DOI: 10.3390/machines12070459

Min Zhang, Zhijing Zhang, Jian Xiong, Xiao Chen

{"title":"Accuracy Analysis of Complex Transmission System with Distributed Tooth Profile Errors","authors":"Min Zhang, Zhijing Zhang, Jian Xiong, Xiao Chen","doi":"10.3390/machines12070459","DOIUrl":"https://doi.org/10.3390/machines12070459","url":null,"abstract":"Tooth profile errors are the internal excitations that cause gear meshing errors, which are critical error factors affecting gear transmission accuracy. In existing studies, it is usually regarded as a constant or random distribution function. However, the actual machined tooth profile error is not a constant, so this estimation is inconsistent with the actual situation, resulting in an inaccurate evaluation of transmission accuracy. This paper proposes a method for representing tooth profile errors using distribution errors (including systematic and random errors), and a mathematical model of distributed tooth profile errors is presented. The contact stresses of the complex transmission system were compared with those obtained by formulas, proving that tooth profile errors increase contact stress. A method for calculating gear meshing error is proposed to evaluate the actual output accuracy of the complex transmission system. Compared with the test, the output accuracy is reduced by 13.8% under the temperature environment and distributed tooth profile errors. The proposed methods can accurately predict the transmission accuracy of precision transmission systems at the design stage and provide theoretical support for reducing systematic and random errors at the gear machining stage.","PeriodicalId":509264,"journal":{"name":"Machines","volume":" 15","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-07-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141672919","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}

引用次数: 0

Research on Vibration Characteristics of Bearingless Motorized Spindles Based on Multibody Dynamics 基于多体动力学的无轴承电动主轴振动特性研究

Machines Pub Date : 2024-07-05 DOI: 10.3390/machines12070458

Jie Meng, Lihong He, Jianan Yang, Shuang Liu

{"title":"Research on Vibration Characteristics of Bearingless Motorized Spindles Based on Multibody Dynamics","authors":"Jie Meng, Lihong He, Jianan Yang, Shuang Liu","doi":"10.3390/machines12070458","DOIUrl":"https://doi.org/10.3390/machines12070458","url":null,"abstract":"During the service process of a bearingless motorized spindle (BLMS), its parameters change with both time and external conditions, leading to a decrease in the accuracy of the motorized spindle. Therefore, it is difficult to accurately describe the dynamic performance of a motorized spindle during its actual operation using deterministic parameters. In this paper, the interactions between the thermal deformation and vibration of a motorized spindle are explored. A dynamic model of the motorized spindle based on multibody dynamics and time-varying parameters is established, and a solution method for the dynamic model with uncertain parameters is investigated. Firstly, the reasons for the vibration in the BLMS are analyzed, and the influences of thermal deformation on the thermal eccentricity and inhomogeneous air gap of the BLMS are studied. A vibration model of the BLMS is established and solved to acquire the radial vibration displacement. Secondly, a discrete multibody dynamics model of the BLMS is built, and the center trajectory of the motorized spindle is attained by solving the multibody dynamics model. A prototype experimental platform of the BLMS is designed, and vibration tests are carried out. The experimental results show that the vibration amplitude of the BLMS increases with the running time and the maximum displacement exhibits a large deviation from the simulation results using the determined parameters, while there is a small deviation from the simulation results using uncertain parameters; this indicates that the solution of the multibody dynamics model of the BLMS described by uncertain parameters is closer to the experimental data. These research findings can provide a reference for the optimized design of BLMSs.","PeriodicalId":509264,"journal":{"name":"Machines","volume":" 4","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-07-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141675751","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}

引用次数: 0

Open On-Limb Robot Locomotion Mechanism with Spherical Rollers and Diameter Adaptation 带球形滚轮和直径适应性的开放式肢上机器人运动机构

Machines Pub Date : 2024-07-04 DOI: 10.3390/machines12070455

Luz M. Tobar-Subía-Contento, Anthony Mandow, J. Gómez-de-Gabriel

{"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}

引用次数: 0

The Development and Nonlinear Adaptive Robust Control of the Air Chamber Pressure Regulation System of a Slurry Pressure Balance Shield Tunneling Machine 泥浆压力平衡盾构掘进机气室压力调节系统的开发与非线性自适应鲁棒控制

Machines Pub Date : 2024-07-04 DOI: 10.3390/machines12070457

Shuai Wang, Yakun Zhang, Guofang Gong, Huayong Yang

{"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}

引用次数: 0

Bearing Health State Detection Based on Informer and CNN + Swin Transformer 基于 Informer 和 CNN + Swin 变换器的轴承健康状态检测

Machines Pub Date : 2024-07-04 DOI: 10.3390/machines12070456

Chunyang Liu, Weiwei Zou, Zhilei Hu, Hongyu Li, X. Sui, Xiqiang Ma, Fang Yang, Nan Guo

{"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}

引用次数: 0

Asymmetrical Four-Phase 8/6 Switched Reluctance Motor for a Wide Constant Power Region 用于宽恒功率区域的非对称四相 8/6 开关磁阻电机

Machines Pub Date : 2024-07-03 DOI: 10.3390/machines12070454

Dragan S. Mihić, B. Brkovic, M. Terzic

{"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}

引用次数: 0

Simulation Analysis and Key Performance Index for Experimental Verification of a New Type of Press Transmission Mechanism 新型压力机传动机构的仿真分析和关键性能指标实验验证

Machines Pub Date : 2024-07-02 DOI: 10.3390/machines12070452

Yanzhong He, Xiang Luo, Xingsong Wang

引用次数: 0

Investigation of Single Grain Grinding of Titanium Alloy Using Diamond Abrasive Grain with Positive Rake Angle 使用正耙角金刚石磨粒对钛合金进行单粒磨削的研究

Machines Pub Date : 2024-07-02 DOI: 10.3390/machines12070451

Jiu Yin, Rushui Sun, Chuanbo Ming, Chang Chen, Shuai Zeng

{"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}

引用次数: 0

From Dataset Creation to Defect Detection: A Proposed Procedure for a Custom CNN Approach for Polishing Applications on Low-Performance PCs 从数据集创建到缺陷检测：低性能 PC 上抛光应用的定制 CNN 方法拟议流程

Machines Pub Date : 2024-07-02 DOI: 10.3390/machines12070453

Albin Bajrami, Matteo Claudio Palpacelli

{"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}

引用次数: 0