Machines

28 pages, 2593 KiB

Open AccessArticle

Dynamics Modeling and Suspension Parameters Optimization of Vehicle System Based on Reduced Multibody System Transfer Matrix Method

by Shaoheng Hu, Xiaoting Rui, Junjie Gu and Xizhe Zhang

Machines 2025, 13(2), 116; https://doi.org/10.3390/machines13020116 - 2 Feb 2025

Abstract

This study introduces an innovative vehicle-modeling framework based on the Reduced Multibody System Transfer Matrix Method, incorporating wheel–ground contact and friction to analyze dynamic performance metrics, including vertical acceleration, suspension deflection, and angular acceleration. The model is applied to simulate vehicle behavior at [...] Read more.

This study introduces an innovative vehicle-modeling framework based on the Reduced Multibody System Transfer Matrix Method, incorporating wheel–ground contact and friction to analyze dynamic performance metrics, including vertical acceleration, suspension deflection, and angular acceleration. The model is applied to simulate vehicle behavior at 40 km/h on Class D road conditions. To enhance dynamic characteristics, suspension parameters were optimized using the NSGA-II algorithm. The optimization process achieved significant reductions in vertical acceleration (24.12%), suspension deflection (25.98%), and angular acceleration (4.93%). The Pareto frontier facilitated the selection of a representative solution that balances smoothness, stability, and suspension performance. Frequency, PSD, and RMS analyses were performed under different road conditions and speeds to verify the robustness of the optimization results. The application of the transfer matrix method is extended to vehicle suspension modeling and optimization, offering valuable insights into improving ride comfort and stability. Additionally, it highlights the effectiveness of advanced multi-objective optimization techniques in improving vehicle dynamics and provides a robust methodology for practical applications. Full article

(This article belongs to the Section Vehicle Engineering)

13 pages, 4562 KiB

Open AccessArticle

Tool Condition Monitoring Model Based on DAE–SVR

by Xiaoning Sun, Zhifeng Yang, Maojin Xia, Min Xia, Changfu Liu, Yang Zhou and Yuquan Guo

Machines 2025, 13(2), 115; https://doi.org/10.3390/machines13020115 - 1 Feb 2025

Abstract

Cutting tools are executive components in metal processing, and tool wear directly affects the quality of the workpiece and processing efficiency; monitoring the change in its state is crucial to avoid accidents and ensure the safety of workers. The traditional monitoring model cannot [...] Read more.

Cutting tools are executive components in metal processing, and tool wear directly affects the quality of the workpiece and processing efficiency; monitoring the change in its state is crucial to avoid accidents and ensure the safety of workers. The traditional monitoring model cannot compress a large amount of cutting data effectively, failing to obtain reliable feature data, and there are some defects in generalization ability and monitoring accuracy. For this purpose, this article takes milling cutters as the research object, and it integrates signals from force sensors, vibration sensors, and acoustic emission sensors, combining the advantages of the denoising autoencoder (DAE) model in data compression and the high monitoring accuracy of the support vector regression (SVR) model, to establish a tool wear monitoring model based on DAE–SVR. The results show that compared with traditional DAE and SVR models in multiple datasets, the maximum improvement in monitoring performance (MAE) is 43.58%. Full article

(This article belongs to the Section Machines Testing and Maintenance)

29 pages, 2886 KiB

Open AccessArticle

Design and Discrete Element (DEM) Simulation Analysis of Grassland Ecological Cleaning and Restoration Vehicle

by Lvfa Yin, Anfu Guo, Chang Liu, Minghui Guo, Dechao Yang, Xianxiang Gao and Hailong Wu

Machines 2025, 13(2), 114; https://doi.org/10.3390/machines13020114 - 30 Jan 2025

Abstract

To reduce the weight of the grassland ecological restoration vehicle disk brush, force analysis and topology optimization are carried out to reduce the weight of the disk brush by 55.43%. Then, the study found that the vehicle speed and the rotational speed of [...] Read more.

To reduce the weight of the grassland ecological restoration vehicle disk brush, force analysis and topology optimization are carried out to reduce the weight of the disk brush by 55.43%. Then, the study found that the vehicle speed and the rotational speed of the disk brush have an effect on the trajectory of garbage throwing, and the relationship between the two needs to be coordinated. The sweeping effect works best when the speed ratio coefficient is greater than 1.826, which can be found by matching the motion trajectory equation with the speed ratio coefficient λ. Based on the discrete element method (DEM), it is verified that when the rotational speed is 90 r/min and the vehicle speed is 10 km/h, the sweeping effect is the best, and the influence on plants is minimized. Finally, the seeding effect of grass seeds was verified by a three-factor three-level orthogonal experiment. The results showed that high rotational speed and multiple slots could reduce the row spacing of seeding, while higher speed increased the row spacing of seeding. When the rotational speed of the seed-displacement disk was 50 r/min, the number of slots was 24, and the vehicle speed was 15 km/h, the seed displacement reached the maximum, and the row spacing was in line with the reasonable seeding requirements of ryegrass. The experimental results provide technical support for similar grassland cleaning and restoration vehicles in the future. Full article

(This article belongs to the Section Machine Design and Theory)

33 pages, 11404 KiB

Open AccessReview

Review on Key Development of Magnetic Bearings

by Tong Wu and Weiyu Zhang

Machines 2025, 13(2), 113; https://doi.org/10.3390/machines13020113 - 30 Jan 2025

Abstract

A magnetic suspension bearing is a device that suspends the rotating shaft in a balanced position by magnetic force, thereby eliminating the friction between the rotor and the stator. Different from traditional bearing support methods, magnetic bearings show significant advantages in terms of [...] Read more.

A magnetic suspension bearing is a device that suspends the rotating shaft in a balanced position by magnetic force, thereby eliminating the friction between the rotor and the stator. Different from traditional bearing support methods, magnetic bearings show significant advantages in terms of speed, accuracy, and loss. Because there is no contact, magnetic bearings enable high-speed operation, precise control, and zero friction. Magnetic bearings, with their excellent performance, are widely applied in fields such as industrial production, flywheel energy storage, and aerospace. However, with the continuous growth of the demand for high-performance bearings and the deepening of the concept of low-carbon and environmental protection, breakthroughs in the key technologies of magnetic bearings are urgently needed. In this paper, relevant research on magnetic bearings is summarized. Magnetic bearings are classified according to the different ways in which they generate suspension forces. Research on the topological structure design, mathematical modeling, and control strategies of the magnetic bearing system is covered. The aim is to provide readers and researchers with a comprehensive overview of the key technologies of magnetic bearings from a new perspective. Full article

(This article belongs to the Section Electromechanical Energy Conversion Systems)

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23 pages, 8351 KiB

Open AccessArticle

Event Knowledge Graph for a Knowledge-Based Design Process Model for Additive Manufacturing

by Chen Guohui, Auwal Haruna, Chen Youze, Li Lunyong, Khandaker Noman, Yongbo Li and K. Eliker

Machines 2025, 13(2), 112; https://doi.org/10.3390/machines13020112 - 30 Jan 2025

Abstract

Additive manufacturing (AM) technology is gaining acceptance as a strategic manufacturing technique for allowing new product development. Due to ongoing process improvement, design for AM (DFAM) has become a major issue in harnessing AM’s production and development possibilities to achieve design freedom. The [...] Read more.

Additive manufacturing (AM) technology is gaining acceptance as a strategic manufacturing technique for allowing new product development. Due to ongoing process improvement, design for AM (DFAM) has become a major issue in harnessing AM’s production and development possibilities to achieve design freedom. The classical design process model does not encompass all the knowledge available to take advantage of design freedom. Therefore, a conceptual and in-depth analysis of design alternatives is necessary to determine the manufacturing process. As a result, this research proposed a design process model for a DFAM to attain design freedom with a unique approach and resource selection steps for fused deposition modeling (FDM) that uses an information model based on evolving knowledge and addressing the challenges. The proposed design process model uses an event knowledge graph (EKG) to outline the product manufacturability from the perspective of DFAM limitations. Event-based knowledge representation provides causality information for knowledge-based reasoning in causality analysis tasks. A relationship-aware mechanism is then used to express events on the graph that are directed from entities to occurrences to efficiently extract the most relevant details. Thus, this implements a step-by-step approach to process and resource specifications during the design stage. Consequently, it offers a comprehensive learning approach for establishing and modeling intrinsic relationships to attain flexibility and design freedom. The efficacy and feasibility of the proposed approach are verified by using an application case study of an intake system based on the airflow sensing rate and controls how much air is fed into the engine. Full article

31 pages, 2117 KiB

Open AccessReview

Active Disturbance Rejection Control—New Trends in Agricultural Cybernetics in the Future: A Comprehensive Review

by Yu-Hao Tu, Rui-Feng Wang and Wen-Hao Su

Machines 2025, 13(2), 111; https://doi.org/10.3390/machines13020111 - 29 Jan 2025

Abstract

With the development of smart and precision agriculture, new challenges have emerged in terms of response speed and adaptability in agricultural equipment control. Active Disturbance Rejection Control (ADRC), an advanced control strategy known for its strong robustness and disturbance rejection capabilities, has demonstrated [...] Read more.

With the development of smart and precision agriculture, new challenges have emerged in terms of response speed and adaptability in agricultural equipment control. Active Disturbance Rejection Control (ADRC), an advanced control strategy known for its strong robustness and disturbance rejection capabilities, has demonstrated exceptional performance in various fields, such as aerospace, healthcare, and military applications. Therefore, investigating the application of ADRC in agricultural control systems is of great significance. This review focuses on the fundamental principles of ADRC and its applications in agriculture, exploring its potential use and achievements in precision agriculture management, intelligent agricultural control, and other agricultural control sectors. These include the control of agricultural machinery, field navigation and trajectory tracking, agricultural production processes, as well as fisheries and greenhouse management in various agricultural scenarios. Additionally, this paper summarizes the integration of ADRC with other control technologies (e.g., LADRC, SMC) in agricultural applications and discusses the advantages and limitations of ADRC in the aforementioned areas. Furthermore, the challenges, development trends, and future research directions of ADRC in agricultural applications are examined to provide a reference for its future development. Full article

22 pages, 5865 KiB

Open AccessArticle

Dynamic Performance Analysis and Fault Ride-Through Enhancement by a Modified Fault Current Protection Scheme of a Grid-Connected Doubly Fed Induction Generator

by Rameez Akbar Talani, Ghulam Sarwar Kaloi, Aamir Ali, Muhammad Ali Bijarani, Ghulam Abbas, Mohammed Hatatah, Paolo Mercorelli and Ezzeddine Touti

Machines 2025, 13(2), 110; https://doi.org/10.3390/machines13020110 - 29 Jan 2025

Abstract

With the increase in reliance on doubly fed induction generator-based wind energy conversion systems (DFIG-WECSs), extracting maximum power from wind energy and enhancing fault ride-through (FRT) techniques meeting the grid code requirements is the foremost concern. This paper proposes a modified control scheme [...] Read more.

With the increase in reliance on doubly fed induction generator-based wind energy conversion systems (DFIG-WECSs), extracting maximum power from wind energy and enhancing fault ride-through (FRT) techniques meeting the grid code requirements is the foremost concern. This paper proposes a modified control scheme that operates in normal running conditions and during faults as a dual mode. The proposed control scheme operates in a coordinated wind speed estimation-based maximum power point tracking (WSE-MPPT) mode during normal running conditions to extract maximum power from wind energy and enhances the crowbar rotor active impedance-based FRT mode during faults. The proposed technique controls the rotor side converter (RSC) parameters during faults by limiting the transient surge in the rotor and stator currents. In this study, the transient behavior of the proposed technique is analyzed under a three-phase symmetrical fault with a severe voltage dip, and it is observed that, when the fault is over and the RSC is activated and connected to the system, a large inrush current is produced with transient oscillations; the proposed scheme suppresses this post-fault inrush current and limits the transient oscillation. During the FRT operating mode under a symmetrical fault, the simulation results of the proposed technique are validated by the conventional crowbar strategy. In contrast, during the WSE-MPPT operating mode under normal running conditions, a smooth achievement of system parameters after starting the inrush period to a steady state at fixed wind speed is observed. Full article

(This article belongs to the Special Issue Striving toward a Sustainable and More Electrified Future: The Role of Electrical Machines and Drives)

23 pages, 5221 KiB

Open AccessArticle

Digital Twin-Based Prediction and Optimization for Dynamic Supply Chain Management

by Dong-Hun Kim, Goo-Young Kim and Sang Do Noh

Machines 2025, 13(2), 109; https://doi.org/10.3390/machines13020109 - 29 Jan 2025

Abstract

Manufacturing supply chains are becoming increasingly complex due to geopolitical issues, globalization, and market demand uncertainties. These challenges lead to logistics disruptions, inventory shortages, and interruptions in raw materials and spare parts production, resulting in delayed delivery, reduced market share, and lower customer [...] Read more.

Manufacturing supply chains are becoming increasingly complex due to geopolitical issues, globalization, and market demand uncertainties. These challenges lead to logistics disruptions, inventory shortages, and interruptions in raw materials and spare parts production, resulting in delayed delivery, reduced market share, and lower customer satisfaction. Effective supply chain management is critical for improving operational efficiency and competitiveness. This paper proposes a supply chain digital twin methodology to enhance operational efficiency through real-time monitoring, analysis, and response to disruptions. This methodology defines a supply chain digital twin system architecture and outlines the operational process of digital twin applications. It introduces two key modules: a digital twin module for prediction and monitoring and an optimization module for determining the optimal movement of products. These modules are integrated to align digital simulations with real-world supply chain operations. The proposed approach is validated through a case study of an automobile body production company’s supply chain, demonstrating its effectiveness in reducing inventory and logistics costs while providing countermeasures for abnormal situations. Full article

(This article belongs to the Section Industrial Systems)

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34 pages, 16514 KiB

Open AccessArticle

Enhanced Non-Destructive Testing of Small Wind Turbine Blades Using Infrared Thermography

by Majid Memari, Mohammad Shekaramiz, Mohammad A. S. Masoum and Abdennour C. Seibi

Machines 2025, 13(2), 108; https://doi.org/10.3390/machines13020108 - 29 Jan 2025

Abstract

This study presents a foundational step in a broader initiative aimed at leveraging thermal imaging technology to enhance wind turbine maintenance, particularly focusing on the challenges of detecting defects and object localization in small wind turbine blades. Serving as a preliminary experiment, this [...] Read more.

This study presents a foundational step in a broader initiative aimed at leveraging thermal imaging technology to enhance wind turbine maintenance, particularly focusing on the challenges of detecting defects and object localization in small wind turbine blades. Serving as a preliminary experiment, this research project tested methodologies and technologies on a smaller scale before advancing to more complex applications involving large, operational wind turbines using drone-mounted cameras. Utilizing thermal cameras suitable for both handheld and drone use, alongside advanced image processing applications, we navigated the significant challenge of acquiring high-quality thermal images to detect small defects. This required a concentrated analysis of a select subset of data and a methodological shift towards object detection and localization using the You Only Look Once (YOLO) model versions 8 and 9. This effort not only paves the way for applying these techniques to larger-scale turbines but also contributes to the ongoing development of an integrated maintenance strategy in the wind energy sector. Highlighting the critical impact of environmental conditions on thermal imaging, our research underscores the importance of continued exploration in this field, especially in enhancing object localization techniques for the future drone-based maintenance of operational wind turbine blades (WTBs). Full article

(This article belongs to the Special Issue Signal Processing and Artificial Intelligence Technology for High-End Equipment Fault Diagnosis)

29 pages, 1426 KiB

Open AccessArticle

The Space Phasors Theory and the Conditions for the Correct Decoupling of Multiphase Machines

by Luis Serrano-Iribarnegaray and Jorge Bonet-Jara

Machines 2025, 13(2), 107; https://doi.org/10.3390/machines13020107 - 29 Jan 2025

Abstract

This paper first analyzes the general statements accepted in the technical literature concerning the complete dynamic decoupling of constant air-gap multiphase machines with space harmonics (usually resorting to the instantaneous symmetrical components, ISCs) and shows that they are not correct, since they only [...] Read more.

This paper first analyzes the general statements accepted in the technical literature concerning the complete dynamic decoupling of constant air-gap multiphase machines with space harmonics (usually resorting to the instantaneous symmetrical components, ISCs) and shows that they are not correct, since they only hold (and only with good approximation) for the particular case of converter-controlled machines. It then deduces in a rigorous theoretical way the correct conditions in all cases for both a precise and an approximate decoupling of multiphase machines and thereupon verifies them through numerous simulations. To do that, the Space Phasors Theory (SPhTh) is applied, whose true core, often unknown or misunderstood, is clearly explained. Preceding this point, the concept of the dynamic phasor of g sequence, which is a fundamental tool in the SPhTh, is introduced, and a necessary historical and critical review of the ISCs is undertaken. Full article

(This article belongs to the Section Electrical Machines and Drives)

25 pages, 4548 KiB

Open AccessArticle

The Secondary Lifting Performance of Crawler Crane Under Delay Coefficient Control Strategy

by Jin Zhang, Ranheng Du, Kuo Zhang, Yin Zhang, Ying Li and Xing Chen

Machines 2025, 13(2), 106; https://doi.org/10.3390/machines13020106 - 29 Jan 2025

Abstract

Crawler cranes are mobile lifting equipment used in the process of hoisting goods. After the initial lifting, the crane may need a secondary lift due to adjustments in the position or height of the load. Addressing the common issue of load slipping during [...] Read more.

Crawler cranes are mobile lifting equipment used in the process of hoisting goods. After the initial lifting, the crane may need a secondary lift due to adjustments in the position or height of the load. Addressing the common issue of load slipping during the secondary lift caused by hydraulic motor reversal, this study proposes a control strategy applicable to crawler crane secondary lifting. Initially establishing the dynamic characteristics of the secondary lift system, incorporating a delay coefficient, and matching motor pressure build-up with memory pressure, the strategy considers a variable pump input current control to identify the relationship between motor pressure build-up and brake release. Analyzing the dynamic characteristics of secondary lifting under different conditions, this study resolves the issue of hydraulic motor reversal during the second lift caused by heavy loads. The results of this study on crawler crane secondary lifting indicate that, when using a delay coefficient of 0.70 and releasing the brake, no slip phenomenon occurred during the secondary lift process under different load conditions, categorized as 200 tons, 600 tons, and 1000 tons. This ensures the stability and transition quality of the secondary lift, providing theoretical guidance for the control of the crawler crane secondary lifting. Full article

(This article belongs to the Section Machine Design and Theory)

16 pages, 1111 KiB

Open AccessArticle

Wear and Plasticity in Railway Turnout Crossings: A Fast Semi-Physical Model to Replace FE Simulations

by Hamed Davoodi Jooneghani, Kamil Sazgetdinov, Alexander Meierhofer, Stephan Scheriau, Uwe Ossberger, Gabor Müller and Klaus Six

Machines 2025, 13(2), 105; https://doi.org/10.3390/machines13020105 - 28 Jan 2025

Abstract

Severe changes in the profiles of the crossing nose are caused by large dynamic contact forces. To predict these forces as well as the profile evolution, the Whole System Model (WSM) was developed. However, it uses computationally expensive FE simulations. As a replacement, [...] Read more.

Severe changes in the profiles of the crossing nose are caused by large dynamic contact forces. To predict these forces as well as the profile evolution, the Whole System Model (WSM) was developed. However, it uses computationally expensive FE simulations. As a replacement, the semi-physical plasticity and wear model (SPPW) has been developed, thus majorly enhancing the overall performance of the WSM. The SPPW considers the influence of wear, plasticity, and wheel-profile-related effects. Its results have shown an overall good correlation with FE results, laboratory data for different materials, and field data from a real crossing. Due to the semi-physical nature of the model, the required computational time for the predictions was significantly reduced compared to FE simulations: minutes instead of weeks. The SPPW will be useful for time-efficient rail damage prediction, like wear and plastic deformation, and, as part of the WSM, contribute to a fast holistic track damage prognosis. Full article

(This article belongs to the Special Issue Wheel–Rail Contact: Mechanics, Wear and Analysis)

16 pages, 5811 KiB

Open AccessArticle

Enhancing Spraying Performance with Active Stability Control in Multi-Link Mechanisms

by Naiyu Shi, He Li, Yongkang Yang, Hongliang Hua, Junhong Ye, Zheng Chen and Ting Xu

Machines 2025, 13(2), 104; https://doi.org/10.3390/machines13020104 - 28 Jan 2025

Abstract

This study proposes an active stability control method for the multi-link mechanism of spraying equipment to enhance its spraying performance. Traditional spraying operations typically focus on protecting only the tops of crops, whereas the multi-link mechanism can adjust the angle and position of [...] Read more.

This study proposes an active stability control method for the multi-link mechanism of spraying equipment to enhance its spraying performance. Traditional spraying operations typically focus on protecting only the tops of crops, whereas the multi-link mechanism can adjust the angle and position of the nozzles in coordination, achieving comprehensive protection for the crops. However, the characteristic of uneven output speed in the multi-link mechanism results in variations in the spraying amount at different positions. To address this issue, this study developed a method for actively adjusting the stability of the output end speed. First, a differential equation was established to relate the input speed to the output speed using vector methods, implicit function transformation to explicit functions, and regression analysis. The feasibility of this method was verified through simulations using MATLAB Simulink R2018a and Adams 2018. Prototype test results indicate that this speed adjustment method improved the stability of the output angular velocity, reducing the coverage rate variation between the upward, sideways, and downward of the leaves by 12.53% during the spraying process. Therefore, the method proposed in this study can enhance the uniformity of spraying, further improving the utilization of pesticides, which is beneficial for the green ecological sustainable development in the agricultural field. Additionally, this control method is also applicable to other types of link mechanisms, providing a reference for improving the output stability of link mechanisms. Full article

(This article belongs to the Section Machine Design and Theory)

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13 pages, 2703 KiB

Open AccessArticle

Research on Tightening Technique of Turbopump Shaft System Based on Elongation Method

by Zelin Wang, Liang Zhou, Guangyuan Jin, Ao Han and Weide Gu

Machines 2025, 13(2), 103; https://doi.org/10.3390/machines13020103 - 27 Jan 2025

Abstract

As the key role of turbopumps in spacecraft engines becomes increasingly prominent, accurate control of their shaft system tightening force is significant to ensure the stable operation of the engines. Although the traditional torque method has been widely used in the tightening of [...] Read more.

As the key role of turbopumps in spacecraft engines becomes increasingly prominent, accurate control of their shaft system tightening force is significant to ensure the stable operation of the engines. Although the traditional torque method has been widely used in the tightening of threaded connections, the tightening force is easily affected by the quality of threads and lubrication conditions, and the accuracy and consistency are poor. This paper investigates the elongation method based on the turbopump shaft system tightening force control method. It is applied to the turbopump rotor assembly scenario for the first time. The performance of the torque and elongation methods under different thread qualities and lubrication conditions is compared through experiments. The experimental results show that the elongation method has significant advantages in improving the consistency and accuracy of the tightening force, especially under poor thread fit or different lubrication conditions. Full article

(This article belongs to the Section Turbomachinery)

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22 pages, 2297 KiB

Open AccessArticle

Six Sigma-Based Mathematical Optimization Framework for Flux-Switching Machines: A Roadmap for Quality, Performance, and Manufacturing Tolerances

by Chiweta E. Abunike, Ogbonnaya I. Okoro and Sumeet S. Aphale

Machines 2025, 13(2), 102; https://doi.org/10.3390/machines13020102 - 27 Jan 2025

Abstract

Flux-switching wound field machines (FSWFMs) offer high torque density and independence from rare-earth materials, making them promising candidates for sustainable electric vehicles and industrial applications. However, their adoption is limited by challenges such as high torque ripple, efficiency variations, and sensitivity to manufacturing [...] Read more.

Flux-switching wound field machines (FSWFMs) offer high torque density and independence from rare-earth materials, making them promising candidates for sustainable electric vehicles and industrial applications. However, their adoption is limited by challenges such as high torque ripple, efficiency variations, and sensitivity to manufacturing tolerances. This study presents a Design for Six Sigma (DFSS) optimization framework that integrates sensitivity analysis, response surface modeling (RSM), and multi-objective genetic algorithms to address these challenges. The optimized solution reduces torque ripple by 7.69%, improves torque output, and enhances energy efficiency. By incorporating Six Sigma principles, the framework ensures robust performance under manufacturing variations, bridging the gap between theoretical optimization and practical implementation. This scalable and efficient methodology establishes FSWFMs as viable solutions for industrial applications, revolutionizing electric machine design. Full article

(This article belongs to the Section Electrical Machines and Drives)

29 pages, 4785 KiB

Open AccessReview

A Review of the Applications and Challenges of Dielectric Elastomer Actuators in Soft Robotics

by Qinghai Zhang, Wei Yu, Jianghua Zhao, Chuizhou Meng and Shijie Guo

Machines 2025, 13(2), 101; https://doi.org/10.3390/machines13020101 - 27 Jan 2025

Abstract

As an electrically driven artificial muscle, dielectric elastomer actuators (DEAs) are notable for their large deformation, fast response speed, and high energy density, showing significant potential in soft robots. The paper discusses the working principles of DEAs, focusing on their reversible deformation under [...] Read more.

As an electrically driven artificial muscle, dielectric elastomer actuators (DEAs) are notable for their large deformation, fast response speed, and high energy density, showing significant potential in soft robots. The paper discusses the working principles of DEAs, focusing on their reversible deformation under electric fields and performance optimization through material and structural innovations. Key applications include soft grippers, locomotion robots (e.g., multilegged, crawling, swimming, and jumping/flying), humanoid robots, and wearable devices. The challenges associated with DEAs are also examined, including the actuation properties of DE material, material fatigue, viscoelastic effects, and environmental adaptability. Finally, modeling and control strategies to enhance DEA performance are introduced, with a perspective on future technological advancements in the field. Full article

(This article belongs to the Special Issue Dielectric Elastomer Actuators: Theory, Modeling and Application)

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32 pages, 17933 KiB

Open AccessArticle

Experimental-Based Simulation of EV Drive Mechanism

by Lakith Jinadasa, Perla Yadav, Alex Wray and Kambiz Ebrahimi

Machines 2025, 13(2), 100; https://doi.org/10.3390/machines13020100 - 27 Jan 2025

Abstract

A robust experimental-based vehicle drive system model and parameters tuned to match the real-world performance of the electro-mechanical systems is presented. The model is based on battery electric vehicle systems, focusing on the individual components of the drive system. The model includes motors, [...] Read more.

A robust experimental-based vehicle drive system model and parameters tuned to match the real-world performance of the electro-mechanical systems is presented. The model is based on battery electric vehicle systems, focusing on the individual components of the drive system. The model includes motors, a battery pack, a driveline, and a DC-DC converter. Based on the collected empirical data using an on-board data acquisition system, and fine-tuning the critical vehicle parameters to align the simulation with the empirical data, stationary and drive cycle tests were designed and performed to replicate standard day-to-day driving conditions. Performance metrics such as the power consumption, the state of charge and the range were employed for the model validation. The validated model was then used for the performance study at different operating temperatures. The results of the study demonstrate that the model successfully mirrored the performance of the powertrain under various conditions and lined up with existing research work, providing a valuable tool for further research and development in battery electric vehicle technology. Full article

(This article belongs to the Section Vehicle Engineering)

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15 pages, 2342 KiB

Open AccessArticle

Numerical Modeling and Optimization of Nomex Honeycomb Core Milling: Influence of Longitudinal and Longitudinal–Torsional Ultrasonic Vibrations

by Tarik Zarrouk, Mohammed Nouari and Hicham Bouali

Machines 2025, 13(2), 99; https://doi.org/10.3390/machines13020099 - 27 Jan 2025

Abstract

Nomex honeycomb structures (NHCs) have currently experienced significant development, mainly in the aeronautics, aerospace, marine, and automotive sectors. This expansion raises noteworthy challenges related to the improvement of machining excellence, necessitating the use of particular cutting tools and adapted techniques. With this in [...] Read more.

Nomex honeycomb structures (NHCs) have currently experienced significant development, mainly in the aeronautics, aerospace, marine, and automotive sectors. This expansion raises noteworthy challenges related to the improvement of machining excellence, necessitating the use of particular cutting tools and adapted techniques. With this in mind, experimental studies were conducted to analyze the specificities of Nomex honeycomb cores milling by integrating longitudinal ultrasonic vibrations along the cutting tool rotation axis (UCK). However, the high tool speed and the unreachability of the tool-workpiece interface complicate the direct observation of the cutting process. To overcome these challenges, a 3D numerical model was developed to simulate the milling of composite honeycomb structures by integrating longitudinal and longitudinal–torsional ultrasonic vibrations. This model was developed by Abaqus/Explicit software, version 2017. The obtained results indicate that the integration of longitudinal–torsional vibrations allows a reduction in cutting forces by up to 28%, a reduction in the accumulation of material in front of the cutting tool, with a maximum reduction of 30%, and an improvement in the quality of the machined surface. Full article

(This article belongs to the Special Issue Machine Tools for Precision Machining: Design, Control and Prospects)

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16 pages, 8593 KiB

Open AccessArticle

Smart Machine Vision System to Improve Decision-Making on the Assembly Line

by Carlos Americo de Souza Silva and Edson Pacheco Paladini

Machines 2025, 13(2), 98; https://doi.org/10.3390/machines13020098 - 27 Jan 2025

Abstract

Technological advances in the production of printed circuit boards (PCBs) are increasing the number of components inserted on the surface. This has led the electronics industry to seek improvements in their inspection processes, often making it necessary to increase the level of automation [...] Read more.

Technological advances in the production of printed circuit boards (PCBs) are increasing the number of components inserted on the surface. This has led the electronics industry to seek improvements in their inspection processes, often making it necessary to increase the level of automation on the production line. The use of machine vision for quality inspection within manufacturing processes has increasingly supported decision making in the approval or rejection of products outside of the established quality standards. This study proposes a hybrid smart-vision inspection system with a machine vision concept and vision sensor equipment to verify 24 components and eight screw threads. The goal of this study is to increase automated inspection reliability and reduce non-conformity rates in the manufacturing process on the assembly line of automotive products using machine vision. The system uses a camera to collect real-time images of the assembly fixtures, which are connected to a CMOS color vision sensor. The method is highly accurate in complex industry environments and exhibits specific feasibility and effectiveness. The results indicate high performance in the failure mode defined during this study, obtaining the best inspection performance through a strategy using Vision Builder for automated inspection. This approach reduced the action priority by improving the failure mode and effect analysis (FMEA) method. Full article

(This article belongs to the Topic Smart Production in Terms of Industry 4.0 and 5.0)

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