Machines

22 pages, 5753 KiB

Open AccessArticle

Analysis of Energy Efficiency in Spur Gear Transmissions: Cycloidal Versus Involute Profiles

by Joaquim Maria Veciana, Pau Salvadó, Pau Català and Lluïsa Jordi

Machines 2024, 12(12), 943; https://doi.org/10.3390/machines12120943 (registering DOI) - 21 Dec 2024

The involute profile is used almost exclusively in the manufacturing of spur gears. Nevertheless, in machinery design, the evaluation of environmental factors, such as energy efficiency, has become increasingly important when choosing between feasible solutions. As a result, the study of alternative profiles [...] Read more.

The involute profile is used almost exclusively in the manufacturing of spur gears. Nevertheless, in machinery design, the evaluation of environmental factors, such as energy efficiency, has become increasingly important when choosing between feasible solutions. As a result, the study of alternative profiles is gaining interest. The key novelty of this study is the comparative analysis of involute and cycloidal gear profiles with respect to frictional power losses in the tooth contact, as well as their impact on energy efficiency in spur gear transmissions. The coefficient of friction is approximated using two widely applied analytical lubrication models: the elastohydrodynamic and mixed elastohydrodynamic, both of which provide enough accurate values with a reasonable amount of computation burden in comparison with numerical methods. An additional contribution of this study is a sensitivity assessment of the energy efficiency of the cycloidal profile with regard to the auxiliary centrode diameters. This allows for an understanding of the geometrical constraints of this profile, specifically the maximum pressure angle—which is related to the radial loads applied to the shaft—and the tooth height—which is related to the bending moment at the tooth root—and hence, setting the appropriate ones to be equivalent to the involute profile. For the comparative analysis, equivalent profiles are selected based on similar tooth bending moments and radial loads supported by the shaft. After determining the centrode diameters of the cycloidal profile, the efficiency of both gear profiles and their sensitivity to gear size and gear ratio are compared. This study concludes that, for both profiles and friction analytical models, efficiency improves with increasing gear sizes and gear ratios, eventually converging to a constant value. Furthermore, both cycloidal and involute profiles exhibit comparable performance in terms of energy efficiency across both lubrication analytical models. Full article

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

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16 pages, 2388 KiB

Open AccessArticle

Modeling of Chatter Stability for the Robot Milling of Natural Marble

by Jixiang Huang, Hui Huang, Shengui Huang and Fangchen Yin

Machines 2024, 12(12), 942; https://doi.org/10.3390/machines12120942 (registering DOI) - 21 Dec 2024

Abstract

Industrial robots are widely used in the field of processing because of their many advantages, such as their high flexibility and wide processing range, but the chatter phenomenon limits their application. In this study, a chatter model for the robot milling of natural [...] Read more.

Industrial robots are widely used in the field of processing because of their many advantages, such as their high flexibility and wide processing range, but the chatter phenomenon limits their application. In this study, a chatter model for the robot milling of natural marble is established that analyzes the effect of the milling parameters and position. The chatter stability model is first established based on the zeroth-order approximation method, in which the robot milling system is simplified into a vibration system with two degrees of freedom. The milling force coefficients are determined by robot milling experiments, and the modal parameters of the robot milling system are identified based on the single-point excitation and pickup methods, which are essential for the establishment of the chatter stability model. Second, robot milling experiments are conducted to verify the established model, proving its high prediction accuracy. Finally, the effect of the milling parameters and position on the chatter stability of the robot milling system is discussed. These conclusions can be references for the robot milling of natural marble. Full article

(This article belongs to the Section Material Processing Technology)

20 pages, 1079 KiB

Open AccessArticle

Machinery Regulation and Remanufacturing: A Link Between Machinery Safety and Sustainability

by Stefano Beneduce, Leonardo Vita, Luciano Cantone and Francesco Caputo

Machines 2024, 12(12), 941; https://doi.org/10.3390/machines12120941 (registering DOI) - 21 Dec 2024

Abstract

On 14 June 2023, the European Parliament adopted Regulation (EU) 2023/1230 on machinery, which entered into force on 19 July 2023 (with some exceptions as per art. 54, according to a corrigendum issued to address a clerical error as regards the application dates [...] Read more.

On 14 June 2023, the European Parliament adopted Regulation (EU) 2023/1230 on machinery, which entered into force on 19 July 2023 (with some exceptions as per art. 54, according to a corrigendum issued to address a clerical error as regards the application dates in the original version) and shall apply from 20 January 2027, replacing the Machinery Directive 2006/42/EC. The main innovations/differences introduced by the Machinery Regulation (MR) compared to the Machinery Directive (MD) are critically analysed here, with a focus on sustainability issues. Some of these issues are covered by several international standards (such as BS 8887, ISO 10987 or DIN 91472), which also define the criteria and requirements for the remanufacturing process, although some technical gaps remain. Using the example of agricultural machinery, this paper proposes a methodology for determining the areas of acceptability for remanufactured products: these are expressed in terms of structural performance (e.g., the number of cycles ahead to failure expressed as the mutual of damage

1 - D = 0.625

) and the functional and safety requirements of the original machine. In this way, the issue of “substantial modification of machinery” is explored in terms of the safety obligations that the remanufactured machinery must fulfil. The paper is therefore a contribution to circular design by providing general criteria for the extension of the service life of machinery while at the same time considering safety issues. Full article

(This article belongs to the Section Advanced Manufacturing)

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16 pages, 7094 KiB

Open AccessArticle

Research on the Strain and Stress of Powered Roof Support Construction to Limit Damage

by Dawid Szurgacz

Machines 2024, 12(12), 940; https://doi.org/10.3390/machines12120940 (registering DOI) - 21 Dec 2024

Abstract

A powered roof support in a mining complex comprises a set of sections positioned side by side. Thus, it creates space for the mining longwall shearer and the excavated material haulage conveyor. The main role of the powered roof support is to secure [...] Read more.

A powered roof support in a mining complex comprises a set of sections positioned side by side. Thus, it creates space for the mining longwall shearer and the excavated material haulage conveyor. The main role of the powered roof support is to secure the machinery and equipment, as well as the working crew. This roof support also takes over the load from the rock mass during operation. The loads and phenomena that cause damage to the powered roof support construction in real conditions became the basis for conducting a series of studies and analyses of the stresses and strains that occur. This study aimed to obtain the results of research and analysis on the damage to the floor base, which is the most important part of the entire powered roof support construction. The actual pressure measurements carried out in the space under the piston leg of the powered roof support under real conditions indicated an excessive load on the powered roof support construction. This load was mainly due to the ceiling conditions, while the floor conditions for providing the construction were difficult to determine due to the too-soft floor substrate. The Finite Element Method (FEM) was used to solve the problem. The construction of the two powered roof support bases was subjected to numerical analysis in order to propose structural changes. The obtained numerical test results indicated a solution to the problem of damage and significant structural changes. Full article

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

19 pages, 5436 KiB

Open AccessArticle

A Hybrid DWA-MPC Framework for Coordinated Path Planning and Collision Avoidance in Articulated Steering Vehicles

by Xuanwei Chen, Changlin Yang, Huosheng Hu, Yunlong Gao, Qingyuan Zhu and Guifang Shao

Machines 2024, 12(12), 939; https://doi.org/10.3390/machines12120939 (registering DOI) - 20 Dec 2024

Abstract

This paper presents an autonomous collision avoidance method that integrates path planning and control for articulated steering vehicles (ASVs) operating in underground tunnel environments. The confined nature of tunnel spaces, combined with the complex structure of ASVs, increases the risk of collisions due [...] Read more.

This paper presents an autonomous collision avoidance method that integrates path planning and control for articulated steering vehicles (ASVs) operating in underground tunnel environments. The confined nature of tunnel spaces, combined with the complex structure of ASVs, increases the risk of collisions due to path-tracking inaccuracies. To address these challenges, we propose a DWA-based obstacle avoidance algorithm specifically tailored for ASVs. The method incorporates a confidence ellipse, derived from the time-varying distribution of tracking errors, into the DWA evaluation function to effectively assess collision risk. Furthermore, the execution accuracy of DWA is improved by integrating a kinematic-based Model Predictive Control. The proposed approach is validated through simulations and field tests, with results demonstrating significant enhancements in collision avoidance and path-tracking accuracy in confined spaces compared to conventional DWA methods. Full article

(This article belongs to the Special Issue Dynamics and Path Planning for Autonomous Vehicles)

20 pages, 6926 KiB

Open AccessArticle

Modeling and Characteristic Test for a Crank-Connecting Rod Mem-Inerter Device

by Xiao-Liang Zhang, Ya-Lin Chen, Jia-Mei Nie and Wei-An Zhu

Machines 2024, 12(12), 938; https://doi.org/10.3390/machines12120938 (registering DOI) - 20 Dec 2024

Abstract

This paper presents a mechanical crank-connecting rod mem-inerter device, with its output and memory characteristics being investigated and validated. Previous research suggests that a hydraulic mem-inerter generates a sizeable damping force, practically transforming it into a mem-dashpot. This greatly influences a system’s vibration [...] Read more.

This paper presents a mechanical crank-connecting rod mem-inerter device, with its output and memory characteristics being investigated and validated. Previous research suggests that a hydraulic mem-inerter generates a sizeable damping force, practically transforming it into a mem-dashpot. This greatly influences a system’s vibration characteristics when using a hydraulic mem-inerter. In contrast, the proposed crank-connecting rod inerter exhibits negligible damping force, addressing the issue of excessive damping in hydraulic inerters and potentially enhancing the actual isolation effect. We successfully developed a prototype of the trial production device, and a bench characteristic test was conducted. Our quasi-static test results indicate that frictional resistance during device operation can be negligible. Our dynamic characteristic test results reveal that the characteristic curves of the device on the momentum–velocity plane can be displayed as a pinched hysteresis loop. Our results are in agreement with the simulation outcomes, which proves that the crank-connecting rod inerter is a physical realization of a mem-inerter device. Full article

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

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21 pages, 3226 KiB

Open AccessArticle

Study of Cutting Forces in Drilling of Aluminum Alloy 2024-T351

by Răzvan Sebastian Crăciun, Virgil Gabriel Teodor, Nicușor Baroiu, Viorel Păunoiu and Georgiana-Alexandra Moroșanu

Machines 2024, 12(12), 937; https://doi.org/10.3390/machines12120937 (registering DOI) - 20 Dec 2024

Abstract

Duralumin 2024-T351 is an alloy characterized by a good mechanical strength, relatively high hardness and corrosion resistance frequently used in the aeronautical, automotive, defense etc. industries. In this paper, the variation of axial forces and torques when drilling aluminum alloy 2024-T351 was investigated, [...] Read more.

Duralumin 2024-T351 is an alloy characterized by a good mechanical strength, relatively high hardness and corrosion resistance frequently used in the aeronautical, automotive, defense etc. industries. In this paper, the variation of axial forces and torques when drilling aluminum alloy 2024-T351 was investigated, analyzing the measured values for different cutting regimes. Experimental data on the forces and moments generated during the drilling process were collected using specialized equipment, and these data were preprocessed and analyzed using MatLab R218a. The experimental plan included 27 combinations of the parameters of the cutting regime (cutting depth, cutting speed, and feed), for which energetic cutting parameters were measured, the axial force and the torsion moment, respectively Based on these data, a neural network was trained, using the Bayesian regularization algorithm, in order to predict the optimal values of the cutting energy parameters. The neural model proved to be efficient, providing predictions with a relative error below 10%, indicating a good agreement between measured and simulated values. In conclusion, neural networks offer an accurate alternative to classical analytical models, being more suitable for materials with complex behavior, such as aluminum alloys. Full article

(This article belongs to the Section Advanced Manufacturing)

15 pages, 8534 KiB

Open AccessArticle

Development of Digital Flow Valve Applied to Aero-Engine Fuel Control and Research on Performance of Its Flow Characteristics

by Yuesong Li

Machines 2024, 12(12), 936; https://doi.org/10.3390/machines12120936 (registering DOI) - 20 Dec 2024

Abstract

Digital valves have strong anti-pollution ability and good linearity, so they are more suitable for aero-engine fuel control. However, for high-precision flow control, incremental digital valves require a high-precision, high-dynamic servomotor drive; binary-coded digital valves require many on/off valves; and high-speed switching digital [...] Read more.

Digital valves have strong anti-pollution ability and good linearity, so they are more suitable for aero-engine fuel control. However, for high-precision flow control, incremental digital valves require a high-precision, high-dynamic servomotor drive; binary-coded digital valves require many on/off valves; and high-speed switching digital valves can cause flow shock and pulsation. In this study, an aero-engine fuel control decimal-coded digital flow valve was developed, which not only has the advantages of digital valves but also avoids the above problems. Firstly, the structure and operation principle of the decimal-coded digital flow valve is introduced; then, its model is established based on Simulink/Simcape, and its flow characteristics are simulated and analyzed. Then, experiments on the flow characteristics are presented. The simulation and experiment show that under a supply pressure of 1 MPa, 2 MPa, and 3 MPa, the maximum flow of the decimal-coded digital valve is 11.4457 L/min, 16.3719 L/min, and 19.3733 L/min, and the control accuracy is 0.0775 L/min, 0.1086 L/min, and 0.1294 L/min, respectively. In addition, it has very good linearity, and the settling time is less than 0.09s. Full article

(This article belongs to the Section Automation and Control Systems)

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15 pages, 12940 KiB

Open AccessArticle

Design and Comparison of Two Maize Seeders Coupled with an Agricultural Robot

by Jesús A. López-Gómez, Joshua E. Patiño-Espejel, Noé Velázquez-López, David I. Sánchez-Chávez and Jelle Van Loon

Machines 2024, 12(12), 935; https://doi.org/10.3390/machines12120935 - 20 Dec 2024

Abstract

In recent years, the development of robotic vehicles in agriculture has made it possible to reduce human intervention and fatigue in carrying out arduous or repetitive tasks, as well as helping to promote sustainable agriculture to address climate change. However, the great diversity [...] Read more.

In recent years, the development of robotic vehicles in agriculture has made it possible to reduce human intervention and fatigue in carrying out arduous or repetitive tasks, as well as helping to promote sustainable agriculture to address climate change. However, the great diversity of agricultural tasks and the varied production systems and crops demand a wide range of solutions that can be adapted to robotic vehicles as a power source. These alternatives must be affordable and user-friendly for some users, although more sophisticated solutions must also be developed for others, depending on their specific needs. For this, the present work focuses on the development of two maize seeders with different metering systems coupled to an agricultural robot. The first seeder has a conventional mechanically driven seed metering system with a drive wheel and chain gear, while the second one has an electronically driven metering system based on a DC motor and a digital encoder controlled by a microcontroller. Both seeders were coupled to a remote-controlled robotic vehicle and evaluated on real farmland. Seed distribution in the seed rows was contrasting; the results indicated that the mechanical system performed better in the field than the electronic system. For both seeders, the working capacity was approximately 0.135 ha/h at an average speed of 2.0 km/h. The proposed robot–seeder assembly could help farmers automate and reduce the workload associated with planting, as well as attract young people to the field. Full article

(This article belongs to the Special Issue Design and Control of Agricultural Robots)

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18 pages, 6079 KiB

Open AccessArticle

Trajectory Planning for Reciprocating Motion in Integrated Servo Motor Linear Stages

by Max Schnegas and Musa K. Jouaneh

Machines 2024, 12(12), 934; https://doi.org/10.3390/machines12120934 - 20 Dec 2024

Abstract

Many applications in manufacturing, physical therapy, and machining require linear motion stages to move back and forth at specified rates without exceeding the capabilities of the stages. Growing interest has also been in using integrated servo motors for these applications, which would benefit [...] Read more.

Many applications in manufacturing, physical therapy, and machining require linear motion stages to move back and forth at specified rates without exceeding the capabilities of the stages. Growing interest has also been in using integrated servo motors for these applications, which would benefit from the integrated nature of the motor, feedback device, and drive electronics in a single package. This paper introduces a methodology for trajectory planning for the reciprocating motion for a linear motion device. The methodology can be implemented on any device, and a simplified version can be applied to the control software for integrated servo motors. The approach develops motion trajectories, such as triangular or trapezoidal, using a dynamic model of the device and the motor’s torque–speed profile characteristics. The simplified version of the methodology was implemented using an integrated servo motor driving a ball screw stage. Tests were conducted at various motion rates and loads. The experimental results show high accuracy between the predicted and measured motion rates, particularly for rates below three cycles per second. These results suggest that the developed methodology can be a valuable tool for predicting the performance of systems that use integrated servo motors for reciprocating motion applications. Full article

(This article belongs to the Special Issue Advances in Applied Mechatronics, Volume II)

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18 pages, 13730 KiB

Open AccessArticle

Additive Manufacturing of Biomimetic Near-Zero CTE Optical Structures

by Shuang Bai, David Cheng and Jian Liu

Machines 2024, 12(12), 933; https://doi.org/10.3390/machines12120933 - 20 Dec 2024

Abstract

Super invar, with its near-zero coefficient of thermal expansion (CTE), has a great potential to be used in the design and fabrication of high-precision optical structures, such as optical mirror substrates. In order to reduce the weight and maintain the strength of the [...] Read more.

Super invar, with its near-zero coefficient of thermal expansion (CTE), has a great potential to be used in the design and fabrication of high-precision optical structures, such as optical mirror substrates. In order to reduce the weight and maintain the strength of the mirror substrate, several biomimetic lattice designs were investigated in this paper. The static modeling provides a systematic study on different types of biomimetic mirror substrates. The impact of structure parameters, such as the wall thickness, lattice unit length, height of the lattice structure, and the thickness of the side plate, are also studied. It turns out that the three-layer lattice-structured composite mirror substrate has the best performance. With AM techniques, three-layer gyroid optical structures, which are not possible to fabricate with conventional manufacturing technology, were designed and printed with our in-house-built AM machine. The stiffness test of the gyroid specimens was in good agreement with the modeling results. The gyroid structure shows about a 20% improvement over the honeycomb structure. The gyroid design reduces the equivalent density to 1.8 g/cm³ and has an order-of-magnitude improvement on the thermal deformation, while maintaining a comparable strength with that of beryllium. Full article

(This article belongs to the Special Issue Recent Advances in 3D Printing in Industry 4.0)

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17 pages, 10100 KiB

Open AccessArticle

Vibration Principles Research of Novel Power Electronic Module as Dynamic Vibration Absorber for Chassis-By-Wire

by Xiaoyu Ding, Wei Wang and Xinbo Chen

Machines 2024, 12(12), 932; https://doi.org/10.3390/machines12120932 - 19 Dec 2024

Abstract

This paper presents a novel power electronic module (PEM) for chassis-by-wire in passenger cars. The PEM is supposed to be installed in a close-to-wheel position, which provides electrical interfaces with a power harness and signal harness. When the vehicle is driving, the PEM [...] Read more.

This paper presents a novel power electronic module (PEM) for chassis-by-wire in passenger cars. The PEM is supposed to be installed in a close-to-wheel position, which provides electrical interfaces with a power harness and signal harness. When the vehicle is driving, the PEM works as a dynamic vibration absorber (DVA) to diminish the negative effects of un-sprung mass. Based on the vibration system model, the mechanical principles are analyzed and the design parameters are mathematically optimized. For a comparison of different configuration schemes with an in-wheel motor (IWM), we take the condition of a vehicle driving at a speed of 15 m/s on a C-class road to examine indicators of vehicle body acceleration, wheel dynamic load, and suspension dynamic deflection. The calculation results prove that the system has advantages in ride comfort and wheel grounding characteristics. For the detailed design of the machine, we build a digital virtual prototype for simulation. Compared to the initial state, the optimized DVA configuration has obvious suppression in component vibration, including the vehicle body, the IWM, and the PEM. The frequency sweep analysis proves a robust result, which ensures that the frequency and amplitude are both within the vibration tolerance range of PEM operations. Full article

(This article belongs to the Special Issue Innovations in Power Electronics and Control for Sustainable Energy Systems and Electrified Transportation)

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20 pages, 5927 KiB

Open AccessArticle

Design of Active Suspension Controllers for 8 × 8 Armored Combat Vehicles

by Yonghwan Jeong and Seongjin Yim

Machines 2024, 12(12), 931; https://doi.org/10.3390/machines12120931 - 18 Dec 2024

Abstract

This paper presents a method to design an active suspension controller for 8 × 8 armored combat vehicles, which is called corner damping control (CDC). It is assumed that the target vehicle with 8 × 8 drive mechanisms and 8 suspensions has active [...] Read more.

This paper presents a method to design an active suspension controller for 8 × 8 armored combat vehicles, which is called corner damping control (CDC). It is assumed that the target vehicle with 8 × 8 drive mechanisms and 8 suspensions has active actuators on each suspension for vertical, roll and pitch motion control on a sprung mass. A state-space model with 22 state variables is derived from the target vehicle. With the state-space model, a linear quadratic (LQ) cost function is defined. The control objective is to reduce the vertical acceleration, pitch and roll angles of a sprung mass for ride comfort, durability and turret stabilization. To avoid full-state feedback of LQR, a static output feedback control (SOF) is selected as a control structure for CDC. The vertical velocity, roll and pitch rates of a sprung mass, and vertical velocities at each corner, are selected as a sensor output. With those sensor outputs and LQ cost function, four LQ SOF controllers are designed. To validate the effectiveness of the LQ SOF controllers, simulation is carried out on a vehicle simulation package. From the simulation results, it is shown that the proposed CDC with LQ SOF controllers with a much smaller number of sensor outputs and controller gains can reduce the vertical acceleration, pitch and roll angles of a sprung mass and, as a result, improve ride comfort, durability and turret stabilization. Full article

(This article belongs to the Special Issue Advances in Vehicle Suspension System Optimization and Control)

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10 pages, 2663 KiB

Open AccessArticle

AI-Assisted 3D Modeling Strategy for Microstructure-Based Functional Surfaces Using ChatGPT and Random Forest

by Younghun Noh, Sucheong Park and Sungho Lee

Machines 2024, 12(12), 930; https://doi.org/10.3390/machines12120930 - 18 Dec 2024

Abstract

With the development of computer programming, product design is being carried out through computer programming such as 3D CAD/CAM when developing products, and the cost of developing new products can be greatly reduced by using 3D modeling tools in which various engineering theories [...] Read more.

With the development of computer programming, product design is being carried out through computer programming such as 3D CAD/CAM when developing products, and the cost of developing new products can be greatly reduced by using 3D modeling tools in which various engineering theories are programmed. With the recent rapid development of artificial intelligence (AI), various AI applications have been actively proposed in various fields. In this study, we report a ChatGPT-based 3D modeling program (CMP) which can easily design microstructures, and the theory of wettability that was programmed into the CMP. Since the theory related to wettability is programmed into the CMP, once the user enters basic information about the desired functional surface, such as superhydrophobic surfaces, at the CMP prompt, 3D structures with the performance of superhydrophobicity are immediately provided. Through microstructure fabrication techniques, the microstructure designed by the CMP was actually fabricated, wettability experiments were conducted, and it was confirmed that a superhydrophobic surface was successfully designed. As such, the AI-based CMP can easily design microstructure-based functional surfaces, and we expect this method not only to decrease the fabrication costs of designing micro/nano structures but also to be useful in various fields. Full article

(This article belongs to the Section Advanced Manufacturing)

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14 pages, 7105 KiB

Open AccessArticle

Research on a Novel Flux-Switching Permanent Magnet Motor with Adjustable Torque Ripple Using an Auxiliary Rotor

by Chen Liu, Dewei Xu, Wenwu Wu and Bo Yang

Machines 2024, 12(12), 929; https://doi.org/10.3390/machines12120929 - 18 Dec 2024

Abstract

In the field of material manufacturing, torsional vibration has some benefits for cutting or forming processing. In principle, torsional vibration can be caused by the torque ripples of a motor. Flux-switching permanent magnet (FSPM) motors are doubly salient and generate torque ripples, making [...] Read more.

In the field of material manufacturing, torsional vibration has some benefits for cutting or forming processing. In principle, torsional vibration can be caused by the torque ripples of a motor. Flux-switching permanent magnet (FSPM) motors are doubly salient and generate torque ripples, making them an option for manufacturing. However, the amplitude of the torque ripples is related to the motor structure, and frequency has a linear relationship with running speed. The torque ripples cannot be controlled separately from the motor running speed at conventional current excitations. Thus, a novel FSPM machine with an auxiliary rotor (AR-FSPM) is proposed to adjust the torque ripples. The main rotor (m-rotor) outputs the power, and the auxiliary rotor (a-rotor) adjusts the ripple frequency. When the speed difference between two rotors is six times the m-rotor speed, the torque ripple waveforms overlap. In this case, by controlling the phase difference between the two rotors, the amplitudes of the torque ripples can be adjusted. In this study, the principle of this novel machine is introduced, and the relationship between the torque ripple performance and the geometric parameters of the auxiliary rotor is studied. Then, the torque ripple amplitude adjustment method for this machine is discussed. Finally, the prototype of this novel machine is presented to verify its feasibility. Full article

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

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17 pages, 3973 KiB

Open AccessArticle

Multiple Electromechanical-Failure Detection in Induction Motor Using Thermographic Intensity Profile and Artificial Neural Network

by Emmanuel Resendiz-Ochoa, Salvador Calderon-Uribe, Luis A. Morales-Hernandez, Carlos A. Perez-Ramirez and Irving A. Cruz-Albarran

Machines 2024, 12(12), 928; https://doi.org/10.3390/machines12120928 - 17 Dec 2024

Abstract

The use of artificial intelligence-based techniques to solve engineering problems is increasing. One of the most challenging tasks facing industry is the timely diagnosis of failures in electromechanical systems, as they are an essential part of production systems. In this sense, the earlier [...] Read more.

The use of artificial intelligence-based techniques to solve engineering problems is increasing. One of the most challenging tasks facing industry is the timely diagnosis of failures in electromechanical systems, as they are an essential part of production systems. In this sense, the earlier the detection, the higher the economic loss reduction. For this reason, this work proposes the development of a new methodology based on infrared thermography and an artificial intelligence-based classifier for the detection of multiple faults in an electromechanical system. The proposal combines the intensity profile of the grey-scale image, the use of Fast Fourier Transform and an artificial neural network to perform the detection of twelve states for the state of an electromechanical system: healthy, bearing defect, broken rotor bar, misalignment and gear wear on the gearbox. From the experimental setup, 50 thermographic images were obtained for each state. The method was implemented and tested under different conditions to verify its reliability. The results show that the precision, accuracy, recall and F1-score are higher than 99%. Thus, it can be concluded that it is possible to detect multiple conditions in an electromechanical system using the intensity profile and an artificial neural network, achieving good accuracy and reliability. Full article

(This article belongs to the Special Issue Robust Control of Permanent Magnet Synchronous Motors (PMSM) and Induction Motors (IM))

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18 pages, 6851 KiB

Open AccessArticle

Research on a Bearing Fault Diagnosis Method Based on a CNN-LSTM-GRU Model

by Kaixu Han, Wenhao Wang and Jun Guo

Machines 2024, 12(12), 927; https://doi.org/10.3390/machines12120927 - 17 Dec 2024

Abstract

In view of the problem of the insufficient performance of deep learning models in time series prediction and poor comprehensive space–time feature extraction, this paper proposes a diagnostic method (CNN-LSTM-GRU) that integrates convolutional neural network (CNN), long short-term memory (LSTM) network, and gated [...] Read more.

In view of the problem of the insufficient performance of deep learning models in time series prediction and poor comprehensive space–time feature extraction, this paper proposes a diagnostic method (CNN-LSTM-GRU) that integrates convolutional neural network (CNN), long short-term memory (LSTM) network, and gated recurrent unit (GRU) models. In this study, a convolutional neural network (CNN) model is used to process two-dimensional image data in both time and frequency domains, and a convolutional core attention mechanism is introduced to extract spatial features, such as peaks, cliffs, and waveforms, from the samples. A long short-term memory (LSTM) network is embedded in the output processing of the convolutional neural network (CNN) to analyze the long-sequence variation characteristics of rolling bearing vibration signals and enable long-term time series prediction by capturing long-term dependencies in the sequence. In addition, a gated recurrent unit (GRU) is used to refine long-term time series predictions, providing local fine-tuning and improving the accuracy of fault diagnosis. Using a dataset obtained from Case Western Reserve University (CWRU), the average accuracy of CNN-LSTM-GRU fault vibration is greater than 99%, and its superior performance in a noisy environment is demonstrated. Full article

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

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31 pages, 13172 KiB

Open AccessArticle

Impact of Optimization Variables on Fuel Consumption in Large Four-Stroke Diesel Marine Engines with Electrically Divided Turbochargers

by Anibal Aguillon Salazar, Georges Salameh, Pascal Chesse, Nicolas Bulot and Yoann Thevenoux

Machines 2024, 12(12), 926; https://doi.org/10.3390/machines12120926 - 17 Dec 2024

Abstract

The objective of this study is to understand how each variable impacts the optimal configuration of a marine diesel engine equipped with an electric hybrid air-charging system that allows energy assistance and recovery. The aim is to minimize CO₂ emissions by reducing [...] Read more.

The objective of this study is to understand how each variable impacts the optimal configuration of a marine diesel engine equipped with an electric hybrid air-charging system that allows energy assistance and recovery. The aim is to minimize CO₂ emissions by reducing fuel consumption. The hybrid system offers flexibility in adjusting parameters from both the engine and air-charging system. It is compared with the baseline engine, which uses a free-floating turbocharger. The results show a significant improvement at low engine loads, where the baseline engine struggles to provide sufficient air. While turbine speed has little influence, compressor power reduces fuel consumption at low loads. However, at mid loads, resizing the turbomachine is necessary for further improvements. At high loads, full optimization of all variables is required to reduce fuel consumption. The electric hybrid system is particularly effective in tugboat-like conditions, where low loads dominate, but less impactful for ro-pax ferries. Despite the potential of the hybrid system, a fully optimized turbocharger could provide greater benefits due to reduced losses. Future studies could explore combining the adaptability of the hybrid system with a highly efficient turbocharger to reduce emissions across all load conditions. Full article

(This article belongs to the Special Issue Advanced Engine Energy Saving Technology)

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20 pages, 4533 KiB

Open AccessArticle

Kinematic Analysis of a Cam-Follower-Type Transplanting Mechanism for a 1.54 kW Biodegradable Potted Cabbage Transplanter

by Md Razob Ali, Md Nasim Reza, Samsuzzaman, Eliezel Habineza, Md Asrakul Haque, Beom-Sun Kang and Sun-Ok Chung

Machines 2024, 12(12), 925; https://doi.org/10.3390/machines12120925 - 17 Dec 2024

Abstract

Widespread use of plastic seedling pots has been attributed to their light weight and durable characteristics. However, these pots have limitations in facilitating efficient root establishment. Recent studies indicate that biodegradable seedling pots not only enhance seedling resilience but are also environmentally sustainable [...] Read more.

Widespread use of plastic seedling pots has been attributed to their light weight and durable characteristics. However, these pots have limitations in facilitating efficient root establishment. Recent studies indicate that biodegradable seedling pots not only enhance seedling resilience but are also environmentally sustainable through natural decomposition. This study presents a kinematic analysis of a cabbage transplanting mechanism specifically under development for biodegradable seedling pots, focusing on position, velocity, acceleration, and power. The optimization of link combinations within the transplanting mechanism was analyzed to enhance the transplantation process, focusing on achieving precise depth and spacing for potted seedlings. A kinematic model of the mechanism was developed and simulated using commercial mechanical design and simulation software, followed by validation through performance tests. The proposed transplanter comprised a four-bar-linkage mechanism consisting of a driving link, a driven link, a connecting link, and a guide bar. Simulation trials were conducted by varying the main arm link length while keeping machine forward speed and mechanism driving speed fixed. Results indicated that the optimal mechanism parameters included a driving link of 50 mm, a connecting arm of 120 mm, a guide bar of 120 mm, and an end-effector link of 220 mm. A dibbling hopper length of 153 mm was identified as the most effective for operation. With these recommended link lengths, validated velocities of the end hopper in the ‘X’ and ‘Y’ directions were 284 mm/s and 1379 mm/s, respectively, while corresponding accelerations were measured at 1241 mm/s² and 8664 mm/s². The driving power requirement was calculated to be 17.4 W. These findings suggest that the developed mechanism provides effective planting performance, evidenced by a high degree of seedling uprightness and minimal soil disturbance. This study supports the use of biodegradable pots in mechanized transplanting as a viable alternative to conventional plastic pots, with potential benefits for both agricultural efficiency and environmental sustainability. Full article

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

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