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Machines, Volume 11, Issue 6 (June 2023) – 93 articles

Cover Story (view full-size image): Design solutions of force-torque sensors can be conceived by using many types of connections or components; however, there are only a few sensors designed using cable-driven systems. In this paper, a new cable-driven model for under-actuated force-torque sensing mechanisms is proposed, simulated, and tested, underlining the novelty of using cables for force-torque sensing. The results confirm that the new proposed model can be used for force-torque sensing mechanisms in micro- and macro- applications where under-actuation is a fundamental requirement, as in robotic surgery. The innovative model is validated with two different test benches, opening new challenges in the design and development of under-actuated force-torque transducers. View this paper
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12 pages, 12010 KiB  
Communication
Developing an Interferogram-Based Module with Machine Learning for Maintaining Leveling of Glass Substrates
by Syuan-Cheng Chang, Chung-Ping Chang, Yung-Cheng Wang and Chi-Chieh Chu
Machines 2023, 11(6), 668; https://doi.org/10.3390/machines11060668 - 20 Jun 2023
Viewed by 1088
Abstract
In this research, we propose a method that utilizes machine learning to maintain the parallelism of the resonant cavity in a Fabry–Perot interferometer designed specifically for glass substrates. Based on the optical principle and theory, we establish a proportional relationship between interference fringes [...] Read more.
In this research, we propose a method that utilizes machine learning to maintain the parallelism of the resonant cavity in a Fabry–Perot interferometer designed specifically for glass substrates. Based on the optical principle and theory, we establish a proportional relationship between interference fringes and the inclination angle of the mirrors. This enables an accurate determination of the inclination angle using supervised learning, specifically classification. By training a machine learning model with labeled data, interference fringe patterns are categorized into three levels, with approximately 100 training data available for each level in each location. The experimental results of Level 2 and Level 3 classification indicate an average number of corrections of 2.55 and 3.55 times, respectively, in achieving the target position with a correction error of less than 30 arc seconds. These findings demonstrate the essential nature of this parallelism maintenance technology for the semiconductor industry and precision mechanical engineering. Full article
(This article belongs to the Section Machine Design and Theory)
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18 pages, 4579 KiB  
Article
Optimization of Outer Diameter Bernoulli Gripper with Cylindrical Nozzle
by Roman Mykhailyshyn, František Duchoň, Ivan Virgala, Peter Jan Sinčák and Ann Majewicz Fey
Machines 2023, 11(6), 667; https://doi.org/10.3390/machines11060667 - 20 Jun 2023
Cited by 3 | Viewed by 1162
Abstract
Gripping and manipulating objects using non-contact and low-contact technologies is becoming increasingly necessary in manufacturing. One of the promising contactless gripping technologies is Bernoulli gripping devices for industrial robots. They have many advantages, but when changing the nozzle geometry, it is difficult to [...] Read more.
Gripping and manipulating objects using non-contact and low-contact technologies is becoming increasingly necessary in manufacturing. One of the promising contactless gripping technologies is Bernoulli gripping devices for industrial robots. They have many advantages, but when changing the nozzle geometry, it is difficult to find the optimal parameters of the outer diameter of the gripper and its operating parameters. Therefore, the article presents a model for numerical simulation of the dynamics of airflow in the nozzle of the Bernoulli gripping device and in the radial gap between its active surface and the surface of the object of manipulation. Reynolds-averaged Navier–Stokes equations of viscous gas dynamics, SST-model of turbulence, and γ-model of laminar-turbulent transition were used for this purpose. The technical requirements for the design of the nozzle of Bernoulli jet gripping nozzles are determined and variants of their constructive improvement are offered. According to the results of numerical simulation in the Ansys-CFD software environment, the optimal diameter of the Bernoulli gripping device and the influence of the geometric parameters of the nozzle on the nature of the pressure distribution in the radial gap and its lifting force were determined. Determined the optimal parameters of the height of the gap between the object of manipulation and the Bernoulli gripping device using C—Factor, which will allow efficient operation of Bernoulli gripping devices during automated handling operations using industrial robots. Full article
(This article belongs to the Section Robotics, Mechatronics and Intelligent Machines)
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20 pages, 2160 KiB  
Article
Constrained Cost Fuzzy Control via Decentralized Design Approach for Nonlinear Descriptor Interconnected Systems
by Wen-Jer Chang, Che-Lun Su, Cheung-Chieh Ku and Chein-Chung Sun
Machines 2023, 11(6), 666; https://doi.org/10.3390/machines11060666 - 20 Jun 2023
Viewed by 711
Abstract
This paper proposes a decentralized robust constrained cost fuzzy controller (DRCCFC) design for nonlinear descriptor interconnected systems (DIS) with uncertainties. The considered nonlinear DIS is modeled using Takagi–Sugeno fuzzy model (T-S FM) with fuzzy rules and strong interconnections. To derive sufficient stability conditions, [...] Read more.
This paper proposes a decentralized robust constrained cost fuzzy controller (DRCCFC) design for nonlinear descriptor interconnected systems (DIS) with uncertainties. The considered nonlinear DIS is modeled using Takagi–Sugeno fuzzy model (T-S FM) with fuzzy rules and strong interconnections. To derive sufficient stability conditions, the quadratic Lyapunov function (QLF) and free-weighting function (FWF) are defined. In contrast to the existing control approaches, the proportional–derivative feedback (PDF) control is introduced in this paper. Using the PDF control techniques, the regular and causal problems of the system can be solved easily. Based on the PDF control technique and constrained cost control (CCC) function, a set of fuzzy controllers are designed to effectively control the Takagi–Sugeno descriptor interconnected systems (T-S DIS). Then, the proposed sufficient conditions for the T-S DIS are derived in the form of linear matrix inequalities using the Schur complement technique. Finally, two simulation examples are provided to demonstrate the validity of the proposed control scheme. Full article
(This article belongs to the Special Issue Advanced Methodology of Intelligent Control and Measurement)
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18 pages, 5245 KiB  
Article
Influence of Cutting Parameters and Tool Geometry on Topography of Hard Turned Surfaces
by Viktor Molnar
Machines 2023, 11(6), 665; https://doi.org/10.3390/machines11060665 - 20 Jun 2023
Cited by 1 | Viewed by 712
Abstract
Three-dimensional topography measurement is a focus area of precision machining because it provides detailed information on the functional behavior of contacting surfaces. The purpose of this study is to analyze how the process parameters and the edge geometry of the cutting insert influence [...] Read more.
Three-dimensional topography measurement is a focus area of precision machining because it provides detailed information on the functional behavior of contacting surfaces. The purpose of this study is to analyze how the process parameters and the edge geometry of the cutting insert influence the topographical characteristics of hardened 16MnCr5 steel surfaces and to determine the favorable combinations of technology parameter values based on the analyzed topography parameters (Ssk, Sku, Sz, Sa, Sk, Spk, Svk). A research question is whether the analyzed parameters can be substituted by each other or not. A hard turning experiment was carried out based on a full factorial design of experiments, and the areas of the machined surfaces were scanned and analyzed by analysis of variance, regression analysis (response function), and correlation analysis. It was found that there are strong correlations between the topography parameters that allow the substitution of one with another; the main influencing cutting parameter is the feed rate for both insert types. The contributions of the study are the numerical information with regard to the correlations among the topography parameters, as well as the extent of the influence of cutting parameters. Full article
(This article belongs to the Section Advanced Manufacturing)
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15 pages, 7028 KiB  
Article
A New Slurry for Photocatalysis-Assisted Chemical Mechanical Polishing of Monocrystal Diamond
by Junyong Shao, Yanjun Zhao, Jianhui Zhu, Zewei Yuan, Haiyang Du and Quan Wen
Machines 2023, 11(6), 664; https://doi.org/10.3390/machines11060664 - 20 Jun 2023
Viewed by 1152
Abstract
Diamond needs to have a perfectly smooth surface due to the growing requirements in the fields of electronic semiconductors, optical windows and high-fidelity loudspeakers. However, the polishing of diamonds is highly challenging due to their exceptional hardness and chemical stability. In this study, [...] Read more.
Diamond needs to have a perfectly smooth surface due to the growing requirements in the fields of electronic semiconductors, optical windows and high-fidelity loudspeakers. However, the polishing of diamonds is highly challenging due to their exceptional hardness and chemical stability. In this study, a new polishing slurry is prepared for the proposed photocatalysis-assisted chemical mechanical polishing (PCMP) approach to obtain an ultra-smooth surface for large-area diamond. The analyses and experimental findings revealed the significance of the photocatalyst, abrasive, electron capture agent and pH regulator as essential components of the PCMP slurry. TiO2 with a 5 nm pore size and P25 TiO2 possess improved photocatalysis efficiency. Moreover, diamond removal is smooth under the acidic environment of H3PO4 due to the high oxidation–reduction potential (ORP) of the slurry, and, during the methyl orange test, P25 TiO2 exhibits reasonable photocatalytic effects. Moreover, in 8 h, a smooth surface free of mechanical scratches can be obtained by reducing the surface roughness from Ra 33.6 nm to Ra 2.6 nm. Full article
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24 pages, 4797 KiB  
Article
Hardware-in-the-Loop Scheme of Linear Controllers Tuned through Genetic Algorithms for BLDC Motor Used in Electric Scooter under Variable Operation Conditions
by Leonardo Esteban Moreno-Suarez, Luis Morales-Velazquez, Arturo Yosimar Jaen-Cuellar and Roque Alfredo Osornio-Rios
Machines 2023, 11(6), 663; https://doi.org/10.3390/machines11060663 - 19 Jun 2023
Cited by 1 | Viewed by 1415
Abstract
Outrunner brushless DC motors (BLDC) are a type of permanent magnet synchronous motor (PMSM) widely used in electric micro-mobility vehicles, such as scooters, electric bicycles, wheelchairs, and segways, among others. Those vehicles have many operational constraints because they are driven directly by the [...] Read more.
Outrunner brushless DC motors (BLDC) are a type of permanent magnet synchronous motor (PMSM) widely used in electric micro-mobility vehicles, such as scooters, electric bicycles, wheelchairs, and segways, among others. Those vehicles have many operational constraints because they are driven directly by the user with light protective wearing. Therefore, to improve control strategies to make the drive safer, it is essential to model the traction system over a wide range of operating conditions in a street environment. In this work, we developed an electro-mechanical model based on the Hardware-in-the-Loop (HIL) structure for a two-wheeler electric scooter, using the BLDC motor to explore its response and to test linear controllers for speed and torque management under variable operating conditions. The proposed model includes motor parameters, power electronics component characteristics, mechanical structure, and external operating conditions. Meanwhile the linear controllers will be adjusted or tuned though a heuristic approach based on Genetic Algorithms (GAs) to optimize the system’s response. The HIL scheme will be able to simulate a wide range of conditions such as user weight, slopes, wind speed changes, and combined conditions. The designed model can be used to improve the design of the controller and estimate mechanical and electrical loads. Finally, the results of the controller tests show how the proposed cascade scheme, tuned through the GA, improves the system behavior and reduces the mean square error with respect to a classical tuning approach between 20% and 60%. Full article
(This article belongs to the Special Issue Condition-Based Monitoring of Electrical Machines)
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18 pages, 18905 KiB  
Article
Investigating the Stiffness Characteristics of a Tendon-Driven Continuum Manipulator Using Sensitivity Analysis: A Case Study in Transoral Laser Microsurgery
by Kapil Sawant, Antonios E. Gkikakis and Leonardo S. Mattos
Machines 2023, 11(6), 662; https://doi.org/10.3390/machines11060662 - 19 Jun 2023
Cited by 1 | Viewed by 1108
Abstract
Continuum manipulators, with their characteristics of flexibility and dexterity, have gained significant interest in various applications across industries such as inspection, manufacturing, space exploration, and medical surgery. However, because of their inherent compliance, handling payloads may prove challenging due to shape distortion and [...] Read more.
Continuum manipulators, with their characteristics of flexibility and dexterity, have gained significant interest in various applications across industries such as inspection, manufacturing, space exploration, and medical surgery. However, because of their inherent compliance, handling payloads may prove challenging due to shape distortion and deflection. This demonstrates the need to optimize the manipulator’s stiffness. The primary objective of this work was to show the merits of sensitivity analysis in the design of flexible surgical manipulators. Such analysis can guide important design decisions and enable the more efficient use of available resources, contributing to designing more effective prototypes. A new sensitivity analysis framework based on a multi-model and a multi-method approach was proposed to achieve this. This framework was then demonstrated by studying a tendon-driven rolling contact joint hyper-redundant manipulator for transoral laser microsurgery. In this analysis, the effects of independent design parameters on the stiffness of the manipulator were examined. Then, scaled-up 3D-printed prototypes were used to validate the accuracy of the stiffness model experimentally, which enabled us to assess the outcome of the sensitivity analysis framework. The results demonstrated that only two out of five design parameters for the considered manipulator significantly impacted the device’s performance. This information could enable the designer to efficiently allocate resources toward correctly setting these two most important parameters to achieve the desired system. Overall, the proposed analysis framework is a general tool that can be applied to any design architecture, helping to develop optimal manipulators for various applications. Full article
(This article belongs to the Special Issue Robots in Healthcare: Design, Control and Applications)
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23 pages, 16403 KiB  
Article
Investigation of the Uncoordinated Bolt Deformation of a Disc–Drum Combined Structure in a Turbine under Various Operating Conditions
by Haijun Wang and Pu Xue
Machines 2023, 11(6), 661; https://doi.org/10.3390/machines11060661 - 19 Jun 2023
Cited by 1 | Viewed by 812
Abstract
At high speeds and under large axial forces, the disc–drum combined structure exhibits inconsistent deformation between parts. The difference in the structural characteristics of different parts, the speed, the preload, and its distribution mode, along with other factors, make the deformation of parts [...] Read more.
At high speeds and under large axial forces, the disc–drum combined structure exhibits inconsistent deformation between parts. The difference in the structural characteristics of different parts, the speed, the preload, and its distribution mode, along with other factors, make the deformation of parts more complex, resulting in the deformation of parts during work; this deformation inconsistency has a direct impact on the engine performance. This paper presents a systemic investigation of the uncoordinated bolt deformation of an aeroengine. The finite element model of the disc–drum combined structure is established using Ansys workbench, where the deformation is uncoordinated. On this basis, the influence of different preload forces and various rotation speeds on the deformation discordance of the combined structure are discussed. Then, the relationship between the bolt deformation and component deformation incompatibility is obtained through a comprehensive analysis of the bolt deformation. A set of detailed analyses was carried out to investigate the uncoordinated deformation caused by the uneven distribution of the preload force. Full article
(This article belongs to the Section Turbomachinery)
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16 pages, 11876 KiB  
Article
Experimental Research on the Formation of the Third Body on the Friction Surface of Coal Cake Tamper Hammer Lifting Mechanism
by Lin Huang, Shengfang Zhang, Bingtao Qin, Yu Liu and Zhihua Sha
Machines 2023, 11(6), 660; https://doi.org/10.3390/machines11060660 - 19 Jun 2023
Viewed by 643
Abstract
A tamping machine is the key equipment of large coking coal cake forming in the steelmaking industry, where the loose coal is compacted into a coal cake by the reciprocating movement of its tamping hammer. In the long-term friction process, the third particle [...] Read more.
A tamping machine is the key equipment of large coking coal cake forming in the steelmaking industry, where the loose coal is compacted into a coal cake by the reciprocating movement of its tamping hammer. In the long-term friction process, the third particle attached to the surface of the friction pair of the hammer lifting mechanism often causes the tamping hammer to slip and wear the tamping hammer friction plate, resulting in an insufficient height of the hammer, uneven work of the tamping hammer, coal cake collapse and other problems. In order to avoid the adverse effect of the third body on the surface of the friction pair, this paper studies the formation of the third body on the friction surface of the lifting hammer mechanism of the coal cake tamper. The cam material (Q345B) of the hammer lifting mechanism and the copper-based powder-metallurgy composite material of the friction plate of the tamping hammer are prepared into the pin-disk friction test disk and pin, respectively. Based on the characteristics of the friction temperature variation in the pin-disk test, an equivalent accumulation method is proposed, that is, the wear state of several samples at different wear times is equivalent to characterize the wear condition of a sample at different stages during continuous wear, and the different stages of the third body formation process are obtained. By analyzing the change of the composition of the third body and the content proportion of each element on the surface of the bottom plate at different wear times, it is determined that Cu is the key index of the third body. The content of the Cu element is used to characterize the content of the third body on the surface of the disk sample, and the formation rule of the third body on the surface of the disk is inferred. Through an image processing method of color analysis, the distribution law of the third body on the whole disk is identified. The properties of the third-body material on the disk surface are obtained by analyzing the changes of hardness and morphology at each friction stage. The results show that with the increase of friction time, the content of Cu on the disk surface increases to 22% and then decreases to 15%. The microhardness of the friction surface reaches its highest at 7 min, which is 1.4 times that of the Q345B material. The maximum disk surface roughness is 0.452 µm. Finally, the formation process of the third body is summarized in three stages: formation, equilibrium and damage. Therefore, the frictional properties of the surface of the friction pair vary from weak to strong to weak with the formation characteristics of the third body. Full article
(This article belongs to the Section Friction and Tribology)
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21 pages, 21624 KiB  
Article
Field Complete Coverage Path Planning Based on Improved Genetic Algorithm for Transplanting Robot
by Xizhi Wu, Jinqiang Bai, Fengqi Hao, Guanghe Cheng, Yongwei Tang and Xiuhua Li
Machines 2023, 11(6), 659; https://doi.org/10.3390/machines11060659 - 19 Jun 2023
Cited by 3 | Viewed by 1435
Abstract
The Complete Coverage Path Planning (CCPP) is a key technology in the field of agricultural robots, and has great significance for improving the efficiency and quality of tillage, fertilization, harvesting, and other agricultural robot operations, as well as reducing the operation energy consumption. [...] Read more.
The Complete Coverage Path Planning (CCPP) is a key technology in the field of agricultural robots, and has great significance for improving the efficiency and quality of tillage, fertilization, harvesting, and other agricultural robot operations, as well as reducing the operation energy consumption. The traditional boustrophedon- or heuristic-search-algorithm-based CCPP methods, when coping with the field with irregular boundaries, obstacles, and other complex environments, still face many problems and challenges, such as large repeated work areas, multiple turns or U-turns, low operation efficiency, and prone to local optimum. In order to solve the above problems, an improved-genetic-algorithm-based CCPP method was proposed in this paper, the proposed method innovatively extends the traditional genetic algorithm’s chromosomes and single-point mutation into chromosome pairs and multi-point mutation, and proposed a multi-objective equilibrium fitness function. The simulation and experimental results on simple regular fields showed that the proposed improved-genetic-algorithm-based CCPP method achieved the comparable performance with the traditional boustrophedon-based CCPP method. However, on the complex irregular fields, the proposed CCPP method reduces 38.54% of repeated operation area and 35.00% of number of U-turns, and can save 7.82% of energy consumption on average. This proved that the proposed CCPP method has a strong adaptive capacity to the environment, and has practical application value in improving the efficiency and quality of agricultural machinery operations, and reducing the energy consumption. Full article
(This article belongs to the Special Issue Advanced Control and Robotic System in Path Planning)
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15 pages, 5487 KiB  
Article
Comparison of Modeling Methods for Off-Road Tires
by Dávid Körmöczi and Péter Kiss
Machines 2023, 11(6), 658; https://doi.org/10.3390/machines11060658 - 19 Jun 2023
Viewed by 864
Abstract
Efficient navigation of off-road vehicles heavily relies on the ability to accurately model the interaction between the vehicle and the terrain. One of the most important parts of this interaction is the deformation of the terrain and the tire. Although high-precision methods like [...] Read more.
Efficient navigation of off-road vehicles heavily relies on the ability to accurately model the interaction between the vehicle and the terrain. One of the most important parts of this interaction is the deformation of the terrain and the tire. Although high-precision methods like finite element method (FEM) simulation can be used for this purpose, they require significant computational power, which is impractical to install in a vehicle for real-time navigation purposes. Therefore, simplified and less-detailed models are essential for on-board installation in real-time applications. In this study, three two-dimensional static terrain–vehicle models are compared to a detailed FEM reference model, and the results are evaluated both from the perspective of accuracy and computational capacity requirements. The analysis sheds light on the effectiveness of each model in the real-time navigation of off-road vehicles. Full article
(This article belongs to the Section Vehicle Engineering)
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20 pages, 10179 KiB  
Article
Numerical Simulations of the Driving Process of a Wheeled Machine Tire on a Snow-Covered Road
by Di Wang, Hui Wang, Yan Xu, Jianpin Zhou and Xinyu Sui
Machines 2023, 11(6), 657; https://doi.org/10.3390/machines11060657 - 18 Jun 2023
Viewed by 1290
Abstract
Wheeled machines, such as agricultural tractors, snowplows, and wheeled mobile robots, usually work on icy or snow-covered roads. Therefore, it is very important to study the driving and slip resistance of the tires of these machines. In this paper, we investigate the driving [...] Read more.
Wheeled machines, such as agricultural tractors, snowplows, and wheeled mobile robots, usually work on icy or snow-covered roads. Therefore, it is very important to study the driving and slip resistance of the tires of these machines. In this paper, we investigate the driving behavior of tires on snow-covered terrain by means of numerical simulations. A high-fidelity snow-covered road model is established, and smoothed particle hydrodynamics (SPH) and the finite element method (FEM) are employed to account for the behaviors of the snow layers and the pavement, respectively. We use the node-to-surface algorithm for the contact interactions between the snow and the pavement. The SPH parameters for the snow are calibrated by means of a triaxial compression experiment. A simplified tire model is established as well, using the FEM, and the effectiveness of the model is demonstrated via comparisons with the experimental data in terms of stiffness. Finally, the tire driving performance on the snow-covered road is simulated, and the influence of the tire surface configuration, external load, inflation pressure, and snowpack compression on the tire traction behaviors is systematically investigated. Full article
(This article belongs to the Section Vehicle Engineering)
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17 pages, 4093 KiB  
Article
Speed Regulation and Optimization of Sensorless System of Permanent Magnet Synchronous Motor
by Yan Zhang, Huacai Lu, Minghu Li and Xiang Liu
Machines 2023, 11(6), 656; https://doi.org/10.3390/machines11060656 - 18 Jun 2023
Viewed by 784
Abstract
Aiming at the problems of speed overshoot, slow convergence and poor anti-interference in the control of permanent-magnet synchronous motors (PMSMs) without a position sensor, a pulse vibration high-frequency signal injection method for a permanent-magnet synchronous motor with an improved sliding mode control was [...] Read more.
Aiming at the problems of speed overshoot, slow convergence and poor anti-interference in the control of permanent-magnet synchronous motors (PMSMs) without a position sensor, a pulse vibration high-frequency signal injection method for a permanent-magnet synchronous motor with an improved sliding mode control was designed. Firstly, the improved approach rate function is combined with the improved non-singular fast terminal sliding mode surface to design the non-singular fast terminal sliding mode controller (NFTSMC), which is used in the speed loop to improve the speed convergence ability and reduce its overshoot. Secondly, in order to eliminate the influence of the band-pass filter on the system bandwidth in the traditional high-frequency injection method, a pulse vibration high-frequency signal injection method that injects high-frequency voltage signals and synchronous current signals into the d^ axis of the estimated two-phase rotation coordinate system d^q^ and the αβ axis of the two-phase stationary coordinate system αβ was designed to estimate the motor position and speed to achieve sensorless control. Finally, the above control strategy was compared with the speed loop PI and the traditional sliding mode controller (SMC) of the speed loop, respectively. The simulation and experimental results show that whether it is a no-load variable speed or fixed speed loading, the above control strategy can effectively reduce the speed overshoot, accelerate the speed convergence and improve the load capacity of the system. Full article
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17 pages, 8263 KiB  
Article
Experimental Investigation and Modeling of Force-Induced Surface Errors for the Robot-Assisted Milling Process
by Yongqiao Jin, Qunfei Gu, Shun Liu and Changqi Yang
Machines 2023, 11(6), 655; https://doi.org/10.3390/machines11060655 - 18 Jun 2023
Cited by 1 | Viewed by 1021
Abstract
A series of experiments were performed aiming at controlling milling force-induced surface errors in the robot-assisted milling process, for the sub-area of the multi-stiffener reinforced inner wall of complex cylindrical thin-walled casting parts, to investigate the relationship between surface errors, milling forces, and [...] Read more.
A series of experiments were performed aiming at controlling milling force-induced surface errors in the robot-assisted milling process, for the sub-area of the multi-stiffener reinforced inner wall of complex cylindrical thin-walled casting parts, to investigate the relationship between surface errors, milling forces, and robot-assisted milling parameters. Firstly, based on the design of experiments (DoE) method, milling forces and surface errors were investigated based on a series of experiments with different groups of milling parameters. Secondly, the modeling of milling forces, surface errors, and milling parameters was realized by means of response surface methodology (RSM), then the parametric expression was obtained of the robot-assisted milling process. Finally, the parameters of the milling process toward the surface error were obtained based on an evolutionary algorithm. The results show that the surface errors are different for the different milling styles of down milling and up milling. In up milling processes, the surface errors are positive, and the actual material removal amounts are generally higher than the nominal ones, while negative in down milling processes. The surface errors induced by milling forces can be effectively controlled and reduced using process optimization in the robot-assisted milling process, while maintaining relatively high milling forces and high machining efficiency. This provides theoretical support for industry applications. Full article
(This article belongs to the Special Issue Advanced Manufacturing and Quality Control for Engines)
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21 pages, 4739 KiB  
Article
Tires and Vehicle Lateral Dynamic Performance: A Corrective Algorithm for the Influence of Temperature
by Simone Savant, Henrique De Carvalho Pinheiro, Matteo Eugenio Sacchi, Cinzia Conti and Massimiliana Carello
Machines 2023, 11(6), 654; https://doi.org/10.3390/machines11060654 - 17 Jun 2023
Cited by 1 | Viewed by 1412
Abstract
The automotive industry is experiencing increasing competition, and vehicle development is becoming increasingly complex. Manufacturers must therefore be able to rapidly compare the outcomes of experimental tests carried out under different conditions. Robust simulation tools that can adjust for external factors have the [...] Read more.
The automotive industry is experiencing increasing competition, and vehicle development is becoming increasingly complex. Manufacturers must therefore be able to rapidly compare the outcomes of experimental tests carried out under different conditions. Robust simulation tools that can adjust for external factors have the potential to save a significant amount of time. In this regard, the purpose of this paper is to propose a method for evaluating the effect of asphalt temperature on tire and vehicle lateral dynamic performance, based on empirical data. Because rubber is a viscoelastic material, its properties are heavily influenced by the operating conditions. Therefore, a corrective algorithm must be created to enable the transfer of results obtained from tests carried out under different asphalt temperature conditions to a reference temperature of 25 °C. This article presents an analytical model that accurately describes this phenomenon, as well as the methods employed to generalize and optimize the model. Generalizability represents a crucial aspect of this research, as the model must be widely applicable across several vehicle categories while requiring minimal data to perform the corrections effectively. Finally, the analytical compensatory tool was incorporated into a MATLAB bicycle model to update the numerical transfer function measurements that describe the vehicle’s dynamic behavior during experimental maneuvers. These results indicate that modest data is needed to achieve good levels of accuracy, making the model and vehicle dynamics implementation promising. Full article
(This article belongs to the Topic Vehicle Dynamics and Control)
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74 pages, 8142 KiB  
Review
Overview of Multi-Robot Collaborative SLAM from the Perspective of Data Fusion
by Weifeng Chen, Xiyang Wang, Shanping Gao, Guangtao Shang, Chengjun Zhou, Zhenxiong Li, Chonghui Xu and Kai Hu
Machines 2023, 11(6), 653; https://doi.org/10.3390/machines11060653 - 17 Jun 2023
Cited by 1 | Viewed by 3411
Abstract
In the face of large-scale environmental mapping requirements, through the use of lightweight and inexpensive robot groups to perceive the environment, the multi-robot cooperative (V)SLAM scheme can resolve the individual cost, global error accumulation, computational load, and risk concentration problems faced by single-robot [...] Read more.
In the face of large-scale environmental mapping requirements, through the use of lightweight and inexpensive robot groups to perceive the environment, the multi-robot cooperative (V)SLAM scheme can resolve the individual cost, global error accumulation, computational load, and risk concentration problems faced by single-robot SLAM schemes. Such schemes are robust and stable, form a current research hotspot, and relevant algorithms are being updated rapidly. In order to enable the reader to understand the development of this field rapidly and fully, this paper provides a comprehensive review. First, the development history of multi-robot collaborative SLAM is reviewed. Second, the fusion algorithms and architectures are detailed. Third, from the perspective of machine learning classification, the existing algorithms in this field are discussed, including the latest updates. All of this will make it easier for readers to discover problems that need to be studied further. Finally, future research prospects are listed. Full article
(This article belongs to the Section Automation and Control Systems)
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19 pages, 5883 KiB  
Article
Dynamic Modeling and Performance Evaluation of a 5-DOF Hybrid Robot for Composite Material Machining
by Xiaojian Wang, Jun Wu and Yulin Zhou
Machines 2023, 11(6), 652; https://doi.org/10.3390/machines11060652 - 16 Jun 2023
Viewed by 841
Abstract
Dynamic performance is an important performance of robots used for machine processing. This paper studies the dynamic modeling and evaluation method of a 5-DOF (Degree of Freedom) hybrid robot used in aerospace composite material processing. With the consideration of the dynamics of the [...] Read more.
Dynamic performance is an important performance of robots used for machine processing. This paper studies the dynamic modeling and evaluation method of a 5-DOF (Degree of Freedom) hybrid robot used in aerospace composite material processing. With the consideration of the dynamics of the serial part, the complete dynamic model of the hybrid robot is established based on the virtual work principle. In addition to the widely considered acceleration term, a dynamic performance evaluation index that comprehensively considers the acceleration term, velocity term and gravity term in the dynamic model is proposed. Using the dynamic performance index, the effect of the placement direction of the robot and the arrangement of the double symmetric limbs on robot dynamics are investigated. The results indicate that the vertical placement is beneficial to the dynamics of the hybrid robot, and the arrangement of double symmetric limbs has different effects on different limbs. Full article
(This article belongs to the Special Issue Advances in Parallel Robots and Mechanisms)
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13 pages, 4154 KiB  
Article
Knock Mitigation and Power Enhancement of Hydrogen Spark-Ignition Engine through Ammonia Blending
by Haiwen Ge, Ahmad Hadi Bakir and Peng Zhao
Machines 2023, 11(6), 651; https://doi.org/10.3390/machines11060651 - 16 Jun 2023
Cited by 4 | Viewed by 1330
Abstract
Hydrogen and ammonia are primary carbon-free fuels that have massive production potential. In regard to their flame properties, these two fuels largely represent the two extremes among all fuels. The extremely fast flame speed of hydrogen can lead to an easy deflagration-to-detonation transition [...] Read more.
Hydrogen and ammonia are primary carbon-free fuels that have massive production potential. In regard to their flame properties, these two fuels largely represent the two extremes among all fuels. The extremely fast flame speed of hydrogen can lead to an easy deflagration-to-detonation transition and cause detonation-type engine knock that limits the global equivalence ratio, and consequently the engine power. The very low flame speed and reactivity of ammonia can lead to a low heat release rate and cause difficulty in ignition and ammonia slip. Adding ammonia into hydrogen can effectively modulate flame speed and hence the heat release rate, which in turn mitigates engine knock and retains the zero-carbon nature of the system. However, a key issue that remains unclear is the blending ratio of NH3 that provides the desired heat release rate, emission level, and engine power. In the present work, a 3D computational combustion study is conducted to search for the optimal hydrogen/ammonia mixture that is knock-free and meanwhile allows sufficient power in a typical spark-ignition engine configuration. Parametric studies with varying global equivalence ratios and hydrogen/ammonia blends are conducted. The results show that with added ammonia, engine knock can be avoided, even under stoichiometric operating conditions. Due to the increased global equivalence ratio and added ammonia, the energy content of trapped charge as well as work output per cycle is increased. About 90% of the work output of a pure gasoline engine under the same conditions can be reached by hydrogen/ammonia blends. The work shows great potential of blended fuel or hydrogen/ammonia dual fuel in high-speed SI engines. Full article
(This article belongs to the Special Issue Advances in Combustion Science for Future IC Engines)
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12 pages, 3864 KiB  
Article
Attitude-Oriented Stability Control with Adaptive Impedance Control for a Wheeled Robotic System on Rough Terrain
by Kang Xu, Jianyong Li, Jinge Si, Yueming Liu and Meng Nie
Machines 2023, 11(6), 650; https://doi.org/10.3390/machines11060650 - 15 Jun 2023
Viewed by 903
Abstract
Base stability for a wheeled robot while driving over rough terrain is a challenging issue. This paper proposes a novel base-stability control framework, consisting of an AVIC (adaptive variable-impedance control), AVIC-based tracking controller, and a THV (terrain height variation) and AC (attitude control) [...] Read more.
Base stability for a wheeled robot while driving over rough terrain is a challenging issue. This paper proposes a novel base-stability control framework, consisting of an AVIC (adaptive variable-impedance control), AVIC-based tracking controller, and a THV (terrain height variation) and AC (attitude control) AC-based controller to stabilize the base on rough terrain. The AVIC-based controller aims to track the desired trajectory of the robot base while suppressing lumped disturbance, including system uncertainties in the internal dynamics and unknown external disturbance. The THV-based controller is utilized as a feedforward controller to improve posture tracking performance in order to achieve a horizontal posture. The AC-based controller is employed to maintain the horizontal posture of the base. The effectiveness and robustness of the proposed controllers are validated by a series of numerical trials, and the results are evaluated. Full article
(This article belongs to the Section Automation and Control Systems)
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18 pages, 2955 KiB  
Article
The Friction of Radially Loaded Hybrid Spindle Bearings under High Speeds
by Marcus Gärtner, Christian Brecher, Stephan Neus, Hans-Martin Eckel, Andreas Bartelt, Maik Hoppert and Mohammad Reza Ilkhani
Machines 2023, 11(6), 649; https://doi.org/10.3390/machines11060649 - 15 Jun 2023
Viewed by 996
Abstract
Friction losses are an important parameter for evaluating the operational behaviour of high-speed rolling bearings. Specifically, in machine tool applications, the bearings are subjected to high radial loads and high speeds, which lead to increased forces in the rolling contact and, as a [...] Read more.
Friction losses are an important parameter for evaluating the operational behaviour of high-speed rolling bearings. Specifically, in machine tool applications, the bearings are subjected to high radial loads and high speeds, which lead to increased forces in the rolling contact and, as a result, increased bearing friction. In this high-speed application, hybrid spindle bearings, typically made of ceramic balls and steel raceways, show better frictional behaviour compared to full steel-made bearings. Therefore, precise knowledge of the friction characteristics of high-speed hybrid bearings can improve friction models and generalise them to spindle bearings with different types, geometries, and operating conditions. In this article, a new straightforward and cost-efficient method for measuring the frictional torque in spindle bearings is presented. A rigidly arranged 7008 hybrid spindle bearing pair was tested up to rotational speeds of 24,000 rpm and high radial loads of 3 kN. The effects of oil–air and grease lubrication are discussed in characteristic diagrams of the tested bearings. Then, based on the test results, a friction calculation model is presented and validated for the outer race control and minimised power dissipation regarding the influence of radial forces. Full article
(This article belongs to the Special Issue Rotor Dynamics and Rotating Machinery)
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33 pages, 72432 KiB  
Article
Inverse Kinematics of Robot Manipulator Based on BODE-CS Algorithm
by Minghao Li, Xiao Luo and Lijun Qiao
Machines 2023, 11(6), 648; https://doi.org/10.3390/machines11060648 - 14 Jun 2023
Cited by 1 | Viewed by 1092
Abstract
Differential evolution is a popular algorithm for solving global optimization problems. When tested, it has reportedly outperformed both robotic problems and benchmarks. However, it may have issues with local optima or premature convergence. In this paper, we present a novel BODE-CS (Bidirectional Opposite [...] Read more.
Differential evolution is a popular algorithm for solving global optimization problems. When tested, it has reportedly outperformed both robotic problems and benchmarks. However, it may have issues with local optima or premature convergence. In this paper, we present a novel BODE-CS (Bidirectional Opposite Differential Evolution–Cuckoo Search) algorithm to solve the inverse kinematics problem of a six-DOF EOD (Explosive Ordnance Disposal) robot manipulator. The hybrid algorithm was based on the differential evolution algorithm and Cuckoo Search algorithm. To avoid any local optimum and accelerate the convergence of the swarm, various strategies were introduced. Firstly, a forward-kinematics model was established, and the objective function was formulated according to the structural characteristics of the robot manipulator. Secondly, a Halton sequence and an opposite search strategy were used to initialize the individuals in the swarm. Thirdly, the optimization algorithms applied to the swarm were dynamically allocated to the Differential Evolution algorithm or the Cuckoo algorithm. Fourthly, a composite differential algorithm, which consisted of a dynamically opposite differential strategy, a bidirectional search strategy, and two other typically used differential strategies were introduced to maintain the diversity of the swarm. Finally, two adaptive parameters were introduced to optimize the amplification factor F and cross-over probability Cr. To verify the performance of the BODE-CS algorithm, two different tasks were tested. The experimental results of the simulation showed that the BODE-CS algorithm had high accuracy and a fast convergence rate, which met the requirements of an inverse solution for the manipulator. Full article
(This article belongs to the Section Robotics, Mechatronics and Intelligent Machines)
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19 pages, 8229 KiB  
Article
The Neutral Voltage Difference Signal as a Means of Investigating Eccentricity and Demagnetization Faults in an AFPM Synchronous Generator
by Alexandra C. Barmpatza
Machines 2023, 11(6), 647; https://doi.org/10.3390/machines11060647 - 14 Jun 2023
Cited by 2 | Viewed by 927
Abstract
This article investigates the neutral voltage difference signal, VNO signal, for fault diagnosis. The aforementioned signal is the signal of the voltage between the common star point of the stator and the common star point of the load. The under-study faults are [...] Read more.
This article investigates the neutral voltage difference signal, VNO signal, for fault diagnosis. The aforementioned signal is the signal of the voltage between the common star point of the stator and the common star point of the load. The under-study faults are demagnetization and static eccentricity faults, while the machine in which the faults are investigated is an axial flux permanent magnet (AFPM) synchronous generator, suitable for wind power applications. This study was conducted using a 3D finite element method (3D-FEM), and the machine’s FEM model was validated through experiments. This method is one of the most accurate methods for electrical machine computation, allowing for a detailed study of electromagnetic behavior. The components that constitute the VNO signal were determined using a 3D-FEM software program (Opera 18R2). Subsequently, further analysis was performed using MATLAB R2022b software, and a fast Fourier transform (FFT) was applied to this signal. In all the investigated faulty cases, new harmonics appeared, and the healthy amplitudes of most of the already existing harmonics increased. These findings can be used for fault identification. The analysis revealed that the harmonic frequency of 1.5fs was the most dominant in the case of demagnetization, while in the case of static eccentricity, the most dominant harmonic was a frequency equal to the machine’s operating frequency, fs. The novelty of this study is that this signal has not previously been used for fault identification, especially in AFPM synchronous machines. This signal depends on EMF voltage and stator phase currents but is less sinusoidal. Consequently, it can detect faults in cases where the aforementioned signals cannot be used for detection. Full article
(This article belongs to the Section Electrical Machines and Drives)
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24 pages, 9272 KiB  
Article
Gearbox Fault Diagnosis Based on Refined Time-Shift Multiscale Reverse Dispersion Entropy and Optimised Support Vector Machine
by Xiang Wang and Han Jiang
Machines 2023, 11(6), 646; https://doi.org/10.3390/machines11060646 - 13 Jun 2023
Viewed by 954
Abstract
The fault diagnosis of a gearbox is crucial to ensure its safe operation. Entropy has become a common tool for measuring the complexity of time series. However, entropy bias may occur when the data are not long enough or the scale becomes larger. [...] Read more.
The fault diagnosis of a gearbox is crucial to ensure its safe operation. Entropy has become a common tool for measuring the complexity of time series. However, entropy bias may occur when the data are not long enough or the scale becomes larger. This paper proposes a gearbox fault diagnosis method based on Refined Time-Shifted Multiscale Reverse Dispersion Entropy (RTSMRDE), t-distributed Stochastic Neighbour Embedding (t-SNE), and the Sparrow Search Algorithm Support Vector Machine (SSA-SVM). First, the proposed RTSMRDE was used to calculate the multiscale fault features. By incorporating the refined time-shift method into Multiscale Reverse Dispersion Entropy (MRDE), errors that arose during the processing of complex time series could be effectively reduced. Second, the t-SNE algorithm was utilized to extract sensitive features from the multiscale, high-dimensional fault features. Finally, the low-dimensional feature matrix was input into SSA-SVM for fault diagnosis. Two gearbox experiments showed that the diagnostic model proposed in this paper had an accuracy rate of 100%, and the proposed model performed better than other methods in terms of diagnostic performance. Full article
(This article belongs to the Special Issue Vibration Analysis for Structural Health Monitoring)
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18 pages, 4927 KiB  
Article
Experimental Study and GRNN Modeling of Shrinkage Characteristics for Wax Patterns of Gas Turbine Blades Considering the Influence of Complex Structures
by Changhui Liu, Chenghong Jiang, Zhenfeng Zhou, Fei Li, Donghong Wang and Sansan Shuai
Machines 2023, 11(6), 645; https://doi.org/10.3390/machines11060645 - 13 Jun 2023
Viewed by 777
Abstract
With the continuous increase in power demand in aerospace, shipping, electricity, and other industries, a series of manufacturing requirements such as high precision, complex structure, and thin wall have been put forward for gas turbines. Gas turbine blades are the key parts of [...] Read more.
With the continuous increase in power demand in aerospace, shipping, electricity, and other industries, a series of manufacturing requirements such as high precision, complex structure, and thin wall have been put forward for gas turbines. Gas turbine blades are the key parts of the gas turbine. Their manufacturing accuracy directly affects the fuel economy of the gas turbine. Thus, how to improve the manufacturing accuracy of gas turbine blades has always been a hot research topic. In this study, we perform a quantitative study on the correlation between process parameters and the overall wax pattern shrinkage of gas turbine blades in the wax injection process. A prediction model based on a generalized regression neural network (GRNN) is developed with the newly defined cross-sectional features consisting of area, area ratio, and some discrete point deviations. In the qualitative analysis of the cross-sectional features, it is concluded that the highest accuracy of the wax pattern is obtained for the fourth group of experiments, which corresponds to a holding pressure of 18 bars, a holding time of 180 s, and an injection temperature of 62 °C. The prediction model is trained and tested based on small experimental data, resulting in an average RE of 1.5% for the area, an average RE of 0.58% for the area ratio, and a maximum MSE of less than 0.06  mm2 for discrete point deviations. Experiments show that the GRNN prediction model constructed in this study is relatively accurate, which means that the shrinkage of the remaining major investment casting procedures can also be modeled and controlled separately to obtain turbine blades with higher accuracy. Full article
(This article belongs to the Special Issue Advanced Manufacturing and Quality Control for Engines)
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22 pages, 7117 KiB  
Article
Turning Chatter Detection Using a Multi-Input Convolutional Neural Network via Image and Sound Signal
by Quang Ngoc The Ho, Thanh Trung Do, Pham Son Minh, Van-Thuc Nguyen and Van Thanh Tien Nguyen
Machines 2023, 11(6), 644; https://doi.org/10.3390/machines11060644 - 13 Jun 2023
Cited by 3 | Viewed by 1295
Abstract
In mechanical cutting and machining, self-excited vibration known as “Chatter” often occurs, adversely affecting a product’s quality and tool life. This article proposes a method to identify chatter by applying a machine learning model to classify data, determining whether the machining process is [...] Read more.
In mechanical cutting and machining, self-excited vibration known as “Chatter” often occurs, adversely affecting a product’s quality and tool life. This article proposes a method to identify chatter by applying a machine learning model to classify data, determining whether the machining process is stable or vibrational. Previously, research studies have used detailed surface image data and sound generated during the machining process. To increase the specificity of the research data, we constructed a two-input model that enables the inclusion of both acoustic and visual data into the model. Data for training, testing, and calibration were collected from machining flanges SS400 in the form of thin steel sheets, using electron microscopes for imaging and microphones for sound recording. The study also compares the accuracy of the two-input model with popular models such as a visual geometry group network (VGG16), residual network (Restnet50), dense convolutional network (DenseNet), and Inception network (InceptionNet). The results show that the DenseNet model has the highest accuracy of 98.8%, while the two-input model has a 98% higher accuracy than other models; however, the two-input model is more appreciated due to the generality of the input data of the model. Experimental results show that the recommended model has good results in this work. Full article
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15 pages, 10125 KiB  
Article
Dynamic Characteristics of a Rotating Blade with a Dovetail Fixture
by Xiaoyu Fan, Wenchao Liang, Jin Zeng, Yang Yang, Hui Ma, Chenguang Fan and Shunguo Fu
Machines 2023, 11(6), 643; https://doi.org/10.3390/machines11060643 - 12 Jun 2023
Viewed by 984
Abstract
Considering rotation-induced centrifugal stiffening, spin softening, and Coriolis effects, the reduced dynamic model of a rotating blade with a dovetail fixture is established in the ANSYS environment via the fixed-interface method for higher computational efficiency and lower memory consumption. Then some parameters such [...] Read more.
Considering rotation-induced centrifugal stiffening, spin softening, and Coriolis effects, the reduced dynamic model of a rotating blade with a dovetail fixture is established in the ANSYS environment via the fixed-interface method for higher computational efficiency and lower memory consumption. Then some parameters such as rotating speed, friction factor, and stator blade number affecting the nonlinear vibration responses of the system under the combined actions of aerodynamic force, centrifugal force, and gravity are elaborately discussed. The results show that: (1) the contact-induced nonlinearity between the tenon and the mortise mainly results in the frequency multiplications of the aerodynamic excitation frequency; (2) a larger friction factor results in a lower magnitude of contact pressure and a higher resonance frequency, while a larger stator blade number results in a lower magnitude of the uniform and continuous contact pressure distribution; (3) the excitation of the resonant mode caused by the aerodynamic force is primarily characterized by the first-order bending mode of the system. Full article
(This article belongs to the Special Issue Research on Rotor Dynamics and Vibration Control)
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25 pages, 8630 KiB  
Article
Design of Vibrating Systems Using Solution Spaces
by Duo Xu, Yunzhe Zhang and Markus Zimmermann
Machines 2023, 11(6), 642; https://doi.org/10.3390/machines11060642 - 12 Jun 2023
Viewed by 936
Abstract
Due to complex component interactions and multidisciplinary and possibly conflicting requirements, it is challenging to identify appropriate design goals for individual components to keep the vibration of a mechanical system below a specified level. Existing development methods are limited in that they only [...] Read more.
Due to complex component interactions and multidisciplinary and possibly conflicting requirements, it is challenging to identify appropriate design goals for individual components to keep the vibration of a mechanical system below a specified level. Existing development methods are limited in that they only provide precise component targets without tolerance. Tolerance is required, however, for reconciling conflicting requirements and to provide freedom for component design. This paper presents a systematic design method for vibrating systems based on so-called solution spaces. It consists of (1) system modeling, (2) solution space computation, (3) component modeling and (4) detailed design. Solution spaces are admissible value ranges and serve as component requirements that guide independent component design. Meeting these component requirements guarantees that the overall system design goal with respect to vibration and possibly other disciplines is achieved. The proposed method is applied to an industry use case, where the rubber mount and geometrical layout of a vibratory rammer are modified to improve its dynamic and static performance. Both the system model and component model are validated by experiments. The vibration of a reference design is reduced by 48%. Full article
(This article belongs to the Section Machine Design and Theory)
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17 pages, 10395 KiB  
Article
Improvement of Crashworthiness Indicators with a New Idea in the Design of the Multi-Cell Hexagonal Tube under Dynamic Axial Load
by Reza Sistani, Mahmoud Mousavi Mashhadi and Younes Mohammadi
Machines 2023, 11(6), 641; https://doi.org/10.3390/machines11060641 - 11 Jun 2023
Viewed by 891
Abstract
Multi-cell hexagonal tubes have been applied in a wide range of industries. The present study investigates strengthening a single regular hexagonal tube under a dynamic axial load with three different geometrical shapes. The results are then compared with crashworthiness indicators from the finite [...] Read more.
Multi-cell hexagonal tubes have been applied in a wide range of industries. The present study investigates strengthening a single regular hexagonal tube under a dynamic axial load with three different geometrical shapes. The results are then compared with crashworthiness indicators from the finite element code LS-DYNA using the simple additive weighting method, and the appropriate section of a multi-cell hexagonal tube under dynamic axial load is selected. An idea is further presented by assuming the thicknesses variable for certain parts of the selected section to improve crashworthiness criteria. Combinations with different variable thicknesses in defined thickness intervals are made into a lattice. Numerical tests are performed based on the lattice nodes using LS-DYNA. The regression models for crashworthiness indicators are created using the Minitab software and optimized to find optimum combinations of thicknesses. The optimization results are tested again by LS-DYNA, and the appropriate answers are determined. The comparison of the results of this method with those of optimization with constant thicknesses demonstrates improvement in the crashworthiness indicators. Full article
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21 pages, 5698 KiB  
Article
Optimal Coordinated Control of Active Front Steering and Direct Yaw Moment for Distributed Drive Electric Bus
by Jiming Lin, Teng Zou, Liang Su, Feng Zhang and Yong Zhang
Machines 2023, 11(6), 640; https://doi.org/10.3390/machines11060640 - 11 Jun 2023
Cited by 1 | Viewed by 922
Abstract
This paper suggests a hierarchical coordination control strategy to enhance the stability of distributed drive electric bus. First, an observer based on sliding mode observer (SMO) and adaptive neural fuzzy inference system (ANFIS) was designed to estimate the vehicle state parameters. Then the [...] Read more.
This paper suggests a hierarchical coordination control strategy to enhance the stability of distributed drive electric bus. First, an observer based on sliding mode observer (SMO) and adaptive neural fuzzy inference system (ANFIS) was designed to estimate the vehicle state parameters. Then the upper layer of the strategy primarily focuses on coordinating active front steering (AFS) and direct yaw moment control (DYC). The phase plane method is utilized in this layer to provide an assessment basis for the switching control safety of AFS and DYC. The lower layer of the strategy designs an integral terminal sliding mode controller (ITSMC) and a non-singular fast terminal sliding mode controller (NFTSMC) to obtain the optimal additional front wheel steering angle to improve handling performance. A fuzzy sliding mode controller (FSMC) is also proposed to obtain additional yaw moment to ameliorate yaw stability. Finally, the strategy proposed in this paper is subjected to simulation testing and compared with the performance of AFS and DYC systems. The proposed strategy is also evaluated for tracking errors in sideslip angle and yaw rate under two conditions. The results demonstrate that the proposed strategy can effectively adapt to various extreme environments and improve the maneuvering and yaw stability of the bus. Full article
(This article belongs to the Special Issue Advanced Modeling, Analysis and Control for Electrified Vehicles)
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19 pages, 5459 KiB  
Article
Vibration Resonance Spectrometry (VRS) for the Advanced Streaming Detection of Rotor Unbalance
by Matthew T. Gerdes, Yawen Wang, Xinqi Wei, Guang C. Wang, Ruixian Liu and Kenny C. Gross
Machines 2023, 11(6), 639; https://doi.org/10.3390/machines11060639 - 09 Jun 2023
Viewed by 1067
Abstract
Determination of the diagnosis thresholds is crucial for the fault diagnosis of industry assets. Rotor machines under different working conditions are especially challenging because of the dynamic torque and speed. In this paper, an advanced machine learning based signal-processing innovation termed the multivariate [...] Read more.
Determination of the diagnosis thresholds is crucial for the fault diagnosis of industry assets. Rotor machines under different working conditions are especially challenging because of the dynamic torque and speed. In this paper, an advanced machine learning based signal-processing innovation termed the multivariate state estimation technique is proposed to improve the accuracy of the diagnosis thresholds. A novel preprocessing technique called vibration resonance spectrometry is also applied to achieve a low computation cost capability for real-time condition monitoring. The monitoring system that utilizes the above methods is then applied for prognostics of a fan model as an example. Different levels of radial unbalance were added on the fan and tested, and then compared with the health state. The results show that the proposed methodology can detect the unbalance with a good accuracy and low computation cost. The proposed methodology can be applied for complex engineering assets for better predictive monitoring that could be processed with on-premise edge devices, or eventually a cloud platform due to its capacity for loss-less dimension reduction. Full article
(This article belongs to the Special Issue Noise and Vibration Control in Dynamic Systems)
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