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Machines, Volume 9, Issue 11 (November 2021) – 57 articles

Cover Story (view full-size image): A beam-based tool edge profiler, consisting of a probe unit and a multi-axis precision positioning system, can realize the on-machine measurement of a tool cutting edge. By using the probe unit as a touch-trigger probe, edge profile measurement with a low contact force can be realized. Meanwhile, the mechanical characteristics of the probe consisting of a stylus and a beam could affect measurement performance. In this paper, the slopes and the top flat surface of a tool cutting edge have been measured using two types of probes: a double-sided beam probe and a cantilever beam probe. The measurement performances of the two types of probes have been compared through experiments, as well as theoretical investigation through measurement uncertainty analysis.View this paper
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17 pages, 2750 KiB  
Article
Adaptive Admittance Control Scheme with Virtual Reality Interaction for Robot-Assisted Lower Limb Strength Training
by Musong Lin, Hongbo Wang, Jianye Niu, Yu Tian, Xincheng Wang, Guowei Liu and Li Sun
Machines 2021, 9(11), 301; https://doi.org/10.3390/machines9110301 - 22 Nov 2021
Cited by 5 | Viewed by 2124
Abstract
Muscle weakness is the primary impairment causing mobility difficulty among stroke survivors. Millions of people are unable to live normally because of mobility difficulty every year. Strength training is an effective method to improve lower extremity ability but is limited by the shortage [...] Read more.
Muscle weakness is the primary impairment causing mobility difficulty among stroke survivors. Millions of people are unable to live normally because of mobility difficulty every year. Strength training is an effective method to improve lower extremity ability but is limited by the shortage of medical staff. Thus, this paper proposes a robot-assisted active training (RAAT) by an adaptive admittance control scheme with virtual reality interaction (AACVRI). AACVRI consists of a stiffness variable admittance controller, an adaptive controller, and virtual reality (VR) interactions. In order to provide human-robot reality interactions corresponding to virtual scenes, an admittance control law with variable stiffness term was developed to define the mechanics property of the end effector. The adaptive controller improves tracking performances by compensating interaction forces and dynamics model deviations. A virtual training environment including action following, event feedback, and competition mechanism is utilized for improving boring training experience and engaging users to maintain active state in cycling training. To verify controller performances and the feasibility of RAAT, experiments were conducted with eight subjects. Admittance control provides desired variable interactions along the trajectory. The robot responds to different virtual events by changing admittance parameters according to trigger feedbacks. Adaptive control ensures tracking errors at a low level. Subjects were maintained in active state during this strength training. Their physiological signals significantly increased, and interaction forces were at a high level. RAAT is a feasible approach for lower limb strength training, and users can independently complete high-quality active strength training under RAAT. Full article
(This article belongs to the Special Issue Learning Control Design and Analysis for Human-Robot Interaction)
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16 pages, 3937 KiB  
Article
Designing and Developing a Smart Yogurt Filling Machine in the Industry 4.0 Era
by Bashir Salah, Ali M. Alsamhan, Sajjad Khan and Mohammed Ruzayqat
Machines 2021, 9(11), 300; https://doi.org/10.3390/machines9110300 - 22 Nov 2021
Cited by 8 | Viewed by 3866
Abstract
Industry 4.0 allows for greater flexibility in production processes so that products can be customized (i.e., mass customization). Innovative production techniques in an industrial liquid/yogurt filling machine (YFM) improved efficiency in the beverage industry. In this study, we have introduced the second phase [...] Read more.
Industry 4.0 allows for greater flexibility in production processes so that products can be customized (i.e., mass customization). Innovative production techniques in an industrial liquid/yogurt filling machine (YFM) improved efficiency in the beverage industry. In this study, we have introduced the second phase designed control architecture of our YFM based on the concepts of industry 4.0 incorporating an NFC platform for improving customer satisfaction. Especially during this pandemic period, wireless technologies have been ubiquitous and pervasive for customized products. The basic components of the YFM have been described. High-level control architecture programmed fully automated filling operations, and the design stage of the development of a PFC-based controller for the YFM is elaborated. For the evaluation of the proposed control system, the operations of the electric/pneumatic input devices and actuators were simulated on FluidSIM-MecLab. The results of the simulation verify the design logic of the PFC-based controller. Comparisons were made between different production types using the developing YFM. A complex learning environment replicating a real production system to understand, learn, and apply modern manufacturing approaches has been developed. Through the creation of this YFM, the academic environment and industrial applications are combined. Consequently, the problem verification is becoming more realistic and more efficient than online (trial and error) automation programming. Full article
(This article belongs to the Special Issue Intelligent Factory 4.0: Advanced Production and Automation Systems)
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13 pages, 3161 KiB  
Article
Infrared Laser Speckle Projection-Based Multi-Sensor Collaborative Human Body Automatic Scanning System
by Xiao Yang, Juntong Xi, Jingyu Liu and Xiaobo Chen
Machines 2021, 9(11), 299; https://doi.org/10.3390/machines9110299 - 22 Nov 2021
Viewed by 1973
Abstract
Human body scanning is an important means to build a digital 3D model of the human body, which is the basis for intelligent clothing production, human obesity analysis, and medical plastic surgery applications, etc. Comparing to commonly used optical scanning technologies such as [...] Read more.
Human body scanning is an important means to build a digital 3D model of the human body, which is the basis for intelligent clothing production, human obesity analysis, and medical plastic surgery applications, etc. Comparing to commonly used optical scanning technologies such as laser scanning and fringe structured light, infrared laser speckle projection-based 3D scanning technology has the advantages of single-shot, simple control, and avoiding light stimulation to human eyes. In this paper, a multi-sensor collaborative digital human body scanning system based on near-infrared laser speckle projection is proposed, which occupies less than 2 m2 and has a scanning period of about 60 s. Additionally, the system calibration method and control scheme are proposed for the scanning system, and the serial-parallel computing strategy is developed based on the unified computing equipment architecture (CUDA), so as to realize the rapid calculation and automatic registration of local point cloud data. Finally, the effectiveness and time efficiency of the system are evaluated through anthropometric experiments. Full article
(This article belongs to the Special Issue Industrial Informatics and Digital Twin)
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17 pages, 2095 KiB  
Article
Assessment of Dynamic Bayesian Models for Gas Turbine Diagnostics, Part 1: Prior Probability Analysis
by Valentina Zaccaria, Amare Desalegn Fentaye and Konstantinos Kyprianidis
Machines 2021, 9(11), 298; https://doi.org/10.3390/machines9110298 - 21 Nov 2021
Cited by 5 | Viewed by 1473
Abstract
The reliability and cost-effectiveness of energy conversion in gas turbine systems are strongly dependent on an accurate diagnosis of possible process and sensor anomalies. Because data collected from a gas turbine system for diagnosis are inherently uncertain due to measurement noise and errors, [...] Read more.
The reliability and cost-effectiveness of energy conversion in gas turbine systems are strongly dependent on an accurate diagnosis of possible process and sensor anomalies. Because data collected from a gas turbine system for diagnosis are inherently uncertain due to measurement noise and errors, probabilistic methods offer a promising tool for this problem. In particular, dynamic Bayesian networks present numerous advantages. In this work, two Bayesian networks were developed for compressor fouling and turbine erosion diagnostics. Different prior probability distributions were compared to determine the benefits of a dynamic, first-order hierarchical Markov model over a static prior probability and one dependent only on time. The influence of data uncertainty and scatter was analyzed by testing the diagnostics models on simulated fleet data. It was shown that the condition-based hierarchical model resulted in the best accuracy, and the benefit was more significant for data with higher overlap between states (i.e., for compressor fouling). The improvement with the proposed dynamic Bayesian network was 8 percentage points (in classification accuracy) for compressor fouling and 5 points for turbine erosion compared with the static network. Full article
(This article belongs to the Special Issue Diagnostics and Optimization of Gas Turbine)
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20 pages, 7660 KiB  
Article
Full-Scale Train-to-Train Impact Test and Multi-Body Dynamic Simulation Analysis
by Hui Zhao, Ping Xu, Benhuai Li, Shuguang Yao, Chengxing Yang, Wei Guo and Xianliang Xiao
Machines 2021, 9(11), 297; https://doi.org/10.3390/machines9110297 - 19 Nov 2021
Cited by 11 | Viewed by 2771
Abstract
When a train crashes with another train at a high speed, it will lead to significant financial losses and societal costs. Carrying out a train-to-train crash test is of great significance to reproducing the collision response and assessing the safety performance of trains. [...] Read more.
When a train crashes with another train at a high speed, it will lead to significant financial losses and societal costs. Carrying out a train-to-train crash test is of great significance to reproducing the collision response and assessing the safety performance of trains. To ensure the testability and safety of the train collision test, it is necessary to analyze and predict the dynamic behavior of the train in the whole test process before the test. This paper presents a study of the dynamic response of the train in each test stage during the train-to-train crash test under different conditions. In this study, a 1D/3D co-simulation dynamics model of the train under various load conditions of driving, collision and braking has been established based on the MotionView dynamic simulation software. The accuracy of the numerical model is verified by comparing with a five-vehicle formations train-to-train crash test data. Sensitivities of several key influencing parameters, such as the train formation, impact velocity and the vehicle mass, are reported in detail as well. The results show that the increase in the impact velocity has an increasing effect on the movement displacement of the vehicle in each process. However, increasing the vehicle mass and train formation has almost no effect on the running displacement of the braking process of the traction train. By sorting the variables in descending order of sensitivity, it can be obtained that impact speed > train formation > vehicle mass. The polynomial response surface method (PRSM) is used to construct the fitting relationship between the parameters and the responses. Full article
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16 pages, 6161 KiB  
Article
Straw/Spring Teeth Interaction Analysis of Baler Picker in Smart Agriculture via an ADAMS-DEM Coupled Simulation Method
by Qingqing Wang, Ziwen Bai, Zhiqiang Li, Dongbo Xie, Liqing Chen and Hai Wang
Machines 2021, 9(11), 296; https://doi.org/10.3390/machines9110296 - 19 Nov 2021
Cited by 6 | Viewed by 2213
Abstract
In this paper, a new coupling simulation method is proposed for baler picker using automatic dynamic analysis of mechanical systems (ADAMS) and discrete element method (DEM). Field tests are carried out to verify the accuracy of the simulation model. By using the coupling [...] Read more.
In this paper, a new coupling simulation method is proposed for baler picker using automatic dynamic analysis of mechanical systems (ADAMS) and discrete element method (DEM). Field tests are carried out to verify the accuracy of the simulation model. By using the coupling method, not only was it obtained that the forward velocity (FV) and the ground clearance of spring teeth (GCST) are positively correlated with the pick-up loss rate (PLR), but also that the blockage of the picker mainly occurs in the straw pushing area, and an optimization plan is proposed. Through the analysis of the acting force (AF) between the roller and the track groove, we speculate that the structure of the track groove in a certain area is defective. The coupling method and optimization scheme proposed in this paper can provide a reference for the optimal design of the picker. Full article
(This article belongs to the Section Machine Design and Theory)
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23 pages, 8937 KiB  
Article
An Approach to the Study of a 19th-Century Sugarcane Mill and Steam Engine through CAD Techniques and Mechanical Engineering
by José Ignacio Rojas-Sola, Gloria del Río-Cidoncha, Rafael Ortíz-Marín and Justino Trenas-Arbizu
Machines 2021, 9(11), 295; https://doi.org/10.3390/machines9110295 - 19 Nov 2021
Cited by 2 | Viewed by 2510
Abstract
This article shows an approach to the three-dimensional modelling of a sugarcane mill and its associated steam engine, designed by the Robey and Co. engineering company in 1869. In order to obtain the 3D CAD model of said invention, CATIA V5 R20 software [...] Read more.
This article shows an approach to the three-dimensional modelling of a sugarcane mill and its associated steam engine, designed by the Robey and Co. engineering company in 1869. In order to obtain the 3D CAD model of said invention, CATIA V5 R20 software has been employed. Various sources of starting material, from the basis of this research and found in the process of searching for relevant information, provide information on the main elements, operating conditions, and mechanism of the machine. Thanks to the three-dimensional geometric modelling carried out, it has been possible to explain, in detail, both its operation and the final assembly of the invention through the assemblies of its different subsets, thereby obtaining a virtual recreation that shows its operation. Likewise, a study has been carried out, from a mechanical engineering viewpoint, of the gear train that transmitted the movement, in order to ascertain the compression force exerted on the sugar cane. This research, related to industrial archaeology, therefore, enables the reader to understand a machine that constituted a milestone in the sugarcane industry, while paying tribute to the English engineer, Robert Robey. Full article
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14 pages, 4595 KiB  
Article
Theoretical and Experimental Research on Switching Optimization of No. 9 Single Turnout with 60-kg/m Rails
by Pu Wang, Shuguo Wang, Zhenhua Zhao and Daolin Si
Machines 2021, 9(11), 294; https://doi.org/10.3390/machines9110294 - 19 Nov 2021
Viewed by 1507
Abstract
Based on the necessity of optimizing the structure of No. 9 single turnouts of 60-kg/m rails, we addressed the issues associated with existing turnout switching design methods. Based on finite element analysis, we established a refined calculation model for turnout switching. The model [...] Read more.
Based on the necessity of optimizing the structure of No. 9 single turnouts of 60-kg/m rails, we addressed the issues associated with existing turnout switching design methods. Based on finite element analysis, we established a refined calculation model for turnout switching. The model can determine the plane alignment of a switch rail separated from the stock rail based on the actual force acting upon the switch rail. The obtained plane alignment is consistent with the actual situation and is thus reliable. Based on the established turnout switching model, the minimum flangeway width and dynamics between the strokes of the first and second traction points under different conditions were analyzed by numerical simulations. Accordingly, we propose an optimized scheme that takes 160 mm and 85 mm as the stroke value for the first and second traction points, respectively. The scheme helps to meet the requirements for minimum flangeway width while making the deformation of the switch rail more even and therefore minimizing the traction power. Based on the proposed design, trial production and laying of the new No. 9 single turnout with a 60-kg/m rail was conducted, and a switching test was performed. The switching forces at the first and second traction points of the new No. 9 turnout were approximately 1200 and 2000 N, respectively, which were higher than those of existing No. 9 turnouts with 60-kg/m steel rails. Besides, the minimum flangeway width satisfies the requirement for safe vehicle passage with a safety margin of 3–5 mm. The test results proved the effectiveness of the proposed turnout switching design method and parameter optimization scheme. Full article
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12 pages, 5641 KiB  
Article
Experimental Research and Numerical Analysis of Pressure Fluctuation Characteristics of Rim Driven Propulsion Pump Outlet
by Zhipeng Zhu and Houlin Liu
Machines 2021, 9(11), 293; https://doi.org/10.3390/machines9110293 - 18 Nov 2021
Cited by 2 | Viewed by 1691
Abstract
The pressure fluctuation characteristics of a rim driven propulsion pump are studied by an experimental method firstly, and then its unsteady inner flow is studied by numerical simulation to reveal the generating mechanism of the pressure fluctuation. In the experiment, a monitoring point [...] Read more.
The pressure fluctuation characteristics of a rim driven propulsion pump are studied by an experimental method firstly, and then its unsteady inner flow is studied by numerical simulation to reveal the generating mechanism of the pressure fluctuation. In the experiment, a monitoring point was set in a downstream region with a distance of 1D (D, Diameter of impeller) to the impeller. The monitoring point’s dominant frequencies within a low frequency band are 1APF (APF, Axial Passing Frequency) and 2APF. In the numerical simulation, the main fluctuation near the impeller region appears at 1BPF (BPF, Blade Passing Frequency) and as the monitoring point moves downstream, the amplitude becomes smaller. The 1BPF fluctuation nearly disappears when the distance exceeds 1D, and the main frequency moves to 1APF and 2APF, which is in good agreement with the experimental results in the low frequency band. The transient velocity, pressure and vorticity distribution were studied to reveal the causes of 1BPF, 1APF and 2APF fluctuation. The main cause of 1BPF is the jet from the tail of the blade and the main cause of 2APF is the movement of a large-scale double vortex structure on both sides of the low-pressure zone. The movement of the vortex group near the wall may be the main cause that induces the 1APF fluctuation. Full article
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22 pages, 2510 KiB  
Article
New FMEA Risks Ranking Approach Utilizing Four Fuzzy Logic Systems
by Jelena Ivančan and Dragutin Lisjak
Machines 2021, 9(11), 292; https://doi.org/10.3390/machines9110292 - 16 Nov 2021
Cited by 20 | Viewed by 3005
Abstract
Process equipment and plant maintenance problems are complex in the oil refinery business, since effective maintenance needs to ensure the reliability and availability of the plant. Failure Mode and Effects Analysis (FMEA) is a risk assessment tool that aims to determine possible failure [...] Read more.
Process equipment and plant maintenance problems are complex in the oil refinery business, since effective maintenance needs to ensure the reliability and availability of the plant. Failure Mode and Effects Analysis (FMEA) is a risk assessment tool that aims to determine possible failure modes, and to reduce the ratio of unknown failure modes, by identifying business-critical systems and the risks of their failures. For the identified failure modes, FMEA determines risk mitigation action(s). The goal is to prevent failure and keep assets and plants running at peak performance by providing fully integrated operations, maintenance, turnarounds, modifications, and asset integrity solutions, during all phases of the asset life cycle. This research was based on FMEA use/application in refineries’ units, and proposes the new fuzzy FMEA risk quantification approach method: “four fuzzy logic system”. The model included a pre-assessment, by sets of fuzzy logic systems, that examined the input parameters that affected the variables of severity, occurrence, and detectability. The proposed model prioritized risks better and addressed the drawbacks of the conventional FMEA method. Full article
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15 pages, 4982 KiB  
Article
Optimization of Honing Surface Roughness of Carburized Holes Based on GRA-RSM
by Tao Tang, Chi Liu and Rong Wang
Machines 2021, 9(11), 291; https://doi.org/10.3390/machines9110291 - 16 Nov 2021
Cited by 4 | Viewed by 1685
Abstract
The carburized holes processed by ordinary internal grinding are prone to burn, crack, and low efficiency. Honing has a superior machining efficiency and cooling effect compared to traditional internal grinding. In this paper, we innovatively apply honing to carburizing hole grinding and propose [...] Read more.
The carburized holes processed by ordinary internal grinding are prone to burn, crack, and low efficiency. Honing has a superior machining efficiency and cooling effect compared to traditional internal grinding. In this paper, we innovatively apply honing to carburizing hole grinding and propose an effective optimization scheme to enhance the surface finish of carburized holes. We set up an experimental system to explore the influence law of honing head rotation speed, axial reciprocating speed, grain size, and single grinding depth on surface roughness. Based on the grey correlation and response surface method, we propose a method to optimize the honing parameters of carburized holes and establish a prediction model, which has an R2 value of 0.9887, indicating that the model fits well. We verify the validity of the model by the root mean square error of 0.012 between the measured and calculated values. Based on the model, the optimal parameters of roughness (Ra) is obtained and verified by experiments. Compared with the original honing parameters, the surface roughness quality is improved by 25.8%. It shows that the optimized honing process based on the GRA-RSM method improves the surface quality of carburized holes significantly. Full article
(This article belongs to the Section Material Processing Technology)
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13 pages, 2545 KiB  
Article
A Graph-Based Optimal On-Ramp Merging of Connected Vehicles on the Highway
by Yanjun Shi, Zhiheng Yuan, Hao Yu, Yijia Guo and Yuhan Qi
Machines 2021, 9(11), 290; https://doi.org/10.3390/machines9110290 - 16 Nov 2021
Cited by 4 | Viewed by 2127
Abstract
Connected and automated vehicles (CAVs) are a very promising alternative for reducing fuel consumption and improving traffic efficiency when vehicles merge at on-ramps. In this study, we propose a graph-based method to coordinate CAVs to merge at the highway ramp. First, the optimized [...] Read more.
Connected and automated vehicles (CAVs) are a very promising alternative for reducing fuel consumption and improving traffic efficiency when vehicles merge at on-ramps. In this study, we propose a graph-based method to coordinate CAVs to merge at the highway ramp. First, the optimized vehicles were divided into groups to pass the merging point. Then we built a directed graph model for each group of vehicles, where each path of the graph corresponds to one of all possible merging sequences. The improved shortest path algorithm is proposed to find the optimal merging sequence for minimizing total fuel consumption. The results of the simulation showed that the proposed graph-based method reduced fuel consumption and ensured high traffic efficiency; moreover, the vehicles can form a platoon after passing the merge point. Full article
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17 pages, 4935 KiB  
Article
Dynamic Modeling of a Front-Loading Type Washing Machine and Model Reliability Investigation
by Jungjoon Park, Sinwoo Jeong and Honghee Yoo
Machines 2021, 9(11), 289; https://doi.org/10.3390/machines9110289 - 15 Nov 2021
Cited by 2 | Viewed by 2546
Abstract
A linear dynamic model of a front-loading type washing machine was developed in this study. The machine was conceptualized with three moving rigid bodies, revolute joints, springs, and dampers along with prescribed rotational drum motion. Kane’s method was employed for deriving the equations [...] Read more.
A linear dynamic model of a front-loading type washing machine was developed in this study. The machine was conceptualized with three moving rigid bodies, revolute joints, springs, and dampers along with prescribed rotational drum motion. Kane’s method was employed for deriving the equations of motion of the idealized washing machine. Since the modal and transient characteristics can be conveniently investigated with a linear dynamic model, the linear model can be effectively used for the design of an FL type washing machine. Despite the convenience, however, the reliability of the linear dynamic model is often restricted to a certain range of system parameters. Parameters relevant to the reliability of the linear dynamic model were identified and the parameters’ ranges that could guarantee the reliability of the proposed linear dynamic model were numerically investigated in this study. Full article
(This article belongs to the Special Issue Dynamic Analysis of Multibody Mechanical Systems)
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15 pages, 6520 KiB  
Article
Experimental Investigation of Unsteady Pressure Pulsation in New Type Dishwasher Pump with Special Double-Tongue Volute
by Yilei Zhu, Jinfeng Zhang, Yalin Li, Ping Huang, Hui Xu and Feng Zheng
Machines 2021, 9(11), 288; https://doi.org/10.3390/machines9110288 - 14 Nov 2021
Cited by 3 | Viewed by 1629
Abstract
A pressure pulsation experiment of a dishwasher pump with a passive rotation double-tongue volute was carried out and compared with the pressure pulsation of a single-tongue volute and a static double-tongue volute. The pressure pulsation of the three volute models was compared and [...] Read more.
A pressure pulsation experiment of a dishwasher pump with a passive rotation double-tongue volute was carried out and compared with the pressure pulsation of a single-tongue volute and a static double-tongue volute. The pressure pulsation of the three volute models was compared and analyzed from two aspects of different impeller speeds and different monitoring points. The frequency domain and time–frequency domain of pressure pulsation were obtained by a Fourier transform and short-time Fourier transform, respectively. The results showed that the average pressure of each monitoring point on the rotating double-tongue volute was the smallest and that on the single-tongue volute was the largest. When the impeller rotates at 3000 rpm, there were eight peaks and valleys in the pressure pulsation time domain curve of the single-tongue volute, while the double-tongue volute was twice that of the single-tongue volute. Under different impeller speeds, the changing trends of pressure pulsation time and frequency domain curves of static and rotating double-tongue volutes at monitoring point p1 are basically the same. Therefore, a volute reference scheme with passive rotation speed is proposed in this study, which can effectively improve the flow pattern and reduce pressure inside the dishwasher pump, and also provide a new idea for rotor–rotor interference to guide the innovation of dishwashers. Full article
(This article belongs to the Special Issue Optimization and Flow Characteristics in Advanced Fluid Machinery)
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12 pages, 5238 KiB  
Communication
On the Asymptotic Behavior and Parameter Estimation of a Double-Sided LCC-Compensated Wireless Power Transfer System
by Feng-Rung Hu and Jia-Sheng Hu
Machines 2021, 9(11), 287; https://doi.org/10.3390/machines9110287 - 13 Nov 2021
Cited by 3 | Viewed by 1566
Abstract
This study investigates the statistic behavior and parameter estimation problems of a double-sided, LCC-compensated, wireless power transfer system. Based on the commonly used wireless charging circuit model, this study proposes a five-step parameter estimation method, which is applicable to automotive static wireless charging [...] Read more.
This study investigates the statistic behavior and parameter estimation problems of a double-sided, LCC-compensated, wireless power transfer system. Based on the commonly used wireless charging circuit model, this study proposes a five-step parameter estimation method, which is applicable to automotive static wireless charging systems. The eight parameters in the circuit model of this study are the most important key components of the wireless charging system. The study also found that, under certain conditions, the statistic mode of wireless charging systems has a specific distribution. However, the current status of these eight components for wireless charging of electric vehicles will have complex parameter drift problems. These drift problems will deteriorate the performance of the vehicle power systems. This study probes these factors and proposes some related mathematical theories. The noted factors can be applied to the analysis of the wireless charging system and provide alternative solutions to explain the deteriorations from coil misalignments. Both simulations and experiments are given to show the evaluated issues of the proposed study. Full article
(This article belongs to the Special Issue Design and Control of Electrical Machines)
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16 pages, 2775 KiB  
Article
Research on Thermal Error Modeling of Motorized Spindle Based on BP Neural Network Optimized by Beetle Antennae Search Algorithm
by Zhaolong Li, Bo Zhu, Ye Dai, Wenming Zhu, Qinghai Wang and Baodong Wang
Machines 2021, 9(11), 286; https://doi.org/10.3390/machines9110286 - 12 Nov 2021
Cited by 17 | Viewed by 2022
Abstract
High-speed motorized spindle heating will produce thermal error, which is an important factor affecting the machining accuracy of machine tools. The thermal error model of high-speed motorized spindles can compensate for thermal error and improve machining accuracy effectively. In order to confirm the [...] Read more.
High-speed motorized spindle heating will produce thermal error, which is an important factor affecting the machining accuracy of machine tools. The thermal error model of high-speed motorized spindles can compensate for thermal error and improve machining accuracy effectively. In order to confirm the high precision thermal error model, Beetle antennae search algorithm (BAS) is proposed to optimize the thermal error prediction model of motorized spindle based on BP neural network. Through the thermal characteristic experiment, the A02 motorized spindle is used as the research object to obtain the temperature and axial thermal drift data of the motorized spindle at different speeds. Using fuzzy clustering and grey relational analysis to screen temperature-sensitive points. Beetle antennae search algorithm (BAS) is used to optimize the weights and thresholds of the BP neural network. Finally, the BAS-BP thermal error prediction model is established. Compared with BP and GA-BP models, the results show that BAS-BP has higher prediction accuracy than BP and GA-BP models at different speeds. Therefore, the BAS-BP model is suitable for prediction and compensation of spindle thermal error. Full article
(This article belongs to the Special Issue Optimal Design of a High-Speed Motor)
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17 pages, 6403 KiB  
Article
Performance of Relative Clearance Ratio of Floating Ring Bearing for Turbocharger-Rotor System Stability
by Liqiang Peng, Huiping Zheng and Zhanqun Shi
Machines 2021, 9(11), 285; https://doi.org/10.3390/machines9110285 - 12 Nov 2021
Cited by 1 | Viewed by 1778
Abstract
The floating ring bearing (FRB) has been widely used in the field of high-speed rotating machinery such as turbochargers, aviation engines and so on, because of its simple structure, high efficiency and low power consumption. In order to obtain the best ratio between [...] Read more.
The floating ring bearing (FRB) has been widely used in the field of high-speed rotating machinery such as turbochargers, aviation engines and so on, because of its simple structure, high efficiency and low power consumption. In order to obtain the best ratio between inter-oil clearance and shaft radius of the floating ring bearing necessitates the design reference of dimensional parameters for the design of floating ring bearings. This study, based on the transfer-matrix method, developed the dynamic model of the floating ring bearing-rotor system, and, using the Runge–Kutta analysis method for floating ring bearings, the influence of oil film relative clearance ratio of floating rings on rotor system stability was analyzed and studied. The optimum clearance ratio between inner oil film and the shaft of floating ring bearings is λ = 0.01. This research can provide some theoretical support for the design of parameters and fault diagnosis of rotor floating ring bearing systems. Full article
(This article belongs to the Section Turbomachinery)
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16 pages, 7450 KiB  
Article
Obtainment of Residual Stress Distribution from Surface Deformation under Continuity Constraints for Thinned Silicon Wafers
by Haijun Liu, Tao Yang, Jiang Han, Xiaoqing Tian, Shan Chen and Lei Lu
Machines 2021, 9(11), 284; https://doi.org/10.3390/machines9110284 - 11 Nov 2021
Cited by 3 | Viewed by 2288
Abstract
Precision machining (e.g., fine grinding, polishing) induced residual stress is very small and often not constant across the wafer and it is difficult to be directly obtained by stress testing equipment or Stoney equation. The residual stress could be obtained theoretically based on [...] Read more.
Precision machining (e.g., fine grinding, polishing) induced residual stress is very small and often not constant across the wafer and it is difficult to be directly obtained by stress testing equipment or Stoney equation. The residual stress could be obtained theoretically based on the principle of superposition in which the entire wafer deformation is taken as the sum of all deformations induced by the residual stresses of different positions on the wafer surface. However, the solved residual stress is affected greatly by deformation measurement errors and fluctuates greatly across the wafer surface. To solve the problem, a regularization method with continuity constraints was proposed in this study. The mechanisms for the discontinuity of the residual stress distribution and the sensitivity of calculation results to the measurement errors were studied. The influences of the number of subareas of the silicon wafer were investigated and the continuity constraint term was constructed based on the positional relationship of different subareas. Stable and continuous residual stress distribution was successfully obtained after using the proposed regularization method. The method may also be applied to estimate the residual stress from surface deformation for thin substrate plates of other materials. Full article
(This article belongs to the Section Material Processing Technology)
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15 pages, 2985 KiB  
Article
Sliding Mode Control of Electro-Hydraulic Servo System Based on Optimization of Quantum Particle Swarm Algorithm
by Xinyu Zheng and Xiaoyu Su
Machines 2021, 9(11), 283; https://doi.org/10.3390/machines9110283 - 11 Nov 2021
Cited by 9 | Viewed by 1824
Abstract
This paper investigates a sliding mode controller based on quantum particle swarm optimization algorithm (QPSO) to solve the nonlinearity of electro-hydraulic servo systems, external disturbance problems, and jitter of sliding mode controller. The electro-hydraulic servo system state space equations are established, constructing the [...] Read more.
This paper investigates a sliding mode controller based on quantum particle swarm optimization algorithm (QPSO) to solve the nonlinearity of electro-hydraulic servo systems, external disturbance problems, and jitter of sliding mode controller. The electro-hydraulic servo system state space equations are established, constructing the sliding surface according to the tracking error and obtaining the output of the sliding mode controller. The ITAE metric is used as an adaptation function of the QPSO algorithm to evaluate the parameters in the sliding mode controller, which has good engineering utility and parameter selectivity. The QPSO algorithm is used to increase the randomicity of the search and to expand the search space, which can effectively prevent falling into a local optimum solution. Finally, a comparative simulation is presented to illustrate global search performance of QPSO algorithm and the effectiveness and applicability of the proposed control method. Full article
(This article belongs to the Special Issue Advanced Control of Industrial Electro-Hydraulic Systems)
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13 pages, 3820 KiB  
Article
Transfer of Process References between Machine Tools for Online Tool Condition Monitoring
by Berend Denkena, Benjamin Bergmann and Tobias H. Stiehl
Machines 2021, 9(11), 282; https://doi.org/10.3390/machines9110282 - 10 Nov 2021
Cited by 3 | Viewed by 2102
Abstract
Process and tool condition monitoring systems are a prerequisite for autonomous production. One approach to monitoring individual parts without complex cutting simulations is the transfer of knowledge among similar monitoring scenarios. This paper introduces a novel monitoring method which transfers monitoring limits for [...] Read more.
Process and tool condition monitoring systems are a prerequisite for autonomous production. One approach to monitoring individual parts without complex cutting simulations is the transfer of knowledge among similar monitoring scenarios. This paper introduces a novel monitoring method which transfers monitoring limits for process signals between different machine tools. The method calculates monitoring limits statistically from cutting processes carried out on one or more similar machines. The monitoring algorithm aims to detect general process anomalies online. Experiments comprise face-turning operations at five different lathes, four of which were of the same model. Results include the successful transfer of monitoring limits between machines of the same model for the detection of material anomalies. In comparison to an approach based on dynamic time warping (DTW) and density-based spatial clustering of applications with noise (DBSCAN), the new method showed fewer false alarms and higher detection rates. However, for the transfer between different models of machines, the successful application of the new method is limited. This is predominantly due to limitations of the employed process component isolation and differences between machine models in terms of signal properties as well as execution speed. Full article
(This article belongs to the Special Issue Robotic Machine Tools)
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13 pages, 4590 KiB  
Article
Contactless Fault Detection of a DC Motor Direction of Rotation Using Its Stray Magnetic Field
by Michal Matějásko, Martin Brablc, Martin Appel and Robert Grepl
Machines 2021, 9(11), 281; https://doi.org/10.3390/machines9110281 - 10 Nov 2021
Viewed by 1896
Abstract
In large-scale manufacturing and assembly applications, especially when trying to automate most steps, implementing quality control as early in the process as possible is the key to prevent expenses later. We deal mainly with the production of DC motor powered fuel pumps, which [...] Read more.
In large-scale manufacturing and assembly applications, especially when trying to automate most steps, implementing quality control as early in the process as possible is the key to prevent expenses later. We deal mainly with the production of DC motor powered fuel pumps, which are commonly used in the automotive industry. The goal of this paper is to present a newly developed technique for non-invasive fault detection of a DC motor’s direction of rotation using a stray magnetic field out of the motor chassis. The results presented in this paper show that it is possible to detect faults even on low-power motors while the algorithm is kept as simple as possible to allow for large-scale deployment on a production line. It also gives new insight into the behavior of the stray magnetic field of electric motors, which may benefit other applications and future research. Full article
(This article belongs to the Special Issue Structural Health Monitoring for Mechanical Systems)
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17 pages, 6493 KiB  
Article
A Particle Swarm Optimisation with Linearly Decreasing Weight for Real-Time Traffic Signal Control
by Yanjun Shi, Yuhan Qi, Lingling Lv and Donglin Liang
Machines 2021, 9(11), 280; https://doi.org/10.3390/machines9110280 - 10 Nov 2021
Cited by 4 | Viewed by 1894
Abstract
Nowadays, traffic congestion has become a significant challenge in urban areas and densely populated cities. Real-time traffic signal control is an effective method to reduce traffic jams. This paper proposes a particle swarm optimisation with linearly decreasing weight (LDW-PSO) to tackle the signal [...] Read more.
Nowadays, traffic congestion has become a significant challenge in urban areas and densely populated cities. Real-time traffic signal control is an effective method to reduce traffic jams. This paper proposes a particle swarm optimisation with linearly decreasing weight (LDW-PSO) to tackle the signal intersection control problem, where a finite-interval model and an objective function are built to minimise spoilage time. The performance was evaluated in real-time simulation imitating a crowded intersection in Dalian city (in China) via the SUMO traffic simulator. The simulation results showed that the LDW-PSO outperformed the classical algorithms in this research, where queue length can be reduced by up to 20.4% and average waiting time can be reduced by up to 17.9%. Full article
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16 pages, 18337 KiB  
Article
Flux Estimator for Salient Pole Synchronous Machines Driven by the Cycloconverter Based on Enhanced Current and Voltage Model of the Machine with Fuzzy Logic Transition
by Dominik Cikač, Nikola Turk, Neven Bulić and Stefano Barbanti
Machines 2021, 9(11), 279; https://doi.org/10.3390/machines9110279 - 09 Nov 2021
Cited by 1 | Viewed by 1904
Abstract
Flux estimation is a key feature of the field-oriented control for the electrically excited synchronous machine which enables the high-performance, high-dynamic drive behavior. In this work, an electrically excited synchronous machine flux estimator based on a current and voltage model is proposed. In [...] Read more.
Flux estimation is a key feature of the field-oriented control for the electrically excited synchronous machine which enables the high-performance, high-dynamic drive behavior. In this work, an electrically excited synchronous machine flux estimator based on a current and voltage model is proposed. In this case, the transition between the estimators is done with a fuzzy logic set of rules. The flux estimator based on the current model of the machine in this paper considers the saturation and cross-coupling effect in both axis and it is suitable for applications where a limited amount of the machine data is available. The flux estimator based on the voltage model is specially designed for the drives where high voltage and current ripple is present under normal operating conditions, e.g., like in cycloconverter applications. To exploit all the advantages of both models, a fuzzy logic transition is proposed based on multiple choices which manages the transition between the models based on a speed and torque reference. The proposed flux estimator is experimentally verified on a cycloconverter fed salient-pole electrically excited synchronous machine. The experimental results clearly show that the proposed flux estimator enables the accurate and stable operating conditions for different operating points of the cycloconverter-fed salient-pole electrically excited synchronous machine. Full article
(This article belongs to the Section Electrical Machines and Drives)
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30 pages, 5151 KiB  
Article
Multi-Domain Informative Coverage Path Planning for a Hybrid Aerial Underwater Vehicle in Dynamic Environments
by Xueyao Liang, Chunhu Liu and Zheng Zeng
Machines 2021, 9(11), 278; https://doi.org/10.3390/machines9110278 - 08 Nov 2021
Cited by 5 | Viewed by 2273
Abstract
Hybrid aerial underwater vehicles (HAUV) are a new frontier for vehicles. They can operate both underwater and aerially, providing enormous potential for a wide range of scientific explorations. Informative path planning is essential to vehicle autonomy. However, covering an entire mission region is [...] Read more.
Hybrid aerial underwater vehicles (HAUV) are a new frontier for vehicles. They can operate both underwater and aerially, providing enormous potential for a wide range of scientific explorations. Informative path planning is essential to vehicle autonomy. However, covering an entire mission region is a challenge to HAUVs because of the possibility of a multidomain environment. This paper presents an informative trajectory planning framework for planning paths and generating trajectories for HAUVs performing multidomain missions in dynamic environments. We introduce the novel heuristic generalized extensive neighborhood search GLNS–k-means algorithm that uses k-means to cluster information into several sets; then through the heuristic GLNS algorithm, it searches the best path for visiting these points, subject to various constraints regarding path budgets and the motion capabilities of the HAUV. With this approach, the HAUV is capable of sampling and focusing on regions of interest. Our method provides a significantly more optimal trajectory (enabling collection of more information) than ant colony optimization (ACO) solutions. Moreover, we introduce an efficient online replanning scheme to adapt the trajectory according to the dynamic obstacles during the mission. The proposed replanning scheme based on KD tree enables significantly shorter computational times than the scapegoat tree methods. Full article
(This article belongs to the Special Issue Dynamics and Motion Control of Unmanned Aerial/Underwater Vehicles)
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16 pages, 2280 KiB  
Article
Research on the Electromagnetic Conversion Method of Stator Current for Local Fault Detection of a Planetary Gearbox
by Xiangyang Xu, Guanrui Liu and Xihui Liang
Machines 2021, 9(11), 277; https://doi.org/10.3390/machines9110277 - 08 Nov 2021
Cited by 1 | Viewed by 1776
Abstract
Motor current signature analysis (MCSA) is a useful technique for planetary gear fault detection. Motor current signals have easier accessibility and are free from time-varying transfer path effects. If the fault symptoms in current signals are well understood, it will be more beneficial [...] Read more.
Motor current signature analysis (MCSA) is a useful technique for planetary gear fault detection. Motor current signals have easier accessibility and are free from time-varying transfer path effects. If the fault symptoms in current signals are well understood, it will be more beneficial to develop effective current signal processing methods. Some researchers have developed mathematical models to study the characteristics of current signals. However, no one has considered the coupling of rotor eccentricity and gear failures, resulting in an inaccurate analysis of the current signals. This study considers the sun gear failure of a planetary gearbox and the eccentricity of the motor rotor. An improved induction motor model is proposed based on the magnetomotive force (MMF) to simulate the stator current. By analyzing the current, the modulation relationships of gearbox meshing frequency, fault frequency, power supply frequency, and gear rotating frequency are obtained. The proposed model is validated to some extent using experimental data. Full article
(This article belongs to the Special Issue Advances in Bearing Modeling, Fault Diagnosis, RUL Prediction)
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37 pages, 17372 KiB  
Article
Modeling the Dynamics of a Gyroscopic Rigid Rotor with Linear and Nonlinear Damping and Nonlinear Stiffness of the Elastic Support
by Zharilkassin Iskakov, Kuatbay Bissembayev, Nutpulla Jamalov and Azizbek Abduraimov
Machines 2021, 9(11), 276; https://doi.org/10.3390/machines9110276 - 08 Nov 2021
Cited by 4 | Viewed by 2230
Abstract
This study analytically and numerically modeled the dynamics of a gyroscopic rigid rotor with linear and nonlinear cubic damping and nonlinear cubic stiffness of an elastic support. It has been shown that (i) joint linear and nonlinear cubic damping significantly suppresses the vibration [...] Read more.
This study analytically and numerically modeled the dynamics of a gyroscopic rigid rotor with linear and nonlinear cubic damping and nonlinear cubic stiffness of an elastic support. It has been shown that (i) joint linear and nonlinear cubic damping significantly suppresses the vibration amplitude (including the maximum) in the resonant velocity region and beyond it, and (ii) joint linear and nonlinear cubic damping more effectively affects the boundaries of the bistability region by its narrowing than linear damping. A methodology is proposed for determining and identifying the coefficients of nonlinear stiffness, linear damping, and nonlinear cubic damping of the support material, where jump-like effects are eliminated. Damping also affects the stability of motion; if linear damping shifts the left boundary of the instability region towards large amplitudes and speeds of rotation of the shaft, then nonlinear cubic damping can completely eliminate it. The varying amplitude (VAM) method is used to determine the nature of the system response, supplemented with the concept of “slow” time, which allows us to investigate and analyze the effect of nonlinear cubic damping and nonlinear rigidity of cubic order on the frequency response at a nonstationary resonant transition. Full article
(This article belongs to the Special Issue Kinematics and Dynamics of Mechanisms and Machines)
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27 pages, 19993 KiB  
Article
Multi-Frequency Weak Signal Decomposition and Reconstruction of Rolling Bearing Based on Adaptive Cascaded Stochastic Resonance
by Di Xu, Jianghua Ge, Yaping Wang and Junpeng Shao
Machines 2021, 9(11), 275; https://doi.org/10.3390/machines9110275 - 08 Nov 2021
Cited by 6 | Viewed by 1748
Abstract
In engineering practice, the bearing fault signal is composed of a series of complex multi-component signals containing multiple fault characteristics information. In the early stage of fault sprouting and evolution, the fault features are easily disturbed by noise and irrelevant signals, eliminating the [...] Read more.
In engineering practice, the bearing fault signal is composed of a series of complex multi-component signals containing multiple fault characteristics information. In the early stage of fault sprouting and evolution, the fault features are easily disturbed by noise and irrelevant signals, eliminating the fault signals in the strong background noise. To overcome the influence of noise on the signal, this study proposes multi-frequency weak signal decomposition and reconstruction of rolling bearing based on adaptive cascaded stochastic resonance. First, the original signal is passed through the Hilbert transform to obtain the envelope signal. The envelope signal is high-pass filtered to eliminate the interference of low-frequency components on the response of the stochastic resonance system. Secondly, cascaded stochastic resonance system parameters are adaptively optimized by the quantum particle swarm algorithm (QPSO). The high-pass filtered signal input to the adaptive cascaded stochastic resonance system (ACSRS) can further enhance the weak fault characteristics, allowing the gradual transfer of high-frequency noise energy to the low-frequency fault characteristic components. Finally, the signal is decomposed using the variational mode decomposition (VMD) method to jointly determine the location of the fault characteristic frequencies in the intrinsic mode functions (IMF) component by the energy loss coefficient and correlation coefficient to achieve the reconstruction of multi-frequency weak signals. Through simulation and experimental validation, the effectiveness and superiority of the method for multi-frequency weak signal detection in bearings are verified. The results show that the method not only achieves the adaptive optimization of the stochastic resonance system parameters gradually removing the high-frequency noise in the signal and improving the energy of the low-frequency signal but also reduces the number of decomposition layers of the VMD, enhances the fault characteristic information in the weak signal, and effectively identifies the early weak fault characteristics of rolling bearings. Full article
(This article belongs to the Section Machines Testing and Maintenance)
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18 pages, 5963 KiB  
Article
Application of a New Model Reference Adaptive Control Based on PID Control in CNC Machine Tools
by Hongdong Gai, Xuewei Li, Fangrui Jiao, Xiang Cheng, Xianhai Yang and Guangming Zheng
Machines 2021, 9(11), 274; https://doi.org/10.3390/machines9110274 - 08 Nov 2021
Cited by 10 | Viewed by 2410
Abstract
To improve the control performance of the CNC machine tool feed servo system with nonlinear disturbances, a model reference adaptive control (MRAC) based on PID control is proposed. The method is based on the traditional three-loop control, the output signal of the speed [...] Read more.
To improve the control performance of the CNC machine tool feed servo system with nonlinear disturbances, a model reference adaptive control (MRAC) based on PID control is proposed. The method is based on the traditional three-loop control, the output signal of the speed loop controller is used as the input signal of the model reference adaptive controller, and the adaptive law is derived on the basis of Lyapunov stability theory. To verify the effectiveness, this paper analyzed the method through simulation and experiment. Results showed that the following error caused by nonlinear friction was significantly reduced when the speed was reversed, and the influence of noise and mechanical resonance was effectively suppressed. The proposed control method in this paper improves the motion-control accuracy and anti-interference ability of the control system. Full article
(This article belongs to the Section Automation and Control Systems)
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31 pages, 19417 KiB  
Article
Experimental Characterization of Large Turbomachinery Tilting Pad Journal Bearings
by Enrico Ciulli, Riccardo Ferraro, Paola Forte, Alice Innocenti and Matteo Nuti
Machines 2021, 9(11), 273; https://doi.org/10.3390/machines9110273 - 07 Nov 2021
Cited by 4 | Viewed by 2078
Abstract
The paper deals with the experimental characterization of different 280 mm diameter tilting pad journal bearings for turbomachines using a dedicated test rig. The test articles were a 5-pad Direct Lube Rocker Pivot bearing, a 5-pad Flooded Rocker Pivot bearing, and a 4-pad [...] Read more.
The paper deals with the experimental characterization of different 280 mm diameter tilting pad journal bearings for turbomachines using a dedicated test rig. The test articles were a 5-pad Direct Lube Rocker Pivot bearing, a 5-pad Flooded Rocker Pivot bearing, and a 4-pad Flooded Ball and Socket Pivot bearing. The three bearings were tested in their specific design range of operating conditions. Their static and dynamic behavior was investigated as a function of different operating parameters. In particular, the assumed journal center eccentricity and pads temperature were measured, and the power loss determined as a function of angular speed for different static loads. Dynamic stiffness and damping coefficients were determined as a function of excitation frequency for different speeds and loads. The experimental results were compared showing the influence of the operating parameters, configuration, and oil supply. Full article
(This article belongs to the Special Issue Tilting Pad Journal Bearings: State of the Art)
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15 pages, 985 KiB  
Article
Disturbance Detection of a Power Transmission System Based on the Enhanced Canonical Variate Analysis Method
by Shubin Wang, Yukun Tian, Xiaogang Deng, Qianlei Cao, Lei Wang and Pengxiang Sun
Machines 2021, 9(11), 272; https://doi.org/10.3390/machines9110272 - 06 Nov 2021
Cited by 4 | Viewed by 1467
Abstract
Aiming at the characteristics of dynamic correlation, periodic oscillation, and weak disturbance symptom of power transmission system data, this paper proposes an enhanced canonical variate analysis (CVA) method, called SLCVAkNN, for monitoring the disturbances of power transmission systems. In the proposed [...] Read more.
Aiming at the characteristics of dynamic correlation, periodic oscillation, and weak disturbance symptom of power transmission system data, this paper proposes an enhanced canonical variate analysis (CVA) method, called SLCVAkNN, for monitoring the disturbances of power transmission systems. In the proposed method, CVA is first used to extract the dynamic features by analyzing the data correlation and establish a statistical model with two monitoring statistics T2 and Q. Then, in order to handling the periodic oscillation of power data, the two statistics are reconstructed in phase space, and the k-nearest neighbor (kNN) technique is applied to design the statistics nearest neighbor distance DT2 and DQ as the enhanced monitoring indices. Further considering the detection difficulty of weak disturbances with the insignificant symptoms, statistical local analysis (SLA) is integrated to construct the primary and improved residual vectors of the CVA dynamic features, which are capable to prompt the disturbance detection sensitivity. The verification results on the real industrial data show that the SLCVAkNN method can detect the occurrence of power system disturbance more effectively than the traditional data-driven monitoring methods. Full article
(This article belongs to the Special Issue Deep Learning-Based Machinery Fault Diagnostics)
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