In this paper, a nonlinear coupling model with hysteresis, dynamics, and creep is proposed to describe accurately the complex characteristics of piezoelectric-actuated positioning stage, where a classic Hammerstein model in series with a fractional-order model is given. The fractional-order model is presented to express the nonlinear creep characteristics. Firstly, the Hammerstein structure model is composed of two blocks, where the former block is the classical PI model to describe the static hysteresis effects, and the latter block is the second-order discrete transfer function model to characterize the dynamic characteristics. In addition, the parameters of the coupling model are identified. Secondly, based on the built model, the inverse of fractional-order model and the inverse of PI model are implemented as the feedforward compensations, and an adaptive control is designed to adjust the tracking performance of the whole system. Finally, the effectiveness of the proposed coupling model and controllers are verified by the piezoelectric-actuated positioning experiment stage. Experimental results show that the established coupling model can accurately characterize the hysteresis, dynamics, and creep properties of the stage. Also, the results show that the tracking error is less than 0.8% at low frequency and mixed frequency.
{"title":"Coupling Modeling and Adaptive Control for Piezoelectric-Actuated Positioning Stage","authors":"Liang Li, Shi-Xin Zhang, Sheng-Jun Wen","doi":"10.1155/2022/2534439","DOIUrl":"https://doi.org/10.1155/2022/2534439","url":null,"abstract":"In this paper, a nonlinear coupling model with hysteresis, dynamics, and creep is proposed to describe accurately the complex characteristics of piezoelectric-actuated positioning stage, where a classic Hammerstein model in series with a fractional-order model is given. The fractional-order model is presented to express the nonlinear creep characteristics. Firstly, the Hammerstein structure model is composed of two blocks, where the former block is the classical PI model to describe the static hysteresis effects, and the latter block is the second-order discrete transfer function model to characterize the dynamic characteristics. In addition, the parameters of the coupling model are identified. Secondly, based on the built model, the inverse of fractional-order model and the inverse of PI model are implemented as the feedforward compensations, and an adaptive control is designed to adjust the tracking performance of the whole system. Finally, the effectiveness of the proposed coupling model and controllers are verified by the piezoelectric-actuated positioning experiment stage. Experimental results show that the established coupling model can accurately characterize the hysteresis, dynamics, and creep properties of the stage. Also, the results show that the tracking error is less than 0.8% at low frequency and mixed frequency.","PeriodicalId":45541,"journal":{"name":"Modelling and Simulation in Engineering","volume":"49 1","pages":""},"PeriodicalIF":3.2,"publicationDate":"2022-09-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86834095","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Shoaib Sheikh, Dileep Kumar, Abdul Hakeem, Arsalan Muhammad Soomar
The fundamental and durable structures of induction motor, as well as their low manufacturing cost, make them popular components in a wide range of current applications. Providing a safety net for employees is a must-have for businesses. This project’s motivation for improvement is to provide industrial motors, lift motors, pumps, and so on with safety. An induction motor’s primary goal is to protect it from problems, such as single phasing and overheating, as well as other issues. Providing industrial motors, pumps, lift motors, and other similar devices with security is a major motivation behind the emergence of this issue. Any of the three phases missing or the motor temperature above the predetermined threshold causes the motor to stop instantly. Three one-stage transformers are connected to a three-phase power supply in the system. Power will be cut to the transformer circuit if any phase is available. Motors can be turned off by relays sending a signal to the four-pole contactor. As a result, the motor’s three-phase power supply has been cut off. Temperature readings are taken from a thermistor (DHT22) that is attached to the motor. At higher temperatures, the three-phase supply will be cut off by a four-pole contactor, and the motor will shut off. This manuscript resolves the uses transformers to solve the problem of single phasing. Also, our project addresses the issue by using microcontroller. It senses all the three phases and decides whether to supply power to induction motor or to disconnect. It deals with the temperature problem, and it uses a thermistor to disconnect the circuitry, whereas in our project, a microcontroller senses the overwhelming temperature and acts accordingly, i.e., give a signal and then move towards disconnection.
{"title":"Protection System Design of Induction Motor for Industries","authors":"Shoaib Sheikh, Dileep Kumar, Abdul Hakeem, Arsalan Muhammad Soomar","doi":"10.1155/2022/7423018","DOIUrl":"https://doi.org/10.1155/2022/7423018","url":null,"abstract":"The fundamental and durable structures of induction motor, as well as their low manufacturing cost, make them popular components in a wide range of current applications. Providing a safety net for employees is a must-have for businesses. This project’s motivation for improvement is to provide industrial motors, lift motors, pumps, and so on with safety. An induction motor’s primary goal is to protect it from problems, such as single phasing and overheating, as well as other issues. Providing industrial motors, pumps, lift motors, and other similar devices with security is a major motivation behind the emergence of this issue. Any of the three phases missing or the motor temperature above the predetermined threshold causes the motor to stop instantly. Three one-stage transformers are connected to a three-phase power supply in the system. Power will be cut to the transformer circuit if any phase is available. Motors can be turned off by relays sending a signal to the four-pole contactor. As a result, the motor’s three-phase power supply has been cut off. Temperature readings are taken from a thermistor (DHT22) that is attached to the motor. At higher temperatures, the three-phase supply will be cut off by a four-pole contactor, and the motor will shut off. This manuscript resolves the uses transformers to solve the problem of single phasing. Also, our project addresses the issue by using microcontroller. It senses all the three phases and decides whether to supply power to induction motor or to disconnect. It deals with the temperature problem, and it uses a thermistor to disconnect the circuitry, whereas in our project, a microcontroller senses the overwhelming temperature and acts accordingly, i.e., give a signal and then move towards disconnection.","PeriodicalId":45541,"journal":{"name":"Modelling and Simulation in Engineering","volume":"1 1","pages":""},"PeriodicalIF":3.2,"publicationDate":"2022-08-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"74963254","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
People who sit incorrectly can have musculoskeletal disorders like cervical spondylosis and lumbar vertebra disease, but without the guidance of a health care professional, it is difficult for people to evaluate their posture and adopt a more appropriate posture. Therefore, to solve this problem, we established a multilevel sitting posture evaluation system by analyzing the parameters such as joint angle, joint torque, joint force, and muscle force. Use the analytic hierarchy process and entropy comprehensive weighting method to weight evaluation indicators. According to their evaluation standards, each parameter is given weight after quantization and normalization. Firstly, take several sitting postures that often appear in office work as examples and use the lower back analysis and joint and static pressure analysis tools in JACK software for simulation analysis. Then, the weights of various parameters such as joints and muscles of the human body were calculated using the hierarchy analysis and entropy weight method, and the quantitative evaluation system of office sitting comfort was constructed. We recruited 50 subjects for an office simulation experiment to verify the feasibility of the evaluation index. Finally, we classified the sitting posture and selected those commonly used in life for evaluation. The proposed sitting posture evaluation system can objectively and comprehensively reflect the quality of sitting posture and guide people to adopt what kind of sitting posture.
{"title":"Construction of Evaluation Index System of Office Sitting Comfort Based on Ergonomics","authors":"Jiadian Hu, Shoudong Shi, Jiaqing Zheng, Zhiyuan Fang","doi":"10.1155/2022/5909778","DOIUrl":"https://doi.org/10.1155/2022/5909778","url":null,"abstract":"People who sit incorrectly can have musculoskeletal disorders like cervical spondylosis and lumbar vertebra disease, but without the guidance of a health care professional, it is difficult for people to evaluate their posture and adopt a more appropriate posture. Therefore, to solve this problem, we established a multilevel sitting posture evaluation system by analyzing the parameters such as joint angle, joint torque, joint force, and muscle force. Use the analytic hierarchy process and entropy comprehensive weighting method to weight evaluation indicators. According to their evaluation standards, each parameter is given weight after quantization and normalization. Firstly, take several sitting postures that often appear in office work as examples and use the lower back analysis and joint and static pressure analysis tools in JACK software for simulation analysis. Then, the weights of various parameters such as joints and muscles of the human body were calculated using the hierarchy analysis and entropy weight method, and the quantitative evaluation system of office sitting comfort was constructed. We recruited 50 subjects for an office simulation experiment to verify the feasibility of the evaluation index. Finally, we classified the sitting posture and selected those commonly used in life for evaluation. The proposed sitting posture evaluation system can objectively and comprehensively reflect the quality of sitting posture and guide people to adopt what kind of sitting posture.","PeriodicalId":45541,"journal":{"name":"Modelling and Simulation in Engineering","volume":"19 1","pages":""},"PeriodicalIF":3.2,"publicationDate":"2022-08-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83804578","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Imtiaz Ul Hassan, Huma Zia, H. S. Fatima, S. Yusuf, M. Khurram
End-to-end learning for autonomous driving uses a convolutional neural network (CNN) to predict the steering angle from a raw image input. Most of the solutions available for end-to-end autonomous driving are computationally too expensive, which increases the inference of autonomous driving in real time. Therefore, in this paper, CNN architecture has been trained which is lightweight and achieves comparable results to Nvidia’s PilotNet. The data used to train and evaluate the network is collected from the Car Learning to Act (CARLA) simulator. To evaluate the proposed architecture, the MSE (mean squared error) is used as the performance metric. Results of the experiment shows that the proposed model is 4x lighter than Nvidia’s PilotNet in term of parameters but still attains comparable results to PilotNet. The proposed model has achieved 5.1 × 10 − 4 MSE on testing data while PilotNet MSE was 4.7 × 10 − 4 .
{"title":"A Lightweight Convolutional Neural Network to Predict Steering Angle for Autonomous Driving Using CARLA Simulator","authors":"Imtiaz Ul Hassan, Huma Zia, H. S. Fatima, S. Yusuf, M. Khurram","doi":"10.1155/2022/5716820","DOIUrl":"https://doi.org/10.1155/2022/5716820","url":null,"abstract":"End-to-end learning for autonomous driving uses a convolutional neural network (CNN) to predict the steering angle from a raw image input. Most of the solutions available for end-to-end autonomous driving are computationally too expensive, which increases the inference of autonomous driving in real time. Therefore, in this paper, CNN architecture has been trained which is lightweight and achieves comparable results to Nvidia’s PilotNet. The data used to train and evaluate the network is collected from the Car Learning to Act (CARLA) simulator. To evaluate the proposed architecture, the MSE (mean squared error) is used as the performance metric. Results of the experiment shows that the proposed model is 4x lighter than Nvidia’s PilotNet in term of parameters but still attains comparable results to PilotNet. The proposed model has achieved \u0000 \u0000 5.1\u0000 ×\u0000 \u0000 \u0000 10\u0000 \u0000 \u0000 −\u0000 4\u0000 \u0000 \u0000 \u0000 MSE on testing data while PilotNet MSE was \u0000 \u0000 4.7\u0000 ×\u0000 \u0000 \u0000 10\u0000 \u0000 \u0000 −\u0000 4\u0000 \u0000 \u0000 \u0000 .","PeriodicalId":45541,"journal":{"name":"Modelling and Simulation in Engineering","volume":"145 1","pages":""},"PeriodicalIF":3.2,"publicationDate":"2022-08-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75959431","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
In the real applications, we found that it is difficult to achieve good control performance through manually tuning proportional–integral (PI) parameters of phase locked loop (PLL) and speed-loop of Luenberger observer (LO) for the PMSM sensorless control system. Therefore, this paper is to use the particle swarm optimization (PSO) algorithm to optimize the PI parameters of PLL and speed-loop of Luenberger observer of the system. Firstly, the ranges of PLL parameters are obtained by analyzing the PLL subsystem stability. Then, the ranges of PI parameters of PLL and speed-loop are set based on theoretical estimation and empirical values. The control system model is realized in MATLAB/Simulink that considers the constraints such as the saturation. The integral time absolute error is the objective function, and the PSO with different topologies is used to optimize the PI parameters. The simulation and experimental results show that the proposed method is feasible, and the optimized parameters can effectively improve the precision of position estimation and speed estimation. Moreover, the simulations and experiments are carried out to verify the robustness of the proposed method, and the results show that the optimized system can achieve good performance when there are uncertainties or disturbances.
{"title":"Optimized Luenberger Observer-Based PMSM Sensorless Control by PSO","authors":"Rongfu Luo, Zenghui Wang, Yanxia Sun","doi":"10.1155/2022/3328719","DOIUrl":"https://doi.org/10.1155/2022/3328719","url":null,"abstract":"In the real applications, we found that it is difficult to achieve good control performance through manually tuning proportional–integral (PI) parameters of phase locked loop (PLL) and speed-loop of Luenberger observer (LO) for the PMSM sensorless control system. Therefore, this paper is to use the particle swarm optimization (PSO) algorithm to optimize the PI parameters of PLL and speed-loop of Luenberger observer of the system. Firstly, the ranges of PLL parameters are obtained by analyzing the PLL subsystem stability. Then, the ranges of PI parameters of PLL and speed-loop are set based on theoretical estimation and empirical values. The control system model is realized in MATLAB/Simulink that considers the constraints such as the saturation. The integral time absolute error is the objective function, and the PSO with different topologies is used to optimize the PI parameters. The simulation and experimental results show that the proposed method is feasible, and the optimized parameters can effectively improve the precision of position estimation and speed estimation. Moreover, the simulations and experiments are carried out to verify the robustness of the proposed method, and the results show that the optimized system can achieve good performance when there are uncertainties or disturbances.","PeriodicalId":45541,"journal":{"name":"Modelling and Simulation in Engineering","volume":"11 1","pages":""},"PeriodicalIF":3.2,"publicationDate":"2022-08-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77038743","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
B. Falodun, A. J. Omowaye, F. Oyelami, H. Emadifar, Ahmad Hamod, S. Atif
The Cattaneo-Christov model will be used to examine the significance of heat generation, viscous dissipation, and thermal radiation on a double-diffusive MHD flow in this study. In this study, it was discovered that heat and mass transfer can be affected by nonlinear buoyancy significance. The flow direction was subjected to a uniform magnetic field. A set of partial differential equations governs the current design (PDEs). In order to simplify these equations, they are converted into ordinary differential equations (ODEs). In order to numerically solve the nonlinear ODEs, the spectral relaxation method (SRM) is utilized. In order to decouple and linearize the equation sets, the SRM employs the Gauss-Seidel relaxation method. Geothermal power generation and underground storage systems are just a few examples where this research could be put to use. When compared to previous findings, the current outcomes were discovered to be closely related. Owing to an increase in Lorentz force, the imposed magnetic field slows down fluid motion. Viscosity dissipation and heat generation all contribute to the formation of an ever-thicker thermal boundary layer. When the Cattaneo-Christov models are used, the thermal and concentration boundary layers get a lot thicker.
{"title":"Double-Diffusive MHD Viscous Fluid Flow in a Porous Medium in the Presence of Cattaneo-Christov Theories","authors":"B. Falodun, A. J. Omowaye, F. Oyelami, H. Emadifar, Ahmad Hamod, S. Atif","doi":"10.1155/2022/2533714","DOIUrl":"https://doi.org/10.1155/2022/2533714","url":null,"abstract":"The Cattaneo-Christov model will be used to examine the significance of heat generation, viscous dissipation, and thermal radiation on a double-diffusive MHD flow in this study. In this study, it was discovered that heat and mass transfer can be affected by nonlinear buoyancy significance. The flow direction was subjected to a uniform magnetic field. A set of partial differential equations governs the current design (PDEs). In order to simplify these equations, they are converted into ordinary differential equations (ODEs). In order to numerically solve the nonlinear ODEs, the spectral relaxation method (SRM) is utilized. In order to decouple and linearize the equation sets, the SRM employs the Gauss-Seidel relaxation method. Geothermal power generation and underground storage systems are just a few examples where this research could be put to use. When compared to previous findings, the current outcomes were discovered to be closely related. Owing to an increase in Lorentz force, the imposed magnetic field slows down fluid motion. Viscosity dissipation and heat generation all contribute to the formation of an ever-thicker thermal boundary layer. When the Cattaneo-Christov models are used, the thermal and concentration boundary layers get a lot thicker.","PeriodicalId":45541,"journal":{"name":"Modelling and Simulation in Engineering","volume":"25 1","pages":""},"PeriodicalIF":3.2,"publicationDate":"2022-08-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"85408469","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
CFD analysis of flow and heat transfer characteristics in a baffled duct is reported. The baffle locations ( s = 0.05 H – 0.40 H ), flow paths (V-apex directing Downstream or VD and V-apex directing Upstream or VU), and baffle heights ( b = 0.05 H – 0.30 H ) are investigated in the laminar flow regime with the Reynolds number based on the entry conditions between 100 and 2,000. Solutions of the present work are obtained by the finite volume method (a commercial code). Key mechanisms such as fluid streams, impinging streams, and disturbed thermal boundary layer in the baffled duct are observed. The baffle locations have high impact on flow and heat transfer behavior. The best heat transfer rate of the baffled duct is 15.55 times higher than that of the general duct with no baffle, while the optimum TEF is 4.06.
本文报道了折流板管内流动和传热特性的CFD分析。在雷诺数为100 ~ 2000的层流条件下，研究了挡板位置(s = 0.05 H ~ 0.40 H)、流道(v -顶点指向下游或VD和v -顶点指向上游或VU)和挡板高度(b = 0.05 H ~ 0.30 H)。本文采用有限体积法(商业规范)求解。观察了折流管中流体流动、碰撞流和扰动热边界层等关键机理。挡板的位置对流动和传热行为有很大的影响。折流板风管的最佳换热率是普通无折流板风管的15.55倍，最佳TEF为4.06。
{"title":"Effects of Baffle Height and Baffle Location on Heat Transfer and Flow Profiles in a Baffled Duct: A CFD Analysis","authors":"A. Boonloi, W. Jedsadaratanachai","doi":"10.1155/2022/3698887","DOIUrl":"https://doi.org/10.1155/2022/3698887","url":null,"abstract":"CFD analysis of flow and heat transfer characteristics in a baffled duct is reported. The baffle locations (\u0000 \u0000 s\u0000 =\u0000 0.05\u0000 H\u0000 –\u0000 0.40\u0000 H\u0000 \u0000 ), flow paths (V-apex directing Downstream or VD and V-apex directing Upstream or VU), and baffle heights (\u0000 \u0000 b\u0000 =\u0000 0.05\u0000 H\u0000 –\u0000 0.30\u0000 H\u0000 \u0000 ) are investigated in the laminar flow regime with the Reynolds number based on the entry conditions between 100 and 2,000. Solutions of the present work are obtained by the finite volume method (a commercial code). Key mechanisms such as fluid streams, impinging streams, and disturbed thermal boundary layer in the baffled duct are observed. The baffle locations have high impact on flow and heat transfer behavior. The best heat transfer rate of the baffled duct is 15.55 times higher than that of the general duct with no baffle, while the optimum TEF is 4.06.","PeriodicalId":45541,"journal":{"name":"Modelling and Simulation in Engineering","volume":"19 1","pages":""},"PeriodicalIF":3.2,"publicationDate":"2022-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"85346972","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Calequela J. T. Manuel, Max M. D. Santos, G. Lenzi, Â. Tusset
This paper validates and analyzes the robustness of the proportional-integral-derivative (PID) action controller from an open transfer function that integrates a proportional-integral (PI) action controller to obtain the response of a robust action control during the automatic parking maneuver of a vehicle where the simulations are based on 3 adjustment methods: Ziegler-Nichols (ZN), Chien-Hrones-Reswick (CHR), and Cohen-Coon (CC), and as a result of the computer simulations, it is determined the best performance index of the PID controller represented by mathematical and graphic equations with the help of MATLAB/Simulink software.
{"title":"Computational Validation of the Best Tuning Method for a Vehicle-Integrated PID Controller","authors":"Calequela J. T. Manuel, Max M. D. Santos, G. Lenzi, Â. Tusset","doi":"10.1155/2022/3873639","DOIUrl":"https://doi.org/10.1155/2022/3873639","url":null,"abstract":"This paper validates and analyzes the robustness of the proportional-integral-derivative (PID) action controller from an open transfer function that integrates a proportional-integral (PI) action controller to obtain the response of a robust action control during the automatic parking maneuver of a vehicle where the simulations are based on 3 adjustment methods: Ziegler-Nichols (ZN), Chien-Hrones-Reswick (CHR), and Cohen-Coon (CC), and as a result of the computer simulations, it is determined the best performance index of the PID controller represented by mathematical and graphic equations with the help of MATLAB/Simulink software.","PeriodicalId":45541,"journal":{"name":"Modelling and Simulation in Engineering","volume":"67 1","pages":""},"PeriodicalIF":3.2,"publicationDate":"2022-06-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77976620","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Yuanying Gan, Chuntong Liu, Zhen-xin He, Hongcai Li, Zhongye Liu
Digital camouflage is a common countermeasure against military reconnaissance. In the face of high-tech imaging reconnaissance, battlefield detection means tend to be automated and refined. In order to adapt to the concealment requirements under various environmental backgrounds, combined with the camouflage performance of digital camouflage and its feedback mechanism in camouflage pattern design, this paper proposed a digital camouflage pattern design method based on biased random walk. Firstly, the original background is preprocessed, and the background texture’s direction, corner, step length, and pixel intensity difference are statistically analyzed, and the boundary probability between pixel nodes is estimated. Then, a biased random walk is used to outline the camouflage patches. The edge scatter is enriched according to the density of the patches, and the camouflage patches are filled according to the proportion of the main color of the background. Finally, a digital camouflage pattern is obtained. The quantitative analysis results show that the mean heart rate of the digital camouflage pattern based on multiscene design is at least 31.0% higher than that of the original background segmentation texture, and the standard deviation index of equivalent diameter is increased by 14.9% on average. In addition, the results of simulation camouflage image detection in multiple scenes show that the proposed method can effectively deal with camouflage target detection on the basis of fully retaining the original background texture information and has strong camouflage concealment effect in the scene.
{"title":"Digital Camouflage Pattern Design Based on the Biased Random Walk","authors":"Yuanying Gan, Chuntong Liu, Zhen-xin He, Hongcai Li, Zhongye Liu","doi":"10.1155/2022/2986346","DOIUrl":"https://doi.org/10.1155/2022/2986346","url":null,"abstract":"Digital camouflage is a common countermeasure against military reconnaissance. In the face of high-tech imaging reconnaissance, battlefield detection means tend to be automated and refined. In order to adapt to the concealment requirements under various environmental backgrounds, combined with the camouflage performance of digital camouflage and its feedback mechanism in camouflage pattern design, this paper proposed a digital camouflage pattern design method based on biased random walk. Firstly, the original background is preprocessed, and the background texture’s direction, corner, step length, and pixel intensity difference are statistically analyzed, and the boundary probability between pixel nodes is estimated. Then, a biased random walk is used to outline the camouflage patches. The edge scatter is enriched according to the density of the patches, and the camouflage patches are filled according to the proportion of the main color of the background. Finally, a digital camouflage pattern is obtained. The quantitative analysis results show that the mean heart rate of the digital camouflage pattern based on multiscene design is at least 31.0% higher than that of the original background segmentation texture, and the standard deviation index of equivalent diameter is increased by 14.9% on average. In addition, the results of simulation camouflage image detection in multiple scenes show that the proposed method can effectively deal with camouflage target detection on the basis of fully retaining the original background texture information and has strong camouflage concealment effect in the scene.","PeriodicalId":45541,"journal":{"name":"Modelling and Simulation in Engineering","volume":"13 1","pages":""},"PeriodicalIF":3.2,"publicationDate":"2022-06-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"88678537","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The failure of electric feeders is a common problem in the summer season in Pakistan. In this article, one of the troubling aspects of the electric power system of Pakistan (Multan city) has been studied. The time lapses between the breakdown of electric feeders of the city have been modeled by suggesting an inverse Rayleigh-exponential distribution. The parameters of the distribution are estimated in both the frequentist and Bayesian paradigms. Since the Bayes estimators under informative priors are not attained in the closed form, this paper provides a comparative analysis of the Bayes estimators under Lindley and Tierney–Kadane approximation methods. The simulation study and the real-life data set assessed the validity of the model and the superiority of the Bayes estimators over the maximum likelihood estimators.
{"title":"Modeling and Bayesian Analysis of Time between the Breakdown of Electric Feeders","authors":"Kahkashan Ateeq, Saima Altaf, Muhammad Aslam","doi":"10.1155/2022/5830945","DOIUrl":"https://doi.org/10.1155/2022/5830945","url":null,"abstract":"The failure of electric feeders is a common problem in the summer season in Pakistan. In this article, one of the troubling aspects of the electric power system of Pakistan (Multan city) has been studied. The time lapses between the breakdown of electric feeders of the city have been modeled by suggesting an inverse Rayleigh-exponential distribution. The parameters of the distribution are estimated in both the frequentist and Bayesian paradigms. Since the Bayes estimators under informative priors are not attained in the closed form, this paper provides a comparative analysis of the Bayes estimators under Lindley and Tierney–Kadane approximation methods. The simulation study and the real-life data set assessed the validity of the model and the superiority of the Bayes estimators over the maximum likelihood estimators.","PeriodicalId":45541,"journal":{"name":"Modelling and Simulation in Engineering","volume":"57 1","pages":""},"PeriodicalIF":3.2,"publicationDate":"2022-05-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90898997","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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