Pub Date : 2021-04-07DOI: 10.12783/DTMSE/AMEME2020/35585
Kaiming Xu, Rao Zhu, Liu Zhonghua, Chen Hong, Gao Dapeng
In the dual-machine wind tunnel test, the rear machine model support system is an open chain mechanism composed of rigid links in series with rotation and translation functions, and belongs to a multi-rigid body link system. The kinematic analysis of the system is to use the centroid of the posterior model as the end position of the mechanism, and analyze the relationship between the position and posture of the centroid of the model and the space of each joint variable. [1] Therefore, in order to study the motion control system of the model support system and the dual-camera pose simulation, the kinematics analysis of the back-machine model support system is first required. Based on this analysis, a cloud image of the working space of the model support mechanism is established to ensure that it does not collide with the side wall of the wind tunnel. 1 Solution to the kinematic equations of the supporting system The structure of the back machine model support device is shown in Figure 1. The movement mechanism includes: 1) Movement mechanism between the height direction; 2) Yaw mechanism 1, the yaw angle adjustment is realized by the electric cylinder through the rod mechanism; 3) Yaw mechanism 2, the yaw angle adjustment is realized by the electric cylinder through the rod mechanism; 4) Pitch motion mechanism 3, the angle is adjusted by the electric cylinder through the rod mechanism; 5) The horizontal linear adjustment mechanism 4 uses a hydraulic cylinder to adjust the length of the rod through a rod mechanism. The end is the fixed surface of the airplane model, and here is the end of the mechanism in this paper.
{"title":"A Study on the Kinematics of the Model Support System of the Dual-Machine Wind Tunnel Test","authors":"Kaiming Xu, Rao Zhu, Liu Zhonghua, Chen Hong, Gao Dapeng","doi":"10.12783/DTMSE/AMEME2020/35585","DOIUrl":"https://doi.org/10.12783/DTMSE/AMEME2020/35585","url":null,"abstract":"In the dual-machine wind tunnel test, the rear machine model support system is an open chain mechanism composed of rigid links in series with rotation and translation functions, and belongs to a multi-rigid body link system. The kinematic analysis of the system is to use the centroid of the posterior model as the end position of the mechanism, and analyze the relationship between the position and posture of the centroid of the model and the space of each joint variable. [1] Therefore, in order to study the motion control system of the model support system and the dual-camera pose simulation, the kinematics analysis of the back-machine model support system is first required. Based on this analysis, a cloud image of the working space of the model support mechanism is established to ensure that it does not collide with the side wall of the wind tunnel. 1 Solution to the kinematic equations of the supporting system The structure of the back machine model support device is shown in Figure 1. The movement mechanism includes: 1) Movement mechanism between the height direction; 2) Yaw mechanism 1, the yaw angle adjustment is realized by the electric cylinder through the rod mechanism; 3) Yaw mechanism 2, the yaw angle adjustment is realized by the electric cylinder through the rod mechanism; 4) Pitch motion mechanism 3, the angle is adjusted by the electric cylinder through the rod mechanism; 5) The horizontal linear adjustment mechanism 4 uses a hydraulic cylinder to adjust the length of the rod through a rod mechanism. The end is the fixed surface of the airplane model, and here is the end of the mechanism in this paper.","PeriodicalId":11124,"journal":{"name":"DEStech Transactions on Materials Science and Engineering","volume":"27 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-04-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90823617","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}
Pub Date : 2021-04-07DOI: 10.12783/DTMSE/AMEME2020/35539
F. Xu, Hui Liu, Huanling Wang, Haiyan Xing
Aiming at the problem of large drag force of robot in narrow pipe space, a new type walking driving mechanism of in-pipe worming robot was proposed in this paper. The main force-exerting driving is an incomplete gear-rack mechanism, it has the characteristics of high transmission efficiency and good manufacturability. The walking principle and walking step-speed and drag force had been analyzed. When virtual prototype established the simulation experiments analysis were completed, the numerical results are in good agreement with the theoretical analysis, to a certain extent, the rationality and feasibility of the new type walking driving mechanism proposed of in-pipe worming robot had been verified, these provide the basis foundation for the manufacture of physical prototype.
{"title":"Research and Simulation on Principle of Walking Driving Mechanism for In-Pipe Worming Robot","authors":"F. Xu, Hui Liu, Huanling Wang, Haiyan Xing","doi":"10.12783/DTMSE/AMEME2020/35539","DOIUrl":"https://doi.org/10.12783/DTMSE/AMEME2020/35539","url":null,"abstract":"Aiming at the problem of large drag force of robot in narrow pipe space, a new type walking driving mechanism of in-pipe worming robot was proposed in this paper. The main force-exerting driving is an incomplete gear-rack mechanism, it has the characteristics of high transmission efficiency and good manufacturability. The walking principle and walking step-speed and drag force had been analyzed. When virtual prototype established the simulation experiments analysis were completed, the numerical results are in good agreement with the theoretical analysis, to a certain extent, the rationality and feasibility of the new type walking driving mechanism proposed of in-pipe worming robot had been verified, these provide the basis foundation for the manufacture of physical prototype.","PeriodicalId":11124,"journal":{"name":"DEStech Transactions on Materials Science and Engineering","volume":"44 6","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-04-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"91503695","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}
Pub Date : 2021-04-07DOI: 10.12783/DTMSE/AMEME2020/35541
Chen Yongqiang, Hong Ma, Jiao Yiwen, Yandu Liu
In order to upgrade the VLBI digital baseband converter of China's Deep Space Network (CDSN), a CUDA-based design method for polyphase channelized VLBI digital baseband equipment is proposed. Firstly, the parallelism of each module of the baseband conversion algorithm is analysed. Then the overall implementation structure of the polyphase channelization algorithm and the kernel of each module are implemented based on CUDA Stream. Finally, the indexes of the system are tested by simulation experiments. The results show that the system designed in this paper is flexible, simple and efficient, and can meet the requirements of CDSN VLBI system.
{"title":"Implementation of VLBI Digital Baseband Converter with CUDA","authors":"Chen Yongqiang, Hong Ma, Jiao Yiwen, Yandu Liu","doi":"10.12783/DTMSE/AMEME2020/35541","DOIUrl":"https://doi.org/10.12783/DTMSE/AMEME2020/35541","url":null,"abstract":"In order to upgrade the VLBI digital baseband converter of China's Deep Space Network (CDSN), a CUDA-based design method for polyphase channelized VLBI digital baseband equipment is proposed. Firstly, the parallelism of each module of the baseband conversion algorithm is analysed. Then the overall implementation structure of the polyphase channelization algorithm and the kernel of each module are implemented based on CUDA Stream. Finally, the indexes of the system are tested by simulation experiments. The results show that the system designed in this paper is flexible, simple and efficient, and can meet the requirements of CDSN VLBI system.","PeriodicalId":11124,"journal":{"name":"DEStech Transactions on Materials Science and Engineering","volume":"22 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-04-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86717939","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}
Pub Date : 2021-04-07DOI: 10.12783/DTMSE/AMEME2020/35545
Xu Cui, Ming-Daw Wu, Changlin Zhao
In this study, quare, kagome and triangular grid sandwich structures about carbon fibre reinforced epoxy (CF/EP) composite, were designed and manufactured. Mechanical properties of these designed sandwich structures were performed by three-point bending and finite element analysis (FEA). The bending stiffness and core shear stress were calculated and then compared. Results obtained indicate that stress concentration was found at loading regions that cracks occurred on the interface. The face yielding and core shear failure also play a key role in the sandwich grid structure. The results show that the carbon fibre fabricated triangular grid core has a much stiffer and stronger character than other structures.
{"title":"Mechanical Properties and Failure Analysis of Lattice Grid Sandwich Structure","authors":"Xu Cui, Ming-Daw Wu, Changlin Zhao","doi":"10.12783/DTMSE/AMEME2020/35545","DOIUrl":"https://doi.org/10.12783/DTMSE/AMEME2020/35545","url":null,"abstract":"In this study, quare, kagome and triangular grid sandwich structures about carbon fibre reinforced epoxy (CF/EP) composite, were designed and manufactured. Mechanical properties of these designed sandwich structures were performed by three-point bending and finite element analysis (FEA). The bending stiffness and core shear stress were calculated and then compared. Results obtained indicate that stress concentration was found at loading regions that cracks occurred on the interface. The face yielding and core shear failure also play a key role in the sandwich grid structure. The results show that the carbon fibre fabricated triangular grid core has a much stiffer and stronger character than other structures.","PeriodicalId":11124,"journal":{"name":"DEStech Transactions on Materials Science and Engineering","volume":"2016 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-04-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86124459","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 order to study the influencing factors of residents' willingness to classify garbage in Harbin, countermeasures and suggestions are made according to the analysis results of the influencing factors. In this paper, questionnaire data were obtained by combining field questionnaire distribution and online questionnaire distribution in Harbin. SEM was used for correlation analysis of questionnaire data. The analysis results showed that age and income had a significant positive impact on residents' willingness to classify garbage, and older female groups were more familiar with garbage classification and more willing to conduct garbage classification. Based on the analysis results, this paper puts forward feasible suggestions for Harbin to implement the garbage classification policies.
{"title":"Investigation and Analysis of Residents’ Willingness to Sort Garbage in Harbin","authors":"Xue Li, Chang-sen Lv, Weicheng Wang, Junyu Yang, Tianying Du, Jiawen Ding","doi":"10.12783/DTMSE/AMEME2020/35576","DOIUrl":"https://doi.org/10.12783/DTMSE/AMEME2020/35576","url":null,"abstract":"In order to study the influencing factors of residents' willingness to classify garbage in Harbin, countermeasures and suggestions are made according to the analysis results of the influencing factors. In this paper, questionnaire data were obtained by combining field questionnaire distribution and online questionnaire distribution in Harbin. SEM was used for correlation analysis of questionnaire data. The analysis results showed that age and income had a significant positive impact on residents' willingness to classify garbage, and older female groups were more familiar with garbage classification and more willing to conduct garbage classification. Based on the analysis results, this paper puts forward feasible suggestions for Harbin to implement the garbage classification policies.","PeriodicalId":11124,"journal":{"name":"DEStech Transactions on Materials Science and Engineering","volume":"2002 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-04-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"88376742","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}
Pub Date : 2021-04-07DOI: 10.12783/DTMSE/AMEME2020/35579
Weifeng Zhang, Jin Zhengjun, Shuxuan Song, Tao Feng, Yisheng Mao
With the rapid development of electric vehicle industry in China, the contradiction between the increasing users' demand for real-time charging and the unbalanced planning and design of charging piles is increasingly apparent. DC charging pile on the market is developed rapidly, but its structure is with multi-gun to one-pile. It is difficult to meet the demand of different kinds of electric vehicle battery charging, different battery capacity and the user expected charging time. To solve the problems, a flexible power distribution method of DC charging pile is proposed in this paper. When multiple EV in different types and states are charged at the same time, and the actual charging demands of each user and the charging battery are considered, the power module can be dynamically switched to realize the flexible power distribution, the idea of flexible power distribution is described. Then the algorithm steps of power distribution were presented. Finally, the Matlab/Simulink was used for example analysis to simulate the power distribution process when different initial SOC batteries were charged simultaneously.
{"title":"Flexible Power Distribution Technology Based on Modular DC Charging Pile","authors":"Weifeng Zhang, Jin Zhengjun, Shuxuan Song, Tao Feng, Yisheng Mao","doi":"10.12783/DTMSE/AMEME2020/35579","DOIUrl":"https://doi.org/10.12783/DTMSE/AMEME2020/35579","url":null,"abstract":"With the rapid development of electric vehicle industry in China, the contradiction between the increasing users' demand for real-time charging and the unbalanced planning and design of charging piles is increasingly apparent. DC charging pile on the market is developed rapidly, but its structure is with multi-gun to one-pile. It is difficult to meet the demand of different kinds of electric vehicle battery charging, different battery capacity and the user expected charging time. To solve the problems, a flexible power distribution method of DC charging pile is proposed in this paper. When multiple EV in different types and states are charged at the same time, and the actual charging demands of each user and the charging battery are considered, the power module can be dynamically switched to realize the flexible power distribution, the idea of flexible power distribution is described. Then the algorithm steps of power distribution were presented. Finally, the Matlab/Simulink was used for example analysis to simulate the power distribution process when different initial SOC batteries were charged simultaneously.","PeriodicalId":11124,"journal":{"name":"DEStech Transactions on Materials Science and Engineering","volume":"1 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-04-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"89109815","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}
Pub Date : 2021-04-07DOI: 10.12783/DTMSE/AMEME2020/35560
Zhenxing Chang, Zhihua Li, Bolong Lei, Tao Chen, Guanning Wang, Huijie Zheng, Na Ma
As an education base, colleges and universities provide a large number of excellent talents for the country and the society. Campus security is bound to be highly valued by all sectors of society. However, current campus security incidents occur frequently and often appear in the media at the first time, which is easy to arouse wide attention of the society and the government. Because of its particularity, universities will face greater challenges when security incidents occur. Taking Tsinghua University as an example, this paper discusses the construction of an information platform for comprehensive security on campus, so as to make up for the deficiencies of traditional civil air defense and physical defense, better guarantee the safety of all kinds of school personnel, and provide reference for other colleges and universities to build a comprehensive security information platform.
{"title":"Research on the Construction of Campus Security Information Platform","authors":"Zhenxing Chang, Zhihua Li, Bolong Lei, Tao Chen, Guanning Wang, Huijie Zheng, Na Ma","doi":"10.12783/DTMSE/AMEME2020/35560","DOIUrl":"https://doi.org/10.12783/DTMSE/AMEME2020/35560","url":null,"abstract":"As an education base, colleges and universities provide a large number of excellent talents for the country and the society. Campus security is bound to be highly valued by all sectors of society. However, current campus security incidents occur frequently and often appear in the media at the first time, which is easy to arouse wide attention of the society and the government. Because of its particularity, universities will face greater challenges when security incidents occur. Taking Tsinghua University as an example, this paper discusses the construction of an information platform for comprehensive security on campus, so as to make up for the deficiencies of traditional civil air defense and physical defense, better guarantee the safety of all kinds of school personnel, and provide reference for other colleges and universities to build a comprehensive security information platform.","PeriodicalId":11124,"journal":{"name":"DEStech Transactions on Materials Science and Engineering","volume":"40 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-04-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75510556","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}
Through the technical analysis of many cracks and leaks occurred in the pressure vessel attached to the gas injection compressor during its long service period at high pressure, the chemical analysis, metallographic analysis, hardness measurement, finite element analysis and vibration monitoring of the three-stage outlet spherical tank were carried out. Finally, it is determined that the causes of the defects are the high hardness and stress values of the weld seam and heat affected zone of the nozzle, and the mechanical fatigue caused by the alternating load caused by the vibration of the unit.
{"title":"Cause Analysis of Weld Crack of Pressure Vessel Attached to Gas Injection Compressor","authors":"Xunji Li, Fushan Wang, Zifeng Yan, Yajun Li, Daoyong Gong, Wei Xing, Yufu Zhang, Hou-de Su","doi":"10.12783/DTMSE/AMEME2020/35565","DOIUrl":"https://doi.org/10.12783/DTMSE/AMEME2020/35565","url":null,"abstract":"Through the technical analysis of many cracks and leaks occurred in the pressure vessel attached to the gas injection compressor during its long service period at high pressure, the chemical analysis, metallographic analysis, hardness measurement, finite element analysis and vibration monitoring of the three-stage outlet spherical tank were carried out. Finally, it is determined that the causes of the defects are the high hardness and stress values of the weld seam and heat affected zone of the nozzle, and the mechanical fatigue caused by the alternating load caused by the vibration of the unit.","PeriodicalId":11124,"journal":{"name":"DEStech Transactions on Materials Science and Engineering","volume":"1 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-04-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81841690","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}
Pub Date : 2021-04-07DOI: 10.12783/DTMSE/AMEME2020/35532
L. Meng, Wei Qu, Kai Cai
With the increasing complexity of electromagnetic environment and the rising of operating patterns of new radars, emitter identification is becoming more and more difficult. This paper presents a radar emitter identification method based on stacked long and short term memory (SLSTM). Radar pulse train can be directly used as input without extracting other features, which greatly simplifies the data preprocessing and realizes the "end-to-end" recognition of radar emitter signal. The timing characteristics of the pulses are automatically extracted by SLSTM, and the optimal network parameters are trained to complete radar signal identification. Compared experiments with conventional methods are conducted, and the results show that the proposed model outperforms other existing techniques. Moreover, simulation experiments in different noise and loss pulse environment show that the method is effective and robust in solving problems of radar emitter recognition.
{"title":"Radar Emitter Identification Based on Stacked Long and Short Term Memory","authors":"L. Meng, Wei Qu, Kai Cai","doi":"10.12783/DTMSE/AMEME2020/35532","DOIUrl":"https://doi.org/10.12783/DTMSE/AMEME2020/35532","url":null,"abstract":"With the increasing complexity of electromagnetic environment and the rising of operating patterns of new radars, emitter identification is becoming more and more difficult. This paper presents a radar emitter identification method based on stacked long and short term memory (SLSTM). Radar pulse train can be directly used as input without extracting other features, which greatly simplifies the data preprocessing and realizes the \"end-to-end\" recognition of radar emitter signal. The timing characteristics of the pulses are automatically extracted by SLSTM, and the optimal network parameters are trained to complete radar signal identification. Compared experiments with conventional methods are conducted, and the results show that the proposed model outperforms other existing techniques. Moreover, simulation experiments in different noise and loss pulse environment show that the method is effective and robust in solving problems of radar emitter recognition.","PeriodicalId":11124,"journal":{"name":"DEStech Transactions on Materials Science and Engineering","volume":"53 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-04-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"85774540","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}
Pub Date : 2021-04-07DOI: 10.12783/DTMSE/AMEME2020/35572
Fan Sun
{"title":"Exact Solutions for the (2 + 1)-Dimensional Nizhnik-Novikov-Veselov System","authors":"Fan Sun","doi":"10.12783/DTMSE/AMEME2020/35572","DOIUrl":"https://doi.org/10.12783/DTMSE/AMEME2020/35572","url":null,"abstract":"","PeriodicalId":11124,"journal":{"name":"DEStech Transactions on Materials Science and Engineering","volume":"1 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-04-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"89504683","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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