Xibei Gongye Daxue Xuebao/Journal of Northwestern Polytechnical University最新文献

{"title":"Search domain dimension expansion of robust matched-field source radiated power estimation","authors":"Shaodong Zhang, Chao Sun","doi":"10.1051/jnwpu/20244210001","DOIUrl":"https://doi.org/10.1051/jnwpu/20244210001","url":null,"abstract":"Compared with the traditional source radiated power estimation method, the matched-field source radiated power estimation method can obtain more accurate estimation results. However, its performance is greatly influenced by environmental mismatch. This paper defines the impact factor of environmental mismatch to quantify the impact of environmental mismatch on the acoustic transfer function and the matched-field source radiated power estimation method. It determines that the key to improve the robustness of environmental mismatch is to accurately estimate the acoustic transfer function. In the traditional matched-field source radiated power estimation method, the search domain of the acoustic transfer function is a distance-depth two-dimensional plane and does not contain the true acoustic transfer function when the environment is mismatched. Therefore, the estimation results of the acoustic transfer function are bound to deviate from those of the true acoustic transfer function. The paper expands the search domain dimension to a three-dimensional search domain that contains distance, depth and uncertain parameter sets. The true acoustic transfer function is included in the search domain. Thus the optimal alternative acoustic transfer function is equal to the true acoustic transfer function. The objective function for the three-dimensional search domain is constructed. The smaller the absolute value of the objective function, the less the acoustic transfer function estimation deviates from the true acoustic transfer function. The source radiated power is estimated more accurately when the alternative acoustic transfer function estimation corresponding to the minimum absolute value of the objective function. The simulation results verify the theoretical analysis results.","PeriodicalId":515230,"journal":{"name":"Xibei Gongye Daxue Xuebao/Journal of Northwestern Polytechnical University","volume":"193 ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140470362","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}

{"title":"Microscopic morphology modeling and prediction of flexible polished surface with belt flapwheel","authors":"Zhen Chen, Pan Zhao, Rui Yan, Nuo Shi, Kaining Shi, Yaoyao Shi","doi":"10.1051/jnwpu/20244210062","DOIUrl":"https://doi.org/10.1051/jnwpu/20244210062","url":null,"abstract":"Flexible polishing technology is widely used in the precision machining of aero-engine blisk blades. It has become one of the important research contents of flexible polishing technology to systematically study the flexible polishing process and understand the connotation of the microscopic morphology of the polished surface. In this paper, the flapwheel is used as a flexible abrasive tool, and the spatial kinematics model for the abrasive grains on the surface of the flapwheel and the geometric interference model for the abrasive grains and workpiece are established by transforming the spatial geometric coordinates. Based on the surface topography model for the abrasive tool, MATLAB software was used to simulate the micro topography generation process of the flexible polishing surface with flapwheel as abrasive tool, and the three-dimensional topography of the workpiece surface and its influence law under different process parameters were obtained. The polishing experimental results verified the simulation algorithm correctness and effectiveness.","PeriodicalId":515230,"journal":{"name":"Xibei Gongye Daxue Xuebao/Journal of Northwestern Polytechnical University","volume":"40 ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140463707","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}

{"title":"A logic obfuscation attack method based on gate-level information flow tracing techniques","authors":"Liang Liu, Jiacheng Zhu, Zhe Zhang, Lixiang Shen, Yufeng Sun, Dejun Mu","doi":"10.1051/jnwpu/20244210078","DOIUrl":"https://doi.org/10.1051/jnwpu/20244210078","url":null,"abstract":"Logical obfuscation technique is a mainstream technical means to achieve intellectual property protection and prevent reverse engineering. In this paper, we propose a logical obfuscation attack method based on the gate-level information flow tracking technique, using the information flow analysis method at the gate-level abstraction level, establishing an information flow model, constraining the output and its contamination labels, and solving the obfuscation key sequence satisfying the constraints using an SAT solver. The experimental results show that the attack method has good cracking effect and efficiency for benchmarks generated by five obfuscated encryption algorithms with two test area costs.","PeriodicalId":515230,"journal":{"name":"Xibei Gongye Daxue Xuebao/Journal of Northwestern Polytechnical University","volume":"37 6","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140463436","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}

{"title":"Investigation of overall performance of turbofan engine with pulse detonation combustor in bypass duct","authors":"Chenxu Peng, Longxi Zheng, Jie Lu, Zhenkun Luo, Jiabo Zhang","doi":"10.1051/jnwpu/20244210149","DOIUrl":"https://doi.org/10.1051/jnwpu/20244210149","url":null,"abstract":"The performance model was established to study the performance of mixed exhaust turbofan engine with pulse detonation combustor (PDC) in the bypass duct. The effects of the total pressure loss of isolator and bypass circulation parameters on the characteristic of PDC and performance of engine were analyzed. Then, the sensitivity analysis of performance parameters was carried out on the influence of the components parameters. The performance of mixed exhaust turbofan engine with PDC in the bypass duct was compared with that of the conventional afterburner turbofan engine at the same design circulation parameters. The results show that to increase the total pressure loss of isolator is beneficial to the improvement of performance because of the improvement of pressure ratio; when fan pressure ratio is constant, with the increasing of bypass ratio, the specific fuel consumption and specific thrust increase; with the increasing of fan pressure ratio, when bypass ratio is 0.2 to 0.4, specific thrust increases first and then decreases. When bypass ratio is 0.4 to 0.5, specific thrust increases first and then remains constant. When bypass ratio is 0.5 to 0.9, specific thrust increases, but the rate of increase reduces. At different bypass ratio, specific fuel consumption decreases with increasing of fan pressure ratio; the performance of engine is more sensitive to the component parameters that directly affect the flow state parameters of the bypass duct; because of supercharging performance of PDC, PDC in the bypass duct only uses part of air flow to organize combustion that can make specific thrust of turbofan engine with PDC in the bypass duct and conventional afterburner turbofan engine are equivalent. Meanwhile, specific fuel consumption can be reduced by 27.7% at design point and 12.8%-26.8% at off-design points.","PeriodicalId":515230,"journal":{"name":"Xibei Gongye Daxue Xuebao/Journal of Northwestern Polytechnical University","volume":"1114 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140467222","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}

{"title":"Optimizing and designing upper-stage separation spring of lifting-body rocket","authors":"Ji Miao, Xiaona Sun, Yanshou Luo, Jun AN","doi":"10.1051/jnwpu/20244210108","DOIUrl":"https://doi.org/10.1051/jnwpu/20244210108","url":null,"abstract":"Because the upper-stage separation of a lifting-body rocket is difficult under the low-altitude and high-speed flight environments, an upper-stage separation scheme based on the separation spring is proposed. The integration of ADAMS and MATLAB realizes the multi-body dynamics simulation analysis of upper-stage separation. The experimental design method is used to carry out the target simulation and calculation of the upper-stage separation process, with the separation condition deviation and the separation spring deviation considered at the same time, thus ensuring the reliability of the separation scheme. In order to further optimize the separation scheme, an upper-stage separation optimization model is established with the Isight software, and the mass of separation spring is optimized with the multi-island genetic algorithm and significantly reduced by 48.87% under the condition that the upper-stage separation process satisfies all constraints, thereby effectively improving the performance of the lifting-body rocket.","PeriodicalId":515230,"journal":{"name":"Xibei Gongye Daxue Xuebao/Journal of Northwestern Polytechnical University","volume":"68 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140463430","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}

{"title":"Study of GSO-GL based secondary source configuration optimization method for broadband sound field reproduction","authors":"Yidong Liu, Kean Chen, Jian Xu, Lei Yang","doi":"10.1051/jnwpu/20244210011","DOIUrl":"https://doi.org/10.1051/jnwpu/20244210011","url":null,"abstract":"Sound field reproduction is a method that uses multiple secondary sound sources to reproduce a predefined desired sound field in a listening area. The configuration of the secondary sound sources is a key factor affecting the reproduction performances. To optimize the secondary source configuration, this study proposes a new method that combines the Gram-Schmidt orthogonalization method with the group Lasso method, which is called GSO-GL method. Firstly, it selects a certain number of the secondary sources from all the alternative secondary sources using the Gram-Schmidt orthogonalization method. The excitation sources are then further selected from the secondary sources selected in the previous step using the group Lasso method. The sound field simulation from the 2D room model show that the GSO-GL method outperforms the Gram-Schmidt orthogonalization method or the group Lasso method alone, combining the high system stability of the Gram-Schmidt orthogonalization method with the high reproduction accuracy of the group Lasso method.","PeriodicalId":515230,"journal":{"name":"Xibei Gongye Daxue Xuebao/Journal of Northwestern Polytechnical University","volume":"56 ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140463910","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}

{"title":"Aircraft cabin lighting design method based on DIALux","authors":"Jinchi Fu, Dengkai Chen, Xian Zhang, Ning Xie","doi":"10.1051/jnwpu/20244210053","DOIUrl":"https://doi.org/10.1051/jnwpu/20244210053","url":null,"abstract":"Lighting in aircraft cabin is an important part of the aircraft interior lighting system. A reasonable cabin lighting design can improve the quality of flight services and enhance passenger satisfaction and comfort. In this paper, an aircraft cabin lighting design method is proposed based on the DIALux calculation and simulation software. Based on a quantitative evaluation, calibration and analysis of average illuminance, glare and uniformity of illuminance from the perspectives of travel safety, visual comfort and high quality service, the method explores and proposes an innovative approach to the design of aircraft cabin lighting. Finally, based on this method, an optical simulation model is established and visual simulation calculations are carried out to verify the feasibility of the method.","PeriodicalId":515230,"journal":{"name":"Xibei Gongye Daxue Xuebao/Journal of Northwestern Polytechnical University","volume":"230 ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140463081","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}

{"title":"Rocket landing guidance based on second-order Picard-Chebyshev-Newton type algorithm","authors":"Jingyuan Tang, Yongjie Gou, Yangyang Ma, Binfeng Pan","doi":"10.1051/jnwpu/20244210098","DOIUrl":"https://doi.org/10.1051/jnwpu/20244210098","url":null,"abstract":"This paper proposes a rocket substage vertical landing guidance method based on the second-order Picard-Chebyshev-Newton type algorithm. Firstly, the continuous-time dynamic equation is discretized based on the natural second-order Picard iteration formulation and the Chebyshev polynomial. Secondly, the landing problem that considers terminal constraints is transformed into a nonlinear least-squares problem with respect to the terminal constraint function and solved with the Gauss-Newton method. In addition, the projection method is introduced to the iteration process of the Gauss-Newton method to realize the inequality constraints of the thrust. Finally, the closed-loop strategy for rocket substage vertical landing guidance is proposed and the numerical simulations of the rocket vertical landing stage are carried out. The simulation results demonstrate that compared with the sequential convex optimization algorithm, the proposed algorithm has higher computational efficiency.","PeriodicalId":515230,"journal":{"name":"Xibei Gongye Daxue Xuebao/Journal of Northwestern Polytechnical University","volume":"44 ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140464113","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}

{"title":"Residence-times distribution function of a periodically modulated bistable system subject to noise recycling","authors":"Yazhen Wu, Zhongkui Sun","doi":"10.1051/jnwpu/20244210165","DOIUrl":"https://doi.org/10.1051/jnwpu/20244210165","url":null,"abstract":"The research mentioned in the statement focuses on investigating a theoretical method for calculating the residence-times distribution function (RTDF) in a periodically driven, bistable system subject to noise recycling. This situation deviates from a Markovian process due to the recycling lag, making it challenging to determine the RTDF using traditional two-state models. In this paper, the aim is to overcome this issue and provide a systematic analysis of how to calculate the RTDF in such a system. By considering the piecewise escape rate of the system, which relies not only on the current state but also on the previous state, we have successfully derived the recursive expression of RTDF. Then, RTDF for large and small A/D is approximately derived using a piecewise analysis formula, respectively. It is further demonstrated both theoretically and numerically that the RTDF has exhibited a feedback-induced structure as a result of the recycling procedure. The results are shown as follows: for large A/D, the RTDF exhibits a series of sharp peaks located at odd multiples of approximately half the period of the driving signal. This indicates the occurrence of stochastic resonance. Additionally, it is interesting to note that the RTDF displays a sharp dip at t=τ. It is further shown that the process of noise recycling increases the probability of short residence times for t < τ and decreases the probability of long residence times for t>τ. This demonstrates that noise recycling plays a crucial role in facilitating particle hops between the double-well potential. For small A/D, the RTDF displays a phenomenon of piecewise exponential decay and declines sharply at t=τ. Notably, the interval between discontinuities becomes smaller or even disappears with increasing the noise intensity or the relative strength. Furthermore, when driven by an appropriate periodic signal, the RTDF exhibits a sequence of maximum values at odd multiples of approximately half the period of the driving signal. However, these maximum values disappear with increasing the noise intensity or the relative strength. This suggests that moderate noise recycling can induce the occurrence of stochastic resonance. However, excessive noise recycling actually inhibits the generation of stochastic resonance. The theoretical results have been successfully validated via numerical methods, demonstrating the reasonability of the present theoretical approach.","PeriodicalId":515230,"journal":{"name":"Xibei Gongye Daxue Xuebao/Journal of Northwestern Polytechnical University","volume":"25 4","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140465519","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}

{"title":"Region optimization and sensitivity analysis of THT assembly process parameters based on flexible soldering robot platform","authors":"Tao Yu, Pan Zhao, Jikong Wang, Feiru Wang, Lei Wang, Guoliang Ma, Jing Hou","doi":"10.1051/jnwpu/20244210070","DOIUrl":"https://doi.org/10.1051/jnwpu/20244210070","url":null,"abstract":"In order to solve the problem that the selection of key process parameters of a flexible soldering robot depends on manual experience, the empirical model of its THT assembly process parameters is established with the response surface method and the reliability of the model is verified. On this basis, the multi-parameter relative sensitivity of the key process parameters is analyzed through the Monte-Carlo simulation, and their single-parameter sensitivity curve is drawn. Then, based on the sensitivity analysis, the stability region division method is designed, and the stability region of process parameters for soldering quality comprehensive score is obtained. The optimal region of process parameters of the soldering robot are acquired by compressing the stability region: soldering temperature from 350-368 ℃, soldering time from 1.31-1.48 s and solder feeding volume from 1.5-2.0 mm3. The average value of the soldering quality comprehensive score within the optimal region of process parameters is 90.2 points.","PeriodicalId":515230,"journal":{"name":"Xibei Gongye Daxue Xuebao/Journal of Northwestern Polytechnical University","volume":"46 9","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140465763","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}