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Research of line-of-sight angle on aero-optic imaging deviation for vehicles flying at 40—60 km

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Optoelectronics Letters 2023年第4期19卷 242-247页

作者： XU Liang ZHAO Shiwei WANG Tao Tianjin Key Laboratory of Complex Control Theory and Application School of Electronic Engineering and AutomationTianjin University of TechnologyTianjin 300384China Foreign Cooperation Projects Department PetroChina Dagang Oilfield CompanyTianjin 300280China

Aero-optical imaging deviation is a kind of optical effect,aiming at a conical aircraft.This paper analyzes the influence of the aircraft on the imaging deviation with the change of altitude and line-of-sight angle.In this paper,the relationships between imaging deviation and altitude as well as line-of-sight angle are analyzed,and the coupling relationship between altitude and line-of-sight angle is studied.We give the imaging deviation results of 5°—75°line-of-sight angle.The analysis shows that when the line-of-sight angle is in the range of 5°—35°,the imaging deviation is more sensitive,while the line-of-sight angle is in the range of 35°—75°,the imaging deviation is relatively flat,and the imaging deviation does not gradually decrease with the increase of line-of-sight angle,but there is a turning point in the middle of 5°—75°.The imaging deviation decreases first and then increases,and the turning point of line-of-sight angle is closely related to height.

关键词： deviation angle turning

Analysis of light propagation characteristic in the aero-optic flow field of cone-headed vehicle with side window

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Optoelectronics Letters 2024年第1期20卷 58-64页

作者： XU Liang ZHOU Liye WANG Luyang ZHAO Shiwei WANG Tao Tianjin Key Laboratory of Complex Control Theory and Application School of Electrical Engineering and AutomationTianjin University of TechnologyTianjin 300384China School of Intelligent Engineering Sun Yat-sen UniversityGuangzhou 510275China Southern Marine Science and Engineering Guangdong laboratory(Zhuhai) Zhuhai 519000China

Aero-optic imaging deviation research is carried out for infrared-guided vehicle with cone-head side window,with a focus on the propagation characteristics of light in an aero-optic flow field.When the light entering the aero-optic flow field from the free-stream should be close to the normal,numerous data indicate that the light is refracted away from the normal.This paper divides the aero-optic flow field into two parts and uses the gas density distribution in the aero-optic flow field to propose the hypothesis that there are two modes of refraction when light propagates through the flow field.The results show that light propagates from the optically denser medium to the optically thinner medium after passing through the shock wave and eventually leads to refraction away from the normal when the light enters the aero-optic flow field.

关键词： flow propagation light

Effect of radical scavenger on electrical tree in cross-linked polyethylene with large harmonic superimposed DC voltage

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High Voltage 2023年第4期8卷 739-748页

作者： Lewei Zhu Zhonglei Li Kai Hou Maritime College Tianjin Key Laboratory for Control Theory and Applications in Complicated Industry SystemsTianjin University of TechnologyTianjinChina key laboratory of Smart Grid of Ministry of Education School of Electrical and Information EngineeringTianjin UniversityTianjinChina

In this study,three kinds of radical scavenger Chimassorb 944,Tinuvin 622,and Tinuvin 770 are used to suppress the growth of electrical trees in cross-linked polyethylene(XLPE)with transient superimposed voltage under the temperature gradient.The tree morphology,tree length,accumulated damage,and time to breakdown are used to investigate the effect of radical scavenger on the electrical treeing process.It is found that under the temperature gradient caused by the temperature rise on the high voltage side,only Tinuvin 622 can always suppress the electrical tree as the temperature gradient rises.Under the temperature gradient caused by the temperature rise on the ground side,the three radical scavengers can all suppress the electrical tree.The breakdown of electrical tree exhibits the strong DC polarity dependence.Meanwhile,energy levels of these three radical scavengers are calculated through quantum chemistry,and the results indicate that radical scavengers have greater electron affinity,smaller ionisation energy,and smaller energy gap than XLPE.According to the surface potential decay test results at 60℃,it is found that all three radical scavengers can introduce deep traps.The different performances of radical scavengers under different temperature gradients and voltages are determined by the trap distribution characteristics,the molecular structure and chemical reaction of the additives themselves.It is concluded that Tinuvin 622 has potential for use in high voltage direct current XLPE cable application.

关键词： radical electrical harmonic

Simultaneous Location and Map Construction Based on RBPF-SLAM Algorithm

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Simultaneous Location and Map Construction Based on RBPF-SLA...

Investigation on Mesh and Sideband Vibrations of Helical Planetary Ring Gear Using Structure, Excitation and Deformation Symmetries

第30届中国控制与决策会议

作者： Hong He YunHui Jia Lei Sun School of Electrical and Electronic Engineering Tianjin University of Technology Tianjin Key Laboratory of Complex System Control Theory and Application

Solving the problem of simultaneous location and map construction（SLAM） is the core of robot autonomous navigation. At present, most algorithms usually only consider the odometer information of mobile robot, therefor, there exists some problems of increasing computation amount caused by a large number of sampling particles and the complexity. So, this paper developed a scheme of map construction and positioning based on RBPF-SLAM algorithm. The hardware and software platform is set up on the ROS, and it merge the odometer information of the robot into the distance information collected by the laser sensor, which effectively reduces the number of required particles and the uncertainty of the robot’s pose estimates in filter prediction phase. Through the experimental, get the conclusion: simultaneous positioning based on RBPF-SLAM algorithm and map construction system can create high-precision online raster map in real time, and it is more consistent with the actual map.

关键词： ROS RBPF-SLAM Algorithm Simultaneous Location Laser Sensor Pose Estimates

来源： cnki会议评论

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Chinese Journal of Mechanical Engineering 2018年第6期31卷 55-67页

作者： Shi-Yu Wang Chanannipat Meesap School of Mechanical Engineering Tianjin University 300072 Tianjin China key laboratory of Mechanism theory and Equipment Design of Ministry of Education Tianjin University tianjin key laboratory of Nonlinear Dynamics and control Tianjin University 300072 Tianjin China

Time?variant excitations in planetary gear trains can cause excessive noise and vibration and even damage the system on a permanent basis. This paper focuses on the elastic vibrations of a helical planetary ring gear subjected to mesh and planet?pass excitations. Motivated by the structure, excitation and deformation symmetries, this paper proposes dual?frequency superposition and modulation methods to capture the mesh and sideband vibrations. The transi?tion between ring gear tooth and planet is introduced to address the excitations and vibrations. The phasing e ect of ring gear tooth and planet on various deformations is formulated. The inherent connections between the two types of vibrations are identified. The vibrations share identical exciting rules and the wavenumber and modulating signal order both equal the linear combination of tooth and planet counts. The results cover in?plane bending and extensional, out?of?plane bending and torsional deformations. Main findings are verified by numerical calculation and comparisons with the open literature. The analytical expressions can be used to determine whether the sideband is caused by component fault or only by elastic vibration. The methods can be extended to other power?transmission systems because little restriction is imposed during the analysis.

关键词： Helical planetary ring gear Typical vibration modes Planet phasing Sideband

controlling the coal dust at transshipment point: A study of the foam-sol foaming device

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International Journal of Mining Science and Technology 2014年第5期24卷 625-630页

作者： Xi Zhilin Jiang Manman Sun Changping Tu Xian School of Environmental Science and Safety Engineering Tianjin University of Technology tianjin key laboratory for control theory & application in Complicated Systems Tianjin University of Technology School of Electrical Engineering Tianjin University of Technology

In order to effectively control the dust at the transshipment point with foam-sol, this paper attempted to study the characteristics of dust diffusion at transshipment point and the foam-sol foaming device with diffusion outlet was also designed in this paper. To study the diffusion rules of coal dust, fluent discrete phase model was utilized in the numerical simulation, as the coal dust was thrown down at a horizontal velocity of 2.5 m/s. A foam-sol foaming device was designed, through which foaming agent could be automatically sucked into the Venturi by the negative pressure. The automatic controller was also equipped,which could transform the energy of the compressed air into the constant pressure difference so that the gelling agent could be qualitatively added into the gel container. The diffusion outlet that could spray out foam-sol in a continuous, conical and 3D manner was also designed. Moreover, this paper also carried out the contrast experiments on dust removal efficiency among water, aqueous foam and foam-sol. The results clearly show that the symmetrical whirlpools appeared below the inlet where the largest whirlpool diameter was 0.52 m, and the horizontal distance from swirl range to the inlet was approximately0.69 m. By using the self-designed foaming device, the foaming was multiplied by 30 times and the volume ratio with water and foaming agent reached 95%:5%. In this context, the gas pressure was controlled at 0.3 MPa, with gas flow at 15 m3/h and water flow at 0.5 m3/h, with water pressure controlled between0.34 and 0.36 MPa. The foam-sol has the highest dust removal efficiency than other agents.

关键词：自动控制器发泡设备泡沫溶胶转运煤尘装置粉尘扩散

Research on Hybrid Scheduling Algorithm Based on CAN bus

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Instrumentation 2017年第2期4卷 22-27页

作者： HAN Shunyuan ZHANG Zhihong HE Hong School of Electrical and Electronic Engineering Tianjin University of TechnologyTianjin Key Laboratory of Complex System Control Theory and Application Transmission and Launch Department tianjin Radio and TV Station

In view of the problem that the packet information preempted netw ork resources in the process of transmission in the CAN bus,w hich leads to the low utilization of netw ork resources and the low accuracy of information transmission. Thus,a hybrid scheduling algorithm NM TS based on CAN bus is proposed,in the NM TS hybrid scheduling algorithm,the dynamic scheduling algorithm EDF is used to schedule hard real-time messages to solve the problem of low utilization of netw ork resources; the static scheduling algorithm RM S is used to schedule soft real-time messages and non real-time messages,so as to solve the problem of low accuracy of information transmission. By using M ATLAB softw are,the CAN netw ork model can be built,the EDF algorithm,RM S algorithm and NM TS algorithm are simulated. The experimental results show that the netw ork resources utilization is 90%,the packet loss rate is 0% of the NM TS algorithm. Therefore,The hybrid scheduling algorithm based on CAN bus NM TS has the characteristics of high netw ork resource utilization and high accuracy of information transmission,w hich w ill be very helpful for further research of CAN bus.

关键词： RMS EDF NMTS Hybrid Scheduling

A Method for Detecting Abnormality of CAN Bus in Vehicle

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Instrumentation 2017年第2期4卷 28-33页

作者： PENG Jing ZHANG Zhihong HE Hong School of Electrical and Electronic Engineering Tianjin University of TechnologyTianjin Key Laboratory of Complex System Control Theory and Application Transmission and Transmission Department tianjin Radio and Television Station

With the development of intelligent and netw orking technology in automobile,the malicious attacks against in-vehicle CAN netw orks are increasing day by day,and the problem of information safety in automobile is aggravated. In this regard,this paper analyzes the security loopholes and threats w hich the CAN bus faced,put forw ard a kind of anomaly detection algorithm for vehicle CAN bus. The method uses support vector machine algorithm to distinguish betw een normal message and abnormal message,so as to realize the CAN bus anomaly detection. Theoretical and experimental studies show that this method can effectively detect abnormal packets in the CAN bus w ith a detection rate of over 90%,w hich can effectively resist malicious attacks such as tampering and cheating on the vehicle CAN bus.

关键词： Automobile CAN bus Information Security Support Vector Machines Abnormal Detection

A multi-directional controllable multi-scroll conservative chaos generator:Modelling,analysis,and FPGA implementation

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Chinese Physics B 2021年第2期30卷 232-239页

作者：董恩增李荣昊杜升之 tianjin key laboratory for control theory&applications in Complicated Systems Tianjin University of TechnologyTianjin 300384China Department of Electrical Engineering Tshwane University of TechnologyPretoria 0001South Africa

Combing with the generalized Hamiltonian system theory,by introducing a special form of sinusoidal function,a class of n-dimensional(n=1,2,3)controllable multi-scroll conservative chaos with complicated dynamics is constructed.The dynamics characteristics including bifurcation behavior and coexistence of the system are analyzed in detail,the latter reveals abundant coexisting flows.Furthermore,the proposed system passes the NIST tests and has been implemented physically by FPGA.Compared to the multi-scroll dissipative chaos,the experimental portraits of the proposed system show better ergodicity,which have potential application value in secure communication and image encryption.

关键词： multi-directional controllable multi-scroll conservative chaos coexisting flows field programmable gate array(FPGA)