bluuebunny/crossref_metadata_2025 huggingface dataset:
Dynamic Modeling and Control Method of Dual-Body Satellite
Authors: Zhao Tongshuang , Zhang Jiyang , Wu Dengyun , Luo Ruizhi
Published: September 2021

For the attitude control problem of dual-body satellite with non-solid connection between payload module and platform module, this paper proposes a dual-body dynamics modeling and control method based on the concept of disturbance-free payload(DFP). The payload module is rotated in orbit with high precision, and its forces can be determined by performing a force analysis on it. The Euler equation is used to calculate the attitude information of the payload module, so that the motion of the payload module can be described more accurately. By designing the control algorithm and the control loop with the idea of DFP, the attitude accuracy of the payload module is better controlled. The simulation results show that the controller can keep the attitude accuracy of the payload module within “1.65”, the results meet the expectation.
Development of simulation platform for Automatic Storage production line
Authors: Wang Qinghua , Hu Yanhua , Fu Renxuan , He Junyong , Ma Xinzhou , Wang Jun
Published: September 2021

This paper develops a simulation platform of automatic storage production line based on 89C51 single chip microcomputer, which provides students with an interactive classroom learning and laboratory practical activities to assist the practical learning of industrial robot and programmable controller. The test shows that the transformation of the simulation code into the corresponding actual equipment is real, feasible, safe and reliable.
Engineering Optimization Method of Orbit Transfer Strategy for All-electric Propulsion Satellites
Authors: Han Mingren , Wang Yufeng
Published: September 2021

Nowadays, all-electric propulsion satellites have shown very good performance in missions such as geostationary communication and deep space exploration, and have been widely concerned by major aerospace companies around the world. Because the excellent performance of the electric thruster can enable the satellite to carry more payloads. While the use of electric thrusters for orbit transfer saves fuel consumption significantly, it also leads to the problem of long orbit transfer time. To solve this problem, a simplified low-thrust orbit transfer strategy is designed, which is simple in form, easy to store, while having few parameters to be optimized. In order to optimize the simplified transfer strategy, a bidirectional stochastic gradient descent method suitable for on-board calculation is proposed, with a simple algorithm process and small computation. It can be known from actual calculations that after 600 times of orbit extrapolation, it can converge to the optimal solution. Finally, we can draw a conclusion that the algorithm is feasible and effective by numerical simulation.
Simulation Experiment Analysis and Verification of Ship Resonance for Shipboard Helicopter
Authors: Zhu Yan , Lu Yuhui , Sun Fengnan , Cheng Qiyou , Wang Siwen , Li Zhenkun
Published: September 2021

According to the dynamic characteristics of shipboard helicopter landing, the time-domain load of ship movement on the fuselage under complex sea conditions, the nonlinear dynamic characteristics of rotor damper, and the influence of rotor blade flapping movement and aerodynamic force are considered. The fuselage, rotor lagging damper, blade flapping and lagging movement and aerodynamic model are modeled separately as sub-models, and then the subsystems are integrated according to mechanical principles to finally establish the ship resonance analysis model of helicopter. The method for simulation experiment of ship resonance is put forward. The whole process of ship resonance experiment is dynamically demonstrated by digital simulation technology, which simulates the excitation load on the fuselage caused by the rise and fall and rolling movement of the ship. Actually simulates the lifting collective pitch and conducts periodic excitation by disturbing the control stick. Based on the transient response of the time-domain simulation dynamic system under disturbance, the stability of ship resonance is analyzed. The accuracy of the simulation method is verified through project cases, and the simulation experiment analysis techniques for accurately predicting the unstable boundary of ship resonance are mastered, which provides design and analysis means instead of the experiment that cannot be carried out in model development.
Analysis on reducing eddy current loss of axial motor by permanent magnet segmentation
Authors: Bu Yuhang , Wang Aiyuan , Qin Yifei
Published: September 2021

This paper gives the causes of eddy current loss of permanent magnet in axial permanent magnet motor, and puts forward the method of reducing eddy current loss by circumferential and radial combined sectional insulation of permanent magnet. The principle analysis and analytical formula derivation of permanent magnet sectional insulation to reduce eddy current loss are carried out. Finally, Maxwell three-dimensional finite element simulation is used to verify that the circumferential and radial combined sectional insulation of permanent magnet can greatly and quickly reduce the eddy current loss of permanent magnet of axial motor.
Fingertip blood sampling robot navigation system based on binocular vision
Authors: Li Xi , Ji Jiajia , Zhou Qin
Published: September 2021

In the fingertip intelligent blood collection robot, we need to move the blood collection needle to the designated position quickly and accurately, but it is difficult to meet the two indicators of speed and accuracy at the same time. This paper proposes a fast navigation method based on binocular vision. This method obtains the coordinates of the fingertip blood sampling point through three-dimensional reconstruction and contour extraction, and guides the robotic arm to quickly move the blood sampling needle to a position near the blood sampling point according to the coordinate position. The method in this paper is used for the rough navigation of blood collection robots, and it is verified by experiments that this method can meet the needs of blood collection robots.
Air ionizers case study
Authors: Qian Cheng
Published: September 2021

Fresh air is essential for humans’ physical and mental health, and it helps us relaxed and relieve stress. Air ionizers can remove harmful gases in the air and absorb suspended particles in the air, especially various bacteria and viruses. This report investigates the nature and working principles of air ionizers and discusses their application in the indoor environment and the protection of human exposure. We used the ozone emission test, particle removal rate and clean air delivery rate to analyze the effectiveness of four selected air ionizers. Simultaneously, this report identifies the side effects of air ionizers and advice more further studies about air ionizers before promoting them into daily-life use.
High Accuracy Attitude Controlling of Vehicles for launching According to Deformation Reconstruction
Authors: Liang Zhuang , Zhang Yulin
Published: September 2021

To solve the problem that the curvature information of the large flexible rocket body affects the attitude controlling for rocket body, the present study proposes an attitude controlling approach by complying with reconstruction for deformation, which can realize the highly precise attitude controlling of the large flexible vehicle for launching. Firstly, the deformation parameters of the rocket were obtained by using the fiber grating sensing device. Then, the deformation information and attitude information were introduced into the increment-based dynamic inversing control loop at the same time, and the attitude controlling framework containing the deformation information of the rocket was established. Finally, the results achieved based on the simulation show that for flexible vehicles for launching with obvious vibration and deformation, this approach can compensate the faults attributed to elastic deformation and improve the accuracy and stability of attitude control.
Study on dynamic characteristics of bearing-rotor system under ship sway condition
Authors: Ding Kongxing , Zhu Faxin , Yang Qijiang , Teng Xianbin , Chen Wenxiang , Wang Zhaojian , Zhang Xiao
Published: September 2021

On condition that pans and tilts, ship bearing rotor system stability and security, as the change of ship swaying amplitude have influence, based on independent research and development of guangzhou maritime college design of vertical and horizontal swing test bench, simulate the real working condition of ships at sea, in the performance of bearing rotor system under rolling condition were studied. LMS_TEST. LAB modal tester software was used to analyze the dynamic characteristics and collect the experimental data of the bearing rotor system for analysis and research. In this paper, the influence of period and amplitude on the dynamic characteristics of the bearing-rotor system and the influence on the axis trajectory of the bearing-rotor system under different working conditions are analyzed mainly under the rolling condition.
Study on image quality Control Method based on Gaussian Noise
Authors: Ding Chao , Zhang Minghu , Gu Yi
Published: September 2021

At present, various image quality evaluation algorithms emerge in endlessly. The establishment of these algorithms, the performance evaluation of the system and the accuracy of evaluation results all need to be based on images of different quality as reference standards. This paper selects the peak signal-to-noise ratio as the characteristic parameter to measure whether the image quality changes, and uses the control image quality parameter to control the image quality. The experimental results show that the model can quickly and accurately obtain a large number of images with different distortion degrees, and control the image quality.
Study on Calibration Method for Testing During Burn In equipment of integrated circuits
Authors: Sun Chongjun , Ding Chao
Published: September 2021

In order to implement Method 1015 of GJB 548B, TDBI(Testing During Burn In) technology of integrated circuit is widely used in the aging process of core VLSI(Very Large Scale Integration) which is included of FPGA, DSP, CPU and dedicated chips. Many models of TDBI equipment at home or abroad have been come into use. It is an important task to calibrate TDBI equipment in system level and ensure the traceability of its measurement value. At present, the calibration device of TDBI equipment has been successfully finalized and put into production, which has the advantages of convenient use and high cost performance. This paper mainly introduces the calibration method for TDBI equipment of integrated circuit from the aspects of the overall architecture design, signal adaptation design and calibration software design.
Design and manufacture of customized products based on 3D printing technology
Authors: Yang Bingguang
Published: September 2021

3D printing technology, as a new manufacturing technology, has attracted more and more people’s attention, and the application field is more and more wide. 3D printing technology has broken the limitations of traditional manufacturing process and brought great advantages to the design and manufacture of customized products. This paper analyzes the current situation of private customized products, the principle and manufacturing process of 3D printing technology, the design method and manufacturing process of private customized products, and the application of 3D printing technology in the design and manufacturing of private customized products, and gives some opinions, hoping that 3D printing technology can better serve the design and manufacturing field of private customized products and promote it.
Design and finite element analysis of longitudinal vibrating stepped ultrasonic horn
Authors: Zhao J T , Ning L P , Jiang Z M , Li Y L
Published: September 2021

In this paper, a longitudinal vibration stepped ultrasonic horn was designed, and the size parameters of the ultrasonic horn were designed by theoretical calculation. In order to verify the rationality of the ultrasonic horn design, the finite element analysis software was used to perform a modal analysis on the horn, and the vibration mode and natural frequency of the ultrasonic horn within the design frequency range were obtained. The modal analysis results show that the natural frequency of the longitudinal vibration of the horn had a large error from the design frequency. Therefore, the size of the horn was optimized to make the natural frequency of the ultrasonic horn conform to the design frequency requirements. In addition, the optimized ultrasonic horn reduces the maximum stress which improves the safety and service life of the horn.
Application of Flow Field Analysis in the Process Design of Modified Microporous Aeration Oxidation Ditch
Authors: Xu Haodong , Qiu Yan , Yang Wei , Li Hai
Published: September 2021

According to the environment and water quality factors of the project location, an improved microporous aeration oxidation ditch process is designed, which has the characteristics of biochemical reaction of space division, microporous aeration, infinite water circulation in the ditch, and multiple water inlets; under simplified boundary conditions, based on the CFD method, the SSTK-W model is used to close the RANS equation to simulate the flow field in the hypoxic and aerobic areas. With the optimal equipment configuration and the lowest energy consumption, the flow velocity in the trench is more than 0.3m/s, to ensure high buffering capacity of the process; study the flow field state and the unfavorable flow velocity under the optimized operation state of the flow thruster; the rationality of the design is verified through the commissioning and operation of the sewage treatment plant.
Research on the relationship between workpiece surface machining quality and turning tool wear
Authors: Cao Min , Zhou Chen , Li KaiMing
Published: September 2021

In order to apply the workpiece surface machining quality detection data to tool wear prediction, an experiment on the relationship between workpiece surface machining quality and turning tool wear was carried out. Firstly, the experimental parameters are selected, and the workpiece surface quality is determined as the parameter to study the tool wear law; Secondly, by changing the tool material and workpiece material, the change law of tool wear is analyzed, and the internal reason of blade initial wear is revealed; Finally, the relationship between workpiece surface machining quality and tool wear is analyzed by measuring workpiece surface machining quality parameters. The experimental results show that the relative hardness of workpiece material and tool is the main factor determining the wear speed of tool flank, and the tool geometry is the main factor of rapid tool wear in the initial stage. The workpiece surface roughness increases gradually with tool wear. When the tool enters the severe wear stage, it decreases slightly and then continues to increase. The outer diameter of the workpiece decreases with the tool wear in the initial stage, and then fluctuates and increases gradually. The influence of tool wear on the cylindricity error of shaft parts can be ignored.
A Blade Dynamic Strain Inversion Method for Rotating Blades Based on Blade Tip Timing
Authors: Guo Haonan , Yang Yongmin , Guan Fengjiao , Hu Haifeng , Shen Guoji , Bian Zifang , Teng Guangrong
Published: September 2021

Based on the vibration response transfer ratio and Natural Neighbor Interpolation (NNI), the research on the noncontact inversion method of dynamic strain of high-speed rotating blades is carried out. The high-speed rotating blade is analyzed through the motion equation, and the correction method of the transfer ratio is proposed through NNI. The three-dimensional model of the rotating blade is established, and the Finite Element Analysis (FEA) considering stress stiffening is carried out to obtain the transfer ratio between the blade tip displacement and the blade strain at a certain speed. The vibration experiment of the high-speed rotating blade is carried out, and the blade tip displacement and the dynamic strain of the key points of the blade are obtained based on Blade Tip Timing (BTT) and strain gauges. The experimental data are processed to obtain the actual transfer ratio of the key points of the blade, and the theoretical transfer ratio is corrected based on NNI. The results show that when the 1st-order resonance of the rotating blade occurs at the rotating speed of 7960RPM, the strain inversion error of the test point can be reduced to less than 5%, which verifies the proposed correction method. Therefore, the blade dynamic strain can be inverted more accurately based on BTT.
Design of humidifier test system for proton exchange membrane fuel cell
Authors: Wang Xu , Li Hongshuang , Yin Ruoyu , Li Chenglong
Published: September 2021

Humidifiers are often used in the system of fuel cells to ensure the continuous and stable working operation. In order to evaluate the performance of the same humidifier under different operating conditions, this paper proposes a test system for proton exchange membrane fuel cell humidifier (PEMFC). In this paper, the study factor is gas flow rate. During the test process, the system simulates the working condition of the humidifier in the fuel cell system, and measures the dry-and-wet bulb temperature and the pressure flow at the outlet of the dry side of the humidifier with different gas flow rate. Finally, calculated relative humidity, determines the water permeability of the humidifier membrane. And the main factors affecting the humidification effect of the humidifier was analysed. According to the test results, compared with the relative mass transfer time, heat transfer has more effect on the humidification effect.
Design of Intelligent Security Early warning system for unguarded railway crossing in mining area
Authors: Zhu Shilin , Meng Xiangzhong
Published: September 2021

There are many railway crossings in the mine, but there are not enough people to keep every crossing manned. For the traditional unguarded railway crossing, we set up a warning sign at a certain distance from the crossing to remind pedestrians and drivers. For some crossings with poor vision, both pedestrians and locomotive drivers at the crossings can’t make timely and accurate judgment on the surrounding real-time road conditions, which is easy to cause safety accidents. In order to solve this technical problem and demand, an intelligent security and early warning robot with image recognition module and intelligent control board was developed by combining advanced theories and technologies such as Internet +, image recognition, beidou+ GPS dual-mode positioning, wind and solar complementary power generation and multi-sensor fusion. The system can improve the intelligent level of the unguarded crossing in the mining area, realize the unmanned or less unmanned crossing work, and ensure the safety of railway transportation in the coal mine.
The load sharing structure design and FE analysis of planetary gearbox with flexible pin
Authors: Yin Huabing , Tang Pei , Zhou Ruyi , Xing Qinkun
Published: September 2021

The paper first introduced the unequally load sharing in the planetary gear set and explained the cause of unequally load sharing in traditional design. Then a new floating structure of planetary gear with flexible pin has been designed to improve unequally load sharing of planetary gear set. In order to verify the flexible pin structure effects on the load sharing, two integrated finite element models have been built. Each one consists of two coupled planetary gear sets. One finite element model has been built with flexible pin structure and the other with fixed pin. The same load and boundary conditions have been applied to the two different finite element models. After analysis, the vonmises stresses of different parts such as ring gear, planetary gear, bearing and pin etc. in two different models have been compared. From the analysis result verification, the maximum vonmises stress of flexible pin of planetary gear set is much higher than that of planetary gear set with fixed pin in different mesh position. Although it is in the design range of material strength, its increase indicates that flexible pin structure makes the higher unequal mesh load of planetary gear shared with other pinions, the deflection of flexible pin make the load sharing with other pinions possible. Whereas the maximum vonmises stresses of other parts such as ring gear, planetary gear, bearing and sun gear decreases in a certain degree with the flexible pin deflection. It really indicates that the effect of flexible pin in the planetary gear set is obvious against fixed pin. When the higher unequally sharing load becomes smaller, maximum vonmises stresses of all planetary gear set parts except flexible pin become smaller and safer.
The Computer Numerical Control System Design for the Saddle Surface of the Flange Connection Processing Plant
Authors: Qian Ruiwei , Feng Yan , Ren Yongfeng , Yang Dongfang
Published: September 2021

It is required to construct huge hydrocracking units in order to boost the revenue from refined goods. The barrel welding receiver skirt has a saddle-shaped surface in the reactor processing of the barrel welding receiver skirt, and the processing process is getting increasingly complex. In order to enhance the welding quality of the skirt to the actual form of the receiver as the size and wall thickness of the receiver grow, it is important to develop the CNC system for welding the skirt to the actual shape of receiver. It talked about the manufacturing plan, the hardware circuit, and the software flowchart, to name a few subjects. Finally, the C programming language and the assembles programming language are utilized to implement the manufacturing flowchart in uVision3. Protues8 is responsible for the implementation of the hardware circuit. It is demonstrated by the simulation results that the proposed design plan for the CNC system is technically possible.
Design and application of water gun for pre-cleaning exposure footwear and helmet
Authors: Xia Jianjun , Wang Hongyang , Bao Zhiming , Jing Lishuai
Published: September 2021

The hard equipment of exposure footwear and helmet should be cleaned thoroughly to keep firefighter’s healthy. To balance the relationship between effective removing of contamination and equipment’s well preserved, new water gun with suitable air pressure was studied. Firstly, the water gun containing flow stabilizer part, venturi part and jet-flow part was designed for pre-cleaning step. Secondly, the contaminating and cleaning experiments were carried out by introducing new water gun. Thirdly, the result data was analyzed using histogram graph and the conclusions were obtained. This new water gun for pre-cleaning could remove contamination like mud effectively avoiding any damage. Further study should focus on removing the hard equipment’s oil stain in the washing step.
Research and application of double-row steel sheet pile stability in soft soil foundation
Authors: Huang Chao-xuan , Liu Yue , Yao Zhi-wei , Li Jun-jie , Xia Yong
Published: September 2021

In view of the complex stability calculation of double-row steel sheet piles in soft soil foundation, based on the theory of soil mechanics, the control analysis was carried out from the aspects of anti-uplift stability, overall anti-slip stability, anti-overturning stability, and overall sliding stability of the sheet pile. By theoretical derivation and calculation, the calculation formula of the minimum penetration depth Ld of steel sheet piles is given. Taking the double-row steel sheet pile cofferdam project of the sluice of the Oufei Reclamation Project in Zhejiang Province of China as a case, according to the formula in this paper, the recommended minimum depth of soil penetration is 17.01m, which is basically the same as the actual design value of 18.50m. Combined with the finite element soft foundation, the comparative analysis of simulation calculation results and the measured horizontal displacement monitoring data of steel sheet piles provides references for related engineering applications.
The Influence of Surface Texture on Tribological Characteristics of Water-lubricated Rubber Bearing
Authors: Wang Huanjie , Liu Zhenglin
Published: September 2021

To study the effect of surface texture on the tribological characteristics of ship’s water-lubricated rubber bearings, the surface texture modification technology is applied to the friction surface of the lining, and the tribological characteristics of the surface texture are studied. The tribological characteristics of the flow field, such as velocity change, water film pressure distribution, and the influence of water film thickness on the surface texture flow field were discussed by simulation analysis. The results show that the average velocity is decreased on the texture surface, and the water film pressure obtained by the inclined cylinder pitted surface texture is the least.
Design and study of new riser dynamic load compensation device test system
Authors: Wang Zhikun , Zhang Yanting , Wang Ruifeng , Huang Lumeng
Published: September 2021

To ensure the safety of the riser, a kind of new riser dynamic load compensation device is used in this paper, which can effectively reduce the dynamic load of the riser. At the same time, according to a certain similarity criterion, the riser dynamic load compensation test system was designed, including heave simulation system, load simulation system and compensation system. The co-simulation model of the system was established by using ADAMS and Simulink, and the effects of accumulator volume, precharge pressure, piston rod area of compensating hydraulic cylinder and throttle time constant on the system performance were analyzed. The simulation results show that the dynamic load compensation device has a certain compensation effect.
Research on Energy Efficiency Design Index Calculation Method for the Hybrid Ship
Authors: Wang Zhifang , Yang Zixuan , Xiao Shuming
Published: September 2021

The Marine Energy Efficiency Design Index (EEDI) is recognized as an effective tool to measure the level of carbon emissions from ships at home and abroad. It will play an important role in the assessment of carbon emissions from the shipping industry, especially under the current and future development goal of carbon neutrality. Various green technologies to reduce the carbon emissions of ships have been demonstrated and applied. Hybrid power system is one of them. Compared with traditional direct propulsion, it can significantly reduce the energy consumption and carbon emissions of ships in inland waters such as the Yangtze River. Based on the characteristics of the hybrid power system, this paper firstly analyzes the power types of the hybrid power system during ship navigation. Then, according to the principle and elements of EEDI calculation method, it puts forward the key problems that should be solved in ship EEDI calculation of hybrid power system. Then, according to different hybrid operation modes, it also puts forward the calculation method of EEDI of each power mode and the calculation method of acquired EEDI of hybrid ship. Finally, the calculation and analysis of a 7500DWT hybrid bulk carrier show that the EEDI calculation method for hybrid ships proposed in this paper is scientific and reasonable.
Semi-Adaptable Human Hand Motion Prediction Based on Neural Networks and Kalman Filter
Authors: Wang Juxing , Shen Linyong
Published: September 2021

This paper focuses on predicting trajectories of the human hand in order to improve the safety for human-robot interactions. In this work, the position and orientation are represented by two curves in the operation space such that the same algorithm can be used for both position and orientation prediction. The motion prediction is achieved in two steps. Firstly, the neural network (NN) model is applied for offline training to model the human hand motion. Secondly, the Kalman filter is added to adjust the weight coefficients of the NN model’s output layer online when a set of new data is measured, such that the NN model is adaptive to new data. An experiment study has been conducted to validate the effectiveness of the proposed algorithm. The result shows that the proposed algorithm achieves a higher prediction accuracy and requires a smaller amount of data to achieve optimal performance compared with the advanced method.
Research on YOLOv3 target detection model in the field of remote sensing
Authors: Yang Yao , Huang Cong , Wang Huajun , Wan Jun , Wang ZhenHeng , Ma Yu
Published: September 2021

The target recognition problem of high-resolution remote sensing images is marine traffic monitoring, disaster reduction emergency search and rescue, unmanned autonomous systems (UAS) (such as unmanned aerial vehicles, unmanned vehicles, unmanned submersibles, unmanned surface craft and other autonomous robots) and other civilian applications. The core technology of the system is also the key technology of military automatic target recognition (ATR) systems such as military reconnaissance, precision guidance, and maritime monitoring. With the development of high-resolution earth observation systems, more and more industrial applications require the extraction of more valuable target details from high-resolution remote sensing images. Then, due to the complex background of high-resolution remote sensing images and the difference in image quality (factors such as size, resolution, noise, etc.), low target detection accuracy and slow speed are the main bottlenecks that affect the combination of artificial intelligence and remote sensing. In order to solve the technical bottleneck of target detection, this paper focuses on exploring the detection performance of the channel attention module SElayer and YOLOv3 model in the field of high-resolution remote sensing images, providing basic technical support for related research.
A Lightweight Private Internet of Things Remote System and its Micromixing Application
Authors: Fu Hai , Yang Tianhang , Jia Weiliang , Li Songjing
Published: September 2021

Most current Internet of Things systems face many problems like privacy leakage, information island and low application value, because they are designed from the perspective of Internet of Things service providers. However, the practicality and privacy security of Internet of Things services are more important from the perspective of Internet of Things system users. Considering that there aren’t too many Internet of Things devices to use and manage for ordinary people and service, a more service-oriented architecture of the lightweight private IOT remote system is proposed in this paper. To verify this system, verifications like remote sensors, remote actuators, and a micromixing application are developed and illustrated. Owing to its distributed server architecture, this system has high flexibility, practicability, parallelism, and low coupling. This novel system architecture provides a new perspective to develop practical valuable private Internet of Things services.
Design and implementation of face recognition system based on convolutional neural network
Authors: Ma Yu , Wang HuaJun , Wan Jun , Wang ZhenHeng , Yang Yao , Huang Cong
Published: September 2021

The main features of face recognition are easy to use, quick to update, high flexibility, high accuracy, high environmental adaptability and so on. This passage of facial recognition technology based on convolutional neural network, which combines the present popular Python and Opencv Keras to identify development system, will make face recognition more efficient and more intelligent. And convolutional neural network based on face recognition data can improve accuracy and reduce the error rate through training. This experiment makes efforts to perfect the training model and enhance the influence of face recognition, so it could be more influential and smarter in higher precision applicable areas.
Fast Path Planning for Firefighting UAV Based on A-Star algorithm
Authors: Gao Jianfeng , Zheng Yu , Ni Kai , Mei Qiliang , Hao Bin , Zheng Long
Published: September 2021

When the long distance oil-gas pipeline accident occurs, the fire UAV can give priority to the place where the accident occurs. Emergency investigation and fire rescue, greatly reduces the harm of the accident. However, due to the limitation of the UAV navigation system, the UAV will accumulate the positioning errors over time in the flight process. If the positioning errors can not be corrected in time, it will make the UAV unable to reach the intended destination, thus leading to the failure of the rescue mission. In view of this phenomenon, we propose a UAV path planning scheme considering positioning errors. Taking the UAV’s total flight path as short as possible and errors correction points as few as possible, a multi-objective programming model is established considering errors correction constraints and path constraints. The Euler distance with coefficient is selected as the estimated cost function of A-Star algorithm, and the optimal flight path of UAV is quickly planned through heuristic search. Taking the data of a certain flight area as an example, we have simulation results showing that the A-Star algorithm can quickly and effectively solve the problem of UAV flight path planning considering positioning errors.
A Novel Approach of Interface Stiffness Identification Based on Wave Propagation Method
Authors: Yuan Bo , Mu Xiaokai , Wang Yunlong , Zhang Chao , Sun Qingchao , Sun Wei
Published: September 2021

The contact joint in mechanical system will bring uncertainty, which leads to the uncertainty of dynamic response. Identification of interface stiffness is particularly important in the assembly process, such as bolt connection and rivet connection. In this paper, the contact joint can be regarded as a kind of structural discontinuity, and the contact joint in two beams is modeling with shear stiffness and bending stiffness. The wave theory is integrated into the Euler-Bernoulli beam theory to establish the relationship between the power reflection coefficient and the interface stiffness. The proposed method is verified by establishing a finite element model. The results show that the interface stiffness is accurately identified. In addition, the influence of interface stiffness on power reflection coefficient is discussed. This method has better local characteristics and avoids the disadvantages of identification by natural frequency method.
Knowledge graph based System model configuration design
Authors: Fu Chao , Liu Jihong , Zhang Longxi , Mao Yinxuan , Jin Jie
Published: September 2021

When solving the complexity problem between different fields, traditional document-based system engineering (TSE) is difficult to meet current research and development needs, and model-based system engineering (MBSE) is the best choice. With the implementation and application of MBSE in enterprises, the system model files are gradually accumulated. Therefore, this paper studies the reusability of the system model and builds the system model knowledge graph to achieve efficient reuse of the existing system model. A product configuration method based on subgraph matching is proposed and by configuring the product, the designer can obtain more feasible solutions, and then get the best design solution. Finally, an example of remote sensing satellite design is given to verify the effectiveness of the method.
Research on Fast Estimation Method of Fuzzy Parameters for Motion Blurred Images
Authors: Luo Jinhui , Bo Tao
Published: September 2021

Motion blur distortion is the most common type of image distortion in daily life. the research on motion-blurred image restoration technology has developed more mature. Classical algorithms such as Wiener filter and Kalman filter and various improved algorithms can achieve better results, but they take a long time and have great limitations in actual image restoration application scenarios. To solve this problem, this paper proposes an algorithm for fast restoration of image motion blur, an improved algorithm based on Randon transform to judge the image motion blur angle, and studies the algorithm for estimating the blur length under the condition that the blur angle is determined, and obtains two motion blur parameters of blurred image. Experimental results show that the fast image restoration method proposed in this paper has shorter time consumption, stronger anti-noise interference ability and better practicability.
Research on the influence mechanism of assembly stress on reliability of space deployable mechanism
Authors: Zeng Ting , Wang Huaiming , Chen Lihui , Li Yun
Published: September 2021

The on-orbit performance of spaceborne SAR satellite mainly depends on the unwrapping precision of antenna panel, which is determined by its supporting pole system. The assembly stress of the pole system affects the antenna deployable precision in the assembly process of SAR antenna deployable mechanism. Aiming at this problem, this work presents a efficient method that the three-dimensional model of the deployment mechanism of SAR antenna is established, and the method of finite element simulation analysis is adopted. Prestress is applied to the pole system to simulate its assembly stress, and then we study the deformation law of the antenna panel under different assembly stress combinations of the mast system, and the mapping relationship is determined between the mast system and the flatness of the antenna panel. The most sensitive pole affected by the antenna panel deformation is obtained. The results show that the flatness of the antenna panel is related to the dimensional tolerance and position of the pole system, especially Large dimensional tolerance results in large deformation of antenna panel. In addition, the deformation area of antenna panel is determined by the assembly stress of different pole combinations. According to this research, it is concluded that the poles which should be controlled are obtained in the assembly process of the antenna deployable mechanism, which lays a theoretical foundation for the high precision assembly of the truss space deployable mechanism.
Finite Element Analysis for the High Pressure Rotary Cylinder Block
Authors: Tu Gongyi , Li Jianguo , Jiang Yanling , Zhang Xiancheng
Published: September 2021

As a pneumatic actuator, high pressure rotary cylinder has been successfully used in some ships, which can provide large torque output and is small and easy to install. The finite element method is used to calculate the cylinder block of high pressure rotary cylinder, and the stress and deformation of the cylinder block are analyzed by using the real stress-strain curve of metal materials. The distribution of stress and deformation is obtained. Moreover, the influence of 1 ~ 7MPa gas pressure on stress and deformation of the cylinder block is investigated. The maximum stress and deformation of the cylinder block under different pressure loads are obtained. The analysis results provide a basis for the design and operation of high pressure rotary cylinder.
Preparation and properties of magnesium oxysulfide inorganic microwave absorbing coating
Authors: Zhao Xu , Hao Wanjun , Zhao Feng , He Nan
Published: September 2021

This paper mainly introduces the harm of electromagnetic radiation pollution, and based on the electromagnetic wave absorption theory, the microwave absorption performance of single-layer microwave absorbing coating with magnesium oxysulfide cementitious material as matrix material and iron tailings as microwave absorbing agent is studied. The experimental results show that the absorbing effect of the absorbing coating mixed with 0.5 proportion iron tailings is the best, and the absorbing performance increases obviously with the increase of thickness. The maximum absorption value of 3mm thick coating sample is - 6.0 dB. The prepared microwave absorbing coating has certain application value in electromagnetic protection.
Research on path Planning algorithm of Unmanned ship in narrow Water area
Authors: Sun Liang , Zhao Yue-lin , Zhang Jian
Published: September 2021

Aiming at the problems of strong random search characteristics and high volatility of planning path in bi-directional Rapidly-exploring Random Tree (bi-RRT) algorithm, a new random tree growth strategy is proposed, the connection between random trees is improved to improve the path-finding speed of the algorithm, and the improved bi-RRT algorithm is used to design a path planning algorithm for unmanned ships in narrow waters. At the end of this paper, the unmanned ship path planning experiment in the island and reef area is carried out, and the experimental results show that the unmanned ship path planning algorithm based on the improved bi-RRT algorithm can quickly provide a safe path for the unmanned ship in narrow waters, and has advantages over the traditional bi-RRT algorithm in terms of time performance, planning path length and volatility, which can provide relevant reference for the research of unmanned ship intelligent navigation.
Research on Electronic Bill of Lading of Container Shipping Based on Blockchain Technology
Authors: Shi Hankun , Wang Xuelin
Published: September 2021

This paper analyzes the electronic bill of lading technology of container shipping, and solves the key problems such as the loss of bill of lading during the circulation of paper bill of lading. Based on the optimization of the basic structure and core technology of electronic bill of lading, this study incorporates the blockchain technology, analyzes the fit between blockchain technology and electronic bill of lading, and constructs a new model of electronic bill of lading for container shipping based on blockchain technology, which improves the safety and stability of shipping transaction information and provides more effective solutions for the future practice of electronic bill of lading for container terminals.
An image reconstruction algorithm based on classified block
Authors: Zhang Yuanwei
Published: September 2021

This paper constructs a compression image reconstruction algorithm(ABCS-MMSE). ABCS-MMSE overcomes the defects of compression sensing sampling. It not only constructs the block measurement matrix at encoding end but also generates the block recovery matrix at decoding end. Experimental results show that the average reconstruction time of ABCS-MMSE is much lower than that of BCS-SPL-DDWT and that of BCS-SPL-DCT. At the same time, for the images with smooth information, the reconstruction quality of ABCS-MMSE is not much worse than that of BCS-SPL-DDWT and that of BCS-SPL-DCT.
A comparison of parameters optimized-type VMD methods used in bearing fault diagnosis
Authors: Xu Wang , Hu Jinfei
Published: September 2021

In the early fault stage of bearings, the impact component of the signal is easily submerged by strong noise. To solve this problem, some fault diagnosis methods have been developed based on the variational mode decomposition (VMD) with optimized parameters. In this paper, we compare the performance of three different VMD methods with parameters optimized by whale optimization algorithm (WOA), grey wolf optimization (GWO) and particle swarm optimization (PSO), respectively. The results show that under the same conditions, the performance of WOA-VMD is better than that of the other two optimized VMD methods.
Safety monitoring method of vehicle bridge stress structure based on wireless sensing technology
Authors: Lian Depan
Published: September 2021

In the safety monitoring of bridge stress structure, the influence of surrounding environment and noise interference will cause the change of monitoring node coverage and affect the monitoring accuracy. Based on wireless sensor technology, a safety monitoring method of vehicle bridge stress structure is proposed. The interpolation fitting method is used to calculate the stress value of the sensor, and the optimal layout of the sensor is determined with the minimum deflection transfer error as the objective function. Probability sensing model is used to establish wireless overlay network, and wireless sensing technology is used to collect monitoring data. Based on the monitoring data, the static and dynamic response equation is established to establish the finite element model of bridge stress structure. The first level early warning threshold is determined according to the monitoring data under the normal operation state of the bridge, and the second level early warning threshold is determined according to the most unfavorable load distribution of the finite element model, so as to complete the bridge safety monitoring. The experimental results show that the average deformation deviation of the monitoring method proposed in this paper is 0.26mm, which is 0.77mm and 1.22mm smaller than the monitoring methods based on machine vision and GPS differential positioning technology, indicating that the monitoring method in this paper is more accurate and meets the safety requirements of bridge engineering.
Modal and structural defect analysis for a new docking mechanism
Authors: Lan Weibin , Fan Shouwen
Published: September 2021

In medium or small-sized spacecrafts’ docking process, it’s feasible to adopt a flexible probe for the probe-cone docking mechanism instead a buffer to reduce the docking impact force. The governing equations of kinematics and dynamics are derived from Lagrange analytical method. The influence parameters of the impact force are separated by simplifying the impact mathematical modeling. The effects of the influence parameters in the impact force, such as the length of docking beam, and the material of the docking mechanism, are discussed by finite element method. The varation amplitude and varation frequency are obtained by docking experiment, and reliability and correctness of the analysis reuslts are verified.
Research on the New Type of Error Detection Platform for Photoelectric Encoder
Authors: Li Kun , Cao Guohua , Ding Hongchang , Hou Han
Published: September 2021

In order to realize the error detection of high precision optical encoder, an error detection method of optical encoder based on optical continuous closed loop (OCCL) was proposed, by the principle of small angle measurement of photoelectric autocollimator and single reflector. Firstly, the configuration of the OCCL error detection platform for optical encoder is designed. Then, the error detection principle of the OCCL optical encoder is analyzed. Finally, the OCCL photoelectric encoder error detection system is established, and the calibration auto-collimator and the regular 23-hedral polyhedron are used to calibrate the accuracy of the detection system. The experimental results show that the new photoelectric encoder error detection platform is frequent, convenient, stable and reliable, and the accuracy of the detection platform can reach 1.64” in the rated working speed range, which can meet the requirements of high precision (2”) and 360° full circle continuous error detection for the encoder.
A New Application of Taguchi Method: Matching and Optimization of Assembly Deviation of Mechanical System
Authors: Mu Xiaokai , Yuan Bo , Wang Yunlong , Sun Qingchao , Zhang Chao , Sun Wei , Liu Chong
Published: September 2021

In order to achieve high assembly accuracy on the basis of low manufacturing accuracy and low cost, a method of deviation factor matching and optimization based on Taguchi theory is proposed. Firstly, the specific process of multi factor matching and optimization is given based on Taguchi theory. Secondly, the orthogonal experiments were set from the aspects of performance index, influencing factors determination, orthogonal table selection and so on, and the best level combination of each deviation was selected to form the factor matching and optimization experiment scheme based on Taguchi method. Finally, taking the horizontal machining center as the object, the Taguchi method is used to match the deviation factors of each mating surface, and the best parameter combination of control factors is A1B2C2D1E1, which verifies the effectiveness and practicability of Taguchi method. The research method in this study provides a strong support for the realization of high assembly accuracy and performance without increasing cost.