bluuebunny/crossref_metadata_2025 huggingface dataset:
Fault Diagnosis Method of Gearbox Based on Sound Pressure Signal Analysis
Authors: Guo Lei , Wang Yongjian , Ju Jinxing , Liu Zhengyong
Published: January 2021

The gearbox structure is complex, so it is difficult to determine the root cause of the problem after abnormal sound appears. The method of sound pressure signal analysis is used to analyze the abnormal sound of gearbox. The spectrum analysis method is used as the data processing method. The sound pressure of a kind of abnormal sound of gearbox is collected. By analyzing its frequency characteristics and structural characteristics, it is judged that the gear is abnormal. The accuracy of the inference based on the result of sound pressure analysis is verified by the shape and position detection of the gear. The results show that through the frequency analysis of the sound pressure signal, the root cause of the gearbox problem can be accurately determined.
A Method of Finding Shortest Paths for Bumblebees
Authors: Yu Guyang , Shi Huajun
Published: January 2021

In October 2010, a new British study said that bumblebees fluttering from flower to flower showed the ability to easily solve the “traveler salesman problem.” There is no good explanation for how the bumblebee solved the problem. In this paper, a simple and efficient algorithm is proposed to explain how bumblebee solves the traveling salesman problem.
Application of Monocular Direct Vision Odometry in Augmented Reality
Authors: Zhang Zuoming , Wang Zixuan , Wang Hanwen , Wang Xin
Published: January 2021

In recent years, the unlabeled augmented reality system has been gradually applied to various mobile devices, among which stable, accurate, and fast registration is the key to realizing this function. For this technique, this paper introduces camera exposure parameters and puts the data association and pose estimation into a unified nonlinear optimization problem. Moreover, the direct monocular vision odometer is transplanted into the augmented reality system through the position adjustment module. We compare it with the traditional visual odometry method that matches the feature points. The results show that this improved method can be used to track more quickly and build a more visual semi-dense point cloud map, which can be used to support the registration and tracking of virtual objects in augmented reality.
Vehicle detection based on point cloud intensity and distance clustering
Authors: Wang Zhao , Wang Xing , Fang Bin , Yu Kun , Ma Jie
Published: January 2021

In the intelligent transportation system, vehicle detection is one of the essential technologies in obstacle avoidance and navigation, however the existing vehicle detection methods cannot meet the actual needs. This paper presents a vehicle detection method combines the intensity and distance information of point cloud, which improves the segmentation performance of nearby objects. Specifically, the data of point cloud collected by lidar is preprocessed first. Then the processed point cloud is clustered by combining its coordinate and intensity information. Finally, the clustered suspected targets are fed to the random forest classifier. Our method can efficiently detect and classify targets in large-scale disordered 3D point cloud with high accuracy. In the real-scanned Livox Mid-40 Lidar dataset, our proposed method improves the detection accuracy by 31% compared with the traditional Euclidean clustering.
Method for constructing multi-dimensional feature map of malicious code
Authors: Ma Haocong , Zhang Ji , Zhou Junhua , Zhai Xiang , Xue Junjie , Ji Hang
Published: January 2021

Malicious code is characterized by a large number of types, rapid increase in number, continuous update of transmission routes, and continuous enhancement of back analysis and back detection methods. Therefore, how to effectively detect and analyze malicious code has been a problem of great concern. This paper studies the features of binary file and disassembly file of malicious code, introduces the concept of information gain, and proposes a method to construct the multi-dimensional characteristic graph of malicious code. Finally, the convolutional neural network is used to classify the multi-dimensional feature graph of malicious code, which provides a new idea for the feature extraction of malicious code.
Breast Regions Segmentation Based on U-net++ from DCE-MRI Image Sequences
Authors: Sui Dong , Huang Zixuan , Song Xinwei , Zhang Yue , Wang Yantao , Zhang Lei
Published: January 2021

Background analysis of breast cancer can depict the progress and states of the tumour, which is based on the whole breast segmentation from MRI images. The focus of this paper is to construct a pipeline for breast region segmentation for the possibility of breast cancer automatic diagnosis by using MRI image serials. Studies of breast region segmentation based on traditional and deep learning methods have undergone several years, but most of them have not achieved a satisfactory consequence for the following background analysis. In this paper, we proposed a novel pipeline for whole breast region segmentation method based on U-net++, that can achieve a better result compared with the traditional U-net model which is the most common used medical image analysis model and achieve a better IoU than CNN models. We have evaluated the U-net++ model with tradition U-net, our experiments demonstrate that the U-net++ with deep supervision achieves a higher IoU over U-net model.
An Integrative Review of Image Captioning Research
Authors: Wang Chaoyang , Zhou Ziwei , Xu Liang
Published: January 2021

In the field of computer vision, image captioning is a new frontier research. The basic task of image captioning is to generate a descriptive natural language for the input image. This paper investigates and analyzes the related research of image captioning. Firstly, the task and application scenarios of image captioning are introduced. Secondly, the image captioning algorithm based on template and the image captioning algorithm based on encoder-decoder structure are analyzed, and the advantages and limitations of each method are discussed. Then, the benchmark dataset and evaluation for image captioning are introduced. Finally, the future development of image captioning is prospected.
Research on “Six in One” Campus Security System Based on Multi-node Data Feedback
Authors: Liu Hongbin
Published: January 2021

In terms of the current incompatibility of various campus monitoring networks and the difficulty of timely sharing as well as the unified storage and management of heterogeneous data in heterogeneous networks, a security monitoring system for multi-node heterogeneous data is designed in the paper, in which the data communication format, sensor encapsulation protocol, gateway design and implementation, database design and monitoring platform construction are studied, realizing the collection and forwarding of heterogeneous network data. Moreover, the data exchange format uses a lightweight format to facilitate the transmission and storage of data, and the sensor protocol is encapsulated to solve the heterogeneous problem caused by the difference in data conversion formulas and meanings between different sensor networks. Furthermore, simulation experiments have proved that the system can efficiently and reliably collect, store and process heterogeneous data in a heterogeneous network in real time, and the built monitoring platform can centrally display and manage campus monitoring information in real time.
Finite control set model predictive control of quasi-z-source inverter photovoltaic grid-connected
Authors: Sha Mai Chao , Zhu Rui Jin , Yang Xu Guang , Han Xu
Published: January 2021

The PI control of the traditional quasi-Z inverter(qZSI) has difficulty in parameter correction and the shortcomings of hysteresis, while the traditional model predictive control (MPC) has a slower response and less precision for current control. In this paper, the current is transformed to the d-q coordinate system, and a suitable output vector is selected according to the limited switch state, which can track the reference current and perform finite set model predictive control (FCS-MPC). Compared with the traditional predictive control method, the current distortion rate is reduced, so that the photovoltaic inverter has a better output result.
Development and Application of Several New Technologies in Safety Locking Device of the Substation Screen Cabinet
Authors: Yue Mengkui , Liu Zhongfeng , Jiang Jinzhou , Qu Hang
Published: January 2021

Anti-misoperation locking device is a locking device for control operation circuit and primary equipment. At present, three faults of relay protection often occurs in the secondary cabinet of substation. There will be a lot of safety threats if the secondary cabinet is lack of locking device. Therefore, in this study effective improvement strategies will be put forward in the aspect of technology and further analyze the technology of the secondary cabinet safety measures locking device and then replace the traditional setting mode of the secondary safety measures so that to technically prevent the violation of regulations in secondary maintenance and effectively prevent the occurrence of three fault events of relay protection. This technology can be applied to the secondary work site of power industry which is significant to ensure the safe operation of power grid. This study illustrates the application effect of the technology of the safety measures locking device for secondary panel cabinet in substation with specific cases which could provide help for the the relevant staff.
The Development and Application of Support Vector Machine
Authors: Jun Zhao
Published: January 2021

Support Vector Machine(SVM) algorithm has the advantages of complete theory, global optimization, strong adaptability, and good generalization ability because of it on the basis of Statistical Learning Theory’s(SLT). It is a new hot spot in machine learning research. This article first systematically studies some basic concepts of SVM and the optimization of SVM. In addition, this article also discusses the application of SVM in modern machining, protein prediction and face detection. Through these applications, the performance characteristics and advantages of SVM can be reflected. At the end of the article, some shortcomings of SVM are introduced, and the development trend of subsequent SVM is pointed out accordingly.
Operation Mode of DC Traction Power Supply System and its Feeder Protection
Authors: Ma Min
Published: January 2021

At this stage, DC traction power supply systems are widely used in the development of China’s rail transit. In order to ensure the safety of rail transit, we need to strengthen the research work of DC traction power supply system. We can study and explore from the operation mode of the power supply system and feeder protection measures. Among them, we must pay special attention to feeder protection measures, as far as possible to ensure the safe operation of the DC traction power supply system, so as to ensure the stable operation of rail transit.
A Method of Plasma Quenching in the Gun Barrel
Authors: Luo Tian-Fang
Published: January 2021

In order to extend the service life of the barrel and improve its corrosion resistance and wear resistance, plasma quenching technology successfully processed the inner hole material. The treatment effect is obtained by making the analysis of the microstructure, hardness and tribological properties. The results show that the plasma quenching of the barrel material can form a martensitic hardening layer on the surface, when the surface hardness is increased by 725 HV, and the surface abrasion resistance is enhanced by 10 times. This technology provides a new way to extend the life of the barrel.
This paper analyzes the operation mechanism of integrated circuit electrostatic discharge (ESD) protection device
Authors: Xu Qing
Published: January 2021

Electrostatic discharge, as a common natural phenomenon in daily life, seriously threatens the reliability of integrated circuit products. In order to ensure the yield of the chip, the protection circuit on the chip has become an essential and important module in the circuit design. With the continuous development of integrated circuit technology, chips are developing towards the direction of smaller area, faster speed and higher level of integration, while traditional devices such as simple diodes, tubes and SCR on integrated circuit can no longer complete the protection task of chips under advanced technology. Through the research and discussion of this paper, the methods and strategies of electrostatic discharge protection design of integrated circuits and how to choose the best electrostatic discharge protection scheme for different integrated circuits are basically mastered.
Design of Multi-frequency Analog Transmitter of Magnetic Source Based on Selective Harmonic Elimination Technology
Authors: Yutong Zhang , Yi Liu , Shiqing Cai , Shilong Wang
Published: January 2021

Electromagnetic waves of different frequencies penetrate formations at different depths, so the frequency component of the transmitted waveform determines the detection range of electromagnetic exploration. The selective harmonic elimination pulse width modulation technology was originally used for harmonic elimination. In this paper, SHEPWM is used for harmonic enhancement and the control of harmonics. In addition, the current SHEPWM technology mostly uses various heuristic algorithms, which are not ideal for solving higher-order nonlinear equations. This paper uses the third-order convergence arithmetic mean Newton iteration method to solve the nonlinear equations. The number of solving nonlinear equations can reach 41, and the controllable energy ratio can reach 40% to 50%. Finally, the amplitude and phase of each frequency component of the current waveform can be controlled, which provides a reference for the SHEPWM technology to enhance harmonics.
Recoil reduction method of gun with lateral nozzle controlled by electromagnetic valve
Authors: Si Peng , Qiu Ming , Liao Zhenqiang , Song Jie , Ma Longxu
Published: January 2021

A new recoil reduction method of gun was proposed in this work to reduce the recoil without reducing the muzzle velocity and changing the continuous firing mode. Its recoil reduction mechanism was studied based on the two-phase flow theory. First, combining the gas-solid two-phase flow in the barrel, the electromagnetic control in the electromagnetic valve, the fluid-solid coupling in the piston cavity, and the transient gas flow in the exhaust pipe, an eight-stage mathematical model of the gun propulsion process was established. Next, the propagation law of the rarefaction wave in the barrel was discussed. Then, the propulsion difference between the gun proposed here and the traditional gun was presented. The results showed that the proposed method could reduce the recoil impulse by 38.20% without reducing the muzzle velocity under reasonable matching of the structural parameters.
Research on the Temperature Distribution of the Hollow Conductors in the Self-circulating Evaporative Inner Cooling System for High Power Rectifier Equipment
Authors: Yan Jing , Yu Shunzhou , Cao Rui
Published: January 2021

In the evaporative inner cooling system for high power rectifier equipment, the thyristor and quick fuse are both cooled double-sided via hollow conductors. Different from the previous study on the system with single structure, the self-circulating system for high power rectifier equipment has composite structure. Then the system with composite structure may show different heat transfer characteristics. So in this paper, the temperature distribution of the horizontal and vertical hollow conductors in the self-circulating system was studied through theoretical analysis and simulation.
Flowing model of weld pool during vacuum electron beam welding
Authors: Wu H.Y. , Jiang F. , Wang S.L. , Chen Y.H.
Published: January 2021

The flowing behaviors of weld pool during electron beam welding (EBW) were investigated using T2 copper by physical experiments. A flowing model of weld pool is developed basing on the morphologies observation and analysis. The flow of weld pool for fully penetrated weld is composed of upward convection flow around the keyhole, horizontal flow toward fusion line near top surface and bottom surface, and horizontal flow backward alone weld direction. According to the flowing model, the formation of cavity defection and characteristic of weld in cross-section can be understood.
Research on Three-phase Unbalanced Overvoltage Suppression Method Based on Active Inverter
Authors: Li Yibo , Cao Wensi
Published: January 2021

A three-phase unbalanced overvoltage suppression method based on active inverter is proposed for the three-phase unbalanced voltage caused by the imbalance of three relative parameters in the power grid. According to the zero-sequence current generated by the neutral point in the three-phase unbalanced state in the system, the tracking inverter circuit is correspondingly injected with a certain magnitude and phase current to compensate the three-phase unbalanced current without changing the grid-to-ground insulation. Under the condition of parameters, the three-phase unbalanced overvoltage is quickly and accurately suppressed, and the three-phase voltage balance of the grid is forced. Due to the complex and variable structure of the distribution network, the three-phase unbalance phenomenon is particularly prominent. Therefore, the distribution network is very representative. The reliability of the proposed method is verified by simulation analysis.
Pine-like concentrating power generation device
Authors: Shi Ting , Wang Xincheng , Xiong Xinhong
Published: January 2021

Today, when energy problems are increasingly prominent, the development and utilization of solar energy has become the focus of achieving sustainable energy development. However, due to the dispersion of solar radiation energy and atmospheric absorption, the radiation intensity directly reaching the surface of the earth is relatively weak. The existing linear Fresnel concentrators in engineering are huge in size and have low concentration ratios. In order to increase the concentration ratio of the CSP device, the pine-like CSP device combines the advantages of both the CSP device and the tree-like structure. It has the advantages of low cost, high efficiency, and small footprint, which will solve the problem. This will be a useful attempt to solve the problem of urban solar energy utilization and give new ideas to solve the problem.
Analysis on the Influence of Wind Power Participating in Frequency Modulation on Low-frequency Oscillation in Yunnan Power Grid
Authors: Yang Lei , Gao Jingye , Ma Zun , Huang Wei , Zhang Dan , Xing Chao , Xiang Chuan , He Xin
Published: January 2021

Low-frequency oscillation in Yunnan power grid with a high proportion of hydropower units is prominent. With the continuous access of large-scale new energy sources, it poses a serious threat to the frequency stability of the power grid. Based on the simulation model of Yunnan power grid in 2020, this paper studies the effect of wind power participating in frequency modulation on the damping of Yunnan power grid. Several low-frequency oscillation modes in Yunnan power grid are given through the analysis of two typical operation modes of Xia Da and Chun Xiao. This paper also analyzes the effect of the fan on the low-frequency oscillation mode of Yunnan power grid after adding primary frequency modulation and inertial control. The results show that both inertia control of fan and excessive primary FM sag coefficients will reduce the damping of the system. After wind power is involved in frequency modulation, a favorable effect on the damping of the low-frequency oscillation mode of Yunnan power grid can be produced by setting the control parameters appropriately.
Design and experimental study of minitype modularized fluorescence microscopic imaging system and focusing mechanism
Authors: Zhang Yang , Fu Weiwei , Liu Min , Zhu Hailong
Published: January 2021

In the global in vitro diagnostic(IVD) market, point-of-care testing(POCT) features the largest market share, while POCT in China features small market share. With the development of consumption upgrading, urbanization and medical reform of China, this kind of real-time detection without central laboratory features huge market demand and potential. POCT is a testing method, which can obtain test results in just few minutes with portable equipment and supporting reagents. In this paper, a minitype modularized fluorescence microscopic imaging system is proposed, which is used for blood cells detection, microbial observation and pathological section scanning. In order to meet the needs of portable, miniaturized and chip-type, a linear objective lens switching and focusing mechanism (LOLSFM) has been designed and developed, which changed the rotating disk switching mode of existing microscope. Finally, the precision and verticality of the LOLSFM are verified by experiments. The imaging quality of minitype modularized fluorescence microscopic imaging system.
Intelligent Anti-virus Mask Based on Gas Detection Sensor
Authors: Gong Yide , Wang Yiting , Chen Jin
Published: January 2021

This article developed an intelligent anti-virus mask, which is composed of MQ-135 sensor, single-chip microcomputer, valve mechanism and so on. When there is no poisonous gas, the valve of the canister of the mask is opened to breathe normally; when there is poisonous gas, the valve of the canister of the mask is closed and an alarm is issued, and air enters and exits through the canister. Experiments show that the gas mask can accurately detect the concentration of alcohol gas volatilized by alcohol diluents of 30%, 50% and 80% concentration, and trigger the mask to perform alarm and protective actions in a timely and accurate manner. The experiment verifies the safety and versatility of the smart gas mask, indicating that the product has high engineering application value and practical promotion significance.
Numerical Analysis and Experimental Study on High Frequency Piezoelectric Feeding Device of Block Materials
Authors: Li H S , Li S Y
Published: January 2021

According to the needs of ultrasonic vibration feeding, we developed an ultrasonic piezoelectric feeding device. The device with unrestricted length and width and the feeding speed is uniform. we analyzed feeding the boundary conditions and calculated the expression of the average feeding speed. Using ANSYS to analyze the relevant parameters of feeding vibrator, we made the piezoelectric feeding vibrator and carried out a series of experiments to test the feeding effect by using Laser Doppler vibrometry. The results showed that the amplitude of the first order longitudinal vibration is maximum when the excitation frequency is 34.7kHz; When the feeding device is at the excitation frequency and the driving voltage is 130V, the feeding effect of the heavy material with smooth surface is very good (M10×30 bolts, M20 nuts); Materials with rough surface and lighter than 0.5g have almost no feeding capacity (tablets and grains), and the feeding device has certain selectivity for materials; When the mass of material is 72g, the feeding speed can reach 60.45mm/s. The study provides a reference for the research of ultrasonic feeding device.
Automatic analysis model of power grid infrastructure project cost level
Authors: Lin Yubin , Hu Zhenda , Zhang Chengwei , Fu Benzhao , Zhang Shiming , Hua Xiaolu
Published: January 2021

Under the development of large-scale power grid investment, precise investment management has important guiding significance for improving power grid investment control and efficiency. In this paper, combined with the current situation of power grid infrastructure project cost management and pricing, using the ABC prediction method, through the analysis of cost price mode and characteristics, the cost theory and method innovation and application are carried out. This method is innovative and verified by experiments.
Vibration test and structural optimization analysis of axle box bracket
Authors: Wang Hongquan , Yang Jing , Niu Chengliang
Published: January 2021

The bracket cracked and ground cable broken have occur to axle box many times on certain line metro vehicle. In view of this kind of accident, vibration test, vibration analysis, modal analysis as well as structure optimization are carried out for the axle box bracket of the subway. The test results show that the first transverse bending mode of the bracket is excited by the line vibration, so, it breaks due to vibration fatigue in the resonant state. The simulation results show that the modal frequency can be increased by thickening the bracket and optimizing its structure, so that avoiding resonance phenomenon and increasing its fatigue life. Finally, experiments are carried out to further verify the conclusion, and the structure that performs best can be chosen among multiple optimizations.
Finite Element Analysis of Thermal Load Characteristics of Dry Dual Clutch
Authors: Xie Chao , Wu Guiyu , He Shijie , Zhang Yong , Tian Jie
Published: January 2021

The dry dual clutch of a passenger car is taken as the research object, and its three-dimensional model is established by software CATIA. On this basis, the thermal load characteristics of the dry dual clutch under the condition of multiple starting on the ramp are analyzed by software ABAQUS. The analysis results show that the temperature rise and thermal stress of the parts caused by the friction heat are within the normal range, which indicates that the designs of the pressure plate and the intermediate driving plate meet the requirements. This study obtains the distributions of the transient temperature field of the clutch friction pair under the conditions of the multiple starting, which has an important reference value for the design and optimization of the dry dual clutch.
Online Over voltage Monitoring Method Based on Contactless Induction Technique
Authors: Lu Yufeng , Wang Jialin , Su Yi
Published: January 2021

The operation experience and research shows that over voltage is the main factor which caused grid insulation damage in the power system, but also the main reference option of electrical equipment in insulation conditions selection. Research on system broadband transient current sensing technology based on advanced magnetic field sensors for non-contact measurement, research on system broadband over voltage sensing technology based on advanced optical electric field sensors for non-contact measurement, and development of new micro-sensing technology Distributed connection of non-contact sensing terminals, building a sensor network system for transparent sensing of transient information in substations, realizing passive and wireless communication design, realizing transparent sensing of incoming and outgoing transient information in the station, portable and easy to install, which is the transient information of the power grid Obtain analysis to provide solid data support, greatly improve the level of transient information monitoring in the substation, and improve the reliability of power grid operation.
Research and Application of Transient Transparent Sensing Technology in Substations Using Internet of Things to Distributely Connect Non-contact New Broadband Sensor
Authors: Lu Yufeng , Wang Jialin , Su Yi
Published: January 2021

When the equipment in the substation undergoes major disturbances (such as short-circuit failure, system oscillation, frequency collapse, voltage collapse, line lightning intrusion, etc.), electrical quantities (voltage, current, frequency, etc.) will undergo transient changes. This process is to correctly analyze the accident. The basis of cause can be used to evaluate the operating status of equipment, find fault points, and quickly deal with faults. However, the current domestic transient information perception in substations still needs to be developed: 1) The existing system data sources are PT and CT data, which are restricted by the bandwidth of PT and CT, and the high-frequency monitoring accuracy is not high; 2) the construction and maintenance of centralized screens are complicated. Using a large number of secondary cables; 3) the redundancy is small, and it is not easy to increase and upgrade. Therefore, it is urgent to develop a new type of distributed substation transient information sensing technology, to develop a system wide-frequency transient current sensing technology based on advanced magnetic field sensors to achieve non-contact measurement, and to develop a system broadband transient based on advanced optical electric field sensors to achieve non-contact measurement.
Troubleshooting of a 330MW turbo generator unit during commissioning
Authors: Ma Lyuzhou
Published: January 2021

During the commissioning stage of a 330MW turbo generator unit, several serious defects occurred, such as low vacuum of condenser, abnormal vibration of shafting and bearing damage. Through fault analysis and vibration test, the hidden danger in design, manufacture and installation were found out and solved, the unit successfully completed 168 hours full load test run and put into operation.
Study on Control Strategy for Composite Power Supply System of EV
Authors: Tian Liyuan , Liu Xiaofei
Published: January 2021

At present, countries all over the world are vigorously developing new energy vehicles. Many countries and regions have introduced policies to stop the production and sales of traditional energy vehicles. However, the large-scale industrialization of pure electric vehicles has encountered the constraints of power batteries, and its main problems are reflected in the specific power of the power battery is low. This paper analyzes the current situation of electric vehicle composite power supply, points out the problems and solutions of electric vehicle energy storage system, in order to obtain the expected development and test results.
Failure analysis of 15CrMo catalytic settler
Authors: Jiang Chengjun , Zou Xiaohui , Wang Wei , Li Qian
Published: January 2021

The thinning failure of 15CrMo catalytic settler occurred in a heavy oil catalytic unit of a factory after service for 8 years. The thinning failure reason of the catalytic settler shell was analyzed by macroscopic inspection, metallographic examination, microscopic inspection, chemical composition analysis of the coke layers and oxides of iron test in the outer shell coke layer. The results showed that the working temperature exceeds the anti-oxidation temperature of 15CrMo in an oxidation environment, causing severe high-temperature oxidation thinning on the outer shell of the settler.
Theoretical research and application development of self-sensing micro-flow injection device
Authors: Huang Jie , Shi Liping
Published: January 2021

In this study, the main content is based on theory and application of piezoelectric ceramic digital micro-injection, analyzing the first inverse piezoelectric effect and secondary positive piezoelectric effect of piezoelectric ceramics through theory and experiments, and using its principle to design self-sensing digital micro-injection structure. This paper designs a kind of digital micro-injection device which is based on the first inverse and secondary positive piezoelectric effect by according to the theoretical research and experimental verification of piezoelectric ceramic’s piezoelectric effect. Push the syringe plunger under the action of the piezoelectric ceramic’s first reverse piezoelectric effect to achieve a fluid flowing. At the same time, secondary piezoelectric effect can sense the injection volume to achieve self-sensing microinjection. Designing the overall structure of the program and validate the feasibility of the program is reasonable and practicable through feasibility experiments.
Construction of Evaluation Index System for the Adaptability of Narrowband Internet of Things and Power Business
Authors: Wang Yao , Yun Liang , Sun Xiaoyan
Published: January 2021

With the continuous extension of Smart Grid from the grid side to the user side, the expansion of emerging business is deepening day by day. In terms of terminal access quantity demand of provincial companies, from the original substation of 100 kilo level to the 10 kV distribution system of 100 000 class and the user terminal of 1 million or even 100 million level. Therefore, massive terminal communication is an urgent problem to be solved in power communication network. At present, the State Grid Corporation of China is planning to build terminal communication access network, mainly using optical fiber and Narrow Band Internet of Things wireless technology, mainly to solve the 10kV distribution system; and the communication access of tens of millions or even hundreds of millions of user terminals urgently needs a suitable communication technology to solve. At present, NB-IOT technology has the characteristics of enhanced coverage, ultra-low power consumption, mass access, etc., which can meet the above requirements. This paper mainly describes the construction of NB-IOT technology adaptability evaluation index system, introduces the evaluation method of power narrowband Internet of things, and the evaluation results and analysis of adaptability.
Nonlinear control of active power filter based on LQR control
Authors: Liu Yang , Yang Jian Feng , Qi Ren De , Meng Ning Ning
Published: January 2021

In order to improve the ability of real-time tracking and compensating harmonic of three-phase active power filter (APF), a nonlinear sliding mode control strategy of APF is proposed based on the state feedback linearization theory. In order to improve the dynamic performance and tracking ability of APF system, the affine nonlinear model of APF system is established, and the nonlinear control strategy of current inner loop is designed. The control parameters are adjusted by LQR method. In order to adjust and stabilize the DC voltage of the system, the slip mode control (SMC) is used to design the voltage outer loop. The simulation and experimental platform are built. The experimental results show that the method has good dynamic response, steady-state characteristics and robustness.
Utilizing GPGPUs for simulating quantum circuit
Authors: Xu Yuanfei , Zhang Lixing
Published: January 2021

State vector describing the state of an n-qubit quantum system requires 2ncomplex numbers, which means the memory usage of simulating a quantum computer grows exponentially with respect to the number of qubits. For the memory of a single hardware is limited, distributed computation is necessary for simulating quantum systems with large number of qubits. In our proposal, we developed a multi-GPU solution. State vector is divided into several chunks and allocated to different GPU device. Making it possible to simulate quantum circuits of any size on appropriate GPU cluster. We analyse the theoretical computation resource and come to the conclusion that memory copy bandwidth between GPUs is the bottleneck of time consumption. Total execution time is O(logDN/DN) if peer-to-peer memory copy is supported, otherwise time elapsed is O(logDN) where DN is number of GPU devices. Memory consumption on one GPU is O(1/DN).
Research on economical sawing equipment for auto roll-forming frame part adapted to fast switching of multiple varieties
Authors: Peng Li-Ming , Qian Hua-Min
Published: January 2021

Precise angle sawing is an important process to ensure the auto roll-forming frame parts be assembled and welded accurately. Large enterprises can adopt special sawing machine and fixture to meet the requirements. However, this method is not suitable for small enterprises due to its large investment and insufficient flexibility of the manufacturing system. Considering the multi-varieties and small batches production characteristics, economical sawing equipment based on the general cutting machine platform equipped with quick change fixture is introduced. By changing the fixture position on the platform, and replacing a few necessary elements, this equipment can accomplish different angle precise sawing for various auto roll-forming frame parts. Finally the economical technology renovation purpose is realized.
Mechanized operation mode of the key link of Chinese stem and leaf vegetable production
Authors: Guo Qian
Published: January 2021

In China, the comprehensive mechanization level of stem and leaf vegetable production is only about 20%, and the labor cost accounts for about 65% of the total production cost, with high labor intensity and high cost. The mechanization production level of stem and leaf vegetables in China is low, and there are some problems, such as single function of machinery and tools, poor adaptability, low production efficiency, poor operation quality, various links of machinery and tools are not matching, and the planting and agronomy of leaf vegetables are not matching. In this paper, the key technologies and future development trend of the mechanization of stem and leaf vegetable production are put forward, and the direction of the research and development of stem and leaf vegetable production technology and equipment is pointed out.
A Task-Driven Applicable Theory of Autonomous Load Control
Authors: Liu Xinan , Ma Xiao , Yang Shuo , Zhou Na , Yang Xiaoyu , Liu Rui
Published: January 2021

Following manual manipulation to manual remote control, special vehicles are now developing towards task-oriented autonomous load control. Based on the original remote load control system, an autonomous control system architecture composed of “decision-making layer-planning layer-control layer-executive layer” was proposed in this paper, and the “task chain-action chain-instruction chain” autonomous task load control method was devised. This theory transforms the remote fire control system that receives operating instruction and controls units, into a task-driven load system that receives tasks to realize automatic/autonomous control. This provides theoretical support for the autonomous combat of unmanned equipment in the future.
Design of indoor unmanned airship propelled by ionic wind
Authors: He Zhongzheng , Li Pengfei , Wang Wei , Shao Liwei , Chen Xi
Published: January 2021

The indoor unmanned airship is a lighter-than-air aircraft that can hover in the air for a long time without consuming energy. Indoor unmanned airships are widely used in indoor inspections, special operations, commercial advertising, education and scientific research. In this paper, an indoor unmanned airship propelled by ionic wind is designed. The airship can complete motions such as forward and yaw, and almost no noise and vibration are generated during the working process.
Assist the elderly bathing machine
Authors: Chang WenQi , Liu HaoYan , Lu JingJia , Chen Yun
Published: January 2021

Data show that the degree of aging in my country is increasing year by year. Moreover, the elderly’s bathing problem still plagues families. Based on the above situation, the project team designed an auxiliary bathing machine for the elderly. The bathing machine can wash the head, back, limbs and other parts of the elderly that are not convenient for washing, and at the same time assist the elderly to lie down and get up, and monitor the vital signs of the elderly during the bath. The control mode of the bath machine is independent control of each module, and the elderly can activate each functional module by voice or manually. The coordination and cooperation between the various modules effectively deal with the problem of bathing for the elderly living alone, which has high practical value and promotion value.
Mechanical smart cleaning table
Authors: Duan Jinhong , Gan He , Yu Quanzhang , Chen Yun
Published: January 2021

Smart home is the inevitable development trend of future home furnishings. As an integral part of the home system, the dining table is bound to face a qualitative leap. As people yearn for a better, more comfortable and convenient life, the development of the dining table will become more intelligent and humanized. At present, people have a great demand for a variable dining area, and hope to avoid the tedious cleaning of the table after eating, and desire to be free from housework. Based on the above background, the team members designed a new type of self-cleaning dining table-mechanical intelligent cleaning dining table. The dining table has the characteristics of ingenious structure, diverse functions and stable performance, including three functional modules: folding and extending, table cleaning, and garbage collection. The ingenious cooperation between the various institutions can realize the folding and extension of the dining table, table cleaning and garbage collection functions. The mechanical intelligent cleaning table saves people’s time, facilitates people’s lives, and has high practical value and promotion value.
Cigarette end detection based on EfficientDet
Authors: Liao Jianhao , Zou Jiayu , Shen Ao , Liu Jinfu , Du Xiaofei
Published: January 2021

In the process of building a harmonious society in China, smoking in public places is difficult to curb. However, with the continuous development of computer vision, object detection algorithm plays a key role in the above video detection scene. However, if the detection process is not real-time, it can not be applied to smoking scenes in public places, giving people timely judgment. After analyzing a variety of target detection algorithms, this paper considers that EfficientDet can achieve high efficiency under a wide range of resource constraints, and can easily carry out multi-scale feature fusion, so that it has high speed and accuracy in the process of target detection. In this paper, Efficientnet is used as the backbone feature extraction network, and a set of fixed scaling coEfficients are used to scale the depth, width and resolution of the network for preliminary feature extraction, so as to obtain three effective feature layers. Then, in order to improve the prediction level and enhance the feature extraction, the three effective feature layers are transferred to bifpn with cross-scale connection optimization The prediction results can be used as the evaluation results of the model. The evaluation results show that EfficientDet has high mAP.
Design of Laser Cleaning System for Large-scale Plane Workpiece
Authors: Ma Qingzeng , Ren Yuan , Jin Shuo , Nan Leiguang , Ge Hailong , Cheng Wei
Published: January 2021

Surface cleaning is an essential procedure to improve quality and performance of workpiece in modern industrial manufacturing. Among surface cleaning technologies, laser cleaning has been regarded as the most promising green cleaning technology. Laser cleaning is a green cleaning technology that will not cause any environmental pollution. Laser cleaning has the ability of cleaning the area of the designated shape. A set of laser cleaning system that consists of two-dimensional galvanometer and 3-axis motion platform, was designed in this paper. The two-dimensional galvanometer was used to clean the area of the specified shape. The 3-axis motion platform expands the limited cleaning area of the two-dimensional galvanometer to a larger area. Laser displacement sensor is utilized to ameliorate the cleaning quality. To improve the cleaning accuracy of the system proposed in this article, a camera was adopted to recognize the origin of the workpiece and correct the pose of the workpiece. Experimental results demonstrate the performance of the proposed system for large-scale plane workpiece.
Influence of Circumferential Uneven Inlet Conditions on the Aerodynamic Performance of Turbine Stator
Authors: Ji Bing , Wang Zhiduo , Li Jun
Published: January 2021

The application of the combination of rotating detonation combustor and turbine to propulsion system is a recent research focus. This paper verifies the feasibility of this combined propulsion method through numerical simulation, and the flow law and flow loss mechanism in the turbine stator passage under complex inlet conditions are obtained. The results show that the flow field in the turbine stator has serious circumferential unevenness. The interaction between the rotating pulsating wave and the blade is the main cause of flow loss.
Design of a new type of deep hole boring device
Authors: Cai Hao , Dong Zhen , Zhang Zhi Bing , Cui Shuai
Published: January 2021

When boring deep holes, as the workpiece hole becomes deeper and deeper, the size of the boring bar is large, the overhang is large, the vibration of the boring bar is large, and it is easy to deform, which makes the ordinary deep hole boring tool unable to meet the actual complex working conditions. In order to reduce the vibration and deformation of the boring bar and further improve the machining accuracy of the workpiece, a deep hole boring device with auxiliary support is designed. The adjustable support provided by the device can play a role of fixing and guiding during processing, thereby effectively reducing processing vibration and deformation and improving processing accuracy. And completed the trial production and processing experiment of the device prototype. The results show that the machining accuracy of the new cylindrical deep hole boring device is very high and meets the design requirements.
Review of the Research on Augmented Reality Maintenance Assistant System of Mechanical System
Authors: Jia Wenze , Zhu Junyao , Xie Lizhong , Yu Cungui
Published: January 2021

In order to ensure the normal operation of mechanical system and solve the problems of complex structure and insufficient cognition caused by mechanical system updating, the advantages of applying augmented reality technology in the field of fault diagnosis and maintenance are analyzed. Firstly, this paper summarizes the application of augmented reality technology for maintenance assistance cases at home and abroad, analyzes its industry characteristics and application advantages, then summarizes the key technologies of augmented reality, and finally prospects the development trend of the system application.
Structure Design and Simulation of Portable Intelligent Gauge Calibrator Based On ANSYS
Authors: Liu Liang , Zou Wen Zhe , Liu Chuang , Shao Junyi , Liu Yunjia
Published: January 2021

Gauge industry is an indispensable part of China’s railway inspection industry. There are some problems in the traditional gauge industry, such as large volume and low intelligence. In view of the above key points, this paper designs a new portable intelligent gauge calibrator, which greatly reduces the volume of the device. Through the upper computer operating the internal control unit of the device, the automatic measurement of the instrument is carried out. The structure of the new gauge calibrator is analyzed and demonstrated by ANSYS simulation software.
Analysis of docking tolerance capability of underwater tool-switching device
Authors: Gong Haixia , Tang Wei , Tan Bowen , Wang Liquan
Published: January 2021

As part of the Underwater Mechanical hand and Tool Box System, the underwater tool-switching device can carry variety kinds of tools that have general interfaces during one-time underwater operation, like polisher, driller, cutting saw, torque wrench. By operating the underwater ROV Mechanical hand using the remote control system on the land, the workers are able to switch all kinds of tools quickly so that they can enhance the work ability and improve the efficiency of the Underwater Mechanical hand. In this paper, the geometric conditions required for the docking of the mobile end and the fixed end of the docking device are analyzed. Through the projection method, the three-dimensional docking process is transformed into the two-dimensional position equation on the main docking plane, and the mathematical model is established to obtain the docking tolerance range. Then, the simulation experiment is carried out by Adams to verify the correctness of the tolerance theoretical calculation.