bluuebunny/crossref_metadata_2025 huggingface dataset:
Detection of active segments of lower limbs EMG signal based on time-domain variance combined with short-term energy
Authors: Zhang Chao , Wu Qian , Ma Zhongjing
Published: December 2022

Using EMG signal to realize gesture recognition is a technical difficulty in the application of EMG signal. In order to solve this problem and ensure the accuracy and timeliness of action classification and recognition, it is proposed to use time-domain variance combined with short-term energy to set a double threshold algorithm to detect effective activity segments. Based on the short-term energy and the zero-crossing rate, the minimum energy threshold and the frame window data variance value are designed. Then the original signal is processed by frame length and frameshift, and the complete signal data is divided into several small Windows. Finally, the effective activity segment is intercepted after comparing the upper and lower limits of the time-domain feature extraction variance with the set threshold. The experimental results show that the algorithm is effective in realizing the detection and interception of the start and end points of actions when processing single-channel or multi-channel EMG signals.
Optimization of Torque Performance of Permanent Magnet Synchronous Motor Based on the Taguchi Method
Authors: Pan Yue , Yu Yinquan
Published: December 2022

In order to improve the driving capability of the permanent magnet synchronous motor (PMSM), this paper optimizes the stator slot and rotor optimization variables of PMSM with the average torque and torque ripple as the optimization objectives. Firstly, the sensitivity analysis is used to find out the optimization variables which have a greater influence on the optimization objective from the initial selection of optimization variables. Secondly, the Taguchi method and Finite element method (FEM) are used to derive the best combination of optimization variables. Finally, the initial and optimized FEM model is built. The results showed that the average torque of the motor was improved by 27.27% and the torque ripple is reduced by 46.99% after the optimization is done.
Energy management strategies for hybrid ships and Unmanned Underwater Vehicles
Authors: Zhang Mengyao , Gu Haitao , Guo Jianhua
Published: December 2022

Both ships and unmanned underwater vehicles (UUVs) have played a great role in the human exploration of the ocean and the investigation of marine resources. Their endurance of them is limited by the onboard energy storage, and the benefits of hybrid ships and UUVs in terms of energy conservation and emission reduction technologies are increasingly clear. The secret to attaining energy conservation while maintaining power performance is energy management. The management of energy for hybrid ships and UUVs are summarized in this work. First, this article includes the state of the art in energy management techniques for autonomous maritime vehicles and hybrid ships. and summarizes the hybrid energy management objectives for different purposes. Second, it analyses the latest progress of hybrid energy management strategies at the present stage and compares the benefits and drawbacks of existing energy management strategies in a comprehensive and in-depth manner. Finally, the paper summarizes their shortcomings and provides an outlook on the future development of hybrid energy management strategies.
CNN-SVM Spectrum Sensing in Cognitive Radio Based on Signal Covariance Matrix
Authors: Wang Qi , Guo Bin
Published: December 2022

Among the basic components of cognitive radio technology is spectrum sensing technology. Cooperative spectrum sensing is also a crucial factor research directions of spectrum sensing. Due to the problems of channel fading and hidden nodes, the spectrum sensing based on a single node cannot meet the requirements of the cognitive radio system for the primary user (PU) detection performance. A spectrum sensing algorithm is based on CNN-SVM and covariance matrix. In this algorithm, the covariance matrix of the signal is input into the convolutional neural network for feature extraction. Secondly, the result of the fully connected layer is taken as the input of the support vector machine for training to obtain a classifier, and finally, spectrum sensing is performed. The simulation outcomes demonstrate that the algorithm suggested in this research works outperform other algorithms in this paper. When the signal-to-noise ratio is -14 dB, the false alarm probability is 0.1, the number of secondary users is 32, and the detection probability reaches 0.81.
A Novel Finite-Time Fault Observer for the Actuators of the Industrial Manipulator
Authors: Liu Fuqiang , Ma Zuxing , Zhao Bin , Zhong Songyi
Published: December 2022

A novel fault observer which can accomplish fast finite-time convergence is proposed for the second-order manipulator system with disturbance and actuator faults in this paper. When the degree of actuator fault exceeds the upper bound on the external disturbance, both the fault and disturbance are considered as lumped actuator faults for estimation. A fast finite-time extended fault observer is constructed and demonstrated for estimating the total fault with uniformly and ultimately boundedness. The effiectiveness and superiority of the developed fault observer are illustrated by comparative experiment results on a two-joint manipulator model.
Laser Additive Remanufacturing Cladding Thickness Detection System
Authors: Lu Tong , Cheng Wei , Dong Shiyun , Ge Hailong , Li Wenlong , He Jianqun , Hu Zhiwei
Published: December 2022

As an important parameter in laser additive remanufacturing technology, cladding thickness is related to the quality of remanufacturing. Thickness detection during the cladding process can help improve the cladding quality and facilitate manual adjustment of parameters in real time to optimize the cladding thickness. This system develops a set of cladding thickness detection system based on laser displacement sensor. The system consists of hardware and software parts. The hardware part includes laser displacement sensor, mounting plate, digital signal acquisition device and laser cladding system. The software part a set of data acquisition software is developed according to Visual Studio. The system uses two methods to measure, and eliminates the error caused by the tilt factor of the worktable, and realizes the online measurement of cladding thickness.
Research on SVPWM control algorithm based on dual three-phase permanent magnet synchronous motor
Authors: Ma Lihong , Qiu Xiaochu
Published: December 2022

Compared with the three-phase permanent magnet synchronous motor, the dual-three-phase permanent magnet synchronous motor has the characteristics of high reliability, small torque fluctuation, and strong fault tolerance, which is suitable for application in the fields of ships, aerospace, and electric vehicles. However, due to the presence of harmonic sub-spaces in dual-three-phase permanent magnet synchronous motors, small voltage distortions can lead to excessive harmonic currents. In this paper, the dual-three-phase permanent magnet synchronous motor is used as a research object, and a control algorithm is designed to suppress its harmonic current. The traditional 48-sector SVPWM does not take into account the simultaneous action of the three-phase bridge arm of the same group of inverters during sector conversion, so it generates a large harmonic current when sector conversion. Therefore, this paper proposes an improved 48-sector SVPWM, which makes a partial adjustment to the vector selection of each sector based on the traditional 48-sector SVPWM, so that the zero vector selection of each sector is the same, avoiding the situation that the same group of three-phase bridge arms acts simultaneously when the sector is converted. The basic principles of improving the 48-sector SVPWM are introduced in detail, and the simulation analysis is carried out in MATLAB, which verifies the correctness of the theoretical analysis in this paper. The results show that this algorithm not only inherits the advantages of the traditional 48-sector SVPWM that is easy to implement in hardware, but also further reduces the harmonic current of the stator.
Improved Object Detection Algorithm Based on Faster RCNN
Authors: Wang Hua , Jiang Shifa , Gao Yang
Published: December 2022

This paper studies the target detection algorithm based on Faster R-CNN. Aiming at the insufficient regression accuracy of the target prediction box, an improved target detection algorithm based on Faster R-CNN is proposed. Firstly, ResNet 50 residual network is selected and the feature pyramid (FPN)is introduced to improve the ability of target detection. Secondly, GIOU is introduced to optimize the anchor frame to improve the positioning problem of the target candidate frame. Finally, a bilinear interpolated ROI Alian is used to replace the original ROI pooling, which avoids the pixel error caused by two quantization operations. The data set Pascal VOC 2012 is used for training and testing, and it is verified that the proposed algorithm improves the mAP by 5.4% compared with the original algorithm.
An Improved EKF Algorithm for SOC Estimation of Lithium Battery Considering Temperature Effects
Authors: Zhao Moxuan
Published: December 2022

In order to improve the estimation accuracy of the state of charge (SOC) of lithium-ion power batteries during use, an estimation method that considers different temperature effects is proposed in this paper. First, the second-order resistor-capacitor (RC) circuit model is selected as the research model based on a comparative analysis of different models. Then, the parameters in the circuit model are identified online in real time under different temperatures to analyze the temperature effects on internal parameters. Lastly, the noise variance can be automatically adjusted according to the environment by using the improved extended Kalman filter (EKF) algorithm with the differential evolution algorithm, which optimizes the fixed process noise variance in the original EKF algorithm. The changing noise variance is substituted in the original EKF algorithm to estimate SOC under cycle working conditions online. The results show that the improved EKF algorithm increases the estimation accuracy of the SOC of lithium batteries. Using the improved EKF algorithm, the estimated value can quickly converge to the actual value at different temperatures, and the SOC error remains within 2% in the whole estimation process.
A 3D reconstruction method for rapid warehousing and acceptance of satellite batch production lines
Authors: Zhang Yangyang , Wang Dong , Wei Peng , Qu Jiajie
Published: December 2022

The inspection of parameters such as payload flatness and interface accuracy of mass-produced satellite components is mainly completed manually by using special measuring tools. Because of its low inspection efficiency, insufficient batch inspection methods, and low degree of automation, it is impossible to continuously and stably complete high-quality inspections. Due to the shortcomings of repetitive and intelligent inspection work, a visual inspection system for fast warehousing and acceptance of satellite batch production lines based on machine vision is proposed. The multi-sensor camera is used for image acquisition, and the non-contact three-dimensional information acquisition is completed through the calculation of the three-dimensional reconstruction algorithm. The optical scanner based on multi-sensor fusion visual inspection integrates the robotic arm and the rotary table for automatic integration to realize a flexible automatic inspection scheme with seven degrees of freedom. The experimental results show that the detection system can accurately detect the size, flatness, and surface defects of satellite components in batches, and the detection accuracy can reach 0.01mm.
Application Research of Virtual Simulation System Based on Visual Tightening
Authors: Ruan Shouxin , Zhang Yiwen , Li Xin , Qi Zhengjie , Gao Yan , Yu Zhenglei
Published: December 2022

In view of the technical risks involved in the design, for development and manufacturing of visual equipment and smart equipment, factors such as long equipment development cycles were analyzed, and a truly reliable method for constructing a virtual simulation system of a virtual robot was proposed. Through the link based on OPC transmission protocol, the mechatronics MCD platform, the TIA platform, XSplit and Halcon were reorganized, and a virtual simulation system for visually guided robots was constructed for the first time in industrial production. In the real physical prototype experiment, it is recommended to eliminate the real and virtual CCD cameras through an online correction to maximize the effect of distortion. Experimental results prove that the virtual simulation system has high reliability and certain industrial promotion value.
Switch Matrix System for Automatic Test Path Finding Algorithm
Authors: He Xianzhuan , Liu Xiaolu
Published: December 2022

This paper introduces a switch matrix system that uses a configurable switch matrix to realize test channel switching. Through this configurable switch matrix system, N channels to be tested can be connected to N channels to be tested according to user requirements. Since the design of each node of the switch matrix is similar, it is convenient to expand and reduce horizontally and vertically according to the requirements. Switch Matrix adopts a double-layer design, which can obtain the optimal connection path between the tested channel and the tested channel with a path search algorithm.
Research on Grey Wolf Optimization Algorithm Based on Adaptive Adjustment Strategy
Authors: Qin Hongwu , Wang Lizheng , Sui Muxuan , Si Chunyou
Published: December 2022

A grey wolf optimization algorithm based on an adaptive adjustment strategy (Improvements-Grey Wolf Optimization, IGWO) is proposed in this paper to address the issues with the Grey Wolf Optimization (GWO) algorithm, which has a slow convergence speed in the later stages and where the local search and global search cannot be taken into effective balance. First, a chaotic logistic map is used to initialize the population. Next, an inverse trigonometric function-based mathematical model is developed to achieve convergence purposes. Finally, a new location update method is used to update the next-generation location to improve search traversability. Additionally, the CEC2013-Benchmark standard test function was used to evaluate the benefits of performance compared to the standard GWO, PSO, and DEGWO (DE-Grey wolf optimization) algorithms. The improved GWO algorithm has greatly increased the convergence speed, search capability, and stability. It performs better than the other three algorithms as well.
EEG Signal Denoising Based on Deep Residual Shrinkage Network
Authors: Zhao Haoyan , Guo Bin
Published: December 2022

In recent years, EEG signals are usually denoised by traditional algorithms, which suffer from large amounts of computation, a limited number of channels, or modal aliasing. To achieve better denoising, a deep residual contraction network is proposed to denoise EEG signals. At the same time, on the basis of the original residual shrinkage building units, a new soft threshold module is used to replace the ReLU function to construct a new network model. Through different groups of denoising experiments, the effectiveness of this denoising algorithm is verified.
Research on Servo Control Algorithm of Photoelectric Stabilized Platform Based on Sliding Mode Active Disturbance Rejection
Authors: Liu Dongmei , Tan Ligang , Guo Shuai , Qin Yingjie , Li Xuejun
Published: December 2022

Aiming at the problems of parameters to be modified and the indistinct physical meaning of the photoelectric stabilization platform control based on the principle of active disturbance rejection, a sliding mode active disturbance rejection control algorithm is proposed. The mathematical model of the control system of the two-axis optoelectronic stabilization platform is established. The external disturbance and various order states of the airborne optoelectronic stabilization platform are estimated in actual time by using the extended state observer, and the optimal control function is constructed by the sliding mode reaching law to complete the nonlinear reactive reactance. The optimization of the disturbance controller structure is carried out, and the algorithm is verified by Matlab simulation. The simulation results show that after the photoelectric stabilization platform adopts the sliding mode ADRC controller, it not only retains the advantages of strong nonlinear ADRC resistance to load disturbance, but also can effectively suppress the external disturbance and realize the high-precision position of the photoelectric stabilization platform control.
Point cloud registration method based on Particle Swarm Optimization algorithm and improved ICP
Authors: Zhu Guokai , Li Chunmei , Zhong Yuexi
Published: December 2022

In order to achieve accurate wheel gripping by truss manipulators, accurate point cloud alignment of train wheels is required. In this paper, the wheels are detected by binocular laser displacement sensors. And accurate point cloud alignment is achieved by using the point cloud denoising and streamlining algorithm, particle swarm-based algorithm, and improved ICP algorithm for 3D point cloud data. The experimental results show that reducing noise and data volume can improve the stitching effect and alignment efficiency of 3D point cloud models. The algorithm of this paper is experimentally verified to be 43% better in error accuracy and 93% faster in time-consuming than the traditional ICP algorithm, which verifies the effectiveness of its method.
Research on Surface Defect Detection Technology of Flywheel Disc Semi-Finished Products Based on Deep Learning
Authors: Shi Guangfeng , Mao Yuhang , Che Jianwei , Guan Yanji
Published: December 2022

In order to avoid the disadvantages of traditional methods such as low detection efficiency and poor detection quality, this paper designs and develops an intelligent detection system based on Faster R-CNN algorithm for the problem of detecting surface defects on the flywheel disc semi-finished products. A new network based on the ResNet50 network can better catch and describe the surface defects. Based on the k-means++ clustering analysis algorithm, the anchor generation rules are optimized. The experimental results show that the average accuracy of the optimized algorithm is improved. And the detection accuracy of small defects has been greatly improved. The feasibility and effectiveness of the optimized algorithm are verified.
Mechanical Analysis and Optimization of a new Cylindrical Splicing Clamp
Authors: Feng Yu , Wu Shaolei , Wu Kai , Han Wentao , Wang Wei
Published: December 2022

Cylindrical splicing clamp is a new type of splicing clamp designed based on a wedge-shaped self-locking principle for a 10kV distribution circuit. The clamp has the advantages of a simple structure, convenient operation, and a wide range of applicable wire diameters. In this paper, a 3D solid model of the cylindrical connecting clamp is established by using SolidWorks three-dimensional software, and then the preliminary analysis is carried out by using the Solidworks Simulation module, and the structure is improved according to the analysis results. Finally, the improved structure in ANSYS Workbench static structural module is used for finite element analysis to verify the effect of structural optimization. The results show that the structure of the optimized cylindrical splicing clamp avoids the possible problems of excessive stress concentration and uneven stress of various parts before optimization.
A new method for solving arcs of pantograph network based on Newton’s iterative method
Authors: Liu Dawei , Wang Zhe , Gao Zhiwei , Ye Zhihong , Wang Yunfeng , Zuo Shaoqi
Published: December 2022

It has been verified that the discharge pulse generated by the pantograph-catenary system has the biggest impact on the high-speed EMU as the electromagnetic interference source. But the spectrum obtained from the existing pantograph discharge model does not contain high frequencies and is far from the measurement results. In this paper, a novel scheme based on Newton’s method and finite difference time domain (FDTD) algorithm was presented to solve this problem. Firstly, Newton’s method was utilized to solve the Habedank model, and the dynamic conductance of the arc was obtained. Then, the equivalent distributed parameter circuit model of the traction power supply system was established, which was solved by the FDTD and state variable method to obtain the time-domain waveform of the arc voltage. The significant features of this scheme are that it can realize the synchronous calculations of the arc dynamic conductance and the voltage responses along the catenary. Through this scheme, a stable arc voltage time domain waveform can be obtained, and the arc voltage spectrum is highly consistent with the test results.
Design and Implementation of Pulse Diagnosis Instrument Based on Wavelet Transform
Authors: Wu Ruiqi , Xiao Jun , Zhao Fangpu
Published: December 2022

Aiming at the subjective factors in the process of TCM diagnosis, this paper designed a portable TCM pulse-diagnosis instrument. And the body state and pulse information of the user was collected by simulating the diagnosis mode of “looking, listening, questioning, and feeling the impulse”, and finally, the disease was diagnosed, and the corresponding treatment plan was proposed. STM32 is used as the main control chip, while the thin-film varistor is used as the pressure sensor to collect the pulse information of the human body. After filtering the EMG and power frequency interference by the wavelet transform algorithm, the convolution neural network algorithm is used for real-time classification and diagnosis of pulse signals to achieve the purpose of disease diagnosis. Through the experiment, it can be seen that the similarity between the pulse signal collected by the pulse detector and the ideal pulse signal is above 83%, which meets the design requirements and can realize the basic functions.
Non-intrusive closed-loop current sensor based on tunneling magnetoresistance
Authors: Deng Hui , Qian Sen , Huang Hui , Huang Feng
Published: December 2022

In this paper, a non-intrusive closed-loop current sensor based on high-sensitivity tunneling magnetoresistance (TMR) were demonstrated. Using the finite element modeling based on Maxwell’s electromagnetic theory, the distribution of magnetic field on the closed-loop magnetic flux concentrator (MFC) was calculated with a copper busbar passing through the center. Two different types with “slot” and “hole” were designed to place TMR sensors for the detection of the magnetic field generated by the working copper busbar. A secondary winding around MFC generated a reverse magnetic field to completely offset the magnetic field of the primary current, which realizes the real-time adjustment and monitoring of the current by the TMR sensor with magnetic flux balance. Moreover, the simulated results show that the performance of slot-gap MFC is better than that with hole-type design. Utilizing the experimental TMR sensor with sensitivity of 10 mV/V/Oe and linear field range of ±40 Oe, the monitoring current can reach up to 200 A. The described application in the current monitoring demonstrates the functionality and feasibility of TMR sensors.
Pressure resistance and dynamic response analysis of different magnetic blood pump base
Authors: Lu-Lu Zhao , Peng Zhou
Published: December 2022

This paper aims to explore the pressure resistance and vibration resistance performance of different magnetic blood pump base materials to help obtain the best material suitable for a centrifugal blood pump base. We establish a centrifugal blood pump model through CREO and combine it with ANSYS for simulation analysis, exploring the pressure resistance of PC, PVC, PP, PE, PA, POM, PBT, and ABS, and then the vibration resistance was investigated by dynamic response analysis. The results show that under the same conditions, pressure resistance is as follows: PVC > PE > POM > PC > ABS > PBT > PA > PP; vibration resistance is PE > PVC > ABS > PC > POM > PBT > PA > PP. PE with 2-mm thickness is the best choice of the base; at this time, the maximum deformation of the base is 0.133 mm, the maximum stress is 3.188 MPa, the first order frequency is 1311.6 Hz, and the maximum amplitude is 0.54 mm, which meets the requirements of the safety design.
A fast TDOA and VDOA estimation method of the wideband frequency hopping signal
Authors: Zhu Yi , Wu Guizhou , Guo Fucheng , Liu Zhao , Ruan Chen , Zhang Wenjun
Published: December 2022

In the mobile multi-station passive positioning scenario, the carrier frequency hopping of the wideband frequency hopping communication signal will produce a changing Doppler frequency shift. Therefore, it is not possible to directly estimate the Doppler frequency difference of the observed signal containing multiple pulses. In this case, only the time difference and frequency difference of the single-hop signal can be estimated, but the accuracy is low. The existing methods often need the carrier frequency of each FH pulse signal as a priori information, and the high computational complexity of the two-dimensional search method of the time difference and frequency difference is difficult to overcome. Aiming at the above problems, a fast and high-precision estimation algorithm for the time difference of arrival and velocity difference of wideband frequency hopping signals is proposed in this paper. Firstly, the wideband frequency hopping signal is segmented in the time domain with multiple pulses as the unit, the signal model of time-varying time difference is established, and the time difference of each short-time segment is estimated by the generalized cross-correlation algorithm. The estimated values of the initial time difference and Doppler velocity difference can be worked out by least squares fitting of the time difference sequence obtained from the single pulse estimation. Finally, taking the Link16 data link signal as an example, the simulation experiment of the proposed method is conducted, which verifies the correctness and performance superiority of the algorithm.
Experimental study on step characteristics of inchworm linear micro-actuator
Authors: Zhang Linxiang , Cao Kaihua , He Xuewen
Published: December 2022

Few studies have quantitatively analyzed the relationship among the step distance, the driving voltage, and driving frequency of the inchworm linear microactuator, which cannot achieve accurate control of the micro-actuator. What’s more, the parameter setting rule is not clear. In this paper, the relationship model among step distance, voltage, and frequency is studied through theoretical derivation and experimental analysis. The parameter setting conditions of the drive signal are analyzed, and the waveform is modified to improve the stability of the micro-actuator. The theoretical model of micro-driver step prediction is established by using the non-linear Support Vector Machine (SVM) regression theory and Gaussian radial basis kernel function and verified by experiments.
Research on the Influence of Permanent Magnet Loss of Excitation Fault on Performance of Permanent Magnet Synchronous Motor
Authors: Jiang Lu
Published: December 2022

This paper discussed the performance changes under a rated operation state and permanent magnet loss-of-field fault of a 5KW permanent magnet synchronous motor (PMSM) in a 200 mm shaftless rimless thruster. These changes in key parameters include air gap flux density, back electromotive force, output torque, current and magnetic field. Using the changes in these parameters to analyze the running state of the motor provides a reference for the early fault diagnosis of a permanent magnet synchronous motor at the simulation level.
Research on Power System Matching Scheme Design of Four-Wheel Drive Pickup Truck
Authors: Mao Lixiang , Zhang Kun , Meng Fanzhao , Li Yinuo
Published: December 2022

Automobile power matching is one of the important links in the early stage of automobile research and development, which will directly affect the performance of automobile power. According to the basic parameters and technical requirements of the four-wheel drive pickup truck, the automobile power matching scheme is designed, and the parameters of the automobile power transmission system are determined. The automobile power performance is compared and analyzed from the aspects of driving force and adhesion rate, and the optimal power system matching scheme of the four-wheel drive pickup truck is completed.
Research on Improvement of Synchronous Tensioning Device of Belt Conveyor
Authors: Bao Jihua , Feng Yibo , Liu Xiaolong
Published: December 2022

Under complex working conditions in the mines, the belt conveyor’s tensioning device is prone to uneven tension. Given this problem, the error of the shunt of synchronous motors is analyzed, and a synchronous tensioning device with double cylinders is designed by using a synchronous motor and a PID controller. Simulation analysis is carried out to verify the rationality and effectiveness of the optimization design. It can provide a corresponding reference for the design and use of the belt conveyor synchronous tensioner system.
Design of Redundant Manipulator System for Water Injection of EMU Train
Authors: Zheng Shicheng , Fu Yongling , Sun Jian , Liu Ziyu
Published: December 2022

Robots are known as "the Pearl at the top of the crown of manufacturing." As the most common kind of robot, the multi-degree-of-freedom manipulator has its reliability, lightweight, integration, and modularization, which are the focus of researchers. Based on the background of injecting water into the EMU train, this paper uses the water feeding manipulator (WFM) to completely replace the manual operation and researches the key technology of the redundant manipulator system. At the component level, a new type of planetary thread roller bearing (PTRB) is used as the main bearing component of the manipulators’ joint. For joint, two integrated joint modules (IJM) are developed based on PTRB to be an option for IJM with a high power-weight ratio and high reliability. Finally, for the system, according to the fault-tolerant performance requirements of the task point, the redundant manipulator system architecture is proposed, the mechanical body is set as the redundant structure, the driver and controller are dynamically reconstructed, and the control algorithm and fault diagnosis are fault-tolerant. The failure rate is 3.257×10-8/h, laying the foundation for the realization of a fully automatic and intelligent train water supply.
On-board Dynamic Measuring of Long-wave Track Irregularity based on Visual Inertial Fusion
Authors: Chen Shiming , Wang Hao , Li Hailang , Wei Zhongtang , Zheng Pengxu , Wei Shibin
Published: December 2022

This paper studies an inspection method to measure the long-wave track irregularities using the signals of IMU (Inertial Measurement Unit) and Laser & Camera installed on a bogie, which is implemented in comprehensive inspection trains. To reduce the influence of random noise and vehicle vibration, the mechanical structure is optimized; the spatial-dependent change of the "two-point chord" on the track is observed by high-precision FOC (Fiber Optic Gyroscope) and laser camera components; the angular velocity measurement method is deduced. To eliminate high-frequency attenuation of the signal, a sensor fusion algorithm based on the concept of complementary filters is presented. The angular velocity-based method is also used to measure low spatial frequencies, while the acceleration-based method is used to measure high spatial frequencies. The measurement accuracy of the system is evaluated from two aspects: internal and external coincidence accuracy. The test shows that the repeatability accuracy of the system to alignment and profile of the wavelength of 200 m is 0.5 mm and 0.8 mm, respectively, and the trend item and the line design value maintain good consistency.
Research on stamping forming prediction of aluminum alloy sheet based on RBF neural network
Authors: Zhao Pengjing , Yang Yo-Lun , Gao Peng , Jiao Jingpin
Published: December 2022

In order to accurately predict and reduce the possible defects in the stamping process of an aluminum alloy sheet, the simulation data of the sheet thickness for the 6016 aluminum alloy in the stamping process were obtained by the Hill’48 yield criterion based on finite element ABAQUS/Explicit solver. Taking blank holder force, friction coefficient, stamping speed, and die clearance as input parameters, the radial basis function (RBF) network model for predicting the maximum thinning rate of the stamping aluminum alloy sheet was established. The results show that the RBF network model constructed in this paper has high precision and can reflect the complex relationship between the stamping process parameters and the maximum thinning rate well by comparing the finite element simulation and neural network prediction results. It is of great significance to improve the optimization efficiency of the stamping process of the aluminum alloy sheet and reduce the actual experimental cost.
Simulation analysis and research of cylindrical lithium battery pack automation equipment system
Authors: Wang Li , Chen Hui , Ye Qian
Published: December 2022

The performance difference of the single battery has a significant impact on the cruising range, service life, charge and discharge control of an electric vehicle that uses multiple batteries as the power battery. Highly consistent performance is an essential process for lithium battery production. In order to verify the performance of the lithium battery automatic pack system, this paper used Flexsim software to establish a system simulation model, used the Dashboard data statistical method to analyze the running data of the simulation model, completed the system construction and testing, and used SPSS statistical analysis software to analyze the system test results. Using the paired sample T test, we verify that the system matching test results are accurate, that the cylindrical lithium battery matching automation equipment system has complete functions, is simple to interact with the computer, and meets the system design requirements.
Optimization Design and Simulation of Frequency Conversion and Speed Control Integrated Machine
Authors: Tian Cong , Wei Xiwen , Pang Peng , Tang Taiqing , Luo Ji
Published: December 2022

In order to realize the rapid start of equipment, the direct start method is widely used in domestic fully mechanized coal mining equipment, which forms a great starting impulse current and reduces the service life of the equipment. If a frequency converter is used to start the equipment with frequency conversion, it will face the problem of a large area and it is difficult to apply it underground. In response to this problem, the integrated variable frequency speed regulation machine studied in this paper adopts an integrated design to meet the needs of underground coal mines. The purpose of this paper is to optimize the design and simulation of the variable frequency speed control integrated machine. The experiment, which was conducted on the design of the integrated variable frequency speed regulation machine based on the optimized design, involved the experimentation and analysis of the design of the integrated variable frequency speed regulation machine for mining. Using the induction motorized structural dimension meter formula, a simulation test was conducted to compare the mining variable frequency speed regulation integrated machine with others.
Extensible Mecanum wheel intelligent car
Authors: Zhao Fanguang , Chen Congying , Chen Xiaodong , Zhang Mingyang , Yin Jie , Ren Ziqiong
Published: December 2022

Today, with the rapid development of robots, intelligent robots can bring us a lot of convenience in all aspects of life. Dangerous and difficult operations can make machines that can adapt to the changes in work tasks and working environments replace manual work. At the same time, they can also ensure personal safety, reduce labor intensity, improve labor productivity, and reduce production costs. As an intelligent mobile robot driven by multiple wheels, the intelligent car has the advantages of small size, lightweight, low cost, and convenient operation. When encountering complex terrain, it is particularly important to study the environmental adaptability and obstacle-surmounting ability of the car. The key technologies of terrain adaptability and obstacle surmounting include obstacle identification, azimuth and distance measurement, and wheel structure design.
Research on VDG Control Strategy in Hybrid Energy Storage System of Photovoltaic DC Microgrid
Authors: Zhang Jinshuo , Zhao Feng
Published: December 2022

With the access to many energy storage devices in the Photovoltaic DC microgrid, energy storage converters are also widely used, which have the characteristic of low inertia. Therefore, there are problems of low inertia in the optical storage DC microgrid system, which contains an energy storage converter, and the instability of the system causes by the fluctuation of micro-source and load mutation. In order to solve the existing problems, the paper proposes a Virtual DC Generator (VDG) control strategy based on the traditional double closed-loop control strategy in the hybrid energy storage system (HESS) of a photovoltaic DC microgrid. Applying this proposed control strategy can make the inertia and damping characteristics introduced into the converters, which provides sufficient inertia support for the optical storage DC microgrid and further improves the voltage quality. The microgrid system is modeled and analyzed based on VDG. The results show that the VDG control strategy effectively reduces power fluctuation of the hybrid energy storage and improves the stability of the microgrid system.
Life evaluation of rolling element bearings using stochastic neighbor embedding deep regression
Authors: Cheng Zhiwei , Li Xuejiao , Deng Yongsheng , Wang Xiaodan
Published: December 2022

Accurate residual service life (RSL) evaluation of rolling element bearings is significant for prognostics and health management to guarantee rotating machinery safety, availability, and efficiency. This work develops a method called stochastic neighbor embedding deep regression (SNEDR) to enhance the estimation performance of the RSL. First, the appropriate features originating from the vibration data of the tested REB are extracted. The state indicators are subsequently established with the extracted features by introducing the stochastic neighbor embedding. By doing that, the random errors and noises generated from the vibration signals can be minimized, and the evaluation performance may be improved. Finally, the regression model based on the state indicators and the long short-term memory network with time information representation capacity is generated for the RSL evaluation. The availability of the SNEDR is validated by the real data derived from a bear failure experiment. Furthermore, a peer method is introduced for a comparative study. Experimental results show that the SNEDR outperforms the competing method and can yield more reasonable and accurate evaluation results.
Path planning algorithm based on improved Bidirectional RRT
Authors: Qin Tianhao , Xin Shaojie
Published: December 2022

This paper studies the autonomous path planning of unmanned vehicles in a known driving environment. The path planning algorithm used is a hybrid algorithm combining bidirectional fast random search tree and artificial potential field method. On the basis of introducing the principle of the two algorithms, an improved algorithm combining Bi-RRT and artificial potential field is proposed. In order to reflect the advantages of the improved algorithm, the traditional RRT and Bi-RRT algorithms are simulated and compared in Matlab.
A comparative study of methods for calculating the exploitable amount of tidal energy
Authors: Ye Zhou , Gu Wenwei
Published: December 2022

As a kind of clean renewable energy, tidal current energy has a great prospect of development and utilization in China's coastal areas, but there is no unified method for evaluating tidal current energy resources. This paper firstly simulates the tidal field in Zhoushan sea based on a numerical model, analyzes the overall characteristics of tidal currents in the sea, selects the Guimen Channel with high energy density, and compares four tidal energy calculation methods, namely the Farm method, the Flux method, the Garrett method and the Lidan method, which are widely used at present, to evaluate the exploitable amount of tidal energy in the region. The results show that the results of Farm, Flux, and Lidan methods are in good agreement, while the conclusions of the Garrett method are more different from these three methods, and the differences may be related to their assumptions. The annual average current velocity in this area can reach 1.97 m/s, and the highest current velocity exceeds 4.5 m/s. The average water depth is 40 m. The exploitable tidal current energy is above 40 MW, which is suitable for large-scale installation and provides some reference for the local tidal current energy development and utilization.
A selection scheme for energy storage to participate in primary frequency regulation of new energy
Authors: Zhao Song , Li Rongli , Zhao Wei , Zhou Lei , Li Xu , Yu Haicun , Zhang Qian , Du Ronghua , Huo Hongyan , Dang Shaojia , Xin Xiaogang , Zhang Guobin , Guo Ruijun , Yin Jianhua
Published: December 2022

The choice of energy storage is the key content of the energy storage plan and design to participate in the primary frequency regulation of new energy. It involves many indicators such as safety, primary frequency modulation adaptability, economy, and environmental performance, and is a complex multi-objective decision-making problem. This paper analyses the characteristics of each index and constructs a two-level decision-making system. According to expert scores and practical application requirements, the weight of each decision-making index is obtained by the AHP method. The TOPSIS method is further used to select energy storage according to the weight of each index and related parameters.
A Load Optimization Scheduling Method of Community Energy Platform Based on Community Power Demand
Authors: Ji Xiaoheng , Lu Xueying
Published: December 2022

With the rise of electric vehicles and the increase of electric vehicle charging pile equipment in the community, the community is prone to the problems of large peak-to-valley difference and high electricity cost during the peak period of the power load. Aiming at this problem, this paper established a community energy platform model according to the different electricity load characteristics in the community. Taking the minimum difference between the peak and valley of the community electricity load and the minimum total electricity cost as the objective function, the improved constrained multi-objective particle swarm algorithm was used to optimize the scheduling of the community power system, and it was verified by an example. The results showed that by effectively regulating the output of electric vehicle charging, residential air conditioning, commercial air conditioning, and energy storage, the load peak in the community during the peak period of electricity consumption could be greatly reduced. It could effectively realize peak shaving and valley filling, reduce the cost of electricity consumption in the community, and improve economic benefits.
Research on the laws and influence factors of venting process in natural gas pipeline
Authors: Jin Wenbo , Wang Panfeng , Quan Qing , Yang Yunbo , Wang Shouxi
Published: December 2022

This paper simulates the pipeline venting process using TGNET software and proves the changing laws of venting time with pipeline venting pressure, temperature, and instantaneous flow. Moreover, the venting process with different truck-line pressure, venting-pipe diameter, venting-pipe length, and valve opening are simulated, and it is concluded that an increase in truck-line pressure and venting-pipe length will extend the venting process with venting time becomes longer and pressure drop becomes slower. While an increase in venting-pipe diameter and valve opening will speed up the venting process with venting time becoming shorter and pressure drop becoming greater.
Design of Energy-saving System for Hydraulic Scissor Lift Based on Accumulator
Authors: Gu Shiqian , Qi Guohui
Published: December 2022

The hydraulic scissor lift is a widely used special lifting equipment. In its repeated ascent and descent, the gravitational potential energy of its platform is wasted. To address this problem, a new energy-saving system based on hydraulic accumulator is proposed in this paper. A simulation model of the system is established. The simulation shows that the system can recover up to 73% of the gravitational energy while reducing the installed power of the electric motor by 60%, specifically from 5.5 kW in the baseline design to 2.2 kW in the new system. In conclusion, the proposed system can significantly improve the energy utilization efficiency of the system. This paper shows a reference for machinery similar to a hydraulic scissor lift.
Numerical Simulation of Gas-solid Jet Fire in Natural Gas Pipeline Leakage
Authors: Liu Xiao , Liu Hongtao , Zhang Quan , Zhang Xuliang , Li Ning , Wang Zhiyuan
Published: December 2022

Aiming at the problem that gas-solid two-phase jet flame formed by jet fire entrained by natural gas pipeline leakage is less studied, the gas-solid two-phase jet and pure gas-phase jet flame models formed by natural gas pipeline leakage are established by FLUENT software. The differences between the gas-solid two-phase jet and the pure gas-phase jet flame were comparatively studied, and the effect of different particle size on flame height, temperature and radiation of gas-solid jet was analyzed. The results indicate that the solid particles entering the flame will lead to a lower temperature compared to a gas-jet-only flame. The larger the mass flow of solid particles is, the lower the flame temperature of the gas-solid jet will be, and the corresponding flame height and radiation hazards are also reduced. The present study findings can be used for the purpose of studying gas-solid two-phase jet flame in leakage of natural gas pipelines.
An electrical schematic solution for superconducting fault current limiter access to the power system
Authors: Ding Wei , Jian Xianghao
Published: December 2022

High-temperature superconducting current limiters (SFCL) can suppress the short-circuit current of the power grid effectively. The 220kV and 35kV SFCL have been applied and connected to the power system in China. The 500kV SFCL equipment has been developed through the prototype and has the conditions to access the power grid. In this paper, the possible fault conditions of SFCL and the electrical scheme for connecting to the power grid are studied. The low-temperature system of SFCL is the weak point of the equipment that is prone to failure. An electrical schematic solution is proposed according to the characteristics of the SFCL equipment. This solution has the advantages of high reliability, flexibility, and convenient operation and maintenance, and it can be applied to various voltage levels of the power system.