• Volume 47,Issue 6,2024 Table of Contents
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    • >Research&Design
    • Traffic conflict risk warning method based on driving risk field

      2024, 47(6):1-7.

      Abstract (787) HTML (0) PDF 5.08 M (19857) Comment (0) Favorites

      Abstract:Urban intersections are accident-prone sections. For intelligent networked vehicles, it is very important to carry out risk detection and collision warning during driving to ensure the safety of driving. This paper proposes a traffic risk field model considering traffic signal constraints for urban intersections with traffic lights, and designs a three-level collision warning method based on this model. Firstly, a functional scenario is constructed according to the potential conflict risk points of urban intersections, and the vehicle risk field model is carried out considering the constraint effect of traffic signal. In order to solve the problem of collision warning, a three-level conflict area is proposed to be divided by the index, and the collision risk of the main vehicle is measured according to the position of the potential energy field around the main vehicle by calculating the corresponding field strength around the main vehicle. The experimental results show that the designed model can accurately warn the interfering vehicles entering the potential energy field of the main vehicle, the warning success rate can reach 100%, and the false alarm rate is only 3.4%, which proves the reliability and effectiveness of the proposed method.

    • RFID localization method based on single antenna boresight signal propagation model

      2024, 47(6):8-13.

      Abstract (488) HTML (0) PDF 5.17 M (19214) Comment (0) Favorites

      Abstract:To address the issue of low accuracy in indoor static target positioning with existing single-antenna ultra-high frequency RFID technology, this paper proposes a new RFID localization method based on an antenna boresight signal propagation model. The method first determines the height position of the target through vertical antenna scanning; secondly, it adjusts the antenna height to match that of the target and then performs stepwise rotational scanning to identify the target′s azimuth angle; furthermore, it utilizes a Sparrow Search Algorithm optimized back propagation neural network to establish a path loss model for ranging purposes; finally, it integrates the height, azimuth angle, and distance data to complete the target positioning. Experimental results show that in indoor environment testing, the proposed method has an average positioning error of 7.2 cm, which meets the positioning requirements for items in general indoor scenarios.

    • Research on dual-loop PID control system for tidal volume at high-altitude areas

      2024, 47(6):14-19.

      Abstract (471) HTML (0) PDF 2.15 M (18863) Comment (0) Favorites

      Abstract:To solve the problem of low control accuracy of the tidal volume emergency ventilation for lower air pressure at high altitudes, we propose a dual-loop PID tidal volume control system, which utilizes a pressure-compensated PID controller to adjust fan speed, supplemented by an integral-separate PID controller in order to achieve precise control of airflow velocity.Compared with single-loop PID control, the rapid response and no overshooting are observed in the performance tests of the dual-loop control system at an altitude of 4 370 m and atmospheric pressure of 59 kPa, in addition, the output error of the average airflow velocity decrease to 3.19% (the maximum error is 4.1%), which is superior to that of current clinical equipment. Our work offers an effective solution for high-altitude emergency ventilator tidal volume control, and contributes important insights to the development of ventilation control technology in special environments.

    • Research on a signal acquisition method for high-frequency measurement of underground vibration based on compressed sensing technology

      2024, 47(6):20-27.

      Abstract (339) HTML (0) PDF 8.49 M (18874) Comment (0) Favorites

      Abstract:The high-frequency measurement data of underground vibration signals can record more specific details about the dynamic response of drilling tools, which is helpful for analyzing and diagnosing abnormal vibrations underground. However, the high-frequency measurement generates a large amount of measurement data, resulting in significant storage pressure for underground vibration measurement equipment. The proposed method uses compressed sensing technology to selectively collect and store sparse underground vibration data and then recover high-frequency measurement results through a signal reconstruction algorithm. In the process of realizing this method, an innovative method of constructing a layered Fourier dictionary against spectrum leakage is proposed, and an improved OMP signal reconstruction algorithm based on layered tracking is researched and realized, which greatly reduces the time required for signal recovery. Simulation and experimental test results demonstrate the method′s effectiveness, achieving a system compression ratio of 18.9 and a reconstruction error of 52.1 dB. The proposed method may greatly reduce the data storage pressure of the measuring equipment in the underground, and provides a new way to obtain high-frequency measurement data of underground vibration.

    • Multi-session delay damage simulation based on time delay strategy

      2024, 47(6):28-33.

      Abstract (219) HTML (0) PDF 3.31 M (18731) Comment (0) Favorites

      Abstract:With the increasing demand for satellite network, vehicle-connected network, industrial network and other service simulation, this paper proposes a multi-session delay damage simulation method based on delay range strategy to build flexible software network damage simulation, aiming at the problems of small number of analog links, low flexibility and high resource occupation of traditional dedicated channel damage instruments. In this method, the delay damage of each session flow is identified and controlled independently, and the multi-queue merging architecture based on time delay strategy is adopted to reduce the resource consumption. The experimental results show that compared with the traditional dedicated device and simulation software NetEm, the proposed method supports the independent delay configuration of million-level links, increases the number of session streams from ten to one million, and reduces the memory consumption by at least 85% under each bandwidth, which meets the requirements of large scale and accuracy, and greatly reduces the system cost.

    • Design of fast capture algorithm for large frequency offset spread spectrum signal based on FPGA

      2024, 47(6):34-40.

      Abstract (391) HTML (0) PDF 8.89 M (18765) Comment (0) Favorites

      Abstract:The data bits and spread spectrum codes of the spaceborne spread-spectrum transponder are asynchronous. Due to the influence of transmission system noise and Doppler frequency shift, it can cause attenuation of peak values related to receiving and transmitting spread spectrum codes, leading to a decrease in capture performance. Traditional capture techniques often have problems such as high algorithm complexity, slow capture speed, and difficulty adapting to the requirements of large frequency offsets of hundreds of kilohertz. This article proposes a spread spectrum sequence search method that truncates the spread spectrum sequence into two segments for correlation operations, and combines the signal squared sum FFT loop for a large frequency offset locking, effectively suppressing the attenuation of correlation peaks and improving pseudocode capture performance. MATLAB simulation and FPGA board level testing show that the proposed spread spectrum signal capture scheme can resist Doppler frequency shifts of up to ±300 kHz, with an average capture time of about 95 ms. In addition, the FPGA implementation of this algorithm saves about 47% of LUT, 43% of Register, and more than half of DSP and BRAM resources compared to traditional structures, making it of great application value in resource limited real-time communication systems.

    • >Theory and Algorithms
    • Hydraulic support pressure prediction based on non-stationary differencing Transformer

      2024, 47(6):41-49.

      Abstract (444) HTML (0) PDF 10.06 M (18730) Comment (0) Favorites

      Abstract:Hydraulic support pillar pressure prediction has been a pivotal basis for decision-making in the mining process. It has been one of the fundamental pieces of information for ensuring the stability of the surrounding rock. However, although the pressure of hydraulic support pillars followed certain patterns, it couldn’t be predicted using simple mathematical models. Additionally, during the mining process, issues such as the support detaching the roof, roof fragmentation, and sensor detection errors introduced a significant amount of random noise, turning the pressure data into a non-stationary time series. This significantly complicated the pressure prediction. Based on the Transformer model, this paper proposed a differencing non-stationary Transformer model, which introduced differencing normalization and de-normalization operations in the Transformer′s Encoder and Decoder, respectively, to enhance the stationarity of the series. At the same time, a de-stationary attention mechanism was deployed within the Transformer to calculate the correlations between sequence elements, which thereby enhanced the model′s predictive capabilities. Comparative experiments on a real coal mine support pillar dataset showed that the differencing non-stationary Transformer model proposed in this paper achieved a prediction performance of 0.674, which was significantly better than LSTM, Transformer, and nonstationary Transformer models.

    • Three-dimensional indoor multi-layer structure location algorithm based on improved skyying

      2024, 47(6):50-57.

      Abstract (299) HTML (0) PDF 9.27 M (18698) Comment (0) Favorites

      Abstract:Aiming at the non-range-ranging location problem of multi-storey WSN structures, a three-dimensional indoor multi-storey structure location algorithm IAODV-HOP algorithm based on improved Tianying is proposed in the field of large-scale indoor multi-storey structure location for some large commercial supermarkets, hospitals, teaching buildings and so on. Firstly, the nodes are divided into three types of communication radius to refine the number of hops, and the average hop distance of the nodes is modified by using the minimum mean square error and the weight factor. Secondly, the IAO algorithm is used to optimize the coordinates of unknown nodes, and the population is initialized by the best point set strategy, which solves the problem that the quality and diversity of the population are difficult to guarantee due to the random distribution of the initial population in the Tianying algorithm. In addition, the golden sine search strategy is added to the local search to improve the position update mode of the population, and enhance the local search ability of the algorithm. Through simulation experiments, compared with traditional 3D-DV-Hop, PSO-3DDV-Hop, N3-3DDV-Hop and N3-ACO-3DDV-Hop, the normalized average positioning error of the proposed algorithm IAODV-HOP is reduced by 70.33%, 62.67%, 64% and 53.67%, respectively. It has better performance, better stability and higher positioning accuracy.

    • Speed tracking control of high-speed train based on BAS-PSO optimized active disturbance rejection control

      2024, 47(6):58-63.

      Abstract (317) HTML (0) PDF 2.55 M (18797) Comment (0) Favorites

      Abstract:Aiming at the Automatic Train Operation of high-speed train,an algorithm based on BAS-PSO optimized auto disturbance rejection control (ADRC) is used to design speed tracking controller.The ADRC is designed based on the train dynamics model,ITAE is used as the objective function,and the parameters are tuned by BAS-PSO.CRH380A train parameters are selected, The tracking effect of BAS-PSO, PSO and improved shark optimized ADRC algorithm on the target speed curve of the train is compared by MATLAB simulation,The tracking error of the train target speed curve based on the BAS-PSO optimized ADRC algorithm is kept in the range of ±0.4 km/h,which is closer to the target speed curve than the other two algorithms.The results show that the ADRC based on BAS-PSO optimization has the advantages of small tracking error and strong anti-interference ability.

    • Vehicle edge computing task offloading decision based on improved TD3 algorithm

      2024, 47(6):64-70.

      Abstract (424) HTML (0) PDF 4.63 M (18783) Comment (0) Favorites

      Abstract:A task offloading strategy based on Vehicle Edge Computing (VEC) is designed to meet the requirements of complex vehicular tasks in terms of latency, energy consumption, and computational performance, while reducing network resource competition and consumption. The goal is to minimize the long-term cost balancing between task processing latency and energy consumption. The task offloading problem in vehicular networks is modeled as a Markov Decision Process (MDP). An improved algorithm, named LN-TD3, is proposed building upon the traditional Twin Delayed Deep Deterministic Policy Gradient (TD3). This improvement incorporates Long Short-Term Memory (LSTM) networks to approximate the policy and value functions. The system state is normalized to accelerate network convergence and enhance training stability. Simulation results demonstrate that LN-TD3 outperforms both fully local computation and fully offloaded computation by more than two times. In terms of convergence speed, LN-TD3 exhibits approximately a 20% improvement compared to DDPG and TD3.

    • Research on registration method of infrared active target feature points under different distributions

      2024, 47(6):71-78.

      Abstract (211) HTML (0) PDF 4.99 M (18597) Comment (0) Favorites

      Abstract:Feature matching is often used to calculate pose information in visual measurement, but there is no available algorithm for designing feature matching for infrared active targets. In order to achieve matching of infrared active targets with different distributions, this paper proposes a general two-stage feature Point matching method. The first stage is coarse registration. First, the convex hull of the image feature point set is detected to obtain the outermost points. Fast coarse registration is achieved by constructing a triangle feature set and using Mahalanobis distance to calculate and search for similar triangles. The second stage is precise matching. First, the Euler angle is calculated through coarse matching features to avoid the 180° rotational symmetry of the matching results. In order to solve the problem of possible missing feature points after coarse registration, the epipolar constraint fine matching strategy is adopted to make full use of the existing features. Match the geometric information of feature points to effectively achieve accurate matching of remaining points. Theoretical analysis and experiments show that under the rotational symmetry point set and the non-rotation symmetry point set composed of 13 infrared luminescent points, this method can efficiently match within the absolute rotation range of 0°~40°, and the experimental test limit performance can reach 50°, and has good robustness to the occlusion of feature points in actual scenes. The experimental results verify its adaptability and stability, and has high practical value.

    • Improved honey badger algorithm based on elite differential variation

      2024, 47(6):79-85.

      Abstract (350) HTML (0) PDF 3.50 M (18822) Comment (0) Favorites

      Abstract:Aiming at the problems that the standard honey badger algorithm (HBA) is easy to fall into local optimum, low search accuracy and slow convergence speed, a honey badger algorithm based on elite differential mutation (EDVHBA) is proposed. The elite solution searched by the two optimization strategies in the standard HBA is combined with differential mutation to generate a new elite solution. The use of three elite solutions to guide the next iteration of the population can increase the diversity of the algorithm solution and prevent the algorithm from falling into premature convergence. At the same time, the nonlinear density factor is improved and a new position update strategy is introduced to improve the convergence speed and optimization accuracy of the algorithm. In order to verify the performance of the algorithm, simulation experiments are carried out on eight classical test functions. The results show that compared with other swarm intelligence algorithms and improved HBA, EDVHBA can find the optimal value 0 in the unimodal function, and converge to the ideal optimal value in the multimodal function after about 50 iterations, which verifies that EDVHBA has better optimization performance.

    • >Information Technology & Image Processing
    • Near-shore ship target detection in large scene SAR images based on CAM-YOLOX

      2024, 47(6):86-93.

      Abstract (513) HTML (0) PDF 10.47 M (19009) Comment (0) Favorites

      Abstract:A lightweight improved model CAM-YOLOX is designed based on YOLOX to address the issues of false alarms of land targets and missed detections of shore targets encountered in ship target detection in large scene Synthetic Aperture Radar(SAR)images in near-shore scenes. Firstly, embed Coordinate Attention Mechanism in the backbone to enhance ship feature extraction and maintain high detection performance; Secondly, add a shallow branch to the Feature Pyramid Network structure to enhance the ability to extract small target features; Finally, in the feature fusion network, Shuffle unit was used to replace CBS and stacked Bottleneck structures in CSPLayer, achieving model compression. Experiments are carried out on the LS-SSDD-v1.0 remote sensing dataset. The experimental results show that compared with the original algorithm, the improved algorithm in this paper has the precision increased by 5.51%, the recall increased by 3.68%, and the number of model parameters decreased by 16.33% in the near-shore scene ship detection. The proposed algorithm can effectively suppress false alarms on land and reduce the missed detection rate of ships on shore without increasing the number of model parameters.

    • Research on adaptive ORB-SLAM2 algorithm in dark environments

      2024, 47(6):94-99.

      Abstract (230) HTML (0) PDF 8.72 M (18792) Comment (0) Favorites

      Abstract:A feature point extraction algorithm based on adaptive threshold and an improved quadtree homogenization strategy are proposed to address the issue of low positioning accuracy or low matching logarithms of the SLAM system caused by the ORB-SLAM2 algorithm extracting fewer feature points in dark environments or environments with fewer textures, resulting in system crashes. Firstly, based on the brightness of the image, FAST (Features from Accelerated Seed Test) feature points are extracted using adaptive thresholds. Then, an improved quadtree homogenization strategy is used to eliminate and compensate the feature points of the image, completing feature point selection. The experimental results show that the improved feature point extraction algorithm increases the number of matching pairs by 17.6% and SLAM trajectory accuracy by 49.8% compared to the original algorithm in dark and textured environments, effectively improving the robustness and accuracy of the SLAM system.

    • Saw chain defect detection system based on low-light enhancement and YOLO algorithm

      2024, 47(6):100-108.

      Abstract (376) HTML (0) PDF 12.61 M (18958) Comment (0) Favorites

      Abstract:In real-time detection of saw chain defects based on machine vision, factors like oil contamination and dust impact image brightness and quality, leading to a decrease in the feature extraction capability of the object detection network. In this paper, an automated saw chain defect detection method that combines low-light enhancement and the YOLOv3 algorithm is proposed to ensure the accuracy of saw chain defect detection in complex environments. In the system, the RRDNet network is used to adaptively enhance the brightness of the saw chain image and restore the detailed features in the dark areas of the image. The improved YOLOv3 algorithm is used for defect detection. FPN structure is added with a feature output layer, the a priori bounding box parameters are re-clustered using the K-means clustering algorithm, and the GIoU loss function is introduced to improve the object defect detection accuracy. Experimental results demonstrate that this approach significantly improve image illumination and recover image details. The mAP value of the improved YOLOv3 algorithm is 92.88%, which is a 14% improvement over the original YOLOv3. The overall leakage rate of the system eventually reduces to 3.2%, and the over-detection rate also reduces to 9.1%. The method proposed in this paper enables online detection of saw chain defects in low-light scenarios and exhibits high detection accuracy for various defects.

    • >Online Testing and Fault Diagnosis
    • Research on monitoring and predicting method of residual life of wireless SPD

      2024, 47(6):109-115.

      Abstract (304) HTML (0) PDF 6.31 M (18818) Comment (0) Favorites

      Abstract:In order to solve the problems that the traditional SPD life alarm characterization method can not clearly correspond to the real life state of SPD, and the remaining life model characterized by a single degradation related parameter has poor predictability, a multi-parameter SPD life remote monitoring system based on STM32 is designed. With STM32 as the main controller, the important parameters such as surge current, leakage current, surface temperature and tripping status of SPD are collected in real time, and the status information is uploaded to the One net cloud platform through the BC20 wireless communication module. The One net cloud platform displays and stores the multi-parameter data of SPD in real time, and provides data management and analysis. The SVM classification model is used to judge whether SPD is damaged and the BO-LSTM prediction model is used to predict the remaining life of SPD. Based on the positioning function of BC20, the real-time geographic location of SPD can be viewed on the host computer. The results show that the root mean square error and average absolute error of the BO-LSTM prediction model are 0.001 3 and 0.001 8, and the system can monitor the SPD status in real time, effectively predict the remaining life value of SPD, and give early warning in time.

    • Fault diagnosis of rolling bearings based on EEMD energy entropy and GJO-KELM

      2024, 47(6):116-122.

      Abstract (429) HTML (0) PDF 6.40 M (18777) Comment (0) Favorites

      Abstract:Rolling bearings play an important role in rotating machinery. If a fault occurs, it can cause equipment shutdown, and in severe cases, endanger the safety of on-site personnel. Therefore, it is necessary to diagnose the fault. In response to the difficulty in extracting fault features of rolling bearings and the low accuracy of traditional classification methods, this paper proposes a fault diagnosis method based on Set Empirical Mode Decomposition (EEMD) energy entropy and Golden Jackal Optimization Algorithm (GJO) optimized Kernel Extreme Learning Machine (KELM), achieving the goal of extracting fault features of rolling bearings and correctly classifying them. Through experimental data validation, this method can extract the fault information features hidden in the original signal of rolling bearings, with a diagnostic accuracy of up to 98.47%.

    • Design and research on expert system for abnormal data detection in low-speed pressurized wind tunnel force test

      2024, 47(6):123-130.

      Abstract (309) HTML (0) PDF 7.06 M (18838) Comment (0) Favorites

      Abstract:Aiming at the force test in low-speed pressurized wind tunnel, the original data source of aerodynamic characteristic curve is analyzed. With the balance signal, flow field state and model attitude as the main objects, combined with the test control process, the abnormal detection methods and strategies of the test data are studied from the dimensions of single point data vector, single test data matrix and multi-test data set in the same period, and an expert system for abnormal data detection is designed and developed based on this core knowledge base. The system inference engine automatically detects online during the test, and realizes the pre-detection and pre-diagnosis of the original data through data identification, rule reasoning, logical reasoning and knowledge iteration. The experimental application results show that the expert system is highly sensitive to the detection of abnormal types such as abnormal bridge pressure, linear segment jump point and zero point detection, which guides the direction of abnormal data analysis and improves the efficiency of problem data investigation.

    • >Data Acquisition
    • High-precision long-displacement sensor based on axial eddy current effect

      2024, 47(6):131-136.

      Abstract (169) HTML (0) PDF 2.09 M (18599) Comment (0) Favorites

      Abstract:In order to realize high-precision real-time detection of large-stroke precision optical focusing components In order to realize high-precision real-time detection of large-stroke precision optical focusing components, high-precision long-displacement sensors based on axial eddy current effect are studied. A long-displacement eddy current probe simulation model is established for linearity testing, an eddy current sensor test system is built for accuracy experiments, and the long-displacement eddy current sensor is connected to the precision optical focusing assembly. The experimental results show that while the measurable displacement reaches 24 mm, the linearity is better than 1%, the resolution is better than 0.5 μm, the accuracy is better than 1 μm, and the high-precision long-displacement eddy current sensor meets the requirements of the precision optical focusing assembly.

    • Design and measurement uncertainty analysis of cigarette heating rod thermometer

      2024, 47(6):137-142.

      Abstract (349) HTML (0) PDF 4.14 M (18737) Comment (0) Favorites

      Abstract:For the tobacco industry, there is currently no detection device and method for detecting the heating temperature and temperature uniformity of heated cigarette smoking sets. In order to solve the temperature measurement needs of micro rod-shaped heating sheets in a narrow space, this article developed a cigarette heating rod thermometer, and designed a new structure suitable for temperature measurement of cigarette heating rods. In order to verify the accuracy and reliability of the measurement results of the cigarette heating rod thermometer, uncertainty analysis of the thermometer was performed. The analysis results are based on the "GB/T 13283-2008 Accuracy Level of Detection Instruments and Display Instruments for Industrial Process Measurement and Control" standard. The measurement range is 100 ℃~400 ℃, meeting the requirements of level 0.1. The final experiment verified that the heating temperature field of different cigarettes can be effectively measured.

    • Research on the leak detection of directly buried heating pipe network by an improved threshold function

      2024, 47(6):143-150.

      Abstract (279) HTML (0) PDF 5.54 M (18691) Comment (0) Favorites

      Abstract:To improve the positioning accuracy of the leakage application of the direct buried hot water heating pipe network by acoustic method, based on the analysis of the applicability of various wavelet threshold functions, an improved threshold function noise reduction method is proposed. This method can theoretically overcome the constant deviation of the soft threshold function and the shortcomings of the hard threshold function signal oscillation. Through setting adjustment parameters, improving the noise reduction ability, and retaining the signal of the region less than the threshold point to avoid effective signal loss. The experiment was carried out in a large direct buried hot water circulation pipe network. The research showed that the leakage positioning error was within ±1 m and the positioning accuracy reached 0.11%~3.49%. Finally, the acoustic leakage detection method was adopted in a practical engineering case of a Beijing heating system. The leakage location error is 0.37%~0.66%, and the positioning accuracy has efficiently is improved.

    • Simulation and optimization of ultrasonic phased array full-focus imaging for pipes

      2024, 47(6):151-156.

      Abstract (478) HTML (0) PDF 10.26 M (18634) Comment (0) Favorites

      Abstract:Ultrasonic phased array theory and Total Focusing Method are introduced to identify internal defects of thick-walled pipelines,the image is reconstructed. Sparse Matrix Capture technology is used to reduce data volume and improve imaging efficiency, it simulated the ultrasonic phased array total focus imaging of thick-walled pipelines with the outer diameter of 550mm and the wall thickness of 65 mm by the finite element method. The results show that when the excitation center frequency is 5 MHz, the element width is 0.5 mm, the element spacing is 1 mm, the number of array elements is 32. the effectively of the image of Sparse Matrix Capture-Total Focusing Method is 74.81% higher than that of Full Matrix Capture-Total Focusing Method, which is improves the imaging speed and meets the requirements of rapid imaging.

    • Lightweight audio signal processing algorithm and FPGA implementation

      2024, 47(6):157-163.

      Abstract (327) HTML (0) PDF 10.53 M (18591) Comment (0) Favorites

      Abstract:In order to solve the problem that the audio signal processing in the voice communication system has a large amount of data, a lot of stray signals, and the received audio signals of the frequency modulation receiver are large and small, a lightweight audio signal processing algorithm is proposed, and based on this algorithm, the audio signal receiving and automatic gain control are realized on the field programmable gate array(FPGA) platform. The algorithm combines digital downconversion technology, multistage extraction filtering technology and automatic gain control technology (AGC) technology, and is applied to the audio signal processing system. The RF analog signal received from the upper antenna is converted into baseband audio signal through analog-to-digital conversion and digital down-conversion, and the stray signal in the baseband signal is filtered through four-stage extraction filtering, reducing the complexity and power consumption of the system. At the same time, the digital AGC controls and adjusts the baseband audio signal to output a more stable audio signal. The experimental results show that the algorithm can effectively reduce the information rate from 102.4 MHz to 32 kHz, reduce the computation burden, improve the signal quality, and reduce the resource utilization of FPGA. And the automatic gain control adjustment of audio signal is realized, and the adjustment time is only 12.8 μs, which meets the power stability time of the receiver.

    • Enhanced LORAN signals generating based on cycle-consistent adversarial networks

      2024, 47(6):164-172.

      Abstract (324) HTML (0) PDF 5.66 M (18696) Comment (0) Favorites

      Abstract:In signal generation algorithms, a large number of labeled signal samples are needed for network training, but it is usually difficult to obtain signals carrying message information markers in bulk. To address this problem, this paper proposes a method based on CycleGAN and transfer learning, which realizes the generation of Enhanced LORAN signals without the need for a large number of signals and the corresponding messages as markers and uses migration learning to generate them quickly with a small number of measured signals. The structure of the CycleGAN includes two generators and two discriminators, using the Enhanced LORAN signals and message data sets that do not need to be one-to-one correspondence, so that the generator learns the interconversion relationship between the two data sets, and realises that the input message data can generate the Enhanced LORAN signals corresponding to it, for the characteristics of the Enhanced LORAN signal, the network model is improved using a one-dimensional convolution, residual network, and self-attention mechanism. Experimentally confirmed, it is confirmed that the mean square error of the signal generated by this paper with the measured data is 0.015 3, the average Pearson correlation coefficient is 0.984 3, and the accuracy of the contained message information is 99.02%. To verify the universality of the algorithm, this paper validates the algorithm on PSK, ASK, and FSK datasets, and the experimental results show that the generated signals satisfy the expectations and provide a new idea for signal modulation and demodulation with unknown parameters.

    • Few-shot font generation for multilevel channel attention networks

      2024, 47(6):173-181.

      Abstract (370) HTML (0) PDF 5.25 M (18665) Comment (0) Favorites

      Abstract:In order to improve the image quality of font generation and reduce the labour cost of font design, a method for few-shot font generation based on multilevel channel attention network is proposed. Firstly, the method acquires important local features through the style-aware attention module; then a multilevel attention mechanism is designed, where shallower layers can only observe the local features of the image, while deeper layers can observe all the features of the image, and new stylistic features are constructed by aggregating the local features of different levels. Finally, a content loss function, a style loss function and a L1 loss function are used to optimise the parameters of the model and stabilise the training of the network so that the generated images are consistent with the target font in terms of content and style. The experimental results show that the method has a strong generalisation to fonts of unknown style and fonts of unknown content. Compared to other methods, the proposed method shows better experimental results that maintain the integrity of the content structure and the accuracy of the font style.

    • Design of dynamic tracking platform for unmanned aerial vehicle based on Raspberry Pi 4B

      2024, 47(6):182-189.

      Abstract (350) HTML (0) PDF 7.48 M (18685) Comment (0) Favorites

      Abstract:Facing the challenges of regulating unmanned aerial vehicles (UAV), and based on an YOLOv5-Lite improved model, this paper incorporates an exponential moving sample weight function that dynamically allocates loss function weights to the model during the training iteration. Through model computations, we achieve real-time UAV tracking using a two-degree-of-freedom servo platform. Furthermore, video capture, model calculations, and servo control are all performed locally on a Raspberry Pi 4B.The optimized model maintains the original model's parameter count while achieving a mAP@.5:.95 score of 70.2%, representing a 1.5% improvement over the baseline model. Real-time inference on the Raspberry Pi yields an average speed of 2.1 frames per second (FPS), demonstrating increased processing efficiency. Simultaneously, the Raspberry Pi controls a servo platform via the I2C protocol to track UAV targets, ensuring real-time dynamic monitoring of UAVs. This optimization enhances system reliability and offers superior practical value.

    • Research on sEMG gesture recognition algorithm based on TiCNN-DRSN model

      2024, 47(6):190-196.

      Abstract (313) HTML (0) PDF 6.77 M (18714) Comment (0) Favorites

      Abstract:The gesture recognition method based on surface electromyography and pattern recognition has a broad application prospect in the field of rehabilitation hand. In this paper, a hand gesture recognition method based on surface electromyography (sEMG) is proposed to predict 52 hand movements. In order to solve the problem that surface EMG signals are easily disturbed and improve the classification effect of surface EMG signals, TiCNN-DRSN network is proposed, whose main function is to better identify the noise and reduce the time for filtering the noise. Ti is a TiCNN network, in which convolutional kernel Dropout and minimal batch training are used to introduce training interference to the convolutional neural network and increase the generalization of the model; DRSN is a deep residual shrinkage network, which can effectively eliminate redundant signals in sEMG signals and reduce signal noise interference. TiCNN-DRSN has achieved high anti-noise and adaptive performance without any noise reduction pretreatment. The recognition rate of this model on Ninapro database reaches 97.43% 0.8%.

Editor in chief:Prof. Sun Shenghe

Inauguration:1980

ISSN:1002-7300

CN:11-2175/TN

Domestic postal code:2-369

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