NetWork
Virtual-physical integrated experimental platform for oil storage control based on data-driven modeling
YAN Yong;LIU Xuejun;LI Zhonglin;SHA Yun;ZHANG Wenchang;WANG Rumo;[Objective] In the process of intelligent transformation within the petroleum and petrochemical industry， the penetration rate of artificial intelligence technologies in industrial control systems has surged. The deep security defense system is now facing severe challenges from polymorphic attacks such as adversarial attacks on AI models， with security incidents occurring frequently. This has led to a dramatic increase in the demand for composites who are proficient in both artificial intelligence and industrial control security， posing new requirements for talent cultivation in industry-related universities. In particular， there is a pressing issue of the lack of an industrial control security experimentation platform that balances both flexibility and reliability. [Methods] Based on the cultivation of composite personnel's talent capabilities in system analysis， we draw on physical entities， virtual entities， services， twin data and five-dimensional models connecting five dimensions to conduct in-depth analysis of the real oil storage system business processes， abstract the core typical business processes， so that each module can simulate the normal and abnormal situations of the main core businesses in the real scenarios of oil storage warehouses of different scales. On the basis of comprehensively reflecting the system control logic， considering the requirements of model safety， durability， stability and reliability， an oil storage control system safety architecture and simulation experiment platform solution are constructed that combine real hardware equipment and simulation models. A dynamic physical model platform for the oil tank level-flow coupling system of the oil storage control system was designed and built， and a digital twin model with adaptive parameter correction capabilities was constructed based on multivariable system identification and machine learning algorithms. The platform is based on the SCADA system configuration protocol to the principles of OPC UA data service to the application closed loop. The middle platform realizes dual-drive feature extraction of equipment mechanism and data. The upper layer relies on the virtual debugging environment to establish an intelligent oil storage optimization control system based on nonlinear model prediction control through feature extraction and transfer learning of on-site operation data. [Results] Based on this platform， five types of experiments have been designed: Core business data acquisition experiments in typical scenarios， attack data generation experiments， data preprocessing AI algorithm experiments， data generation and prediction AI algorithm experiments， and AI anomaly detection model experiments. Students deeply understand the industrial control system architecture， use the control of the valve opening of the oil storage system and adjust the different operating states of the pump， simulate the core business of typical scenarios in the oil collection process， storage process， and oil generation process of oil depots of different sizes， and complete normal business data collection. Later， the attacks targeting the host computer and controller are designed to collect attack data， clean and preprocess the data， and use 4 byte hexadecimal format to mark the data to form a data set. On this basis， experiments such as intelligent sensing data enhancement and generation， equipment health assessment based on time-series pattern mining， abnormal diagnosis of multi-source heterogeneous data， situation awareness， and security protection are carried out. [Conclusions] This research innovatively establishes a hierarchical and progressive experimental teaching system of "modeling development - algorithm verification - scenario migration". The three-layer progressive cultivation mode adopts an intelligent security verification method integrating virtual and real scenarios， strengthens the systematic training mechanism of systematic modeling development - adaptive algorithm optimization - full operating condition migration and iteration， and focuses on cultivating students' practical ability to integrate technologies such as artificial intelligence， industrial control security protection， and digital twin to solve the security problems of complex systems in the field of industrial control.
Development and Experimental Research of Resistance Additive Manufacturing Equipment
WANG Wenqin;HAN Zhiyang;HUANG Wei;CHEN Jigen;XU Yongdong;WANG De;Addressing the prevalent issues of high costs， operational complexity， and thermal stresses associated with traditional high-energy beam additive manufacturing techniques， such as those utilizing lasers， researchers have introduced groundbreaking resistance additive manufacturing equipment based on resistance seam welding technology. This innovative approach presents a novel solid-phase additive manufacturing method that stands out due to its cost-effectiveness， reduced material consumption， operational simplicity， and minimized thermal input. It effectively facilitates the production of WC-AlCoCrFeNi_(2.1) cemented carbide by employing the AlCoCrFeNi_(2.1) eutectic high-entropy alloy as a binder. To optimize the production of WC-AlCoCrFeNi_(2.1) hard alloys via resistance additive manufacturing， a series of orthogonal experiments were conducted. These experiments aimed to analyze the influence of various factors on the surface roughness and microhardness of the manufactured alloys. The research identified that the optimal process parameters are a welding pressure of 0.4 MPa， a welding current of 5 kA， and a welding speed of 2 mm·s~(-1). Under these conditions， the resulting structure exhibited high stability and minimal defects， indicating the effectiveness of these parameters in achieving high-quality results. Additionally， the impact of WC powder particle size on the surface roughness and microhardness of the resistance additive samples was thoroughly investigated. The findings revealed that a reduction in the particle size of WC powder led to significant improvements in surface finish. Specifically， when the WC powder particle size was reduced to less than 5 μm， the surface of the produced alloy became notably smoother and more uniform. This refinement in surface quality was accompanied by a substantial increase in average microhardness， which reached up to 1 911.2 HV_(0.1). These results highlight the benefits of using finer WC powders， particularly those with particle sizes below 5 μm， for achieving superior results in resistance additive manufacturing. Furthermore， the study included a comparative analysis of the performance of WC-10%AlCoCrFeNi_(2.1) hard alloy produced through resistance additive manufacturing against the traditional WC-10%Co hard alloy. This comparison focused on critical mechanical properties， including hardness and elastic modulus. The results demonstrated that the WC-10%AlCoCrFeNi_(2.1) alloy exhibited significantly superior hardness compared to the WC-10%Co alloy， with notable improvements of 32.1%， 0.9%， and 28.6% in the xz， xy， and yz directions， respectively. Additionally， the elastic modulus of the WC-10%AlCoCrFeNi_(2.1) alloy was found to be higher， with average increases of 14.2%， 3.7%， and 20.2% in the xz， xy， and yz directions， respectively. These findings of this study demonstrate the potential of RSAM technology as a viable and advantageous approach for producing high-performance WC-based cemented carbides. By employing AlCoCrFeNi_(2.1) eutectic high-entropy alloy as the binder phase， this method exhibits superior cost-effectiveness， environmental friendliness， and production efficiency compared to conventional manufacturing processes. Notably， the implications of this research extend beyond cemented carbides. The demonstrated adaptability of RSAM to various material systems - including ceramics， intermetallics， and multi-principal element alloys - suggests new possibilities for fabricating advanced hard alloys and other high-performance materials. These achievements establish a robust foundation for subsequent studies on process optimization， multi-material fabrication， and industrial applications， with anticipated impacts on innovation in additive manufacturing and materials science.
Virtual simulation of motor heat transfer characteristics under different working duty cycles
ZHU Gaojia;CHEN Hongjiang;LI Longnü;WANG Youzheng;SHI Boya;ZHU Jianguo;MEI Yunhui;[Objective] During the long-term operation of electrical machines， damage caused by overheating is a critical concern. As a result， enhancing thermal analysis and thermal design capabilities has become a focal point for researchers and manufacturers. The course Electrical Machine Design has been developed to equip students with the skills and knowledge necessary for professional careers in machine design. A key component within this course is the Temperature Rise Analysis section， which is dedicated to the thermal analysis and management of electrical machines. However， traditional teaching methods predominantly focus on continuous-duty cycles in thermal analyses (S1)， while other kinds of cycles are often overlooked. The complex dynamic heat transfer processes involved in the impact of duty cycles on temperature rises are challenging to visualize and have emerged as a significant hurdle in effective teaching. [Methods] To overcome the limitations of traditional teaching methods in conveying in-depth concepts and illustrating dynamic processes， this study proposes an innovative teaching strategy based on two core approaches: (1) understanding of the in-depth mechanism and (2) intuitive visualization through virtual simulation. For the former， the study dissects the intrinsic mechanisms of dynamic heat transfer in electrical machines， enabling students to comprehensively grasp the theoretical foundations of thermal equilibrium establishment and its key characteristics. For the latter， a virtual simulation platform is developed to analyze temperature rise characteristics and distributions under three typical duty cycles (S1–S3). This platform provides an intuitive perspective that helps students understand the evolution and stabilization of machines’ temperature rises under different duty cycles. [Results] Under the three duty cycles， the initial rate of temperature rise is uniform. This uniformity stems from the fact that in the initial phase， the involved machine starts from an ambient temperature and operates at rated power. Consequently， the heat generation and external heat dissipation conditions are identical across these cycles， leading to consistent thermal characteristics. Under the S1 continuous-duty system， the machine operates at rated power until thermal equilibrium is achieved， with the temperature rise increasing steadily until it reaches a steady-state value. In contrast， under the S2 and S3 intermittent-duty systems， the machine’s intermittent operation enhances heat dissipation and reduces heat generation， preventing the temperature rise from reaching the steady-state level. Thus， the S1 system reflects the maximum temperature rise during long-term motor operation without overload. Further， simulation analysis of the machine’s temperature distribution under the S1 system can effectively assess its long-term operational reliability. Moreover， machines designed for cooling under the S1 system can operate with reduced cooling requirements or increased load when used under the S2 and S3 systems due to the lower temperature rise. Conversely， when an electrical machine designed for cooling under the S2 and S3 systems operates under the S1 system， it is necessary to reduce the load or enhance external cooling conditions to prevent overheating. [Conclusions] Practical experiences with the teaching method demonstrate that the involved theoretical investigations can provide students with efficient in-depth understanding and that the virtual simulation platform effectively visualizes the dynamic process of motor temperature rise. The combination of the two methods aids students in understanding complex heat transfer mechanisms and significantly enhances their comprehension of challenging knowledge points. Furthermore， this approach fosters students’ ability to apply fundamental mathematical and engineering principles to solve complex engineering problems. By stimulating students’ interest in the intricate theories of electrical machine design， this teaching method also nurtures their innovative thinking and engineering practice capabilities， offering valuable insights for reforming the course Electrical Machine Design.
Electromagnetic design and magnetothermal performance simulation of a 400 Hz large-capacity low-voltage dual-split medium-frequency transformers
TIAN Fengqi;DU Zhenbin;WANG Youhua;WANG Jianmin;SHI Jian;[Objective] At present， the medium frequency transformer (MFT) is one of the key equipment of offshore wind power systems; however， the design and manufacturing technology of high-voltage large-capacity MFTs is not yet mature. At the same time， the increase in frequency and capacity significantly changes the electrical performance and structural characteristics of the MFT， resulting in a more prominent magnetothermal problem. Therefore， to ensure the safe and stable operation of the MFT and prevent the risk of local overheating， this paper uses the electromagnetic design theory and the parameter scanning method to design a 125 MVA/241 kV single-phase large-capacity low-voltage double-split MFT; the magnetic field， loss， and temperature field distributions of the MFT are calculated and analyzed by using a finite-element software. [Methods] First， the initial electrical design scheme of a 400 Hz MFT at the 125 MW level， which meets the basic technical conditions of the product， was developed. Second， to verify the accuracy of the design results， the three-dimensional electromagnetic and temperature coupling calculation model of the MFT was established using MagNet software; the magnetic characteristic curves of the silicon steel used for the core were measured at frequencies of 400 Hz and 50 Hz. Then， the electrical conductivity of the simplified winding was modified. At the same time， the short-circuit impedance was verified using the specialized software MF2D， thereby validating the reasonableness of the calculation method and the results. Third， the magnetic field and loss distribution of the MFT under no-load and load conditions were calculated and analyzed， and the temperature field distribution of the transformer metal structural parts was simulated through magnetothermal coupling by using ThermNet and MagNet software. At the same time， the hot spots of the core and the winding were obtained through the two-dimensional fine modeling and simulation calculation of the transformer winding. The magnetothermal distribution showed that the no-load loss of the core was large， leading to the risk of local overheating. Finally， to reduce the core loss and prevent local overheating， the local overheating control was conducted by increasing the number of core oil channels. [Results] The results show the following: First， by comparison with the power frequency transformer， it is found that the total weight of the MFT is reduced by 43.3%， the main magnetic flux density is reduced by 57.6%， and the load loss is reduced by 18.83%; however， the no-load loss is increased by about 1.85 times because of the increase in frequency. Second， the short- circuit impedance obtained by the magnetic field energy method is compared with the calculated value of MF2D， and the overall difference is less than 4.0%. The difference between the total loss of the MFT calculated by MagNet and the design value is 2.9%. Third， the simulation analysis of the magnetothermal coupling performance of the MFT shows that the temperature rise of the core has exceeded the temperature rise limit of 80 K specified in the product design requirements. It can be seen that the analyzed transformer has the risk of local overheating. Compared with the model without an oil channel， the hot spot temperature rise of the models with single， double， and triple oil channels decreased by 28.85%， 41.18%， and 38.97%， respectively. Finally， a double oil passage structure is determined. [Conclusions] The simulation results show that the magnetothermal coupling performance of the high-capacity and high-voltage MFT designed in this paper meets the requirements of the product design， which will provide a reference to the magnetothermal coupling design of MFTs in the future.
with magnetic gradient tensor invariants
WANG Shuocheng;LIU Zhaoting;LI Ran;HUANG Ying;[Objective] Presently， magnetic target detection technology has found extensive application prospects in various fields， such as unexploded ordnance detection and moving-object tracking. However， existing single-point positioning methods are susceptible to interference from background magnetic fields and rely heavily on high-precision sensors. In addition， multipoint positioning methods face the challenges of local optimal solutions and substandard real-time performance. [Methods] To overcome the aforementioned bottleneck， this paper proposes a two-point localization framework that integrates magnetic gradient tensor invariants with a modified starfish optimization algorithm (mSFOA). The proposed method uses an orthogonal array of four sensors (baseline: 0.5 m) to acquire magnetic gradient tensor data at two spatially separated observation points. This configuration allows differential measurements to suppress ambient noise. An optimization model of the objective function is developed based on the magnetic dipole-closed one-point localization formula， which is based on magnetic gradient tensor invariants. The optimization model is constructed because the magnetic moment of the target to be localized is invariant at two adjacent measurement points. The spatial relationship of the geometric invariant of the magnetic gradient tensor is introduced， whereby the distance vector from the measurement point to the magnetic dipole position is coplanar with the eigenvectors corresponding to the maximum and minimum eigenvalues; concurrently， the eigenvectors corresponding to the smallest absolute eigenvalue are perpendicular to the distance vector as the constraint term. Then， the mSFOA is used to process the optimization function. Three improvements are made to the algorithm. These improvements solve the problem of the premature convergence of traditional starfish optimization algorithms. In conclusion， the spatial position coordinates of the target are obtained by solving the objective function using the mSFOA. [Results] In this study， the positioning error is considered as an observable. The inspection experiment of the translational motion of the detection system and the tracking experiment of the localized moving target are designed to verify the performance of the proposed optimization model and the improved optimization algorithm. The experimental results demonstrate that the proposed method exhibits an average positioning error of only 0.99 m， with an overall variance of 0.27 m~(2). This performance metric is notably superior to those of other single-point and multipoint localization methods， as evidenced by the uninterrupted measurement along the system trajectory over a duration of 20 s. This demonstrates the efficacy of the proposed optimization model and the enhanced optimization algorithm， substantiating the ability of the proposed method to accurately localize a magnetic target. [Conclusions] The positioning of magnetic targets by the proposed method has been demonstrated to be an effective solution to the problem of single-point positioning being susceptible to interference and multipoint positioning being unstable. Through the combination of geometric invariants and the enhanced metaheuristic algorithm， the proposed method achieves high accuracy and stability in a magnetic target detection environment. The results demonstrate that the proposed methodology attains its intended objective and considerably enhances the precision of magnetic target positioning.
Experimental calibration-based study of bearing design for curved bridges with variable pier heights
JIAO Chiyu;ZHOU Jiaxin;LI Yangjie;HE Peijian;[Objective] Curved girder bridges with variable pier heights and small curvature radii are widely adopted in modern transportation infrastructure due to their adaptability to complex terrain and urban landscapes. However， this irregular spatial configuration significantly increases their mechanical complexity under seismic loading. Post-earthquake investigations， such as those following the devastating earthquakes in regions like Japan and California， have demonstrated that these geometric characteristics substantially elevate structural vulnerability. The curvature-induced centrifugal forces， combined with the differential displacements caused by varying pier heights， often lead to concentrated damage at critical components， including pier bases and bearings. As such， the optimization of bearing configurations emerges as a crucial strategy for mitigating seismic responses in these geometrically complex bridges， aiming to enhance structural integrity and safety during seismic events. [Methods] This investigation centers on a prototype 4×20m concrete curved bridge with a 50m radius. To accurately assess its seismic performance， the bridge was scaled down to 1/20 through meticulous dimensional analysis for shaking-table testing. The scaled model was subjected to a series of dynamic loading scenarios， simulating real-world seismic conditions. Concurrently， a refined finite element model was developed using advanced engineering software. This model was rigorously validated against the experimental results， ensuring its reliability for further analysis. This validation process allowed for a comprehensive comparative analysis of seismic performance across different pier-girder connection systems. Three distinct intermediate pier configurations were then systematically examined through nonlinear time-history analysis under bidirectional seismic excitation， enabling a detailed exploration of their dynamic responses and failure mechanisms. [Results] For four-span curved bridges with height-varying piers， the intermediate pier bearing configuration exerts a pivotal influence on global seismic performance， especially when transition piers utilize unidirectional sliding bearings. Numerical simulations， supported by detailed data analysis， reveal that the proposed hybrid system， which combines sliding bearings at tall/medium piers with fixed bearings at short piers， demonstrates superior mechanical behavior compared to conventional fully-fixed configurations. Specifically， the hybrid system reduces pier-bottom moment peaks by up to 35% and shear force peaks by 30% through optimized force redistribution. Despite these significant reductions in internal forces， it maintains comparable displacement control capacity. Notably， the hybrid configuration effectively mitigates moment concentration at critical pier bases and constrains structural displacements within operational thresholds， significantly enhancing the bridge’s capability to prevent girder unseating during extreme seismic events. [Conclusions] Mechanistic analysis reveals that the hybrid system fundamentally alters internal force distribution patterns， concentrating moments at strategically reinforced short piers while redistributing seismic energy through controlled sliding. Compared to fully-fixed systems， the hybrid configuration achieves a 30%-35% reduction of internal force concentration at critical pier locations while maintaining effective displacement control. This study establishes that the rational allocation of fixed bearings to shorter piers combined with sliding mechanisms at taller piers creates an optimal stiffness distribution for seismic energy dissipation. The validated numerical framework and proposed design methodology provide both theoretical foundations and practical guidelines for performance-based seismic design of spatially complex bridge systems. These findings offer essential insights for enhancing structural safety and reliability in earthquake-prone regions， potentially leading to the development of more resilient bridge designs in the future.
Active vibration reduction technology for mixed spectrum noise
ZHONG Zhi;NIU Guobiao;LIU Lei;SHAN Mingguang;[Objective] In engineering systems， vibration and noise arise from the coupling of mechanical energy across multiphysical fields. These phenomena are governed by complex excitation sources， nonlinear transmission paths， and system-specific modal characteristics. Consequently， purely narrowband (line-spectrum) or purely broadband (continuous-spectrum) vibration and noise signals are rare under operational conditions. Instead， structural resonances and other dynamic effects produce a mixed spectrum， characterized by narrowband line-spectrum components superimposed on a broadband continuous-spectrum background. This mixed-spectrum behavior necessitates advanced control strategies to effectively mitigate vibration and noise. Previous studies on active noise control technology mainly focused on the control of narrowband vibration and energy-eminent line spectrum noise with periodic characteristics， while they paid less attention to broadband vibration noise (with nonperiodic time-varying characteristics) that reduces the overall vibration damping effect. Vibration control for actual working conditions must break through the unimodal thinking of traditional algorithms and establish broadband and narrowband synergistic control algorithms so as to improve the overall vibration damping effect of the equipment. [Methods] Aiming at the actual vibration conditions close to the wideband and narrowband hybrid vibration model， a vibration reduction device based on the pretrained selection coefficient model of the mixed-spectrum hybrid vibration noise active control (MSN-HVNC) algorithm is designed and successfully used in the vibration abatement active control experiments. The hybrid control algorithm is used for vibration noise abatement. Moreover， the wideband noise control subsystem uses a pretrained neural network model to select filter coefficients for updating the coefficients of the filtered-x least mean square (FxLMS) algorithm and thereby controlling the wideband noise， while the narrowband noise control subsystem abates the line-spectrum noise， which is concentrated in energy. The overall damping level of the algorithm is measured in terms of the residual vibration noise to update the controller weights. [Results and Conclusions] The damping effect of the vibration-damping device based on the MSN-HVNC algorithm is 23.6 and 21.3 dB under single-frequency 50-Hz excitation in Case 1 and single-frequency 75-Hz excitation in Case 2， respectively， and the damping effect under mixed excitation vibration signals in multisource coupled vibration scenarios in Case 3 is 12.0 dB. The average damping effect of the MSN-HVNC algorithm is better than that of the FxLMS algorithm for both the single-frequency narrowband line-spectrum noise case and the complex vibration noise case. The MSN-HVNC algorithm is better than the FxLMS algorithm for both single-frequency narrowband linear spectrum noise and complex vibration noise conditions and exhibits a good damping effect for vibration noise. The vibration damping device accelerates the speed of noise control in the form of integrated control with the pretrained coefficient model and independent subsystems， which better meets the engineering needs of modern equipment intelligence and high efficiency， and provides an innovative solution for vibration and noise control in fields such as ship power systems.
Experimental study on low-frequency electrical characteristics of fracture-filling natural gas hydrate sediments
XING Lanchang;WANG Yunlong;WANG Yonghui;HAN Weifeng;WEI Wei;LIU Bao;[Objective] Field drilling observations have revealed that natural gas hydrates can be of several types， including the pore-filling type， the fracture-filling type， or a combination thereof， within geological formations. Electrical parameters are commonly used to estimate hydrate saturation and sediment permeability. However， findings for pore-filling hydrates cannot be directly applied to fracture-filling hydrates because of their distinct characteristics. Consequently， comprehensive investigations integrating experimental， numerical， and theoretical approaches are essential. This study provides an experimental platform for characterizing the low-frequency electrical properties of fracture-filling hydrate sediments， supporting the development of evaluation models for hydrate saturation and sediment permeability. [Methods] First， a three-dimensional finite-element numerical model is developed using COMSOL Multiphysics to simulate the electrical field and optimize electrode structural parameters. Second， a testing apparatus is designed based on the optimized electrodes and the four-electrode principle to measure the low-frequency electrical parameters of hydrate-bearing samples. A scheme for preparing sediment samples containing fracture-filling hydrates is also established， along with a method for processing test data. Third， the influence of hydrate saturation and fracture count on the low-frequency electrical properties of fracture-filling hydrate sediments is analyzed using the electrical double layer (EDL) polarization theory. [Results] The results reveal the following. First， for the spatial arrangement of the four electrodes， the minimum measurement error in conductivity is achieved when the radius of the disk-shaped potential electrode is equal to the inner radius of the ring-shaped current electrode. Second， for the analyzed electrical circuit， the relative errors of the real and imaginary parts of the electrical impedance are 8.7% and 5.9%， respectively. Third， within the low-frequency range from 1×10~(-2) to 1× 10~(3) Hz， as the saturation of the fracture-filling hydrates increases， the electrical conduction of the hydrate-bearing sediments decreases， and the EDL polarization strength decreases， leading to reductions in the real part and peak value of the imaginary part of complex conductivity. Finally， the tetrahydrofuran hydrates synthesized in the experiment exhibit a porous structure with interconnected pore water. Under identical hydrate saturation conditions， an increased number of fractures allows more water to seep into the hydrates from the sea sand， enhancing the sample’s electrical conduction while reducing the EDL polarization strength. Consequently， the real part of complex conductivity increases， and the peak value of the imaginary part decreases. [Conclusions] Finite-element modeling is an effective tool for optimizing electrode array designs for impedance measurements. The testing apparatus and experimental scheme developed in this study adequately meet the requirements for preparing fracture-filling hydrate samples and measuring their low-frequency complex conductivity. Given that hydrate saturation and fracture parameters influence complex conductivity， future experimental work focusing on fracture characteristics， such as shape， density， and dip angle， is warranted. Such research will contribute significantly to the development of evaluation models for hydrate saturation and sediment permeability applicable to fracture-filling hydrate reservoirs.
Sag measurement system of overhead transmission lines based on laser point cloud
LI Peng;JING Xiaochuan;NING Hao;MENG Qingwei;ZHU Mingxiao;[Objective] In recent years， with the rapid development of the economy， the demand for electricity and the scale of the global power grid have rapidly expanded. As an important channel for power transmission， the safe and stable operation of transmission lines is of vital importance. The sag of power conductors is a crucial parameter that can affect the working state of transmission lines. Therefore， achieving effective monitoring and adjustment of the sag of power conductors in transmission lines has become an important task in power line inspection. Effective monitoring of sag provides an important guarantee for the healthy operation of a transmission network. [Methods] This paper proposes an experimental platform for collecting the point cloud data of overhead transmission lines with an unmanned aerial vehicle (UAV) LiDAR as the main body. A software and hardware system applied to the sag measurement of power conductor point clouds is designed. A method for tracing the transmission conductors and completing the missing point clouds based on three-dimensional point clouds is proposed. By taking advantage of the high precision of laser point clouds， an accurate measurement of the conductor sag is realized. The specific process steps are as follows: 1) the UAV point cloud collection platform is used to collect the point cloud data of the overhead transmission line， and the point cloud data of the transmission line in the target section are obtained. 2) Kd-tree spatial reconstruction is carried out on the obtained point clouds of the overhead transmission line to accelerate the positioning speed of the target points and the searching speed of the neighboring points. 3) On this basis， conductor tracing is carried out on the reconstructed point clouds of the transmission line， and the target conductor is extracted from them. 4) The integrity of the collected point clouds of the power conductor is checked. If there are missing data， the cubic spline interpolation method is used to perform spatial shape fitting on the conductor point clouds. Then， according to the fitting results， data completion processing is carried out on the missing data part to obtain the complete conductor point clouds. 5) Finally， for the obtained complete conductor point cloud data， the sag of the target section of the conductor is calculated according to the sag calculation model and the final measurement result is obtained. [Results and Conclusions] This paper conducts measurement experiments on a typical section of the JL3/G1A-630/45 overhead transmission line of the Hanzhong–Zhengzhou line to verify the performance of the proposed sag measurement system. Verified by the measurement experiments， this measurement system can effectively and accurately measure the sag of power conductors and exhibits good robustness and high efficiency. It can accurately complete the task of measuring the conductor sag even when there are missing conductor data. In addition， this sag measurement system is a noncontact measurement， which has the advantages of convenience and safety. It provides a novel means for sag monitoring of high-voltage overhead transmission lines and can provide certain technical references for subsequent work， such as the inspection of the transmission network of the power system.
Experimental study on beam position monitor based on silicon pixel chip Topmetal
LIU Jun;GAO Chaosong;WANG Hulin;SUN Xiangming;[Objective] A beam monitor is an important component in a particle accelerator， enabling real-time measurement and characterization of beam parameters， such as position， intensity， spot size， and other information about the beam. These measurements are essential for optimizing the accelerator performance， ensuring beam stability， and conducting high-precision experiments. Traditional beam monitors often rely on scintillators， wire chambers， or semiconductor detectors， each with inherent limitations in resolution， noise， or radiation hardness. To address these challenges， this paper explores the use of Topmetal， a low-noise and high-resolution silicon pixel sensor fabricated using complementary metal–oxide–semiconductor (CMOS) technology， as the charge collection electrode in a gas-based beam monitor. [Methods] The proposed beam monitor integrates a Topmetal sensor into a gas detector structure， where ionizing particles generate electron–ion pairs in the gas chamber. The ionized electrons drift toward the Topmetal pixel array under the influence of an applied electric field and are sensed and read by Topmetal. The position of the beam particles was calculated based on the signal distribution on the pixel array. A dedicated readout electronics system was designed to process the signals from the beam monitor， which consists of front- and back-end electronics. The front-end electronics consists of a Topmetal bonding board and a motherboard. To increase the sensitive area of the detector， four Topmetal-II chips were installed in one row on the bonding board. The motherboard mainly implements four functions: power supply for the chips， bias voltage provision， control signal fan-out， and analog output buffering. The back-end electronics were designed based on a Xilinx Kintex-7 series field-programmable gate array， which was mainly responsible for Topmetal-II chip configuration， receiving analog output signals for analog-to-digital conversion， data packaging and caching， data transmission， and other functions. The readout electronics system was designed with low noise， fast signal digitization， and efficient data acquisition. To validate the feasibility and evaluate the performance of the beam monitor， tests using ~(241)Am α-particles and heavy ion beams were conducted in addition to the electronic tests. [Results] The tests proved that all the designed functions of the readout electronics system worked as expected. For the downlink， the readout electronics system can correctly configure the Topmetal chip， whereas for the uplink， it can read out the data of the chip and transmit the data to the computer through the ethernet. The ~(241)Am α particles test revealed that the whole detector system of the beam monitor， including the high-voltage system， gas system， and electronic system， worked as expected， and the detector could successfully register individual α particles. The beam tests demonstrated that the detector could work stably under the beam environment and resolve individual beam particles with the beam flux of 10~(4)–10~(6 )pps. With each pixel size of 83 μm×83 μm， the Topmetal-based beam monitor can achieve excellent position resolution， making it suitable for high-precision beam diagnostics. Furthermore， the detector's gas-based design offers flexibility in adjusting the sensitivity and dynamic range by varying the gas mixture and pressure. [Conclusions] This paper provides a new approach for high-position-resolution beam monitoring， combining the advantages of CMOS pixel sensors and gas detectors. The Topmetal-based system offers excellent spatial resolution compared with traditional beam monitors， along with low noise and radiation tolerance. Future work will focus on improving the rate capability of detectors for high-intensity beam applications and exploiting gas amplification mechanisms. The successful implementation of this technology could significantly enhance beam diagnostics in the accelerators， particularly in applications requiring micron-level precision， such as synchrotron light sources， medical proton and ion therapy， and particle and nuclear physics experiments.