水下无人系统学报

A Verification Method of Formation Control of USV Cluster Based on Virtual-Real Integration

LIANG Xiao, YANG Chengbin, ZHANG Zhihao, LIU Dianyong, LI Wei, YU Changdong

2025, 33(4): 573-580. doi: 10.11993/j.issn.2096-3920.2025-0050

[Abstract](87) [FullText HTML] (20) [PDF 1623KB](31)

Abstract:
In the research field of unmanned surface vessel(USV) technology, the verification and optimization of autonomous algorithms are crucial for advancing this technology and have important research significance for improving system reliability, environmental adaptability, and mission execution efficiency. With the rapid development of digital twin technology, validation methods based on virtual-real integration have become key technical approaches in intelligent control algorithm research. In this context, this paper proposed a verification method for formation control of a USV cluster based on virtual-real integration. First, the concept of a five-dimensional virtual-real integration model for a USV cluster was introduced, providing a theoretical basis for experimental validation. Second, a physical USV experimental platform was constructed to enable autonomous navigation and control in real maritime environments. Third, a virtual test environment was developed using Unity3D software to model the maritime environment and USV models, and real-time communication with physical nodes was established. Finally, an unmanned autonomous control algorithm was designed to achieve formation control of the USV cluster. Experimental results show that the proposed method can effectively validate autonomous algorithms for USV clusters, providing new perspectives and paradigms for intelligent cooperative operations and simulation-based confrontation training of future maritime unmanned systems.

System Effectiveness Evaluation of Acoustic Glider Based on Optimized ADC Model

TANG Shuai, FAN Peiqin, ZHANG Chi, ZOU Jiayun

2025, 33(4): 581-588. doi: 10.11993/j.issn.2096-3920.2024-0175

[Abstract](24) [FullText HTML] (15) [PDF 717KB](3)

Abstract:
With the development of unmanned underwater technology, acoustic gliders are increasingly becoming advantageous platforms for marine environment observation and underwater target detection. Evaluating their system effectiveness has thus become a key focus. Based on the characteristics and influencing factors of the mission process, an effectiveness evaluation index system for acoustic glider systems was constructed. The traditional availability-dependability-capability(ADC) model was optimized by considering the effects of the marine environment and comprehensive support on acoustic gliders. The analytic hierarchy process(AHP) was used to determine the weights of the three-level indices. The feasibility of the model was verified by numerical examples, showing that the optimized ADC model produced more realistic evaluation results and provided a methodological reference for the effectiveness evaluation of unmanned maritime equipment.

Optimization Design and Simulation of Acoustic Adaptation Structure for Underwater Gliders

CHEN Bowen, ZHANG Lin, SUN Qindong, YU Fajun

2025, 33(4): 589-598. doi: 10.11993/j.issn.2096-3920.2025-0042

[Abstract](35) [FullText HTML] (17) [PDF 4412KB](12)

Abstract:
To address the technical bottleneck in balancing hydrodynamic efficiency and acoustic detection performance during the design of acoustic adaptation structures for long-endurance underwater gliders(UGs), this study proposed a dual-objective collaborative design method integrating computational fluid dynamics-finite element method(CFD-FEM) co-simulation. By coupling simulation of turbulent flow in arbitrary regions-computational continuum mechanics+(STAR-CCM+) for viscous flow analysis and COMSOL Multiphysics for acoustic-structure interaction, a parametric geometric model was proposed based on the Myring equation, utilizing the sharpness factor and aspect ratio as key variables. Multi-objective collaborative optimization was carried out by adopting intelligent optimization algorithms. The results indicate that the optimized acoustic adaptation structure achieves a total drag reduction of 10.4%–15.6% across a speed range of 0.5–3 m/s. Specifically, the configuration with an aspect ratio of 1.875 and a sharpness factor n = 2 exhibits a resistance reduction to 8.178 N at 1 m/s. Regarding acoustic performance, under 2 000 Hz plane wave incidence, the scattered sound pressure level increases by 1.5 dB; sidelobe suppression capability is enhanced by 2–3 dB, and acoustic reception directivity is improved significantly. Validation through angle of attack tests demonstrates that the optimized solution maintains drag reductions of 6%-17% within a ±10° angle of attack, effectively resolving the conflicting requirements between hydrodynamic resistance and acoustic performance inherent in traditional designs. The constructed “fluid-structure-acoustics” multiphysics collaborative optimization paradigm provides theoretical support for the engineering design of next-generation long-endurance, high-detection, and composite UGs and expands the UG multidisciplinary optimization methodology system.

Style Transfer-Based Augmentation for Side-Scan Sonar Images

BAI Zhongyu, XU Hongli, RU Jingyu, QIU Shaoxiong

2025, 33(4): 599-605. doi: 10.11993/j.issn.2096-3920.2025-0045

[Abstract](42) [FullText HTML] (7) [PDF 2530KB](8)

Abstract:
Side-scan sonar(SSS) has been extensively adopted in ocean exploration because of its stability and efficiency when deployed on autonomous undersea vehicles(AUVs). Nevertheless, the difficulty in acquiring SSS images and the limited availability of training samples severely constrain the performance of the deep neural network(DNN)-based SSS image classification. To mitigate this limitation, this paper proposed a multi-scale attention network(MSANet) that utilized optical-acoustic image pairs for data augmentation to enhance the generalization capacity of SSS image classification models. First, shallow and deep features were extracted from multiple encoder layers to comprehensively capture both content and style information. Next, a multi-scale attention module(MSAM) was introduced to extract both local and global contextual information of style features along the channel dimension. These style features were then effectively fused with optical features to achieve precise spatial alignment of optical and acoustic features. Finally, the fused multi-scale features were aligned and input to a decoder to generate high-fidelity SSS images that were subsequently used to train the classification network. Extensive experiments on real-world SSS datasets demonstrate that the proposed style transfer-based augmentation strategy can effectively generate high-quality simulated SSS image samples, thereby improving the performance of SSS image classification based on DNN.

Research on Weak Magnetic Control of IPMSM with Single Current Regulator Based on Improved Terminal Sliding Mode

GAN Shaowei, ZHOU Guoqiang, YU Zilei, SUN Jian, JIA Yuxin

2025, 33(4): 606-612. doi: 10.11993/j.issn.2096-3920.2024-0166

[Abstract](23) [FullText HTML] (10) [PDF 1092KB](3)

Abstract:
In view of the poor stability of permanent magnet motors in undersea vehicle propulsion systems under deep weak magnetic conditions, a weak magnetic control method with a single current regulator was proposed for the interior permanent magnet synchronous motor(IPMSM) based on integral terminal sliding mode control(ITSMC) of improved double power convergence rate. This method was based on the current limit circle and voltage limit circle. Below the base speed of the IPMSM, it adopted the maximum torque per ampere(MTPA) control. Above the base speed, it employed the single current regulator-variable Q-axis voltage(SCR-VQV) strategy for weak magnetic control. To enhance the system’s robustness, an ITSMC of improved double power convergence rate was proposed to replace the traditional proportional-integral control above the base speed under the SCR-VQV control. Finally, through experiments, the stable deep weak magnetic control capability of this weak magnetic control system was proved.

Adaptive Observation Method for CTD Data Based on Dolphin Deep-Sea Profiling Buoy

LIU Chu, HOU Fei, YANG Zerong, ZHOU Lingxiao, ZHU Xinke

2025, 33(4): 613-622. doi: 10.11993/j.issn.2096-3920.2025-0025

[Abstract](49) [FullText HTML] (15) [PDF 1923KB](7)

Abstract:
During the profiling observation process of deep-sea profiling buoys, an appropriate sensor sampling frequency must be implemented to reduce power consumption in data acquisition and transmission due to low-power design requirements. Based on the independently developed Dolphin deep-sea profiling buoy, this study established an optimized model for temperature and salinity data collection strategy using an adaptive genetic algorithm through simulation analysis combining peripheral device power consumption specifications and conductivity, temperature, and depth(CTD) profile data from the Argo program. Leveraging the strong correlation characteristics between adjacent profile data, the proposed method planned new-round sampling schemes by analyzing historical profile data features, while adaptively adjusting sampling frequency according to data variation trends during acquisition. The simulation analysis based on real-world data demonstrates that the profile data acquired through this observation method exhibits minimal deviation from actual measurements, while significantly reducing the overall power consumption of the profiling buoy compared to the pre-programmed deep-layer observation scheme.

Analysis of Multi-Degree-of-Freedom Equipment Shock Response Based on Deep Learning

HUANG Qinyi, ZHU Wei, MA Feng, CHEN Si, WANG Shuang

2025, 33(4): 623-629. doi: 10.11993/j.issn.2096-3920.2024-0143

[Abstract](111) [FullText HTML] (129) [PDF 1809KB](22)

Abstract:
To analyze the response of multi-degree-of-freedom ship equipment under explosive shock loads, this study proposed a deep learning-based shock response prediction model. Traditional single-degree-of-freedom models struggle to efficiently analyze the complex shock responses of multi-degree-of-freedom systems. By leveraging deep learning technology, especially the data feature extraction and nonlinear modeling capabilities of neural networks, this model learned the correlation between shock spectra and input shock loads from numerical simulation data, enabling efficient and accurate calculation of shock response spectra at critical points in ship structures. This approach overcame the limitations of existing models in handling multi-degree-of-freedom equipment and met the demand for rapid and precise analysis of complex system shock responses. Experimental results show that the model can accurately predict the shock response spectra of multi-degree-of-freedom equipment, with a relative error of less than 8% compared to simulation data, effectively resolving the bottlenecks of traditional models in multi-degree-of-freedom system analysis.

Analysis of the Effect of Structural Flexibility on Dynamic Characteristics of Power Tri-branching Reducers

YAN Hai, WEN Lihua, CAO Hao, SONG Wen

2025, 33(4): 630-637. doi: 10.11993/j.issn.2096-3920.2025-0041

[Abstract](33) [FullText HTML] (10) [PDF 1708KB](3)

Abstract:
To investigate the effect of structural flexibility of the housing, shaft, and spline coupling on the meshing stiffness of the gear and dynamic response of the powertrain system and compare the differences between different modeling methods, a power tri-branching reducer was taken as the object, and a fully flexible coupled dynamics model was established, as well as dynamic models considering different components as rigid. The influence of structural flexibility on meshing stiffness of the gear and dynamic response of the powertrain system was studied using time domain and frequency domain analysis. The results show that the effect of structural flexibility on meshing stiffness of the gear can be ignored; the flexibility of the housing has a significant impact on the vibration characteristics of the system, especially when the housing mode coincides or approaches the mesh frequency; the resonance makes the vibration response amplitude of the system significantly increase; ignoring the flexibility of the shaft may result in the loss of spectral lines at certain mesh frequencies; the flexibility of a spline coupling only affects the vibration characteristics of its connecting shaft and has a small impact on the vibration responses of other components of the system. Therefore, different analysis models need to be used for different analysis purposes. When analyzing meshing stiffness, only a rigid body model needs to be established. When analyzing the vibration characteristics of the system, it is necessary to use a fully flexible model.

Vector Propulsion AUV Path Planning Method Based on Deep Reinforcement Learning

PANG Zhouqi, LIN Xiaobo, HAO Chengpeng, CHENG Wenxin

2025, 33(4): 638-647. doi: 10.11993/j.issn.2096-3920.2025-0005

[Abstract](45) [FullText HTML] (8) [PDF 1689KB](14)

Abstract:
This study proposed a joint control method of “rudder + vector thruster” and utilized deep reinforcement learning technology to allocate the usage ratio of rudder and vector nozzle, enabling autonomous undersea vehicles(AUVs) to achieve enhanced path planning capabilities. This method balanced the high energy efficiency of rudder control and the high maneuverability of vector nozzle control, allowing the AUV to reach the target point with lower energy consumption. On the one hand, the study established a dynamic model of vector propulsion AUVs and verified that vector thrusters improved the maneuverability of AUVs but simultaneously reduced the AUV’s energy efficiency. On the other hand, the study employed an improved proximal policy optimization(IPPO) algorithm to solve the path planning problem under joint control mode. Firstly, considering the bounded nature of the action space for the problem, this method modeled the policy distribution using a Beta distribution and increased the penalty for vector nozzle control in the reward function based on the characteristics of the vector thruster. Secondly, the study improved the parameter update strategy of (proximal policy optimization)PPO and introduced a “rollback mechanism” to enhance the convergence efficiency of the algorithm. The simulation results verified that the proposed algorithm completed path planning tasks in complex environments under joint control, and it outperformed the unimproved algorithm in terms of convergence speed and path optimality.

Path Tracking Optimization for Unmanned Hydrofoil Vehicle Based on ILOS and IPID-GWO

BI Cheng, DUAN Fuhai

2025, 33(4): 648-656. doi: 10.11993/j.issn.2096-3920.2024-0177

[Abstract](22) [FullText HTML] (4) [PDF 1691KB](6)

Abstract:
In order to solve the path tracking problem of a new type of unmanned hydrofoil vehicle, a tracking strategy based on line of sight(LOS) guidance combined with an incremental proportional-integral-differential(IPID) controller was proposed. Firstly, the 3-DOF kinematic and dynamic models of the vehicle were established, and the control input was decoupled through the control strategy. The LOS guidance method was improved by combining the variable foresight distance and integral term, and the ILOS algorithm was obtained. The IPID controller used the desired heading angle obtained by the ILOS algorithm to dynamically control the tracking process. The compensation input when switching the tracking point was added to the algorithm to avoid the system’s out-of-control problem caused by excessive changes. The weight coefficients in the IPID controller were optimized and compared using the grey wolf optimizer(GWO) algorithm and genetic algorithm(GA). In Matlab, the ILOS and IPID controllers were used to track the given straight and curved mixed path in the absence and presence of interference. The tracking effect and lateral error were analyzed, and the feasibility and advancement of the combination of ILOS and IPID-GWO algorithms were verified.

Study on Full-Size Drop Impact Response Characteristics and Safety of Marine Equipment

WANG Tingting, SHEN Yongfu, MA Junli, JIAO Gangling, ZHANG Jian, WANG Yawei

2025, 33(4): 657-663. doi: 10.11993/j.issn.2096-3920.2025-0002

[Abstract](25) [FullText HTML] (10) [PDF 2517KB](8)

Abstract:
The drop safety of marine equipment is of paramount importance in daily operational tasks. To assess the safety of a full-size drop of a certain type of equipment, a finite element simulation model of the overall structure was established using LS-DYNA software. The numerical simulation and analysis of the horizontal drop from a height of 5 meters were conducted to obtain the impact response characteristics of the energetic material and each compartment. The results show that under 5-meter drop conditions, after multiple rebounds, plastic deformation occurs within the materials of each compartment. The maximum stress of the energetic material is located at the corresponding position in the cavity at the collision point between the structure and the ground. When the local pressure inside the energetic material exceeds its yield strength, deformation occurs. Although no ignition reaction happens during the entire collision process, the internal stress, temperature, and reactivity values of the energetic material show slight fluctuations, and minor local chemical reactions occur. A verification test of the 5-meter horizontal drop using a full-size structure is conducted. The experimental results are consistent with the simulation results, confirming that the structure does not ignite or explode. This study can be applied to the safety analysis and assessment of full-size drops for other marine equipment and can effectively guide the safety design and engineering development of such systems.

Influence of JWL State Equation Parameters on Numerical Simulation of Underwater Explosion Shock Waves of TNT Explosives

LI Hao, ZHANG Yuzhu, HU Haoran, ZHANG Xuan, WANG Jin, LUO Yi

2025, 33(4): 664-675. doi: 10.11993/j.issn.2096-3920.2025-0023

[Abstract](44) [FullText HTML] (16) [PDF 1533KB](7)

Abstract:
The state equation for detonation products is one of the fundamental equations in computational explosion mechanics, and changes in the values of its parameters directly affect the results of numerical analysis. This study focused on the influence of the parameters of the JWL(Jones-Wilkins-Lee) state equation for TNT explosives on the numerical simulation of underwater explosion shock waves. Based on the LS-DYNA finite element program, a refined one-dimensional numerical model of underwater explosion was constructed by comparing with empirical formulas. An in-depth analysis was conducted on the variation laws of key processes, such as the pressure attenuation of explosion shock waves and energy release under different values of each parameter in the JWL state equation for detonation products. The results show that the parameters of the JWL state equation have significant impacts on parameters such as the peak pressure, specific impulse, and specific shock wave energy of underwater explosion shock waves, and the impact varies at different distances from the explosion center. In terms of peak pressure, in the near field range, the influence of R₁ is much greater than that of other parameters, while in the middle and far field ranges, E₀ has the greatest influence. Moreover, a higher peak pressure indicates a faster attenuation. In terms of specific impulse, changes in E₀ have the greatest influence, and when E₀ is changed, the calculated value of specific impulse has a linear relationship with the parameter value. Similarly, E₀ has the greatest influence on specific shock wave energy. The research results can provide a reference basis for the reasonable selection of JWL equation parameters in the numerical simulation of underwater explosions.

Ship Radiated Noise Line Spectrum Enhancement Based on Adaptive Filtering-Deep Learning Fusion

CAI Tingting, YU Sunze, ZHAO Mei

2025, 33(4): 676-685. doi: 10.11993/j.issn.2096-3920.2025-0040

[Abstract](54) [FullText HTML] (23) [PDF 2018KB](16)

Abstract:
To address the challenge of identifying line spectrum features of ship radiated noise in complex underwater acoustic environments, a line spectrum enhancement model combining adaptive filtering and deep learning(DL) was proposed. This model integrated a double-layer collaborative adaptive filtering module with a DL module to form a multi-level feature enhancement framework. The adaptive filtering module combined frequency-domain adaptive filtering(FDAF) with the maximum correntropy criterion(MCC) to enhance the suppression of non-stationary noise while effectively reducing broadband background noise. The DL module employed a bi-directional long short-term memory(BiLSTM) network to extract the local temporal dependencies of line spectra. It also incorporated an attention residual mechanism to focus on weak line spectra and utilized a Transformer encoder to capture long-range correlations in the time-frequency domain. The model effectively combined the advantages of filtering and DL, both suppressing noise and enhancing the detection of weak line spectra. Simulation results demonstrate that the proposed method outperforms single adaptive filtering or DL models in terms of overall line spectrum enhancement and weak line spectrum enhancement. The effectiveness of this method is further validated through lake test data.

Short-Time Motion Analysis of Underwater High-Speed Moving Target Based on Pseudo-Linear Kalman Filter

ZHAO Junhao, MA Hui, WANG Mingzhou, ZHANG Jun, CAO Hao

2025, 33(4): 686-690, 698. doi: 10.11993/j.issn.2096-3920.2024-0171

[Abstract](43) [FullText HTML] (25) [PDF 1987KB](11)

Abstract:
Detection of underwater high-speed moving targets faces challenges, such as long active detection cycles, discontinuous data, and passive detection failing to obtain target range, which makes it difficult to quickly and effectively calculate target motion parameters. To address these issues, a short-term motion analysis method for underwater high-speed moving targets based on a pseudo-linear Kalman filter(PLKF) was proposed. This method employed only one initial active detection at the beginning and was primarily a passive target motion analysis(TMA) method within the horizontal plane, supplemented minimally by active detection. Mathematical models were established, and iterative equations were provided. Based on the prior assumption that the target maintains constant-velocity motion for the majority of the observation time, simulation analysis was conducted under constant-velocity motion conditions. The root mean square error of the predicted trajectory was calculated using the Monte-Carlo method. Simulation results demonstrate that compared to bearing-only TMA using purely passive detection, this method enabled rapid convergence of the target motion parameter solution within a short time, with convergence achieved within no more than 10 seconds.

Test Method for Complex Surface-Underwater Conditions of Deep-Sea Special Pressure Structure

CHEN Shagu, GAO Yuan, WU Zhirui, WANG Kun, ZHOU Cheng

2025, 33(4): 691-698. doi: 10.11993/j.issn.2096-3920.2024-0153

[Abstract](106) [FullText HTML] (49) [PDF 2869KB](14)

Abstract:
The separable head cover is a special pressure structure used in deep-sea unmanned systems that must balance long-term underwater pressure resistance with rapid separation when on the water surface. In order to study the overall performance of a deep-sea special pressure structure under complex surface-underwater conditions, a full-scale structural model of the separable head cover was developed for pressure and separation testing. Firstly, in response to the testing requirements for long-term seawater pressure environments during underwater operation, this study, based on the existing Chinese deep-sea environment simulation systems, proposed a test method that simulated coupled deep seawater-pressure conditions using a cabin device with skin balloons. Furthermore, in response to the testing requirements for rapid separation of the separable head cover after surfacing(in air), a safe and reliable inclined flange connection structure model rapid separation testing system was established. The test results of the full-scale model of the separable head cover show that the proposed testing method for complex surface–underwater conditions of a special pressure structure is reasonable and feasible. It can not only be used for pressure and separation testing of the separable head cover but also provide reference for the design and testing of similar pressure structures in other deep-sea equipment.

Research on Drag Reduction Optimization of Foldable Solar Wings for UUVs

WANG Chenyu, PENG Likun, CHEN Jiabao, CHEN Jia, WANG Huarui, PAN Wei

2025, 33(4): 699-706, 712. doi: 10.11993/j.issn.2096-3920.2024-0168

[Abstract](46) [FullText HTML] (14) [PDF 3502KB](9)

Abstract:
To respond to the endurance bottleneck faced by unmanned undersea vehicles(UUVs) in missions such as ocean observation and resource exploration, this paper studied the hydrodynamic performance optimization of a novel foldable solar wing. To balance computational efficiency and optimization accuracy, a parametric model of the wing was established in CAESES software with variables including wing point coordinates, rounding factors of wing edges, wing gaps, and gaps between the wing and the hull. Innovatively, a hybrid optimization framework combining Sobol global sampling and the non-dominatedsorting genetic algorithm II(NSGA-II) optimization algorithm was constructed. Firstly, the Sobol algorithm was used to generate 80 sample points within the threshold space of each variable to fully explore the design space, followed by multi-generation optimization through NSGA-II. To avoid the accuracy degradation of traditional surrogate models, a coupled computational process integrating high-precision hydrodynamic solutions and optimization algorithms was established, enabling automatic co-simulation between CAESES and STAR-CCM + software. Hydrodynamic analyses were conducted on UUVs equipped with wings of different shapes to explore the impact of different parameter combinations on total drag. The optimization results indicate that a certain height difference between the two wing sections protruding from the hull is beneficial for reducing total drag. Flow field analysis shows that the optimized shape effectively suppresses energy dissipation caused by turbulence. The proposed technical route of parametric modeling, intelligent optimization, and high-precision verification not only reduces the straight-line drag of the UUV with a new configuration but also provides a methodological reference for the optimization of complex appendages, possessing significant engineering value for improving the energy utilization efficiency of underwater equipment.

Evaluation of Information Usefulness in Human-Computer Interaction Based on Information Template Libraries

CHEN Weichang, XIAO Gang, DU Linlin, MA Jingjing, WU Tao

2025, 33(4): 707-712. doi: 10.11993/j.issn.2096-3920.2025-0022

[Abstract](37) [FullText HTML] (12) [PDF 1545KB](4)

Abstract:
In response to the problem of incomplete coverage of interactive content in traditional human-computer interaction degree evaluation of unmanned systems, based on the analysis of the characteristics of information transmission in different sentence structures, the concept of information usefulness was proposed and included in the indicator system of human-computer interaction degree evaluation. On this basis, the core elements of interactive content were used as information templates to construct a hierarchically classified library of information templates and design a method for calculating information usefulness by comparing it with the libraries. Quantitative assessment of the value of interactive content was conducted. Case studies verify the rationality of the construction of the information template library and the effectiveness of the information usefulness calculation method, which can provide reference and insights for the evaluation of human-computer interaction degree.

Application of State Estimation Algorithm for Autonomous Underwater Docking of UUVs

CHEN Weixin, LIU Tao, ZHANG Tao, LIU Feng

2025, 33(4): 713-721. doi: 10.11993/j.issn.2096-3920.2024-0161

[Abstract](63) [FullText HTML] (20) [PDF 1444KB](15)

Abstract:
Underwater autonomous dynamic docking of unmanned undersea vehicle(UUV) is one of the key technologies for their long-range cooperative operations. In view of the insufficient estimation accuracy of the motion state of the docking device during underwater dynamic docking of UUVs, an interacting multiple model adaptive unscented Kalman filter(IMM-AUKF) algorithm was proposed to estimate the motion state. By considering the large measurement error of the motion state of the docking device obtained by the UUVs’ own sensor, the UUV nonlinear observation model was established, and the adaptive unscented Kalman filter(AUKF) algorithm was used to update the observation noise in real time and reduce observation errors. To accurately describe the relative motion between UUVs and the docking device with a single motion model, the relative motion model set of UUVs and the docking device was established, and the IMM was used to describe the motion state and improve the filtering accuracy. Based on UUV docking test data, the estimation results of the motion state of the docking device by the UKF, AUKF, and IMM-AUKF algorithms were compared. The results show that the accuracy and stability of the IMM-AUKF algorithm are better than the other two algorithms. It can meet the requirements of underwater dynamic docking and improve the success rate of UUV docking.

Sensorless Speed Control of Induction Motors Using Reduced-Order Flux Linkage Observers with Strong Robustness to Stator Resistance

DUAN Luobao, WANG Jing, PAN Yang

2025, 33(4): 722-732. doi: 10.11993/j.issn.2096-3920.2025-0038

[Abstract](38) [FullText HTML] (12) [PDF 2180KB](12)

Abstract:
Sensorless speed control technology for induction motors has become an important technical approach in fields including modern industrial automation, robot control, and electric vehicle drives, due to its advantages of reduced system cost and volume, optimized hardware structure, high reliability, and ease of maintenance. However, this technology still faces critical challenges in the low-speed generating region. Specifically, the system may experience instability during low-speed operation, and the control performance is susceptible to variations in stator resistance. In response to these issues, this paper proposed an optimized gain design for the reduced-order flux linkage observer. This method ensured stable operation in low-speed generating regions and strong robustness against stator resistance variations without introducing additional stator resistance adaptation or online identification processes. In order to thoroughly verify the effectiveness and general applicability of the proposed method, load experiments were conducted across the entire low-speed range under different motor power levels and stator resistance error conditions. The experimental results demonstrate that the optimized reduced-order flux linkage observer exhibits excellent stability and robustness to stator resistance in the entire low-speed region, significantly enhancing system control performance.

Low-Power Long-Distance Wireless Communication Technologies for Marine Buoys: A Review

WANG Xiaobo, HU Xujuan, JI Xuefeng

2025, 33(4): 733-742. doi: 10.11993/j.issn.2096-3920.2025-0019

[Abstract](97) [FullText HTML] (19) [PDF 1495KB](31)

Abstract:
With the advancement of global ocean development and utilization, marine buoys, as key ocean observation devices, play a critical role in marine environment monitoring, weather forecasting, and ocean resource development. However, marine buoys are typically deployed far from land, facing numerous challenges such as long-distance data transmission and equipment power consumption limitations. Traditional satellite communication technologies provide reliable communication for offshore buoys, while the development of 5G technology offers new opportunities for nearshore buoys. With the rapid advancement of the Internet of Things(IoT) technology, modern low-power wide-area network(LPWAN) technologies have gradually become important options for wireless communication in marine buoys. Meanwhile, emerging low Earth orbit(LEO) technologies provide global communication support for marine buoys, particularly excelling in ultra-long-distance and deep-sea environments. This paper reviewed current low-power wireless communication technologies applicable to marine buoys, focusing on the application prospects and technical challenges of LPWAN, 5G, and LEO satellite communication. It also proposed future development directions, aiming to provide valuable references for advancing marine buoy communication systems.

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2025, Volume 33, Issue 4

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Current Issue 2025, Volume 33, Issue 4

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Current Issue
2025, Volume 33, Issue 4