• 中国科技核心期刊
  • JST收录期刊

2022 Vol. 30, No. 5

Display Method:
Research on Flexible Triboelectric Nanogenerator for Underwater Energy Harvesting
LIU Xiang-yu, WANG Yan, WANG Hao, XU Min-yi
2022, 30(5): 543-549. doi: 10.11993/j.issn.2096-3920.202112016
Abstract:
The marine distributed sensor network is composed of numerous wireless sensor nodes, which are crucial for ocean development and protection. These sensors are highly dependent on batteries and difficult to operate for long working times. Therefore, developing marine energy-harvesting devices is necessary for achieving in situ self-powered sensors. According to the principle of the triboelectric effect, this study proposed a flexible triboelectric nanogenerator(F-TENG) composed of flexible polymer films, which vibrates under waves and ocean currents and converts mechanical energy to electrical energy. This study established the working model of F-TENG and further explored its vibration mode and output performance. The results showed that the output performance of the F-TENG increased with the increasing amplitude, frequency, and flow rate within a certain range, and the parallel power increased with the increasing unit. This provides a new concept for realizing self-powered of marine distributed sensors.
State of Health Estimation of Li-ion Batteries Based on GWO-LSSVM
LI Ju-chen, HU Yu-li, GAO Jian, ZENG Li-teng, ZHENG Yi, DAI Wen-shuai
2022, 30(5): 550-557, 566. doi: 10.11993/j.issn.2096-3920.202109007
Abstract:
The algorithms currently applied to state of health(SOH) estimation require numerous data samples for training and the estimation effect is not good. To address this issue, this study proposed a least-squares support vector machine(LSSVM) algorithm based on the grey wolf optimization(GWO) algorithm to estimate the SOH using the grey relational analysis method to choose constant current charging time as the input characteristic. Considering the 18650 lithium cobalt oxide battery charge/discharge cycle test as an example, the established algorithm model was used to estimate the SOH of batteries with different capacity specifications under different proportions of training set samples. The estimated results were compared with those obtained by the LSSVM algorithm based on the grid search method and the LSSVM algorithm based on the particle swarm optimization algorithm. The experimental results showed that the LSSVM algorithm model based on the GWO algorithm is suitable for small-sample data and is characterized by small estimation errors; therefore, it is more effective for battery SOH.
A Concept of Nuclear Reactor Power for Unmanned Undersea Vehicle
GUO Jian, YU Rong-jun, AN Wei-jian, WANG Ao, LI Lai-dong, GAO Jian, LI Xiao-hui
2022, 30(5): 558-566. doi: 10.11993/j.issn.2096-3920.202201008
Abstract:
High-speed long-range unmanned undersea vehicles can expand various new combat modes. However, the power system is one of its bottlenecks. Nuclear power is an effective solution to address this problem. The miniaturization of the nuclear reactor power system is technically difficult. In this study, we simplified the system architecture, optimized the equipment layout scheme, and proposed a conceptual scheme of a nuclear reactor power system with an outer diameter of less than 533 mm, a length of no more than 3 m, a weight of no more than 750 kg, and the ability to output 100 kW of electric power based on the combination of a water-cooled thermal neutron reactor and thermoelectric power generation technology. Therefore, it is expected to enable the nuclear-powered unmanned undersea vehicle to be carried by a universal warship and launched from the 533 mm torpedo tube, increasing the mission flexibility. The cost of the nuclear power system can be significantly reduced and has the potential for mass production by adopting a reactor configuration with low fuel loading and using mature technology as much as possible. After estimating the key parameters of nuclear physics, thermal engineering, fluids, and mechanics, the feasibility of the scheme is preliminarily proved.
Thermodynamic Simulation Analysis of Variable Buoyancy Device for Underwater Gliders
ZHAO Hong-chang, HUANG Qiao-gao, LIU Jing
2022, 30(5): 567-574. doi: 10.11993/j.issn.2096-3920.202109015
Abstract:
The heat generated by its driving motor and pump affects the internal structure of the device when a variable-buoyancy device on an underwater glider is operating, thus posing risks to its normal operation. To address this problem, the finite element method was used to establish a thermodynamic simulation model of the variable-buoyancy device. The temperature field distribution of the piston of the device in the ideal uniform motion state at the points where it reaches thermal equilibrium at different water depths was simulated. Moreover, the temperature characteristics of the variable buoyancy device change with water depth were obtained. The results show that among the selected working conditions with different water depths, the temperature reached its lowest at a water depth of 500 m and was highest at the sea surface. At the sea surface and depth of 100 m, the highest temperatures of the device at thermal equilibrium were found on the right piston, which were 31.49 and 26.90°C respectively. Under other working conditions, the highest temperatures of the device at thermal equilibrium were found in the gland of the pump model. Furthermore, the temperature field distribution of the variable buoyancy device at the points when it reaches thermal equilibrium at a depth of 1 500 m at different motor speeds was simulated, and the temperature characteristics of the variable buoyancy device changing with motor speed were obtained. The results show that among the selected working conditions with different motor speeds, the temperature of the device at thermal equilibrium reached its highest, which is 40.95℃, when the motor speed was 5 000 r/min and was found on the gland of the pump model. The simulation results indicate the high-temperature locations of the device during operation, thereby providing an important reference for analyzing whether key parts of the variable buoyancy device cannot operate properly because of overheating.
3D Flow Field Characteristics and Hydrodynamic Optimization of Supercavitating Torpedoes Based on THINC/QQ Scheme
XIAO Teng, XIE Bin, DU Yan-ping
2022, 30(5): 575-585. doi: 10.11993/j.issn.2096-3920.202112002
Abstract:
The OPENFOAM platform was used to perform three-dimensional numerical simulations of the complex flow process of supercavitating torpedoes to investigate the morphological evolution of cavitation and hydrodynamic characteristics of supercavitating torpedoes. A numerical model of the volume of incompressible fluid was developed by integrating the THINC/QQ scheme, shear stress transport (SST) k-ω turbulence model and Schnerr-Sauer cavitation model, and the accuracy of the solver was comparatively verified by the results of the water tunnel experiments. Furthermore, the supercavitating behaviors were numerically investigated for a tailless torpedo considering crucial parameters including velocity, cavitator shape and surface wettability, and the three-dimensional flow field evolution process and hydrodynamic features of the supercavitating torpedo under typical operating conditions were obtained. In addition, the supercavitating flow field and hydrodynamic features of various cavitators with different shapes and sizes were compared. Results show that a cavitator with a certain taper or a low drag coefficient can effectively decrease the navigating drag. However, the reduced volume of the cavity may affect the stability of navigation. The effect of the hydrophobic material on the torpedo surface and its distribution on the hydrodynamic performance of the supercavitating torpedo was investigated as well. The results can provide some guidance for studies on drag reduction for supercavitating torpedoes.
Research on Unpowered Trim Ascent Motion Characteristics of Deep-sea Vehicles
ZHAO Zhi-chao, LI Tian-chen, GU Hai-tao, GAO Hao
2022, 30(5): 586-596. doi: 10.11993/j.issn.2096-3920.202111001
Abstract:
To improve the ascent response speed of unpowered deep-sea vehicles, and meet the requirements of mission loads for its water-exit attitude, considering the effect of ocean currents and buoyancy changes, a space motion simulation model of the vehicle was established. The quaternion method and the space motion equation of autonomous undersea vehicles were used to solve the singular problem of a large trim angle and vertical ascent motion. The effects of net buoyancy, distance between the center of gravity and buoyancy, rudder angle, initial launch conditions, and marine environmental disturbances on the trim ascent motion of the vehicle were explored and investigated. The results show that the space motion equation of a deep-sea vehicle based on the quaternion method can effectively avoid solving the singular problem of the attitude when the vehicle is ascending at a large trim angle or vertical attitude. Unpowered deep-sea vehicles can achieve a large vertical ascent speed and reduce the horizontal drift distance with a large trim angle or a vertical attitude. The disturbance of buoyancy changes and initial launch conditions have a great influence on the ascent state of the vehicle. The research provides references for the overall layout and the prediction of large trim angles and vertical ascents of deep-sea vehicles.
Research on Influence of Operating Depth on Motion State of Underwater Gliders
YE Xiao-wei, LIU Yan-min, ZHANG Wen-zhong, LIU Yi-fu, YAO Zhi-chong
2022, 30(5): 597-604. doi: 10.11993/j.issn.2096-3920.202104016
Abstract:
Net buoyancy, which drives underwater gliders, accounts for approximately 0.5% of their displacement, and its small change may significantly affect the state of their motion. During the gliding process, the displacement changes dynamically owing to the variation in seawater density and pressure with depth, thus resulting in a change in net buoyancy that would then affect the steady state of gliding. In this study, the effect of the change in net buoyancy on the steady state of the gliding motion was studied based on the dynamic equilibrium equation. By combining the mathematical and dynamical models of displacement change with depth the influence of depth on the gliding motion state was studied through simulations. The results show that: 1) the actual motion of underwater gliders under the influence of depth is dynamically balanced gliding, instead of steady balanced gliding; 2) the displacement-depth variation affects the gliding speed with a marginal effect on gliding attitude; 3) without additional control, gliding speed decreases first and then increases in the diving stage, and increases first and then decreases in the rising stage; and 4) the influence of the change in net buoyancy on gliding attitude could be eliminated by adjusting the position of the internal sliding mass, which requires little power. This study provides a reference for the precise control of underwater gliders used in marine environment monitoring and detection.
Underwater Image Enhancement Based on UNDERWATER-CUT Model
YAO Peng, LIU Yu-hui
2022, 30(5): 605-611. doi: 10.11993/j.issn.2096-3920.202111004
Abstract:
A weakly supervised underwater image enhancement algorithm based on the UNDERWATER-CUT model was proposed to address color distortion and contrast imbalance in underwater images. The algorithm network was trained without paired training sets, and the contrast learning positive and negative samples were constructed by image chunking, which constrains the image generation content. The structural similarity(SSIM) loss function was used to constrain the image enhancement to ensure that the structure of the objects remains unchanged during the transformation of the CUT model from the underwater image domain to the dewatered image domain. A linear combination of two simple functions was used to approximate the InfoNCE loss of the CUT model, converging the improved model training to the optimal value easily. The experimental results demonstrate that color distortion is significantly corrected in the enhanced image using this algorithm, and the object structure in the restored image is the same as that in the original image.
Research on Underwater Echo Generation Method Based on Small Sample
WANG Chen-yu, LIU Li-wen, LIU Gang, LI Bo, YANG Yun-chuan
2022, 30(5): 612-620. doi: 10.11993/j.issn.2096-3920.202108015
Abstract:
Under the tide led by artificial intelligence, the application of deep learning methods in underwater target recognition has gained increasing attention. However, obtaining underwater sample data from actual scientific research is extremely difficult because of environmental constraints, time, cost, and other factors. An insufficient number of samples leads to poor training effects in deep learning models. Generative adversarial networks(GAN), a new artificial intelligence technology, have a wide range of applications in data enhancement, image generation, and other fields. However, the traditional GAN model is unsuitable for underwater echo samples and cannot be used directly for sample data generation. Therefore, this study proposed an underwater echo signal generation method based on an improved GAN for a small sample to address the problem of insufficient underwater target data. Combining the characteristics of the echo signal, the study designed and built a convolution unit-based GAN model. Furthermore, an echo signal generation simulation experiment was carried out using the pool experimental test data. Finally, the effectiveness of the generated signal was verified at the level of the signal waveform and amplitude probability distribution. The experimental results show that the improved GAN model proposed in this study is suitable for generating highly realistic original echo signals in the case of small samples, which provides a new idea for the active detection and recognition of underwater targets.
Task Assignment Method for Multiple UUVs Based on Multi-population Genetic Algorithm
FAN Xue-man, XUE Chang-you, ZHANG Hui
2022, 30(5): 621-630. doi: 10.11993/j.issn.2096-3920.202107001
Abstract:
The quality of task assignment schemes for multiple unmanned undersea vehicles(UUVs) during cooperative reconnaissance is key to the operational effectiveness or even the success of missions. A multi-population genetic algorithm based on man-machine fusion was proposed for task allocation of multi-base, multi-target, and multi-constraint cooperative reconnaissance to solve the problems of premature convergence and low efficiency of traditional genetic algorithms. The algorithm can better balance global optimization and local search and break through the performance bottleneck of the classical genetic algorithm, which relies only on a single population for optimization, by introducing multiple populations to search the solution space cooperatively. In addition, human prior knowledge was used as heuristic information to assist population initialization in improving the convergence efficiency of the algorithm, and a forgetting strategy was introduced to alleviate possible incomplete evolution. The results of the simulation based on typical scenarios show that the proposed multi-population genetic algorithm is robust, has high optimization efficiency, and can generate high-quality collaborative task allocation schemes..
Simulation Calculation of Mode Shape Slope for Rocket-assisting Torpedo
WANG Sheng, BAI Zhi-ning, GUO Jun
2022, 30(5): 631-635. doi: 10.11993/j.issn.2096-3920.202112006
Abstract:
The slenderness ratio of a rocket-assisting torpedo is relatively large, and its connecting structure is complex and multiform. This study proposed a dynamic simulation modeling method for a rocket-assisting torpedo. The detailed modeling of the connecting structure was simplified, including the wedge ring, thrust block, and clamp. The modal of the rocket-assisting torpedo was calculated and the mode vector was extracted. The mode shape slope of the inertial measurement component installation position was calculated too. This study provided an analysis method to design input parameters for the attitude control and the determination of the installation position of the inertial installation component.
Intelligent Measurement System Design for Mechanical Properties of Sediments in All-sea-depth
CHI Shu-kai, HAN Tao, GE Xian-Wei
2022, 30(5): 636-643, 649. doi: 10.11993/j.issn.2096-3920.202112021
Abstract:
Ocean research and development has entered the era of all-sea-depth technology. A sediment mechanical property survey system with all-sea depth capability is very important in seabed resource exploration and research. This study used the in-situ test system of sediment mechanical properties as the object of study and designed an intelligent measurement system for all-sea-depth static touch exploration test, cross-board shear test, full-flow penetration test, and in-situ sampling function, which combines the characteristics of difficult communication, multiple uncertainties, small range of changes in shear strength of deep-sea sediments, and the influence of sea pressure on mechanical properties, according to the specifications and conventions of deep-sea sediment soil mechanical tests. The implementation of the system relies on the ARM+FPGA structure on the hardware and the state machine design mode of the software and satisfies the requirements of the all-sea-depth test on responsiveness and fault tolerance. A series of sample soils and sea experiments have demonstrated that the system can work at all-sea depths and accurately test the mechanical properties of sediments.
Modular Design of Lithium-ion Battery Packs for Cylindrical Battery Cabins of AUV
SONG De-yong, HE Wei-wei, LI Bang-peng, ZHENG Peng, YANG Shen-shen, WANG Lei
2022, 30(5): 644-649. doi: 10.11993/j.issn.2096-3920.202112009
Abstract:
For autonomous undersea vehicles(AUV), the capacity and reliability of battery packs depend on their range, safety, and overall performance. According to the technical specifications of the energy system of an AUV, the 21700 lithium-ion battery was selected as the unit cell for the battery pack design with the idea of a modular and double-redundant design. A single module can completely use the inner space of the cylindrical battery cabin to improve the capacity of the battery packs, while the structure of multiple modules in series and parallel is convenient for locating faults and carrying out maintenance. Two parallel battery packs can result improved reliability. The test results show that the energy density of the system can reach to 200 Wh/kg and battery packs in modular design have higher energy density, reliability, and maintainability.
Design of a Buoy Winch for Manned Submersibles
YAO Chen-jiao, LUO Sheng
2022, 30(5): 650-655. doi: 10.11993/j.issn.2096-3920.202112007
Abstract:
To address the positioning and communication requirements of cable relay buoys connected to manned submersibles working in deep sea for a long time, a technical scheme of an underwater buoy retracting and releasing winch suitable for manned submersibles is proposed in this study. The scheme is based on the working characteristics of winches on manned submersibles that work in underwater environments and are intelligently controlled in manned cabins. We discussed the working principles, structural composition, hydraulic control system of the winch, and calculation of the main parameters. The results show that the scheme can satisfy the demand for retracting and releasing the buoys of manned submersibles, thereby providing a reference for the design of this type of winch.
Analytical Method for Hitting Probability of Supercavity Torpedoes
XIE Chao, ZHOU Jing-jun, WAN Ya-min, SONG Shu-long, WANG Meng-hao
2022, 30(5): 656-664. doi: 10.11993/j.issn.2096-3920.202111002
Abstract:
Formulating an analytical model for the hitting probability of supercavity torpedoes is an effective approach to clarify the influence of errors in the attack process. This study establishes a distribution model of the torpedo miss distance during the straight attack of supercavity torpedoes by considering the influence of platform detection and torpedo navigation errors. Simultaneously, considering the influence of the target waterline on the hitting probability, the hitting range model of a target is established, and based on theoretical analysis, this paper proposes unifying the target navigation and platform detection errors, which can ensure the calculation accuracy and effectively avoid modeling difficulties caused by the two-dimensional distribution of the target location. Based on this, an analytical model for the hitting probability of a supercavity torpedo is established, and the computational accuracy of the analytical model is verified by comparing it with a statistical method. A sensitivity analysis is conducted, and the results clarify that the errors with the greatest impact on the hitting probability are the detection errors of the initial line of a sight angle and the torpedo course errors, providing a reference for improving the operational effectiveness of supercavity torpedoes.
Method of Storage Life Assessment of Intercept Missile Based on Whole Life Cycle
MA Hao-wen, XIONG Yong, WU Luan-chun
2022, 30(5): 665-670. doi: 10.11993/j.issn.2096-3920.202202009
Abstract:
The storage life of intercept missiles was evaluated based on the whole life cycle theory to address the challenges in assessing the storage life of interceptor under the existing conditions. Based on the intercept missile life and storage life profile, the storage life of the intercept missile can be evaluated by analyzing the intercept missile life design using the life data of similar products and the storage life test of accelerated aging of newly developed components. Combined with the technical preparation and testing of the intercept missile, the main components and materials affecting the storage life of the product intercept missile were analyzed. Life assessment analysis and life tests were carried out on the main components and materials that affect the storage life. We used relevant tests, similar products, or existing data and conclusions to evaluate the life of intercept missiles comprehensively. The results show that the storage life of the intercept missile satisfies these requirements.
Designing an Effective Evaluation System for Attacking UUVs
ZOU Qi-ming, SONG Shu-long, PENG Yuan-ming, WANG Meng-hao, ZHOU Jing-jun
2022, 30(5): 671-676. doi: 10.11993/j.issn.2096-3920.202109019
Abstract:
This study proposed the design of an effective evaluation system for attacking unmanned undersea vehicles(UUVs) to solve problems related to operational applications, project argumentation, development, testing, and training. Furthermore, an integrated confrontation simulation platform and a componentized underwater acoustic physical field-effect model were developed to construct different offensive and defensive scenarios and experimental design schemes. The system can simulate offensive and defensive confrontations and evaluate the effectiveness of attacking long-range precise strikes of UUVs. The reliability of this effective evaluation was obtained by verifying the simulation model of underwater offensive and defensive confrontations using an evaluation case. The system provides a reference for this evaluation and assistive decision making for attacking UUVs.
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