The development and utilization of marine resources by human beings is gradually moving towards the deep sea,and deep-sea aquaculture platforms have emerged to meet the needs of aquaculture and food security.To better...The development and utilization of marine resources by human beings is gradually moving towards the deep sea,and deep-sea aquaculture platforms have emerged to meet the needs of aquaculture and food security.To better understand the motion response characteristics of the main structure of the full-submersible deep-sea aquaculture platform under the action of water waves,Fluent software is used to numerically simulate regular waves,irregular waves,and strong nonlinear waves,and their effects on the six degrees of freedom motion response of the main structure of the full-submersible deep-sea aquaculture platform are analyzed.The study found that under the towing condition,the smaller the wave direction angle,the more intense the movement.Under the platform’s working conditions,the larger the wave direction angle,the more intense the movement.展开更多
A new path planning method for mobile robots in globally unknown environment with moving obstacles is pre- sented. With an autoregressive (AR) model to predict the future positions of moving obstacles, and the predict...A new path planning method for mobile robots in globally unknown environment with moving obstacles is pre- sented. With an autoregressive (AR) model to predict the future positions of moving obstacles, and the predicted position taken as the next position of moving obstacles, a motion path in dynamic uncertain environment is planned by means of an on-line real-time path planning technique based on polar coordinates in which the desirable direction angle is taken into consideration as an optimization index. The effectiveness, feasibility, high stability, perfect performance of obstacle avoidance, real-time and optimization capability are demonstrated by simulation examples.展开更多
According to the actual requirements,profile and rolling energy consumption are selected as objective functions of rolling schedule optimization for tandem cold rolling.Because of mechanical wear,roll diameter has som...According to the actual requirements,profile and rolling energy consumption are selected as objective functions of rolling schedule optimization for tandem cold rolling.Because of mechanical wear,roll diameter has some uncertainty during the rolling process,ignoring which will cause poor robustness of rolling schedule.In order to solve this problem,a robust multi-objective optimization model of rolling schedule for tandem cold rolling was established.A differential evolution algorithm based on the evolutionary direction was proposed.The algorithm calculated the horizontal angle of the vector,which was used to choose mutation vector.The chosen vector contained converging direction and it changed the random mutation operation in differential evolution algorithm.Efficiency of the proposed algorithm was verified by two benchmarks.Meanwhile,in order to ensure that delivery thicknesses have descending order like actual rolling schedule during evolution,a modified Latin Hypercube Sampling process was proposed.Finally,the proposed algorithm was applied to the model above.Results showed that profile was improved and rolling energy consumption was reduced compared with the actual rolling schedule.Meanwhile,robustness of solutions was ensured.展开更多
A method to determine the direction angle for bionic navigation is proposed. In order to do it, observation models of polarized light were obtained through full-sky imaging polarimetry, and the symmetry line （ solar ...A method to determine the direction angle for bionic navigation is proposed. In order to do it, observation models of polarized light were obtained through full-sky imaging polarimetry, and the symmetry line （ solar meridian） was detected firstly; then the angle between solar meridian and the system moving direction was derived from simultaneous model, and the relative position of the sun was calculated by astronomical knowledge ; finally, the direction angle for bionic navigation was evaluated by utilizing sun azimuth to revise the angle between solar meridian and the system moving direction. This study improves previous conception with the changing solar meridian as a reference direction （0°） and provides a theoretic foundation for polarized light to be applied into navigation.展开更多
To enhance the navigation efficiency of inland new-energy ships and reduce energy consumption and emissions,this study investigates wind load coefficients under 13 conditions,combining a wind speed of 2.0 m/s with win...To enhance the navigation efficiency of inland new-energy ships and reduce energy consumption and emissions,this study investigates wind load coefficients under 13 conditions,combining a wind speed of 2.0 m/s with wind direction angles ranging from 0°to 180°in 15°increments.Using Computational Fluid Dynamics(CFD)simulations,the wind load is decomposed into along-course(Cx)and transverse(Cy)components,and their variation with wind direction is systematically analyzed.Results show that Cx is maximal under headwind(0°),decreases approximately following a cosine trend,and reaches its most negative value under tailwind(180°).Cy peaks at crosswind(90°)and exhibits an overall sinusoidal distribution.Certain wind directions produce a compound effect on the hull,particularly when the crosswind angle approaches 90°.Flow analysis reveals that wind generates a high-pressure zone on the windward side and a low-pressure vortex region on the leeward side,inducing unstable forces and increasing energy consumption.Based on the wind pressure distribution,a targeted structural optimization is proposed to mitigate high-pressure resistance.These findings provide a theoretical basis for hull form optimization and energy-efficient ship design.展开更多
Sliding-mode triboelectric nanogenerator(S-TENG)is based on the coupling of triboelectrification and electrostatic induction,converting electrical energy from sliding motion.Introducing micro-textures into the sliding...Sliding-mode triboelectric nanogenerator(S-TENG)is based on the coupling of triboelectrification and electrostatic induction,converting electrical energy from sliding motion.Introducing micro-textures into the sliding surface,and adjusting the angle between the texture and sliding direction(direction angle)may achieve performance anisotropy,which provides novel ideas for optimizing the tribology and electrification performance of S-TENG.To guide the performance optimization based on the anisotropy,in this paper,groove micro-textures were fabricated on the surface of S-TENG,and anisotropic tribology and electrification performance were obtained through changing the direction angle.Based on the surface analysis and after-cleaning tests,the mechanism of the anisotropy was explained.It is shown that the anisotropy of friction coefficient can be attributed to the changes of texture edge induced resistance and groove captured wear debris,while the voltage anisotropy is due to the variations of debris accumulated on the sliding interface and the resulting charge neutralization.Among the selected 0°–90°direction angles,S-TENG at angle of 90°exhibits relatively small stable friction coefficient and high open-circuit voltage,and thus it is recommended for the performance optimization.The open-circuit voltage is not directly associated with the friction coefficient,but closely related to the wear debris accumulated on the sliding interface.This study presents a simple and convenient method to optimize the performance of S-TENG,and help understand the correlation between its tribology and electrical performance.展开更多
基金supported by the Selfcultivation Project of Collaborative Innovation Center of Marine Equipment and Technology Institute of Jiangsu University of Science and Technology (No.XTCX202402)。
文摘The development and utilization of marine resources by human beings is gradually moving towards the deep sea,and deep-sea aquaculture platforms have emerged to meet the needs of aquaculture and food security.To better understand the motion response characteristics of the main structure of the full-submersible deep-sea aquaculture platform under the action of water waves,Fluent software is used to numerically simulate regular waves,irregular waves,and strong nonlinear waves,and their effects on the six degrees of freedom motion response of the main structure of the full-submersible deep-sea aquaculture platform are analyzed.The study found that under the towing condition,the smaller the wave direction angle,the more intense the movement.Under the platform’s working conditions,the larger the wave direction angle,the more intense the movement.
文摘A new path planning method for mobile robots in globally unknown environment with moving obstacles is pre- sented. With an autoregressive (AR) model to predict the future positions of moving obstacles, and the predicted position taken as the next position of moving obstacles, a motion path in dynamic uncertain environment is planned by means of an on-line real-time path planning technique based on polar coordinates in which the desirable direction angle is taken into consideration as an optimization index. The effectiveness, feasibility, high stability, perfect performance of obstacle avoidance, real-time and optimization capability are demonstrated by simulation examples.
基金funded by the Science and Technology Research Project of Education Department of Liaoning(L2015387)Natural Science Foundation of Liaoning(201602542)the National Natural Science Foundation of China(51407119)
文摘According to the actual requirements,profile and rolling energy consumption are selected as objective functions of rolling schedule optimization for tandem cold rolling.Because of mechanical wear,roll diameter has some uncertainty during the rolling process,ignoring which will cause poor robustness of rolling schedule.In order to solve this problem,a robust multi-objective optimization model of rolling schedule for tandem cold rolling was established.A differential evolution algorithm based on the evolutionary direction was proposed.The algorithm calculated the horizontal angle of the vector,which was used to choose mutation vector.The chosen vector contained converging direction and it changed the random mutation operation in differential evolution algorithm.Efficiency of the proposed algorithm was verified by two benchmarks.Meanwhile,in order to ensure that delivery thicknesses have descending order like actual rolling schedule during evolution,a modified Latin Hypercube Sampling process was proposed.Finally,the proposed algorithm was applied to the model above.Results showed that profile was improved and rolling energy consumption was reduced compared with the actual rolling schedule.Meanwhile,robustness of solutions was ensured.
基金Sponsored by Natural Science Foundation of Beijing(1093016)
文摘A method to determine the direction angle for bionic navigation is proposed. In order to do it, observation models of polarized light were obtained through full-sky imaging polarimetry, and the symmetry line （ solar meridian） was detected firstly; then the angle between solar meridian and the system moving direction was derived from simultaneous model, and the relative position of the sun was calculated by astronomical knowledge ; finally, the direction angle for bionic navigation was evaluated by utilizing sun azimuth to revise the angle between solar meridian and the system moving direction. This study improves previous conception with the changing solar meridian as a reference direction （0°） and provides a theoretic foundation for polarized light to be applied into navigation.
基金Shandong Province Key R&D Program(Innovation Capacity Improvement Project for Science,Technology Small,Medium-Sized Enterprises)Project No.:2025TSGCCZZB0679Project ZR2024QE394 supported by Shandong Provincial Natural Science Foundation.
文摘To enhance the navigation efficiency of inland new-energy ships and reduce energy consumption and emissions,this study investigates wind load coefficients under 13 conditions,combining a wind speed of 2.0 m/s with wind direction angles ranging from 0°to 180°in 15°increments.Using Computational Fluid Dynamics(CFD)simulations,the wind load is decomposed into along-course(Cx)and transverse(Cy)components,and their variation with wind direction is systematically analyzed.Results show that Cx is maximal under headwind(0°),decreases approximately following a cosine trend,and reaches its most negative value under tailwind(180°).Cy peaks at crosswind(90°)and exhibits an overall sinusoidal distribution.Certain wind directions produce a compound effect on the hull,particularly when the crosswind angle approaches 90°.Flow analysis reveals that wind generates a high-pressure zone on the windward side and a low-pressure vortex region on the leeward side,inducing unstable forces and increasing energy consumption.Based on the wind pressure distribution,a targeted structural optimization is proposed to mitigate high-pressure resistance.These findings provide a theoretical basis for hull form optimization and energy-efficient ship design.
基金supported by Beijing Natural Science Foundation(No.3224065)Guangdong Basic and Applied Basic Research Foundation(No.2021A1515110351)National Natural Science Foundation of China(No.51975042).
文摘Sliding-mode triboelectric nanogenerator(S-TENG)is based on the coupling of triboelectrification and electrostatic induction,converting electrical energy from sliding motion.Introducing micro-textures into the sliding surface,and adjusting the angle between the texture and sliding direction(direction angle)may achieve performance anisotropy,which provides novel ideas for optimizing the tribology and electrification performance of S-TENG.To guide the performance optimization based on the anisotropy,in this paper,groove micro-textures were fabricated on the surface of S-TENG,and anisotropic tribology and electrification performance were obtained through changing the direction angle.Based on the surface analysis and after-cleaning tests,the mechanism of the anisotropy was explained.It is shown that the anisotropy of friction coefficient can be attributed to the changes of texture edge induced resistance and groove captured wear debris,while the voltage anisotropy is due to the variations of debris accumulated on the sliding interface and the resulting charge neutralization.Among the selected 0°–90°direction angles,S-TENG at angle of 90°exhibits relatively small stable friction coefficient and high open-circuit voltage,and thus it is recommended for the performance optimization.The open-circuit voltage is not directly associated with the friction coefficient,but closely related to the wear debris accumulated on the sliding interface.This study presents a simple and convenient method to optimize the performance of S-TENG,and help understand the correlation between its tribology and electrical performance.
