The maneuverability and stealth of aerial-aquatic vehicles(AAVs)is of significant importance for future integrated air-sea combat missions.To improve the maneuverability and stealth of AAVs near the water surface,this...The maneuverability and stealth of aerial-aquatic vehicles(AAVs)is of significant importance for future integrated air-sea combat missions.To improve the maneuverability and stealth of AAVs near the water surface,this paper proposed a high-maneuverability skipping motion strategy for the tandem twin-rotor AAV,inspired by the motion behavior of the flying fish to avoid aquatic and aerial predators near the water surface.The novel tandem twin-rotor AAV was employed as the research subject and a strategybased ADRC control method for validation,comparing it with a strategy-based PID control method.The results indicate that both control methods enable the designed AAV to achieve high stealth and maneuverability near the water surface with robust control stability.The strategy-based ADRC control method exhibits a certain advantage in controlling height,pitch angle,and reducing impact force.This motion strategy will offer an inspiring approach for the practical application of AAVs to some extent.展开更多
Near-field ground motion amplification in sedimentary basins is widely observed and crucial to earthquake hazard assessment.However,the effects of basin topography coupled with the low-velocity layer(LVL)on ground mot...Near-field ground motion amplification in sedimentary basins is widely observed and crucial to earthquake hazard assessment.However,the effects of basin topography coupled with the low-velocity layer(LVL)on ground motion amplification are not fully understood.By constructing 3D basin models with surrounding mountain terrains and performing ground motion simulations,we compare the ground motion characteristics with different basin LVL depths and LVL velocities.The velocity contrast between the LVL and bedrock controls the amplification magnitude.The maximum amplification area in the model changes from the central part to the periphery part of the basin as the velocity contrast decreases and can be greatly influenced by the distance between the source and the basin.The amplification also spreads along the mountain edge circling the basin.Our work sheds light on the distribution of amplification within sedimentary basins surrounded by mountains,revealing that the velocity contrast between the LVL and bedrock plays a pivotal role in controlling the magnitude of amplification.展开更多
基金supported by Southern Marine Science and Guangdong Laboratory(Zhuhai)(Grant No.SML2023SP229)。
文摘The maneuverability and stealth of aerial-aquatic vehicles(AAVs)is of significant importance for future integrated air-sea combat missions.To improve the maneuverability and stealth of AAVs near the water surface,this paper proposed a high-maneuverability skipping motion strategy for the tandem twin-rotor AAV,inspired by the motion behavior of the flying fish to avoid aquatic and aerial predators near the water surface.The novel tandem twin-rotor AAV was employed as the research subject and a strategybased ADRC control method for validation,comparing it with a strategy-based PID control method.The results indicate that both control methods enable the designed AAV to achieve high stealth and maneuverability near the water surface with robust control stability.The strategy-based ADRC control method exhibits a certain advantage in controlling height,pitch angle,and reducing impact force.This motion strategy will offer an inspiring approach for the practical application of AAVs to some extent.
基金supported by the University of Science and Technology of China(USTC)Research Funds of the Double First-Class Initiative(YD2080002009)the National Natural Science Foundation of China(42074049 and 41974042)the Youth Innovation Promotion Association of the Chinese Academy of Sciences(2023471).
文摘Near-field ground motion amplification in sedimentary basins is widely observed and crucial to earthquake hazard assessment.However,the effects of basin topography coupled with the low-velocity layer(LVL)on ground motion amplification are not fully understood.By constructing 3D basin models with surrounding mountain terrains and performing ground motion simulations,we compare the ground motion characteristics with different basin LVL depths and LVL velocities.The velocity contrast between the LVL and bedrock controls the amplification magnitude.The maximum amplification area in the model changes from the central part to the periphery part of the basin as the velocity contrast decreases and can be greatly influenced by the distance between the source and the basin.The amplification also spreads along the mountain edge circling the basin.Our work sheds light on the distribution of amplification within sedimentary basins surrounded by mountains,revealing that the velocity contrast between the LVL and bedrock plays a pivotal role in controlling the magnitude of amplification.
