This study focuses on the development and testing of a bio-inspired self-burrowing dual anchor soft probe for potential geotechnical applications.Dual anchor refers to the form of movement in soils in which some bival...This study focuses on the development and testing of a bio-inspired self-burrowing dual anchor soft probe for potential geotechnical applications.Dual anchor refers to the form of movement in soils in which some bivalve molluscs adopted by alternately generating anchoring effects in the soil through shell expansion and fluid-filled feet.By mimicking this mechanism,this study used pneumatic artificial muscles as soft actuators and developed an autonomous burrowing probe.The structure and the performance of the actuators and the probe were investigated and optimized.The burrowing-out process of the dual anchor probe was not a simple upward movement.Instead,it rose in the inflation phase and slipped downward in the deflation phase.The difference between the two was a stride in one single step.In the sands with relative densities of 30%,50%,and 80%,the total slips accounted for 18.8%,19.6%,and 26.9%of the total upward movements,respectively.Thus,the entire movement process showed a reciprocating upward trend.The burrowing process could be divided into a restricted stage and a free stage according to whether shear failure occurs in the overlying soil layer.When the soil density was high,the initial stage of burrowing was in a restricted stage.The amount of rise and slip were at a low level and increased slowly as the number of cycles increased.When the burrowing process was in the free stage,the increase was basically stable at a high value and accompanied by small slips.展开更多
Soft condensed-state physics is a disciplinary frontier of 20th-century physics. An interdiscipline in nature, it involves biology, chemistry and even pure mathematics. Taking the liquid crystal (LC) biomembrane as an...Soft condensed-state physics is a disciplinary frontier of 20th-century physics. An interdiscipline in nature, it involves biology, chemistry and even pure mathematics. Taking the liquid crystal (LC) biomembrane as an example, this article expounds the current development trend of this new and promising branch of contemporary physics.展开更多
借助庞特里亚金最大值原理(Pontryagin′s Maximal Principle,PMP),将月球燃耗最优软着陆问题转化为终端时间自由型两点边值问题(Two Point Boundary Value Problem,TPBVP)。采用一种基于初值猜测技术的线性摄动法求解TPBVP,得到最优软...借助庞特里亚金最大值原理(Pontryagin′s Maximal Principle,PMP),将月球燃耗最优软着陆问题转化为终端时间自由型两点边值问题(Two Point Boundary Value Problem,TPBVP)。采用一种基于初值猜测技术的线性摄动法求解TPBVP,得到最优软着陆轨迹。仿真结果表明,初值猜测技术得出的伴随变量初值均落在线性摄动法的收敛区间内,收敛速度快,优化精度高。最后研究了不同制动推力大小对软着陆性能的影响,结论为:增大制动发动机推力,既可缩短软着陆的时间,又能减少软着陆的燃料消耗。展开更多
基金supported by the Natural Science Foundation of Jiangsu Province,China(Grant No.BK20221502).
文摘This study focuses on the development and testing of a bio-inspired self-burrowing dual anchor soft probe for potential geotechnical applications.Dual anchor refers to the form of movement in soils in which some bivalve molluscs adopted by alternately generating anchoring effects in the soil through shell expansion and fluid-filled feet.By mimicking this mechanism,this study used pneumatic artificial muscles as soft actuators and developed an autonomous burrowing probe.The structure and the performance of the actuators and the probe were investigated and optimized.The burrowing-out process of the dual anchor probe was not a simple upward movement.Instead,it rose in the inflation phase and slipped downward in the deflation phase.The difference between the two was a stride in one single step.In the sands with relative densities of 30%,50%,and 80%,the total slips accounted for 18.8%,19.6%,and 26.9%of the total upward movements,respectively.Thus,the entire movement process showed a reciprocating upward trend.The burrowing process could be divided into a restricted stage and a free stage according to whether shear failure occurs in the overlying soil layer.When the soil density was high,the initial stage of burrowing was in a restricted stage.The amount of rise and slip were at a low level and increased slowly as the number of cycles increased.When the burrowing process was in the free stage,the increase was basically stable at a high value and accompanied by small slips.
文摘Soft condensed-state physics is a disciplinary frontier of 20th-century physics. An interdiscipline in nature, it involves biology, chemistry and even pure mathematics. Taking the liquid crystal (LC) biomembrane as an example, this article expounds the current development trend of this new and promising branch of contemporary physics.
文摘借助庞特里亚金最大值原理(Pontryagin′s Maximal Principle,PMP),将月球燃耗最优软着陆问题转化为终端时间自由型两点边值问题(Two Point Boundary Value Problem,TPBVP)。采用一种基于初值猜测技术的线性摄动法求解TPBVP,得到最优软着陆轨迹。仿真结果表明,初值猜测技术得出的伴随变量初值均落在线性摄动法的收敛区间内,收敛速度快,优化精度高。最后研究了不同制动推力大小对软着陆性能的影响,结论为:增大制动发动机推力,既可缩短软着陆的时间,又能减少软着陆的燃料消耗。
