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
In this research,a comparative analysis was conducted on the performance and efficiency of the dual-anchor soft robot(DASR)and the extension-contraction soft robot(ECSR).These robots were constructed by imitating the ...In this research,a comparative analysis was conducted on the performance and efficiency of the dual-anchor soft robot(DASR)and the extension-contraction soft robot(ECSR).These robots were constructed by imitating the locomotion of razor clams.The penetration force for extension actuators and the anchorage force for expansion actuators in dry sand with distinct relative densities were tested by differentiating input air pressure and length-to-diameter ratios(λ).On the basis of the findings,a DASR and an ECSR were developed.DASR comprised two expansion actuators as the head and the tail segments at two ends,and one extension actuator as the middle segment.ECSR was composed of an extension actuator.A method based on the force equilibrium was introduced to ascertain and adjust the geometric parameters(length of each segment)of DASR.The burrowing-out performance and efficiency of DASR and ECSR in sands with distinct relative densities were explored.The results revealed that DASR exhibited high efficiency in dense sand in terms of lower time of burrowing-out,slip-to-advancement ratio,and cost of transport.ECSR might perform better in looser sand in terms of higher average burrowing-out velocity,higher advancement in each cycle,and lower energy consumption.However,it had larger slips than DASR.DASR could realize steady advancement and net displacement in each cycle and effectively decrease slips.These findings demonstrate the benefits and usability of the dual-anchor motion and offer new insights into the application of the dual-anchor mechanism in the burrowing of robots.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.
基金financially supported by the Natural Science Foundation of Jiangsu Province,China(No.BK 20221502)the National Natural Science Foundation of China(No.42477147)。
文摘In this research,a comparative analysis was conducted on the performance and efficiency of the dual-anchor soft robot(DASR)and the extension-contraction soft robot(ECSR).These robots were constructed by imitating the locomotion of razor clams.The penetration force for extension actuators and the anchorage force for expansion actuators in dry sand with distinct relative densities were tested by differentiating input air pressure and length-to-diameter ratios(λ).On the basis of the findings,a DASR and an ECSR were developed.DASR comprised two expansion actuators as the head and the tail segments at two ends,and one extension actuator as the middle segment.ECSR was composed of an extension actuator.A method based on the force equilibrium was introduced to ascertain and adjust the geometric parameters(length of each segment)of DASR.The burrowing-out performance and efficiency of DASR and ECSR in sands with distinct relative densities were explored.The results revealed that DASR exhibited high efficiency in dense sand in terms of lower time of burrowing-out,slip-to-advancement ratio,and cost of transport.ECSR might perform better in looser sand in terms of higher average burrowing-out velocity,higher advancement in each cycle,and lower energy consumption.However,it had larger slips than DASR.DASR could realize steady advancement and net displacement in each cycle and effectively decrease slips.These findings demonstrate the benefits and usability of the dual-anchor motion and offer new insights into the application of the dual-anchor mechanism in the burrowing of robots.
