Snakes exhibit extraordinary ecological diversity and occupy a broad range of terrestrial,aquatic,and intermediate environments.Despite their widespread capacity for swimming,quantitative assessments of their aquatic ...Snakes exhibit extraordinary ecological diversity and occupy a broad range of terrestrial,aquatic,and intermediate environments.Despite their widespread capacity for swimming,quantitative assessments of their aquatic locomotion remain scarce.Furthermore,the roles of intraspecific variation in shaping swimming performance and kinematics have been largely overlooked,hindering robust interspecific comparisons.This study systematically investigated intraspecific and interspecific variation in 287individuals representing seven snake species along a terrestrial to aquatic continuum.Nine conventional swimming traits were quantified,including swimming speed and undulation characteristics such as frequency,wavelength,lateral velocities(head,body and tail) and amplitudes(head,body and tail).Undulation frequency and lateral velocity exhibited strong positive correlations with swimming speed,whereas wavelength showed a strong negative correlation.Semi-aquatic taxa attained the highest swimming speeds,while fully aquatic snakes displayed the lowest speeds.Intraspecific variation in swimming performance and kinematics was moderately reduced in aquatic species.Morphological traits,sex,and reproductive status significantly influenced both speed and kinematic profiles within species.Principal component analyses further revealed distinct kinematic domains among certain species(e.g.,no overlap between aspic viper and sea snakes),while others,such as the green whip snake,exhibited broad overlap with all taxa examined.These findings demonstrate that ecological specialization to aquatic habitats does not unilaterally dictate swimming speed or kinematic patterns.Moreover,conventional kinematic parameters alone are insufficient to study the evolutionary trajectories of aquatic locomotion in snakes.Integrating hydrodynamic,endurance capacity,and diving performance will be essential to better understand how natural selection has shaped locomotion in aquatic snakes.展开更多
An assessment of the human motion repeatability for three selected Activities of Daily Living(ADL)is performed in this paper.These exercises were prescribed by an occupational therapist for the upper limb rehabilitati...An assessment of the human motion repeatability for three selected Activities of Daily Living(ADL)is performed in this paper.These exercises were prescribed by an occupational therapist for the upper limb rehabilitation.The movement patterns of five participants,recorded using a Qualisys motion capture system,are compared based on the Analysis of Variance(ANOVA)method.This survey is motivated by the need to find the appropriate task workspace of a 6-degrees of freedom cable-driven parallel robot for upper limb rehabilitation,which is able to reproduce the three selected exercises.This comparison is performed to justify,whether or not,there is enough similarity between the participants’gestures,and so a single reference trajectory can be adopted as the robot-prescribed workspace.Using the results of the comparative study,an optimization process of the sought robot design is carried out,where the structure size and the cable tensions simultaneously minimized.展开更多
This paper presents a new design of CADEL,a cable-driven elbow-assisting device,with light weighting and control improvements.The new device design is appropriate to be more portable and user-oriented solution,present...This paper presents a new design of CADEL,a cable-driven elbow-assisting device,with light weighting and control improvements.The new device design is appropriate to be more portable and user-oriented solution,presenting additional facilities with respect to the original design.One of potential benefits of improved portability can be envisaged in the possibility of house and hospital usage keeping social distancing while allowing rehabilitation treatments even during a pandemic spread.Specific attention has been devoted to design main mechatronic components by developing specific kinematics models.The design process includes an implementation of specific control hardware and software.The kinematic model of the new design is formulated and features are evaluated through numerical simulations and experimental tests.An evaluation from original design highlights the proposed improvements mainly in terms of comfort,portability and user-oriented operation.展开更多
The vast diversity of morphologies,body size,and lifestyles of snakes represents an important source of information that can be used to derive bio-inspired robots through a biology-push and pull process.An understandi...The vast diversity of morphologies,body size,and lifestyles of snakes represents an important source of information that can be used to derive bio-inspired robots through a biology-push and pull process.An understanding of the detailed kinematics of swimming snakes is a fundamental prerequisite to conceive and design bio-inspired aquatic snake robots.However,only limited information is available on the kinematics of swimming snake.Fast and accurate methods are needed to fill this knowledge gap.In the present paper,three existing methods were compared to test their capacity to characterize the kinematics of swimming snakes.(1)Marker tracking(Deftac),(2)Markerless pose estimation(DeepLabCut),and(3)Motion capture were considered.(4)We also designed and tested an automatic video processing method.All methods provided different albeit complementary data sets;they also involved different technical issues in terms of experimental conditions,snake manipulation,or processing resources.Marker tracking provided accurate data that can be used to calibrate other methods.Motion capture posed technical difficulties but can provide limited 3D data.Markerless pose estimation required deep learning(thus time)but was efficient to extract the data under various experimental conditions.Finally,automatic video processing was particularly efficient to extract a wide range of data useful for both biology and robotics but required a specific experimental setting.展开更多
基金supported by the French Government through the National Research Agency (ANR)part of the ANR DRAGON-2 Project (ANR-20-CE02-0010)。
文摘Snakes exhibit extraordinary ecological diversity and occupy a broad range of terrestrial,aquatic,and intermediate environments.Despite their widespread capacity for swimming,quantitative assessments of their aquatic locomotion remain scarce.Furthermore,the roles of intraspecific variation in shaping swimming performance and kinematics have been largely overlooked,hindering robust interspecific comparisons.This study systematically investigated intraspecific and interspecific variation in 287individuals representing seven snake species along a terrestrial to aquatic continuum.Nine conventional swimming traits were quantified,including swimming speed and undulation characteristics such as frequency,wavelength,lateral velocities(head,body and tail) and amplitudes(head,body and tail).Undulation frequency and lateral velocity exhibited strong positive correlations with swimming speed,whereas wavelength showed a strong negative correlation.Semi-aquatic taxa attained the highest swimming speeds,while fully aquatic snakes displayed the lowest speeds.Intraspecific variation in swimming performance and kinematics was moderately reduced in aquatic species.Morphological traits,sex,and reproductive status significantly influenced both speed and kinematic profiles within species.Principal component analyses further revealed distinct kinematic domains among certain species(e.g.,no overlap between aspic viper and sea snakes),while others,such as the green whip snake,exhibited broad overlap with all taxa examined.These findings demonstrate that ecological specialization to aquatic habitats does not unilaterally dictate swimming speed or kinematic patterns.Moreover,conventional kinematic parameters alone are insufficient to study the evolutionary trajectories of aquatic locomotion in snakes.Integrating hydrodynamic,endurance capacity,and diving performance will be essential to better understand how natural selection has shaped locomotion in aquatic snakes.
基金supported by the"PHC Utiquc"program of the French Ministry of Foreign Affairs and Ministry of Higher Education,Research and Innovation and the Tunisian Ministry of Higher Education and Scientific Research.P.n°19G1121the support of the Erasmus+KA 107 program.
文摘An assessment of the human motion repeatability for three selected Activities of Daily Living(ADL)is performed in this paper.These exercises were prescribed by an occupational therapist for the upper limb rehabilitation.The movement patterns of five participants,recorded using a Qualisys motion capture system,are compared based on the Analysis of Variance(ANOVA)method.This survey is motivated by the need to find the appropriate task workspace of a 6-degrees of freedom cable-driven parallel robot for upper limb rehabilitation,which is able to reproduce the three selected exercises.This comparison is performed to justify,whether or not,there is enough similarity between the participants’gestures,and so a single reference trajectory can be adopted as the robot-prescribed workspace.Using the results of the comparative study,an optimization process of the sought robot design is carried out,where the structure size and the cable tensions simultaneously minimized.
文摘This paper presents a new design of CADEL,a cable-driven elbow-assisting device,with light weighting and control improvements.The new device design is appropriate to be more portable and user-oriented solution,presenting additional facilities with respect to the original design.One of potential benefits of improved portability can be envisaged in the possibility of house and hospital usage keeping social distancing while allowing rehabilitation treatments even during a pandemic spread.Specific attention has been devoted to design main mechatronic components by developing specific kinematics models.The design process includes an implementation of specific control hardware and software.The kinematic model of the new design is formulated and features are evaluated through numerical simulations and experimental tests.An evaluation from original design highlights the proposed improvements mainly in terms of comfort,portability and user-oriented operation.
基金Agence Nationale de la recherche(Grant no.ANR-20-CE02-0010).
文摘The vast diversity of morphologies,body size,and lifestyles of snakes represents an important source of information that can be used to derive bio-inspired robots through a biology-push and pull process.An understanding of the detailed kinematics of swimming snakes is a fundamental prerequisite to conceive and design bio-inspired aquatic snake robots.However,only limited information is available on the kinematics of swimming snake.Fast and accurate methods are needed to fill this knowledge gap.In the present paper,three existing methods were compared to test their capacity to characterize the kinematics of swimming snakes.(1)Marker tracking(Deftac),(2)Markerless pose estimation(DeepLabCut),and(3)Motion capture were considered.(4)We also designed and tested an automatic video processing method.All methods provided different albeit complementary data sets;they also involved different technical issues in terms of experimental conditions,snake manipulation,or processing resources.Marker tracking provided accurate data that can be used to calibrate other methods.Motion capture posed technical difficulties but can provide limited 3D data.Markerless pose estimation required deep learning(thus time)but was efficient to extract the data under various experimental conditions.Finally,automatic video processing was particularly efficient to extract a wide range of data useful for both biology and robotics but required a specific experimental setting.
