TY - JOUR
T1 - A Simple Free-Fold Test to Measure Bending Stiffness of Slender Soft Actuators
AU - McDonald, Gillian J.
AU - Detournay, Emmanuel
AU - Kowalewski, Timothy M.
N1 - Publisher Copyright:
© 2016 IEEE.
PY - 2021/10/1
Y1 - 2021/10/1
N2 - A reliable estimate for bending stiffness is critical to many soft robot models when predicting everything from robot-environment contact to buckling resistance. Current methods for predicting actuator bending stiffness rely on highly accurate knowledge of material characteristics, which are not trivial to obtain for composite actuators. Additionally, current models for fluidic actuators often depend on a pressure-independent bending stiffness despite pressure playing a non-negligible role in bending stiffness behavior. Methods to measure actuator stiffness often require costly instrumentation to measure or perturb the motions and forces required to measure actual bending stiffness. We introduce a simple free-fold test to empirically estimate the bending stiffness of slender soft actuators - pressurized or unpressurized and composite or homogeneous - which requires the measurement of one distance from a single image of a specific robot pose. The resulting model also shows that the change in actuator weight per unit length can be used to determine the dependence of bending stiffness on actuation pressure.
AB - A reliable estimate for bending stiffness is critical to many soft robot models when predicting everything from robot-environment contact to buckling resistance. Current methods for predicting actuator bending stiffness rely on highly accurate knowledge of material characteristics, which are not trivial to obtain for composite actuators. Additionally, current models for fluidic actuators often depend on a pressure-independent bending stiffness despite pressure playing a non-negligible role in bending stiffness behavior. Methods to measure actuator stiffness often require costly instrumentation to measure or perturb the motions and forces required to measure actual bending stiffness. We introduce a simple free-fold test to empirically estimate the bending stiffness of slender soft actuators - pressurized or unpressurized and composite or homogeneous - which requires the measurement of one distance from a single image of a specific robot pose. The resulting model also shows that the change in actuator weight per unit length can be used to determine the dependence of bending stiffness on actuation pressure.
KW - Soft robot applications
KW - medical robots and systems
KW - soft robot materials and design
KW - soft sensors and actuators
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U2 - 10.1109/lra.2021.3114960
DO - 10.1109/lra.2021.3114960
M3 - Article
AN - SCOPUS:85115748956
SN - 2377-3766
VL - 6
SP - 8702
EP - 8709
JO - IEEE Robotics and Automation Letters
JF - IEEE Robotics and Automation Letters
IS - 4
ER -