TY - GEN
T1 - A strength based approach for the synthesis of a compliant nonlinear spring for an orthotic knee brace
AU - Krishnan, Girish
AU - Rank, Ryan
AU - Rokosz, John
AU - Carvey, Phil
AU - Kota, Sridhar
PY - 2013
Y1 - 2013
N2 - Lightweight mechanical energy-storage devices or springs with nonlinear strain-energy absorption rate are important building blocks for passive/quasi-passive rehabilitation robotics. They provide support and controllable energy storage/release into the system thereby making daily activities such as walking/running metabolically efficient for the disabled. These devices have stringent footprint constraints and must withstand 10 million cycles of loading for successful implementation on an orthotic device. Currently, there are no off-the-shelf springs or a systematic synthesis methodology that can meet these requirements in a deterministic fashion. In this paper, we demonstrate how existing body of knowledge in compliant mechanisms can be systematically leveraged to design spring geometries with distributed compliance that meet fatigue criteria and weight requirements. Towards this, we implement a strength-based approach to determine feasible initial solutions that upon optimization yield geometries with maximally distributed stresses. Such a framework is general and can be adapted for designing any compliant mechanism.
AB - Lightweight mechanical energy-storage devices or springs with nonlinear strain-energy absorption rate are important building blocks for passive/quasi-passive rehabilitation robotics. They provide support and controllable energy storage/release into the system thereby making daily activities such as walking/running metabolically efficient for the disabled. These devices have stringent footprint constraints and must withstand 10 million cycles of loading for successful implementation on an orthotic device. Currently, there are no off-the-shelf springs or a systematic synthesis methodology that can meet these requirements in a deterministic fashion. In this paper, we demonstrate how existing body of knowledge in compliant mechanisms can be systematically leveraged to design spring geometries with distributed compliance that meet fatigue criteria and weight requirements. Towards this, we implement a strength-based approach to determine feasible initial solutions that upon optimization yield geometries with maximally distributed stresses. Such a framework is general and can be adapted for designing any compliant mechanism.
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U2 - 10.1115/DETC2013-12727
DO - 10.1115/DETC2013-12727
M3 - Conference contribution
AN - SCOPUS:84896925532
SN - 9780791855935
T3 - Proceedings of the ASME Design Engineering Technical Conference
BT - 37th Mechanisms and Robotics Conference
PB - American Society of Mechanical Engineers
T2 - ASME 2013 International Design Engineering Technical Conferences and Computers and Information in Engineering Conference, IDETC/CIE 2013
Y2 - 4 August 2013 through 7 August 2013
ER -