Abstract
Modern passive ankle-foot prostheses do not exhibit appropriate biomechanics during walking, and are unable to adjust their mechanics for other mobility tasks, such as stair traversal or quiet standing. In this paper, we introduce a quasi-passive ankle-foot prosthesis that addresses these challenges; the ankle has a customizable, nonlinear torque-angle curve, and the overall stiffness can be varied continuously between mobility tasks. The variation in mechanics is accomplished by integrating two mechanisms: a cam-based transmission, in which rotation of the ankle joint causes deflection of a leaf spring, and an active sliding support beneath the leaf spring, which can modify the spring's effective stiffness. In addition to introducing the design, we present the mathematics to calculate the cam profile for any arbitrary torque-angle curve, and experimentally characterize the system for a desired curve based on human walking. Lastly, we demonstrate the full range of stiffness levels available and stiffness transition time.
Original language | English (US) |
---|---|
Title of host publication | ICRA 2017 - IEEE International Conference on Robotics and Automation |
Publisher | Institute of Electrical and Electronics Engineers Inc. |
Pages | 6672-6678 |
Number of pages | 7 |
ISBN (Electronic) | 9781509046331 |
DOIs | |
State | Published - Jul 21 2017 |
Event | 2017 IEEE International Conference on Robotics and Automation, ICRA 2017 - Singapore, Singapore Duration: May 29 2017 → Jun 3 2017 |
Publication series
Name | Proceedings - IEEE International Conference on Robotics and Automation |
---|---|
ISSN (Print) | 1050-4729 |
Other
Other | 2017 IEEE International Conference on Robotics and Automation, ICRA 2017 |
---|---|
Country/Territory | Singapore |
City | Singapore |
Period | 5/29/17 → 6/3/17 |
Funding
ACKNOWLEDGMENT The authors would like to thank Gordon Composites for donating the fiberglass spring. This work made use of the Central Laboratory for Materials Mechanical Properties supported by the MRSEC program of the National Science Foundation (DMR-1121262) at the Northwestern University Materials Research Science and Engineering Center.
ASJC Scopus subject areas
- Software
- Artificial Intelligence
- Electrical and Electronic Engineering
- Control and Systems Engineering