Latch-based control of energy output in spring actuated systems
Abstract
The inherent force–velocity trade-off of muscles and motors can be overcome by instead loading and releasing energy in springs to power extreme movements. A key component of this paradigm is the latch that mediates the release of spring energy to power the motion. Latches have traditionally been considered as switches; they maintain spring compression in one state and allow the spring to release energy without constraint in the other. Using a mathematical model of a simplified contact latch, we reproduce this instantaneous release behaviour and also demonstrate that changing latch parameters (latch release velocity and radius) can reduce and delay the energy released by the spring. We identify a critical threshold between instantaneous and delayed release that depends on the latch, spring, and mass of the system. Systems with stiff springs and small mass can attain a wide range of output performance, including instantaneous behaviour, by changing latch release velocity. We validate this model in both a physical experiment as well as with data from the Dracula ant,Mystrium camillae, and propose that latch release velocity can be used in both engineering and biological systems to control energy output.
Document Details
- Document Type
- Pub Defense Publication
- Publication Date
- Jul 01, 2020
- Source ID
- 10.1098/rsif.2020.0070
Entities
People
- Babak Eslami
- Mark Ilton
- Ryan St Pierre
- Sarah Bergbreiter
- Sathvik Divi
- Sheila Patek
- Xiaotian Ma
Organizations
- Army Research Office
- Carnegie Mellon University
- Duke University
- Harvey Mudd College
- Widener University