Efficient control of series elastic actuators through the exploitation of resonant modes

This thesis explores the efficiency potential inherent to series elastic actuators during oscillatory tasks. Series elastic actuators have a spring intentionally placed at the actuator output that provides good force resolution and filters out high frequency disturbances from the environment. These properties are essential for robotic applications in which interactions with the environment are unknown, because they allow the actuators to maintain stable force control while protecting the drive train from harmful loadings. The spring can also be used to store energy similar to the way animals use their tendons during locomotory tasks. This thesis shows that by operating the actuators at the appropriate frequency, the storage of energy by the springs can be translated into large efficiency gains for the actuator. To show the efficiency gains of the actuator, a control scheme was developed that is capable of operating the actuators at and above their resonant frequency. The control scheme was based on spring force control allowing it to provide protection to the drive train while being robust to changes in link inertia due to manipulator configuration or environmental interactions.

Department dc:contributor.department

Massachusetts Institute of Technology. Dept. of Mechanical Engineering.

Grantor dc:publisher

Massachusetts Institute of Technology

Year dc:date.issued

2007

Author dc:creator

• Albert, Kevin B. (Kevin Bjorn)

Advisor dc:contributor.advisor

• Hani Sallun and David Trumper.

• Mechanical Engineering.

Statement dc:rights

• M.I.T. theses are protected by copyright. They may be viewed from this source for any purpose, but reproduction or distribution in any format is prohibited without written permission. See provided URL for inquiries about permission.

Licence dc:rights.uri

• http://dspace.mit.edu/handle/1721.1/7582

Language dc:language.iso

eng

Handle dc:identifier.uri

http://hdl.handle.net/1721.1/39743

OAI identifier oai:identifier

oai:dspace.mit.edu:1721.1/39743