The design of a Hall Effect force sensing flexure on the front leg of a robotic cheetah

To successfully design and program legged robots, it is important to be able to characterize the forces felt on the moving joints. To achieve this, we designed an easy to implement force sensor that used Hall Effect sensors mounted on a flexure to measure force. The flexure was designed to be compliant in two directions, along the ground normal and shear reaction forces. The Hall Effect sensors were mounted so that the change in position of a magnet on the sensor translated to a change in position. By relating this data, the voltage output of the Hall Effect sensors could be related to force through a calibration matrix. The flexure was prototyped at a large scale of 5 in x 5 in x 7 in. The force sensor behaved as expected in compression but abnormally when encountering large shear forces, causing a discrepancy in the calibration matrix. Moving forward, tightening tolerances on the flexure and modifying the Hall Effect sensor setup to use 2- axis sensing for both compression and shear directions should decrease the error between calculated and actual force measurements, allowing for a reliable calibration matrix to be calculated.

Department dc:contributor.department

Massachusetts Institute of Technology. Dept. of Mechanical Engineering.

Grantor dc:publisher

Massachusetts Institute of Technology

Year dc:date.issued

2011

Author dc:creator

• Blakemore, Andrea L. (Andrea Leigh)

Advisor dc:contributor.advisor

• Sangbae Kim.

• 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/1721.1/69503

OAI identifier oai:identifier

oai:dspace.mit.edu:1721.1/69503