Motion-Logger: An Attitude and Motion Sensing System

This thesis proposes a motion sensing system for wheelchairs with the main objective of determining tips, falls and risky situations. The system relies on measurements from an Inertial Measurement Unit, (IMU), consisting of a 3-axis accelerometer and a 2-axis gyroscope as the source of information. The IMU was embedded in a portable device, the "Motion Logger", which collects motion data in a Secure Digital memory card after running a real time preprocessing algorithm. The algorithm was designed to reduce energy consumption and memory usage. Actual signal analysis and attitude estimation is carried out offline. The motion sensing system was developed for determining wheelchair-related falls as part of a major research effort carried out at the research center of the James A Haley VA Hospital Subject Safety Center, Tampa, Florida. The focus of the study concentrated on achieving a thorough understanding of the demographics, nature, consequences and the creation of prediction models for fall events. The main goal of the embedded system was to successfully estimate the motion variables relevant to the occurrence of falls, tips and similar risky situations. Currently, off-line smoothing techniques based on Kalman filter concepts allow for optimal estimation of angles in the longitudinal direction, roll, and in the lateral direction, pitch. Results from both predefined experiments with known outcomes and data collected from actual wheelchair users during pilot and final deployment stages are presented and discussed.

Grantor dc:publisher

Digital Commons @ University of South Florida

Year dc:date

2008

Author dc:creator

• Marquez, Andres Felipe

• Attitude estimation
• Kalman filter
• Inertial Measurement Unit (IMU)
• Accelerometers
• Gyroscopes
• American Studies
• Arts and Humanities

Statement dc:rights

• default

Repository record dc:identifier

https://digitalcommons.usf.edu/etd/377

OAI identifier oai:identifier

oai:digitalcommons.usf.edu:etd-1376