Research

My research interests include feedback control design, robotics, and locomotion. Some of my projects in these areas are described below.

Bipedal Robot Locomotion

This project, directed by Prof. Jessy Grizzle, aims to devlop robust control strategies for efficient, agile locomotion by bipedal robots.

Some preliminary outdoor walking results are described in a recent University of Michigan news article.

This material is based upon work supported by the National Science Foundation through an NSF Graduate Research Fellowship.

Any opinions, findings, and conclusions or recommendations expressed in this material are those of the author(s) and do not necessarily reflect the views of the National Science Foundation.

Modeling and Control of Blood Glucose in the Critically Ill
Feedback diagram for glucose control in the ICU

Critically ill patients often present poor glycemic regulation. To manage glucose in the ICU, many hospitals use continuous insulin infusions adjusted according to a written protocol. Such protocols are usually developed by trial and error, and many different protocols are in use.

This project, directed by Prof. Jessy Grizzle and Roma Gianchandani, MD, aims to improve ICU outcomes by facilitating better glycemic control. Our approach invovles the development of a patient simulation model. This model can be used to compare, evaluate, and adapt a protocol, whether written or computerized.

The model and some initial protocol improvement results were presented in a poster at ENDO 2011: The Endocrine Society's 93rd Annual Meeting and Expo. Click on the image below to view a copy of the poster.

Click for ENDO 2011 poster

This material is based upon work supported by the National Science Foundation through an NSF Graduate Research Fellowship.

Any opinions, findings, and conclusions or recommendations expressed in this material are those of the author(s) and do not necessarily reflect the views of the National Science Foundation.

Predictive Modeling of Lost-Person Behavior

As an undergraduate student at Brigham Young University I benefitted from the mentoring of Dr. Michael Goodrich in a project focused on helping search and rescue teams quickly locate victims lost in the wilderness. I was first attracted to this project because of my experience as a volunteer on the Utah County Explorer Search and Rescue team.

Map showing most likely places the victim might be found according to an experienced searcher

I studied mathematical structures which could be used to model wilderness environments and human agents. I then developed probabilistic models for the movement of a lost person in unfamiliar terrain and researched techniques for statistical modeling and analysis. Most of the techincal work involved simulation and analysis in MATLAB.

However, as part of a larger team developing technologies to enable the use of unmanned aerial vehicles (UAVs) for search and rescue, I also advised professors and other students on factors relevant to search and rescue and helped coordinate and carry out field testing of new UAV technologies.

Laser Rangefinder Obstacle Detection and Tracking

As part of the DARPA Urban Challenge team at Brigham Young University, I led the laser rangefinder team. We researched and implemented feature extraction algorithms for use with rangefinder point data. This work required also a study of environmental modeling and mapping techniques. We developed a feature correspondence algorithm for tracking objects temporally in sensor data. The guidance of Dr. D.J. Lee improved our efforts and inspired me to pursue further education.

Diagram of one potential sensor configuration
Scanning Impedance Imaging

Under the mentorship of Dr. Aaron Hawkins and Dr. Stephen Schultz I aided in the analysis, refinement, and testing of a system for imaging based on electrical impedance. An XYZ stage scanned a small probe over a sample such as a cluster of cancer cells or a butterfly wing (shown), measuring the impedance in a fine grid. I performed numerous experiments and designed scan control software and analysis tools.

Impedance images of a group of cancer cells and of a butterfly wing