Projects

The projects here are mostly for historic interest, as I can't really talk about all the cool stuff I work on at my current employer.

World's Smallest Autonomous Robotic Stair-Surmounting System

Scouts are cylindrical robots just 10 cm in length with only rudimentary computational resources. The lack of intelligence necessitated the use of either teleoperation, which fatigues the human operator quickly, or undesirable open-loop control. By tracking a Scout with an external camera using topologically adapting snakes and relaying control commands to the robot, I was able to create the world's smallest autonomous robotic stair-surmounting system. The Scout situates itself at an advantageous position and subsequently jumps onto the next step, as demonstrated in a short video (89 s). The steps only appear big in comparison to the robot; they were constructed according to building codes.

The robot was also most notably featured on Slashdot, The Daily Show with Jon Stewart, CNN Headline News, and the BBC in a program — oops: programme — titled "Seven Ways to Topple Saddam".

Topologically Adapting Snakes

I have improved the tracking performance of active contour models by allowing snakes to split and merge. This can be useful for handling occlusions (e.g., pedestrian tracking) and objects that undergo topological changes (e.g., globule in a liquid motion lamp). Enjoy the relaxing video (14 s).

Distributed Software Architecture for Heterogeneous Robot Team

Wrangling a large number of heterogeneous mobile robots is a tough challenge that can only be alleviated by introducing intelligence. In order to optimize usage of the available resources, I co-led a team to design and implement a distributed software architecture, allowing the robots to communicate with each other and the human operator. By hiding the system's complexity in the CORBA-based middleware, our group was able to quickly create autonomous applications that proved themselves in realistic tests by the U.S. military. The architecture employed XML to describe the varying capabilities of robots, rather than write yet another parser for a proprietary description language, as was the standard then. The UML diagram depicts the component startup.

Regrasping

Manipulators in contemporary workcells are optimized for fast throughput by employing part feeding mechanisms and assuming single-grasp operations. This approach is ill-suited for unstructured environments, in which no guarantee for the initial placement of parts can be made. Several grasps may be required to achieve the goal pose. In this project, my partner and I developed a framework for automatically generating a sequence of grasps to transfer a part with known geometric properties from its initial pose to the desired pose. Regrasping provides manipulators with increased flexibility to handle unforeseen situations.

Gmail SMS Notifier

Living in Switzerland prevents me from forwarding new Gmail messages to my mobile phone as an SMS. Local cell phone providers don't assign email addresses to the number. A small Python script gluing libgmail with the Skype API on a Mac using PyObjC makes it possible. It needs a lot of work (hey, it's my first Python script and it's late), but the basic functionality is available. Thanks to Jaanus and his code that got me started. Download the script and run it as python GmailSmsNotifier.py -h to obtain usage information.

University of Minnesota LaTeX Thesis Package

Because the University of Minnesota's Graduate School does not provide a template for the dissertation, I created a simple LaTeX package myself. I tried to follow the at times self-contradictory and confusing formatting guidelines as closely as possible. (Could this be the reason the U lacks an official style?) Several options (e.g., spacing) can be selected in the main file umnthesis.tex. Templates exist for mandatory pages (title, copyright, etc.) that are output in the correct order. To start writing your thesis, download the file umnthesis.tar. Feel free to use and distribute it.