cis541 (GPS Node Kit & ElBrainOh)

Mar 2004 – May 2004 · age 22

What it was

A five-person senior software engineering project at Kansas State: make a Pioneer robot drive itself across campus by GPS. The hardware said no. GPS was off by fifteen meters and the sonar reached three, so localization, the original goal, died in the second iteration. The team pivoted to two tools. GPS Node Kit, a C# editor Jeff wrote, let a human draw drivable rectangles over an aerial photo of campus and compiled their overlaps into a route graph. ElBrainOh, a C++ brain, loaded that graph, found the shortest path, turned it into queued turn-and-move commands behind a Command interface, and drove the robot by counting its own steps. Jeff led the research subteam and wrote the command structure and the editor. The documentation was written straight through the night and finished at 6:35 on the morning it was due.

Wins, for the age

• At twenty-two, arrived at a navigation mesh drawn by hand over a satellite image, the idea games had already adopted around 2000, found here from pure necessity.
• Georeferenced the photo from a few hand-typed GPS fixes by averaging every pair, landing within half a percent of isotropic. The team had never heard the word "georeferencing".
• Led a split team, wrote down who did what, and put "Goals Failed" in a slide heading instead of burying it. Most young apes hide that slide.
• Connected two programs in two languages with a visual-path file, the cheapest simulator possible, so the planner could be tested without the robot.

What it taught

• When the hard problem cannot be solved with what you have, reframe the deliverable so the semester is not wasted.
• The seam is the design. The Command and Factory structure left room for the GPS and sonar corrections the team did not have.
• Coordinate frames are where the bugs live: pixels with y down, degrees, meters and headings that wrap.
• Build a tool to make the data for the other tool.
• Crunch works often enough to become a habit, which is exactly the problem with it.

Genealogy

Ancestors: none on record. This is the first project in the graveyard with more than one author. Descendants: Defense Map Ed: paint the walkable map, and shortest paths come out.

Epitaph

Here lies Team 13's robot, which could never know where it was. So the humans drew it a map, and it walked the path counting its own steps.