DARPA Grand Challenge 2005 Revisited

In 2004-2005, I become involved with a Colorado based group, Team Mojavaton, who were competing in the first DARPA Grand Challenge for autonomous vehicles to navigate a course entirely without driver assistance. This was a very modestly, primarily privately, funded team. We (at Optech at that time) provided one of our ILRIS lidar scanners (look carefully on the roof of the vehicle) and software to collect and analyse 3D data during the drive. Team Mojavaton was one of 23 finalist teams in the 2005 event. They had a strong entry; their vehicle, dubbed “The White Knight”, actually passed 10 other vehicles. This was an impressive achievement given the race format, which used a staggered start. Unfortunately, the vehicle suffered a simple mechanical failure in the throttle control, and coasted to a stop in the middle of the road, still on course, with all of the other systems functioning.

Today, I came across this article about the Carnegie Mellon (CMU) entry's heavily funded vehicle, and how it failed because of a simple electronic filter. Last week, CMU celebrated the 10th anniversary of BOSS' DARPA Urban Challenge win in 2007. The vehicles, BOSS, Sandstorm, and H1ghlander, were all pulled out of storage at CMU and tidied up a bit to be put on display. As H1ghlander's engine compartment was being cleaned with the engine running, Spencer Spiker (CMU's operations team leader for the DARPA challenges) leaned against the engine with his knee, and it started to die. The box is a filter that goes in between the engine control module and the fuel injectors, one of only two electronic parts in the engine on a 1986 Hummer. Spencer discovered that just touching the filter would cause the engine to lose power, and if you actually pushed on it, the engine died completely. But, from a cold start, if the filter wasn't being touched, the engine would run fine. There was nothing wrong with H1ghlander's sensors, or software: this filter cost H1ghlander 40 minutes of race time, and the win. "How about that, buddy!" William "Red" Whittaker said to Chris Urmson (who was working on perception for Red Team during the DARPA challenge, and ran Google's self driving car program for seven years before starting his own autonomous vehicle company) at the CMU event, showing him the filter. "You're off the hook!" 

This once again points out how often the weakest link in any complex system can be the simplest component that may have been overlooked. In CMU's case it took 12 years.