kwc.org Photos Spare Cycles MythBusters

Single memory bug takes down Princeton's DARPA Grand Challenge entry

correction: this occurred in the 2005 Grand Challenge, not the 2007 Urban Challenge.

There's a short article from Princeton team member Brian Cattle on how a memory leak caused their Urban Grand Challenge entry to fail. In their testing, the system would fail after 40 minutes. Not knowing what to do, they set the code to restart itself every 40 minutes -- sounds good, right? During the actual event their car failed after 28 minutes. Doh!

The article is essentially a marketing piece for the ANTS Profiler, while writeups over at robots.net and Slashdot are trying to blame Princeton's choice of C# and Microsoft Robotics Studio. I'm happy to use profilers and bash Microsoft, but in this case their bug was programming mistakes 101: they subscribed objects to events and neglected to add the one line of code to remove subscriptions when those objects were deleted.

In Princeton's case the objects were the obstacles that the car was seeing. In their testing, it would take 40 minutes to see enough obstacles to cause their problem. The DARPA course had more obstacles and caused a failure in 28 minutes.

Post a comment


related entries.

what is this?

This page contains a single entry from kwc blog posted on November 19, 2007 2:46 PM.

The previous post was Pirate Videos.

The next post is Robot-y Tokyo recommendations.

Current entries can be found on the main page.