Attila is a robot that competed in NASA's 2009 Regolith Excavation Challenge
During 30 minute tests it was able to excavate over 1000 lbs of sand. It didn't win, but it dug through regolith like moon dirt flavored pudding.
Competition Results and More...
Oct 28 2009
It has been 10 days since Attila made his official competition attempt. I'm sad to say the attempt wasn't a success. An immediate stop was added to make the drive motor turn off slightly faster when the reversing limit switch was depressed. The reason this was added was that the momentum of the robot while fully loaded caused it to bang into the wall with considerable force even after the motor was no longer powered. This code was added just before the robot was carted off to the competition. We didn't want to perform more digging tests since we had no more actuators available, and two digging actuators had previously failed during testing. This small code change was simulated in software, but the switch being depressed the first time while the robot was started against the wall caused the robot not to reverse after its first dig - thinking it had already completed a reverse cycle since the switch was set.
I'd like to thank our sponsor, Automation Direct for helping out with the entrance fee.
Our robot ended up on the front of the Popular Science article about the competition. (I guess they thought it actually looked like a digger).
A good video of some of the competition attempts and also Attila digging and lifting regolith is in this New Scientist article.
This video is also overdue, but here is our competition submission video:
The deadline for all teams to submit a video doing a full cycle of digging and dumping was today. We mailed a CD in prior to Matt giving an FTP login for video submission, but we submitted our video both ways. The final team count looks like it has ended up at 23.
We've been doing a lot of testing over the past week, and are still trying to optimize the performance of Attila. It is important that all little problems that can occur pop up during testing instead of while at the competition. We will probably be testing and fine tuning all the way up until we leave for the competition.
Just got back from the beach this morning, here are the results of our backup push mechanism dealing with a large load in front of it. This mechanism is designed to be used in case during the competition we have multiple rocks in the way of our excavator.
Posting some new videos today, the first video shows a test for pushing objects and two digs. The second video shows and automated dig cycle. We are going to the beach today to test our push and hopefully improve it.
Today was our first test with Attila on the beach rather than in a sand pit in our backyard. The test was quite successful and we were able to dig large amounts of sand. We had a little bit of trouble with slippage of the belt on our turn table mechanism. In addition, we tested using our old wheels first and were unable to test the newer wheels under threat of rain. The old wheels performed fine in shallow sand, but when we got down further on the beach they were just spinning and sinking in. Based on this experience with the wheels we're building a new set that is wider and won't sink. In digging such a large load our bucket actuators suffered from a lot of deflection, so we need to come up with some mechanism that prevents them from being deflected and possibly damaged. Here's the video from our test and some video of the robot pushing weights across our carpet.
We're trying to redesign our power system in order to get more watt hours per kilogram. Previously we had been using low quality lead acid batteries, but we are switching to batteries with a higher energy density. We also installed new aluminum wheels that are much lighter than our previous wheels, but we haven't tested their performance yet. Earlier in the week we had some machining work done on an aluminum gear for our motor. The weight savings of switching out steel components to aluminum components is worth it.
The Attila Robot site launched today. So far Attila is in good standing.
The main issues our team has faced so far have been related to trying to strike a balance between weight, power, and cost. An additional challenge we have faced is not having a real machine shop to work in, so we're doing the majority of work out of our dining room (it'd be nice to have a CNC machine). We are really looking forward to the competition in October!
