So a lot of stuff has happened since our last post…with spring break + our first competition, we’ve been pretty busy, but here’s a run-down of everything has happened.
We finished the robot. This was a complete turnaround from last year, as we finished a couple days before the competition, and actually had driver practice and programming being able to do their thing before being at the actual competition.
Here are some pictures of the finished robot.
We’re really, really proud of how it turned out.
Let’s start with individual systems.
First off: ball transport. We found a 4-bar, easily collapsible intake worked best to be quick and effective in sucking up cargo. This was the first thing we finished and tested on the bot, and it worked pretty well. Some iterations we had involved changing the third bar from a roller to a row of compliant wheels, as we found it was contacting the balls a lot more than we thought it would and the compliant wheels would work better for this. This intake worked well through our first competition, but we noticed that those VIW at the front usually didn’t really pick up the balls as much as we wanted them to, and didn’t vector that well at the front. So, after the competition, we switched the 1st and 2nd bars, and have found much increased performance of the intake. Our elevator system also worked really well to both raise the cargo and bring them up to speed to shoot. The passive singulator performed as well. Here’s a video of our intake in action.
https://drive.google.com/file/d/14GqjDCaAS6LEJhhjKYXRlkcDNS61VhLJ/view?usp=sharing
Next: shooting. The eventual goal with our shooter (fixed angle dual wheel) was to adjust both wheel speeds and change the trajectory of the ball in real-time using the limelight to measure distance from the hub. This would let us shoot from a decent range. For Channelview however, we thought it was more realistic to go with a fender upper hub shot, and this worked well. It took an hour or so to get the right values, and then after that we just had a single button that started a shooting “sequence”: reversed the elevator (to get the balls away from the wheels as they spin up), spin up the wheels, and then shoot the elevator back up.
This can be observed at about the 40-second mark in this match video.
https://drive.google.com/file/d/1EUfSpflfx5jf9V195GP11TAYSgM3gcoh/view?usp=sharing
Lastly, the climb system. This was definitely both the most problematic and impressive part of our robot. So initially, upon testing the climb, we noticed that swinging from one bar to the next would hyperextend the climber arms backwards. Because we didn’t have any sort of hard stop, and because the support going from the climber arm to the pneumatic cylinder (see below) was connected with a small T-gusset, this connection completely deformed under the hundreds of pounds of force from the swing.
The other issue was that these bars coming off the climber were riveted into the tube, and these rivets were interfering with the telescoping of the tube. This is when we decided to scrap that bottom tube.
BEFORE
AFTER
To fix this, we added some redundancy because this would decimate our chances at competition. We added giant triangles that were clamped on with bolts on the outside instead of rivets (to allow for smooth telescoping), and added hard stops that should prevent force from ever even going to that connection. These can be seen in the robot pics at the top of the post.
Finally, as far as autonomous goes, we had a somewhat jank 3 ball autonomous before the competition, but we decided our super reliable 2 ball was more appropriate, especially because it would aid super strong alliance partners with 5 ball autos.
With all these upgrades and working systems, we had a really, really good competition. We won every qualification match save 1, and ended ranked 2nd behind team 118 Robonauts. In alliance selection, we were first pick of the robonauts, to which we graciously and somewhat humorously accepted (see recap video), and went undefeated in the playoffs to our first ever blue banner victory in the finals. This was an amazing experience for everyone on our team, and we definitely celebrated afterwards. What made the whole experience even more insane, was that winning + only losing 1 qualification match + winning the industrial design award left us with 67 + 5 = 72 district points, tying us for SECOND in the extremely competitive state of Texas. But it got even better. Being a second year team, we got a 5 point bonus to our score, actually putting us as rank #1 in the state of texas. We basically couldn’t believe our eyes for a solid week, and walked around in a daze.
Overall, our second-ever complete competition was an extremely gratifying and rewarding experience, and it felt a little surreal to be the team that everyone was trying to defend in matches.
Here’s a couple of pictures from the competition along with the recap video.
see you guys at pasadena #2!
