View Single Post
  #1   Spotlight this post!  
Unread 11-06-2014, 04:16
asid61's Avatar
asid61 asid61 is offline
Registered User
AKA: Anand Rajamani
FRC #0115 (MVRT)
Team Role: Mechanical
 
Join Date: Jan 2014
Rookie Year: 2013
Location: Cupertino, CA
Posts: 2,224
asid61 has a reputation beyond reputeasid61 has a reputation beyond reputeasid61 has a reputation beyond reputeasid61 has a reputation beyond reputeasid61 has a reputation beyond reputeasid61 has a reputation beyond reputeasid61 has a reputation beyond reputeasid61 has a reputation beyond reputeasid61 has a reputation beyond reputeasid61 has a reputation beyond reputeasid61 has a reputation beyond repute
Re: Why is swerve so slow?

Quote:
Originally Posted by Tyler2517 View Post
Speed is a interesting concept and a top speed is a really weird way to state it.
We ran swerve this year using something almost identical to what 1640 uses. We ran something at like 12.5-13.5 fps single speed. Acceleration matters much more when you are supper maneuverable in a tight space then when you just want to out run your competition. We wanted something just above the median speed range but not so fast that we would never reach the speed. So a acceleration that we can reach top speed in about 3ish robot lengths. The key is not to be to fast to out run your opponent nor to slow only be where you need to be in such a way that it would appear effortless.
https://www.youtube.com/watch?v=Lpb2...DIBcQ&index=37
Us team 2517 were always where we needed to be to play defense in just the right time in such a way that it would be hard to see where we were going.

Now there is some cool things you can do with swerve that make it appear that you are travailing much slower then you really are. By making small circles where a normal tank drive would drive back then ram you can be essential ramming at full speed even though it takes up the same amount of space as a tank drive would take to break and start moving again.
Exellent driving in that match! You definitely look faster than you are.

Thinking about acceleration, if you could take the battery load then you could "warm up" the motors by spinning in place until it's time to move.

One thing to note is that acceleration apparently barely changes from 10fps to 20fps. One parent on our team made me a spreadsheet (with graphs) that detailed acceleration given motor specs and robot weight, although it did not include friction in the calculations. It showed that for speeds up to ~30fps the distance vs. time was almost the same. By going at lower speeds you would get an advantage on the order of a few inches.

Increasing the number of cims did help acceleration a lot, but nothing else except robot weight helped that much (according to the spreadsheet).