View Single Post
  #7   Spotlight this post!  
Unread 03-12-2007, 14:26
JesseK's Avatar
JesseK JesseK is offline
Expert Flybot Crasher
FRC #1885 (ILITE)
Team Role: Mentor
 
Join Date: Mar 2007
Rookie Year: 2005
Location: Reston, VA
Posts: 3,658
JesseK has a reputation beyond reputeJesseK has a reputation beyond reputeJesseK has a reputation beyond reputeJesseK has a reputation beyond reputeJesseK has a reputation beyond reputeJesseK has a reputation beyond reputeJesseK has a reputation beyond reputeJesseK has a reputation beyond reputeJesseK has a reputation beyond reputeJesseK has a reputation beyond reputeJesseK has a reputation beyond repute
Re: Mecanum Drive - Help

Quote:
By using the (much slower) sideways motion for distance movement, they effectively lowered their scoring potential.
There should be no reason a mecanum drive moves sideways slower than it does forward/backward, unless the team was using rollers that were a.) not at 45 degrees or b.) tightened to gain more forwards/backwards grip at the cost of sideways speed or C.) flawed via code that wasn't producing the maximum PWM signal when it should have been -- I saw that in a VEX algorithm at this weekend's Va. FTC tournament. In either case it was a design decision that also hurt them in their implementation, not necessarily just the driving decisions.

Ideally, mecanums should be able to produce truely holonomic drive trains; FRC simply lacks the processing on the controller to properly calculate the unit vectors for smooth movement. As a reault most teams settle for a 16-sector lookup table or dump that altogether and stick with robot-centric (normal skid + a bit of lateral sideways movement).
__________________

Drive Coach, 1885 (2007-present)
CAD Library Updated 5/1/16 - 2016 Curie/Carver Industrial Design Winner
GitHub

Last edited by JesseK : 03-12-2007 at 14:30.