Here is an update from the team regarding the "rocking while turning" problem:
"In our effort to determine why our robot 'dances' when it turns quickly, our first test was to find the horizontal center of mass/gravity (c.g.)
To our surprise, we found the c.g. to be very close to the center of the middle wheel. It is about 1" forward of the center wheel, as determined by balancing the robot on blocks.
Instead, we believe the problem is in the distribution of the mass.
The mass has large densities like below:
(S)---
|
|
|
|
|
----(B)
where (S) is the shooter, and (B) is the battery.
While the mass distribution is more complicated, the point is that as we rotate about the center vertical axis, the shooter wants to tilt the robot forward, and the battery wants to pull the back outward.
_-\
(S) \
\
\ _(B)
\-
In short, we need to pay more attention to the mass distribution for dynamic balance. While we are well balanced statically, our 2012 mass distribution results in poor dynamic balance."
Hopefully this can provide some new insight into this issue. There are so many complications that make creating a stable and smooth drivetrain harder than it seems
