pic: Big Mouse 2

[Aldabe]

loading photo ...

[Graham Donaldson]

Heaven forbid that I seem uneducated/dimwitted/not seeing the obvious, but what exactly does it do?

[Tom Line]

It's a mouse ball - or it works along the same principle. When the robot moves in the x, the ball rotates in the x and turns an encoder. Likewise in the y. In this manner, they use the mouseball for absolute positioning and use the gyro for heading.

[Tottanka]

so it is supposed to touch the ground at all times?
what about the bump under the overpass?

[Dad1279]

Brilliant!

[artdutra04]

Originally Posted by Tottanka

so it is supposed to touch the ground at all times?
what about the bump under the overpass?

It looks like there are compression springs around the four bolts holding it onto the chassis.

[EricH]

Originally Posted by Tottanka

so it is supposed to touch the ground at all times?
what about the bump under the overpass?

The lane divider bump shouldn't do a whole lot.

What's this about a bump under the overpass? Is there something I missed?

[GaryVoshol]

Originally Posted by EricH

The lane divider bump shouldn't do a whole lot.

What's this about a bump under the overpass? Is there something I missed?

This is what you evidently missed:

6.2.3 The LANE DIVIDER
The TRACK is divided by a LANE DIVIDER that extends along the major axis of the TRACK. The
LANE DIVIDER is six feet tall and approximately 27 feet long. It is constructed of 1-1/2 inch O.D.
steel pipe and connecting hardware, forming railing panels. The openings in the railing panels are
filled with clear plastic to prevent portions of ROBOTS from inadvertently passing through the
structure. The LANE DIVIDER is attached to vertical posts that are anchored to supporting plates
covered by carpet. Note that these plates will create a bump in the carpet approximately 1/2 inch
tall, and as a result the surface of the TRACK will not be perfectly flat. ROBOTS must be designed
to accommodate these surface variations. The LANE DIVIDER is attached to the floor such that it
should remain vertical and not move when struck by ROBOTS.

(emphasis mine)

[IbleedPink233]

I like it - it is very clever way to track position in hybrid (maybe teleop, too?) - hopefully eliminating the issue of wheel slippage with encoders on drive wheels. Seems perfect for swerve drive control, especially (which I don't think you have, but I could be wrong).

By the way, I thought that I'd make the blatantly obvious Trackball observation.

[EricH]

Originally Posted by GaryVoshol

This is what you evidently missed:

(emphasis mine)

Is that under the Overpass? No. It's under the Lane Divider, only part of which is under the Overpass. The reason I was asking what I'd missed is that there isn't a bump under the Overpass in the manual at all, other than the lane divider one, which shouldn't affect play very much, if at all. Tottanka is an FTA, so he'd know if there was a bump that wasn't called out and should have been.

I knew about the lane divider bumps already.

[GaryVoshol]

OK, I assumed they meant the lane divider bump that is even with the overpass. Yeah, that's my story, and I'm sticking to it ... I didn't misread the question.

I recall another BUSTED myth, that there would be a slight bump at the finish line. Someone's depth perception was thrown off by the checkerboard pattern.

[Manoel]

Originally Posted by IbleedPink233

I like it - it is very clever way to track position in hybrid (maybe teleop, too?) - hopefully eliminating the issue of wheel slippage with encoders on drive wheels. Seems perfect for swerve drive control, especially (which I don't think you have, but I could be wrong).

Oh, it swerves.

We are using it in teleoperated mode as well to keep the robot driving/strafing straight. Hopefully everything is going to work in a crowded field!

[JM987]

Originally Posted by GaryVoshol

OK, I assumed they meant the lane divider bump that is even with the overpass. Yeah, that's my story, and I'm sticking to it ... I didn't misread the question.

I recall another BUSTED myth, that there would be a slight bump at the finish line. Someone's depth perception was thrown off by the checkerboard pattern.

Just stop haha, geez relax man

[MDiff]

I like it a lot!
Looks very cool, and the nerd in me loves that it's a trackball
Although does it come with the same problems of a trackball? Get dirt in there and it fudges up

I noticed the springs to keep pressure forward, but it has something that restricts that movement right? as to not get very weird when lifting the robot
Speaking of which, i noticed you guys have mecanum (or we're assuming you do), have you ever run into the issue of having come off the floor having hit a corner too quickly and have the trackball skip any?
or is it only for autonomous?

sorry for the confusing sentence structure...

[Manoel]

Originally Posted by MDiff

I like it a lot!
Looks very cool, and the nerd in me loves that it's a trackball
Although does it come with the same problems of a trackball? Get dirt in there and it fudges up

I noticed the springs to keep pressure forward, but it has something that restricts that movement right? as to not get very weird when lifting the robot
Speaking of which, i noticed you guys have mecanum (or we're assuming you do), have you ever run into the issue of having come off the floor having hit a corner too quickly and have the trackball skip any?
or is it only for autonomous?

sorry for the confusing sentence structure...

Well, it's not a trackball, it's a standard, COTS billiard ball. It does get dirty so we will be checking on it before each match.

Neither the mouse nor the ball will fall off of the robot if it's lifted.

The entire structure is compressed about two inches by the springs, so small bumps shouldn't really make us lose contact with the ground.

We do plan on using it for teleoperated mode, but the driver has the possibility to turn off all automation and drive unassisted if he wants to.