When we finally started to drive our robot around i thought hey we were going to be pretty fast, and mobile. I give my self a pat on the back here (i am head of power train design). but then we attach the trailer. We seem to be a lot slower, this was expected to some degree (pulling 40 pounds around tends to do that) . but the thing that has me worried is while we can make really sharp turns it is really slow and normal wide turns are hard to use when aiming. i just want to know is this common with other bots or is it just us???
we have a 4 wheel independent tank style drive train with traction control.
When I drive the bot without the trailer I find it a lot easier than without. Yes it does slow us down substantially but it also adds some stability among other things. The trick I found it to always keep the trailer moving and use it like a counterweight to help you turn and other things. Also when changing directions (backwards to forwards) you can use the trailer as a point of rotation and do a 180 if you stay on the sticks right.
Btw, We have a wide base 6wd. (similar to a wide base 4wd)
I’m the primary driver for our team, and we just had a scrimmage yesterday.
It taught us a lot, like, if you want to turn really sharp, you can’t. the closest we got was starting a sharp turn, then pushing the joystick forward a bit.
we have a 4wd NARROW base, skid-steer chassis, and it seems like that was a bad idea, as it seems a lot harder to turn.
even so, the regolith impaired everyone a lot more than they expected, and even the big, wide-base bots were really easy to push around (it seems like wide bases turn better, but narrow bases push a lot better.
we also saw a lot of shooters die. they seemed to completely loose accuracy once the bands in the balls started breaking (by the end of the first scrimmage match [on a half field, only 3 bots] EVERY ball had at least one band broken, and by the end of the third match, most had 2 or 3 broken)
another thing we noticed, was that shooters seemed to jam alot if the bands in the balls broke.
We’ve been using broken balls for testing our robot, so we’re pretty well used to the broken ball jamming/shooting problems. We’ve gotten our robot to work well with balls with only 1 or 2 broken bands, but when they get 4 or more they start to cause problems.
Having the trailer seems to affect our driving on the FRP in an interesting way…we only have 3 sheets, and only enough carpet for that much, so we can’t even turn the robot around on the FRP with the trailer on it (our test area is 8 x 12 feet). I guess our driver will learn a lot Thursday of our first regional!
ma favorite way to turn is to put the robot in full speed reverse, jacknife the trailer, and watch it slingshot the robot around. once the bot gets to the halfway point of the turn, throw it into full forward (bad for the cims i know… :mad: ) but, EXTREMELY effective for turning really fast, and getting away…
at the scrimmage, most shooters were having troubble getting more than a coupple balls in another trailer in a row.
however, our team has a dumping robot, and our reckord was getting 6 balls into another trailer at once ***(beu, er failed at repeating it…)
on average, we got 3 or 4 balls in each time we dumped…
This has been my experience with tank drive with programmed traction control limiting acceleration. An important thing to note is to practice backing up with a trailer. The trailer will go the opposite way you initially back up (as it does on a car), so you need to account for that when driving.
The first time putting the trailer on the robot it was so much harder to drive. We were in the court yard of one of our buildings and our driver actually did not feel comfortable driving thinking that he might break a window. (the building is surrounded by windows) It affected our driving a lot
yea we used last years robot (“lappy”) to test our trailer and it did slow him down a bit but it wasn’t to bad, our turns are alil hard to do though =/ other than that everything seemed normal
With about half a field’s worth of Regolith so far for the Rochester Rally tomorrow (ha actually today now ;), and finally fixing our belt problem, I can only say that this is the most fun driving that I have ever had. We have a 4 wheel, wide base, tank drive, and the trailer actually seems to make turns easier. I am able to make pretty sharp turns, and I can actually still do burnouts quite fast. Once you get the hang of using the weight and force of the trailer to whip your robot around turns, you’ll see what I mean. Its awesome!
So far, for us the biggest issue with the trailer hasn’t been slippage(he have an accelerometer-based TC system that handles that pretty well), but its impact on driving backwards. Our plan is to use a gyro to compare ideal versus actual heading and corect accordingly, but we’re having trouble integrating it with the tank drive:ahh: :ahh: :ahh:
612 is using front wheel steering on our robot and it has improved our driving abilities with the trailer a lot as opposed to using tank drive. It is really interesting because robots don’t have the ability to turn on a dime anymore. So it some ways it plays to our advantage when we are trying to anticipate another robots movement when we are trying to score and hurts us when others are scoring on us. But it is a lot of fun to see that robot drifting all around the field.
