Our team is designing a support robot, whose goal is to grab balls, traverse the defenses, and bring the ball to team mates who shoot. As such, we’re designing for speed, low to the ground, and the ability to handle defenses. We’re also going to try to hang.
The current plans are as such:
Low body using 6WD tank drive on Pneumatic wheels.
Ball-capture will be a pair of ‘pincers’ located on the front of the bot, which will actuate out and in to grab the balls with a largish half/dome shape. Once captured, it will actuate back a bit to lift the ball up to avoid contacting the ground will traversing. While not in use, these pincers will fold back over the main bot body for storage and to make sure they don’t get jammed up on things.
Primary manipulator for the gate/sally port/draw bridge is a ‘tail’ . This tail will be driven by a chain drive and mounted on rods that span the length of our bot, allowing it to travel back and forth. This should allow us to, for example, hold the gate up and drive under neath it, keeping the ‘tail’ steady while our chassis goes under. Same idea for the sally port, and will allow us to lift our chassis up faster too we’re hoping.
Your strategy look pretty viable. That’s probably what i’d do being on a rookie team with low ressources/experience.
Basically you want to grab balls and interact with defenses using 2 different “arms”. Do you think a single, stronger mechanism could do both tasks? Could you also find a way to score low goal with that same mechanism? There is so much stuff to think about
On a final note, keep in mind that a simple robot who does 1-2 tasks very well is better than a complex bot struggling at doing everything! :ahh:
We always favor roller style ball pickups. The great advantage is not having to time the pickup with the presence of a ball. You can just run the roller, and when they drive up to it, it’s automatically picked up. It makes ball acquisition much faster.
Sounds like a solid strategy. We were rookie all stars at the Wisconsin Regional and at Worlds last year and all that I have to say is with a strategy like that make sure you get in as much driver practice as possible! With the extra time left (due to simple design) begin preparing all of your scouting as well as practice putting up your pit area and do mock judge interviews, because the judges are in charge of the Rookie All Star award. If you have any other questions feel free to PM me.
Our concern for a roller style is height. We’re hoping to be able to do the low bar, and feel that with the height of the ball + roller + limits on extrusion from the bot, we’d not fit.
The diameter of the ball is 10", and if you’re using a roller you’re going to want to compress the ball slightly to make intake easier… say 1". That means the bottom of your roller is 9" off the ground, so the top of whatever apparatus you use could easily be under the 14" aperture of the low bar.
If you have a wheeled intake then you should be able to get low goal pretty easily. If you have a skilled driver (practice practice practice) then you have an excellent shot at doing really well.
Looks like it might be time to work on a wheeled intake! We’ll have to tweak our chassis size, but it appears doable.
With a wheeled intake, do you think we’d need to pull the ball 100% ‘in’ to a holding area kind of thing, or would pulling saying 4 inches of the ball and compressing it to hold it be sufficent? I’m looking at perimeter issues, potentially.
If I was in your position I’d try to have at least some form of solo scoring potential - such as a reversible roller intake for low goal scoring. A lot of teams won’t want to worry about getting out of their comfort zone if they pick you. Many successful teams will have their own plan for the whole 2:30, and might not want a robot that requires them to go out of their way and potentially mess up their cycles.
I’ll pile on…pincers mostly push the ball away from you, while rollers suck it in. But you might want to play with the ball, and make a bumper, and see how the ball behaves when you drive into it, on carpet, with a bumper, at different heights. You don’t really need a running robot to do this, you can fake it with some cleverness, some pieces of wood, and a student pretending he/she is the robot. Having a bumper will also help if you are working on designing a roller mechanism, because the ball pickup thingy will likely involve the bumper in it’s design.
If you can deliver the ball to the low goal, you can also deliver it to an alliance partner. Design for both, and you can either help your partners, or score on your own.
Traversing defenses and hanging can give you quite a bit of solo scoring potential.
I feel like having 67’s approach of the 2012 game (balancing game with shooting basketballs instead of shooting basketballs with an end game) may be a great way to approach this year’s game.
I’ve never done an intake with top and bottom rolles, but a ramp should work just fine, adding rollers just seems to adds complexity. Just make sure the ramp won’t get caught on the defenses. Also a good tip with intakes is to throw power at it until if you touch the ball, you own it.
Two rollers take more work to build than one roller…
Also, might want to check the bumper rules carefully, again.
And think about how you will line up on the ball…do you want the robot to need to be aimed precisely to get a ball? or do you want to get a ball easily, without having to be exactly in line with it? The ball acquisition might be happening on the other side of the field, where the driver can’t see so well.
Both a top/bottom roller design, and a top roller+ramp design are viable solutions. We actually had a surprising level of success with side rollers as well – take a look at Greenhorns Ri3D for an example of this.
Whatever you go with, prototype it! Make sure that your proposed geometry actually engages with the ball the way you expect it to. A little testing goes a long way.