Hypothetical Situation - Stairs

[pandamonium]

some people interpret the game hint Little Eva - locomotion - Robotic Locomotion http://en.wikipedia.org/wiki/Robot_locomotion

The point of this is not to discus the game hint, there are 500 other posts about that. This is a fun mental exercise that can challenge us for the next week.

I assume that for the sake of rookies the kit drive-train would have to be able to play the game so perhaps a bonus obstacle close to the driver station such as the ramp in 06.

So here is my Hypothetical Situation:

4 steps each 6 inches high, spaced 6 inches apart. At the top of the stairs there is a platform 2 feet tall, 3 feet wide, 8 feet long. At the end of the match each robot on the platform scores 50 points.

don't actually build a robot just describe you strategy and how you would attempt to mechanically solve this challenge.

[apalrd]

Look at robots from 2004. They climbed steps very well.

A couple of highlights:
our robot (33):
The entire top piece (the big refrigerator-box) moved by window motors, and had wheels on the front. It would tip back, and get the wheels onto the platform, then move down (lifting the robot, but the back two wheels remained on the ground). Then it would drive up. Almost all of the weight of the robot was in the chassis (it was full weight, 130lbs with battery, and the entire top piece weighed around 10lbs), so it wouldn't tip over easily.

Simbotics (1114): They had four wheel pods (two crab pods and two casters) each with a pneumatic piston. They would lift all of the pistons, then run into the platform. Sensors on each pod would lift it as it hit the platform.

[pandamonium]

that was a different challenge. The steps I was thinking of are much larger than 04, but similar concepts should work

[akoscielski3]

Just in case there are stairs this year, would it be best to have tracks or what ever they are call ed, like on tanks. ??? unlesss we have to use legs i mean. and Where can i find some or purhase them???

[Chris is me]

Originally Posted by akoscielski3

Just in case there are stairs this year, would it be best to have tracks or what ever they are call ed, like on tanks. ??? unlesss we have to use legs i mean. and Where can i find some or purhase them???

You shouldn't be buying*, building, or designing anything to be used on your final robot before Kickoff.

*with the probable exception of tools, supplies, raw materials, etc.

[BrendanB]

Originally Posted by Chris is me

You shouldn't be buying*, building, or designing anything before Kickoff.

*with the probable exception of tools, supplies, raw materials, etc.

Why not? I would love to be prototyping a tank drive in the off-season even though it is almost over. Off-season is THE time for prototyping new ideas or mechanisms you are unfamiliar with so come build season you have knowledge that you can build off of.

[Chris is me]

Originally Posted by BrendanB

Why not? I would love to be prototyping a tank drive in the off-season even though it is almost over. Off-season is THE time for prototyping new ideas or mechanisms you are unfamiliar with so come build season you have knowledge that you can build off of.

Edited my post to clarify.

[alicen]

what about something like:
http://www.youtube.com/watch?v=a0NFrA-Nx4Y
prototyping that kind of drive train would even be useful for that fabled water game

also, for those wanting a real challenge, try this method:
http://www.youtube.com/watch?v=kpfjnqaFwtU&NR=1

[Dave Scheck]

I know this doesn't address the OP's original question, but to add on to what was said here

Originally Posted by apalrd

Simbotics (1114): They had four wheel pods (two crab pods and two casters) each with a pneumatic piston. They would lift all of the pistons, then run into the platform. Sensors on each pod would lift it as it hit the platform.

We had a similar solution, except it was just front and back instead of 4 independent modules like they did. We had 8 light sensors that we used to detect where the robot was relative to the platform and raised/lowered the modules accordingly. It worked great, but in practice the time that it took to raise the modules wasn't as fast as we had hoped (the goal was to be able to drive on without slowing down)

Check out our Encore promo video from that year to see more details.

Again, that was a different challenge with only a single step to deal with.

[BrendanB]

As a mentor of one of those rookie teams who will most likely be using the kit frame unless CADed otherwise, I would recommend designs such as 190's 2004 robot. Or I would really like to try 1276's off-season prototype.

190: http://www.youtube.com/watch?v=Q5nnGGRi-94

1276: http://www.chiefdelphi.com/media/photos/35982

[Teched3]

If I remember the game correctly, WPI (Team 190) had a great platform climber, went around a goal obstruction, and hung on a bar, all autonomously. Can't wait to see the new game. Speculation is generally fruitless, but can be fun for some.

[EricH]

Originally Posted by Teched3

If I remember the game correctly, WPI (Team 190) had a great platform climber, went around a goal obstruction, and hung on a bar, all autonomously.

They went up the 2" stairs, and intentionally built narrow to go around the goal. I remember that part of their robot was a piece of laminated paper to reach over a line and "straddle" it so they'd be in position for the stairs.

I might try 330's approach: oversized rear pneumatic tires (12") with an angled front and 6" wheels to lead up the step.

Tank tracks: Outback Manufacturing has a kit for those, but most teams make their own with varying degrees of success (the Triplets in 2006) and unsuccess (any robot that throws more than one or two in a season). They'll work for stairs, but I wouldn't recommend them for flat floors necessarily.

[Karthik]

Originally Posted by apalrd

Look at robots from 2004. They climbed steps very well.

Simbotics (1114): They had four wheel pods (two crab pods and two casters) each with a pneumatic piston. They would lift all of the pistons, then run into the platform. Sensors on each pod would lift it as it hit the platform.

Originally Posted by EricH

Tank tracks: Outback Manufacturing has a kit for those, but most teams make their own with varying degrees of success (the Triplets in 2006) and unsuccess (any robot that throws more than one or two in a season). They'll work for stairs, but I wouldn't recommend them for flat floors necessarily.

Although we were relatively successful with both the complex wheel pods of Simbot Simon in 2004 and the tank treads of Simbot Beckham in 2006, neither solution was chosen for pure climbing ability.

In 2004, the reason we went with with the independent lifting wheel pods was because we felt it was the best way to climb a 6" step, while using a swerve drive. If we weren't already committed to swerve drive, there's no way we would have gone down this road. This was just way too complex of a solution for a problem that could be handled in a much more conventional way.

In 2006, our use of tank treads had very little to do with climbing the ramps that were on the field. We went with the treads because we felt we could get more traction by taking advantage of the longer contact patch between the tread and the carpet. Granted, this does seem a bit odd considering the equation for traction has no surface area component. When you're dealing with two surfaces that interlock in the way carpet and roughtop tread do, the traditional model for evaluating traction doesn't exactly apply. Regardless, we chose treads because we wanted that robot to be immovable, the benefit of climbing the ramp was an added bonus. Again, the complexity, maintenance and cost could not have been justified just for climbing when a much simpler solution could have sufficed.

So, I don't have any groundbreaking suggestions for innovative stair climbing devices. However, I can say this: If you are going to go with a complex design like the ones discussed above, you better make sure the extreme design costs are justified by the game benefits. Typically the best way to justify these costs for a function is to make sure you get multiple points of utility out of them.

(And if you didn't bother reading all of that, here's the synopsis: Keep it simple!)

[davidthefat]

http://www.societyofrobots.com/robot_asme.shtml
Now, depending on the rules, this kind of robot might be possible. As long as the 3 inch rule is not in this year's rules, it should work great.
http://www.societyofrobots.com/robot...t_monkey.shtml
Now I am not sure if this is possible with the bumpers in the way, but his has honorary mentions.

Try this:
http://www.youtube.com/watch?v=67CUudkjEG4

[Hawiian Cadder]

if i was on a rookie team the way that i would do this is an 8wd with the 10 inch kit wheels. the middle two being drop center and rubber traction, the back one being a slick wheel, and the front being a 10 inch IFI wheel, i think the IFI wheel would hold up better with impacts and has a higher traction coefficient. 10 kit wheels will not fit in the 38 inches that we are given but if they are layed out like this:

XXXXXXXX.......................XXXXXXXXXX
..........XXXXXXXX.XXXXXXXXXXX


with the chain in between the two rows of wheels, then it would work.