Re: Legged Robots
 

Or some weird robot with a wheel based drive system but also with legs on the outside. That would be so awesome.

Re: Legged Robots
 

im pretty sure team 71's beast robot in 2002 was a hybrid of the two, with wheels to speed up to the goals then the one way super legs crawl it to the end zone with all three goals.

innovation, legged robot, world champion

Re: Legged Robots
 

another advantage of legs would be if the terrain was incredibly bad a legged bot like this would be really slick

http://www.youtube.com/watch?v=wIuRVr8z_WE

now thats maneuverability

Danny B

Re: Legged Robots
 

It's a very cool idea, but there's a lot of reasons no to.
Bumpers have to be 10-15 inches off the ground, and they can't be moving. You only have so many motors to power everything.
Legged robots would have a problem with balls going into their frame perimeter.
Legged robots would probably be slower.
Obviously, as 71 showed, there are games here legged robots are masterful and great. However, this game just isn't the one for it.

Re: Legged Robots
 

Our team (1648) looked at walking robots last year. It seemed a perfect application on the slick regolith surface. We would have used the slick wheels as feet, and even did a very interesting prototype with a VEX kit. The VEX version walked very well on the slick surface and pulled a trailer with no trouble. It walked well, with enough speed, and could turn easily. The video we shot looks like a big insect plodding along.

As said above, we had to throw it all out because of the bumpers. They can't move up and down and have to stay inside the bumper zone. Otherwise, we would have had a really neat walking robot.

Sometimes, it seems, the rule makers want conformity rather than innovation. Either that or it's the Law of Unintended Consequences butting in.

Dr. Bob

Re: Legged Robots
 

Does anybody have a video of 71 that year? I would love to see it!

Re: Legged Robots
 

Re: Legged Robots
 

my $.02

what happens to your robot's legs when a 6WD comes over and rams the bolts out of you? :eek:

of course, i'm thinking of the legs being fairly long rather than thick logs that don't have much of a vertical component.

I'd love to see legged robots in FIRST, but i don't see it happening unless there is a "double" terrain, where legged robots can go, but if your robot has only wheels it might not be able to traverse that area.

Re: Legged Robots
 

You bring that up, so I will ask this, will the wheel's torque go up if you use multiple motors to power the same wheel?

Re: Legged Robots
 

Being somewhat interested in FIRST history as well as legged robots, i can think of 2 off the top of my head:ahh:

71 from 2002
and 190 from '01. The mechanism was retractable and was scrapped fairly early in the competition season.
See picture here

Re: Legged Robots
 

For those who are interested in 71, here are a couple more videos to check out:

http://www.youtube.com/watch?v=h4slv...eature=related
(Just a match with some really nice close-ups)

http://www.youtube.com/watch?v=lAmAnkYDUQM
(A pretty incredible pushing match between 71 and 60, another goal-grabbing robot)

Re: Legged Robots
 

Legs aren't practical.

In battlebots they give a 100% weight bonus* for walking, and it still isn't worth it. :(

However, they are awesome, and I'm all for cool stuff.

The main problem is that we don't have enough powerful motors in the kit to make an effective omni-directional walking machine. Which means, that instead of "legs" what we really need to build are linkages (which can turn with regular tank style steering).

I've tossed around a mechanical spider linkage DT, but have never gotten around to designing it.

Why build it? Because you'd be famous instantly! Everyone at champs would come and see it!

If my team had more machining skills I'd gladly sacrifice winning for fame :D



*I've suggested FIRST adopt the same bonus in the "design the game threads"

Re: Legged Robots
 

Well, some of the most successful robots in Battlebots history (namely one of the first Son Of Whyachi variants) were walkers. Then they changed the definition of a "walker" to make building one that could work too impractical for the weight.

I guess I don't see the point in doing something "cool" like legs, when wheels appear to be ideal solutions for pretty much any robotics game there ever will be.

Re: Legged Robots
 

It's a pretty cool concept, legged robots can move pretty quickly. I still think wheels could move faster in the FIRST robotics world because it's a concept that we have developed and been working with for some time now. Just my two cents.

Cass

Re: Legged Robots
 

The Klann linkage is good if you need to climb-over things such as steep inclines like this year, or vertical walls, like '04, however it doesn't provide the most stable platform and you would have to be careful to make sure the oscillations don't move your bumpers out of the bumper zone.

A Jansen mechanism would keep the platform much more level, if engineered properly, and uses the same number of legs and motors as Klann. Also, slopes aren't a huge deal for them either, the mechanism was originally used for kinetic sculptures that ran on beaches, which are sloped, While Jansen mechanisms may not be able to take on this years bumps, I believe the ramps from '03 would be fine with the proper foot design.