RFC on battlebot idea

Post #33,999 by drewk 4/1/02 12:24:28 PM Reply	RFC on battlebot idea I've got an idea for a battlebot and was hoping people with expertise in real-time motion control could comment on the feasibility. The basic idea is a spinbot (one where the entire bot spins) but one that can be driven. Most of the spinbots are a body, two wheels, and an arm or flail sticking out one side. The bot can be driven normally, but its main attack is to spin in place at high speed. Devastating attack, but the opponent merely has to not drive into it. My idea is to add some sensors that will enable the bot to orient on a fixed point, and lights on the top that strobe in sync with the rotation, so the driver can identify the orientation the bot is fixed on. Then, to drive the bot in a particular direction one of the drive wheels would be slowed slightly, also in time with the rotation. It seems possible that careful manipulation of differential rates on each side would allow controlled movement. (Most likely slow, but movement.) Does this sould reasonable to anyone who actually works with high-speed motor control? === I can't be a Democrat because I like to spend the money I make. I can't be a Republican because I like to spend the money I make on drugs and whores.
Post #34,000 by Silverlock 4/1/02 12:36:29 PM Reply	No clue. Sounds very tough though. I've been wondering for a while now, why no projectiles? I can understand not allowing a remote controlled rifle but what about something like a sticky net or bicycle chain. Another thought I've had is still a little unformed but goes like this; bot uses conventional wheels/tracks, but has the ability to "jump". A pistion arrangement of some kind could accomplish this and the body of the bot could then be the offensive weapon (enough jumps should give a good chance to land on the opponent at some time). The best scale for an experimental design is ten millimeters to the centimeter.
Post #34,003 by drewk 4/1/02 12:43:43 PM Reply	Problem with jumping Some of the flip-bots (Toro in particular) are claimed to be able to toss 500 lbs. several feet in the air. The only way to produce the same damage to your opponent would be to drop your own bot on it from that height, which would cause as much damage to yourself -- on each jump -- as to the opponenet, should you be lucky enough to come down on him. === I can't be a Democrat because I like to spend the money I make. I can't be a Republican because I like to spend the money I make on drugs and whores.
Post #34,010 by drewk 4/1/02 1:18:06 PM Reply	I put an image up It's [link\|http://twiki.iwethey.org/twiki/bin/view/Test/SpinBot\|here]. === I can't be a Democrat because I like to spend the money I make. I can't be a Republican because I like to spend the money I make on drugs and whores.
Post #34,018 by pwhysall 4/1/02 2:16:57 PM 4/1/02 2:18:19 PM Reply	Re: RFC on battlebot idea Hrm. Based on what I've seen of spinning weapons and bots in Robot Wars here in the UK, it's basically a Bad Idea. Here's why. First up, to make a truly effective spinny thing, you need a powerful motor that's got enough torque to not stop the second it hits something - and you need to put enough battery in the bot to power it. Secondly, control is a massive issue - even when everything's perfect, these things are bastards to drive. If you brought your design to the UK, a flipping robot like [link\|http://www.robotmayhem.com/vip/s4robots.php?id=1001\|Chaos II] (which has high speed, a very powerful flipper and excellent driveability - and a truly gifted driver) or a crusher like [link\|http://www.robotmayhem.com/vip/s4robots.php?id=1575\|Razer] (hugely powerful crushing arm - something like 9000KG of pressure) would basically trash it fairly quickly. I've been watching RW since season one and successful bots have key characteristics: 1. They can either drive upside down or have a SRiMech (Self Righting Mechanism). Or, like Behemoth, just weigh lots and be hard to tip. 2. They don't have complex weapons. Flippers and axes are the best - although the [link\|http://www.robotmayhem.com/vip/s4robots.php?id=1508\|Hypnodisc] bot has a 6000RPM spinning disc and is notable as the only successful robot with a weapon of this type. 3. Traction, traction, traction. You've gotta be able to push the enemy around. 4. Durability is worth more than anything - [link\|http://www.robotmayhem.com/vip/s4robots.php?id=1494\|Behemoth] has basically no weapons and no speed, but it's got huge traction and is basically indestructible. 5. Ground clearance is critical - you need to be low enough to make it difficult for a flipper to chuck you around, but high enough that you don't get caught at funny angles against obstructions, unable to get a wheel to the ground. 6. Speed is cool, but coupled with a dodgy control system it's a recipe for disaster. There have only been a couple of successful, fast bots. 7. Control. All the successful bots seem to be easy and predictable to drive, and their R/C systems are reliable. Check out [link\|http://www.robotwars.co.uk\|The UK Robot wars web site]. Warning - looks like a sack of shite in Galeon, but is functional. Needs Java for an irritating little scroller app in the top left corner. Peter Shill For Hire [link\|http://www.kuro5hin.org\|There is no K5 Cabal] Edited by pwhysall April 1, 2002, 02:18:19 PM EST Expand All History
Post #34,021 by drewk 4/1/02 2:35:03 PM Reply	Different goal Robot wars involves navigating a course. The American [link\|http://www.battlebots.com/\|BattleBots] is head-to-head combat. The biggest difference though IMO is that some of the American bots cost over $20,000 to build. [link\|http://www.battlebots.com/meet_the_robots/meet_robot_specs.asp?id=26\|Biohazard] comes to mind. And things like [link\|http://www.battlebots.com/meet_the_robots/meet_robot_specs.asp?id=617\|Son of Whyachi] have weapons that can take apart reinforced concrete without flinching. In this setup, manuverability takes a back seat to offensive power. All hail the knockout hit. === I can't be a Democrat because I like to spend the money I make. I can't be a Republican because I like to spend the money I make on drugs and whores.
Post #34,704 by tseliot 4/8/02 10:51:20 AM Reply	Designing to win isn't everything, though. For example, we took Rocky Bot Boa to RW:EW, and although it did quite well (except for a questionable judges' decision), it was basically just a big brick of C-channel. It beat every bot out there, but there's not a single builder (or producer) I know who would say "what a cool robot". There was some open animosity against the builder of Rocky for Not Being Creative. One of the most annoying things about building these days is it's getting so boring. We're down to wedges and spinners, and the tech heads of BB and RW (and Robotica, and BotBash, and ...) are doing everything in their power to change that. Go ahead and build your jumper, your spinner (IIRC Mauler 5150 drove this way, you're not alone), your creative masses yearning to breathe free. Just do it on a show with an appearance fee (eg RW:EW), not a contest prize (eg BB). --------------------------------- A stupid despot may constrain his slaves with iron chains; but a true politician binds them even more strongly by the chain of their own ideas;...despair and time eat away the bonds of iron and steel, but they are powerless against the habitual union of ideas, they can only tighten it still more; and on the soft fibres of the brain is founded the unshakable base of the soundest of Empires." Jacques Servan, 1767
Post #34,706 by drewk 4/8/02 11:22:30 AM Reply	If we're going for cool ... My favorite is still [link\|http://stage.onlyagame.org/photogallery/battlebots/images/photo3.jpg\|Mechadon]. Best looking bot yet, but completely unsuitable to combat. === I can't be a Democrat because I like to spend the money I make. I can't be a Republican because I like to spend the money I make on drugs and whores.
Post #34,765 by tseliot 4/8/02 4:20:50 PM Reply	Man, that thing was heavy Trey kinda fudged the weight limits for that one, just because it was So Cool. IIRC it was 425 lbs? We picked it up on the way to BB2K in San Fran; they had to drive it out on a forklift...sharp corners and all that. I don't think it was completely unsuited to combat--remember the Big Fight it had with Trey's Ginsu? The only reason Mark lost that fight was he couldn't get the thing righted when it got knocked on its butt first time. And the only reason he couldn't do that was he had added a steel plate horizontally on the butt minutes before the fight: it made a perfect tripod out of his bot. Cryin shame, it was. Ginsu pretty much destroyed himself wanging on Mechadon. P.S. Look for Mark Setrakian's day-job work in the upcoming MIB II. --------------------------------- A stupid despot may constrain his slaves with iron chains; but a true politician binds them even more strongly by the chain of their own ideas;...despair and time eat away the bonds of iron and steel, but they are powerless against the habitual union of ideas, they can only tighten it still more; and on the soft fibres of the brain is founded the unshakable base of the soundest of Empires." Jacques Servan, 1767
Post #34,019 by marlowe 4/1/02 2:21:27 PM Reply	It seems to me... It looks like there's only two drive wheels on this thing. It seems to me it can only move laterally - and simultaneously spin - when the wheels happen to be oriented in nearly the direction of the desired movement. So the thing will move in jerks, two per complete rotation, and it won't get far with each jerk. And it'll be spinning during each jerk, so I see in my mind's eye something like a crabwalking motion. Now if you're willing to stop spinning while you move laterally, and if you use bidirectional motors, then you have a hope of getting it somewhere in a reasonable amount of time. And a turning radius of zero. [link\|http://www.angelfire.com/ca3/marlowe/index.html\|http://www.angelfir...e/index.html] Truth is that which is the case. Accept no substitutes. If competence is considered "hubris" then may I and my country always be as "arrogant" as we can possibly manage.
Post #34,022 by drewk 4/1/02 2:39:44 PM Reply	"Reasonable" is in the eye of the beholder I wouldn't expect it to move much with each revolution. But some of these bots are claimed to spin at several hundred RPM. Given that, even if it could only go a fraction of an inch per revolution, that adds up quickly. And compared to some of the stomp-bots, might still be a fairly steady movement. === I can't be a Democrat because I like to spend the money I make. I can't be a Republican because I like to spend the money I make on drugs and whores.
Post #34,033 by boxley 4/1/02 3:20:46 PM Reply	change the tires to globes that way you could crab a little easier thanx, bill TAM ARIS QUAM ARMIPOTENS
Post #34,065 by marlowe 4/1/02 6:37:36 PM Reply	Just so long as you move faster than... whatever it is you're chasing. [link\|http://www.angelfire.com/ca3/marlowe/index.html\|http://www.angelfir...e/index.html] Truth is that which is the case. Accept no substitutes. If competence is considered "hubris" then may I and my country always be as "arrogant" as we can possibly manage.
Post #34,127 by drewk 4/2/02 8:51:36 AM Reply	Not with how it's scored You have to actually attack your opponent. You can't run away the whole time. Kind of like boxing, actually. You don't have to try particularly hard to go on the offensive, but you can't just avoid him the whole time. The problem most spin bots have is that they can pursue or they can use their main attack, they can't do both. Opponenets learn to just stay out of range until they stop spinning and try to move, then come in. === I can't be a Democrat because I like to spend the money I make. I can't be a Republican because I like to spend the money I make on drugs and whores.
Post #34,131 by Silverlock 4/2/02 9:00:53 AM Reply	Could this work? It wouldn't be speedy by any means but, .... Have the power for the spinning flail/hammer/pick separate from the drive motor. Some kind of turret mechanism for the rotating rod of greatness. As for the drive, not even have a motor, have a brake that is only applied in pulses timed with the rotation of the weapon to take advantage of centrifigul force. The best scale for an experimental design is ten millimeters to the centimeter.
Post #34,138 by drewk 4/2/02 9:57:00 AM Reply	Basically what I'm thinking The turret idea has been done quite a few times. The best example is probably [link\|http://www.battlebots.com/meet_the_robots/meet_robot_specs.asp?id=85\|Ziggo]. Most of the spinners have a frame that drives like a typical bot, with a spinning turret mounted on top. This means that the inertia of the weapon is only what you have in the turret. The other type of spinner is seen in [link\|http://www.battlebots.com/meet_the_robots/meet_robot_specs.asp?id=337\|Carnage Raptor], where the entire bot spins, putting the most inertia to work for the weapon. The problem these bots have is lack of maneuverability. I'm trying to get the massive inertia of a fully-spinning bot, but have at least enough maneuverability to be able to attack. "Pulsed brake" is a pretty good way of describing what I came up with. === I can't be a Democrat because I like to spend the money I make. I can't be a Republican because I like to spend the money I make on drugs and whores.
Post #34,185 by a6l6e6x 4/2/02 2:50:28 PM Reply	And the LRPD sayeth "Slices, dices, chops..". :) Alex "Never express yourself more clearly than you think." -- Neils Bohr (1885-1962)
Post #35,894 by Steven A S 4/18/02 1:19:10 PM Reply	Seems to me that this type of motion would prevent you from reaching the inertia you are looking to obtain with this plan. You will be constantly speeding and slowing the drive on each wheel for "forward motion", and the jarring effect when the wheels are perpendicular to your line of motion would slow it further. The best way seems to be like they did with Ziggo with two separate motive units (spinning and locomotion). It's just a matter of weighting the spinning part to get the momentum you're looking for. Besides too much complexity just increases the potential for critical failure. ~~~)-Steven---- "I want you to remember that no bastard ever won a war by dying for his country. He won it by making the other poor dumb bastard die for his country..." General George S. Patton
Post #35,902 by drewk 4/18/02 1:46:12 PM Reply	But mechanical complexity would be lower Ziggo has a frame that includes locomotion, and a spinning turret for a weapon. My design would have basically two moving parts: the drive motors[1]. How fast could it actually move? Let's suppose it spins 600 rpm. If, on each revolution, you could slow one wheel just enough, in a narrowly controlled portion of its rotation, to give a differential of about 1/4-inch in the distance the two wheels travel, that would give you about 1/8-inch worth of lateral motion, or 1 1/4 inches per second. Not fast, but certainly enough to pursue an opponent who didn't want to attack while you are at speed. I still don't have any idea if there are electric motors that can do this kind of speed, and still have fine enough or fast enough control to do the pulsed braking. [1] The simplist construction would be to have the wheels attached directly to the shafts, but the potential for un-fixable damage would be unacceptable. So the motor shafts would obviously use gears to drive the axles. A few more moving parts, but then there would be something to fix if an axle gets bent. === I can't be a Democrat because I like to spend the money I make. I can't be a Republican because I like to spend the money I make on drugs and whores.

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