#robotics Logs

Jun 29 2012

00:24 furrywolf heyas
00:25 Keknom What sort of robotics projects do most people here do?
00:26 furrywolf I haven't done much with robotics lately. came in here for help with hydraulic pump design. :)
00:27 Keknom oh, sadly I can't offer much aid in that area
00:28 Keknom I mostly just do battlebots
00:29 furrywolf rue_* has a lawnmowerbot or three, I think... very similar... :P
00:30 Keknom What weight?
00:30 furrywolf no clue.
00:31 Keknom ah, here is a picture of one of my team's bots http://i43.servimg.com/u/f43/14/83/37/32/678a0210.jpg
00:31 furrywolf bah, all my flights changed from UAL to SKW.
00:31 furrywolf build a blendo clone.
00:32 Keknom Full body spinners tend to be a bit to hard to do in my opinion, none of them can run upside down
00:33 furrywolf use wheels with d > h...
00:33 Keknom wheels on the top can't really work if top shell is spinning
00:34 furrywolf heh. I always figured I'd make everything spin, including the motors, then use a gyro and fast electronics to add cyclic speed control to the wheels, so it goes a specific direction.
00:34 Keknom There is a type of battlebot which only has one motor, and one wheel that has the whole robot spin
00:35 Keknom and moves by pulsing the motor
00:37 furrywolf nah, I'd have four wheels, probably two drive wheels and two casters. spin them opposite directions, whole robot spins. when the gyro decides it's pointing the way you want to go (add some indicator lights on the outside of the housing so you know what it's thinking), the wheels spin faster in that direction (one speeds up, one slows down). when at right angles to the desired direction, same but opposite speeds. etc.
00:37 Keknom With that though woul dhave to sacrifice armor weight for wheels and such
00:38 furrywolf ah, but _everything_, batteries, motors, etc, is spinning mass.
00:38 furrywolf not just a shell.
00:38 Keknom Still is best to have htick armor though
00:38 furrywolf also, I don't see how this is any more sacrafice for drivetrain than any other robot.
00:40 Keknom true, but I've also just never seen a 4 wheel drive robot spin well.
00:40 furrywolf it would be two wheel drive, with the drive wheels in the center, and little casters at the ends.
00:41 Keknom oh now I get it , I thought it would be 4 wheel drive
00:42 furrywolf -=- style, casters at the ends, drive wheels in the middle.
00:43 orlok furrywolf: thats the setup of mine
00:43 furrywolf and a nice fast gyroscope, near-direct-drive motors, fast speed controller, and a bit of processing power.
00:43 Keknom brushless or brushed drive motors?
00:43 orlok i used drill motors
00:44 Keknom ah, mine does too
00:44 Keknom here is current design I have
00:44 orlok fuck, i havent touched that thing in ages
00:44 Keknom http://i.imgur.com/z8Lj0.png
00:46 rrywolf is far more interested in constructive rather than destructive devices, so has never built
00:48 Keknom Suppose that is a better mindset.., team I'm, on did roughly 30k+ in property damage this year
00:50 furrywolf you did twice as much damage as my annual gross income.
00:51 Keknom Hurray for destruction!
01:00 furrywolf that money could have done something useful...
01:05 furrywolf three-five people could have lived for an entire year off the money you cost people.
01:15 yahweh_ so you awake rue?
01:39 furrywolf "Status Taxiing (pushed from gate 36 minutes ago)" grrrrr...
01:57 furrywolf grrr. united says the plane is still on the ground, flightaware thinks it's halfway here. each has about a 50% chance of being right.
01:58 orlok shroedingers plane?
02:04 furrywolf and now united's status page won't load.
02:04 furrywolf grrr
02:04 furrywolf bbl, got to head to the airport, even if it means sitting around for hours.
03:23 rrywolf flops onto katsmeow-afk for bed
03:46 tsmeow-afk
04:49 Sunnyday Morning everyone
08:50 rue_more maybe it didn't land and is on the ground
08:52 katsmeow-afk they drove in on the groundfrom Chicago
08:52 Tom_itx what?
08:53 katsmeow-afk the thing that didn't fly
08:54 katsmeow-afk Tom:
08:54 katsmeow-afk [01:47] <furrywolf> grrr. united says the plane is still on the ground, flightaware thinks it's halfway here. each has about a 50% chance of being right.
08:54 katsmeow-afk [01:48] <orlok> shroedingers plane?
08:55 rizlah lol
08:55 rue_more http://www.flickr.com/photos/geekphysical/sets/72157630104134554/with/7176685337/
08:56 rue_more hah taxied the whole way
10:08 swb o/
10:14 swb anyone here specialise in evolutionary robotics?
10:30 joink swb: you mean kids in school nowadays? :P
10:31 swb haha joink
10:40 Sunnyday Do you mean genetic algorithms that design their own robots? I had a lesson about it 10 years ago, this one legged robot that acomputer designed and worked
10:42 Sunnyday Does the autopilot make use of your better acceleration?
10:42 Sunnyday Or is it like Frontier where if you have a heavy ship its crap?
10:46 swb Sunnyday, yeah evol algorithms that evolve parameters to nerual netowrk controllers for robots
10:46 swb but in simulation
10:52 Sunnyday I know of many algorithms that do that, there's the old neural network threshold function middle layer perceptron
10:52 Sunnyday There's the heuristic tree algorithm
10:53 Sunnyday There's the hibernian learning tree
10:53 Sunnyday There's good old fashioned Runge-kutta
10:53 swb thats for learning the nn tho
10:54 swb like during the interaction with the environement
10:54 swb this evolves the weights instead, they are static when it is being evaluated
10:55 Sunnyday Sum of each neurons weights times their byasses times the input and if its above the threshold output one else output zero
10:55 Sunnyday and each epoch the weights change the bias does not
10:57 swb Yeah doing it this way the weights don't change each epoch, amazingly it seems to work
11:18 Sunnyday So if your weights remain static and the bias remains static, how is it able to learn? Surely something in the system MUST change every epoch
11:27 katsmeow-afk HP / Hewlett-Packard 54600A 100 MHz Oscilloscope ; 7 bids $46.00+$15.00 shipping Time left: 3h 47m ; http://www.ebay.com/itm/380449234548
11:30 swb Sunnyday, only the inputs change with the epoch, thats what I'm saying it doesnt "learn" in the conventional way
11:30 swb its only feed back with the environement is through the fitness function
11:31 swb and then more fit individuals are bred in a GA style
11:50 Sunnyday So you alter the input data each epoch NOT the weights? Hmm curious
11:51 swb well it alters the input data, in that its dicated by the robots current interaction with the environment
11:51 swb I evolve the weights after a full run of epochs and it has been evaluated
11:59 Sunnyday Won't the input data get corrupted then?
11:59 Sunnyday Its a robot that says, I don't want to learn, I'll change the book instead so it's something I already know
11:59 swb nah not really, its doesnt change the problem
12:00 swb it has some control over its inputs, cause it is able tointeract with the environment, but the problem remains the problem, and its solution to it is evaluted by the fitness function
12:00 swb which does not change...
12:01 Sunnyday This is very new they didn't teach this when I was at Uni
12:01 Sunnyday Must be something developed in the last 10 years
12:01 swb yeah I think so, its a fairly new field, not that well established
12:01 swb but I find it fascinating that you can do that, essentially use a simulation to evolve weights for a NN encoded as a genome to solve dynamic problems
16:33 katsmeow-afk mouser just beats this price at qty 100 , http://www.ebay.com/itm/260551792231 , but them mouser adds a minimum $8 to ship it , effectively doubling the cost to buy http://www.ebay.com/itm/260551792231 from a usa distributor
21:26 rue_more http://hackaday.com/2012/06/29/self-balancer-does-it-differently-than-were-used-to-seeing/
21:26 rue_more huh
21:31 Tom_itx so the question is... if those 2 wires don't go there, where the heck do they go?
21:35 rue_more http://hackaday.com/2012/06/29/self-balancer-does-it-differently-than-were-used-to-seeing/
21:35 rue_more cool
22:30 Tom_itx ok they do go there but why isn't the other two working?
22:32 Tom_itx this is irritating
22:46 rue_more that was close
22:46 rue_more road block comming back from groceries
22:46 rue_more they stopped 3 cars infront of me, pulled one over, wavedme thru
22:47 rue_more :S
22:50 furrywolf I turn around and find another route. roadblocks are, at least in the US, unconstitutional, but that doesn't seem to stop cops any.
22:53 rue_shop "I need to mow the lawn" "ok..." "...so please move the 12' robot?" "oh! right, k, got it"
22:58 Tom_itx what were they checking for?
22:58 rue_shop well, I have my play pants on, so they must be looking for respectable like people
23:01 Tom_itx i'm too tired to do this
23:02 Tom_itx it's gotta be a software thing, but it was working before
23:02 Tom_itx and everything else works