#robotics | Logs for 2016-06-05

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[02:01:41] <rue_shop3> 3 tracks reprogrammed
[02:31:13] <RifRaf> 300mm of rain yesterday, still flooded in :)
[02:32:54] <rue_shop3> save it up to put out the fires later
[02:35:07] <RifRaf> not enough containers, tank was full after first 20mm
[02:39:27] <rue_shop3> is that 20mm^3/m^2?
[02:39:39] <rue_shop3> casue the units dont add up for me
[02:40:53] <RifRaf> hrm, the tank collects from a large area, ie the roof, and was nearly full already
[02:41:22] <RifRaf> so the other 400mm has just run off, only had 100mm today
[02:42:52] <RifRaf> rue are you doing any computer vision stuff?, like roborealm, i just invested in it hopeing i can make some smarter robots
[02:43:32] <rue_shop3> I'v never done and dont plan on any computer vision
[02:43:42] <RifRaf> is old but still seems to be actively updated, and has support for alot of motor control
[02:43:46] <rue_shop3> less the AR stuff I might play with one day
[02:45:04] <RifRaf> using a smart phone
[02:45:30] <RifRaf> didn't think you would have a smart phone till at least 2030 :)
[02:46:49] <RifRaf> btw, still coming to canadia, but is sold out again this year, maybe next year
[02:49:54] <rue_shop3> heh
[02:50:04] <rue_shop3> I got a smartphone and a tablet
[03:27:36] <rue_shop3> ok, the marbelator works agian
[03:33:06] <RifRaf> whats it do?
[05:59:21] <Jak_o_Shadows> well, the first test of toothpaste as electro-eth electrolyte dont look too promising
[05:59:28] <Jak_o_Shadows> will try on a longer sample overnight
[07:52:07] <goppo> with accelerometers, could the acceleration values alone be converted to pitch angle?
[08:45:45] <deshipu> goppo: yes, provided the sensor doesn't accelerate while you take the measurements
[08:46:18] <deshipu> goppo: then you simple get the gravity, and can easily calculate pitch from that
[08:46:23] <deshipu> simply*
[08:51:09] <RebelCoder> Guys, do you think, satellite engineering/programming is part of Robotics ?
[08:51:23] <RebelCoder> Like cube/nano satellite ?
[09:03:15] <SpeedEvil> Tehre is a big overlap between a computer and a robot
[09:03:25] <SpeedEvil> a satellite can have no moving parts.
[09:03:32] <SpeedEvil> This doesn't mean it's not a robot
[09:08:19] <RebelCoder> Robotics for me is Hardware + Software + A.I.
[09:08:47] <RebelCoder> So, let's say a Moon Rover is as much of a Robot as a Moon satellite is ?
[09:08:51] <RebelCoder> Do you agree ?
[09:08:54] <RebelCoder> Just wondering...
[09:12:00] <ace4016> nope
[09:13:22] <deshipu> you can call any device a "robot", depending on how you define it
[09:13:52] <deshipu> since there is no one definition that everyone agrees with
[09:16:10] <deshipu> but people building sattelites usually face different challenges than people building, say, industrial robots
[09:31:14] <pokmo> with just two gyros, how is it sufficient to level a copter?
[09:31:15] <pokmo> http://43oh.com/2010/11/msp430-based-quadcopter-ez430-rf2500/
[09:31:28] <pokmo> you can't get the pitch angle with just gyro, right?
[09:39:03] <deshipu> you can keep track of the changes
[09:39:22] <deshipu> but you will have some drift
[09:42:01] <pokmo> deshipu, so without accel, one could determine pitch with just gyro?
[09:42:14] <pokmo> all of the formula that i've found use accel to compute pitch
[09:42:22] <pokmo> like pitch = 180 * arctan (accelerationX/sqrt(accelerationY*accelerationY + accelerationZ*accelerationZ))/PI
[09:42:53] <deshipu> pokmo: the gyro tells you the rate of change of pitch
[09:43:25] <deshipu> pokmo: if you know the initial pitch, and keep track of the change, you can calculate the current pitch with some accuracy
[09:43:33] <deshipu> pokmo: but any errors will accumulate
[09:43:41] <pokmo> yeah
[09:43:54] <pokmo> feels like they'd stack up fast
[09:44:52] <deshipu> depends on how good your sensors and your code are
[09:48:21] <pokmo> deshipu, typically, do budget copters fusion accel with gyro for levelling?
[09:48:28] <pokmo> or do they just make do with gyro
[09:49:30] <deshipu> the ones I know do fusion, but you would get better answers at channels/forums dedicated to rc models and/or quadcopters
[09:50:56] <pokmo> deshipu: ok thanks
[09:59:07] <pokmo> i wonder why so many homemade copters are made using Wii Motion Plus gyro
[10:00:10] <deshipu> possibly it's cheap and easy to get, due to the popularity of Wii
[10:00:29] <pokmo> why not just gyro ICs
[10:00:33] <pokmo> there're heaps out there
[11:21:11] <rue_bed> one day I need to make an air-table for playing with some flight stuff
[11:21:48] <rue_bed> or do a hovercraft with a RC motor
[11:21:51] <rue_bed> hmmm
[11:33:30] <rue_shop3> my projects keep needing servos with the ability to read positon and control torque
[11:33:44] <rue_shop3> think I'm gonna have to come up with a mod for hobby servos if I want to keep using them
[11:43:18] <ace4016> or make your own servos from scratch
[11:46:00] <rue_shop3> well, yea, but you have to say something for the nice small bundled pacage that hobby servos come in
[11:46:14] <rue_shop3> then again, but to say you cant just break out the motor and pot
[11:46:46] <rue_shop3> use a 6 pin connector with a key
[11:48:09] <rue_shop3> been dieing to use up all the channels of a TLC5940 pwm genorator
[11:48:20] <rue_shop3> at worst thats 8 servos
[11:49:02] <rue_shop3> maybe I could think out the lookup-table PID servo controller I thought up a while back
[11:49:23] <rue_shop3> PID in ~4 cycles
[11:49:56] <rue_shop3> and the best part is that its not limited to linear responce
[11:50:19] <rue_shop3> the P factor can be exponential if you need it to be
[11:50:57] <rue_shop3> (doing the servo loop for that solenoid was interesting that way)
[11:51:26] <rue_shop3> ok, I have one robot arm ready for the faire, I have 2 or 3 more to set up
[11:51:36] <rue_shop3> I'm THINKING of making them dance
[11:51:43] <rue_shop3> casue the position control just dosn't matter
[11:52:34] <rue_shop3> I could burn off 2 in a dance routine
[11:54:04] <rue_shop3> the whole reason I built these arms with hobby servos was so they would be fast enough to dance
[13:01:03] <rue_shop3> hmm need good robot dancing music....
[16:53:47] <rue_shop3> anyone alive?
[16:54:02] <rue_shop3> I need suggestions for music to make my robot arms dance to
[16:54:55] <SpeedEvil> Well, there are the obvious.
[16:55:04] <SpeedEvil> We are the robots - Kraftwerk
[16:55:40] <SpeedEvil> Goldie' Lookin' Chain - half man - half machine
[16:56:04] <[VEGETA]> rue_shop3: nothing is better that the legendary "Cha la head cha la!"
[16:56:07] <rue_shop3> kraftwerk...
[16:56:15] <rue_shop3> rings a bel...
[16:56:33] <rue_shop3> hmmm
[16:56:48] <SpeedEvil> Or you could go all out. Have it play an instrument
[16:56:57] <rue_shop3> I dont have time
[16:57:00] <SpeedEvil> Have it be an instrument.
[16:57:20] <SpeedEvil> Have resonant elements in the arms construction and it bangs against the surroundings making music
[16:57:49] <rue_shop3> these could do bells
[16:58:10] * SpeedEvil imagines a bell juggling robot.
[16:58:26] <SpeedEvil> Doing polyphony with timeslicing at five bells a second.
[16:59:20] <SpeedEvil> Imagine hard and soft hands - if you juggle it one way it makes a noise.
[17:01:24] <rue_shop3> rattle :) see how long cheap hobby servos hold up
[17:02:50] <rue_shop3> SpeedEvil, Die Mensch-Maschine ?
[17:03:02] <rue_shop3> its nin spek deutch...
[17:03:07] <rue_shop3> ist..
[17:18:33] * SpeedEvil listens to Kraftwerk.
[17:29:58] <rue_shop3> so what I'm gonna need to do it mod my catpure program to save realtime data somehow
[17:32:11] <SpeedEvil> Or transcode from midi
[17:32:19] <rue_shop3> I dont have time
[17:32:29] <rue_shop3> I have about 12 hours elft
[17:32:38] <rue_shop3> to finish getting everything ready
[17:43:32] <rue_shop3> ok, my software sucks for realtime capture
[18:30:16] <rue_shop3> stepDelay = 30000;
[18:30:23] <rue_shop3> usleep(stepDelay);
[18:30:37] <rue_shop3> so
[18:30:50] <rue_shop3> max sample speed is
[18:31:00] <rue_shop3> .03 seconds?
[18:31:20] <rue_shop3> axies.motionSteps = time / 30000;
[18:31:38] <rue_shop3> and if I specify less than 2 steps, it dosn't send the positions
[18:31:53] <rue_shop3> so I have .06 sec min slices
[18:31:59] <rue_shop3> 0.020166, 12.220787, 45.250000, 19.344009, 16.014000, 17.712008, 29.381985
[18:31:59] <rue_shop3> 0.040240, 11.456987, 43.750000, 14.992008, 22.952999, 17.712008, 29.381985
[18:31:59] <rue_shop3> 0.020177, 10.947787, 43.250000, 12.688008, 27.065001, 17.712008, 29.381985
[18:31:59] <rue_shop3> 0.040236, 9.929387, 43.250000, 3.984008, 38.373001, 19.248007, 29.637985
[18:31:59] <rue_shop3> 0.020155, 9.420187, 43.750000, 1.424008, 42.228001, 20.272007, 30.149984
[18:32:06] <rue_shop3> but the data runs a bit faster than that
[18:32:31] <rue_shop3> if I bring up the step delay, there is too much update data and the serial port saturates
[18:33:02] <rue_shop3> hmmmm
[18:33:24] <rue_shop3> min is about .02 sec, I need a min of .06
[18:33:33] <rue_shop3> so if I delay .04 sec, I'll be ok
[18:38:36] <rue_shop3> ok, but the delay is making my program not keep up with the keybaord buffer...
[18:42:19] <rue_shop3> ok thats pretty close
[18:42:29] <rue_shop3> its got bugs, show me software that dons't
[18:43:02] <rue_shop3> its a dance, its not to specific music and its tempo is terrible
[18:43:10] <rue_shop3> but thats a dance
[18:47:43] <rue_house> hahahah
[18:48:02] <rue_house> if I make a cute little set of headphones for it, i dont ahve to worry about actually playing music
[18:48:10] <rue_house> HAHA! I love it!
[21:22:03] <Anniepoo> Music from Metropolis would work, I think. the (human) actors in it often were imitating robots
[21:24:09] <rue_shop3> the thought occured that if I play music, I'm going to have to listen to the song for 2 days straight, so I put some headphones on it and gave it a little itunes nano
[21:24:14] <rue_shop3> we dont need to hear it
[21:51:25] <rue_house> almost... there...
[21:52:01] <rue_house> https://youtu.be/slxOrCXxXOg
[21:59:24] <orlock> heh cute
[22:00:17] <orlock> i've been cadd'ing up a sumo bot
[22:00:55] <rue_house> you ever gonna build it?
[22:01:17] <orlock> yeah, i have until Sep 23rd
[22:01:24] <orlock> and i've built things!
[22:01:32] <rue_house> you better stop cadding and get building then
[22:02:01] <rue_house> I got arm8 doing the marbelator, arm 9 can dance
[22:02:10] <rue_house> arm 7 can show off realtime control
[22:02:18] <rue_house> and then for arm4
[22:02:24] <orlock> the building should just be a matter of exporting the stl files of the parts that dont yet exist into slic3r
[22:02:29] <orlock> and sending to the printer
[22:02:38] <rue_house> what to do with arm4, its stepper, so its gonna be a channange to get going
[22:02:56] <orlock> 3kg weight limit
[22:02:57] <rue_house> orlock, then correcting, reprinting, and refitting
[22:03:01] <rue_house> then again
[22:03:23] <orlock> i was looking at an 8 wheeled bot, 2 on each corner with gear drives and 2 motors
[22:03:34] <orlock> do-able, but i'd be cutting it very close on weight, and it would be top heavy
[22:03:55] <orlock> so i've gone for 4 wheels, 2 left and 2 right - basically half the 8 wheeled bot
[22:04:10] <orlock> rue_house: thats what all the CAD is for!
[22:04:24] <orlock> so i dont need to reprint/refit so much
[22:04:36] <orlock> i measured up the motors and wheels
[22:05:19] <orlock> now i have them all in place i just need to cad up the housing to hold everything together
[22:05:36] <rue_house> half the first reprint is to correct for print size differences
[22:05:40] <edgardosilvi> Hi ... someone I can reference a page of educational robotics? Working with boys 14 to 17 years. Thank you
[22:05:51] <edgardosilvi> In Arduino
[22:06:22] <orlock> rue_house: i know i have a static .05mm excess in X and Y
[22:07:06] <orlock> i can compensate in cad
[22:07:40] <rue_shop3> edgardosilvi, hmm
[22:07:59] <rue_shop3> you want to just buy something and program it?
[22:08:05] <rue_shop3> boebot?
[22:08:12] <rue_shop3> w/arduino
[22:08:32] <edgardosilvi> only program
[22:09:25] <edgardosilvi> implement exercises and challenges students
[22:09:35] <rue_shop3> hmm
[22:32:52] <rue_shop3> its rs232, its got no gripper controller, and there is no working zeroing routine for the steppers
[22:37:18] <edgardosilvi> ok
[23:27:00] <rue_shop3> oh....
[23:27:03] <rue_shop3> ohhhhhhh...
[23:27:10] <rue_shop3> I wrote a library for the stepper motor arm
[23:28:04] <rue_shop3> :S it uses version 1 of the interpolator....
[23:28:17] <rue_shop3> I'm at version 3...
[23:29:33] <rue_shop3> hmm
[23:29:44] <rue_shop3> hmmmmm
[23:31:36] <rue_shop3> ah, there was a fork
[23:32:08] <rue_shop3> after the stepper arm, I made new libraries that worked completely differently for the hobby servo arms
[23:32:22] <rue_shop3> and NOW it seems I want to merge the two branches....
[23:35:05] <rue_shop3> now, my libary is supposed to be able to group up to 65000 axies of anything(s) and move them all togethor as if they were one device...
[23:35:48] <rue_shop3> you know, it seems that seeing if the old code works would be a good start
[23:36:51] <rue_shop3> and it uses version 2 of my linux serial library
[23:40:50] <rue_shop3> wow, it still compiles
[23:41:03] <rue_shop3> that shows how good I am with my library compatability
[23:41:25] <rue_shop3> A D
[23:41:34] <rue_shop3> how do I get from there, to there....
[23:41:47] <rue_shop3> I see a detour thru M and Q in my future
[23:42:48] <rue_shop3> Tom_itx, does zlog do any chat stats other than the logging?
[23:55:49] <rue_shop3> hey, its talking!
[23:55:52] <rue_shop3> sweet!