#robotics Logs

Mar 18 2015

02:28 Hyratel get an inverse kinematics library
02:29 rue_house make one, its fun
02:31 solarjoe4 thanks! that was the right keyword
16:50 veinofstars what does the happy hour entail?
18:07 Hyratel Fritzing, why do you have fixed-size bendpoint handles
18:09 deshipu Hyratel: bendpoint handles?
18:09 deshipu Hyratel: you would prefer if the size was changing according to some cool animation? ;)
18:09 Hyratel the drag points for segment ends
18:10 Hyratel I would rather it scale based on the trace width, or by a control button in-UI
18:10 deshipu I learned that using the 'move to bottom' option often help to not select something you don't want
18:11 deshipu but yeah, it's a mess
18:11 deshipu I can't really think of a workable solution, though
18:11 Hyratel MTT/MTB doesn't help when two bendpoints of the same trace are so close together it's a cointoss which you grab
18:12 deshipu I like how Inkscape does it -- the handles are always the same size on the screen, no matter how much you zoom
18:12 Hyratel ooh nice
18:12 deshipu so if you zoom enough, they become small relative to the image
18:12 Hyratel idea
18:12 Hyratel EDA plugin for inkscape
18:12 Hyratel port Ftzg to an inkscape plugin
18:13 deshipu Hyratel: have you tried reporting a bug in Fritzing? maybe they will fix it
18:13 Hyratel not yet. I'm ears-deep in a project
18:13 deshipu it's a commercial startup, so they might actually do work :)
18:15 deshipu bah, it's c++
18:15 deshipu shame
18:15 deshipu if it was python, I could try to do it
19:01 bindigoat grand plans https://indymedia.org.au/2014/06/21/australian-association-of-radiation-mitigation-professionals
19:06 deshipu considering that homo sapien has some 7 million years so far, planning for 500 million ahead seems a little of an overkilll
21:59 sector_0 anyone here have experience with SCARAs?
22:02 sector_0 how do you trace a straight line?
22:02 sector_0 do you take it in discrete steps?
22:08 Triffid_Hunter sector_0: most reprap firmwares simply segment the line down to 0.5mm lengths or so, where the nonlinearity becomes fairly invisible.. I'm sure it's possible to do the math in actuator space too
22:09 Triffid_Hunter doing it in realtime on a microcontroller may be another matter, depending on how fast you plan to move
22:16 sector_0 Triffid_Hunter, I see
22:35 sector_0 Triffid_Hunter, what about velocity though?
22:36 sector_0 how do such systems handle the how linear velocity of each rotation?
22:37 Triffid_Hunter sector_0: smoothie checks velocity in actuator space and caps cartesian space velocity to avoid exceeding limits
22:59 rue_house ok I really need to work out this balance formula
22:59 rue_house same formula, two radically different applications
23:00 rue_house a) two counteracting air muscles
23:00 rue_house control position and the overall tension between the two
23:00 rue_house b) the mowerbot, tractor drive
23:00 rue_house control the direction, and the velocity
23:01 rue_house two factors in, two factors, out, matrix in between
23:04 rue_house if I call the inputs A and B, and the outputs X and Y
23:04 zhanx Balance a weight on it
23:04 rue_house then X=f(A,B)
23:04 rue_house and Y = f(A,b)
23:05 zhanx Look up tav
23:05 rue_house see? this is easy
23:05 zhanx Table
23:05 rue_house hmm
23:06 rue_house all I have to do is define f (and I should have called the other one g)
23:06 rue_house X = f(A,B)
23:06 rue_house Y = g(A,b)
23:07 rue_house damn chift
23:07 rue_house arg I cnt type
23:07 rue_house hkschklhklgvdrgvhnikadgvhkdgv
23:07 zhanx Quick brown fox jumps over the lazy dog
23:07 rue_house it would be less effort to smash the keyboard with my head and the result is the sane
23:08 rue_house a quick jump over the lazy brown dog
23:08 zhanx Use pen and paper helps me
23:08 rue_house plan what I'm gonna type?
23:08 rue_house then schedule it
23:08 zhanx Oh ughhh
23:08 rue_house break it down into achivable goals?
23:09 zhanx Yes
23:09 zhanx And a function table is easy
23:09 rue_house <the commitee is out, please stand by for typing activity>
23:10 zhanx Really know points in a circle or 3d you can't do?
23:10 rue_house I dont know how the fuction works yet, for some reason I cant wrap my head around it
23:10 rue_house zhanx, ?
23:10 rue_house X = f(A,B)
23:10 zhanx Did that stop me?
23:10 rue_house Y = g(A,B)
23:11 rue_house all I need to do is define f and g
23:11 rue_house this is more progress than I'v made in months
23:11 rue_house so, lets focus
23:11 zhanx X=f (0,1) nope next
23:11 rue_house motors...
23:11 rue_house I need a blank sheet of paper
23:12 rue_house ugh, I have to clear out the sheets of paper under the keyboard, its getting tipsy
23:14 zhanx When I thought I invented slam did math stop me?
23:14 zhanx Nope just figured out what someone did
23:15 rue_house I have a queue of things to think about
23:16 rue_house like, focus on
23:16 rue_house lets take the tractor drive robot as the example
23:16 rue_house A = robots speed
23:16 rue_house B = delta between wheels speeds
23:17 rue_house A = sum of wheel speeds
23:17 zhanx Rue over thinks again
23:17 rue_house average?
23:17 rue_house sure
23:17 rue_house A = average wheel speed
23:18 rue_house B = delta of wheel speeds
23:18 rue_house X = right motor speed
23:18 rue_house Y = left motor speed
23:18 zhanx Pid
23:18 rue_house ok, see, I'm defining the problem
23:18 zhanx Done
23:19 rue_house A = (X+Y)/2
23:19 rue_house B = X-Y
23:19 rue_house so, now I just have to isolate for X and Y
23:20 rue_house rammstein alpha
23:20 rue_house wolfenstein alpha
23:20 rue_house damnit
23:20 rue_house whats it called
23:21 zhanx Math?
23:22 zhanx Exarctpolation
23:22 rue_house I know this sounds stupid, please ask me the name of a site that will solve formulas
23:23 zhanx Google
23:23 rue_house no please just ask me
23:23 rue_house its a brain interlock problem
23:23 zhanx Ok what site
23:23 rue_house no you have to ask me the whole question
23:24 anx grows a beard while wai
23:24 zhanx What is the name of the site that solves formulas?
23:24 rue_house no I cant communicate with the part of my brain that has the answer, I have to read you asking
23:25 zhanx I asked
23:25 rue_house damnit, I was sure that would work
23:28 rue_house wolfram alpha
23:29 rue_house :)
23:29 rue_house X=2A+B-x
23:29 rue_house Y=2A-x
23:29 rue_house all I had to do was enter A=(x+Y)/2 , B=X-Y
23:30 rue_house oh I messed up again
23:30 rue_house ok
23:31 rue_house X = A+(B/2), Y=A-(B/2)
23:32 rue_house seems pretty simple
23:32 rue_house lets make a simulator
23:32 rue_house #include <stdio.h>
23:33 rue_house int main(void) {
23:41 zhanx Int gotobed = 1;
23:41 rue_house 9:21 I have 24 minutes left
23:42 rue_house damnit, that took me a min to work out
23:42 zhanx If gotobed <= 1 then
23:43 Hyratel woahkay, Eagle is REALLY confusing
23:47 rue_house in what way?
23:47 rue_house you didn't try to use the autorouter did you?
23:47 rue_house I talked to a 30ya pro, he said even on the top end software autorouters suck
23:48 rue_house zhanx, you know whats funny, I'v come up with this formula before
23:48 rue_house ... for taking a joystick and operating a tractor drive robot
23:49 rue_house THESE ARE _MY_ FOOTPRINTS!
23:49 Hyratel rue_house, just the basic interface. it's such a drastic difference than what I'm used to it's throwing me for a loop
23:49 zhanx Or darn
23:49 e_house lifts his head and looks around at the large ci
23:49 zhanx Very very large
23:50 zhanx FYI rue my forge is almost done
23:50 rue_house forge or smelter?
23:51 zhanx After that wax cast . Forge not smelter we had this talk
23:51 zhanx Bug man hammer etc
23:51 zhanx Autocorrect sucks
23:51 rue_house hehehehehe
23:52 rue_house can take back iraq, easy
23:52 Hyratel rue_house, the text-command driven interface is probably what's tripping me up the most
23:52 rue_house can defeat auto spell check.... dont ask...
23:52 zhanx I could
23:52 rue_house Hyratel, text!?
23:52 Hyratel wire[enter], move[enter]
23:52 Hyratel instead of hotkey driven
23:52 rue_house dude, you turn off the took buttons?
23:53 rue_house tool
23:53 rue_house sorry, I'v lost the ability to type
23:53 Hyratel and I keep hitting [space] to try and drop down to 'basic select mode' like in sketchup
23:53 zhanx Yeo
23:53 Hyratel no
23:53 zhanx Same here
23:54 rue_house ok, speed = 5, delta = 0; X: 5.000000, Y: 5.000000
23:54 rue_house so that works
23:54 Hyratel I like using keyboard shortcuts where I can but with text commands instead of hotkeys, it's throwing off my deeply worn habits
23:54 rue_house speed = 5, delta = 5; X: 7.500000, Y: 2.500000
23:54 rue_house :)
23:54 rue_house Hyratel, its all mouse driven
23:54 zhanx Linear
23:55 rue_house push the keyboard aside
23:55 zhanx Look up table
23:55 rue_house Hyratel, left button is enter, right button is escape
23:55 rue_house or... is that... librecad
23:55 Hyratel faster to type out 'wire' than to hunt for the wire toolbar button
23:55 rue_house zhanx, it'll work better as forumulas
23:55 rue_house Hyratel, its the line
23:56 rue_house !?!?!
23:56 rue_house you just click on it
23:56 zhanx Eeprom is fine
23:56 rue_house zhanx, Picasos brush dude, Pacasos brush.
23:57 Hyratel rue_house, in all programs with the option I set large toolbar buttons. I have suck eyes, it seriously takes longer for me to visually parse out the toolbar from a comfortable sitting position than it does to type "wire[enter]'
23:58 rue_house then how do you know where to click to put the wire?
23:58 Hyratel but it does bug me that there's no base level 'select'
23:59 Hyratel with the mouse?
23:59 rue_house but you cant see the end of the wire
23:59 Hyratel I can parse the scheme view fine.
23:59 Hyratel it's nicely high contrast
23:59 rue_house and you cant see the toolbar icons on the left?
23:59 rue_house all you humans are deaf and blind, geez