#robotics Logs

Jun 18 2015

00:39 Jak_o_Shadows I have a friend who has
00:40 Jak_o_Shadows haven't gotten around to it personaly
00:40 MrCurious got neato lidar working with it last night and rendering in rviz
00:40 MrCurious so far, the experience is it is rather slick
00:40 Jak_o_Shadows cool
02:14 firefish5000 Good day. I am looking to get into robotics. Anyone have sites/tutorials/software (preferably linux based) you would recommend for a beginner(I know basic C/C++/Perl/lua/Bash... programming, but nothing of robotics).
02:17 firefish5000 Sugestions for simulators would also be apreatiated. I am currently tryning to figure out gazebo.
02:30 deshipu f3lp: letsmakerobots.com
02:31 deshipu f3lp: sorry
02:31 deshipu firefish5000: ^^
02:32 f3lp deshipu, still, I'll check it out. thanks!
03:27 firefish5000 Thanks deshipu! Reading their tutorial now.
04:16 wolfmanjm deshipu: is the axis system fo reach leg the same? or would left and right legs be inverted signs in y? eg moving +y on left would move the leg out away from body, would the right leg with a +Y move move in toward the body or away from it?
04:17 wolfmanjm ie is it a mirrored move or identical with respect to the body coordinate system?
04:19 deshipu wolfmanjm: they are inverted
04:20 deshipu wolfmanjm: there are the xdir and ydir arrays that control it
04:20 wolfmanjm so +y move will move both away from the body
04:20 deshipu yes
04:20 deshipu I decided that was easier
04:20 wolfmanjm yea so at a higher level you take that into consideration using the xdir and ydir
04:21 wolfmanjm yes it is easier each leg stands alone and behaves the same regardless of where it is on the body...
04:22 deshipu well, for x I made it the other way around
04:22 wolfmanjm I prefer that as well. Just wasn't sure if it was doing that.
04:22 wolfmanjm so for front legs +x moves the leg forward? but back legs do the opposite?
04:23 deshipu yes, so if you move all legs by the same amount, they all move the same direction
04:23 deshipu in parallel
04:24 wolfmanjm so +x would move all legs forward
04:24 wolfmanjm or towards the front
04:24 deshipu I don't remember which sign is forward, but yeah
04:24 wolfmanjm ok
04:25 deshipu now I realize how arbitrary it is
04:25 deshipu but at the time it seemed obvious
04:25 wolfmanjm wait if you move all legs by the same X, Y they do not all move in the same direction if what you said before was correct
04:26 wolfmanjm the left legs will move in the opposite diretion in Y to the righ tlegs
04:26 wolfmanjm the X will move in the same direction
04:26 deshipu yes
04:26 wolfmanjm ok
04:26 wolfmanjm that seems the most intuitive approach I think
04:27 wolfmanjm I wrote a openGL based leg simulator, It seems to do the correct thing when hooked up to the IK, but the coordinate systems and angles are all different :)
04:27 wolfmanjm different to a real physical leg that is
04:28 wolfmanjm but I still having something wrong on the physical bot as the legs do not quite move as they should, probably a combination of signs is wrong
04:33 deshipu it may be also that the frequency ranges for your servos are different
10:44 SpeedEvil http://www.ebay.co.uk/itm/25KG-Medium-Glass-Grit-Blast-for-Abrasive-Shot-Sand-Blasting-Cleaning-metal-wood-/251653486794?pt=LH_DefaultDomain_3&hash=item3a97b778ca
10:44 eedEvil ponders a robot to sort crushed g
11:07 deshipu SpeedEvil: a set of sieves would be faster
11:07 SpeedEvil By colour.
11:08 veverak https://scontent-vie1-1.xx.fbcdn.net/hphotos-xpt1/v/t35.0-12/11639527_1028195077191877_1175594891_o.jpg?oh=f9cd4a8ddfa1c31268969fb9dfe48868&oe=5584F160
11:08 veverak finally!
11:08 veverak home made nozzles :)
11:09 deshipu SpeedEvil: just get some of them color sieves ;)
11:09 deshipu veverak: gas stove nozzles?
11:09 SpeedEvil deshipu: I hear south africa still has some NOS
11:13 veverak "gas stove" ?
11:15 deshipu veverak: you know, for cooking
11:16 veverak noooh
11:16 veverak 3d printing
11:16 veverak e3d nozzle
11:16 veverak they publish all they drawings online
18:19 HelloShitty Hello
18:19 HelloShitty Anyone around?
22:16 MrCurious neato lidar connected to odroid-c1(arm) -> wifi -> i3 running rviz working
22:16 MrCurious ros is quite nice