#robotics Logs

Sep 21 2014

08:26 anonnumberanon it will have intersting stuff on it thats why i want it to have a cheap and robust mobile base
09:10 ace4016 if you're looking for cheap, why did you pick treads?
09:11 ace4016 they're expensive, take a lot of energy to move, and they're slow. great for rough terrain though. rugged wheels might be a better bet. but i don't know your intended area of operation
10:30 rue_house cooler
13:07 Cheekio Why would you be driving around a cooler
13:07 Cheekio I guess if it's full of beers and ice, maybe some sandwich meats, yeah, treads would be best
13:08 Cheekio it's not a long distance though, I'd honestly think a couple of cartesian linear actuators mounted to the sides would be your best bet
13:25 MrCurious superglue fingerssssssssssssssssssssfoc
13:42 Hyratel1 anonnumberanon, how big of a robot?
13:42 Hyratel1 anonnumberanon, https://dl.dropboxusercontent.com/u/33593534/images/Robot/DSCN2011-1k2.jpg
13:42 Hyratel1 this is a $600 robot
13:57 MrCurious why did we get into robotics? was it because restoring classic cars was not expensive enough?
13:58 MrCurious Hyratel1: lookss nicely made
14:56 MrCurious https://www.sparkfun.com/products/13024?utm_source=SparkFun+Customer+Newsletter&utm_campaign=c540763953-Sept15-19&utm_medium=email&utm_term=0_fa5287abaf-c540763953-60595073
14:56 MrCurious cant decide if it is tempting, or just another toy
15:04 MrCurious so dual core atom @500mhz vs quad core arm at 2ghz
15:04 MrCurious yeah, color me not sold on it
15:08 MrCurious heh, this wins one INTERNET for any arduino fans out there... http://uecide.org/tour
16:32 rue_mohr2 I had a working linear error amp
17:08 Cheekio So what kind of power can you get out of small solenoids?
17:09 Tom_itx small power
17:10 Cheekio I guess you really are just pitting an electromagnet against metal across a gap
17:34 anonnumberanon robot should not be too big it should have probably 20 to 30 square centimeters on top of it to be able to mount a pair of these http://www.robotshop.com/en/sharp-gp2y0a710k0f-ir-range-sensor.html
17:34 anonnumberanon and probably a somewhat sophisticated arm
17:35 anonnumberanon as well as a charging circuit and maybe a small solar panel if i determine it was large enough to charge the robot in one full day. otherwise no point
17:36 anonnumberanon i was thinking of threads because of maybe being better at navigation with a 3d map that the robot creates around itself as it goes.
17:43 anonnumberanon Also I am considering that sensor I linked above 360 degrees but I don't know how fast the sample rate is . hopefully fast enough for quick 360 rotation. in which case the sample getter rotator will be a unit in itself and charge itself only when not rotating and will send the sample data by wifi to the brain of the robot. The robot may or may not be able to drive slowly while collecting its environments 3d data.
17:45 GargantuaSauce you did note that its minimum range is a metre right?
17:45 GargantuaSauce that may make it unsuitable for small robot navigation
17:46 GargantuaSauce and if you look at the timing diagram on the datasheet you'll see that the sample time is 16.5+-3.7ms
17:47 GargantuaSauce so like 50hz
17:47 GargantuaSauce pretty slow
17:52 MrCurious anonnumberanon: you may need an array of 4 or 6 of them
17:52 MrCurious so you divide the area and increase the #urveys per minute
17:52 MrCurious # of surveys
17:55 anonnumberanon gargantuasauce. this was why i wanted a pair. of this sensor coupled with one that does up to a meter
17:56 GargantuaSauce i see
17:56 anonnumberanon nice find mrcurious i looked for that rate in the data sheet and could not find it.
17:57 MrCurious that was GargantuaSauce's find...
17:57 MrCurious i just stated the mockingly obvious divide and conquor
18:07 anonnumberanon i have two choices so far, either a sucky toy tank modified into a robot or the white tank base that is on Robotshop right now.
18:07 GargantuaSauce use 2 wheels and a caster
18:21 anonnumberanon whats a caster. servo-controlled?
18:23 GargantuaSauce a caster like you'd see on the front of a shopping cart
18:23 GargantuaSauce spins and rotates freely
18:23 anonnumberanon ah yes
18:24 anonnumberanon may not be stable enough for robot arm operation
18:24 GargantuaSauce so use two
18:27 GargantuaSauce treads are pretty hard to work with i think
18:28 anonnumberanon i reckon this would simplify the driving chassis so we can focus more on the payload
18:30 anonnumberanon or should i say the payloads
18:31 anonnumberanon i recently gave up on Lidar in favor of IR sensors for 3d mapping. Am I chasing unicorns? Lidar is expensive as all the gold mines in the Universe.
18:31 GargantuaSauce technically that is also lidar
18:32 GargantuaSauce but yes spinny turnkey lidar sensors are pretty expensive
18:34 anonnumberanon I'm hoping to make something a little like this, except mine won't fly https://www.youtube.com/watch?v=Mz5z_xaB9i8
18:35 anonnumberanon unless using a 5-meter telescoping arm I don't think I could map a room as well.
18:35 anonnumberanon unless I tilted the sensor and compensated with math, in order to get the same result
18:36 GargantuaSauce you arent going to get a map that isn't garbage without a good sensor
18:38 GargantuaSauce so if a primary goal of the project is making a good map, you're probably going to need to get spendy
18:38 GargantuaSauce or spend a very significant amount of time building a good sensor from scratch
18:44 anonnumberanon Primary goal: making a map so that the robot knows where it is, doesn't drive in the walls, while it inspects the walls for electrical outlets to recognize them and see if any are taken or free to use.
18:44 anonnumberanon That's the main mission.
18:45 GargantuaSauce how are you looking for outlet
18:45 GargantuaSauce s
18:45 GargantuaSauce vision?
18:45 GargantuaSauce vision will do much better SLAM than crappy ir sensors
18:45 anonnumberanon I don't know yet I was thinking of first making a map of the walls, then driving parallel to each wall with camera pointed at the wall and using robot vision/image recognition to find outlets.
18:47 anonnumberanon okay im reading the wiki for SLAM then, for some reason I was thinking video would not be a great idea but maybe it is.
18:47 GargantuaSauce it will be quite computationally expensive
18:47 GargantuaSauce (but will in any case really)
18:49 anonnumberanon Like with a required link to maybe a laptop nearby?
18:50 GargantuaSauce you could probably fit something suitably high-end onboard
18:52 anonnumberanon impressive https://www.youtube.com/watch?v=_-p08o_oTO4
18:54 GargantuaSauce yeah
19:19 orlock Hmmm
19:20 orlock I set up basic wireless comms using a FS1000A but i only get noise if i mose the transmitter and receiver into different rooms
19:54 anonnumberanon does a 1000 maH battery takes one hour to charge from a 1 Amp charger?
19:55 anonnumberanon I'm looking at solar panels for my robot
19:56 anonnumberanon any thoughts on this? http://www.ebay.com/itm/10W-DIY-Solar-panel-kit-52-38mm-solar-cell-tabbing-wire-bus-wire-flux-pen-/261600355152?pt=LH_DefaultDomain_0&hash=item3ce898a350
19:58 GargantuaSauce seriously doubt it's worth it
19:59 tWorthCr4p declines to
19:59 GargantuaSauce your username says it all
19:59 anonnumberanon Tell that to Opportunity rover.
19:59 anonnumberanon and all satellites ever, etc
20:00 NotWorthCr4p why would i tell them anything?
20:00 anonnumberanon Although lol, I'm looking for something only about 10 square centimeters.
20:00 GargantuaSauce opportunity drives at an average of <1cm/s
20:00 anonnumberanon heh
20:01 anonnumberanon i think opportunity is stuck isn't it?
20:01 anonnumberanon forgot which one got one bad wheel and a panel was covered with sand too much to charge anything
20:01 tWorthCr4p
20:01 GargantuaSauce that's spirit
20:03 GargantuaSauce also isnt your intent to use this indoors anyway?
20:04 GargantuaSauce mapping outdoors will be notably more difficult
20:05 anonnumberanon no i was thinking of making it look for a window and just stay at the window and charge whenever it had nothing to do
20:05 anonnumberanon don't know if silly idea or not
20:06 GargantuaSauce just make a charging station for that
20:06 GargantuaSauce it'll actually be effective
20:06 tWorthCr4p
20:07 anonnumberanon Yeah like the Roomba.
20:41 rue_mohr2 yardba?