#robotics Logs
Jul 11 2017
#robotics Calendar
12:08 AM rue_shop3: :) and has a shiney metal ass?
12:32 AM rue_shop3: zhanx, what can I do with 4.0uC of Am241?
12:34 AM rue_shop3: how many smoke alarms do I need to put in the trashcan for it to go into runaway?
12:36 AM rue_shop3: circle -d .825
12:36 AM rue_shop3: Radius is : 0.412500
12:36 AM rue_shop3: Diameter is: 0.825000
12:36 AM rue_shop3: Circumfrence is : 2.591814
12:36 AM rue_shop3: Area is : 0.534562
12:36 AM rue_shop3: hmmm so the peizo has about .5"^2 area
12:37 AM rue_shop3: I wonder how much force to push it off the silicone its mounted with
12:37 AM rue_shop3: pressure sensor?
12:37 AM rue_shop3: hmmmm
12:37 AM anonnumberanon: just ordered motor battery esc propeller for this RC plane I'll be flying in a few weeks
12:37 AM anonnumberanon: gotta convert it cause it had a glowplug engine
12:37 AM rue_shop3: heh, the electric movement
12:38 AM anonnumberanon: feelsexciting
12:38 AM rue_shop3: so WHATS wrong with a glowplug engine?
12:38 AM anonnumberanon: the gas motor is broken and they're really expensive
12:38 AM rue_shop3: EEEEEEEEEEEEEEEEEEEEEEEEEEEEeeeeeeeeeeeeeeEEEEEEEEEEEEEEEEEEEeeeeeeeeeeeeeeEEEEEEEEEEEEEEEEEEEEEEEE
12:38 AM rue_shop3: broken?
12:38 AM rue_shop3: broken!?
12:38 AM rue_shop3: stepped on or you just cant get it running?
12:39 AM anonnumberanon: yeah with my cuz we tried to run it like 2 summers in a row, impossible to find a replacement also in France unless paying like 175 euros or something
12:39 AM anonnumberanon: can't get it to run
12:39 AM rue_shop3: no you can probably fix it
12:39 AM rue_shop3: its most likey something simple
12:39 AM rue_shop3: like a plugged hole
12:39 AM anonnumberanon: it's about 30 years old i think
12:39 AM rue_shop3: dosn't matter
12:39 AM anonnumberanon: yeah ill tear it down but i want to spend all my time actually flying the thing
12:39 AM rue_shop3: heh
12:40 AM rue_shop3: I'm amazed at the things people throw out that just need a simple fix and nobody knows how or cares
12:40 AM anonnumberanon: maybe i will crash it the first go
12:40 AM anonnumberanon: last plane, i crashed it
12:40 AM anonnumberanon: then i practiced a lot on this computer simulation with a real remote connected to the computer
12:41 AM anonnumberanon: but that was 16 years ago lol
12:41 AM anonnumberanon: i remember: make it go around you in circles before going crazy on throttle and controls
12:41 AM rue_shop3: I'v not paid for a lawnmower yet
12:41 AM rue_shop3: just cleaned 4 carbs
12:42 AM anonnumberanon: well like i said ill tear it down and see what's wrong
12:42 AM rue_shop3: arg, that totally reminds me I need to crash my copter more
12:42 AM rue_shop3: I can help you fix it
12:42 AM rue_shop3: its just an engine
12:42 AM anonnumberanon: if this works it will make a whole many young cousins happy
12:42 AM rue_shop3: fuel, compression, spark
12:43 AM rue_shop3: (less spark cause its a diesel)
12:43 AM anonnumberanon: \yeah rue_shop3 im going to france in 2 weeks and will stay 2 weeks ill still be on irc
12:43 AM rue_shop3: k
12:43 AM anonnumberanon: ill let you know of the progress on the teardown
12:43 AM rue_shop3: ugh
12:43 AM rue_shop3: if (circle) throw
12:43 AM anonnumberanon: plus will post videos of the flight and? crash :)
12:44 AM anonnumberanon: i don't think it had much compression iirc
12:44 AM anonnumberanon: new spark plug, good gas, gas lines not plugged
12:45 AM anonnumberanon: what's wrong when compression is wrong?
12:45 AM rue_shop3: "rue@blackie2:/home/rue# man date DATE(42) NAME dating a girl, chapter 1 "
12:46 AM rue_shop3: anonnumberanon, carb will be plugged
12:46 AM rue_shop3: and your likley to wreck a valve or gasket if you just tear into it
12:46 AM anonnumberanon: oh..maybe
12:46 AM anonnumberanon: i remember gas was coming out of the exhaust
01:08 AM rue_house: flooded
01:09 AM rue_house: they need cooling or they overheat real quick
01:17 AM rue_house: if I really want to start building the new cnc, I should jsut do it
01:17 AM rue_house: it dosn't matter if it becomes another unfinished project, I'll learn things
01:17 AM rue_house: and maybe I'll finish it
01:17 AM rue_house: and I'll ahve another cnc machine
01:19 AM rue_house: grr sleepy again
01:20 AM rue_house: damnit, I wish wolfram alpha were still up
01:21 AM rue_house: gonna have to isolate my own damn formulas now
01:22 AM rue_house: damnit, google cant do it yet
01:31 AM Luminax-Work is now known as LuminaxWk
01:32 AM anonnumberanon: waaat it's down?
01:32 AM anonnumberanon: why?
01:37 AM rue_house: it dson't work anymore from any browser I can find
01:45 AM mrdata: whats down
01:46 AM mrdata: wait
01:46 AM mrdata: works for me, http://www.wolframalpha.com/
01:53 AM rue_house: ah working from chromium
01:53 AM rue_house: now
02:09 AM rue_house: ok, I have to think
02:09 AM rue_house: I have the time and position of the velocity changes
02:09 AM rue_house: for constant acceleration
02:09 AM rue_house: x=
02:10 AM rue_house: *I have a black book for this*
02:10 AM rue_house: (this is bad)
02:10 AM rue_house: cant find black book
02:10 AM rue_house: damn
02:10 AM rue_house: x=v*t
02:10 AM rue_house: 5m/s * 1s = 5m
02:10 AM rue_house: ok
02:11 AM rue_house: v = a*t
02:12 AM rue_house: sound right
02:12 AM rue_house: substiture
02:12 AM rue_house: te
02:12 AM rue_house: I want x, t, and a
02:12 AM rue_house: x = (a*t)*t
02:12 AM rue_house: x = at^2
02:12 AM rue_house: ok
02:12 AM rue_house: isolate for t
02:13 AM rue_house: x/a=t^2
02:13 AM rue_house: dont want to square root...
02:14 AM rue_house: oh well
02:14 AM rue_house: t = sqrt(x/a)
02:15 AM rue_house: I'd have a hard time noticing if I were the last one alive
02:15 AM rue_house: thats cause you dont get out much
02:15 AM rue_house: pff
02:35 AM anonnumberanon: cause square root is expansive?
02:36 AM anonnumberanon: rue_house,
02:36 AM anonnumberanon: not sure if you're writing a program right now, as you might have guessed
03:23 AM rue_shop3: partly
03:23 AM rue_shop3: yea, I need to work it all out now, I'm sure there is a way to work out the time without a square root
03:24 AM rue_shop3: but right now I'm stripping down circuit baords
03:24 AM rue_shop3: its 1am
03:24 AM rue_shop3: I'll prolly stop soon
03:24 AM rue_shop3: the soldering gun needs a break
03:25 AM rue_shop3: 8200, only supposed to be used for like 3 mins and then given a 15 min break
03:25 AM rue_shop3: so I use it for an hour and go to bed for 8
03:25 AM rue_shop3: er
03:25 AM rue_shop3: no, must be longer
03:25 AM rue_shop3: hmm
03:26 AM rue_shop3: well, there are whole days I dont use it, that must count for something
04:00 AM anonnumberanon: what is the resolution of x/a ?
04:01 AM rue_house: 1
04:02 AM rue_house: 1 unit, I'll work out the mapping to the real world later
04:11 AM anonnumberanon: ah
04:15 AM anonnumberanon: i am bed
04:26 AM veverak is now known as spanish_inquisit
04:37 AM rue_bed2: yea
04:37 AM rue_bed2: 2am
07:56 AM spanish_inquisit is now known as veverak
09:45 AM cfoch-always: hi
09:45 AM cfoch-always: how is the case of a robot called?
09:52 AM robopal: chassis
09:52 AM robopal: what else do you mean
09:52 AM cfoch-always: yes
09:53 AM robopal: you can also refear to it as robot body, the `shell', ...
09:53 AM robopal: refer*
09:55 AM cfoch-always: how much can it cost to make a waiter/waitress robot?
09:56 AM robopal: you mean move between tables and serve?
09:57 AM cfoch-always: yes
09:58 AM robopal: between $34.565 and $4billions
09:59 AM cfoch-always: why?
10:00 AM cfoch-always: ah
10:00 AM cfoch-always: yes I know
10:00 AM cfoch-always: robopal: something like https://www.youtube.com/watch?v=zOWpeuxfQMk
10:01 AM robopal: anyway a waiter is not very efficient, you can just pass along food on tables in conveyor belts
10:01 AM robopal: there are already some interesting robots that cook or serve drinks though
10:02 AM robopal: still, to me personaly, I dont see the point, just let the college student do it :-/
10:02 AM robopal: do the job the robot does, I mean
10:03 AM robopal: those crazy asians :D
10:04 AM cfoch-always: I think that a robot that a moer futuristic and a better experience to customers
10:04 AM cfoch-always: o at least a different experience
10:04 AM robopal: different yes
10:05 AM Snert: the liability would be a challenge.
10:05 AM Snert: lessened if it were a low, mobile serving tray
10:06 AM Snert: but a bot walking around with my hot coffee? It better not spill, fall, Equake....you name it.
10:07 AM ib0t: cfoch-always: put a robot chasis which is build out of a cardboard on a lego train and you have the same thing
10:08 AM Snert: I'm not gonna watch a cardboard box deliver my order
10:08 AM Snert: ithat's just not acceptable. Stainless steel at least.
10:09 AM Snert: so...how much could it cost to do a waitress bot? Quite abit.
10:13 AM ib0t: and on the other hand around you could build a waitress bot which is quite more sophisticated as the one in the video for example a robot that can localize itself inside of the room and moves more free without the need of this rail system, it could really recognize people, ect. than including developing cost it would be quite expensive
10:16 AM Snert: I know I sure don't realize all the development costs it takes to bring something to market.
10:39 AM cfoch-always: what simulation software can I use?
10:39 AM cfoch-always: for arduino
10:39 AM cfoch-always: arduino mega
10:40 AM cfoch-always: also I'd like to simulate the behaviour of it with the chassis or body of the robot
10:59 AM SpeedEvil: ib0t: But the development cost is paid once.
10:59 AM SpeedEvil: And can in some cases be paid once globally.
11:00 AM SpeedEvil: Also, the waitress bot can cost quite a bit.
11:00 AM SpeedEvil: Cost of one waitress over 5 years is of the order of $100K
11:02 AM SpeedEvil: And if you've got a chain of restarants employing 10000, half of which can be replaced, suddenly you're into rather large amounts of money.
11:06 AM rue_house: esp if you have to pay them unemployment
11:25 AM rue_house: :P
11:27 AM rue_house: ok, I know the time and position of the two points on a trapazoidal velocity profile
11:27 AM rue_house: keeping this academic
11:27 AM rue_house: (aka, ignoring real world factors)
11:28 AM rue_house: no it looks like I'm stuck with the square root
11:29 AM rue_house: ok, so, for the acceleration period, for a given X, t is sqrt(x/a)
11:30 AM rue_house: ok
11:30 AM rue_house: next is the jog period
11:30 AM rue_house: we know that were past the t1,x1 point on the profile
11:31 AM rue_house: so its just x = t*v
11:31 AM rue_house: (+the t1, +x1)
11:31 AM rue_house: we need to isolate for t
11:31 AM rue_house: uuuuuuuuh
11:31 AM rue_house: (just kidding)
11:32 AM rue_house: t = x/v
11:32 AM rue_house: in this case, we need to adjust by
11:33 AM rue_house: Xcalc = Xin - x1
11:33 AM rue_house: and Tout += t1
11:34 AM rue_house: so, the deaccel gets all complex
11:34 AM rue_house: cause we have an initial velocity
11:35 AM veverak: hmm
11:35 AM rue_house: and I cnt find my black book
11:35 AM veverak: how should one implement priority queue
11:35 AM veverak: or where I can found one
11:36 AM rue_house: look at PIC's (Priority Interrupt Controllers)
11:36 AM rue_house: read the docs on them
11:36 AM rue_house: 8259 I think
11:37 AM veverak: interesting
11:37 AM veverak: need to paralelize search in graph
11:38 AM veverak: somehow I suppose that priority queue insert/pop/decrease-key are the biggest problems
11:40 AM rue_house: aha
11:40 AM veverak: or
11:41 AM rue_house: vf = v1 + (a*t) that makes sense if a is negitive, which it is, yay
11:41 AM veverak: that graph is generated in lazy way
11:41 AM veverak: so it may sense
11:41 AM veverak: to put priority queue in one thread
11:41 AM veverak: and graph generator in second thread
11:41 AM veverak: *makes sense
11:43 AM rue_house: hmm I dont know the velocity, I just know the position... hehe
11:44 AM * veverak is still lost in rue_house problem
11:44 AM veverak: hmm, good point is
11:45 AM veverak: I need to be able to scale it only up to 8 threads
06:36 PM zhanx: rue_house: 4.0uC of Am241? um not a clue