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This is a quite typical misconception on the robotics field: robots have a good repeatability but an awful precision.
After years of working with them I've learnt to expect a 0,3mm precision in all the working envelope as the best case scenario and only in certain robot arms (the smallest ones). And of course after a very expensive recalibration process that can take a couple of days per robot.
You can easily see Absolut/High accuracy robot variants in all the robot brands out there and in those "special" much more precise systems they are offering +-1mm of precision.
when you move a robot to a certain position and store the point you are simply correcting the precision error without even noticing it, but don't try to copy one program from one robot to another one... even in the same conditions the program will be executed in a different position...
A CNC machine is always more precise than a robot (of course if it has been constructed as it should), but the way the motors and the physical conception of a robot is made it is easy to understand the big kind of errors a robot have.
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That's good info and a point well made. But "...but don't try to copy one program from one robot to another one... " doesn't hold for many cases, especially when the robot is integrated with sensory and other features that give it the ability to correct where needed. With that environment in place, I can move the software and its specific operating scripts from one unit to another and get the needed performance. Glad you mentioned CNC machinery (a large part of automation and AI that is not in the forefront of the IT news).
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It all depends on your needs of course, usually this is not needed and sensors can help to correct the robot programs. In our case (we always make strange things) we need to allow the end-user to program the trajectories in order to be able to create different programs depending on the different parts the machine will have to grind or polish.
When this happens, given the fact the robot precision errors are not constant in position nor orientation, then we need to go the re-calibration way.
If you take a look at our EMERALD machine range you'll see why I speak about copying one program from one robot to another one.
Anyway, if we forget our strange needs you are right.
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Nice!
Not sure there ae many robotic opportunities in Australia.... but gonna investigate!
Thanks for your inspiring email!
+ on top of year of IT experience I study physics, which is a nice and meaningful background to have in that topic, I bet! :P
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Be aware that you will have to spend nights and plenty of stress on the deadlines... programming is done while the project is growing up, but the final tests and set up is done at the end, when all the money has been spent and usually being late at the starting point.
It's fun and nice, but this is the worst part of it.
Sure it can help.
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"...they are not precise ..."
Consider the Motoman HP20-6, within it's range of motion repeatability is +-.06MM, industrial robots - love'em. If you want to be involved with robotics, vision, sensors and creating the software to drive and integrate them, get into manufacturing.
regs
ron o.
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Hello bojammis,
See my other answer here[^].
Precision is not the same than repeatability. A lot of years ago I learned that the hard way.
And then, it comes when the repeatability sphere changes it's physical position depending on the motors temperature...
I've still never used Motoman, but I've used ABB and KUKA extensively (since 1999) and now I've started using Stäubli (because of a customer preference). Soon it is possible I'll have a Motoman to play with... let's see if they work as well as I heard and let me cross fingers to pray for a software base that looks like the one installed in ABB.
+-0.06 is not precise by any means, any of our tailor made CNC machines is at least 10 times better in precision than that.
Don't misunderstand me, I love robots: they are really flexible and allow making things that are impossible or super expensive if you have to do them in a CNC/PLC tailor made machine. We've made very special things with them, extensive math, processes that recalculate the trajectories at runtime, calibrating robots, artificial vision, force control sensors, offline programming... we even have some patents related to robotics... Feel free to take a look at our web page (see my signature) and some videos in our Youtube channel.
Which sector are you in? which kind of machines do you create at your company?
Best regards!
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I'm making this comment after I replied to the (answer)link you sent me so it may seem they are out of sync. I worked with CNC equipment for 25 years. Very use to the idea of +=.0002 inch accuracy with .00004 repeatability. I don't meet many people who have had the experience and back ground that you sport( in automation). My experience with CNC equipment was end user at the time. Now I work with automation for micro circuits(chips). I write software that would manage/coordinate a number of robots (in atmosphere and in high vacuum) along with heaters, gas analyzers, cryogenic doDads, digital IO devices, devices that communicate using sockets, the list goes on. These are machine specific to the needs of the company. But it's great fun.
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bojammis wrote: But it's great fun.
Indeed it sounds fun, once you enter the physical world it's difficult to go back to program "normal" programs.
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You might want to check out Instructables. There you can do a search on Robots, Raspberry PI, Audrino, Intel Edison, and (my fav) Segway. This site is perfect for DIYers. Truly a great place to start fishing for ideas and learning how other people make things.
Hope it helps.
Phil Delay
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When my better half bought an iRobot Roomba, it came with an invitation to develop new programs for it. It's fun to watch one of these when you first get it, in part because there are just a few easily identified floor coverage algorithms. And they're way different than anything I expected.
Maybe all it can be programmed for is movement patterns, but for 400 USD it might be fun and you would see some tangible results.
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A bishop moves "diagonally" -- that's good one-word description.
Is there a generally accepted one-word description of how a rook moves? "Horizontally", "vertically", and "perpendicularly" don't seem correct. "Straight" seems too vague.
P.S. I'm going with "orthogonal".
modified 14-Oct-15 23:10pm.
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I've seen horizontally, vertically mentioned in the same breath, as Ive seen 'forwards, backwards and to the sides', and then 'horizontally and vertically both forwards and backwards' - so if you want one word, horizontally and vertically arnt too bad
Perpendicularly .. hmmmm
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Garth J Lancaster wrote: horizontally and vertically
But I seek one word that covers both.
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Yes, a very good word for this situation.
The pieces cross the divisions of the board at right angles to them.
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Over yonder!
New version: WinHeist Version When you have eliminated the JavaScript, whatever remains must be an empty page. Unknown
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That sounds more like a shuffle board term. You've been in Florida too long.
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PIEBALDconsult wrote: You've been in Florida too long.
30 years! I think I'm starting to rub off on them!
New version: WinHeist Version When you have eliminated the JavaScript, whatever remains must be an empty page. Unknown
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Which way does your chad hang?
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To the south of course!
New version: WinHeist Version When you have eliminated the JavaScript, whatever remains must be an empty page. Unknown
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It hangs so far south it's started to go north.
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