Having already made it to three hardware development versions, [Toby Baumgartner] is looking for some financial backing to make version four of this robot arm possible.
He’s modelling the arm after much larger ABB industrial robots. Like those, it mounts on a stationary base, and features movement along six axes. The first couple of iterations even used ABB Software’s RobotStudio for control. This is the same software used by the full-sized robots, and features a special design language to integrate the robots into just about any production facility.
We don’t think the need for high-end software used with these small manipulator arms is very great, but we could see the finished product used for small-scale assembly line work some day. In the mean time these might be useful in your own projects. [Toby] has been using an mBed microcontroller board as the hardware driver. It communicates with the computer via an Ethernet connection and he’s even working on an Android interface right now.
Check out a video demonstration of version 2 and 3 embedded after the break.
[youtube=http://www.youtube.com/watch?v=yKBx3fmdeH0&w=470]
I wanted to do this about a year ago when i worked at a automated factory. I was going to use the money I was making there to finance the foray into the R&D for it, but the automotive market crashed. God speed to you. If you happen to finally make a version that can put another arm together it will be the first real reprap. just imagine, an army of robots that manufacture themselves! MUAHAHAHAHA!
Just an observation. Your movements appear to essentially step functions (on off). That’s what’s causing the jerkiness. You need some control system tweaking.. Maybe a gradiated accel/decel routine.
Tweeks
Jerkyness is caused by RC servos. If he’d use the robotics servos like Dynamixel it could solve most of his issues.
How about putting some kind of damper on each servo to smooth out the jerkiness? Some kind of viscous bearing perhaps? “Oilite” bushes are pretty useful for smoothing out motion, I’m using some on my 2D plotter rails and the motion is really slick.
I like the ambition of this and the direct ancestry between the industrial robots and this small model. Using the professional control software is actually more impressive to me than the robot itself. Well done.
Even RC servos shouldn’t be jerky like that if commanded with the correct joint profile – I think it’s just poor joint control rather than hardware – it’s a tough thing to get right. I’ve had a full scale arm jerking like that through my poor initial attempts to do joint control :)
alot of the jerk and wobble seems to be a lack of balance in the parts. too heavy a servo package hanging on a small section of plastic. beef up the frame to solidify it and the servo torque wont cause that type of resonance/vibration.
Yes, the servos and motion is quite jerky, these versions have less than $50 dollars invested in cheap servos, and the frame isn’t very beefy. These versions were mainly a proof-of-concept; the main goal was to develop the interface between ABB’s Robot Studio and the miniature robot. I just ordered some Dynamixel servos and am raising additional funds (through KickStarter) to build a much improved TROBOT 4.0. I have plans for an improved controller in the works as well. As long as the Kickstarter project gets funded, I will have a much smoother TROBOT kit available in about 6 months.
toby, the solution to the jerkiness is simple and cheap:
http://www.pololu.com/catalog/category/12
i have used this with my robot arm
groovy .. its like my the old super armatron toy i hacked .. but O_O complecated
Hi all,
its great to see some good experimentation around 6 axis robot. Why not try simulating such experiments using RobotStudio. RobotStudio software from ABB helps to simulate 6 axis robots. We have a large range of variety of 6 axis robots too. TO find out more – check us out at facebook.com/robotstudio
Look forward to see you there soon.