
Berkeley Blue – Accelerating robotics through low-cost hardware - hugs
https://www.berkeleyopenarms.org
======
msadowski
Very, interesting project! I found it so inspiring that I included it in the
Weekly Robotics #34 that is live since 30s ago
([https://weeklyrobotics.com/weekly-
robotics-34](https://weeklyrobotics.com/weekly-robotics-34)).

For anyone interested here is a link to the paper:
[https://arxiv.org/abs/1904.03815](https://arxiv.org/abs/1904.03815) . Having
robotic arms for <$5k would be great for research, hobbyist and applications
not requiring crazy accuracy. I don't have hard data at hand but I doubt that
at present you can find commercially available robot with similar
characteristics for less than $15k.

Another thing that's happening here and I really enjoy is how BLDC motors are
being used in applications like these. The reason I like it so much is because
hopefully there will be a market for cheap actuators that will do the job well
enough to be used for some applications. I'm pretty sure that among other
things I've seen a lot of BLDC based actuators on quadruped robots.

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mtw
Are there any "hobbyists" who can afford a robot arm at $5k?

~~~
msadowski
I'm sure there are some. Also if this robot arm with 7 DoF costs $5k, where
about 70% of the costs are related to motors and electronics then how much
would a 4 DoF arm cost?

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aerophilic
Abstract— Robots must cost less and be force-controlled to enable widespread,
safe deployment in unconstrained human environments. We propose Quasi-Direct
Drive actuation as a capable paradigm for robotic force-controlled
manipulation in human environments at low-cost. Our prototype - Blue - is a
human scale 7 Degree of Freedom arm with 2kg payload. Blue can cost less than
$5000. We show that Blue has dynamic properties that meet or exceed the needs
of human operators: the robot has a nominal position-control bandwidth of
7.5Hz and repeatability within 4mm. We demonstrate a Virtual Reality based
interface that can be used as a method for telepresence and collecting robot
training demonstrations. Manufacturability, scaling, and potential use-cases
for the Blue system are also addressed. Videos and additional information can
be found online at berkeleyopenarms.github.io.

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TaylorAlexander
Looks like some great hardware! I love the simple joint design and the
variable impedance. I hope sales are successful and this venture is able to
perpetuate itself!

~~~
Animats
Yes. The drone and drone camera industry has made 3-phase brushless DC
servomotors with position encoders into consumer products. This robot uses
camera gimbal motors. Most previous robots in this size range used either more
expensive industrial motors or variations on R/C servos like the Dynamixel.

There are many Dynamixel based robots. It's basically an R/C servo with an
encoder and a useful communications protocol. It's a fast motor with a lot of
gear reduction, not very back-driveable, certainly not enough for force
feedback. Typical pricing is in the $1000-$2000 range. The tier below that is
robot arms with regular PWM R/C servos. I have a UArm like that on my desk.
Repeatability is about 5mm. Costs a few hundred dollars. Not back-driveable at
all.

Servomotors and motor controllers used to be incredibly expensive for what
they do. Over $1000 for a motor controller was not unusual. The actuation end
of robotics is getting cheaper, at last.

~~~
fest
Motors from hobby market with custom controllers + belt reduction instead of
precision strain wave gearboxes seem to be major cost-reducers. Less
precision, but lower cost. More than good enough for perception and control
research on how to perform everyday chores.

~~~
Animats
What makes this work is that the better hobby motors for drones are now pretty
good. Hobby motors used to be cheap sheet metal junk.

~~~
TaylorAlexander
(Brushless) Hobby motors are typically CNC's aluminum and steel these days.
Some sheet metal ones exist too. High quality closed loop controllers shipping
in volumes helps too. The cheap motor factories can make higher quality motors
upon request too so "hobby like" motors can be great in robotics if a big
buyer sources them right.

~~~
Animats
_" High quality closed loop controllers shipping in volumes helps too."_

Yes. Those things used to be way overpriced. I was at an industrial trade show
some years ago, and saw that Maxon, a motor manufacturer, had added
controllers to their product line. I was chatting with the sales rep, and he
said they'd added them because they were tired of selling $100 motors that
were used with $1000 controllers, when motor and controller cost about the
same to make. Selling both together resulted in a huge improvement in profit
margin.

Encoders, too. For a long time, shaft encoders, which are very simple devices,
were way overpriced. They were separate from motors, which meant you usually
needed a motor with a shaft out each end, plus the parts to attach motor and
shaft, plus the alignment problems of keeping two things with separate
bearings concentric. With the encoder built into the motor, this all gets much
simpler and neater.

~~~
TaylorAlexander
Seriously. I dream of hobby motors with built in high resolution encoders in
the sub $100 price range. That and a programmable closed loop brushless
controller for under $50 would be so impactful.

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hellllllllooo
Define low-cost? What sensors are being used in the video?

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detaro
According to the paper, "can be <$5000 if a run of >1500 is made"

~~~
monkmartinez
That seems ridiculously expensive. How much is a Universal Robotics "Co-Bot"
or one of Kuka's lower end models?

~~~
contingencies
There are a ton of industrial robot arms available in China in the last few
years. Examples:
[https://item.taobao.com/item.htm?id=572669195615](https://item.taobao.com/item.htm?id=572669195615)
@ USD$3550,
[https://item.taobao.com/item.htm?id=588690121022](https://item.taobao.com/item.htm?id=588690121022)
@ USD$3850,
[https://item.taobao.com/item.htm?id=572700770567](https://item.taobao.com/item.htm?id=572700770567)
@ USD$4100,
[https://item.taobao.com/item.htm?id=589952267004](https://item.taobao.com/item.htm?id=589952267004)
@ USD$4251,
[https://item.taobao.com/item.htm?id=582638257935](https://item.taobao.com/item.htm?id=582638257935)
@ USD$10000, etc.

Some advertise using imported SMC (Japanese) pneumatic/hydraulic mechanisms.

This may not be unrelated to the fact that you can buy a fully detailed
product model like
[https://item.taobao.com/item.htm?526498275889](https://item.taobao.com/item.htm?526498275889)
or
[https://item.taobao.com/item.htm?id=571064427455](https://item.taobao.com/item.htm?id=571064427455)
for USD$0.30+.

~~~
amelius
There is one important difference: article's robot is human-safe.

~~~
contingencies
Sure but simple presence / proximity type sensors are cheap. As are cameras.
Human-safe is then basically a software feature.

IMHO the whole 'cobot' media fad and deployments with humans are needlessly
complex versus just handing over between dedicated human-only and robot-only
motion envelopes.

In industrial or small-scale automation settings, useful for a subset of tasks
at best. For these special cobot cases, why not use a retrofit kit for third
party arms? It makes more sense as would be more loosely coupled with
inevitable hardware evolution and provenance.

Hell, it'd even work with arbitrary industrial gear. Talk about a large
retrofit market.

Software people: that's a valid (and high fad-factor!) startup idea. Get some
VC and go get 'em.

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harperlee
Awesome. But I think the real revolution in robotics is when tact can be built
in throughout the arm. Feeling force feedback in each joint is one part of the
equation; but tact is the way that subtle manipulation, precise feedback and
deep environment status understanding will close the gap with human
manipulation.

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ilaksh
Berkely also has some interesting research on embodied AI.

My belief about robotics is that we need really efficient and powerful
artificial muscles and closer biomimicry. It seems like the way real limbs
operate with leverage will be an advantage if we can get useful muscles.

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ingend88
Are there any DIY robotic arms that you would recommend below $1000 ?

~~~
syntaxing
Depends on your payload and complexity of what you want. There are a couple of
design on Thingiverse that uses hobbyist RC servos. The total cost should be
less than $100.

~~~
ingend88
Can you point me to them ?

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syntaxing
They can range expensive to around $200 [1] that is like Universal Robotics
clone to really cheap using hobby servo that cost less than $30 [2]

[1][https://www.thingiverse.com/thing:3327968](https://www.thingiverse.com/thing:3327968)

[2]
[https://www.thingiverse.com/thing:360108](https://www.thingiverse.com/thing:360108)

~~~
ingend88
Are there any prebuilt ones?

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amelius
In the video, the robot is remotely controlled.

How long will it take until reinforcement learning / ML can do these things
automatically?

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agumonkey
Will robotics be 2050s version of 1950s kitchen appliances ?

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nmca
Is there a MuJoCo model?

