There really hasn't been as much progress in hobbyist-level
hardware in the past twenty years as there should have been.
Computing has advanced enormously, yet most hobbyist robots are
still using Polaroid sonars, analog R/C servos, and
Basic STAMPs from the 1980s.
First, R/C servos. They're still used mostly as output-only
devices. Although it's possible to tap into them and get
out position and torque information, this is rarely done.
Rod Brooks did it at MIT for his insect robots, but that
doesn't seem to have trickled down. Some of the newer
servos have CPUs in them, and reasonably good ones, like
Atmel CPUs. Some can be reprogrammed. That's something to
work on - find an R/C servo that can be reprogrammed into
communicating bidirectionally in some intelligent way.
Sonars. We have enough compute power today to do serious
sonar processing, like submarines do. But mostly, people
are still just pinging with 30 degree beam widths, just like
the 1980s. That's disappointing. We should have bat sonar
by now.
Motor controllers with positional feedback generally are
still too expensive, as are motors with encoders.
Acroname has some cheap encoders, but they're not
well integrated with motors.
We do have cheap cameras, and more is being done with them,
so there is progress. But you still can't buy Aibo-grade
components off the shelf.
John Nagle
John Nagle wrote:
I'll skip most of your comments and jump straight to:
Sure you can. It's simply a question of money and interfacing. COTS
parts get cheaper the more people buy them. The fact that these parts
are still expensive [in a usable form] is because not enough people are
buying them. This suggests that hobbyists are uninterested or incapable
of building the heavy signal-processing applications you describe. If
you want a 3Mp CMOS image sensor, you can buy a camera containing the
part and cannibalize it, or you can use a computer (or SBC) to
interface to it. Apparently not enough people are doing this.
In the same vein, many kids build go-carts. Few kids build fully
functional Lamborghini replicas.
By the way, do you have an anechoic chamber for calibrating your
side-scan sonar? Have you built a laser scanning video system? Does
your latest robot have a complete strapdown inertial guidance platform
in it (you can buy a very complete one for about EUR1500)? Have you
considered cannibalizing a dual-tech PIR to use as a radar rangefinder?
Well, actually I ran one of the DARPA Grand Challenge teams,
Team Overbot. We did have a complete inertial guidance platform.
(The three-gyro, three accelerometer units are getting cheaper
very rapidly.) And I did build a LIDAR around 1992, but it was a dud;
for the Grand Challenge we used a SICK LMS, which is ten year old
technology but very ruggedly built.
What strikes me is how much cheaper high-end gear became during the
three years of the Grand Challenge. Precision GPS/INS/compass/odometer combos
were $100K when we started, and are now down to $6K. One of the
Trimble guys told me their goal is to drop the price by an order
of magnitude every five years.
At the IC level, part cost and
availability has improved enormously. What we're not seeing is
comparable progress at the board, subsystem, and system design level.
Acroname is trying, model helicopter guidance is making real
progress, and some of the robot toys are quite well designed,
but the mid-level components aren't there yet.
John Nagle
He said: "What we're not seeing is comparable progress
at the board, subsystem, and system design level".
I envision something like CAN, a universal communication
language and interface for robotic components that's
cheap enough for the simplest sensor and powerful/fast
enough for everything, perhaps short of video. The idea
being that every robotic brain would have an interface
and language/OS that understands it, so you don't spend
your time fiddling with squillions of little interface
details, tracking down ground bounce communication
problems because your SPI lines are too long, etc, but
can simply get on with the job of making your device do
what you want it to.
I reckon it could be built on multi-drop RS-485 more
cheaply than CAN though...
Clifford Heath.
Clifford:
I am working on another set of robotics modules based on
microcontrollers with embedded UART's and CAN Bus physical
layer. Here's the URL:
<http://gramlich.net/projects/rb2/index.html
It is definitely not ready for prime time, but we are
starting to see some solid progress. We are reliably
sending data over the bus at .5Mbps. Yeah, there could
be more documentation, but there are only so many hours
in the day.
Enjoy,
-Wayne
Looks neat, I think -- it'd be great if you could spare 15 minutes to
type up an overview of what the heck it is, and maybe post some photos.
A newbie like me can't really make heads or tails of it, except that it
seems to be a set of modules that work together somehow. That in itself
sounds good, so I encourage you to keep it up!
Cheers,
- Joe
Joe:
Fair enough request.
The concept behind RoboBricks2 bus is to strike a balance
between ease of use *and* ease of implementation. The
concept is that new users would feel confortable plugging
together modules designed by other people, but more experienced
robotics people should feel pretty comfortable designing
a new module that plugs into the bus as well.
The 5 most heavily discussed options were:
1) I2C
2) SPI
3) UART on top of a) RS422, b) RS485, or c) CAN bus
physical layer
4) CAN bus full stack.
The desire for a high noise immunity bus pretty much
ruled out I2C (1) and SPI (2). We liked full CAN bus
(4), but it was viewed as difficult to implement modules
for since it basically needed a pretty complete set of
hardware support inside the microcontroller along with
some substantial software support. The advantage of
using a UART (3) of UART's is that they are both ubiquitous
and easy to use. Doing UART support in assembly code
is still relatively easy; whereas CAN bus support is not.
Thus, UART (3) won out over full CAN bus (4). The choice
of RS422, RS485, vs. CAN bus physical layer was based on
ease of module implementation. The CAN bus transceivers
do not need to have a pin that specifies whether your
module is transmitting or not.
The bus is currently using 10 conductor insulation
displacement connectors (i.e. 2x5 headers.) The
headers are polarized to prevent plugging in backwards.
Again, there was a huge amount of discussion about
connectors, and the choice of 2x5 connectors was based
on ease of use and availability. There are actually
two power buses on the ribbon cable -- one regulated 5V
for the logic supply and one 6V-12V for direct connection
to a battery. Devices that have nasty power surges are
required to keep their surges off the logic bus via
opto-isolators; this includes motors, servos, Sharp GP2D12's,
etc.
The RoboBricks2 bus hardware design is fixed and will
not be changed. If you do not like it, please feel
free to design your own bus and modules that plug into
it. Honestly, I will not be offended.
The software architecture is pretty simple master/slave.
Each slave module has a unique 8-bit address on the
bus. A master sends out module address select byte,
followed by a number of commands to query the slave
module. There can be multiple masters on the same
bus, but only one can be active at a time. When one
master is done, it contacts the next master and hands
off control to it. There is no collision detection
hardware or software.
The bus is currently running at .5M bits per second.
It is felt that this is fast enough for everything
but pumping video frames. If people want to do
video, they will have to use some other bus.
While the summary above took longer than 15 minutes
to type in, it should provide enough of an overview.
With regards to pictures, the only two pictures I could
find of a robot that uses RoboBricks2 technology is at
Camp Peavy's site:
<
http://www.camppeavy.com/sitebuilder/images/06june76-260x176.jpg
The pictures are too small to be of any real use. I'll
put posting of some pictures on our "to do" list. It will
take a week or two before it happens.
Later,
-Wayne
This sounds really cool. I'm still not sure what a CAN bus is, but I
believe I understand that UART basically means a serial bus. So you
have a bunch of modules that can be plugged together with minimal fuss,
sharing power and communications over the RoboBricks2 bus.
I really like the idea of more modular, plug-and-play components. Apart
from Mindstorms, I haven't seen anyone else to do this very well -- and
Mindstorms is rather limited (as a controller, anyway). If you can do
something similar but with more options, and (ideally) with a lower
entry barrier (in cost), I think you'll have a big hit.
Yes, and I appreciate it (and hopefully there are others here who do,
too). Will these be commercially available, or just public designs, or
what?
Best,
- Joe
That's the idea - the symmetrical connector and power+logic
arrangement is useful. It's almost a shame that it won't
"just work" either way actually! That'd be cute.
I would have made the software protocol a little more
sophisticated, adding a discovery (devices + capabilities)
protocol and the possibility of sending short packets rather
than just 9-bit bytes. With packets, you can drop to 8-bit
byts to make coding easier too.
Consider that it's the software pluggability as well as the
hardware that matters. There was a good protocol discussed
here a while back of which I can't remember the name.
The kind of thing you need is to be able to say "identify
yourself, #47" and get back a descriptor from a standard
set like "H-Bridge, up to 3A, with current sense return
data", "servo, 270 degrees range, 180 degrees/sec, 4Nm
max torque", or "compass, 3 degrees resolution".
But basically, all it needs is a bit more definition and
some vendor willing to make a cheap range of modified servos,
sensors and a CPU board (or adapter H/W), and you could get
the platform established and moving.
Clifford Heath.
Here's a perspective from a newbie (well, really more of a wanna-be) to
the hobby, FWIW.
First, controllers: I've seen a lot of alternatives to the Basic STAMPs
coming out lately. Pololu has their great Orangutan boards, LEGO has
the new NXT, other people are using OOPICs or whatnot. I also carry
around a lot of computing power in the form of my PalmPilot -- I know a
few people have made these into removable robot controllers, though I
haven't seen as much of this as I would expect. Also, there is the XBC,
which is a really amazing controller.
Almost all of this is too expensive for me, though -- if it's not under
$100, I can't get it past the budget committee (i.e. my wife) right now.
Perhaps this is useful data -- there are certainly price-sensitive
hobbyists like me, and much of the current hardware doesn't sell to
them. Conversely, there are hobbyists who are largely price-insensitive
(I know several in my local club), and for that market, lowering the
prices just means leaving money on the table.
At the same time, the folks who are price-insensitive are also often
those with the least ability to put together their own PC boards, power
supplies, and other such hackery required by many of the cheaper
devices. So robotics suppliers are in the awkward position that, to
reach the (probably much larger) casual robotics market, they have to
simultaneously sell a more-complete device and sell it for less money.
I didn't know it was possible at all, except for the new digital servos,
which are way too expensive. Would you have any references on how to do
this? Sounds pretty neat.
Indeed. Wouldn't that basically turn an ordinary R/C servo into a
digital servo, of the sort used by the Robo-One-style robots?
That's interesting. I'm currently working on a laptop bot, which will
have plenty of processing power, as you say. I'm also a software
engineer, and probably up to the task of writing code for any algorithm
I understand. But I don't know what algorithms you'd use to extract
more data from a sonar echo -- again, references would be appreciated.
I think back-EMF is pretty cheap, though to do it at high speed may
require a FPGA, like the XBC. But I too have been surprised at how hard
it is to find decent position encoders for a reasonable price, given
that it seems like such a simple problem.
FWIW, the new NXT motors have built-in encoders with 1-degree
resolution, and cost about $18. However, I don't know how you would
control one of these except from the NXT controller.
Well, that's not necessarily a bad thing -- it lets you mix and match
your motors and your encoders, even getting motors from nontraditional
sources like junked cars or whatever. I do agree that integrated
encoders would be a lot easier, though.
What's the difference between the Aibo components and standard cameras?
I'm planning to put a USB camera on my bot (maybe two, someday), and see
what I can do with it. Vision is another thing that's probably better
done with some pre-processing in a FPGA (again like XBC), but I'll have
to make do with software. I expect to be able to do color tracking, and
maybe motion detection. If I expend a lot of effort, I may be able to
get it to find people and faces in its view. Anything else you think I
should be shooting for?
Best,
- Joe
I think its not so much that new tech isnt available or involve a cost
parameter as
perhaps the level of creative integration. The actual I/O devices old
or new simply
end up doing the same applications over and over. Newcomers often
follow the crowd
(published books on the subject)or try and utilize the plug and play
methodology.
I work "out of the box" on new ways for sensor implementation most
builders might
think unlikely, as well as actuator/motor control devices. I also build
from scratch in
both circuitry and mechanical part fabrication, both unavailable to
many builders
newcomer or not.
It stands to reason you work with what you have of can afford to buy.
Also, I really
dont think information is really shared much between builders. We all
dont write books
or publish what we learn and use, and many just rely on written
resources of those who
do/have. Lots of people here ask questions, or propose new ideas, but
rarely do you
see a thread offer start to finish information on a unique
process.(unfortunate!)
Mark
Joe Strout wrote:
This conversation is pointless. You are correct that hobby robots
aren't as cool as they should be, but you change that by building cool
robots, not by bitching about it on usenet. I will offer my theory,
however.
Lots of cool technology could be cheaply available for hobby robotics
-- machine vision, lidar, advanced sonar, good actuators, fast
computers, etc. But none of it is because there isn't a big enough
demand for making it cheap and hobbyist-friendly. The reason there
isn't demand for it is the result of a cultural change in the u.s. over
the last fifty years. It used to be that people looked at a childen's
chemistry kit and thought "teaching tomorrow's scientists". Now they
look at it and think "personal injury liability". Technology has
changed from cool things you build at home to shiny things you buy at
radio shack. The culture of experimentation has taken another nosedive
lately now that homemade technology is generally assumed to consist of
meth labs and ieds.
-chris.
John Nagle wrote:
I thought it was pointless as well, and I wasn't going to respond. The
idea behind hobbyist ANYTHING is low-cost. Anyone can spend money if
they have it. The fact that products with more capabilities and feature
are indeed available is not an indictment of the progress made, but an
implicit statement about how the nicer things in life are more
expensive. Wow, what a concept!
Absolutely correct. Plus, parents are just as apt these days to buy a
virtual chemistry set, which just isn't the same.
-- Gordon
Who's a hobbiest, what is a hobby, and why should it change?
How do you happen to mix hobbiest and progress as in any way linked?
There hasn't been much change in model railroading hardware in the past
50 years, should there have been there too?
(Interesting subject, none the less.)
From a wikipedia quote on Schumpeter,
http://en.wikipedia.org/wiki/Joseph_Schumpeter
"Schumpeter starts in The Theory of Economic Development with a treatise
of circular flow which, excluding any innovations and innovative
activities, leads to a stationary state. The stationary state is,
according to Schumpeter, described by Walrasian equilibrium. The hero of
his story, though, is, in fine Austrian fashion, the entrepreneur.
"The entrepreneur disturbs this equilibrium and is the cause of economic
development, which proceeds in cyclic fashion along several time
scales."
The trouble with hobbyist-level robot hardware isn't the hobbyist's. The
trouble is with the entrepreneurs. Apparently no one clever enought has
found a way to "disturb the equilibrium" such that they would perfer new
hardware due to available performance.
For me, this is a real kick in the pants, because I am one of those
entrepreneurs trying.
I offered a board IsoPod(TM) that was 20x the power of the Basic Stamp
at about a 1.4x price margin. So the hobbyist could get 11x the
performance for his money.
But I made an active decision to help them along, to not offer Basic,
because from our previous experience selling Basic, we'd found the
customers who were most lost and confused, the projects that were most
often in trouble of not being finished, where the ones using Basic. So I
decided not to offer a Basic.
From the feed back I get, apparently this is why I was not a more
successful entrepreneur "disturbing the equilibrium". Many object to my
IsoMax(TM) state machine based language on top of a Forth substrate. It
is tagged as "Forth based", even by those who prefer C, even though
there are C's available for my product, and the majority avoid it.
(Thank goodness for the professionals, who have embraced the power and
utility in my offering, although they were not the target of my
marketing campaign!)
Now, I can take the approach of blaming the hobbyists for not using
something more advanced, as it appears you do in your openning post, or
I can look inward and ask why I am not a better entrepreneur for not
offering what they wanted in the first place. Or at least this is the
best I can make of the market to this point.
Perhaps you see whay I said "Interesting subject, none the less." I'd
really like to see more discussion on this thread.
Don't knock yourself out. Newmicros offers great products and support. I
know this even though I've never purchased or worked with your products.
It's just that we the hobby people are not into serious research and
developement. We just love to tinker and play. It's good that others
(more professional) have found uses for you products and services. It means
your on the right track. If they can keep your business going then someday
us little guys will follow suit. Keep up the work. Remember nobody five
years ago could have guessed at the succuss of the MP3 player when everybody
in the music industry thought they where useless toys that stole money from
big business. It could/can be the same for robotics.
Was it the language or the type of people that prefer
the language that was the cause of getting confused?
But maybe the professionals had the _expertise_ to
understand and use the products and already had a
useful desired outcome in mind? It doesn't really
matter how good or advanced your products are if a
hobbyist can't see a desired outcome why would they
be interested?
In terms of off the shelf cost effective choices
the only products I have found that would give me
the potential to build the robot I would like is
an electric wheelchair and a laptop. Anything else
lacks the power to money ratio required.
But even these two items lack essential ingredients.
Imagination. Programming skills. Hardware that is
limited to the imaginations is severely handicapped.
The limited market is for toy robots that work. Like
those reptile robots or toy light seeking, line
followers. Just like the train sets you mentioned.
The imagination being limited to plugging off the
shelf items in some configuration.
Advanced robotics which have some future potential
are expensive and require advanced hardware/software
skills not possessed by most people.
Your market is for those that know what to do with
your products and already have the expertise to use
them as a cost effective solution to their problem.
How many robotics hobbyists are of the caliber of
David P. Anderson and could build that really cool
two wheel balancing robot? And why can't I buy one
from the local electronics shop :)
In My Opinion, Evolution Robotics *was* well on the way to do that. They were
developing a nice following from the
hobbyists that bought their ER1, and they had kick-ass customer service. They
took a fairly plain robotic platform,
offered it at recycled parts type price, and added the vision recognition
software that was almost the Holy Grail. But
then the "all important bottom line" kicked in and they abandoned what could
have been a kick-ass, almost free,
marketing tool (the hobbyists) for their more expensive products.
As I stated in another thread, *your* customer service has absolutely blown me
away! If I am buying a part or gizmo that
I am not sure I can handle or troubleshoot on my own, I will buy the more
expensive part from the company with the good
rep - in a heartbeat - before I will buy the cheaper one somewhere else.
In My Humble Opinion, you just hit the nail on the head. The ONLY problem with
your stuff is the marketing. It's obvious
you are one hell of an engineer. But if I didn't already know I needed an
H-bridge I probably wouldn't have ended up on
your web site. Some good "how-to" articles might be a big help. A gallery of
'bots and other gadgets built using your
products would be a big boon, I think. That very gimmick brought me back to the
Acroname website more than once, and I
eventually started looking at their products and bought a couple.
I think the mini-sumo photo and link is a great start. A lot of the content on
your web site seems to be written for a
target audience that already has a good idea of what they need. If you can have
some kind of "branding" device that
appeals to the hobbyist and is associated with your products, that could really
boost your sales and mention in the
press. I've told several people to get a BoeBot kit to get started in the hobby
because it has everything they need to
successfully build a robot. It doesn't matter that your IsoPod is a better
product than the Stamp because the guys
looking for a BoeBot type kit don't even know about the IsoPod. If they stick
with the hobby, and realize that the Stamp
doesn't do everything they want it to do, then they will eventually go looking
for something like the IsoPod. Maybe you
need a "NewMicrosBot" !
The advantage Parallax has is that it has a lot of free press out there, and
lots of web pages showing how someone made
an automated whatzit gage sensor that sounds a horn when it's time to get out of
bed and get in the boat. If you can get
some of that "action" going on, I would think your products will start popping
up all over the place - in technoblogs &
how-to pages.
As for Forth, I fiddled with it about 20 years ago or so, and thought it was
really neat. At the time, the buzz line
that "forth is written in forth" intrigued the heck out of me. But I bet that
75% or more of even the die-hard C/C++
gearheads haven't even heard of it if they are younger than, say, 35 years. I
would suggest some pages that explain what
Forth is; where to find more info on it; and why you chose it for your product.
Personally, I like the control and closeness to the hardware that C offers.When
I am building a robot that might consist
of a mini-ITX mo'board; another controller gizmo to drive some servo motors; and
maybe yet another little processor to
manage drive motor control, I don't want to have to jump between 3 different
programming languages --- even if that
other language has major advantages. BUT, if I can readily see (from your
website) that your particular processor board
might be able to drive my H-bridges AND drive my servos, AND take commands from
a PC mo'board via a serial line, etc.,
then I start thinking that maybe I don't need 3 separate boards that total $350,
but that maybe I can use just your one
gizmo that costs a bit higher than that Basic Stamp but does so much more.
Having said all of that, I have read some of the excellent advice you have given
people on this newsgroup. Put that same
stuff on your website, too, and - I would be spending more time on your website
and probably taking a 2nd & 3rd and 4th
look at that IsoPod or TinyPod, etc.
Another thought is that I have seen one guy that offers a little touchscreen &
controller on eBay at a few bucks off the
normal price. This seems like a great way to do some marketing. Maybe you could
come up with a simple robot kit (even if
you don't supply all the parts but instead have a detailed list) that you can
offer? Once a few hobbyists get a taste of
it, you know they will start adding grippers (maybe from Gordon!) & sensors,
etc., and will be itching to show it off on
your gallery pages.
Like someone else said, you have great products already, and it sounds like you
are a heck of an entrepreneur, too. You
just need to figure out how to get the word out. Marketing might not be your
forte' so find someone who does it well. A
website facelift would help, too. One thing I noticed is that when I wanted to
return to the home page I had to move the
cursor to the address bar and hit enter --- there should a link on every page to
"go home". Also there should be a
search box on every page. ( IMO )
I hope my comments are of some use to you! Others may have other opinions, but I
firmly believe what I have said.
Sometimes I can come across as very critical, so please know that is not my
intention. I'd just like to see your great
products and service get the exposure it deserves !
Sincerely,
James C. Deen
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