the crypt

Hi,
I've read comp.robotics.misc for many years but almost never post, although I did get some good help last year from this list with
an RFI problem I was having on one of my robots.
This past week I was involved in an interesting discussion of PID control loops on mobile robots, in the course of which I posted several URLs pointing to robots and videos of robot behaviors to illustrate points we were discussing.
Because these URLs all pointed to my own web server, I was able to monitor the actual hits and downloads, and I was quite surprised, actually stunned, at the results.
My experience has been that when I have posted such URLs before on sites like the Dallas Personal Robotics Group or the Seattle Robotics Society list servers, not to mention robots.net or slashdot, the number of hits typically runs somewhere from many dozens to many hundreds. For slashdot that's typically tens of thousands, but that is not really a "robot site" so I don't take it as typical of the robotics community.
For the postings last week on this forum, there were exactly two hits.
(As an aside, neither appeared to be from the folks involved in the actual discussion, if I surmised correctly from their subsequent comments).
Perhaps this is not representative of the group as a whole, as I also gathered that some members evidently routinely block messages from others that they consider overly inclined to flame wars and "static."
However, somewhere along the line one of the posters opined that:

and referred to the comp.robotics.misc discussion group as

Is this true? If so, because robotics is one of my loves, it's sad.
Why do you suppose this has happened? Or I'm I reading too much into the paucity of page hits?
best regards, dpa
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dpa wrote:

It's definitely quieter -- maybe more like a mortuary rather than a crypt. But I have noticed the same slowdown in message traffic in most other forums and groups, too.
Interest in robotics comes and goes. It tends to peak every 5-7 years. We had a pretty good run in 1999 to about 2001 or 2002, but things have gotten progressively slower since. I expect things to pick up again in a year or two. However, much of this depends on the introduction of new and interesting low-cost products for building bots -- microcontrollers, sensors, whatever. A $75 vision system would get a lot of people back into the game, for example.
I think there's also the matter of people adding certain posters to their kill file. Not you but others. And it being the weekend, a weekend of college bowl games, etc. (For that matter, don't even think about getting many hits to the site next Sunday.)
I can say I didn't visit the sites because A) I've already visited your sites (on numerous occasions), and B) PID math isn't much of an interest of mine. But just to skew your logs I just visited all of the ones you posted! <g>
-- Gordon
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Gordon McComb wrote:

I think robots are of little interest because essentially most of them don't do much considering their high cost. They are just a fun application for newbies in electronics and for engineers to show off their know how.
-- JC
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JGCASEY wrote:

That might be true if there wasn't any recent interest, but that's not the case. We're talking about how groups like this one aren't as busy as they used to be.
Besides, the group was busier when robots were *more* expensive than they are today. Under a certain threshhold cost is not a major consideration, as long as there's something new. What's missing from your theory is that there hasn't been anything radically new for a while.
-- Gordon
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Gordon McComb wrote:

Yes I was a bit off topic. I had something else in mind. Sorry.
-- JC
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Hi
JGCASEY wrote:

I read this and my first thought was "grrrrrr... no! wrong! robots good! robots good!"
Then I started wondering if maybe you're right. So that made me think, what exactly _can_ our robots do? Hmmmm.
I started to make a list of what hobbiests' experimental autonomous mobile robots can do, now. It's not so easy. It has to be what they can really do, now. That's what people see, that's what they are attracted to.
This is what I've come up with so far:
1. Maneuver.
Move around without getting stuck or hitting things.
2. Navigate.
Go somewhere.
This would have to include everything like line following, odometery, wall following, GPS following, maze running, etc.
3. Acquire a target.
candle flames, ir beacons, bright lights, orange traffic cones. maybe this is also navigation?
4. Pick and place something.
Grip or push things from one place to another.
5. Sumo.
Seems like it needs a class to itself. Or is it just pick and place?
6. Soccer.
likewise. Or just team pick and place?
There are surely more but it seems like I can fit all the things I've seen various hobby autonomous mobile robots do in one of these categories. At least all I can think of at 2am.
But maybe this is really just 2 basic capabilities:
1. Navigate (includes maneuver and acquire)
2. Pick and Place. (includes sumo and soccer)
Is that right? We've built a bunch of mobile pick and place machines? I need to sleep on this. <g>
best, dpa
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dpa wrote: JGCASEY wrote:

What do we do that is different? Are we a bunch of mobile pick and place machines? The common riposte to the question what is the use of xxx is, "What use is a newborn baby?"
One use they have that you left off your list is,
7. Entertainment.
They probably also act to inspire young engineers to the future possibilities for automation.
-- JC
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Boy, John, I'm glad you said that, because I think that is the very most main reason we build robots. Either we find the building and development entertaining, or we find watching the result entertaining. In the case of Mini Sumo, I find both extremely pleasurable.
--
Randy M. Dumse
www.newmicros.com
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dpa wrote:

If we could get a robot to do something truly useful then the large manufacturing companies, always looking for new markets, certainly could. The more robotics becomes a commercial venture the less interest there will be in hobbyists building them.
Why do people build and fly model airplanes? I don't imagine it's because one day they want to build a larger airplane and fly in it; they simply like to build things, they like the learning process, and they like the challenge. They may also like the social aspect of meeting other likeminded individuals, sharing ideas, and enterting contests.
Yet another valid purpose for robot building: Robotics is a unique blend of disciplines that covers three major vocational areas: electronics, programming, and mechanics. That makes it an ideal teaching tool whose usefulness reaches far beyond what the machine actually does. As you've found, kids are thrilled just watching these things move. It's the adult that asks, "What does it do?" And if some little robot gets a kid to take engineering or programming or electronics courses, who's to say the little robot didn't have a useful purpose.
-- Gordon
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I've been a software engineer ( or just plain programmer ) for over 20 years now. Built a few robots that were 90% kit based. Just started building my first one almost totally from scratch. So, I can really get into the software, challenge of working on vision recognition, etc. The MOST fun I have had recently working on the bot is ... drum roll ... cutting threads into the aluminum extrusions with a cheap tapping kit I got from Sears! I got the biggest kick out of doing that and then seeing the parts go together into a fairly professional looking chassis ! For me, at the moment, it is the building and creation of something that I just can not find elsewhere. Later will come the satisfaction of seeing it perform the way I intended - hopefully !
Just my 1.5 cents worth ...
JCD
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Gordon McComb wrote:

What would you want in a vision system? Do you have a feature wishlist in mind?
My wife's cellphone has a 1.3 megapixel camera that is about the size of the eraser on the end of a pencil. It can take still photos, and 30fps movies.
I would love to have one of those for a robot, but 1.3 Mpix x 30fps is a lot of data. I think the only way to deliver that much data would be to use something like high-speed USB (480 Mbps). Not many microcontroller based robots are going to be able to handle that. The minimum system would be maybe a mini-itx.
Intel has announced a new ARM Xscale processor, the PXA271, that can interface directly to a CMOS camera. It runs at 400MHz, has 32MB of RAM and 32MB of flash on chip. It should be able to run Linux with no additional components other than a crystal. It has the integer XMM SIMD instructions, which should give it enough power to do image processing tasks like edge-detection. It is clearly designed for PDAs and cellphones, but it looks like it could be a dandy robot controller with integrated vision. I don't think it is actually shipping yet, and I don't know what the price will be.
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Bob wrote:

Just delivering the data is not enough, to make a vision system, you gotta do something with it as well. My robot is ITX based, and I have been pondering a low-cost vision system for it.
1.3Mpix is pretty high, 1280x1024 pixels is a lot of processing, hell 640x480 is a lot of processing, I would be satisfied with 324x240 at 30fps *and* be able to do something.
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"mlw" wrote

Plain right. My first robot was (well, *is*, since I'm still working on it) based on webcams that were capable of providing 640x480 at a decent frame rate (I'm not sure, but I think it was 16fps) but we decided using 320x200. Even though, because we are using only one mini-itx for everything, we can only run very basic image processing algorithms (pre-processing, edge detection, some frequency analysis, etc). We found that what kills us is not the framerate nor the resolution of the image, but the quality of the image. Because of its cheap construction, webcams don't offer or don't have the capabilities to implement faster shutter speeds, therefore the images we capture are sometimes blurred due to natural robot movement (off road environment).
For the new robot (an ATV) we have a bigger budget, and we bought a pair of professional firewire CCD cameras, with real lenses and shutter speed up to 1/100,000 of a sec. If conditions are right no matter how fast we are, we always get a crispy image to work with. The fact that the lenses are capable of f-1.0 is also a plus.
So, just to complement where mlw was going to, resolution and fps are seldom the critical factors for computer vision.
Cheers
Padu
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A vision system is not a camera. It needs to do image recognition, or at least motion detection and simple blob counting or tracking. Examples of commercially available self-contained units (at a reasonable price) include the AVRCAM and the CMUcam.
For vision you can do a lot with fewer pixels. You don't need megapixel imagers, but color can be useful.
There is no reason why there can't be a complete camera/lens/image processing chipset for about $75. The CMUcam could be that price if they made hundreds of thousands more of them. So, it's a matter of quantity, and those quantities won't happen if the product is only for the amateur robotics market. Those Sharp IR sensors are only afforable because the "real" market is things like copiers and faucets in public bathrooms -- they sell hundreds of thousands of the sensors each year. They'd be $50-70 bucks if they were made in low quantities.
-- Gordon
Bob wrote:

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Gordon McComb wrote:

Thus you use what is mass produced, a PC, which most people have. The cost then is in the radio interface. The adventure is developing the software. It may be beyond a hobbyist to develop new hardware but software development only requires a creative brain :)
There is the commercial inspiration, Evolution Robots, and back in 2001 LEGO Mindstorms Vision Command based on a Logitech camera and its SDK.
The problem is hobbyists may have minimal programming skills and PC products tend to be Microsoft orientated requiring the purchasing of VC++.
My poor robotic base sits in the corner of the room collecting dust waiting for me to develop a vision system sufficient for its needs.

The main piece of hardware missing for a practical robot is a sense of touch and sophisticated arms and hands to do things.
-- John
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JGCASEY wrote:

Produce a PC the size of a pack of cigarettes, and for under $100 *complete*, THEN you have a form factor and price more people will be interested in. The Mini_ITX is still too large. Bigger robots cost more to build. While I have four PCs in my home, each weigh in excess of 15 pounds and need to be plugged into a wall outlet. None can be used for robotics projects without gutting them. Certain people here would be upset if I gutted their PC for my robot project.
My laptop is portable but cost $1,700. I use it for some robotics things, but I'm not going to pay $1,700 for a dedicated robot controller. Even a cheap laptop is $600+.
If you're looking to save money, you might as well pay $300 for a self-contained vision system built on a small $100 robot. That's less than a bare-bones IXT-based robot, without any sensors. If money isn't an issue, then by all means the PC-based robot is a good direction. It is not the answer to everything, however.

Oh? There are freebie libraries that have been available for years for VB5 and VB6 for grabbing bitmap samples out of a Web cam. For .NET users there's a great Sourceforge library that wraps DirectShow functions, No C++ needed, ever. Microsoft still provides the .NET compiler for free, and the 2005 Express versions of C# and VB are still either free, or very cheap.
The Sourceforge project includes examples for grabbing bitmaps; from there you can do lots of image processing without needing anything but .NET. If you want to get fancy, there is sample FREE code on CodeProject and elsewhere on how to write simple filters for edge detection, pixillation, motion detection, and more. SERVO magazine recently ran a series of articles on vision; the woman who wrote the articles provides her code, compiled DLL and source, at no charge. You need only rudimentary programming skills to call a couple of DLLs in VB.
I don't do Linux so I don't know what's available for it. But there are PLENTY of accessible and FREE resources if you're developing for a Microsoft OS, and C++ is not required. Some approaches are harder to program than others, but wonderful things await those who make the effort to better their knowledge.
-- Gordon
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Something like this?
<http://www.gumstix.com/products.html
but maybe that doesn't satisfy the "complete" requirement?
regards, dpa
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dpa wrote:

It doesn't have a USB port, which you need to use most cameras. A client USB port is available as an add-on card, but you need a host port, not client.
Much serious image processing involves floating point math, which the Gumstix doesn't do in HW.
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The following non-x86 boards are NOT recommendations because I've never used them, so you will need to do your own research to see if they are suitable, but they both appear to have USB host:
http://www.embeddedarm.com/epc/ts7250-spec-h.html     ARM based, US$149 according to the website. Complete ARM range at     http://www.embeddedarm.com/epc/prod_SBC.htm .
http://www.acmesystems.it/?id=4     AXIS based, ImageCraft is listed as a US distributor, but I couldn't     find it on the ImageCraft website. The UK distributor lists them at     89.95 UKP excluding VAT (105.69 including VAT).
Simon.
--
Simon Clubley, clubley@remove_me.eisner.decus.org-Earth.UFP
If Google's motto is "do no wrong", then how did we get Google Groups 2 ?
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dpa wrote:

Truthfully Gumstix comes pretty close, at least on the size issue. Once you get all the expansion boards for Ethernet etc. it's up to the $200 or so level, but it's still pretty good.
Funnily enough, it won't be robotics that will push smaller/cheaper CPUs, but the growing trend to carputers. Right now it's a cottage industry, but it's growing fast. Geek My Ride is becoming a huge business. Rather than a market of tens of thousands (a *good* day for robotics), it's a market of millions, just for the US. If just 10% of the cars in California had a carputer, we're talking something like two and a half million units.
All running off 12 volt DC, and all in a form-factor of no more than a car radio.
-- Gordon
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