Need engineer for hire

Is, say, $40,000 in moderate production quantities "low cost"?

And what would you bolt it to? A few cubic yards of nice reinforced concrete might be a start. Slewing 11 pounds at 20 RPM to 13 arc-seconds accuracy will get interesting; bedrock footings, maybe.

John

Do you need to move the camera in azimuth or just pan? Can you put a small mirror in front of the camera and move just that (leaving the camera stationary)?

What sort of resolution must the final image have? One approach is to put a wide angle lens on the camera, have it look straight up and extract the portion of its image in the direction of interest using software.

--
Paul Hovnanian	paul@hovnanian.com
-----------------------------------------------------------------------
Procrastinators: The leaders for tomorrow.

--
1lb, not 11lb.

--
    

    60°    360°    1rev     10rev     10rev
   ---- = ----- = ------ = ------- = ------- = 10RPM
    1s     6s       6s       60s       1min

Well, it's still a challenge. The reaction forces kicked into the mount will take a long time to settle out; it might settle faster if it slewed slower. Arc-seconds are not "hacker" territory.

John

These guys probably have what you want off the shelf:

I've used their model 20 for several projects (even controlled from an embedded processor) and it is quite straightforward to control. But there is one catch: during calibration it needs to be able to travel freely to all its limits.

--
Reply to nico@nctdevpuntnl (punt=.)
Bedrijven en winkels vindt U op www.adresboekje.nl

And since he prefers 120 degs/sec, 20 rpm is what he wants.

John

I think the answer lies in software - overlap the pictures a bit and stitch them together in post-processing and all of a sudden things become much easier.

Hello Nico,

Do you have an idea how much this one will cost?

Best regards, Helmut

But you guys should be quite versed in dynamic load shifting for earthquake protection. Or is it only Japan that does that?

Other than that just move the installation to the right place, like outside my lab. There is a rock that's huge, where the other end of it seems to crop out in China.

--
Regards, Joerg

http://www.analogconsultants.com/

Yeah, a simple cross-correlation algorithm could fine the ideal shifts to fit frames together, if the timing allows.

John

For "cheap PTZ" (like $100 >100 off) I'd be thinking 2 (good) direct drive steppers with 500 microstep drivers. But, earning a crust is never that easy. I'll bet there's a (unmentioned) zoom lens fitted on the cam, which will scupper the positioning repeatability in accordance with the weight distribution changing with zoom lens position. Need massive motors and drivers, make it $1000 a unit.

Somewhere around 9000 euro if I recall correctly from about two years ago. Asking Sagebrush will give you a more accurate answer. The dollar went down substantially so it may be a lot cheaper now.

--
Reply to nico@nctdevpuntnl (punt=.)
Bedrijven en winkels vindt U op www.adresboekje.nl

Wow lots of responses.

By low cost I'm talking between $1000 and $2000 per head. With a small camera I really don't see the need to go heavy duty mounts - that sagebrush unit is huge and heavy, and probably 10x times what I'm looking at for cost. I'm wondering if it's using stepper's (big & heavy).

There is a zoom lens on the cam, so this is just a Pan-Tilt head but with communications hardware added for the zoom (so it's all on one interface). There are several cameras we are looking at, all at less than 2 lbs and fairly small dimensions.

BB - Yes for the most part the answer is in the software but the higher accuracy the mount is, the less processing needs to take place on the imaging.

Just so we're thinking along the same lines, what we use now are the Sony EVI-D70 and BRC-300.

The BRC-300 has a resolution of 0.0048 degrees but the encoding accuracy is relatively poor, at about 0.1 degrees from what we could estimate. We are looking at developing our own camera (with the camera essentially an OEM zoom camera) and a custom Pan-Tilt head for it. Here's our ideal complete specs:

120 deg/sec movement mount weight: 4-5lbs max. mount dimensions (including camera): 9"H x 8"W x 8"D DC powered: 12-24VDC Payload: 2-3lbs max. Travel Range: -170 to +170 deg pan, 0 to +90 tilt deg tilt (horizon to straight up) Motor Resolution: 0.0036-0.0050 deg resolution (13-18 arcseconds) Control Mechanism: RS422/Ethernet Control Notes: Must be able to address specific pan/tilt locations to move to, much like a targeting system. Must also be able to get a constant readback of current position.

Cost: $1000-$2000 range is ideal. There is some room but the less the better, as we are going to build them in quantity.

Of course, there's some room to move on the speed, and some of the other spec's. We have yet to find anything suitable commercially available, usually this type of accuracy is reserved for much larger units that cost $10k+. It's definately a challenge, but the benefits would also follow :)

Paul - you know I've never even thought of that. Could we just move a mirror instead? Damn that could be a good idea, as long the mirror won't distort the image (HD resolution). Hmm I'm going to have to think about that one, they use the same principle in lighting because of the speeds and weight considerations, I don't see why it wouldnt' work for video :P

--
For whom?

What would you be willing to pay to have a system designed which
would meet all your spec\'s and which you could put together in
production quantities for

I'd be willing to pay what it costs :) Right now I'm trying to get an estimation on who has the capabilities of developing the mount, and a rough estimation on the engineering costs. We would be looking at proceeding with this in January of 2008, as far as a timeline goes. It may even lead to a full-time position if it is desired.

two words: inverse kinematics

could be

Best regards, Spehro Pefhany

--
"it's the network..."                          "The Journey is the reward"
speff@interlog.com             Info for manufacturers: http://www.trexon.com
Embedded software/hardware/analog  Info for designers:  http://www.speff.com

Hmm I'm thinking the only way to get the range using a mirror would require that it was curved, and that would reduce the resolution of the perceived image because of the super wide view. Unless I'm missing something.