Need engineer for hire

[Michael Brown]

Hey all... I figured this was a good place to start.

I'm looking for someone who can take on a project for my company, to
design a very accurate PTZ mount for a small camera. The mount will
need to have a resolution of around 100,000 steps (0.0036 degrees per
step), and high accuracy positioning (repeatably it should go to the
same exact spot when it's told to via serial/network communication
interface). The camera weight will be around 1lb, so it doesn't have
to be too heavy duty. It also needs to maintain a minimum speed of 60
deg/s for movement (ideal is 100-120 deg/s).

Anyone interested in a project like this? I can provide more details
to those interested in the project. It needs to be developed as a low
cost mount, I can elaborate on what low cost means in an email.


Anyways, thanks guys - looking forward to hearing from some talented
hackers

 

[John Larkin]

Hey all... I figured this was a good place to start.

I'm looking for someone who can take on a project for my company, to
design a very accurate PTZ mount for a small camera. The mount will
need to have a resolution of around 100,000 steps (0.0036 degrees per
step), and high accuracy positioning (repeatably it should go to the
same exact spot when it's told to via serial/network communication
interface). The camera weight will be around 1lb, so it doesn't have
to be too heavy duty. It also needs to maintain a minimum speed of 60
deg/s for movement (ideal is 100-120 deg/s).

Anyone interested in a project like this? I can provide more details
to those interested in the project. It needs to be developed as a low
cost mount, I can elaborate on what low cost means in an email.

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

 

[Paul Hovnanian P.E.]

Hey all... I figured this was a good place to start.

I'm looking for someone who can take on a project for my company, to
design a very accurate PTZ mount for a small camera. The mount will
need to have a resolution of around 100,000 steps (0.0036 degrees per
step), and high accuracy positioning (repeatably it should go to the
same exact spot when it's told to via serial/network communication
interface). The camera weight will be around 1lb, so it doesn't have
to be too heavy duty. It also needs to maintain a minimum speed of 60
deg/s for movement (ideal is 100-120 deg/s).

Anyone interested in a project like this? I can provide more details
to those interested in the project. It needs to be developed as a low
cost mount, I can elaborate on what low cost means in an email.

Anyways, thanks guys - looking forward to hearing from some talented
hackers

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.

 

[John Fields]

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 Fields]

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.

---


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

 

[John Larkin]

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

 

[Nico Coesel]

Hey all... I figured this was a good place to start.

I'm looking for someone who can take on a project for my company, to
design a very accurate PTZ mount for a small camera. The mount will
need to have a resolution of around 100,000 steps (0.0036 degrees per
step), and high accuracy positioning (repeatably it should go to the
same exact spot when it's told to via serial/network communication
interface). The camera weight will be around 1lb, so it doesn't have
to be too heavy duty. It also needs to maintain a minimum speed of 60
deg/s for movement (ideal is 100-120 deg/s).

These guys probably have what you want off the shelf:

www.sagebrushtech.com

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.

 

[John Larkin]

---


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

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

John

 

[BB]

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.

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.

 

[Helmut Sennewald]

These guys probably have what you want off the shelf:

www.sagebrushtech.com

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.

Hello Nico,

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

http://www.sagebrushtech.com/downloads/datasheets/model20servo_datasheet.pdf

Best regards,
Helmut

 

[Joerg]

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.

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.

 

[John Larkin]

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.

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

John

 

[john jardine]

Hey all... I figured this was a good place to start.

I'm looking for someone who can take on a project for my company, to
design a very accurate PTZ mount for a small camera. The mount will
need to have a resolution of around 100,000 steps (0.0036 degrees per
step), and high accuracy positioning (repeatably it should go to the
same exact spot when it's told to via serial/network communication
interface). The camera weight will be around 1lb, so it doesn't have
to be too heavy duty. It also needs to maintain a minimum speed of 60
deg/s for movement (ideal is 100-120 deg/s).

Anyone interested in a project like this? I can provide more details
to those interested in the project. It needs to be developed as a low
cost mount, I can elaborate on what low cost means in an email.


Anyways, thanks guys - looking forward to hearing from some talented
hackers

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.

 

[Nico Coesel]

Hello Nico,

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

http://www.sagebrushtech.com/downloads/datasheets/model20servo_datasheet.pdf

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.

 

[Michael Brown]

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.

 

[Michael Brown]

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

 

[John Fields]

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

---
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 <= USD 2k?

 

[Michael Brown]

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.

 

[Spehro Pefhany]

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.

two words: inverse kinematics

Need massive motors and drivers, make it $1000 a unit.

could be


Best regards,
Spehro Pefhany

 

[Michael Brown]

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

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.