Capture image at 1000 meters/min
Capture image at 1000 meters/min
Author
Discussion

Glade

Original Poster:

4,516 posts

254 months

Thursday 20th December 2007
quotequote all
I have an industrial application where i need to capture a sharp image at up to 1000 meters per minute.

Think it's possible??

Seconds / mm travelled
0.1 / 1666.66667
0.01 / 166.66667
0.001 / 16.66667
0.0001 / 1.66667
0.00001 / 0.16667
0.000001 / 0.01667
0.0000001 / 0.00167


Edited by Glade on Thursday 20th December 09:14


Edited by Glade on Thursday 20th December 14:25

CVP

2,799 posts

306 months

Thursday 20th December 2007
quotequote all
I think (Ok am speculating but what the hay) you can achieve the same effect as a massively short shutter speed with flash.

So shutter speed of 1/250th second but lit with flash, the flash is not going to last 1/250th but is more in the 1/4000th range. If the flash is the primary source of illumination then this will be all that is recorded and hence you get a sharp image. I recall this is how they do the bullet through a balloon type of image.

What you need to work out is;
a) the flash power that will give you the length of time of illumination you need,a nd
b) how the smeg you are going to fire that at the absolute instant to get the image framed correctly smile

I suspect you'll have to go with a darkened room, shutter open and then a carrying device cutting a laser beam and hence triggering your flash but am sure it will take some experimentation to work out exactly where the beam needs to be so that when the flash fires all is correctly aligned.

Cheers

Chris

DIW35

4,205 posts

231 months

Thursday 20th December 2007
quotequote all
Or you could try panning! getmecoat

TheStoat

1,498 posts

252 months

Thursday 20th December 2007
quotequote all
DIW35 said:
Or you could try panning! getmecoat
hehe I'm sorry but that was class!


ETA: I take it this isn't a piece of industrial plant that spins up less than instantly? I.e. you can't shoot as the machinery gets into its stride and is running at lower speeds? Other than that I've got no clue how to do this...

Edited by TheStoat on Thursday 20th December 11:25

dcw@pr

3,516 posts

274 months

Thursday 20th December 2007
quotequote all
Depends how far away it is. Easy to take a sharp picture of a comet and that is moving much faster. Much more difficult to take a macro picture of a dog walking past you at 2kph.

Glade

Original Poster:

4,516 posts

254 months

Thursday 20th December 2007
quotequote all
Let me give more details of the application:

Wire is being manufactured on a production line. in this project sizes 0.5 to 10mm diameters. Currently gross faults are detected with laser gauges. Lumps and Necks in the insulation.

We currently cannot detect defects such as surface roughness when the machine is running. If we run too fast the surface of the wire can be "as rough as a bear's nether reigons" (to quote some official documentation we have here).

There are methods of shining laser or light at a surface and dtermining the surface roughness by analysing the light reflected back.

I want to develop a non contact method for wire at 1000mpm, but if cameras can't get a good image at that speed we might be buggered before we start.

sdws

50 posts

235 months

Thursday 20th December 2007
quotequote all
The only thing I can think of that may be of use is ultra high speed cine as used at MIRA, weapons establishments and other places where bits of kit exploding are recorded.

TheStoat

1,498 posts

252 months

Thursday 20th December 2007
quotequote all
Yep, the equipment for high speed film will easily cope with this particular speed but it costs a bit for the initial camera and the film stacks up very quickly as you'd imagine. I'd want to see example film too, just to make sure the achievable quality provides sufficiently sharp images to examine the wire's surface. I've no idea of the running costs of such equipment though, maybe someone else here has prior experience because that could be prohibitively high to start with?

As a super lazy Google example here's a datasheet for a US-based offering that looks fit to rig up and use remotely (no price mentioned though) http://www.fastecimaging.com/pdf/PDF/Fastec_InLine... These guys have stuff going up to 16K frames per second (obviously dependant on proper lighting)...

ThatPhilBrettGuy

11,810 posts

271 months

Thursday 20th December 2007
quotequote all
Assuming you can get a good image, is it a human or machine analysing the result?

Ledaig

1,810 posts

293 months

Thursday 20th December 2007
quotequote all
A flash based system can, as has been demonstrated on many occasions, capture a clear clean image of a bullet in flight. 1000meter/min is only 37mph so we're not talking extremes. Provided you can set up a point on the production line where ambient light can be kept to a miniumum (or preferably excluded), I believe a flash based system would work to an acceptable level when combined with a decent resolution/quality digi cam.

You need to remember that with such a system it is the duration of the flash which dictates the image - not the shutter speed, hence the need to keep other light out!.

Failing that, have you tried accoustics - I'd lay money on there being something to listen to as the wire is manufactured which can be directly related to the surface finish. This in turn can be hooked up to an alert system.

Glade

Original Poster:

4,516 posts

254 months

Thursday 20th December 2007
quotequote all
Analysed by Machine.

THis needs to be a live system, though refresh rate doesn't need to be high for this application e.g. capture image and check for fault every 10 seconds. (our laser gauges scan constantly for discrete faults, this type of fault would be continuous through the length of the wire)

An image is taken by camera or sensor, computer analyses image and quantifys surface roughness by some method, it then makes a go/no-go decision and outputs a signal to Computer Aided Manufacture system. If there is a defect the operator is alerted so he can take action. Benefit is we can push to run as fast as possible without faults.

I have found papers online for this reflected light method for flat surfaces, its could be another issue making it work on a curved surface. And wether you could calibrate a strobe to freeze the image and act as the correct light source.

Its interesting that its the flash speed that governs the image not the shutter speed. Let me check my understanding... the light freezes the image and thats all that gets recorded. hence no ambient light because that would reflect off the object and be recorded for the whole duration that the shutter is open and give ablurred image. (we actually use strobes to check inkjet marks at high speed)

Edited by Glade on Thursday 20th December 13:26

CVP

2,799 posts

306 months

Thursday 20th December 2007
quotequote all
How do other wire manufacturers measure / QC their output ? DO they use the kind of system you are talking about or do they simply run a batch of wire and hope all is OK?

As I thought and forgive me if you have already thought of this or if I'm heading off down a dead end (I'm not a manufacturing expert smile).

It sounds like the capital set up cost could be large, maybe a different way of coping would be to run a number of tests to determine at what speed the deformation in the surface layer happens and then run your machines at a bit under that speed, say at 90-95%. Whilst you might not be as efficient as possible in terms of speed and you will ahve the occasional batch that goes to waste you do save yourself the capital set up and constant monitoring costs going forward.

Chris

GreenV8S

31,027 posts

315 months

Thursday 20th December 2007
quotequote all
Do you need to see the whole length of wire, or is it enough just to take samples? If it's just samples you need, the idea of panning it might be worth another look. I'm thinking in terms of a spinning mirror synced with the shutter with some post-processing to correct for the distortion.

Glade

Original Poster:

4,516 posts

254 months

Thursday 20th December 2007
quotequote all
CVP said:
How do other wire manufacturers measure / QC their output ? DO they use the kind of system you are talking about or do they simply run a batch of wire and hope all is OK?

As I thought and forgive me if you have already thought of this or if I'm heading off down a dead end (I'm not a manufacturing expert smile).

It sounds like the capital set up cost could be large, maybe a different way of coping would be to run a number of tests to determine at what speed the deformation in the surface layer happens and then run your machines at a bit under that speed, say at 90-95%. Whilst you might not be as efficient as possible in terms of speed and you will ahve the occasional batch that goes to waste you do save yourself the capital set up and constant monitoring costs going forward.

Chris
I don't know if anyone else actually checks for surface roughness in-line and i can only find commercially availible vision systems that look for defects by knowing where and what to look for - some are very advanced but don't do this particular job! I have also found shutter speed in microseconds but having no experience with vision systems so far can't tell if this is up to the job.

We currently feel the wire to check for surface finish but this is frankly a crap method. Operators tend to slow the line down just to be on the safe side, because they'll get a bollocking if they run 40km of rough wire. However to get cost down we need to run as fast as possible!!

What you have described, running at 90% is basically what we do now... but of course Its not quite as easy as setting a max speed and then running just below: variation in matieral, tooling etc means that one day it will run fine at high speed with high pressures and the next it won't... the REAL solution is to get all the inputs to the process under control and the output will be fine, unfortunately its not as easy as it sounds. The sceince of mixing the polymer when it is manufactured and the properties we give it in the barrel are very complex.

Because of the wide range of application for a non-contact, high speed surface roughness detection system in our factories worldwide there is a pot of money there to develop the technology. Its an interesting project!


Glade

Original Poster:

4,516 posts

254 months

Thursday 20th December 2007
quotequote all
GreenV8S said:
Do you need to see the whole length of wire, or is it enough just to take samples? If it's just samples you need, the idea of panning it might be worth another look. I'm thinking in terms of a spinning mirror synced with the shutter with some post-processing to correct for the distortion.
Yeah just samples. We don't need 100% inspection.

Mirrors, might be getting a bit too complex! But i'll look into it.

I think We'll have to work on the calculation for analysing a standard image before we go that far!

CVP

2,799 posts

306 months

Thursday 20th December 2007
quotequote all
Glade said:
I don't know if anyone else actually checks for surface roughness in-line and i can only find commercially availible vision systems that look for defects by knowing where and what to look for - some are very advanced but don't do this particular job! I have also found shutter speed in microseconds but having no experience with vision systems so far can't tell if this is up to the job.

We currently feel the wire to check for surface finish but this is frankly a crap method. Operators tend to slow the line down just to be on the safe side, because they'll get a bollocking if they run 40km of rough wire. However to get cost down we need to run as fast as possible!!

What you have described, running at 90% is basically what we do now... but of course Its not quite as easy as setting a max speed and then running just below: variation in matieral, tooling etc means that one day it will run fine at high speed with high pressures and the next it won't... the REAL solution is to get all the inputs to the process under control and the output will be fine, unfortunately its not as easy as it sounds. The sceince of mixing the polymer when it is manufactured and the properties we give it in the barrel are very complex.

Because of the wide range of application for a non-contact, high speed surface roughness detection system in our factories worldwide there is a pot of money there to develop the technology. Its an interesting project!
Good points, the science of manufacturing is so complex. I think you're absolutely right, getting the inputs right is the key to sorting out your issues. I hate to say this but it sounds like it's ripe for a Six Sigma type approach on the input side of your process. Yes I'm sure you'll need a detection system that detects errors when they happen i.e. rough wire is being produced but that is after the fact, get the inputs right an your error rate goes right down to start with.

Maybe instead of an optical system for QC for the output you could use some kind of pressure test for a device sitting on the wire as it comes out of the production process. A kind of mechanical substitute for the operators fingers. This could detect any roughness in the wire being produced. I would have thought this might be an easier approach.

Chris




Glade

Original Poster:

4,516 posts

254 months

Thursday 20th December 2007
quotequote all
CVP said:
Glade said:
...
Good points, the science of manufacturing is so complex. I think you're absolutely right, getting the inputs right is the key to sorting out your issues. I hate to say this but it sounds like it's ripe for a Six Sigma type approach on the input side of your process. Yes I'm sure you'll need a detection system that detects errors when they happen i.e. rough wire is being produced but that is after the fact, get the inputs right an your error rate goes right down to start with.

Maybe instead of an optical system for QC for the output you could use some kind of pressure test for a device sitting on the wire as it comes out of the production process. A kind of mechanical substitute for the operators fingers. This could detect any roughness in the wire being produced. I would have thought this might be an easier approach.

Chris
Six Sigma is good for this type of problem, however there are so many CRITICAL inputs to this particular process,that putting measures in to control them all is a nightmare! In another project I took 200 inputs down to 45, then tried to contol as many as possible and eliminated correlated factors. Did a DOE on 6 inputs and established a relationship and found that a large proportion of the variation was still unaccounted for by the factors that the team had selected. I don't fancy doing a DOE on 20+ factors it would be mental!!

I used to press metal parts and assemble them, thats EASY compared to getting a highly filled polymer compound mixed and uniform, then spreading it in a very thin layer and ensure that it passes Mil spec and space agency testing!!

CVP

2,799 posts

306 months

Thursday 20th December 2007
quotequote all
All too true - I don't envy you trying to get this sorted.

just pass me a spreadsheet and a business proposal - much much easier smile

Chris

VxDuncan

2,850 posts

265 months

Thursday 20th December 2007
quotequote all
Interesting project! Can't help but think that the biggest issue in an optical system is the image processing required (having worked with a load of image processing spods for the last decade!). You will help yourself considerably by lighting the cable properly to highlight any imperfections (ie cross lighting to put shadows into any depressions in the surface). Or could you pigment the other suraface so differences in colour would easily picked up?

Can help but think there must be an easier way though. Maybe pass an HT voltage through the cable and measure any leakage (or change in resistance) to a cathode somewhere down the line. Or maybe a system that induces a current in the cable (it is moving after all)and looks for any fluctuations in the inductance of the cable (thickness of insulation). Failing that the accustic system seems good - a similar approach is used for robot end effectors (hands). Basically a high sensitivity microphone is built into the grip of the finger to listen for the sound of the object slipping. A similar (contact based) system could be wrapped round the cable, with the added advantage is that you could listen for the specific frequency relating to the speed of flow.

Will keep thinking...

viggen114

259 posts

284 months

Thursday 20th December 2007
quotequote all
There was a doctorate thesis written by someone I knew at Cardiff Uni, not even sure if he finished it because he got to caught up in trying to make a business of it.
He's what i remember, its a few years back, not more than 5.

The task was to inspect rubber grommets during manufacture for imperfections, as they were spun off the moulds, which ran at some incredible speed, he had a LED source which flickered at some rate or other and then detectors picked up the reflections, analysis was made on the results by microprocessor, the turnout rate was huge.
Nigel, last time I saw him was working for a company in the Bristol area, who bought him and his system.
If this of use I'll try to remember more.