Author Topic: Seek Thermal: Hardware modifications to improve image quality (Read 46538 times)

frenky · « **on:** January 10, 2016, 10:36:13 pm »

I have found out that i3 ThemalExpert won't be priced at 500$ but at 820$. (At this time I can't reveal the source or any more details...)

That price is a deal breaker for me so I decided to make some extensive modification to my SeekThemal module to improve it as much as possible.

The first mod will be to make a external shutter from a regular pcb. I will paint the copper side with matte black, since that worked good for me in the past.
And the second mod will be cooling the back of the sensor with the Peltier module. (I might even cut pcb in half to cool only the sensor part, but that is risky.)

Both mods should show a significant impact on the image quality.

External shutter should provide a much better isothermal plane so when we subtract pixel values we should get much cleaner image.
And the cooling of the sensor should prevent pixels from drifting too much.

The mechanism for shutter will look something like this:

Animation:

My progress so far:
I took a cheap solenoid, removed the core pin, and glued the magnet in the ink cartridge of a pen:

This is working good; when I apply voltage (5V) the cartridge with a magnet ejects out of a solenoid.

Next step is to glue on a pcb painted matte black...

P.S.:
Big thanks to Dave for giving us a subforum where we can share knowledge and help each other.

frenky · « **Reply #1 on:** January 11, 2016, 09:52:18 pm »

It's not pretty but it works.

miguelvp · « **Reply #2 on:** January 12, 2016, 05:45:37 am »

Nice

frenky · « **Reply #3 on:** January 12, 2016, 08:08:25 am »

Tnx.
It's a lot of fun making something mechanical since I mostly work with software...

frenky · « **Reply #4 on:** January 19, 2016, 11:34:32 am »

This one did not work well, because friction between bearings and shaft is to big, but I thought I'd show it any way.

(I did lubricate it with lithium grease but it did not help.)

Fraser · « **Reply #5 on:** January 19, 2016, 10:42:43 pm »

Hi,

Whilst I appreciate what you are trying to do. Your current solution is somewhat different to the approach taken by the thermal camera industry. That is not to say your design will not work..... but most FFC shutter designs have low thermal and physical mass. That way they do a good job whilst requiring a light duty, low current actuator.

May I suggest you take a look at commercial actuators for a filter or lens as used in some CCTV cameras. Such actuators insert and remove the IR filter for day/night cameras.

I have seen these IR filter actuators on eBay and they are very cheap as they are designed for PCB cameras. You can even buy a complete Day/Night PCB camera and extract the actuator assembly. Then you just need to replace the IR filter with a suitable material for an FFC shutter flag.

I will add some links to the filter actuators shortly.

Fraser

Fraser · « **Reply #6 on:** January 19, 2016, 11:05:21 pm »

Here you go.... cheap as chips and a neat design.

http://www.ebay.co.uk/itm/171912913239?_trksid=p2060353.m1438.l2649&var=470829576710&ssPageName=STRK%3AMEBIDX%3AIT

http://www.ebay.co.uk/itm/401003344143?_trksid=p2060353.m1438.l2649&ssPageName=STRK%3AMEBIDX%3AIT

http://www.ebay.co.uk/itm/321492559019?_trksid=p2060353.m1438.l2649&ssPageName=STRK%3AMEBIDX%3AIT

http://www.ebay.co.uk/itm/262234538296?_trksid=p2060353.m1438.l2649&ssPageName=STRK%3AMEBIDX%3AIT

http://www.ebay.co.uk/itm/262234538299?_trksid=p2060353.m1438.l2649&ssPageName=STRK%3AMEBIDX%3AIT

You could probably get away with just spraying the glas IR filter with matt black paint, so no need to fit an IR opaque flag.

frenky · « **Reply #7 on:** January 20, 2016, 09:59:07 am »

Big thanks for this.

I think you are the top expert on this forum when it comes to thermal cameras inner workings so I really appreciate your input.

So does this actuators work like solenoid? While coil is energised the shutter is in position 1 and when you cut the power it goes to position 2?
Or it's more like latching relay? On every pulse it will toggle position?

The price is right

so I will order some from china, but continue working on my own design so I have more options...

Fraser · « **Reply #8 on:** January 20, 2016, 11:04:52 am »

Hi Frenky,

The filter actuators can be either a toggle action or momentary, depending upon the particular design. It may be worth asking the seller before buying. Even if a toggle action, these units can usually be dismantled for modification. I regret I have no more data on the actuators.

They are certainly cheap enough for some experimentation.

Something to also consider when building an FFC shutter is any vibration caused by the actuator mechanism. The CCTV actuators cause little or no vibration when they operate.

Fraser

frenky · « **Reply #9 on:** January 20, 2016, 11:50:20 am »

Tnx for the info. I'll do a video of received actuators when they arrive.

frenky · « **Reply #10 on:** February 03, 2016, 08:12:00 pm »

Today I got the actuators. I tried connecting the first to 5V and nothing happened... Then to 10V nothing... 20V, 30V, 40V, and then it started to smell...

Went back to 5V and swapped the leads (red to - and black to +) and "click" it changed the filter. Swapped leads again and "click".
So every time you want to switch filters you must change the voltage polarity.

The smallest actuator is just perfect for Seek. I will be swapping its filter for a painted copper/alu plate in the near future.

P.S.
Fraser big thanks for pointing me into this direction.

Fraser · « **Reply #11 on:** February 03, 2016, 08:39:45 pm »

It was a pleasure to help.

As the flag is at ambient temperature you might not need to remove the filter. Just paint it.

Do all do the actuators toggle on supply polarity ? Maybe the flag mechanism can be modified ?

Looking forward to further updates on your project.

Fraser

frenky · « **Reply #12 on:** February 03, 2016, 08:40:29 pm »

Mechanism can slide out of the bulk housing so the module is even more compact.

Internals of one of the other actuators:

EDIT: Yes all actuators need polarity swap to change filter.

Fraser · « **Reply #13 on:** February 03, 2016, 08:50:36 pm »

Thanks for the pictures.

If you add s small tension Spring you can hold the flag in one position with a single polarity pulling the flag into its second position. If there is a friction plate or 'bump' to provide a 'hold' in each position, remove it so that the flag can mode from one position to another easily.

The alternative would be an electronic toggle drive circuit but I prefer the hardware route myself. The only part to source would be a very light tension Spring.

Fraser

frenky · « **Reply #14 on:** February 03, 2016, 09:08:44 pm »

Tnx. I might try it in two different ways.

1. Add a spring to make it go back to the first position when the power is cut. Just like you suggested.
Then remove internal shutter and solder its wires to this new shutter.
If the resistance of internal coil is much higher then use transistor or mosfet to drive external coil. (So that I don't damage the circuit...)

2. Leave internals of the Seek intact and do the magic with the software (I prefer that).
The sequence of frames is like this: precalibration frame, calibration frame (image of the internal shutter), first thermal frame, second thermal frame...

When the pre-calibration frame shows up I would send signal trough serial port to attiny to close the external shutter.
Then keep it closed until the calibration frame and the first thermal frame are saved. Then send command to open external shutter.
This way I can decide on the fly if I want to use captured image frame as an external reference or just use calibration frame of the internal shutter.
Or even use both combined in some weird way.

frenky · « **Reply #15 on:** February 05, 2016, 09:31:03 pm »

Two actuators connected to L293D and arduino...

Fraser · « **Reply #16 on:** February 05, 2016, 10:00:35 pm »

Looking good. Nice snappy action on the actuators.

Fraser

frenky · « **Reply #17 on:** February 22, 2016, 11:57:16 am »

Good news... I've connected SeekThermal to RPI2 loaded with Win 10 IoT core and out of the box it it recognizances it as "PIR206 Thermal Camera".
I believe this is a very good sign for putting existing SeekOFix code on RPI:

I a few months:

miguelvp · « **Reply #18 on:** February 22, 2016, 03:16:41 pm »

That's pretty cool, or hot depends on how you seek it

For one thing, it kind of shows that Win10 IoT is a viable solution for some applications on a small form factor.
And another thing it shows that you rock!

frenky · « **Reply #19 on:** February 23, 2016, 06:57:29 pm »

Tnx for nice words.

Today I've put together a quick & ugly setup for external shutter just to see if it works.
From the code I send command via serial port to arduino to close or open shutter with L293D. I close it when frame ID1 comes and open it after first ID3.
I also made a few changes in code to always use external calibration from first frame ID3.

Setup:

Image of the reflectors (flood light) on the ceiling with internal shutter calibration:

And with external shutter:

As you can see there is less noise and better real temperature representation.
While Seek did sort-of fix that gradient it still shows up at low temp span. (Clearly visible on the first image bottom-right)

frenky · « **Reply #20 on:** February 28, 2016, 05:27:44 pm »

I'm not 100% sure what is going on but now I'm getting a lot cleaner images (with external shutter):

This was the image from few days ago:

And this is from today:

Most likely the temperature of the sensor influences the quality of the thermal images. I will test this by saving every 20th frame for a half an hour.

Fraser · « **Reply #21 on:** February 28, 2016, 05:36:09 pm »

Indeed, a significant reduction in the noise content. Had my SEEK produced such pictures I would have been more than happy with it.

Fraser

frenky · « **Reply #22 on:** February 28, 2016, 05:42:04 pm »

True...
This observation gives me hope that when I'll stick Peltier element on the back of the Seek the images will be low noise all the time.

Fraser · « **Reply #23 on:** February 28, 2016, 08:19:16 pm »

Hmmmmm, I presume you intend to stabilise the microbolometer at 30C and not try to cool it to a low temperature ? The designer will have intended the calibration tables to be valid at and around 30C, not at a low temperature of say 10C. You could try it but you may have issues with calibration and NUC. The FLIR E4 is only 'happy' once it's die temperature monitoring sensors indicate around 30C. It becomes less accurate as the die temperature moves away from that calibration temperature. My PM series cameras are Peltier element temperature stabilised at 30C.

As for why a microbolometer would be noisy at one temperature, and less so at another similar temperature, I cannot say. Microbolometers are, after all, just an array of VOX thermistors. Sure the VOX thermistor will have its own thermal noise but I would expect significant levels of cooling to reduce this significantly. FLIR have spent a lot of time improving the design of their microbolometers, and the processing software, in order to reduce noise. If cooling the microbolometer had a significant effect on the noise levels I would have expected them to cool the microbolometer long ago. Even my PM695 has a temperature stabilisation Peltier element producing 30C at the die. The SEEK camera may have thermal issues however, such as an ROIC that produces noise that varies with temperature ?

Certainly worth investigating but I suggest you do not spend to much money on this avenue of investigation.

I am suspicious of the read out electronics and software processing in the SEEK. I can offer no explanation for why you suddenly had a decent lower noise image on your unit. Very interesting though.

Fraser

Fraser · « **Reply #24 on:** February 28, 2016, 08:26:09 pm »

I just had a thought.........

The microbolometer is an analogue device and it is essential that it, and the ADC has a nice clean power supply. The SEEK is a very compact device built with the minimum of components to maintain a low BoM. It would be well worth looking very carefully at the quality of the supply rails that are feeding the analogue sections of the camera. Any noise on these will be digitised and become part of the image. Unlike a boost converter frequency breakthrough which would likely produce banding, look for random noise. Such would be superimposed on the microbolometer data as random image noise. I can believe that such noise could vary with temperature or even the source of power for the camera.

Fraser

frenky · « **Reply #25 on:** February 29, 2016, 11:06:12 am »

Tnx for your input. You gave me a lot to think about and to try out.

frenky · « **Reply #26 on:** May 22, 2016, 08:37:14 pm »

Today I had some time to try the effect of Peltier element strapped to the back of the seek.
I polished the back of the seek to expose bare metal (magnesium alloy) for better contact. And I also opened it and stuffed 3 layer of thermal pads between the pcb and the housing.
All with the idea of cooling down the sensor and the shutter.

Peltier is TEC1-12706 (12V 60W). I was running it at 0.5A 2V (1W).

Seek + peltier + big heatsink:

Image of room corner (5*C temp diff) without peltier:

Image with peltier on:

As you can see the difference is huge. No wonder that old TI all had some sort of cooling system...

Just for fun 20 images stacked with ImageMagick "convert *.png -evaluate-sequence median OUT.png":

I'm pretty happy with the result.

tomas123 · « **Reply #27 on:** May 22, 2016, 09:00:30 pm »

great

or better: cool

which temperature do you reach with the Peltier element?

frenky · « **Reply #28 on:** May 22, 2016, 09:07:33 pm »

According to this document http://www.hebeiltd.com.cn/peltier.datasheet/TEC1-12706.pdf I could push it to -41*C.

Well I did not measure the temperature during the test but I did found out that even if I went to 1A with current the image did not get better (I think it was even worse).
I'll repeat the test soon...

Fraser · « **Reply #29 on:** May 22, 2016, 09:56:12 pm »

There is an issue with this type of cooling....... condensation. You need to be careful about condensation on the SEEK camera's PCB.

Well done for doing this test though. As you say, cooling lowers noise in many electronics systems that deal with very small signal levels. The Agema Thermacam 400 runs the detector at -70C.

Fraser

frenky · « **Reply #30 on:** May 23, 2016, 06:47:46 am »

I was thinking about condensation before experiment. My plan was not to go below 10*C, because that is dew point in my room (40% humidity, 25*C).

But when I started getting nice images I kind of forgot about it.

I guess condensation is one of the reasons that some actively cooled sensors are in vacuum?

Hopefully condensation did not occur on sensor of my seek I'll make sure that I don't go below 10*C in the future tests...

I'll also try to find the highest (actively cooled) temperature that still improves seeks images...

joe-c · « **Reply #31 on:** May 26, 2016, 09:48:39 pm »

the Stacked image looks nearly the E4+ Images.
Really cool

the "evaluate-sequence median" means Average right?

frenky · « **Reply #32 on:** May 26, 2016, 10:01:33 pm »

Yes kind of. If you have values 0,0,9,9,12 the average is 30/5=6. But median is 9 which is much better for noise reduction.

frenky · « **Reply #33 on:** July 06, 2016, 10:10:47 pm »

It seems that I may have destroyed my seek... $:-\$

The last thing I did was test the fit of custom made copper radiator that wold go on the back of the pcb...
Today I turned it on and the screen is solid orange with 300*C in the middle. I have no idea what happened to it...

I am really disappointed that I didn't get to try out my new setup with Peltier module and custom heatsink that fits pcb perfectly... and moved internal shutter in front of lens...

frenky · « **Reply #34 on:** July 09, 2016, 08:04:03 am »

I'm one happy hippo.

So what was the problem...
During my tests I have removed the internal shutter and I was shure that this will just distort output images a little as seen in Mike's video.
But during the power on the seek takes basic calibration frame with shutter covered. And without shutter this frame had really high values and software then pushed all real values to the 300*C.
Now I covered the lens and the shutter hole during the startup and the Seek works just fine. Image is distorted because there is no shutter to calibrate it abut it works!

I'm so happy.

Fraser · « **Reply #35 on:** July 09, 2016, 10:35:36 am »

Excellent news Frenky

Fraser

IwuzBornanerd · « **Reply #36 on:** August 13, 2016, 06:09:57 am »

Has anyone who has cracked one of these Seek cameras open tried to find a way to reduce the random noise in the image via hardware changes such as better bypassing, rounding clock signals or anything like that? There are noise patterns also, but lots of seemingly random crap, and maybe some "rolling through" noise.

frenky · « **Reply #37 on:** August 13, 2016, 09:24:59 am »

On my to-do list was removal of R1 resistor and injecting 5V from 4xAA batteries to input of U1 regulator which supplies 2.8V to sensor.
This should remove most of the powerline noise...

EDIT: Perhaps you coluld even bypass U1 with two NiMh accus charged to 1.4V so you would supply 2.8V directly to sensor...

joe-c · « **Reply #38 on:** August 13, 2016, 09:06:58 pm »

Quote from: frenky on August 13, 2016, 09:24:59 am

This should remove most of the powerline noise...

it sounds really interesting. it would be great if there is a hardware way to reduce the noise.

good luck

frenky · « **Reply #39 on:** August 13, 2016, 09:14:00 pm »

There is. Just strap a peltier module to the back of the seek and cool it to 15*C...
https://www.eevblog.com/forum/thermal-imaging/seek-thermal-hardware-modification-to-improve-image-quality/msg946675/#msg946675

joe-c · « **Reply #40 on:** August 13, 2016, 09:30:51 pm »

Quote from: frenky on August 13, 2016, 09:14:00 pm

There is. Just strap a peltier module to the back of the seek and cool it to 15*C...

yes, i saw this images some weeks ago.

Maybe i should assemble the Board on a small Tec, and build a housing with a thermal Window and than use a vacuum pump to remove as much air as possible from inside...
i should go to bed, i am tired and have crazy ideas $:=\$

frenky · « **Reply #41 on:** February 13, 2017, 09:18:21 am »

Good news (at least for me)...

I had some spare time yesterday and I decided to try and fix my broken SeekThemal module.
A few freeze spray bursts and it came back to life.

It seems that one of the solder joints on flash ic has cracked so I re-flowed four joints and now it's good as new.

So now I can go back to hacking the hell out of it because I don't care if I destroy it since I already have much better module in hand (i3 T.E.+).

Fraser · « **Reply #42 on:** February 13, 2017, 09:30:55 am »

Great news 🙂👍

joe-c · « **Reply #43 on:** February 13, 2017, 08:56:57 pm »

gratz frenky.

I have seen, that the Seek hold the ADC Offsets as long as the device is Powered.
so if you change after warm-up to raw mode, you can use this mode next day if the Seek was just powered over the external Hub, while the PC is down.

If the TE works with the Planck formula, the Seek will be the next

Uho · « **Reply #44 on:** May 31, 2017, 12:34:21 pm »

I did a small upgrade of seek thermal reveal . Added a telephoto lens and eyecup.
https://youtu.be/rt4EHTFfKVw

meanie2 · « **Reply #45 on:** October 07, 2019, 09:46:11 am »

Is anyone else still trying to improve the seek's image output with hardware mods?

Ultrapurple · « **Reply #46 on:** October 07, 2019, 01:22:51 pm »

I'm not sure whether work is still in progress anywhere but it does give interesting food for thought on other TICs. I'm thinking of trying something similar with one of my Therm-App cameras when I have time.

Fraser · « **Reply #47 on:** October 07, 2019, 02:27:45 pm »

If considering using a Peltier cooler on a small thermal camera a convenient TEC controller is the type commonly found cooling tuned Lasers. They are normally very compact and the temperature is set on a multi turn trim pot. Nice and portable

Fraser

IwuzBornanerd · « **Reply #48 on:** October 10, 2019, 10:12:17 am »

If one is stuck using the camera with a stupidphone the benefit of using a cooler will be limited to getting the camera down to the temperature at which Seek created the NUC table. While cooling it down farther might get you less noise you will not likely see the improvement without having a NUC table created at that temperature, and the Seek app does not provide a way to do that.

I do not have any on-going effort to reduce the noise, but I am not done trying. I have tried to figure out what Seek did to reduce the noise from the original atrocious level to it's current level but have had no success there. There is at least one thing I want to try when I get around to it...but those round to-its are hard to come by.

Ultrapurple · « **Reply #49 on:** October 11, 2019, 08:14:23 am »

Quote from: IwuzBornanerd on October 10, 2019, 10:12:17 am

those round to-its are hard to come by.

Nonsense, sir. You're simply spellling it incorrectly.

I simply asked my stupidphone to find me some. Perhaps my strupidphone is more stupid than your stupidphone...?

(quick help-ask: I tried to use the {img=200x200}file_url{/img} construct (but with square brackets of course) to size the above images, but to no avail. Is there a different function I should be using?)

IwuzBornanerd · « **Reply #50 on:** October 11, 2019, 08:52:43 am »

But of course, haven't you seen me say I don't have a stupidphone!?

That one says right on it that they are hard to come by.

'

What it does not say is that they are all designed for one specific purpose so you can't use it for something else.

Ultrapurple · « **Reply #51 on:** October 12, 2019, 11:28:31 am »

Humble apologies about the misunderstanding. I had taking the liberty of presuming that "I don't have a stupidphone" was another take on the "my home computer's BASIC is better than your home computer's BASIC" - ie you choose something you consider to be cultured and sophisticated, like (and here I take the risk of being downright insulting) a Windon't Phone, as opposed to one of the varieties of fruit or mechanoid-themed devices.

I've just phoned out for a pizza with a side-order of humble 3.14159 (or, perhaps, 8.53973422267).

IwuzBornanerd · « **Reply #52 on:** October 12, 2019, 10:12:33 pm »

Oh, gee, no offense at all! I call them "stupid-" instead of "smart-" "just because", for the irony of it I guess. How often do we refer to our computers as "stupid computer"?

I tell people that the PI Zero I mobilized to use for driving a Seek is like a smartphone without the phone, or a "smart". I'd keep the same vernacular & call it a "stupid" but I am too happy with how it worked out to call it stupid.

Cat · « **Reply #53 on:** October 23, 2019, 08:48:45 pm »

Just for documentation the changing image quality when cooling a CompactPro.
Not to be confused, the CompactPro was pointed to a "normal" Seek Compact plugged into a Motorola G5s. The CompactPro is connected to a Sony Z3 with the Seek-App version 2.1.6.

At first the CompactPro was running a few minutes, then the recording was started and the screenshot on the left is showing the image quality. There is no significant change in noise before or after the NUC (or FFC

). Then a small piece of water ice wrapped in a paper towel was put on the case of the CompactPro behind the FPA. The case is slowly cooling down a few degrees and the image quality is changing significantly. Much less noise but only shortly after the NUC (middle screenshot). A few seconds later the noise is even worse than witout cooling until the next NUC.
You can watch the recording in realtime here: https://files.catbox.moe/hcyhro.mp4

When I get a round tuit

I'll put the CompactPro into a climate chamber and check if the noise still changes when having a constant temperature.

My normal Seek Compact does not seem to improve with cooling, at least there is no visible effect.

bap2703 · « **Reply #54 on:** October 24, 2019, 02:36:50 am »

Beware using 'noise' as 'spatial noise'.
To reduce the residual spatial noise you need to stabilize the temperature, not cool without any control.

BUMERANG · « **Reply #55 on:** November 05, 2019, 05:30:26 pm »

Всем доброго времени суток!
Ребята подскажите, умеет ли Seek SHOT PRO снимать макро, к примеру рассматривать с расстояния 5-10см платы например смартфонов ?

IwuzBornanerd · « **Reply #56 on:** November 07, 2019, 10:41:08 am »

Quote from: BUMERANG on November 05, 2019, 05:30:26 pm

Всем доброго времени суток!
Ребята подскажите, умеет ли Seek SHOT PRO снимать макро, к примеру рассматривать с расстояния 5-10см платы например смартфонов ?

Nyet. See the first line from @blueskull here: https://www.eevblog.com/forum/thermal-imaging/thermal-camera-lens-mod/msg2518086/#msg2518086

Seek Shot is "fixed focus" (aka never-focused), so it would need an added external lens such as the ZnSe lenses many people use for that purpose in order to get a closer focus.

And, yes I used Google translate. Ya ne ponimayu russkiy.

nikitasius · « **Reply #57 on:** July 31, 2020, 02:37:41 pm »

Quote from: frenky on February 03, 2016, 08:12:00 pm

Today I got the actuators. I tried connecting the first to 5V and nothing happened... Then to 10V nothing... 20V, 30V, 40V, and then it started to smell...

Went back to 5V and swapped the leads (red to - and black to +) and "click" it changed the filter. Swapped leads again and "click".
So every time you want to switch filters you must change the voltage polarity.

The smallest actuator is just perfect for Seek. I will be swapping its filter for a painted copper/alu plate in the near future.

P.S.
Fraser big thanks for pointing me into this direction.

Hi,
This can be soldered directly to use power contacts from existing shutter? Or seek's voltage is too weak?


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Author Topic: Seek Thermal: Hardware modifications to improve image quality (Read 46538 times)

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