automotive Can I Use a Simple Overlay Graphic for Automotive Tests?

[korn]

Is there a way to overlay a picture file on top of a scope screen?

For example here is screenshot of an in cylinder pressure transducer waveform on an old Mercury..

Using an external graphics program I can overlay the 720 degree scale image

Can I float this picture over the scope scale ?

It would be great If I could resize the picture to fit the pressure peaks and vary its opacity so I wouldn't need the external program steps........

There are other overlays I use but this is the simplest one I have....

I did try the cylinder measurement overlay but it is not good for looking at a single cylinder like this test does. I was able to set it for 4 cylinders and get the cylinder lines to show the 4 strokes but not quite what I am used to......

 

Edited July 17, 2023 by korn

[JColvin]

Hi @korn,

I don't think it's possible to float / overlay an image directly over the plot view quite like you are describing; using Cursors and Labels will get you part way there (looks like you used cursors in your last screenshot; Labels can be added via the Gear icon in the top right of the Plot view). Maybe this would be possible in the future, but I don't know the underlying software well enough to know how much of a change this would need to be to overlap the Notes option with the Plot view (if the WaveForms developer thinks that such a feature is viable).

Otherwise, you can help make the view less cluttered for easier overlay by undocking the window via the icon in the top right and then right-clicking anywhere in the top of the GUI to uncheck/hide whatever toolbars you don't need in the the final image (example screenshot I got while not at the office today):

Let me know if you have any questions.

Thanks,
JColvin

[korn]

Thanks for the suggestions.

I see the automotive measurements were just added in the latest beta so this must be a work in progress.

they report amplitude peak and rpm but the overlays are tied to 720 degrees of crankshaft rotation and the cursor measurements need to read the time domain in degrees not ms as you scan  over the waveform.....

then there is the use case where a sensor is in a shared plenum and the multicolored overlay helps to  visualize all cylinder events.

I think that was where the cylinder measurement was headed....

below is that overlay on this waveform for reference.

the colors represent:

red - power

brown - exhaust

yellow - intake

orange - compression

 

Edited July 18, 2023 by korn

[nurber3]

I was just looking for a similar feature in the manual and think this would be a handy addition to Waveforms.  In Picoscope jargon they call it a reference waveform.  You just identify a capture as a reference and the software identifies it as a regular channel with an appended number.  Last I used this feature Picoscope didn't provide transparency which I see Waveforms has and I think would be useful to accentuate capture over reference.  I'd always wished Picoscope would have a cloud service for upload & download of reference waveforms ( with powerful search capabilities ).  Picoscope provides but only for automotive which always seems to deny others from interesting collaboration.  Linked video intro to waveform library including reference.

[attila]

Hi @korn

 

[attila]

Hi @nurber3

In WaveForms you can save/load workspaces and projects, import/export captures (multiple channels into a tab) and add/import/export reference channels.

[korn]

6 hours ago, nurber3 said:

I was just looking for a similar feature in the manual and think this would be a handy addition to Waveforms.  In Picoscope jargon they call it a reference waveform.  You just identify a capture as a reference and the software identifies it as a regular channel with an appended number.  Last I used this feature Picoscope didn't provide transparency which I see Waveforms has and I think would be useful to accentuate capture over reference.  I'd always wished Picoscope would have a cloud service for upload & download of reference waveforms ( with powerful search capabilities ).  Picoscope provides but only for automotive which always seems to deny others from interesting collaboration.  Linked video intro to waveform library including reference.

There is a free waveform exchange for pico automotive waveforms at Level 1 automotive training here :  https://www.l1training.com/waveform-library/

you can share your own waveforms there if you want to.

I do use reference waveforms with the Analog Discovery. I just hit add channel, reference, channel 1 and it adds the current trace as a reference...

or with the curve tracer I just hit the + then choose add trace as reference... I like the one step in tracer app

good for comparing my junkbox parts...

[korn]

6 hours ago, attila said:

Hi @korn

 

looks really good. amazing work. Thank you!

I should have included more examples. I only gave you the 4 cyl where the power stroke is offset by 180 degrees

on a v6 power stroke is offset by 120 degrees

and on a v8 it is offset by 90

offset = 720 / #cyls for most even fire engines.

there are oddball odd fire motors out here too. you cant account for them all....

or even the old "real" Harley Davidsons that have 2 cylinders with a 315 - 405 offset.

it is what gives them their distinctive "ba da lope" sound.

here is an example of a 6 and 8 layout

[attila]

Hi @korn

Theoretical 5 cylinder overlay will look like this in the next sw version:

[korn]

9 hours ago, attila said:

Hi @korn

Theoretical 5 cylinder overlay will look like this in the next sw version:

 

I think that is good. I have stayed away from 5 cylinder engines. Closest I got was when I rented a chevy colorado from home depot.  Since they have a 72 degree offset on the crank the formula should be right at 144 on the power stroke..

Maybe there is a gm volvo audi or fiat person lurking out there who could chime in.

I appreciate the effort to accommodate us car guys. 

would it be passible to have check boxes for the lower graph of tick marks and the upper color overlay to make them individually  invisible?

sometimes we only need the overlay and others just the tick marks. sometimes both. It depends on the pickup sensor being used.

I have to play with this this weekend on a live engine. gonna be fun.....

 

Update:

had to come back and edit this post .... Just realized if I'm only looking at a sensor for one cylinders events I just have to set the number of cylinders = 1 no matter how many there really are and the color overlay still works. I dont think we need those checkboxes at all. Unless your bored at want to add stuff..

My father always said I over-engineered things. His favorite saying was " Good enough for government work"....

I learned to live by that one after I worked at my first GSA customer....

Edited July 20, 2023 by korn

[attila]

Hi @korn

 

[korn]

That looks great. Thanks!

I just got an AD3 for the bench so my old AD2 has been dedicated to auto testing and lives on the side of my toolbox now....

I have to save up for a, ADP3450 now so I can have 4 channels.....