NVH Road Test

Ask questions relating specifically to the PicoDiagnostics NVH equipment and software here.
Technician
TwoWaves
TwoWaves
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NVH Road Test

Post by Technician » Sun Aug 04, 2019 1:45 pm

I've been doing a bit of learning with the NVH kit. I was concerned that the road noise from the Fiesta seemed quite loud and thought I'll use the NVH equipment to record some tests!

I entered the transmission gear ratios from the manufacturer but could not find the final differential ratio, therefore using a little trial and error I mathematically worked it out. I can't guarantee it is exactly correct because I don't really know what vehicle speed the manufacturer uses in their calculations!

Having now completed a road test I can tell from the software and the actual gear changes that there is a slight variation observed. I could now using the software refine the results even further if necessary but at this time my concerns are understanding how to use and setup the NVH kit, and research the help files.

During a road test the NVH software stopped recording and came on screen with an error report. The main concern there was for some reason the software lost communication with the PicoScope. Yes I'm connected using the BLUE lead. As far as I can understand I have still managed to save the data. I did also try and save the error report but the software froze and I was not able as far as I understand save the file!

When I connected the computer back to WiFi and tried to run the help files with the NVH software running, the help files menus cannot be selected because they are saying that access to the server (pico) is not possible!

Something must have changed?

With the older version software I was able to access the help files whether I was connected to the internet or not. Since the software update am I now to assume that all the help files are stored on your server and not accessible without it?

If this were the case it might be a problem from a mobile point of view because the technician can't access the files when stopped on the side of the street if necessary?

After carrying out the road test and playing back the data files I was not convinced that a real problem actually exists!

So then I thought if this is just road noise I'm experiencing then I need to connect the microphone and setup the NVH for noise and carryout a further road test!

So not really knowing exactly how to set it up to measure noise, (and no help files available) I went into the options and selected (dbg). With the microphone connected I tapped it a few times with my fingers and could measure and record and response. During playback I'd of thought I should be able to listen to the noise but this seems not possible?

Clearly this is a learning curve for me at this time, but could somebody please look into the help files and advise me how if I'm doing it wrong, I go about setting up for recording noise please.

Thanks

Steve Smith
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Re: NVH Road Test

Post by Steve Smith » Mon Aug 05, 2019 2:29 pm

Hello and thank you for the post

Nice work on the differential ratio calculation.
With a FWD vehicle this is not required as this is used predominately to calculate Propshaft speeds

With that said it is always good to include as much information as possible, especially if you are chasing a differential whine.

Regarding the software freezing and error report, could you confirm if this was a “Crash Report” or did the software hang?

Could you confirm the integrity of your PC USB socket with a wiggle test as worn USB port has the potential to generate havoc!

Forgive me here as I am a little confused, have you managed to save and recall recorded data?

I am not sure why you received the error message re access to the Pico Server unless our server was momentarily off line whilst collecting NVH usage stats

You most certainly do not need to be on line/connected to the internet to view ANY NVH help files, connection files of NVH theory files. (NVH Theory files however require an NVH license key which you have)

In order to measure sound and vibration simultaneously could you refer to the help file re 3 Axis + Single Channel if you have 2 x NVH interfaces?

IMAGE 1.jpg
3 Axis + Single Channel

Could you also follow the video below?

NVH Video 6

I hope this helps, take care……Steve

Technician
TwoWaves
TwoWaves
Posts: 517
Joined: Thu Apr 24, 2014 8:32 pm

Re: NVH Road Test

Post by Technician » Mon Aug 05, 2019 5:13 pm

Thanks Steve, I'll let you know, the information if recorded is on my laptop at home.

I've had a look on the pc and because the saved file is not a file that I gave a destination to, if the file has saved, I'm not sure where to look on the hard drive to find it. Any help here would be much appreciated to locate it, but if not I'll do some more road tests and see if it reoccurs, and if so I'll photograph it and upload.

Technician
TwoWaves
TwoWaves
Posts: 517
Joined: Thu Apr 24, 2014 8:32 pm

Re: NVH Road Test

Post by Technician » Tue Aug 06, 2019 6:39 pm

Hello Steve,

I've watched the video and can see where the adjustments are for sound now, thanks for that. I could be misreading the signals here but I got the impression that Frank was saying that a gasoline engine was diesel somewhere in the videos 6/7 I think!

Technician
TwoWaves
TwoWaves
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Joined: Thu Apr 24, 2014 8:32 pm

Re: NVH Road Test

Post by Technician » Tue Aug 06, 2019 11:40 pm

Hello Steve,

So I've still got problems. Reading your post above and taking on board what you advise, I deleted the differential ratio calculation and left that part reading 0.00. I used just the gear ratios and the tyre sizes, however, this has not worked at all, the graph produced from the NVH kit does not record MPH or gear changes. Also the scope lost communication again but did not provide a screen shot of the failure this time. I did have to unplug the scope and then reconnect it to ensure that the software functioned again.

I did setup the software as you instructed to record sound, and I did complete a road test and saved the file. When I tried to play back the file the laptop (Windows 7) will not play back the recording, the screen freezes. I did try this several times and I get the same result each time.

I decided to download the pico software onto a new Windows 10 laptop and transfer the NVH file from the Windows 7 laptop via a dongle to the Windows 10 laptop pc. Each time I try to run the NVH software for the sound recording the NVH file just freezes and I end up shutting down the laptop to start again. If I open any other NVH software file that records vibration then those files will play as normal every time without a problem. I don't have a solution at the moment!

Technician
TwoWaves
TwoWaves
Posts: 517
Joined: Thu Apr 24, 2014 8:32 pm

Re: NVH Road Test

Post by Technician » Wed Aug 07, 2019 9:42 am

I've spoken to the technical help line this morning and agreed that another road test should be completed because the final drive ratio must not be 0.00. The calculated value I worked out did work and allowed gears to be shown on the NVH display. After speaking to the technical help line I have changed the differential ratio to 1.10. I completed a further road test and this ratio did not allow the software to record any data. I have changed the settings back to my own calculation and tried to follow the above settings from Steve's post regarding sound recording. The NVH software has recorded data but now when recording sound the gear ratios do not show up as gear changes correctly using these settings.

I think maybe most of the concerns here might be basic settings which should be tailored to each type of NVH kit purchased, meaning how to set the kit up based on the installed components sold with it. The videos are a great help but I think more help in showing how to set up the software to use the NVH kits might be very helpful for us beginners in this trade. I'll try to upload the files so you can see where I am going wrong and hopefully point me in the correct direction. I'll not add any additional files just yet as it could become confusing to sort out the problems!

This is another problem the uploads attachment software shows up when trying to load files;

ERROR
File too large: NVH road test requires final drive ratio to work.pddata

Technician
TwoWaves
TwoWaves
Posts: 517
Joined: Thu Apr 24, 2014 8:32 pm

Re: NVH Road Test

Post by Technician » Wed Aug 07, 2019 4:44 pm

Just an update on this thread. I have found quite by accident that the software will only run in reverse. I've tried to look at the signal generator that appears to be used for sound but is grayed out so I can't select that option. The picoscope diagnostics error appears when I try to play the sound recording in a forwards direction, but as just advised will run in reverse. The error notice appears each time the play button is depressed in a forwards direction and asks for information about the problem and the operator can type in notes and put the email address in, however the software freezes and will not either send the report or allow it to be saved to file for later viewing or sending.

Steve Smith
Pico Staff Member
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Re: NVH Road Test

Post by Steve Smith » Fri Aug 09, 2019 8:58 am

Hello and thank you for the continued feedback.

The Function Generator function is "greyed out" by default and will only function when a NVH licensed automotive scope is connected to the PC.

Given you have an NVH licensed automotive scope, yet the Function Generator remains greyed out, suggest the software cannot see or connect to the scope.

This also ties up with your loss of communication with the scope during road test.

This concern must be tackled before moving onto other issues as we will forever be chasing "glitch behavior" that may well be attributed to connectivity.

It is unlikely that our connectivity issues are software related.

The next probability is the Scope, USB Link or the PC.

We can remove one of these possibilities by recovering your scope to Pico and testing the device to ensure the integrity of the Scope & USB link up to the PC

Once we are happy with the scope (which we will also confirm with additional road testing) we can then move onto the PC

Could you locate your recorded NVH file of concern and send into support@picotech.com and I will take a look at the settings and issues surroundings playback?

If you would like to send your scope for testing then again, please email the support email and we will process this request ASAP

If you also locate a trace file for the issues you have experienced with connectivity that would be most helpful too.

Ideally we need to the scope to have suffered a connectivity issue, once this occurs, close the NVH software where a trace file will automatically be written to the AppData folder.

To locate the trace file could you take a look below:
TRACE FILE LOCATION INC WINDOWS 10.pdf
Trace file location
(161.21 KiB) Downloaded 9 times
Once again please send this to the support desk as the trace file will contain details about your PC etc.

I hope this helps, take care.......Steve

Technician
TwoWaves
TwoWaves
Posts: 517
Joined: Thu Apr 24, 2014 8:32 pm

Re: NVH Road Test

Post by Technician » Fri Aug 09, 2019 12:10 pm

Thanks Steve for your feedback. Given that we have already been down the road of sending the scope back previously for noise issues and I'm still having problems with connectivity, which I don't think you would have been aware of back then, because the help line suggested my problems could have been down to the USB cable at that time. Maybe you could recommend a new scope for me to purchase as technology is moving on-wards, and this scope is getting maybe long and old in the tooth nowadays!

Thanks

Steve Smith
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Re: NVH Road Test

Post by Steve Smith » Fri Aug 09, 2019 2:18 pm

Thank you for the feedback.

Rest assured your scope specification and performance is fine and a better scope today then when developed thanks to the hard work of the software team here at Pico.

NVH performs well regardless of scope age as just this week I have been supporting the use of a 3223 model with vibration analysis which I believe is either the same as your scope or, you may even have the first generation 4000 series?

Either way, if we have proven that you scope USB connectivity/link is fine then replacing your scope for the latest model will not cure our connectivity issues as this is looking more and more like the PC

I hope this helps, take care......Steve

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