Cam is Always 5 Degrees Behind CamCMD

2012+ US/Canadian Civic Si / 2013+ ILX
Post Reply
bigbadspoon
Posts: 34
Joined: Wed Mar 13, 2013 3:20 pm

Cam is Always 5 Degrees Behind CamCMD

Post by bigbadspoon » Sat May 07, 2016 11:20 am

Hello,

I've noticed very recently that my actual cam angle is trailing the commanded angle by 5 degrees in all situations.

I pulled up some datalogs from previous runs and this has only started fairly recently. I think a recent update to FP Manager may actually be responsible, but I'm not sure which parameter threw it off and I wasn't paying close enough attention to remember what version I was running and when. The only notable parameter change I've seen from the previous version I was running was that VTC I in VTC closed loop control now set the -60 parameter to .4 instead of 0, like previous versions. However, I see the same situation in open loop as in closed, so I wouldn't think this is responsible.

I've attached 2 calibrations. My logs for New Tune 1.00 show no variance between cam and cam cmd, but in New Tune 1.02, there is now a 5 degree lag in the cam. I included datalogs from both tunes, as well.

Any help you can provide would be much appreciated!
Attachments
New Tune 1.02.fpcal
(21.24 KiB) Downloaded 72 times
New Tune 1.00.fpcal
(20.96 KiB) Downloaded 75 times
datalog0000 (cam lags).fpdl
(2.28 MiB) Downloaded 77 times
datalog0000 (cam OK).fpdl
(2.4 MiB) Downloaded 84 times

bigbadspoon
Posts: 34
Joined: Wed Mar 13, 2013 3:20 pm

Re: Cam is Always 5 Degrees Behind CamCMD

Post by bigbadspoon » Sat May 07, 2016 6:33 pm

I updated to FP 2.3.7 and compared the calibrations after downloading and re-uploading. The VTC PID tables now match "New Tune 1.00". I ran a datalog and the Cam and CamCMD graphs are now essentially line-on-line again.

bigbadspoon
Posts: 34
Joined: Wed Mar 13, 2013 3:20 pm

Re: Cam is Always 5 Degrees Behind CamCMD

Post by bigbadspoon » Sat May 28, 2016 4:03 pm

On closer inspection, there appears to be about +/-2 degree slow oscillations compared to datalogs I took back when I was running a FP 1.5.x back in 2013.

Did you guys change values when importing those VTC PID tables? If so, could you please post what the Honda original values are?

Also, why are these kinds of changes not included in the official changelog? Not just value changes, but even the addition of the tables.

User avatar
Hondata
Site Admin
Posts: 8766
Joined: Thu Aug 15, 2002 12:13 pm
Location: Torrance, CA
Contact:

Re: Cam is Always 5 Degrees Behind CamCMD

Post by Hondata » Sun May 29, 2016 6:16 pm

Create a new calibration and see if the VTC PID values are the same as your calibration.
Hondata

bigbadspoon
Posts: 34
Joined: Wed Mar 13, 2013 3:20 pm

Re: Cam is Always 5 Degrees Behind CamCMD

Post by bigbadspoon » Tue May 31, 2016 3:51 pm

The values don't change when making a new calibration compared to what's in mine. I tried pulling in a few of the basemaps to see if there were any different ones, but they're all the same.

User avatar
Hondata
Site Admin
Posts: 8766
Joined: Thu Aug 15, 2002 12:13 pm
Location: Torrance, CA
Contact:

Re: Cam is Always 5 Degrees Behind CamCMD

Post by Hondata » Wed Jun 01, 2016 8:26 am

If the PID values are the same then it is not the ECU control.
Hondata

bigbadspoon
Posts: 34
Joined: Wed Mar 13, 2013 3:20 pm

Re: Cam is Always 5 Degrees Behind CamCMD

Post by bigbadspoon » Wed Jun 01, 2016 6:20 pm

The PID values are the same if I create a new cal since those tables were added. Since those tables were not available when VTC worked correctly, it's hard to say if they're the same now.

It's definitely not a mechanical issue, because I dug out my old mechatronics textbook and spent about 2 hours idling in my driveway tuning the PID values on the live table by stepping the angle up and down and changing the PID until performance was similar to stock. It tracks pretty well now and there's no offset or saw-toothing. The response is roughly equivalent to stock (0.3 second delay on step input), but it seems like there's room to improve. I'm not a PID expert, though; just an amateur.

Post Reply