Request for some infomation on changed PID values

[HeliHenkie]

Hi all,

I've been away from the AQ project for about a year now, but and with the arrival of the new DIMU board I'm giving it another go.
After flashing the latest experimental firmware, designed for working with the DIMU board, I looked at the PID values and saw completely different values from a year ago. At first I thought it was a mistake but I found some limited reference to these changed values.

Can someone tell a little bit more about this?

Furthermore I was asking myself the question if it's possible to load the old PID values in the new firmware. Will this lead to problems? If so, what's to be expected?

Best regards,

Jan Willem
The Netherlands

[Max]

HI Jan,

Essentially, due to internal changes in the firmware to account for greater resolution via CAN bus control, some of the PID values have been multiplied by a factor of 4.82. QGC 1.3 has a calculator to convert the settings if it detects old values with a newer firmware version. Described here (3rd screenshot and down): viewtopic.php?f=32&t=2419&start=80#p16001 But if the calculator doesn't work for whatever reason, you need to convert the relevant values yourself (you can see which values are affected in those screenshots).

HTH,
-Max

[epyonxero]

Ive been having some weird flight behavior since Ive been using FW with the new PID values on both an AIMU board and a brand new DIMU board. With the default PIDs from FW aqv7.0.r372.b1704-hwv6.1-dimu1.1 on the DIMU board the copter flies like the PIDs are too high with a lot of oscillation. Reducing the PIDs to a level similar to the old defaults seems to calm things down but its still not what I would call smooth. In trying to find what the new defaults should be I looked at the screen shots in the link above I see the Tilt_Rte Max parameters are 4815 but the default I have from the FW is 9999. Which is correct?

Surging/oscillation in PH

[SuperSharpShooter]

I've just had my first flight with r372 w/DIMU on a QAV540g w/simonk ESCs (heavier front/back so the roll mixer has been reduced to 85), but I'm getting really bad performance. It's pretty much impossible to hover, I get surging up and down, wobbles on roll & pitch, and fast yaw twitches. Just spend the last half hour trying to tune the PIDs (reduced TRD by half, and tilt angle PIDs too, and tried increasing the yaw xM values which helped previously), but still getting massive amounts of clipping on the motor outputs, and it doesn't really feel any closer to working well.

Does anyone have a good strategy for tuning PIDs with the new FW?

[epyonxero]

Anybody? Is it possible to make a DIMU version of the FW with the old PID values as a comparison? It sounds like were both having the same problem.

[13brv3]

[epyonxero]

Can someone from the development team please take a look at the issues above?

[sandmen]

To make a fw, with old PID's makes absolute no sense.
Also reducing the Mixing values, is not the correct way !
Changing the mixer, could makes sense, when we have a different geometry in the motor distance to center.

[bluuu]

It looks like a rezonanse on gyro/acc. Your FC is on dampers ? or hard mounted ?
Probably its problem with unbalanced motors and props.
(I had similar problem when my FC was mounted on rubber dampers).

[epyonxero]