KISS ESC problem

[chris24g]

using fw: aqv7.1.1852-hwv8.6-ext_esc

Cannot get the ESC to ramp smoothly in RPM. At low RPM the motor does rotate but vibrates and makes a buzzing noise (like it is struggling for sync).

To confirm ESC/motor compatibility, I used a servo tester on the ESC signal line. The motor is smooth and operates normally.

I am using the N4 expander, BUT I also tried grabbing the signal line from motor 2 on the board itself, and get the same results (the only difference is that the buzzing occurs at low throttle on the N4 and mid throttle on the m2 output.

I have tried using SBUS/PPM receivers as well, but they have no effect.

[Astudillo]

Hi Chris,

Did you already try Menno's firmware?(PID) (Quatos)

With this firmware you can calibrate the endpoints of your esc's and run a PWM thrust calibration.
If you set MOT_ESC_CALI to 2, an restart your M4 in the QGC you will get this in you communication console.

PWMcalibrate.jpg (119.41 KiB) Viewed 17345 times

It will just go trough different PWM value's with a left roll on you receiver. If its still giving strange noises its probably a hardware problem, if it runs smoothly like with the servo tester. than its probably a software issue.

P.s. Don't forget to strap down you machine if your going to do the calibration run!

[afernan]

I´m pretty sure you have a vibration coupling issue with your frame. KISS and AQ are so quick and sensible that AQ try to "control" arm vibrations that causes strong interactions with KISS (big vibration and noise)

Try reducing drastically Tilt Rate D (from 32000 to 7000).
Try also move the Tilt Rate F (ramp rate: F=0.1 means we need 10 steps to apply 100% change).
Try reduce Tilt Pos P and D
Read this: http://autoquad.org/software-downloads/?did=127

Angel

[aBUGSworstnightmare]

You may also want to check the PIS Parameters of this craft viewtopic.php?f=25&t=4543&start=10#p33919
It's a quite 'noisy' frame but performed well after some PID Tuning.
F-Terms are dialed down (as Angel alreday suggested). From my experience during tuning of the craft I had to dial up TRD (Tilt Rate D) at some point again since a TRD too low caused the craft to start wobbling.

In case of KISS ESC you Need to adjust your ESC Parameters to something like this:
MOT_ARM 1055
MOT_MAX 1950
MOT_MIN 1080
MOT_START 1095
(used these settings on M4 + KISS)

[chris24g]

I flashed Menno's FW and ran through the PWM calibration/test

The motor behaved normally at each PWM step. For those that haven't tried this, the test starts at a PWM value of 1000 and increments by 100 until 1800 PWM (full throttle). Of course, props off guys!

Unfortunately, even with Mennos FW, the motor stil vibrates, but now it is pulsing/vibrating (is this an X rated forum lol).

Afernan had a good idea, but I only have one motor/esc wired up. Even if I hold the arm to dampen any vibes, the motor will still go wonky.

So what I do know is that a clean PWM from either a servo tester or through the AQ test mode itself is fine. There must be something in the code that the KISS doesn't like.

[aBUGSworstnightmare]

[afernan]

I sugest to move to QUATOS instead of PID, if you have a M4-N4. It works very smooth and much better than PID.

Quatos is a much less sensible to vibrations.

Angel

[chris24g]

After trying different PIDs, firmware and both PPM outputs from the AQ and expander board itself, I was not able to solve the problem. The KISS escs did work with fine with a different motor, though, so it may just be that these particular ones are not compatible. These motors are from the cheerson cx-20, basically 3S phantom motor clones. I don't know the particular specs off hand.

I've swapped the old cheerson ESCs back in and the motors work fine, as expected.

[aBUGSworstnightmare]

[chris24g]

params file