Martian II with rs2205 2300kv and dys XM20A pids?
« on: May 21, 2016, 09:56:05 pm »
Hey I'm about to give up on this hobby! Been trying to tune pids for my martian fpv frame with rs2205 2300kv and dys XM20A with 4s no matter what I do it won't fly and low stick on the throttle acts like 50% throttle!

f5soh

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Re: Easy tune problem martian rs2205 XM20A
« Reply #1 on: May 21, 2016, 09:57:31 pm »
Hi, welcome.

Post your config file: File > Export UAV settings with board connected.

Martian II with rs2205 2300kv and dys XM20A pids?
« Reply #2 on: May 21, 2016, 09:58:27 pm »
Please tell me that someone has pids for the martian 230mm frame with rs2205 2300kv and dys XM20A on 4s
I'm about to give up I just can't do it :(

Re: Easy tune problem martian rs2205 XM20A
« Reply #3 on: May 21, 2016, 10:14:29 pm »
wont allow me to attach it here :(

Re: Martian II with rs2205 2300kv and dys XM20A pids?
« Reply #4 on: May 21, 2016, 10:15:08 pm »
How bad is it, what are you trying to achieve?

The setup you described is pretty similar to what I fly and default PIDs provide decent flying characteristics and a good starting point for further tuning...

How are your outputs set up? If you have them set to 50Hz PWM, that might be a source for bad performance.
Have you done sensor and output calibrations correctly?

Re: Martian II with rs2205 2300kv and dys XM20A pids?
« Reply #5 on: May 21, 2016, 10:45:00 pm »
It's very bad.

I originally clicked on x frame when setting up don't think I tryed stock pids will try that tomorrow.

I'm just trying to get it flying to  e honest.  I just fly under tree in open spaces etc.  I tryed lptune app but it's give me weird values like 124.7000 for my Pids once I got my ouv etc

f5soh

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Re: Easy tune problem martian rs2205 XM20A
« Reply #6 on: May 21, 2016, 10:45:28 pm »
Really ?

Just bellow the area you enter your message there is all you need.

Re: Easy tune problem martian rs2205 XM20A
« Reply #7 on: May 21, 2016, 10:47:30 pm »
Won't pick up the format of the uav

hwh

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Re: Martian II with rs2205 2300kv and dys XM20A pids?
« Reply #8 on: May 22, 2016, 03:52:08 am »
I've merged your two topics about this into one. Asking the same thing two places is counterproductive since the people helping in one thread may not be aware of what you're doing in response to answers in the other thread.

The first thing you need to do is get your computer and web browser working properly.  If you can't select the uav file to upload your web browser has problems.  You might try a different browser.

Re: Easy tune problem martian rs2205 XM20A
« Reply #9 on: May 22, 2016, 10:07:04 am »
Won't pick up the format of the uav

You should be able to upload .uav files to this forum, but you could try tenaming it to a .txt file or something.
Or maybe you need to select All Files in the file type selection menu, which should be somewhere near the bottom of the Open File window.

Re: Martian II with rs2205 2300kv and dys XM20A pids?
« Reply #10 on: June 18, 2016, 06:26:41 pm »
For anyone reading this thread:  This is a known issue.  PID oscillation is the cause.  The oscillation can be so fast and thus visibly so small that it is difficult to see.  PID oscillation can come from a couple different places.

The reason is that LP code has a feature where if the throttle is low and it needs a _lot_ of motor thrust for stabilization, it will effectively increase the throttle, just so it can have more stabilization to try to keep the aircraft level.  It will also reduce the throttle if you have the throttle stick at 100% for the same reason.  It's easy to see that no stabilization is possible if the motors are at 0% or 100%.

Previously, if the motors were at 10% and it needed +-20% for stabilization, it would increase one to 30 and decrease the other to -10.  Well the motor can't run -10.  It runs zero so you get e.g. some yaw when all you want is roll.

Now throw in some reason for an out of control PID oscillation and no matter where the throttle is set, it is driven to 50%, just to be able to apply maximum differential (stabilization) control.

The solutions are:
- balanced props (don't just skip this, it is the most important)
- increased GyroTau (GCS -> Configuration -> Stabilization -> Expert -> GyroNoiseFiltering)
- reduced PIDs (experiment to find out which, suspect the D terms)