Noob Attitude mode question
« on: December 24, 2015, 07:02:20 am »
Hi everyone, I am new to this so please bear with me.
I was flying my Eachine 250 in attitude mode. When I let go of the stick in full forward or reverse, the quad will level out but with a slight nose down pitch in the travelling direction. Is that normal? If not, how can I correct it?
Thanks in advance.

ArnhemAnt

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Re: Noob Attitude mode question
« Reply #1 on: December 24, 2015, 10:50:15 am »
Hey man - no issues with a 'noob' question. We are all learning.

Your scenario could be due to a few things.

- Have you checked your Centre Of Gravity (COG)? with LiPo connected?
- Have you tuned your frame yet with the PID tuning?

There are other influences as well.

Maybe a short video showing the issue would be a help?

A tuned frame, that is balanced, should pretty well hold hover in Attitude mode with no stick inputs. Keep in mind that this is without a GPS, so there is still the possibility of some drift.
If you do what you need, you’re surviving. If you do what you want, you’re living.

Re: Noob Attitude mode question
« Reply #2 on: December 24, 2015, 05:43:26 pm »
It's the eachine 250 racer from banggood. From what I've read, it's known to be tail heavy.
I have posted the same question in rcgroups eachine forum. One comment was to check the rx neutral and end points. Also the attitude and rate slider. Not sure what they are.

Re: Noob Attitude mode question
« Reply #3 on: December 24, 2015, 06:14:14 pm »
Are you saying that when tilted backwards, it continues to tilt a little backwards, and when forwards a little forwards?

If so it sounds like your PIDs need tuning.  You might try increasing 'I' on pitch (and roll) a bit.  Maybe multiply the current value by 1.25 for a test.  Make sure that doesn't cause a lot of oscillation though.

Re: Noob Attitude mode question
« Reply #4 on: December 24, 2015, 07:59:16 pm »
Thanks for the tip.
For attitude, I guess I am using the basic setup the bottom slide bar?
Thanks in advance
« Last Edit: December 24, 2015, 08:03:59 pm by blown68ssrs »

Re: Noob Attitude mode question
« Reply #5 on: December 24, 2015, 08:48:33 pm »
First of all, one typical problem is using a cloud configuration that doesn't exactly match your rig...  One suggestion in that case is to try stock PID values.

I have never been an Attitude mode tuning expert (if such a thing exists), but for what you describe, I would try each of these and if they don't help, put them back where they were and move on to the next:
- Inner Loop - Pitch (and Roll) - Integral - multiply by 1.25
- Outer Loop - Pitch (and Roll) - Proportional - multiply by 1.25
- Advanced Page - Outer Loop - Pitch (and Roll) - Integral - Try 0.5 or 1.0 (or higher) and see if that helps.
On that last one there is an ongoing discussion that says that you shouldn't have non-zero 'I' term in both inner and outer loops.  I would say that you can, but the sum of them must be kept low enough to avoid oscillations.  If e.g. 0.00800 (inner) and 0.0 (outer) are just below oscillation and 0.00000 and 1.5 are barely below oscillation then 0.00400 and 0.75 are probably OK too.

The only bad thing from slightly high values is slight oscillation which isn't usually too big an issue unless you are an absolute beginner, and then just be careful, fly it over grass, don't let it get more than chest high, and immediately cut the power to zero if anything out of your comfort zone happens.

Re: Noob Attitude mode question
« Reply #6 on: December 24, 2015, 09:06:29 pm »
Thanks for detailed tips.
I will give it a shot when the weather warms up a bit.
Merry Xmas

Re: Noob Attitude mode question
« Reply #7 on: January 02, 2016, 11:27:01 pm »
Hi,
I think my question suites best to this thread. I am as well a total beginner. I am not sure where to start with my PID and whatever adjustments are needed for my QAV250 clone. At the moment I am trying to fly with attitude mode.
My aim is for the beginning: hovering/leveling and carefully pace around.

And here my questions start: what is the best for a noob to choose in the "Flight Mode Switch Settings" tab:
Roll: Attitude; Pitch: Attitude; Yaw: Rate; Thrust: Manual? (it what I have at the moment)

Next question which might be based on my above mentioned flight mode settings: do I start adjusting the "Attitude Stabilizations" only and leave alone the "Rate Stabilizations".
I read somewhere that the rate adjustments are basic and influence the attitude PID values. If this is true then adjusting with the rate values would be better.

And then there is this Thrust PID Scaling (TPS) in the advanced tab of the stabilization settings. I am not sure if I understood what it is for, something like an expo for the PID values the more throttle I give to the quad (?). Should I turn it on or off? Is it necessary for a noob, especially due to my above mentioned aim?

I am using a Taranis, so I'd like to adjust whatever has to be adjusted first with my potis. At the moment I'm fiddling around with the rate values, although my flight mode is set to attitude (see above). Hhhm, I unsure if this is correct to start with.

Could someone be so kind and help me? I am totally confused, and I really did big searches on the internet (yes, also youtube).

Thanks in advance, and yeah, Happy New Year ;D

ArnhemAnt

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Re: Noob Attitude mode question
« Reply #8 on: January 02, 2016, 11:53:21 pm »
Hey man. I think I can help. I've put my suggestions below to each of the questions you have asked. Welcome to LP.

Hi,
I think my question suites best to this thread. I am as well a total beginner. I am not sure where to start with my PID and whatever adjustments are needed for my QAV250 clone. At the moment I am trying to fly with attitude mode.
My aim is for the beginning: hovering/leveling and carefully pace around.

- I presume you are flying without a GPS? If so, keep in mind that the Attitude mode may hold in hover, but it may still 'drift'. I mention this as some new users expect the hover to be similar to a GPS position hold.


And here my questions start: what is the best for a noob to choose in the "Flight Mode Switch Settings" tab:
Roll: Attitude; Pitch: Attitude; Yaw: Rate; Thrust: Manual? (it what I have at the moment)

- That's a good start. I use nearly the same settings, but I have my Yaw set to Axis Lock.
How many flight modes do you have set up? If you have more than one, then try your settings on flight mode 1, and try mine on flight mode 2 and see if you notice any real difference. I'll talk more about flight modes at the end of this post.

Next question which might be based on my above mentioned flight mode settings: do I start adjusting the "Attitude Stabilizations" only and leave alone the "Rate Stabilizations".
I read somewhere that the rate adjustments are basic and influence the attitude PID values. If this is true then adjusting with the rate values would be better.

- First question. When you have been flying so far, have you noticed any oscillations either at hover or while moving? If not, then it may be a good idea to leave the default settings. These are a very good starting point and are quite flyable.
If you do need to make changes, and you are only flying in Attitude mode, then it is my understanding that the Attitude Stabilization section is the one that requires more attention. In my experience, I usually drop the numbers for Roll and Pitch 'P' but don't make changes to Yaw at all. For example: Roll: 1800 and Pitch: 2200 with Yaw staying at 2500. I don't touch the 'I' in the Attitude Stabilization section.
You can get really bogged down in the PID stuff and fiddle for ages, but I try to find something simple that works and then just go flying. To me it's about the flying and not the tinkering.

And then there is this Thrust PID Scaling (TPS) in the advanced tab of the stabilization settings. I am not sure if I understood what it is for, something like an expo for the PID values the more throttle I give to the quad (?). Should I turn it on or off? Is it necessary for a noob, especially due to my above mentioned aim?

- TPS is more beneficial when you are using the full throttle scale and going from slower flying to warp speed as it scales your PID's according to your throttle input. It also helps eliminate the prop wash effect when descending. It is not necessary to use when starting out, in my opinion.

I am using a Taranis, so I'd like to adjust whatever has to be adjusted first with my potis. At the moment I'm fiddling around with the rate values, although my flight mode is set to attitude (see above). Hhhm, I unsure if this is correct to start with.

- Can't help you here. I don't have a Taranis and I also don't use expo in my radio.

Could someone be so kind and help me? I am totally confused, and I really did big searches on the internet (yes, also youtube).

Thanks in advance, and yeah, Happy New Year ;D

A few more suggestions. If you have the ability to set up a few flight modes, then try this. All done in the Advanced section of the Stabilization tab of the GCS
Set up flight mode 1 to match bank 1. In the Responsiveness section leave the inputs at default. The defaults for Attitude mode response are 55, 55, 35. This tells you the maximum degrees that the frame will move with full input from your sticks.
Now, in Flight Mode 2, tick Advanced Configuration and maybe try the following: Roll: 90, Pitch:90, Yaw: 90. This will give your frame a faster response with the same stick inputs
For the third Flight Mode, increase these numbers a little more.

I use this for some of my frames and find it very useful particularly when I have a variety of flying to do. For the slow video stuff, I use the defaults, then when I want a slightly more 'aggressive' flying style, then I move to another flight mode with the higher response mode.
This my be helpful for you as you are learning so that you can practice with the defaults, but then try a higher response mode as you improve.
Just a suggestion and hope it helps.

Happy flying.
« Last Edit: January 02, 2016, 11:56:50 pm by ArnhemAnt »
If you do what you need, you’re surviving. If you do what you want, you’re living.

Re: Noob Attitude mode question
« Reply #9 on: January 03, 2016, 12:25:05 am »
wow, what a long answer. Thank you ArnhemAnt. I'll try your suggestions tomorrow - in Germany it's night time and I am on my way to bed. I'll give you infos after playing around with librepilot based on yr suggestions.

Ah, just one thing, yr right, I do not have GPS stick to CC3D, I have one on my OSD (tarot TL300L ->banggood.com) which is independet from the flight controller.

Thank you so far, good night!

ArnhemAnt

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Re: Noob Attitude mode question
« Reply #10 on: January 03, 2016, 01:35:30 am »
^^ Happy to help where I can. Keen to get your feedback after you have given the suggestions a try. I think you'll find your way around it all.
If you do what you need, you’re surviving. If you do what you want, you’re living.

Re: Noob Attitude mode question
« Reply #11 on: January 04, 2016, 11:18:34 pm »
Hi ArnhemAnt
at the moment I can only try your suggested adjustments and little bit of variations of them in my hobby cellar, which is not too big or either high, so I have there the prop wash effect. I guess this is the right term, if a helicopter, quadcopter or whatever copter is near the grond with rotating props.

The weather is lousy, rain, rain and again rain. On next weekend it should be fine, at least the forecast man says so. Then I could try flying outside.

So man, I am still inn, but have to be bloody patient :(

ArnhemAnt

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Re: Noob Attitude mode question
« Reply #12 on: January 05, 2016, 12:33:09 am »
LOL. All good man. I feel your pain. Nothing worse than crappy weather to spoil a good flight. Fingers crossed for better weather next weekend for you.
If you do what you need, you’re surviving. If you do what you want, you’re living.