One Quad, One Girl, Four Flights and One Huge Cheshire Cat Smile!!!

[bunnygirl80]

Hi guys,

Well! I';m now sat here in front of my open fire with my third glass of wine and memories of a superb day. I turned up at my local aero club not sure if they would welcome me without my usual plane. I was secretly hoping that the field would be empty when I got there, but alas no, the weather was too good and six other members had ventured down! So, I left everything in the car and walked over to Ron one of the eldest flyers thinking "no flying for me then". He shouted "Hi Stef" as he leant over his plane trying to find his teeth which had fallen out and landed in the cockpit of his spitfire. "What you flying today" he shouted! "Turn your hearing aid on" I shouted...

Okay, that';s enough of my creative writing. Anyway, after pinching Ron';s bum a few times, he was kind enough to let me to fIy to one side of the field. To everybody';s amazement, I had four superb flights with no incidents. After telling everyone that it was my sixth flight and that I was learning, I think everyone expected a major crash! I did a few circuits and flew the quad like a plane, not sure if this is the right way, but hell did it feel and look good. I';m really loving and getting into this. What made it even better was my decision to flip the return to home (RTH) switch half way through the third flight! Wow, everything I said about the Crius SE I take back. My little quad turned towards me whizzed back and hovered over my head until I reduced the throttle to make it land. Amazing when you see it for the first time. The most difficult thing was trusting it to do it itself. I then used it another three times pretending that it was my flying that was bringing it back! It was sooo funny! I';ll leave you with that picture!!!

Okay, no posting would be complete without a question, so here goes...

When quaddy was returning home it was doing everything by itself except for the throttle, even though alt hold was enabled. My throttle was on 1512 and within the 20+- tolerance, but on this setting it was climbing, so i had to reduce the throttle by myself and then increase until it was back home. Is this something to do with the THRO MID or THRO EXPO?

Thanks to you all, have a good weekend,

xx

[dean19794]

Hey smilier

Sounds like you had a great day.. I';m in the process of learning to fly also I had a quad at first x450 with AIO pro with GPS... Love the RTH switch makes you look like a real pro.

I';ve got a full carbon hex now running the same gear...

Watch this video: Tarot FY680 in the office on Vimeo

Little link to a video off my gopro.. You got any vids of yours yet??

Where do you fly where';s your club I';m just field flying at the min.

Hope I get to fly this weekend..

[bunnygirl80]

I didn';t take my video camera with me today! The only movies I have online are here..

20130113 Quaddy First Outing

That was two weeks or so ago.

[Gaza07]

The barometer on that board isn';t very accurate its the bmp085 and if you can get it to hold altitude around 1m then thats about as good as it possibly can be, your new AIOP has the newer ms5611 baro and will do a much better job 

[bunnygirl80]

The barometer on that board isn';t very accurate its the bmp085 and if you can get it to hold altitude around 1m then thats about as good as it possibly can be, your new AIOP has the newer ms5611 baro and will do a much better job 

Hi Gaz, Yeah, I kinda got the bit about it not being accurate, but at the moment the alt hold doesn';t seem to be kicking in at all. Are there any pre-requisites sort of speak, like the throttle stick on the tx has to be in a certain position, the throttle mid etc? any setting up to do? Thanks.

p.s. Was the code okay in the end?

[Ross]

MAYBE it was the actual aerodynamnics of the Quad that caused it.  Many modellers never seem to  look into that side of things and assume it';s the electronics etc.....Various shapes have different effects on aircraft.  Not a lot you can do about it with these machines  I suspect, (as opposed to a fixed wing job).   Some you win..some you loose?  Annoying tho';

[guest325]

Just a thought on the baro, mine has some gauze on top of it - I think it helps buffer the sensor from wind changes; could it be part of the problem?

[Ross]

Ref Darryl';s comment.  I was looking around for some decent "sponge" to place over a barometer and found that the black type that is packed as anti static packing allows the pressure through no problem at all, yet shields the baro from downdraught. There are different thicknesses available and Rapid, RS and Farnells sell it.
As I handle a lot of opotelectrics I get it in squares 60mm x 60mm and 5mm thick   as part of the packaging.

[bunnygirl80]

Hi guys,

Well, the weather looks good and I';m off out for some airtime this afternoon - just after my bacon and egg butty!  ;D

I';ve just added a piece of that sponge to see if it makes any difference. I have lots of it too! If it';s any good, I';ll be taking orders. By the way its £0.25 per 1cm square professionally cut with my kitchen scissors! LOL.

Will report back later, perhaps even with a video!  ::)

Thxx

[hibbo]

Hey Stef - I';ve been trying to get my quad to AltHold to a reasonable degree and have stumbled across this:

My easy Alt Hold setup procedure based on actual 2.1 average algorithm:

1-Put zero on Alt P and Alt I. Then play with D (in reality D term represents the proportional accelerometer influence over thrust) and trying to find a sweet spot where copter maintains altitude on short term. You know you got a good "D" value when pushed down or up, the copter reacts instantly to your change and keeps its altitude. Unfortunately, there is one single proportional term to this loop, so it is less perfect than it could be (PID).

2- After finding the sweet spot accelerometer response D, any other influence on thrust like baro (P, I) would make the copter overshoot. So we need to lower a fraction of D and complete the response with Baro PI loop. My sweet spot of D is 15 and i lowered it to 7. You could try some 50 to 80% from the initial D find, my opinion is that D should be more than half.

3-Now leave alone the shrinked D (I=0 during this time) and start increase P term until you got altitude BIG oscillation with an continous increasing amplitude . When you got altitude self increasing oscillation, half the P. Now the copter should hold its altitude in a range of about 1 meter because the P only term loop can';t fix the altitude error exactly.

4- Leave alone P and D found as described above and increase I term until the copter stays in a range of 20 cm up or down. 20 cm is the noise of inflight baro MS6511. That';s it.


Note:
The 20cm result is valable using MS6511 baro.
The baro shoud be protected by direct sunlight and direct wind.
All test below must be made at an altitude higher than 1.5 meters to avoid ground effect.
All tests should be made on a calm weather.
Blutooth data connection with GUI is invaluable for graph visualisation of Baro pressure or even inflight parameter settings as i did. I let the copter on GPS Pos Hold howering above a field and i played with the parameters from my laptop.

this is taken straight from here: http://www.multiwii.com/forum/viewtopic.php?f=8&t=2371&start=40

I know it';s for a different Baro but it should still make the AltHold a little tighter.  I';m going to try this tomorrow if the weather holds 

[bunnygirl80]

Hi hibbo, Thanks for that. I';ll give it a try to see if it improves anything. Thxx.

[hibbo]

Happy Sunday All

Just been playing around with my Altitude PID settings in MultiwiiGUI.  This is inside as it';s snowing and raining and just pretty rubbish outside.

Well I followed the above instructions regardless that it';s for a different Baro and have ended up with a really stable hover.   Of course it';s not deadly accurate but it';s way, way better than it was. 

These are my new settings for Altitude;      P-0.3      I-0.001      D-7

That';s quite a long way off the original P and I settings, but just goes too show that these boards aren';t exactly "plug and play"

If you';re interested these are my PIDs so far -

[bunnygirl80]

Hi hibbo,

Thanks for that. After comparing our figures, I notice there are a LOT of differences. I think this just proves how different each quad can really be. My quad hovers and flies beautifully and this weekend I';ve put in another six flights and only put minor changes into the PIDs. If I push down on the quad when it';s in a level flight it really responds nicely in auto correcting to level. One thing I haven';t done yet is play with the PIDs for the other function. Anyway, here are mine!

Thxx