Re: [Paparazzi-devel] Another day at the flying field...

[Gerard Toonstra]

This morning made another test in stabilized mode. The new gains and max. angle settings really help to make the flight feel more comfortable. 
The only issue I still perceive is a thrust angle misalignment. When throttling up a lot more, the nose is pushed down quite a bit, which makes the elevator work
a lot harder and some up trim is necessary to achieve level flight. It also tends to bank right a little bit, but I think I can correct that by a very slight
angle of the motor to the right, because there's quite a bit of torque involved.

All radio glitches disappeared after increasing the boundaries of the radio a little bit (1920 -> 1940, 1080 -> 1060), so around 8 circuits were made in stabilized
flight without glitches. In the next test I will verify the new throttle/pitch behavior, the bank angle and probably attempt to flick into AUTO2 mode to see it
go into a STDBY circle.

Rgds,

Gerard

On Thu, Feb 28, 2013 at 12:22 AM, Gerard Toonstra <address@hidden> wrote:

Hi Stephen,

See other messages. Non-actioned flight plan, just caught off guard by the behavior, but this only happened once (first time). 

Good point about gains. I used Tobias's twinstar example, but upped the gains for the servo's and probably come out twice those 

on a model of 2.5kg or so. This should be a lot better for control tomorrow.

G>

On Feb 27, 2013, at 10:32 PM, Stephen Dwyer <address@hidden> wrote:

Hi Gerard,

Did you make sure you either manually enabled throttle or entered a flightplan block that enabled the throttle before switching to auto1? If you don't enable the throttle (throttle in strip is red when disabled), you will see that behaviour (happened to me the first time I went into auto1 as well).

I assume by "good settings for how the control surfaces react to offsets in roll/pitch" you mean a well tuned inner stabilization loop? Note that default settings were probably from a Microjet, which is very agile and probably doesn't need such aggressive gains. We had to bump ours to double default with a big Telemaster. I find a good method for tuning the gains is similar to what is described on the tuning page. Plot in realtime and watch the overshoot and time constant, and adjust using typical PID tuning methods similar to those described in the Wikipedia page. An example of data before and after tuning the roll loop can be seen at the end of this video. A second person to operate the GCS while the first flies is very useful for tuning.

Thanks,

-Stephen Dwyer