Replies to This Discussion

Permalink Reply by Harry on June 5, 2012 at 9:15am

I'm interested in how your tuning goes, but your logs are blank for me.  Maybe you could post them as a screenshot or something?

Permalink Reply by Andrew Brygin on June 5, 2012 at 10:37am

Oh, sorry for the mess, I have converted logs to pdf.

Attachments:

• LOG00220.pdf, 75 KB
• LOG00221.pdf, 74 KB
• LOG00222.pdf, 83 KB

Permalink Reply by Harry on June 5, 2012 at 8:13pm

Thanks, I can see it now.  I wont be much help to you as I am learning, but I will need to tune mine when it goes airborne.  Just a thought but is the IMU level when it boots up?  I can see the bias toward the positive side.  Hope you dont mind I made a shot of the 220 log.

Permalink Reply by Andrew Brygin on June 6, 2012 at 1:15am

I keep IMU leveled during initialization, and oscillation in case of LOG220 were clearly visible, so I think that roll readings provided by th IMU are close to truth.

I did a test with increased I gain, and it looks quite positive: I keep P gain the same as for LOG00222 (0.0015) but set I gain to 0.001. LOG00223 shows quite good match of the roll value with navigation roll for first 10 minutes of the flight.
However, after that time, the tendency to fall into the left spiral have returned. I guess it can be explained by a decrease of air speed due to battery voltage drop (I keep throttle level the same during all the  flight).

To check whether this guess is true, I will try to draw the log of the air spped.

Attachments:

• LOG00223.pdf, 57 KB

ModeratorPermalink Reply by Brian on October 4, 2012 at 7:54pm

how did it go with your project. it has been a while.

Permalink Reply by Andrew Brygin on October 12, 2012 at 2:54pm

Hi Brian,

 thanks for the interest. I had achieved acceptable level of roll and pitch authority in FBW mode, and RTL mode worked acceptable too. I even created a some sort of diy OSD to visualize the AP output (startd text GCS) during fpv flights, see A screens shot:

However, the end of the story is a bit sad: I lost the plane and all equipment due to UBEC failure: I have totally lost control over the plane and OSD frost (due to absence of AP output) about 3 km avay from the start point. Camera and VTX keep working, because they were powered directly from the battery, and I had a chance to see the final spiral of my X-5. Unfortunately, I failed to found it.

A good part of the story is that I made a step forward after it: now I am playing with X-8 and APM 2.5 :)

Thanks,

Andrew

Permalink Reply by Charles lakins on October 11, 2012 at 3:54pm

aslong as the imu is facing forward any angle it is calibrated will be its level point and change from there after and reflect the movements the same

you can verify this by attaching it directly to the ftdl port and by using arduimutest.exe

the plane will always be level after inital calibration .

however the sides and front will be swapped if not facing forward atleast