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DeveloperPermalink Reply by jasonshort on July 31, 2012 at 10:31am

can you post your parameter list and a flash flight log downloaded from the APM?

Jason

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Permalink Reply by Tim Powell on July 31, 2012 at 10:17pm

Check your radio calibration.  If minimal throttle is acting like full throttle you might need to recalibrate.

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Permalink Reply by Francois du Plessis on August 1, 2012 at 6:40am

Tim

Thanks, we have looked into that and it does not seem to be the problem.  But, I am open to suggestions if we are missing something.

Jason (and Tim)

I have attached the log file and the parameters list.  The log file was recorded for the following sequence of actions with the system in stabilize mode.  The heli was mounted on a universal joint and being held level:

1. Throttle off
2. Throttle on 1 click going to full throttle to off
3. Throttle on 1 click with a +45 and then -45 degrees roll action applied. Throttle off
4. Throttle on 1 click with a +45 and then -45 degrees pitch action applied. Throttle off
5. Throttle on 1 click with a positive and negative yaw action applied. Throttle off
6. Throttle on 1 click with a random roll, pitch yaw  action applied. Throttle off

Thanks for the assistance.

Francois

Attachments:

• 2012-08-01 14-39 1.log, 166 KB
• Parameters 01082012 14-27.param, 4 KB

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Permalink Reply by Nicolas Garza on August 1, 2012 at 1:55pm

Haha, I was about to post the same thread as I have exactly the same problem, and almost your same setup (APM1.4 and DJI frame). I just reflashed my esc's with simonk's firmware and I thought that was the problem but it works fine if I hook up the ESC directly to channel 3 on the receiver, so the problem must be on the code (V2.7.1 Quad).

This is in every mode (stabilize, loiter, alt hold) except in acrobatic. In that mode the motors are fine, so my guess is I should change something in the stabilize PID's, but I haven't figured out which parameter yet.

I'll continue digging to see what I can find, but anyone's help is really appreciated.

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Permalink Reply by Nicolas Garza on August 1, 2012 at 2:13pm

Ok, for some reason the value of P in Angular Rate Control was at 0.185, even though the recommended rates are between 0.145 (for small motors) and 0.090 (for big motors) so that value was way off boundaries.  I assume the system was thinking we had super small motors and needed a lot of power to lift the craft. I changed the value to 0.145 as recommended and everything's fine now.

EDIT: FALSE! I was still in Acro mode when I was testing the results, so no, this is not the root of the problem.

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Permalink Reply by Nicolas Garza on August 1, 2012 at 2:35pm

The Stabilize Control P seems to do something with it. I change the value from 4.5 to 0.45 and the motors slowed down, but they were still too fast. I lowered the value to 0.001 and the motors slowed down a little bit more, but it remains too fast as well. And I don't know how much will this value will affect the performance of yaw, roll and pitch so I hope the answer is somewhere else

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Permalink Reply by Francois du Plessis on August 2, 2012 at 9:00pm

It seems like we have sorted out our problem.  I am not sure which one carried the most weight, but we are flying.

The first thing we did was to reset the APM board via the CLI interface as we were not getting any control signals when we tilted the quad by hand.

The second thing we did was to reset the ESCs.  It seems like we messed up the ESCs and put them in a wrong configuration during calibration.

Thanks for the assistance to those that offered it.

Francois

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