Replies to This Discussion

DeveloperPermalink Reply by Randy on March 11, 2012 at 10:56pm

Yusong,

     Can you try increasing your Stabilize Yaw P value?  I think that should make it move more.

     If you're having problems with it maintaining a heading, you may also want to increase the Stabilize Yaw's I term and/or the IMAX.

     hope that helps.

    

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Permalink Reply by Yusong on March 11, 2012 at 11:15pm

Thanks Randy for so quick reply! I will try tmr and report back.

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Permalink Reply by Yusong on March 11, 2012 at 11:31pm

Besides Randy, I tried to ask in another thread, that how to arm the helicopter? I tried to hold the throttle stick to the lowest right position for a while but it did not seem to work. How to I observe it is armed without a laptop connected? I want to be able to set the lift off location as the home location for RTL.

Thanks!

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Permalink Reply by Yusong on March 13, 2012 at 6:12am

Randy, I tried and STB_YAW_P did make it move more. I can move the rudder and the servo travel is full. However, when I rotate the heli itself the servo will travel in a very limit range which is impossible to hold the tail in flight. I have messed with the parameters but could not figure out which is the right one.

And if I choose to use the gyro, even if I tune the gyro gain down to 0, the servo will still swing very big and the heli will shake widely on ground. Could not lift up.

Do you have a set of parameters that you can recommend? My current values are:

RATE_YAW_D	0.002
RATE_YAW_I	0
RATE_YAW_IMAX	5000
RATE_YAW_P	200

STB_YAW_I	0.001
STB_YAW_IMAX	1500
STB_YAW_P	20

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DeveloperPermalink Reply by Randy on March 13, 2012 at 6:59am

Yusong,

     I've always used an external gyro so I'm not sure what are good values for the yaw servo.  It might be better to ask on the monster trad heli thread.  I'm sure Robert doesn't use an external gyro any more.

     I guess my advice would be to try setting the stabilize yaw (i.e. STB_*) to zero and then use the channel 6 knob on your transmitter to dynamically change the RATE_YAW_P to a value that mostly keeps the tail from moving to much.  Of course to do this you need to have a channel 6 knob on your transmitter and have it wired up to your APM's input channel 6 and then finally you need to use the APMP's configuration screen and on the bottom right set the drop down to  CH6_YAW_RATE_P and then set the two values just below to 0 and 2000 (or 1000 x the max value you want).

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Permalink Reply by Yusong on March 13, 2012 at 7:18am

Perfect. I don't mind using a external gyro. And yes I will try to see if some one over the 600 heli thread has any advice.

I use a copterx 9x tx (turnigy oem) so yes I have free channels that I can use. I will try your method tonight and report back. I did not realize that you can adjust the parameter values using tx on the fly at all, this will be very helpful.

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DeveloperPermalink Reply by R_Lefebvre on March 14, 2012 at 1:49pm

Yusong, I don't use an external gyro, I don't even own one.  

I'm using Rate_Yaw_P of 0.350 and STB_Yaw_P of 2.  I don't remember the other numbers off the top of my head.  You don't need to see the tail servo moving over the full range on the bench.  It doesn't need to.  That's for 3D manoeuvres, which the system is not intended for.

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