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at every waypoint 540 degree yaw

PostPosted: Fri Dec 14, 2012 10:40 am
by rwijnhov
Ok I got my quad flying really nice at the defaults pids. So now i am back at flying missions again. I get some weird behaviour. Whenever the quad reaches the waypoint it will do a 360 yaw. then wait for a small moment wil start flying and emidiately do a 180 yaw and goes to the next WP. It does this on all WP.

Re: at every waypoint 540 degree yaw

PostPosted: Sat Dec 15, 2012 2:34 am
by chris24g
that is beacuse it is pointing to the heading it was set to. most likely 0 degreees, so it will go to waypoint, then point north, then turn toward the next wp

Re: at every waypoint 540 degree yaw

PostPosted: Sat Dec 15, 2012 10:17 am
by rwijnhov
How do i get it to not do that?

Re: at every waypoint 540 degree yaw

PostPosted: Sat Dec 15, 2012 11:33 am
by JussiH
Negative values for wp heading will cause this behavior - minus defines a heading relative to the WP, so when you reach the WP, the copter will "hunt" around that Waypoint.

Re: at every waypoint 540 degree yaw

PostPosted: Sat Dec 15, 2012 12:37 pm
by rwijnhov
Ok what do I enter then to solve thuis? -1.0

Re: at every waypoint 540 degree yaw

PostPosted: Sat Dec 15, 2012 3:42 pm
by rwijnhov
Ok found out it is my yaw overshoot that is causing the issue. I have mayor yaw overshoot. How do I tune this. in the wiki it says tune yaw angle D but I think they mean yaw angle D. So how do i tune overshoot?

Re: at every waypoint 540 degree yaw

PostPosted: Sat Dec 15, 2012 4:18 pm
by JussiH
Overshoot is usually caused by the yaw angle you command by can not be reached fast enough - you can either tune rudder factor down or increase the max yaw angle allowed.

Yaw angle OM limits the maximum yaw angle and is expressed in radians per second (1radian = 180 degrees). So the 1.25 default equates to 225 degrees a second. You may also need to allow higher Rate PM and OM, and slightly higher rate P to allow the motors to keep up with commanded input.

-1.0 in heading means that heading is relative to waypoint - so unless you program a second waypoint with absolute heading (0 to 360 degrees) to be exceuted on arrival, you will get the hunting behavior and sometimes it will prevent further execution of the mission. I avoid relative heading and plan missions with extra waypoints to make sure headings are correct throughout.

Re: at every waypoint 540 degree yaw

PostPosted: Sun Dec 16, 2012 11:02 am
by rwijnhov
Edit
completely back to stock and on r49.

Re: at every waypoint 540 degree yaw

PostPosted: Mon Dec 17, 2012 11:31 am
by rwijnhov
Ok I guess i am on to something but not sure on how to fix it. As soon as my craft reaches a waypoint it wil start yawing. Same happens with rth. As soon as it reaches it rth position the craft will start yawing there without end. So that is also what is happening with the WP I guess. IN normal hover and alt hold no yaw. SO why yaw when on auto mode or RTH?

Re: at every waypoint 540 degree yaw

PostPosted: Mon Dec 17, 2012 12:43 pm
by sandmen
@rwijnhov
can you post your missions, or send me per pn?
And how do you plan the missions?