Servers by jDrones

Behaviour following a loiter

(Justin) #1

I did a loiter in my fixed wing and I set my next waypoint to be 300m higher. This next waypoint was several km’s away. I wanted the aircraft to gradually climb to the next waypoint over the distance of the leg. However I noticed the aircraft climb aggressively after the completion of the loiter to get to higher altitude. Is this normal behaviour following a loiter? If so, I will need to set another waypoint after the loiter at the same altitude before it commences the gradual climb.

Thanks, Justin

(lucamax) #2

It is not a normal behavior if you did not change the standard parameters.

If I remember well altitude changes within 20 meters are immediately executed while for larger changes the AP calculates a slope.

(Justin) #3

Great info thanks. You actually answered another question that I had regarding the plane suddenly increasing height between two waypoints that were close together and the height difference being less than 20m.

One other piece of info, I did not include in my question was that the altitude the plane was at was -200m flying to +100m relative to launch. I was flying over some low elevated ground. Not sure if this played a part.

Another factor could be the fact that I had lost telemetry and may have lost rc signal due to some strange interference i can still not explain. Possibly a nearby radio station.
I am analysing the logs now.

(Justin) #4

I will upload bin file, however it seems to get to 7% and then stop.

(Greg Covey) #5

Hi Justin,

The .bin files are too large for this site so people typically host them offsite and put the link here in a post.

Another technique to change altitude is to use LOITER_TURNS in your mission plan. Enter a second LOITER_TURNS after the first one and change the altitude with a reasonable number of turns to reach it. Then go on to your next waypoint. You can use it like a circular staircase…going up or down.


(Justin) #6

What a great idea! I’ll have to give that a go. Thanks.
Are you able to give me an example of the other site that people use for their .bin files?

(Greg Covey) #7

A popular free one is Dropbox. I have used YouSendIt in the past but host my own site now. Try this 2013 article below.

The Best Free Programs and Online Services for Sending and Sharing Large Files


(Justin) #8

Thanks for your help Greg.

(Greg Covey) #9


I ran across my video of the FireFLY6 VTOL mapping survey where I changed the landing technique to use Loiter Turns to descend before transitioning back to Hover mode. We used the Hoodman Landing Pad to show how accurate the take-off spot is to the landing spot. The swirling winds gave the Wind Assist feature a good test as well.

In the Mission Plan image, you can see the LOITER_TURNS entry twice. The first entry is for circle location at your current altitude and the second entry is the same location but with the desired exit altitude. The circle count of 3 is the amount of rotations needed to easily obtain the desired exit altitude. The FireFLY6 Planner differs slightly from Mission Planner but the idea is the same.

(Justin) #10

Hi Greg, thanks for the video and demonstration.