Go Home Problem, Please Help

[multi-prop-chop]

HELLO! Fellow multi rotor-heads.

I wonder if anyone can help with my Wookong M. In short, my Skyjib 8 flys great almost all of the time. However, maybe 2 out of 10 times that Go Home is activated, instead of the normal controlled and gentle Go Home landing, I get an almost immediate circling behaviour, as if the heli cant quite get over the home-point and eventually after circling it, it will actually try and land whilst circling at quite some speed, which of course makes for a dangerous and scary landing. FYI I never take off without having a full gps lock and the heli flys in both atti mode and gps atti perfectly. Only when I switch to GO-Home do I see this circling.

Any thoughts much appreciated.

Prop-Chop

 

[Dewster]

I had that happen to me once. RTH worked fine when I tested it and the day I tried to demo the feature to my wife it started that crazy orbit you experienced. RTH worked. It was on descent that a small gust of wind hit the craft and threw it off its home point. My craft kept hunting and pecking in a circular spiral as it tried to establish its landing point. It would start as a small spiral outward and grow to a larger one before returning back to a small spiral during landing. It's like it would find its home point, but the momentum would take it past it causing it to hunt for the point again (threading a needle with thick string).
RTH only did that once for me. I just use it to bring the craft back to home and retake control to land it. I have a Y6 and don't want to risk damaging props. RTH worked 99 percent of the time with my quad in landing on a dime. That one time that it didn't was scary.

Solution- Switch flight modes once the craft hovers over home point to interrupt the landing sequence. I switch from GPS to Attitude and then back to GPS. Be careful of switching it into manual mode. You might get unexpected results if you have never flown in that mode. Most importantly, make sure that your craft has recorded its home position before taking off.

 

[multi-prop-chop]

Thanks Dewster, your description is bang-on. Like the heli's momentum made it over-shoot so it kept spiralling, over-correcting and so on. But why would it do this?


Paul

 

[rexbirk]

Could this be an issue with the gain settings and is being set off by wind conditions?

 

[Dewster]

Thanks Dewster, your description is bang-on. Like the heli's momentum made it over-shoot so it kept spiralling, over-correcting and so on. But why would it do this?


Paul

I have no idea. It may be a couple of factors: The craft's balance, build, wind, GPS strength. How does your craft hold in GPS mode? You should have a rock solid hold without the " toilet bowl" effect before you use the RTH feature.

I use the RTH for recovery and land it myself. I would like to record a Home position and then physically transport the craft to another location, launch it and see if it'll fly back to its recorded home position. It would be great for automated camera shots. The craft will fly a direct path home. You just have to make sure you have enough altitude between launch point and home point. Trailing...

 

[Dewster]

Could this be an issue with the gain settings and is being set off by wind conditions?

I don't know. I do know that one set of gains affect how the craft stabilizes itself and the other set of gains control how it responds to your control inputs (abrupt/soft transitions). I imagine that adjusting the right gains could have an effect on how quickly the craft stabilizes after being upset. That could result in less hunting and pecking for it's home position during RTH descent.

 

[multi-prop-chop]

The skyjib hovers rock-solid hands off in the hover. Only does this on go-home. It's balanced well and the gains are seem fine for any other time?

Thanks for the help so far.

Chop