Question about IOC

[Greiswig]

Hi, all,

just crashed my Xaircraft Hex rather badly after losing control on an apparent flyaway. The stock Xaircraft GPS antenna was lost, and replacing it will cost about half what an entire Naza-M/GPS will cost, so it may be a good idea to buy a Naza, which seems to be more popular/reliable.

On th Xaircraft system, there was a "constant heading" setup that was very confusing to me: it would apparently make everything relative to a fixed compass direction. So if you happened to start out pointing due North, then yawed 90 degrees right, pitching forward would actually make it bank left, and head north. It was very disorienting.

I found myself wishing that it would instead act like I was the center of the universe, so that pitching back would always bring it back toward me, no matter what the orientation of the copter was. So in researching the Naza-M, I find this confusing bit of verbiage:

"In home lock flying, the forward direction is the same as the direction from home point to multi-rotor."

its pretty hard to tell from the words and diagrams, but this SEEMS to be describing what I am after. Is that true? So no matter what direction it is from me or where the nose is pointed, pitching forward moves the copter away from me, and backward brings it back?

Thanks!

 

[OneStopRC]

That is how I understand it too, but the unit must know where is flew from by using the GPS position on startup. One of the features I am interested in and will see very shortly.

 

[glacier51]

Greiswig:

Yes, that's what Home Lock is, if you have GPS.

Regardless of the nose direction, flip the IOC switch, pull back on the cyclic and the MR will fly back to the home point.

 

[mongo]

since i have never tried IOC with my naza, does that pull back, rth point, trick work after you have managed to get the copter behind you? probably never try it myself, but now curious.

 

[gtranquilla]

Assuming your MR records it's launch point and the pilot remains close to the launch point, RTH works extremely well and without risk of confusion.... just trust it to do the job!

IOC...... is quite confusing such that it may not always work as you might expect it to...... if confused or not well understood.... don't bother with it..... IMHO.

since i have never tried IOC with my naza, does that pull back, rth point, trick work after you have managed to get the copter behind you? probably never try it myself, but now curious.

 

[glacier51]

Mongo:

Another pilot posted a great description somewhere around here, but to paraphrase:

Once you have a good sat lock, at takeoff, NAZA records the "home position".

Then imagine a line drawn directly from that takeoff point to the MR, no matter where it is in relation to you or that takeoff point. Doesn't matter which way you're facing. When you trigger IOC Home Lock, pulling back on the cyclic commands the MR to fly back on that line to the recorded point, regardless of which way its nose is pointing.

Just think it terms of NAZA knowing where it is and where home is - it flies the shortest distance between two points. And since there's no real aerodynamic "front" on a MR, it doesn't have to turn, etc. to get the nose pointed back toward the takeoff point.

 

[Greiswig]

If it works that way, it will be a lot more intuitive than what the Xaircraft was trying to do! Thanks, all.

 

[mongo]

probably be a lot easier for someone who has not been flying r/c for 40+ years to wrap their mind around than it is for me. don't think i will be trying the IOC style anytime soon. do like the RTH on failsafe though.

 

[glacier51]

Mongo:
>don't think i will be trying the IOC style anytime soon. do like the RTH on failsafe though.

I hope you do give it a try. It's really perfect for noobies to multirotors and maybe that's what DJI was going for. Your MR's up in the sun and you don't know which way it's pointing? Switch up IOC Home Lock, pull back on the cyclic and it comes to you. When you see which way it's pointed Home Lock off and you're back in business. Really it's that simple.

Also I think it's actually a bit better than RTH because you maintain control if you're not out a ways on FPV. You have throttle control if you have to climb a bit and with the GPS working for you, if things start to break bad, just release the controls and it stops in a hover.

Regarding RTH, be sure to review the switches you have to reset to regain control if you don't want to autoland.

 

[tugboat]

I thought I had read something in the naza manual on distance regarding ioc (hm. loc & crs. loc.) as the craft gets within 20m it will revert back to attitude mode??
And yes it does work behind you BUT controls are reversed and its not advised.

 

[Dewster]

I thought I had read something in the naza manual on distance regarding ioc (hm. loc & crs. loc.) as the craft gets within 20m it will revert back to attitude mode??
And yes it does work behind you BUT controls are reversed and its not advised.

Agreed. If I plan on using IOC, I point my craft in the direction that I intend to fly. The controls are very easy. Right will be right ; left will be left regardless of which direction the craft is facing with IOC activated. Just don't fly your craft behind your Home position otherwise the controls are reversed. I found that out and almost hit a tree (lol). I had to use RTH to save my craft until I could figure out what was going on. IOC is great though. I flew my craft towards the horizon until it was a small dot in the sky. I brought it back when I couldn't see it anymore. You don't have to worry what direction your craft is facing.

 

[glacier51]

Morning:
I conducted a short flight this morning to look at Home and Course Lock.

I've never actually tried CL, but after reading the manual last night, my hexa does what the manual says.

Tugboat, the manual says it reverts at 10m instead of 20m like you said but I couldn't really judge the distance and it's really not that important. It's what happens when you're in HL and you hit the "circle".

With a good sat lock, I flew out about 30-40m, triggered HL and pulled back on the cyclic. The hexa came right back to the takeoff point, but when hitting the circle, it wobbled and then headed off in a different direction.

That direction was "backwards" away from the home point and recorded "Course Lock" azimuth. NAZA reverted to Course Lock entering the circle, so when I kept the aft cyclic control input, it started flying away from the recorded azimuth, which was about a 70-90 degree change in direction from the course it came back to me in HL.

Sorted it out by stopping in the hover, applied forward cyclic and the hexa flew "forward" along the recorded course azimuth.

I then when out in GPS/ATT along the recorded course azimuth, stopped about 40m away, turned left, flew about 20m and stopped.

With the nose pointing approximately 90 degrees left of the recorded azimuth, I triggered CL and pulled back on the cyclic. The hexa flew a parallel track toward me, but offset by the 20m, with the nose pointed off to the left.

After this flight, I can easily see how a pilot would get the controls mixed up while in HL if the MR comes within the "circle" and the pilot leaves HL engaged.

Ron

 

[tugboat]

Ron,
I could not agree more, I've only used hm. loc as I don't have a use yet for crs. loc, I like home loc because when the quad gets a ways away sometimes it's hard to tell the orientation and home loc works great for me in that situation...:02.47-tranquillity: