Course Lock --- first impressions

[ianwood]

I haven't tried this yet on the P3. On the P2, course lock works differently in GPS mode vs. ATTI mode. In GPS mode, CL holds the actual course using GPS to adjust for drift. In ATTI, it doesn't.

It sounds like from the mix of reports here that both may be possible on the P3 but maybe engaging them is not as clear? It would be very disappointing if you couldn't use CL in GPS mode. CL in GPS pretty much negates the need for independent gimbal movement and two man operation except in the most challenging of circumstances.

 

[Kenneth Gundersen]

Are you sure you put the switch to F and not A? As in the Atti mode (A) the P3 will drift with the wind. It should not drift in courselock (F).

 

[Bret Lucas]

Interesting, the manual states nil GPS during CL, but I've experienced no drift during CL.

 

[Volkhard]

Interesting, the manual states nil GPS during CL, but I've experienced no drift during CL.
View attachment 26320

Bret

Try what I did during low / moderate wind:

Set a course adjacent to a a straight line (a street) with cross wind perpendicular to your course.
Fly forward under Course Lock for about 300 to 400 meter with your control just forward (resist the urge to correct) stay in Course Lock and fly back the same course. Again strictly pulling the stick back without any compensation/correction. Please do so in safe altitude above any obstructions!

You will end up more or less (depending on the wind) in lee of your starting point.
If this function would use GPS it would compensate for the wind drift and this exercise would bring you back more or less to your origin (within a foot or two for possible GPS inconsistencies).

If your Phantom 3 acts like mine you will have a wind induced offset to lee, flying this exercise.
The first time I tried Course Lock (standing behind the Phantom, so forward was really forward) I found myself "automatically" compensating a little to windward. (old habit from decades of RC flying).
I have a bunch of powerlines and powerpoles on "my"street in front of my house so I have to pay attention!

The I tried again forcing myself not to compensate and the result was the offset to lee by about 4 to 5 meters after flying back and forth on Course Lock.

The weekend is coming up. Perhaps others can do this exercise with the crosswind perpendicular to the set course and report back their findings.

 

[snowghost]

Interesting, the manual states nil GPS during CL, but I've experienced no drift during CL.
View attachment 26320

Maybe it means that in CL GPS doesn't matter. So it works with and without a lock. Whereas HL would always need GPS.

 

[ianwood]

Course Lock by it's very name should hold a course. Unlike simply following a heading, holding a course includes compensating for drift. Which would require GPS. Otherwise it should be called Heading Lock.

 

[4wd]

What happens if you select course lock without enabling the mode in the app first?
Presumably it goes in ATTI mode. Just wondering...

 

[steves]

Good morning,
All this talk about course lock has me very confused. So I had to go out this morning and try. Made all the necessary settings to obtain course lock, Took off lined it up to my street and flip the switch down two notches. There it was course lock with GPS. Just to make sure Flip the switch up one notch and it started drifting like crazy. Perhaps your compass is not calibrated correctly so you are really not flying in the straight line. Mine works flawlessly, by the way I'm still on 119 I will not upgrade until they get all these problems ironed out. I hope this helps someone
Have a great day

 

[snowghost]

Good morning,
All this talk about course lock has me very confused. So I had to go out this morning and try. Made all the necessary settings to obtain course lock, Took off lined it up to my street and flip the switch down two notches. There it was course lock with GPS. Just to make sure Flip the switch up one notch and it started drifting like crazy. Perhaps your compass is not calibrated correctly so you are really not flying in the straight line. Mine works flawlessly, by the way I'm still on 119 I will not upgrade until they get all these problems ironed out. I hope this helps someone
Have a great day

That is what I thought would happen. When it says in the manual "GPS Counts" I think it is a bad translation of whether or not GPS matters or is necessary in that particular mode. Therefore course lock works with or without satellites. Whereas home lock by its very definition would have to have GPS working.

 

[duse500]

Good morning,
All this talk about course lock has me very confused. So I had to go out this morning and try. Made all the necessary settings to obtain course lock, Took off lined it up to my street and flip the switch down two notches. There it was course lock with GPS. Just to make sure Flip the switch up one notch and it started drifting like crazy. Perhaps your compass is not calibrated correctly so you are really not flying in the straight line. Mine works flawlessly, by the way I'm still on 119 I will not upgrade until they get all these problems ironed out. I hope this helps someone
Have a great day

Same test here,same results,same FW

 

[TeeJayN]

Perhaps why some are seeing GPS control during CL and others are seeing drift during CL might have to do with what version software they're on? i.e 1.19 vs 1.26?

 

[Volkhard]

I have not upgraded the Firmware therefore : 1.1.9. I did some additional test flights this afternoon with the same results.
Flying on CL with cross-wind offsets slightly to lee when flying down the path and is offsetting again to lee when flying back the same path. Stick movement strictly for and aft; no correction.
Offset is not dramatic but adds up to about 5 meter on a path distance of ~ 300mm (total flight 300m forward + 300m backwards = total of 600m)