Autopilot/Mission Questions and Tip request

[Noxxid]

Hi, this is my first post here after stalking the forums for a while. I fly an Inspire 1 and recently acquired litchi. I have been flying for about a year, starting off with my friend's phantom and moving on to the Inspire. I feel very comfortable as a pilot and am capable of not panicking if it goes into Atti mode and I suddenly have to compensate for wind or some such. We usually fly a two man op where one person mans the camera while the other flies the craft. Unfortunately my partner cannot always be there. I am playing with autopilot and have a hard time surrendering control of my baby to software.

Questions:
1) How much can I trust autopilot software? How does it handle low altitude (very slow speeds maybe 10-15 feet agl through multiple waypoints)? Im flying over a lake, how likely is a sudden loss of altitude due to software/gps error? Is there anything that can reduce the likelihood of altitude loss?

2) Is there any way to have gimbal control from the master controller? Ideally id be able to set up one of the unused buttons to toggle (or while holding down) control of gimbal so if something went screwy with the autopilot I can instantly retake control and zip it to safety. Is my only option to set both controllers in front of me and risk not picking up the master controller in time?

3) Accuracy -error protocol: I know that I can set features like Return to Home if I lose controller signal or something but I wonder if there is a way with litchi or some software to set a sort of "oh ****" protocol if the craft detects an inconsistency/gps/compass error? Like -- all else fails elevate 100 feet-- since I know I have nothing above me at this location.

4) Any other information or tips on how to make this setup safe and effective is welcome.

Thanks in advance folks!

 

[GMack]

In Autopilot, I believe their "Emergency Procedure" is to flip the switch out of its running A-mode into P-mode that cancels the app and goes back into regular RC control so it should be quick. The odd one is the Phantom P4 where you flip it into S-mode to cancel and run via the remote control, if my memory serves me. They explain a lot of this in their "Flight School" manual, Section 3.

Evidently they talk of some learning mode where the app learns the mission flight's deviations due to wind etc, on subsequent flights and learns to fly the subsequent mission more accurately, but you have to be sure of the test route to begin with. They say winds over 10 MPH may impact the flight and cause curves or bows between waypoints until it learns to self-correct.

There is also some minimum "Safe" altitude in it I think set at 16 feet, although it can go to other "Unsafe Altitudes" all the way to -197 feet (Fwiw, they show 13, 10, 7, 3, 0 feet too, but all are listed as "Unsafe" so their thinking must be that 16 feet is okay with their app). I believe the default was around 26 feet initially.

They also mention that having the iPads/iPhones with the internal barometer may be more accurate than the GPS on the drone too. It's used for the Follow Me mode up and down elevations, etc.

Before trying it, you might want to fly the drone over a mile course without any autonomous app, just using GO, and see what the landing altitude is at compared to your take-off altitude of zero feet. It it is way off, say -100 feet on landing in the same spot, it might pay to address that matter (IMU cal?) before trusting the auto-flying apps, or add that 16 feet to the difference (i.e.116 feet.).

Good luck!

 

[Noxxid]

Thank you for the reply. Im unable to find any information on this "learning" mode. Can you elaborate? Also if Im not using follow me i am not sure why my phone matters.

 

[GMack]

Thank you for the reply. Im unable to find any information on this "learning" mode. Can you elaborate? Also if Im not using follow me i am not sure why my phone matters.

It's called "Adaptive Horizontal Power" in Section 4.4 of their Flight School manual under "Movement Parameters" that explains it.

Manual: Flight School - Autoflight Logic

As to the barometer, I believe it looks for that as the app's default before going elsewhere. I did see you can set the C1/C2 as a "Disengage" button too (Bottom of Sec. 4.9).

 

[Noxxid]

Thank you! Reading now.

**edit**

Oh this is for the Autopilot software which is iOS only. Does litchi/DJI Go use similarly adaptive software?

 

[GMack]

Thank you! Reading now.

**edit**

Oh this is for the Autopilot software which is iOS only. Does litchi/DJI Go use similarly adaptive software?

I dunno about Litchi and if it has adaptive learning, although it can be used on either system. I dumped Android since neither of my Samung's played nice with DJI GO due to video lag matters, reboots, ads popping up for coffee, software takeovers, plugging in USB cord to the RC and causing re-boots or restarts, etc. Samsung was a disaster for me and likely due to their included bloatware that keeps restarting and taking over resources even though I shut it down with Zapper or force app closures. Terrible OS system as it eats batteries too.

Reluctantly I moved to iOS (iPad Air 2 + Cellular) based on recommendations here and no issues. I was never an Apple fan, but I see it does have resource improvements. Autopilot seems more devoted to iOS with fewer operating matters than I got with Android software and GO. The Apple iPad's battery life is far better and surprised I can turn the iPad on the next day and it may still show 100% battery charge, where the Samy's drop to maybe 64% overnight.

I don't know how much of the OS that Autopilot uses, but it must be a lot. They told me they prefer the iPad Pro 9.7" over the iPad Air 2 for processing power with their app. The Pro 12" seems less powerful than the 9.7" model which I thought odd (9.7" fits the DJI cradle too - barely.). That app might be too much for Android to handle and why they haven't ported to that OS yet - or until Android cleans up their background resource matters that auto-start and eat into the processing power needed.