AutoTune, Motor Turn Off and Misc questions

Just autotuned my 20lb x8 and mid size quad. 6s batts on both, 14, and 15" props. Have a few questions…
I am not looking for high performance flying. Just easy flight for filming and steady in higher winds.

  1. Autotune has an aggressive, medium, and weak setting. Is the medium a "detuned " aggressive and does it take as long to auto tune.

  2. If I save the autotune settings and do a 2nd or 3rd auto tune, will it start from whatever my current settings are? Is doing multiple autotunes like fine tuning the previous autotune?

  3. I set the rate roll and pitch filters to 10 hz as suggested for larger MR’s. After autotune, do I leave the settings at 10hz or change back to the default of 20hz.

  4. When I land, I hold the throttle down, switch to stabilize mode and it takes about 6-8 or more seconds to shut the motors down. If I put both sticks to the right to shut off while in alt hold, it flips the quad. I’d like the motors to shut down if I have the throttle all the way down withing 3 seconds or so. Afraid to program a cuttoff switch in case of inadvertently hitting of said switch. Any suggestions.

  5. For failsafe or RTH, I just want them for loss of radio contact, not low battery. Which settings do I need to enable. Do I need to set throttle levels or anything else? I do want verbal low battery warning for mission planner, but not auto RTL or auto land.

  6. I’m currently using the 3DR 915hz telemetry setup. Any suggestions for a better (longer more stable reach), setup without breaking the bank.

Thanks for any suggestions or hints.

I don’t have answers for your autotune questions but I do for the others.

.4. You only use the rudder/yaw stick for dis/arming. Switch to stabilize and hold in bottom left for safe quick disarm.

.5. Go into Initial Setup>Failsafe. Change battery to “disabled”. Change radio to “enabled always RTL”. You need to set your radio throttle failsafe to a value lower than the FS PWM value to trigger the FS. Set GCS FS to whatever you want. You can set verbal battery warning in Initial Setup>Battery Monitor page, “MP Alert on Low Battery”. It will ask for waning voltage setting.

.6. These are excellent Telemetry Radios.

  1. Thanks, I not a big fan of landing, switching to stabilize, then holding throttle down left. But it’s good to know it’s just the one stick. That is faster than leaving the throttle down for the 6-8 seconds.

  2. Flying yesterday, my buddy showed me the rf900p modem bundle. I don’t need anywhere near that distance, but assume the two antenna setup for going out maybe 1/2 mile or 1 Km would be rock solid.

  3. I have the first battery FS set to disabled and the radio set to enable always rtl.

But I need a bit more help on this part. “You need to set your radio throttle failsafe to a value lower than the FS PWM value to trigger the FS. Set GCS FS to whatever you want.” Right now I’m using Futaba 8fg and hopefully will setup a old Taranis 9xd that I bought and never used.

Thanks for your help.

Thanks. I’ve read many of the documents, but hadn’t read that one. I’ll dig into the futaba manual and see if I can’t figure it out.

Strange as it may seem, I’ve have 5 mr’s I’ve built plus a couple Inspire 1’s and a mavic. Think I’m in my 4th year of flying and I’ve never tested RTL or RTH except checking settings through the software.

I had it invoked one time flying over a lake in my inspire when the battery go low, but canceled it within a few seconds as I thought I had a fly away. Manually land it without issue. Recently, on the Pixhawk 2.1 during setup, it did the same on low battery (which I’'d set to high) as I was doing a bunch of short test flights manually tuning in my back yard. Again, cancelled that within a few seconds.

Never the less, I don’t like those few seconds when I lose radio control… Someday I should probably turn off my radio when in a wide open space and test RTL.

Thanks again for the link

Autotune.You need to switch out of autotune and back into it,then land and disarm in that flight mode for the settings to take.A thorough read of the method is recommended.

When the tune completes the copter will change back to the original PID gains.

Put the ch7/ch8 switch into the LOW position then back to the HIGH position to test the tuned PID gains.

Put the ch7/ch8 switch into the LOW position to fly using the original PID gains.

If you are happy with the autotuned PID gains, leave the ch7/ch8 switch in the HIGH position, land and disarm to save the PIDs permanently.

If you DO NOT like the new PIDS, switch ch7/ch8 LOW to return to the original PIDs. The gains will not be saved when you disarm.

If you save the values set then it will start from them on the second autotune.The second tune will be quicker and should nail it down better.I’ve just posted a video of a second AT with a big hexacopter using 3.5.0 firmware.I’ve just kept the values it flies so nicely.

Jagger… thanks. I know that is how to save or not save the auto tune settings. I wanted to know if when you do a follow up autotune, if it starts with your new saved (previously saved autotune settings) and thus would be quicker at the autotune and be more of a fine tuning or checking your other numbers.

I saw your posted video earlier. I’m going to try another autotune with relaxed settings, aggressiveness .05 ( as discussed in the comments on your video). I might even try the position hold autotune as I can do that in my back yard if it doesn’t wander to much. I’m also going to try your compass cal method I saw on youtube. Interesting.

I’ve done a couple autotunes and like how my 725 mm quad flies with 3520 / 400 Kv motors flies. Hopefully today, I can do some more autotunes on my 900mm x8 w/ 3515 400 Kv motors. Tuning at about 17-18 lbs with extra weight, but with gimbal, it is more like 19-21lbs depending on camera. Hope it is as smooth and quick as your just posted video.

Thanks for your comments.

I’ve run 4 autotunes on that copter now and they get quicker and quicker.The PIDs are all reducing from the first tune.The 0.63 is down to 0.52 and the 0.49 is down in the mid to high 0.3x.It doesn’t feel too different and still handles nicely.

Also - throttle/radio failsafe is easy enough.My Taranis has a low reading f around 985 PWM so I set the failsafe for below 975 and always RTL.That way,if I turn the radio off it just comes back to the launch point and lands itself.

Since i did not want to open a new post since my questions might be relevant.
Reading it does say about switching ch7/8 from high to low to test PID or fall back to old as also that you need to do on ALTHOLD or LOITER, i dont understand though from the doc that it says you should land on that specific mode in order for them to be saved. Since i had lately an accident with the Octa flipping on land since it did not racognize it landed (maybe due to ground effect), are you sure that they will not be saved if i leave the Autotune switch on High and i flip to stabilize in order to land?
Also, could you explain to me (if you know) how big of a difference is to autotune a 16" octa with filter set to 20 instead of 10? since my first autotune was done like this and PID values on logs seem to be almost perfect on top of each other. Maybe i should do again starting from existing PID with filter set to 10?
Edit: in the Autotune wiki it states: Be advised that AutoTune will engage from Stabilize, so don’t accidentally flip your AutoTune switch until you are in AltHold and ready to begin the procedure. This means it will also land on Autotune and stabilize and save values? @rmackay9 have i understood something wrong?