Landing Not Detected

[RoboMotic (AMV)]

Thanks!

About the “P”, yes, I have a payload on the landing gear, here is a picture of the drone.

For the PID, I have folow the excel shit (initialparameter.xls), and then the autotune, with a simulated payload, to avoid any damage in the process.

I have not made the notch filtering yet, we will do it ASAP.

[xfacta (Shawn)]

I would even test and tune without the payload at all then reduce these to suit:
ATC_ACCEL_P_MAX x (min_TOW / max_TOW)
ATC_ACCEL_R_MAX x (min_TOW / max_TOW)
ATC_ACCEL_Y_MAX x (min_TOW / max_TOW)
These values don’t have to be something exact like Autotune produces, eg: 25678.31, you can just round them off to whatever works best for you, like 20000.
And you could even reduce the ATC_ANG_RLL_P and ATC_ANG_PIT_P a little and do some test flights, checking logs.

HNOTCH phase 1
INS_LOG_BAT_MASK,1 IMU 1
INS_LOG_BAT_OPT,0 capture pre-filter gyro data

• hover test in ALTHOLD >1 minutes, check FFT

HNOTCH phase 2
INS_HNTCH_ENABLE,1
INS_HNTCH_MODE,1 throttle based
INS_HNTCH_REF,hover_thrust
INS_HNTCH_FREQ,peak freq from FFT
INS_HNTCH_BW,peak_freq / 2
INS_HNTCH_ATT,40
INS_LOG_BAT_MASK,1
INS_LOG_BAT_OPT,2 capture post-filter gyro data

• hover & dynamic test ALTHOLD >1 minutes, check FFT results

HNOTCH phase 3
INS_LOG_BAT_MASK,0
INS_LOG_BAT_OPT,0

• no extra logging, assumes HNOTCH is working great

[RoboMotic (AMV)]

@xfacta

You should be able to get all these little wiggles out of the attitude

Thank you! I will do it.
about my second question, what do you think? Why I couldn´t take off again? will be great if @philip can give us a hand too.

thanks

[RoboMotic (AMV)]

BTW, what do you mean with min/max_tow?

[xfacta (Shawn)]

min/max_tow = minimum and maximum take off weight
So if you Autotuned with absolute min take off weight of say 10kg and achieved ATC_ACCEL_P_MAX,45337.77
then you added 4kg payload = 14kg TOW
you would do 45337.77 x (10/14) = new ATC_ACCEL_P_MAX, 32,384.121428
round that down to 32000 if you like

Also try increasing ATC_INPUT_TC to 0.2 or even as high as 0.3

Try lowering the disarm delay
DISARM_DELAY,5
It’s not obvious to me why your aircraft didn’t disarm sooner, but the motors were ramping up to try and maintain stability (the best it could) then motors tried to ramp up more because of your throttle and pitch/roll inputs but it was too late.
It’s not a Cube issue, just tuning of Arducopter and all the physical components together.

[xfacta (Shawn)]

NOTE: don’t take this as advice to avoid the previous suggestions - they should all be implemented regardless of the following comments.

Actually, looking at the log again this is what I think contributed:
As you are landing the HDOP (horizontal accuracy) is rising (a bad thing) and GPS speed is going up indicating the GPS position is moving, thus causing the aircraft to try and shift while landing gear is on the ground, causing the tip over.

• Try improving your GPS reception and maybe move it higher up away from the battery.
• Try some different GNSS settings to see what works best in your region, probably:
• GPS_GNSS_MODE,65

You will need to test though. For example where I am we get really good BeiDou reception and a high number of Sats, but poor HDOP, so it’s essentially useless. For me GPS and GLONASS gives best accuracy and reception on ordinary receivers. More than 2 constellations can easily overwhelm a standard receiver too.

[RoboMotic (AMV)]

Thanks!

Aboout this, I have asked here some time ago, becase if I use the Here2 with CAN connection, the HDOP always went very high. This is the post, and in fact, is the same drone.

Here2 CAN High HDOP, Here2 Serial HDOP OK

Hi I have realize on my new drone the HDOP was very dificult to get less than 1. In fact, it never did. I though may was a bad day, but then I did some research in the forum here and I saw there were more cases of this. Today I have try again, in a place where I know is good GPS signal. In fact I try first with and old drone with BackCube and HEre2 Serial, and I got 0.9 HDOP very fast. So I have try again my new setup, OrangeCube 4.0.4, Here2 CAN, and again as the same as the first time, the…

What do you think?

[RoboMotic (AMV)]

Hi @xfacta , did you saw the link about eh HDOP and CAN? thanks!

[xfacta (Shawn)]

Yes I saw, but at this stage I dont know what to do about HDOP values using CAN connection.

[RoboMotic (AMV)]

I just connect the Here2 as serial and problem solved, no more landing issues.

[Alvin]

Can you try to connect the Here2 as CAN, then modify its node id from original value?
I don’t think the mode on Here2 would cause landing problem. It might be software problem, or maybe some data is not feeding into the ardupilot correctly.

[Agridroni (Antony)]

In another 3d I reported the interference problems in the canbus with i2c magnetometer but no one has really considered the matter. I had solved it by changing the canbus addess. In my opinion there are several critical issues of interference in the canbus

[RoboMotic (AMV)]

Hi Alvin

I cant, beacuase the drone was already delivered. I will try to do it in another drone when I have it.

I remember the landing, the drone start to drift meanwhile is was landing (the same place where we have landedn before, with open sky, no metals near), so when it touch the ground it keep drifting, didnt detect it was already on the ground and tip over. I saw did was happening and I try to take off again, but the drone didnt respond.

thanks

[Alvin]

In this case, we need log to see what happened on the drone.

[RoboMotic (AMV)]

here is the new link

LandingNotDetected.zip

Thanks!

[xfacta (Shawn)]

I just checked a Cube Black with Here3 (CAN only) and HDOP was about normal for this area (0.83 to 0.61), number of sats is normal and there’s no abnormal position drift while stationary (groundspeed between 0.04 and 0.009)

[Alvin]

Your mags, especially in Y axis, had strange patterns. They are definitely interfered by something.

However, the pattern doesn’t match motor output nor current. So I’m not sure what is the source of interference.

Looks like the system tried to pull it back, but unsuccessful.

[RoboMotic (AMV)]

Hi Shaw, the problem is with the Here2 over CAN. Here3 works fine.

[RoboMotic (AMV)]

Thanks Alvin.

I have been reading some people have reported the Li - Ion Battery could generate some electrogmagnetic issues. Im ussing the Li-Ion Diamond foxtech baterry, and in fact is installed on the right of GPS. here is a picture

what do you think?

[Alvin]

Usually the battery itself won’t cause interference but the power wires coming out from it. If wire is close to the gps module it can cause large interference.

You may try to elevate your GPS module at least 10cm from high power devices.