Expert Opinion on my Quadcopter Tuning

ArduCopter Copter 4.0
1

I want comments and opinion of expert members of this forum on my Quadcopter Tuning.
Frame: Quad 1300mm Arm to Arm
Prop: 29x9.5 CF T motors
Motors: U8Pro KV170 T motors
ESC: Air40A T motors
MTOW: 7.6kg

I followed the procedures listed on wiki section for basic setup and tuning . Even configured the harmonic notch filter and performed manual tuning.

Pl comment on how do you rate the tuning of this aircraft. My observation was it flew very well on windless conditions but on high winds performance was not good. What you suggest for better performance in high winds?

Im attaching my log file with the post. This log was obtained on clear day with no wind.
https://drive.google.com/file/d/1iVUo_w048kqNuSZ1hyKbbDQKKf6HjUXS/view?usp=sharing

Im also attaching few graph images of log file desired roll/pitch vs actual roll/pitch and desired roll rate/pitch rate vs actual roll/pitch rate.

Roll
Roll1022×473 9.67 KB

Pitch
Pitch1011×456 10.7 KB

Roll Rate
Roll Rate1186×651 14.7 KB

Pitch Rate
Pitch Rate1162×631 13.8 KB

2

@andyp1per
@dkemxr
@xfacta
@hosein_gh

Your valuable comments required please
Thanks in advance!

3

hi @Aorish_Imtiaz
looking at ATT values it shows that you still have noise problem even with configured harmonic notch filtering
also you can see oscillation when copter tries to stabilize it self after movement

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Screenshot_2
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looking at RATE values we can see this noise better

Screenshot_5
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and there is motor unbalance in log, but its not because of bad physically balance
CCW motors are working harder and i was faced this problem with high noise on accelerometer

Screenshot_3
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by looking at IMU values we can see this noise

Screenshot_4
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by harmonic notch filtering you have been defused gyro noise

Screenshot_6
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but noise on accel is a little bit high

totally i think main problem is high noise on ACC values and its affecting EKF measurement then oscillating and poor performance in wind

please send some pictures of your frame and how motors and FC mounted on frame

i think this part could help to solve this problem

1 Like
4

Thanks for your insight!
So you think my Stabilize and Rate Gains are configured fine? Should I put more effort in tuning or not?

I ll send you pics of the frame and motor mounting tomorrow!

5

its hard to say before solving noise problem but its seems that they are good but not grate

6

My flight controller is Cube Black with standard carrier board and it is hard mounted on airframe directly with double sided tape!

7

Current monitoring is not working correctly, it will be useful to fix that.
There is that motor alignment to sort out too…
There are some other slightly odd parameters there and I would probably change:
ATC_THR_MIX_MAN,0.5
ATC_RAT_PIT_FLTD,8.5
ATC_RAT_PIT_FLTT,8.5
ATC_RAT_RLL_FLTD,8.5
ATC_RAT_RLL_FLTT,8.5
ATC_RAT_YAW_FLTT,8.5
INS_ACCEL_FILTER,17
INS_GYRO_FILTER,17
MOT_THST_EXPO,0.8
PSC_ACCZ_I,0.4852
PSC_ACCZ_P,0.2426
BATT_FS_LOW_ACT,2
BATT_FS_CRT_ACT,1

Also how did you come up with ATC_THR_MIX_MAX,1.5 ?
It would normally be 0.5 too. I’m curious about that one.

PIDs look a little odd to me, but that could just me. Did you derive them manually or by Autotune?
I would have expected something closer to this:
ATC_RAT_PIT_P,0.15
ATC_RAT_PIT_I,0.15
ATC_RAT_PIT_D,0.005
ATC_RAT_RLL_P,0.15
ATC_RAT_RLL_I,0.15
ATC_RAT_RLL_D,0.005
But I am genuinely curious and not saying yours are wrong. Every craft will be different, and yours has a rather big wheelbase for a Quad and big motors and props. If you were to change any of those things, be especially cautious of the PIDs since your craft is actually flying.

Probably do more autotunes…

Wind might always be a problem with props that size too.

1 Like
8

@hosein_gh
Here are pictures of my airframe and motor mounting. Flight Controller is directly mounted with double tape on airframe

received_2800982473470168
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9

Thanks for your suggestions. I will incorporate them and then fly and post the log

Regarding current sensor Im incorporating mauch sensor and soon it will be working.

Can you explain motor alignment case in detail?

Regarding ATC_THR_MIX_MAX I read somewhere it help keeps big copters attitude in control while descending so I increased its value!

PIDs were derived manually! On lesser winds the copter flies very good. By looking at the log file how do you rate my tuning effort? What should be done to have better wind resistance?

10

@gnitzan your opinion is also needed please!

1 Like
11

everything looks good try jello killer it was helped me on large drones
also you can use soft silicon layer under you motors to defuse vibration

1 Like
12

Will putting silicone under the motors cause any misalignment? This is my concern!

13

Yes it cloud cause and you should chek and fix motors level after adding silicone

14

If you actually read the notch filter documentation you will discover the notch does nothing to the ACC noise. The notch cleans up the gyro signals which drive the PID controllers…

15

@Aorish_Imtiaz : What EXACTLY does the aircraft do in windy conditions?

16

i know men as i noted

17

So why did you tell the OP to soft mount the motors which will throw the motors out of alignment and cause more problems?

1 Like
18

i think you did not read whole thread
first i suggested these motor dampers that i used them without any problem

then i suggested silicon under motors that could solve problem but aligning motors are a little bit hard but not impossible !
i used soft silicon on s550 and daya 550 frames and result was perfect
other users also tried this with success
but foe mine it was took 4hrs to completely align motors by screws