LibrePilot Forum

Users => Vehicles - MultiRotors => Topic started by: sallyc on November 09, 2017, 06:17:48 pm

Title: quadcopter flying problem
Post by: sallyc on November 09, 2017, 06:17:48 pm
Hello,
I have a reely racecopter x250, I am using the next branch librepilot GCS and firmware. But it is always crashed before taking off, I have ruined 4 pairs of propellers already.

Few months ago I configured it with 16.09 version and everything is fine, could it be the firmware problem?

Well, the only thing that I didn't configure is that in the flight data, I can see that pitch and yaw are in reverse, that means, when i grab the copter in my hand and pitch it down, in the GCS flight data panel,  it looks like yaw right.  I this I can change this in the attitude tab to rotate it, but does this influence the flying? I failed taking off because of this or version or something else maybe?
Title: Re: quadcopter flying problem
Post by: TheOtherCliff on November 09, 2017, 06:51:21 pm
When watching the display, the pitching should look normal.  You seem more brown ground when you pitch it forward.  The roll should look backwards.  When you roll it left the display should go right.
Title: Re: quadcopter flying problem
Post by: TheOtherCliff on November 09, 2017, 06:56:59 pm
Other than that there are may things that can make it flip on takeoff:

Stabilization -> Bank# -> ZeroTheIntegral should be ENABLED
ESCs plugged in FC in the correct order (1=NW, 2=NE, 3=SE, 4=SW)
Arrows on board should be point forward or proper rotation configured in Attitude -> Settings -> RotateVirtual (do you have 0,0,0 for RotateVirtual and arrows on FC point forward, ESC connections on right side?)
Motors spinning in the correct direction (see vehicle tab for a picture)
Need correct prop types on correct motors (visually/physically verify that all motors blow downward)
Take off from level ground
Take off quickly as soon as you start motors
Jump it up to knee high, do not take off slowly
Leave transmitter sticks in the middle until it is in the air, don't touch!
Wrong PIDs, try default PIDs

If everything is correct, then Flight Data page PFD (top left) when making motions with quad in hand will look correct for pitch (forward banking/rotation shows more brown dirt) but will look backwards for roll (bank/rotate quad left will make screen go right).  Model View (bottom left) will look correct in all regards, but it can confuse you if the virtual model is rotated to point toward you.
Title: Re: quadcopter flying problem
Post by: sallyc on November 09, 2017, 08:41:23 pm
Other than that there are may things that can make it flip on takeoff:

Stabilization -> Bank# -> ZeroTheIntegral should be ENABLED
ESCs plugged in FC in the correct order
Arrows on board should be point forward or proper rotation configured in Attitude -> Settings -> RotateVirtual
Motors spinning in the correct direction (see vehicle tab for a picture)
Need correct prop types on correct motors
Take off from level ground
Take off quickly as soon as you start motors
Jump it up to knee high, do not take off slowly
Leave transmitter sticks in the middle until it is in the air, don't touch!
Wrong PIDs, try default PIDs
thank you, i will try it and let you know the result/
Title: Re: quadcopter flying problem
Post by: memz180 on November 15, 2017, 04:32:01 am
When watching the display, the pitching should look normal.  You seem more brown ground when you pitch it forward.  The roll should look backwards.  When you roll it left the display should go right.

Hi Cliff, When roll left or right the display data is indicating the same movements as the quad-copter is this a problem ?

Thanks.
Title: Re: quadcopter flying problem
Post by: TheOtherCliff on November 15, 2017, 05:29:57 am
When you watch the "F16 display" / PFD / HUD on the Flight Data page you see an artificial horizon.  When you roll the aircraft left, the "world in the display" should tilt right.  If not, you have board not mounted "upright with arrow forward" or "Attitude -> rotate virtual is wrong"
Title: Re: quadcopter flying problem
Post by: memz180 on November 15, 2017, 07:29:00 am
My one is like the one in the below. which is incorrect ?

https://librepilot.atlassian.net/wiki/spaces/LPDOC/pages/5669067/PFD

Also as per the little graphics of the quad the movements are exactly as per my movements in real life, which i would assume its setup correctly ?

Title: Re: quadcopter flying problem
Post by: TheOtherCliff on November 15, 2017, 08:54:26 am
Picture at the bottom.  Board tilted right, ground tilted left.  That is correct.

You said "When roll left or right the display data is indicating the same movements".  That sounds like when you tilt the board left the ground goes left.  That is wrong.
Title: Re: quadcopter flying problem
Post by: memz180 on November 15, 2017, 11:27:35 am
I think i finally got it. If the quad is facing you front side and you roll left and right it should be the same movements as the flight data.

If i turn the quad around and face the back its opposite as per your post above. Hopefully this is correct.
Title: Re: quadcopter flying problem
Post by: sallyc on November 17, 2017, 02:03:37 pm
Other than that there are may things that can make it flip on takeoff:

Stabilization -> Bank# -> ZeroTheIntegral should be ENABLED
ESCs plugged in FC in the correct order
Arrows on board should be point forward or proper rotation configured in Attitude -> Settings -> RotateVirtual
Motors spinning in the correct direction (see vehicle tab for a picture)
Need correct prop types on correct motors
Take off from level ground
Take off quickly as soon as you start motors
Jump it up to knee high, do not take off slowly
Leave transmitter sticks in the middle until it is in the air, don't touch!
Wrong PIDs, try default PIDs
Hello, Cliff, I checked everything you mentioned, when I grab it in my hand and try to feel it flying, it didn't feel so stable and feels like crashing, in oder to not ruin it again, do you know is there a configuration to decrease the speed of the quadcopter? because i have a racecopter and the accelarate speed is too quick.
Title: Re: quadcopter flying problem
Post by: sallyc on November 17, 2017, 05:08:13 pm
and I tried, still failed to take off, i am thinking if it is the problem of transmitter because when I keep the throttle stick stable, it is sometimes accelarate itself and sometimes not. And sometimes when I try to arm it it is not working.
Title: Re: quadcopter flying problem
Post by: TheOtherCliff on November 18, 2017, 03:43:10 am
Have you calibrated ESCs and set motor neutrals?
https://librepilot.atlassian.net/wiki/spaces/LPDOC/pages/12058743/ESC+Calibration

Another possible problem is bad PIDs.  Have you tried stock PIDs?  Have you tried AutoTune?
https://librepilot.atlassian.net/wiki/spaces/LPDOC/pages/25657377/AutoTune

Even with racer you should be able to control takeoff and flight, not much more difficult than a less racy copter.  The fact that you are having problems sounds like something besides "too powerful".

When you try to hold it in your hand is it trying to lift too strongly or is it trying to twist out of your hand?

After ESC calibration and neutral setting if you still have problems, if you could make a video of trying to take off we might see something to discuss.
Title: Re: quadcopter flying problem
Post by: sallyc on November 18, 2017, 12:28:01 pm
when I tried to hold it in my hands, I can feel that it is trying to crash.
And my copter is cc3d so i don't have autotune.
I was successfully configured it before, now I did the same but not work.
When I held the throttle stick still, i can hear that the copter is speeding up but it should have stayed in where it kept the throttle stick.
Title: Re: quadcopter flying problem
Post by: TheOtherCliff on November 19, 2017, 12:41:03 am
Motors speeding up is normal.  That is PID "I" term windup.  It does not happen in flight.

Rate mode is safest for this test:  If a simple test of holding the quad in your hand and starting the motors to a very slow setting makes it try to violently twist out of your hand, then it is a setup problem.  It is best to do this test wearing a winter coat and gloves to protect your hand and arm.

Two wrongs do NOT make a right.  E.g. wrong motor direction cannot be fixed by using wrong prop.

Check everything:
motor directions
correct props on those motors
Flight data page PFD is stable and works correctly (roll left makes it go right, and nose down shows brown dirt)
ESCs plugged into FC in correct order
Vehicle page motor output channels are set to the correct order (usually NW, NE, SE, SW is 1,2,3,4)
FC mounted upright with arrow pointing forward or carefully researched RotateVirtual settings have been made
Stabilization ZeroTheIntegral is ENABLED
watch sticks on HITL page to make sure they follow what your sticks do (nothing backwards)
take off quickly after you start the motors
take off from a level surface
Title: Re: quadcopter flying problem
Post by: sallyc on November 21, 2017, 05:36:07 pm
Motors speeding up is normal.  That is PID "I" term windup.  It does not happen in flight.

Rate mode is safest for this test:  If a simple test of holding the quad in your hand and starting the motors to a very slow setting makes it try to violently twist out of your hand, then it is a setup problem.  It is best to do this test wearing a winter coat and gloves to protect your hand and arm.

Two wrongs do NOT make a right.  E.g. wrong motor direction cannot be fixed by using wrong prop.

Check everything:
motor directions
correct props on those motors
Flight data page PFD is stable and works correctly (roll left makes it go right, and nose down shows brown dirt)
ESCs plugged into FC in correct order
Vehicle page motor output channels are set to the correct order (usually NW, NE, SE, SW is 1,2,3,4)
FC mounted upright with arrow pointing forward or carefully researched RotateVirtual settings have been made
Stabilization ZeroTheIntegral is ENABLED
watch sticks on HITL page to make sure they follow what your sticks do (nothing backwards)
take off quickly after you start the motors
take off from a level surface
Hello,
I checked everything you mentioned, and still failed, I will provide my uav settings, the video that i was successfully configured with setup wizard, and the video that shows the failures now. I really don't know what is wrong because both I do the same configuration. the propellers shows how I install the propellers, and white ones are in the front. the direction of motors are the same as it shows in the vehicle pages. By the way i have two of those race copters and I tried both, both are the same problem so I guess it is not hardware problem
Title: Re: quadcopter flying problem
Post by: memz180 on November 22, 2017, 11:47:39 am
This problem was occuring with me.

2 things I did to fix it.
1. Checked all motors that are exactly the same as shown on Librepilot with their order. 
2. Check your flight data to ensure that quad is moving the way your moving it. If you roll left ensure that the quad in the graphics is also. If not you'll have he instant roll.

I've been flying mine for a while now absolutely love it at the moment.
Title: Re: quadcopter flying problem
Post by: TheOtherCliff on November 22, 2017, 06:04:59 pm
It really really looks from video that stabilization is backwards / incorrect.

It starts a little unlevel say leaning left, so it tries to make it go right, but because it is backwards it goes farther left, so it tries even harder to go right which ... in human time it instantly flips.

Reading back, I see your first post you say
Quote
I can see that pitch and yaw are in reverse, that means, when i grab the copter in my hand and pitch it down, in the GCS flight data panel,  it looks like yaw right.
If it still does this than that is your problem, which says that either FC is not mounted normally or at least that RotateVirtual does not correctly match the way the FC is mounted.  This will definitely cause this instant flip.

Wiki has info about how to adjust RotateVirtual for different FC orientations.  If FC is mounted normally, RotateVirtual should be 0,0,0

I added some detail and suggest that you re-read my post about the things that cause flipping.
https://forum.librepilot.org/index.php?topic=3994.msg26880#msg26880

Good luck.
Title: Re: quadcopter flying problem
Post by: TheOtherCliff on November 22, 2017, 06:49:41 pm
I checked your prop picture and they look correct.  It still could be motor rotation wrong.  All motors should blow downward when spinning.  :)

It looks like you have the board mounted with 90 degree clockwise rotation and that you have that correctly configured in your settings (0,0,-90).

You have ZeroTheIntegral enabled as it should be.

There are things I cannot check that you will have to recheck.  First one that comes to mind is that ESCs are plugged in the correct location.  You can take props off, Output page -> Test Outputs to make sure of rotation direction and that ESCs are plugged in the correct place.
Title: Re: quadcopter flying problem
Post by: sallyc on November 22, 2017, 07:02:11 pm
This problem was occuring with me.

2 things I did to fix it.
1. Checked all motors that are exactly the same as shown on Librepilot with their order. 
2. Check your flight data to ensure that quad is moving the way your moving it. If you roll left ensure that the quad in the graphics is also. If not you'll have he instant roll.

I've been flying mine for a while now absolutely love it at the moment.
I checked this two but still failed
Title: Re: quadcopter flying problem
Post by: AerialPerPlexity on November 24, 2017, 09:03:48 am
How about the transmitter is any channels reversed? maybe pitch or roll reversed?
Title: Re: quadcopter flying problem
Post by: JardCrocker on November 24, 2017, 04:36:26 pm
Hi...i am a new user here. As per my knowledge if a simple test of holding the quad in your hand and starting the motors to a very slow setting makes it try to violently twist out of your hand, then it is a setup problem.

pcb assembly (https://www.youtube.com/watch?v=-7AI18ugw1I)
Title: Re: quadcopter flying problem
Post by: sallyc on December 01, 2017, 06:57:03 pm
thank you everyone, problem solved, it is the motor channel reversed.
i have another question, when i connect cc3d to pi and read the telemetry data from controller, why the attitude state has value even my controller is still?
Title: Re: quadcopter flying problem
Post by: sallyc on December 01, 2017, 08:08:54 pm
I checked your prop picture and they look correct.  It still could be motor rotation wrong.  All motors should blow downward when spinning.  :)

It looks like you have the board mounted with 90 degree clockwise rotation and that you have that correctly configured in your settings (0,0,-90).

You have ZeroTheIntegral enabled as it should be.

There are things I cannot check that you will have to recheck.  First one that comes to mind is that ESCs are plugged in the correct location.  You can take props off, Output page -> Test Outputs to make sure of rotation direction and that ESCs are plugged in the correct place.
And by the way, if I want to know the velocity of X, Y, Z direction, which uav object should I read?
Title: Re: quadcopter flying problem
Post by: f5soh on December 01, 2017, 09:10:27 pm
VelocityState ?
Title: Re: quadcopter flying problem
Post by: TheOtherCliff on December 02, 2017, 04:23:41 am
why the attitude state has value even my controller is still?

I don't understand.  Are you saying that Attitude State is changing even when controller is still?  How much does it change, some small amount is normal.  Maybe a picture of a Attitude State scope so we can see.
Title: Re: quadcopter flying problem
Post by: sallyc on December 02, 2017, 02:11:19 pm
VelocityState ?
VelocityState shows the velocity related to homelocation, so should I set homelacation first? And is that possible that when velocity in Z direction is zero, the velocity in X and Y are still existing?
Title: Re: quadcopter flying problem
Post by: sallyc on December 02, 2017, 02:11:53 pm
why the attitude state has value even my controller is still?

I don't understand.  Are you saying that Attitude State is changing even when controller is still?  How much does it change, some small amount is normal.  Maybe a picture of a Attitude State scope so we can see.
Title: Re: quadcopter flying problem
Post by: f5soh on December 02, 2017, 02:27:57 pm
Quote
VelocityState shows the velocity related to homelocation, so should I set homelacation first? And is that possible that when velocity in Z direction is zero, the velocity in X and Y are still existing?

VelocityState is NED :
- North and East velocity comes from GPS.
- Down velocity comes from Baro + Accelerometer correction

Assuming you are using a Revo/Sparky2 board, not a CC3D where VelocityState is not computed at all.
Title: Re: quadcopter flying problem
Post by: TheOtherCliff on December 02, 2017, 07:24:00 pm
Those attitudestate changes are down in the 1/1000th of a degree range and come from normal sensor noise.  It sounds like you need to ignore changes below some threshold.  Be careful to not just say I will look at changes in the 1/100ths place because a 0.0000001 change can change 0.1299999 to 0.1300000