flight controller

[wengwah]

Just curious, why are you giving up this Hobby.

Is it because of the technical problem in getting it to fly?

Hi,

Came upon this thread.....
If you are keen.....I do have a Arduflyer from rctimer...am thinking of letting go.
PM me if anyone is interested.

OT: pls pardon me.

Arduflyer board is brand new comes with CN-06 GPS Ublox. Only flown once to test. Still new, if offer is good.....I'll throw in the Mega case.

Thanks.

[newfly]

[QUOTE=wengwah;591655]Just curious, why are you giving up this Hobby.



Is it because of the technical problem in getting it to fly?


I'm letting go my board if offer is right. I'm not giving up hobby....
I hope I clear your understandings.

[shoyn]

Bought the arduflyer from rctimer. Now waiting for it to arrive at my door step along with my order from hobbyking. What is left will be the motors.

[perdification]

Hey buddies, I'm tuning my Megapirate and am getting the toilet bowl effect some times when I give stick inputs similar to that manner. As in, when I do a circle motion on my right stick (mode 2), the copter will follow the movement and even when I keep the right stick centered, it is as if the motion perpetuates and gives me the toilet bowl effect. But if I disrupt the motion, it will hold steady. Is it my P gains not being high enough? I am flying in acro mode, since I'm still trying to tune it properly in acro first before going to stabilise mode.

Another observation is, after 1 battery pack of tuning, when I strap on the second pack and start tuning in stabilise mode, the copter will lift off normally, then it will suddenly jerk/jump randomly and then stabilise again. This happens more than once throughout the flight. So I thought it was something wrong with stabilise mode and I switched back to acro mode, only to find that the same thing happens. Could it be that the vibration is reaching the FC? I didn't experience this problem for the first battery though...

Any help would be greatly appreciated!

[perdification]

I hope I have described the problem properly... I think it's called twitching... which is very similar to this:

Although mine is not as serious as this, it is still there, and very annoying. I've already calibrated all my ESCs one by one manually. Motors are working, tested on another quad with no twitching.

[perdification]

Okay bros, I observed that twitching happens mostly on the roll axis, and a little on the pitch axis, none observable on the yaw axis.

My initial PID values when I got the twitching:

Roll:
P: 0.035
I: 0.45
D: 0.007

Pitch:
P: 0.05
I: 0.5
D: 0.0075

Yaw:
P: 0.2
I: 0.45
D: 0.0035

Now, after some tweaking, the situation improves quite a bit... But occasional (Less frequent) and less obvious twitching still exists, here are the changes I have made.

Roll:
P: 0.0600
I: 0.1000
D: 0.0030

Pitch:
P: 0.0500
I: 0.0500
D: 0.0060

Yaw:
P: 0.0700
I: 0.4500
D: 0.0035

I have changed quite a lot of values based on changes I have observed, but I don't understand why it diminished. I'd appreciate if anyone can guide me to eliminate all the twitches.

[wengwah]

Hi, keep yaw to default.

Keep P, I and D low.

Increase P gradually, next increase D. Lastly increase I.

My experience is on MultiWii and the number looks different. My order for another AIOP is coming in this few days and will be setting it up soon with SimonK ESCs.

You should be getting a very stable configuration.

This should be the type of stability with SimonK ESC.

[wengwah]

This is AIOP on a HexCopter with Megapirate. This chap is selling at £345

[perdification]

Thanks a lot my friend. I will try the steps you listed. I was previously following this guide: http://diydrones.com/profiles/blogs/...ng-howto-video

I will report back to you my findings... I have read somewhere that twitches might be caused by incompetent bullet connectors from the ESCs to motors... could it be the case? In any case, I will try to resolder the bullet connectors... I'm doubting the integrity of my whole setup now, because it's DIY. But the beauty of DIY is this: my whole AUW is only 650 grams with a 3S 2200mah Lipo flying with a 10x4.5 prop. I've designed the frame to be able to support 12x4.5 props, I just need to change out the motors...

[perdification]

Okay wait I am getting a little confused. I have been changing the Rate_P, I and D, but I set the Stabilise_P, I and D to zero while tuning my rate. I thought stabilise PIDs only come into play when in stabilise mode and not acro mode? I read somewhere that seems to suggest that stabilise PID values have an effect even when in pure acro mode.

[nubie.pilot]

Okay wait I am getting a little confused. I have been changing the Rate_P, I and D, but I set the Stabilise_P, I and D to zero while tuning my rate. I thought stabilise PIDs only come into play when in stabilise mode and not acro mode? I read somewhere that seems to suggest that stabilise PID values have an effect even when in pure acro mode.

Is there any power lines underneath your FC or do you put your lipo underneath your FC? If yes, try put the FC higher so it has more distance from the powerline, or if you can, twist the power cable underneath the FC.

The powerline generates magnetic field and it giving lots of noise for the compass, this is the reason why DJI puts the compass and GPS using stand off support.

[perdification]

Is there any power lines underneath your FC or do you put your lipo underneath your FC? If yes, try put the FC higher so it has more distance from the powerline, or if you can, twist the power cable underneath the FC.

The powerline generates magnetic field and it giving lots of noise for the compass, this is the reason why DJI puts the compass and GPS using stand off support.

Thanks for your reply. So you suspect that twitching is due to EMI caused by the powerlines?

I have attached a few photos of how my FC is mounted and it's relations. There's a space directly below my FC with nothing there. Yep, below the white foam board, the lipo is mounted there. Is it a far away distance? During flight, the power wires from the lipo are hanging in mid air, and pretty far away from the FC. But you can see that many wires are going to my FC, which is inevitable since it has to make connections...

My GPS is on a DIY wire stand, high up and away from everything else. I previously made the stupid mistake of mounting the GPS directly on top of the FC, and found that it couldn't even get a fix. Now it gets a 3D fix almost instantaneously after I power it up. Too bad the compass is on the FC and I can't take it out.

My ESCs are a fair distance away, closer to the motors than the FC.

I'll find time soon to resolder the motor bullet connectors and tune the PIDs again... But as to the Lipo mounting, I have no idea where to mount them...

[perdification]

Okay, looking at my own photos, the distance from the lipo to the FC is about 2.5 cm away, and is separated by a thin sheet of fibreglass, wood, styrofoam, and air in between. However, I realised that the ferrite rings are directly on the FC. Could it be the ferrite rings that are going to the ESC??? Dang! It slipped my mind until now!

[wengwah]

I had tested this before and I am quite sure that your setting is incorrect. It is not due to EMI.

I had my GPS sitting next to my FC and it is very stable.

[wengwah]

Hi, any chance to snap of the complete build and share with us your configuration. My parts have arrived and I am about to build one using Megapirate on a Locust frame.