Quadcopter flip forward by it self , ver 1.8/1.9

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adam
Posts: 15
Joined: Sun Oct 02, 2011 4:26 pm
Location: Taiwan

Quadcopter flip forward by it self , ver 1.8/1.9

Post by adam »

Hi there,

I am pretty like at flying now with my Quadcopter-x + WMP clone only and default PID ver 1.9!

http://youtu.be/cptQiEtS6LQ
http://youtu.be/MwJ4JdjYkqM

But only one thing, let me confusing of it - flip forward by itself !
Some time In the air smooth flying, Some time under ground ready to take off .
Suddenly the motor 11 and 9 get full power, then flip forward !

I am very confusing of it !

Thank you

Adam

TextZombie
Posts: 24
Joined: Mon Nov 14, 2011 2:05 pm
Location: Sheffield, UK
Contact:

Re: Quadcopter flip forward by it self , ver 1.8/1.9

Post by TextZombie »

I've had this on my hex and finally worked out in my case it was down to the bluetooth module I had plugged into the serial port on my pro mini. With the copter on the ground and the props off I'd wiggle the bluetooth module and get the back two props on full power for a few seconds, then the pro mini would seem to crash, and all the ESC's would start beeping the motors. This behaviour had caused me 5 or 6 severe crashes in the past.

I haven't yet managed to fully get to the bottom of it, but I suspect spurious signals into the serial port of the arduino cause the problem. I can't tell from your video how your boards are set up, but you could try isolating your serial port with a dummy connector or even electrical tape (both on the connector and under the arduino) to make sure nothing is shorting out on the serial port, and if you're flying with anything plugged into the serial port, unplug it.

P

adam
Posts: 15
Joined: Sun Oct 02, 2011 4:26 pm
Location: Taiwan

Re: Quadcopter flip forward by it self , ver 1.8/1.9

Post by adam »

TextZombie wrote:I've had this on my hex and finally worked out in my case it was down to the bluetooth module I had plugged into the serial port on my pro mini. With the copter on the ground and the props off I'd wiggle the bluetooth module and get the back two props on full power for a few seconds, then the pro mini would seem to crash, and all the ESC's would start beeping the motors. This behaviour had caused me 5 or 6 severe crashes in the past.

I haven't yet managed to fully get to the bottom of it, but I suspect spurious signals into the serial port of the arduino cause the problem. I can't tell from your video how your boards are set up, but you could try isolating your serial port with a dummy connector or even electrical tape (both on the connector and under the arduino) to make sure nothing is shorting out on the serial port, and if you're flying with anything plugged into the serial port, unplug it.

P


In the first time same with your case, I connected the bluetooth adapter into the serial port on pro_mini. It's flip forward in the air and upside down under ground. Recently, twice, Ready to take off, throttle up to 1/3 position, it's happen. (no anything plugged into the serial port)

I will try isolating the serial port with a dummy connector and electrical tape under the PCB.

Thanks,

TextZombie
Posts: 24
Joined: Mon Nov 14, 2011 2:05 pm
Location: Sheffield, UK
Contact:

Re: Quadcopter flip forward by it self , ver 1.8/1.9

Post by TextZombie »

For me the bluetooth adapter issue is easily repeatable, I videoed it here for anyone interested:

http://www.youtube.com/watch?v=FWz44Ipg_cQ

The first time I plug the BT in while it's running it kills the Arduino and needs a reset, then the next time you hear the back two motors go full throttle for a couple of seconds before all motors die and the Arduino crashes with the green LED flashing quickly. The reset button on the Arduino doesn't function and it takes disconnecting and reconnecting the lipo to get it all going again.

It would be interesting to try and track down exactly whats happening here.

Needless to say I'm back to wired serial for PID adjustments :)

Splashy
Posts: 11
Joined: Wed Sep 21, 2011 8:26 pm

Re: Quadcopter flip forward by it self , ver 1.8/1.9

Post by Splashy »

I think I might have the same issue. When I start up my quad two of the motors start up and the other 2 remain stopped. The way to overcome this is by applying quite a bit of throttle and get the quad off the ground. Once the quad is in the air then there does not seem to be a problem. I can't say 100% that this is 1.9 related but I certainly think so. I have calibrated everything and still have this problem.

mr.rc-cam
Posts: 457
Joined: Wed Jul 27, 2011 11:36 pm

Re: Quadcopter flip forward by it self , ver 1.8/1.9

Post by mr.rc-cam »

The reset button on the Arduino doesn't function and it takes disconnecting and reconnecting the lipo to get it all going again.

That is a useful clue. The next time this happens, do not reset the Arduino. While the ESC's are beeping and the MWC remains messed up, measure the voltage on Arduino's D12 pin. If it is substantially less than 5.0V, and your BlueTooth uses the Vcc output provided by the Pro Mini, then it has probably caused the little bitty 5V VReg inside the Arduino Pro Mini board to go into voltage fold-back (over current protection).
- Thomas

oterpoter
Posts: 61
Joined: Sat Nov 05, 2011 2:11 am

Re: Quadcopter flip forward by it self , ver 1.8/1.9

Post by oterpoter »

I am encountering almost the same thing, only that mine is rotating sideways (to the left). And it seems that it gets a feedback-loop because it acellerates the rotation. I cannot prevent a crash when this happens, and the last 2 flights it happened after some minutes of flying..
Because of this I am reluctant to go flying before I know the cause of this, and hopefully also the solution.
I am starting to suspect that the stable mode gets all screwed and that it starts to invert the stability, only making it go into a deadly spin.
Either way, this is annoying!
I bought the Flight Controller from quadframe.com. Hopefully Jakub will give me some answer/hint to what can be the problem..
I have nothing connected to this quad apart from ESC/Motors and LEDs maybe the LEDs should get their power from a standalone battery? This again will add some extra weight..
I am in the middle of building a octocopter from scratch, with OSD and VideoDownlink, and the videocamer/OSD will have its own power source, and i sm guessing that the LEDs should be powered from that same battery.
A note: the blue LED strip from HobbyKing does not illuminate bright blue, but looks as if it gets too little currency, but the RED strip is fine.. Maybe there is a power consumtption issue???

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