Cockpit crash


#1

Hi all,

Here we are! The ROV is finished... At least the building phase.

It's almost waterproof... Enough to test it in the swimming pool!

I have a fresh updated software ( both the cockpit and the arduino code).

After starting the motors for a few seconds, the rov stops. The software seems to crash. (no more response by web nor ssh). It works fine in the air, but not underwater...

BTW, I have a weird behaviour: in the air, when I light on the leds, the video stops working. I have to restart the process to get it back.

All this makes me feel like I have a power supply issue... Just an idea...

But I can't troubleshoot it.

Please help...

Regards,

Benoit


#2

What type of batteries are you using & what is the Voltage & current capacity?


#3

Hi,

I am using the suggested trusfire batteries. They are all correctly loaded around 3.9V.

I have tested with the diagnostic panel. I can run the motors one by one, even the 3 together at a low level, but as soon as I push the motors higher, it crashes again...

I suspect a leak in the motors. How can I detect a waterproof issue in the motors?

I am lacking ideas to troubleshoot... Please help!

Regards,

Benoit


#4

Hi Benoit,

I would agree with you that it is a power supply issue.

I think the trustfire batteries struggle to supply the required current to the motors. Take a read here and you will find that the max continuous current draw for those batteries are 10A. (peak 20A)

There have been a few power consumption measurements on the forums and people have found that with the 3 motors, the current can be well in excess of 10A and running the motors in the water loads the motors even more (more current) due to the resistance from the propeller.

My suggestions-

- Have a look at this blog post- You may need to choose more efficient propellers. You could test this by removing the props and seeing if this fixes the issue when running in the water.

- Try reprogramming your ESCs to use a setting that limits the acceleration of the motors (reduces peak currents)

- Adjust the dead band settings in the ROV cockpit to be as narrow as possible so the motors only just run on the lowest speed setting

- Adjust the motor response aggressiveness in the cockpit settings (im not sure what this does exactly, but i assume it limits the motor acceleration)

also, here is another interesting link about the trustfire batteries. http://lygte-info.dk/review/batteries2012/TrustFire%20TF26650%205000mAh%20(Flame)%20UK.html


#5

Kurt,

Thanks for your reply, I now have something to try!

Regards,

Benoit


#6

Hi all,

Just to keep you posted:

- The led issue: I have noticed that the led power line and the cam cable were twisted... Since I separated them, the bug disappeared... It sounds like when powering on, the led cable was disturbing the cam signal...

- The motors issue: one of the ESC had been misconfigured... The start mode was set on level 5... Far too high.

It's now working fine!

Thanks a lot for your tips that helped me fixing it.

Kind regards,

Benoit