Tuesday, March 18, 2014

Improved quadcopter - more "avionics" and increased run time

In the several weeks that followed a crash caused by an ESC failure, plenty of work have taken place (some of which documented here). Several things have been done since:
  • Replacement of the ESCs with a 30 Amp quad ESC;
  • Upgrade of the flight controller firmware;
  • Building and programming the PPM Sum encoder;
  • Building a BEC/filter with 12 V and 5 V outputs;
  • Adding landing gear;
  • Adding voltage and current sensor;
  • OSD firmware upgrade;
  • Change of LiPO battery from 11.1 V (3S) to 14.8 V (4S);

After some effort tuning the PIDs, this machine is becoming very obedient and stable, which is suitable for aerial filming.

While I haven't yet went through a full battery discharge, still I managed to attain 17-18 minutes from each battery, until I had to leave and do other things (e.g. parenting). This is a very promising figure, taking into account that the full weight of the quadcopter is currently around 1.9 Kg. I expect it to get past the 2 Kg after adding the gimbal with the Mobius camera.

Below is a video onboard the helicopter, with the current measurement working (for some reason the voltage display disappeared before this recording, to never reappear - this is not the first time it happens, and I suspect the MinimOSD extra firmware might be corrupting the EEPROM under some specific circumstances).

And here is the home-brew BEC in operation, powering the Video TX, OSD and camera:

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