CAN / UAVCAN ESCs.
I know there is several topics on the CAN ESCs. I thought is best to have a fresh DEV topic on CAN ESCs and the development ‘wants’ and ability of them.
I appreciate there is much work going on with CAN dev:- https://gitter.im/ArduPilot/CANBUS
I did not want to butt in to the discussion so I am posing here.
From my perspective as a commercial UAV operator CAN ESCs are a must next step. The question is what we do with them…… rather the data they can feed back.
Some benefits are clear like potential neater wiring and auto detect motor layout ect.
The main thing is data from the ESC
Temp (external motor temp would be good)
From this we can derive motor and ESC health which from a commercial operator is paramount for safety.
Question is what to do with the data? Looking at a multirotor:-
We can detect a motor is failing,
Inform pilot via Mavlink ‘YES Please’
Can Ardupilot take evasive action, difficult one, it really depends on rig build i.e. can the rig sustain a failed motor? If so an RTL is initiated, if not then at least a LAND. My personal feeling is all commercially used rigs must be capable of at least one motor fail and sustained flight.
If Ardupilot knows there is a motor / ESC fail it can have a heads up to allow it to try and fly the rig home.
Shut motor down is a clear one, to prevent overload and fire.
What are the criteria of a fail? How do we decide a motor is failing? APMs VS expected RPM / requested rpm perhaps. This probably would require some sort of calibration i.e. motor and prop performance test during setup but this would not really reflect real flight characteristics. Can this be detected purely from expected RPM and actual RPM?
NOTE the Freelfy Alta FAIL! The ESCs were too sensitive to prop disturbance, shutting the motor down causing crashes…
LOG:- is there head room for logging 8x motor data sets? If not perhaps this could be an option if we have a PH2.1 with the Edison (or some other CC setup) and it can to the logging.
We are fortunate enough to be in the position to take on some development staff soon. I would be more than happy to assign one of the developer’s time and some funding towards developing and testing a new ESC. I note there are some issues with the ESC V1.6 but is this a baseline we can use as a start.
Ardupilot is assumed and I want to do my bit to support the development and I think this is where I can help.