Using SET_ATTITUDE_TARGET to control quadcopter

ArduCopter
1

Hi,
I want to control the quadcopter from a companion computer using SET_ATTITUDE_TARGET.
If, for example, I want to move forward\backward, I set the pitch, which causes the copter to accelerate. If I want to estimate the acceleration, I need to know the mass (Which I know, since I have a scale on my table) and the thrust. Is there anyway to get the current thrust value?
This brings me to another question - what is the meaning of the thrust value in the SET_ATTITUDE_TARGET command? I understand that 0.5 maintains the altitude, but how is the range (0.5,1] interpreted to thrust in physical units?

Thanks!

2

None of the Mavlink messages appear to give thrust information back to the user, and looking at the Arducopter source code, there is nowhere that the mavlink_msg_set_attitude_target_encode() is used, so I have to deduce that getting thrust information at present is impossible.

Did you get anywhere with this?