Hi,
I was wondering if anyone here could answer this, or at least refer me to someone who can...
The thing is, for my M.Sc. graduation project I'm trying to implement the Chinook CH-47D AFCS in a Matlab/Simulink computational environment, and currently I'm stuck on the inner workings of the first stage mixing unit.
Apparently, the AFCS pitch control laws have 2 output commands, one to the pitch SAS servo and one to the DASH (differential airspeed hold) servo. These two are accumulated with the pilot control inputs and the other control law outputs (both through the ILCAs) in the first stage mixing unit. This results in two outputs: lateral cyclic and collective pitch (something related to this has been discussed earlier in this thread I believe
). My question: what are the mixing equations? I have been able to find some data on the mixing equations of the pilot controls only (from stick input to rotor angle output), but these are unaffected by the DASH and SAS controllers, so there must be a separate set of equations for the first stage mixing.
I don't have a training manual, and I don't know who else I should contact to ask this crazy stuff
