Originally Posted by roulishollandais
it means that kinetic speed information comes from inertial data after integration '?
No, speed information does not appear in the C-star law as such. Airspeed affects the response of the airplane (in terms of pitch rate and normal acceleration) to changes of elevator and THS positions, and therefore may enter in the 'gains' used to calculate elevator and THS commands:
Originally Posted by Favre (1994)
A homogeneous law, ensuring aircraft behaviour independent of the flight conditions and, in particular, independent of the centre of gravity location, is achieved by tabulating the gains as a function of the computed air speed, high-lift configuration and centre of gravity location.
If you are referring to my post #1310, I didn't use airspeed either, just vertical speed and integrated SS angle to calculate pitch from:
Pitch = Pitch(0) + Ks/Kq * ∫ Sdt - Kn/Kq*(Vz - Vz(0))/g,
where S=side stick angle, Vz is vertical speed, and Pitch(0) and Vz(0) are the initial values of pitch and vertical speed.
P.S. About the cross-over velocity Vco.
The 'steady state' relationship between nz and q:
qSS = nz*g/V (4) may be written as:
Kn*nz = V/Vco * (Kq*q) and shown as:
Originally Posted by Cranfield report 9303
Section8.3: The cross-over velocity defines the ratio of pitch rate and normal acceleration feedback gains. (...) it had been argued that the cross-over velocity chosen had no apparent relation with the existing flying qualities specification (...) and so is open to question. By relaxing the definition of the cross-over velocity it becomes possible to specify feedback gains independently ...
Based on the data posted in #1310, the A330 control law uses a cross-over velocity of ...(EDIT).