APPROXIMATE LATERAL TRANSFER FUNCTIONS

In Sec. 9.7 we presented two approximate second-order systems that simulate the complete fourth-order system insofar as the characteristic modes are concerned. These same approximations can be used to get approximate transfer functions for control response.

(d) Fig. 10.11. (Cont.)

са

(е)

О) Fig. 10.11. (Cont.)

(f)

(а)

(С)

(d)

Fia. 10.12. (Cont.)

со (е)

Consider first the Dutch-roll approximation (p.374). Taking the Laplace transform gives

W„ – S)	1 M i-1 ________ 1	P	__	1 О I________		———– 1
	{jrr – s)_	f				A-

(10.5,5)

^a = ~f + bA

l-z

The four transfer functions for j3 and r responses are readily found from

(10.5,5) to be