:
(t) = K(t)
.
, , , , , .
.
:
h(t) = L-1[W(s)/s] = L-1[K/s] = K1(t)
.
:
w(t) = L-1[W(s)] = Kδ(t)
. 3.5. , , .
.
, , :
W(jω) = K = K +0j
A(ω) = = K
φ(ω) = arctg(0/K) = 0
L(ω) = 20lg[A(ω)] = 20lg(K)
, . 0 ¥, , ω → ∞. , .
I-
.
.
I- :
W(s) = K/(Ts + 1)
K ; T , , .. . , , .. (T > 0).
.
I- :
Td(t)/dt + (t) = K(t)
.
I- : RC-; ; ..
.
I- :
h(t) = L-1[W(s)1(t)] = L-1[K/(s(Ts + 1))] = K Ke-t/T = K(1 e-t/T)
. 3.6. I- .
I- . : h = K. t = 0 t = T. t = T : h(T) ≈ 0.632K, .. T 63% .
T I- . , , Δ. ( , Δ 5 % ).
|
|
h(T) = (1 Δ)h = (1 Δ)K = K(1 e-T/T), -T/T = Δ, T/T = -ln(Δ), T = [-ln(Δ)]T.
Δ = 0,05 T = - ln(0.05)T ≈ 3T.
, I- 3 .
.
I- :
w(t) = L-1[W(s)] = L-1[K/(Ts + 1)] = (K/T)e-t/T
. 3.7. I- .
I- t = 0. - , δ-. δ- , , , , .
.
, , I- :
W(jω) = K/(Tjω + 1) = K(Tjω 1)/[(Tjω + 1)(Tjω 1)] =
= K(Tjω 1)/(-T2ω2 1) = K/(T2ω2 + 1) [KTω/(T2ω2 + 1)]j
. 3.8. , , , I- .
I- . , , - , .
: . . , , .
: T2w2 <<1; .. w<<1/T; T2w2. : L(w) = 20lgK. .
: T2w2 >>1; .. w>>1/T; 1 T2w2. L(w) = 20lgK 20lgTw. -20/. ( , 10).
ω1 = 1/T, . :
DLmax = (20lgK) [20lgK + 10lg(T2w12+1)] = -10lg2 -3 .
, I- (K T) 3 .