ϳ . , ᒺ:
(1.1)
y = y(t), - .
ᒺ (1.1). : y(t0) = y0; y(t) = yk, y0, yk .
.
( ) (. 1.1).
(1.1) :
(1.2)
, , .
ᒺ (1.1) . - ( ):
(1.3)
, (1.2) (1.3) , y(t) .
ֳ . , , . ³ , :
, (1.1) (), , :
y(t), y(t1)=y1 y(t2)=y2 :
. (1.5)
(). 1.1 y(t), y(1)=2 y(3)=0 :
. (1.6)
:
- F(y, y¢);
- F(y, y¢) y y¢;
- (1.2);
- ;
- y(t).
: t0=1, t=3, y(t0) = y0=2; y(t) = yk=0.
F(y,y¢) :
F(y,y¢) = y2 + k2y¢2, =5.
F(y,y¢):
, . (1.7)
г :
2y 2k2y¢¢ = 0 y¢¢- y/k2 = 0 (1.8)
:
(1.9)
, 1 2:
(1.10)
1 = -1,34; 2= 4,43.
:
. (1.11)
1.2, - . 1.2.
|
|
1.2
. | t1,c | t2,c | y1 | y2 |
2.0 | 3.0 | 3.2 | 2.0 |
y(t)
t,c | 1,0 | 1,2 | 1,4 | 1,6 | 1,8 | 2,0 | 2,2 | 2,4 | 2,6 | 2,8 | 3,0 |
y(t) | 2,0 | 1,78 | 1,57 | 1,37 | 1,17 | 0,97 | 0,77 | 0,57 | 0,38 | 0,18 |
³ (1.4) :
, (1.11) (1.6) .
( ) y(t0) = y0, y(t) = yk, , - , (1.2), - (1.3). , .
2 ( )
ᒺ () ᒺ. , ( ), . ᒺ , y(t) ᒺ.
, ᒺ , , :
- ᒺ :
(2.1)
- : y(t0) = y0; y(t) = yk;
- u(t), :
(2.2)
.
. :
(2.3)
l - ;
- ;
- .
(2.2) (1.1). г :
(2.4)
ֳ -. (2.2). ᒺ u*(t) ᒺ .
2.1 f(x1,x2)=(x1-a)2 + (x2-b)2 j(x1, x2) = x12 + x22 R2 = 0. a, b, R 2.1.
2.1
. | a | b | R |
5.5 |
.
f(x1, x2) = 2x12 + x22 :
j(x1, x2) = (x1- 2)2 + x2 = 0.
:
- : F(x1, x2, l) = f(x1, x2) + lj(x1, x2);
- F(x1, x2, l);
- F(x1, x2, l);
|
|
- f(x1, x2);
- .
:
(2.5)
F:
(2.6)
F:
(2.7)
: x1=1; x2= -1; l= 2.
̳ : f(x1, x2) = 2x12 + x22 = 3.
. f(x1, x2) . :
(2.8)
j(x1, x2) . 2.1. (1; -1) f.
2.2 ᒺ, :
, (2.9)
ᒺ : y(0) = y0; y(¥) = 0,
(2.10)
, k, q, c, y0 2.2.
2.2
. | q | c | T | k | y0 |
1,4 |
ᒺ, (2.9) ᒺ : y(0) = y0; y(¥) = 0,
(2.11)
ᒺ (ᒺ ) :
= -1/; b = k/T.
:
(2.12)
:
(2.13)
,
- (2.4):
(2.14)
: u=lb/2, :
(2.15)
, :
(2.16)
:
y(¥) = 0 䒺 , :
(2.17)
1=y(0)=y0.
:
;
:
: (2.17):
(2.18)
(2.19)
г (2.18) ᒺ (2.11). ̳ y(t) u(t) . (2.19) k0.
( ), y(t0) = y0, y(t) = yk ( ᒺ ), , .