现代控制理论习题答案(2)
第二章
0102-3 已知矩阵A001,试用拉氏反变换求eAt 2540s1s1 解:sIA025s4
s24s5s41
1
(sIA)12s(s4)s(s1)2(s2)2
2s25ss
21(s1)2s2
222
(s1)2s1s2244
2
s1s2(s1)
322
(s1)2s1s2354
(s1)2s1s2388
(s1)2s1s2
122
2(s1)s1s2
122
(s1)2s1s2134
2
(s1)s1s2
s24s5s41
1
(sIA)12s(s4)s(s1)2(s2)2
2s25ss
21(s1)2s2
222
(s1)2s1s2244
2
s1s2(s1)
322
(s1)2s1s2354
(s1)2s1s2388
(s1)2s1s2
3tet2et2e2t3tet5et4e2t3tet8et8e2t
122
(s1)2s1s2
122
2
(s1)s1s2134
(s1)2s1s2
tetete2t
tet2et2e2t tet3et4e2t
eAtL1(sIA)1
2tete2t
2e2t2tet2et2tet4et4e2t
2-4 用三种方法计算以下矩阵指数函数eAt, (1) A
01
40
解:(1)化为约旦标准型
IA
12
40 12j,22j
4
1
1
1
T112j2j
T1
2
114j 2
4j
2jt
eAtTT
1
1
1e01
14j2j2j0
e2jt21
12
4j
1
(e2jte2jt)1j(e2jte2jt)2412jt2jt1cos2tj(ee))2(e2jte2jt
)
2sin2tcos2sin2t2t
(2)拉普拉斯变换
sIAs11s4s
(sIA)1
s1s2
44ss244s24
eAtL1(sIA)1
cos2t1sin2t
2sin2tcos22t
(3)凯莱-哈密顿定理
1
2jt1
12je1
0212j2jt12e2jte2jtcos2t1
e1
4
j4j
12sin2t
eAt10101
0I1Acos2t012sin2t40
cos2t1sin2t
2sin2tcos22t
(2) A11
41
1(ete3t
1解:(t)
2
)4(ete3t)t3t
1
(ee)(et
e3t2)
2
1s2s4s24
2-5 下列矩阵是否满足状态转移矩阵的条件,如果满足,试求出与子对应的A阵
1(2)(t)
1
2
(1e2t)
0e2t
1(et3t
1(et(4)(t)
2
e)4
e3t)1
(ete3t
)2(ete3t
)
状态转移矩阵的条件
(t)A(t)
(0)I
(t)()(t)
求取A的方法:
L((t))(sIA)1(t)A(t)(t)AA(t)
t0
解
(2)此矩阵是状态转移矩阵
11(11L((t))s2ss2)
01
s2
(sIA)1
1111(sIA)s(s2)
s2
2(s)1
2s
0s
s10s2
(4)此矩阵是状态转移矩阵
1111L((t))1
2(1
s1s3)4(s1s3)
1s11s3
)112(s11s3)
1s11(s1)(s3)4s1
(sIA)1
3
A0102
s1111
sIAA
4s141
2-6 求下列状态空间表达式的解
010xxu001 y10x
解:A
01
00
1
s2 1s
1
s11s1s1
(sIA)sIA2s0s00s
1t
eAtL1(sIA)1
01
x(t)eAtx0(t)Bu()d
t
1t1t1t01ttt
d1001101d 011
221tt1tt
22
1t1t
2-7 试证本章2-3,在特定控制作用下,状态方程式(2-25)的解,式(2-30),式(2-31)和式(2-32)成立
(2)u(t)k(t),x(0)x0
x(t)eAtx0eA(t)BK()d
t
ex0eA(t)BK()d
At
0
eAtx0eAtBK
(3)u(t)K1(t),x(0)x0
4
(4)u(t)
Kt1(t),x(0)x0
2-9
根据系统的方框图可得
1x1ku1x
2x1u2 x
y2x1x2
110x1k0xx10x01u22
x
y211
x2eAtL1(sIA)1
s1011s011
LL1s1s1s(s1)1
11
s1L
11s(s1)
ss1
01s
ett1e
0
1
G(T)e
AT
eTT1e0 1
5
k0
B
01HedtB
0T
AT
T
eTT1e0k0dt101
T
1eTT1e
当T=0.1时
T
0k0k(1e)0
T01k(T1eT)T
e0.10
G(T)G(0.1) 0.1
11e
k(1e0.1)0
H(T)H(0.1) 0.1
k(0.9e)0.1
当T=1时
e10
G(T)G(1) 1
11ek(1e1)0
H(T)H(0.1) 1
1ke
2-11
根据上面的模拟结构图,求去连续的状态方程,进而化成离散状态方程。
6