《自动控制原理》试卷及答案(英文10套)

AUTOMATIC CONTROL THEOREM (5)

⒈ Consider the system shown in Fig.1. Obtain the closed-loop transfer function

C(S)E(S), . （18%） R(S)R(S) H2

E R G1 G2

H1

H4 Fig.1

⒉ The characteristic equation is given

C G3 H3 1?GH(S)?S5?3S4?12S3?24S2?32S?48?0. Discuss the distribution of the closed-loop poles. (16%)

⒊ Sketch the root-locus plot for the system GH(S)?K. (The gain

S(S?1)(0.5S?1)K is assumed to be positive.)

① Determine the breakaway point and K value.

② Determine the value of K at which root loci cross the imaginary axis. ③ Discuss the stability. (18%)

⒋ The system block diagram is shown Fig.2. G1?K1K2, G2?. ①T1S?1T2S?1Suppose r?0, n?1. Determine the value of eSS. ②Suppose r?1, n?1. Determine the value of eSS. (14%)

N R E C G1 G2 Fig.2

⒌ Sketch the Bode diagram for the following transfer function. GH(s)?K,

s(1?Ts)K?7, T?0.087. (10%)

⒍ A system with the open-loop transfer function GH(S)?K is inherently 2s(TS?1)unstable. This system can be stabilized by adding derivative control. Sketch the polar plots for the open-loop transfer function with and without derivative control. (14%)

⒎ Draw the block diagram and determine the transfer function. (10%)

R C U2(s) U1(s)

⒈

C(S)G1G2G3? R(S)?⒉R=0, L=3,I=2 ⒋①ess??K21?K2②ess?

1?K1K21?K1K2⒎

U2(s)1? U1(s)RCs?1

AUTOMATIC CONTROL THEOREM (6)

⒈ Consider the system shown in Fig.1. Obtain the closed-loop transfer function

C(S)E(S), . （18%） R(S)R(S)C E R G1 G2 H1 H2 H3

⒉The characteristic equation is given

Fig.1 1?GH(S)?25S5?105S4?120S3?122S2?20S?1?0. Discuss the distribution of the closed-loop poles. (12%)

⒊ Sketch the root-locus plot for the system GH(S)?K(S?1). (The gain K is

S(S?3)assumed to be positive.)

① Determine the breakaway point and K value.

② Determine the value of K at which root loci cross the imaginary axis. ③ Discuss the stability. (15%)

⒋ The system block diagram is shown Fig.2. G1?101, G2?. Suppose

S(0.25S?1)Sr?1?t, n?0.1. Determine the value of eSS. (12%) R E

N G1 0.5 G2 C Fig.2