課程名稱︰ 控制系統
課程性質︰ 系定選修
課程教師︰ 陳永耀
開課學院： 電資院
開課系所︰ 電機系
考試日期（年月日）︰2010/11/11
考試時限（分鐘）：180分鐘
是否需發放獎勵金：是
（如未明確表示，則不予發放）
試題 :
NOTE:
(1) Exam starts at 2:20PM,ends at 5:20PM
(2) NO turn-in after 5:10PM
(3) Calculator allowed
(4) Please make sure you put down your name and student ID on the sheet before
turn in it.
(5) Please make sure you turn n all the anwer sheets if they are more than one.
1. For a dynamical system to be controlled to perform a certain task, the first
step is to construct a system model to describe the synamical behavior of the
system.
(a) Usually, the system "input" and "output" have to be defined first. Why and
how? (Please elaborate more on the basic defination of the system input and
the system output.) (10%)
(b) How to tell from a "good" model to a "bad" model? (10%)
2.(a) Please plot the block daigram of a "closed-loop" control system with all
the key words, such as plant, actuator, sensor, controller, comparator,
reference input, output, error, sensor noise, disturbance, used and marked in
the daigram. (10%)
(b) Then please describe the pros and cons of the "closed-loop" control system
to the "open-loop"control system. (Itemized description is most preferred.)
(10%)
3. Give a closed-loop system as in Figure 1 with G(s) to be :
G(s) = (s^2+s+1)/(s^4+4s^3+4s^2+3s+3)
(a) For k=0, please determine the stability of the open-loop system. (5%)
(b) For k=1, please find the pole and zero locations of the closed-loop system
and determine its stability. (10%)
4. (a) Please decribe the design process of a PID control system. (10%)
(b) Specifically, please indicate how you would tune the control parameters and
the reasons for the tunung actions, given the specifications to be:
steady-state error e_ss ≦ 0.1, rise time ≦ 0.1sec, overshoot M_p ≦ 15%,
settling time t_s ≦ 2 sec
and the existing numbers to be:
steady-state error e_ss = 0.3, rise time = 0.1sec, overshoot M_p = 20%,
settling time t_s = 1.8 sec (5%)
(c) What is the phenomenon of "integrator windup"? How does ot affect the
performance of the system? How can the problem be solved? (10%)
5. Short Questions (Please determine if the following statments are correct or
false. Please also provide explanations on your answers.) (5% each, 20% in
total)
(a) A unity-feed back system as in Figure 1 is always stable with stable
open-loop system G(s).
(b) The closed-loop system can always achieve better steady-stae error
performance than the open-loop system.
(c) A dynamic system is stable if there are no poles in the left-half plane.
(d) If System A has a damping ratio 0.25 and a natural frequency 10 rad/sec
which are both half as large as the ones with System B. Please estimate the
ratio between the settling time of System A, t_sA, to the settling time of
System B, t_sB. (Please refer to Figure 2)
r e ┌──┐ u ┌──┐ y
──→○─→│ K │──→│G(s)│─┬→
+ ↑- └──┘ └──┘ │
└──────────────┘
Figure 1
Figure 2 in text book P.97 Figure 3.22
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※ 編輯: DOMENKING 來自: 140.112.4.185 (11/11 17:06)