东华大学自动控制原理期末复习ppt

– Fuzzy Logics，Artificial Neural Networks， Genetic Algorithm，Artificial Intelligence， Expert System
Types of control systems
按信号的传递路径来分类： –开环控制系统 Open-loop control system –闭环控制系统 Closed-loop control system
按描述系统的数学模型不同来分类: –线性系统 Linear system –非线性系统 Nonlinear system
按系统传输信号的性质来分类: –连续系统 Continuous system –离散系统 Discrete system
Basic requirements (performance)
Basic concept
• The response is composed of the transient response and the steady-state response.
• The transient response is the response that disappears with time (快).
Y(s) R(s)

bmsm ansn

b
sm1
m1

b1s

b0
a
sn1
n 1

a1s

a
0
Laplace transform
Transfer function(2)
Transfer function(3)
Final value theorem
lim y(t) lim sY(s)
Tr 1

2.16 n
0.60
Closeness:
( 2%)
P.O.% exp( / 1 2 )100%
The steady-state error
定义：
ess

lim e(t )
t

lim r (t )
t

y(t)
ess

lim e(t )
t
Stability（稳定性）：先决条件 Accuracy（稳态性）：控制精度 Quickness or Rapidness（动态性）：快速反应
稳！ 准！ 快！
Chapter 2 Mathematical Models of Systems
Differential equation
an
–研究的主要对象是单输入、单输出(One input， One output) —— 单变量系统
Modern control theory (现代控制理论)
–研究的主要对象是多输入、多输出(Multi-input, Multi-Output) ——多变量系统。
Intelligent control (智能控制)
• Inertia components: 1/( Ts +1)
1
• Oscillation component: T 2s2 2Ts 1
• First-order differential component: Ts + 1
• Second-order differential component: T 2s2 2Ts 1
t
s0
微分方程 t
（时域）
L
1
L
系统
F F 1
传递函数
s
（复域）
s j j s
频率特性

（频域）
Typical components
• Proportional component: K • Derivative component: s • Integral component: 1/s
阶跃 斜坡 抛物线
速度 加速度
Performance of a second-order system
Y (s) R(s)

s2

n2 2n s
n2
Underdamped:
0 1
Step response 0 1
Swiftness:
Tr

n
cos1 1 2
• The steady-state response is the response that exists for a long time following any input signal initiation (准).
• The standard test input: The unit impulse, the step input, the ramp斜坡 input, and the parabolic加速度\抛物线 input.
• Time-delay component: es
Block Diagram models
Block diagram reduction
Example:
当系统具有扰动时（输入量以外的信号均为扰动信号）
令N(s) = 0， 令R(s) = 0，
Chapter 5 The Performance of Feedback Control Systems
dn y(t) dtn

a n-1
d n -1 y(t) dt n -1

a1
dy(t) dt

a 0 y(t)

bm
-1
d m-1r(t) dt m-1

b1
dr(t) dt

b 0 r(t)
Transfer function(1)
定义：线性定常系统在初始条件为零时，输出 量的拉氏变换和输入量的拉氏变换之比。
Chapter 1 Introduction to Control Systems
Introduction
Open-loop control system
Closed-loop feedback control system
History of Automatic Control
Classic control theory (经典控制理论)

lim sE(s)
s0

lim s R(s)
s0
Y (s)
H(s) = 1
Chapter 6 The Stability of Linear Feedback Systems
The three approaches to the question of stability