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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