当前位置:首页 >> 农林牧渔 >>

PIS-08


Principles of Information Science

Chapter 8
Principles of Information Execution: Control Theory

1, Classical Theory of Control

Simplest Model of Contro

l System
N. Wiener: Control theory in engineering, whether it is concerned with man, animal or machine, can only be regarded as a part of information science.

I(G) Controller I(O,N) Object Noise I(O, N, G, K)

Description of Controlled Object
Object Description: The states, The Ways of states vary

s1 … t1 . . . tM x1 xM

sN

s1 s1

s2

s4 y1 yN

s3

T

P(11) … P(14) … … P(41) … P(44)

Description of Goal and Effect

The initial condition, s, of the controlled object and the final condition, g, are s two states of the object in the state space of control problem. The path connecting all the states from s to g is the one the possible solutions for the control problem. In an N dimensional space, the states and the control effect can be described as s={s1, …, sN}, g={g1, …, gN} __ 2 ε = [ ∑ (gn – g’n)2 ]1/2
n

g

The Mechanism of Control
Mechanism of Control: from Information to Action

Strategy Information Execution Action Object

The Categories of Control
Open-Loop

Noise

Controlling

Execution

Object

Closed-Loop Goal Noise Controlling Execution Object

Effect

Deterministic Strategy to Control Strategy
Mathematical Programming: Strategy Producing

X – N dimensional column vector f(X) – dependence relationship between goal and the system states g(X) – environment constraints of the system

The optimum control strategy can be produced through the maximizing (minimizing) the goal function under the given constraints: Max(Min) f(X)
{g(X)}

An Example: Linear Programming
Goal function: f = 5 x1 + x2 Constraints: (1) x1 ≥ 0; (2) x2 ≥ 0; (3) x1 + x2 ≤ 6; (4) 3 x1 + x2 ≤ 12; (5) x1 – x2 ≤ 2. Solution: x2 A (2) (3) B (4) (5) D C x1

f

Fmax = 136/7

Point C: x1 = 26/7 x2 = 6/7

O (1)

Other Approaches

Non-Linear Programming Integer Programming One dimensional Search Higher dimensional search Dynamic Programming, etc.

2, Intelligent Control

Intelligent Approach to Control Strategy

Goal
Comm. Cog. + DM Comm.

Sensing

Object Noise

Controller

Adaptation & Learning: Concepts
Terminologies & Definitions E—environment; P—performance; S—system; T– time span. E changes while P stays in a prescribed range, S is then stable. S changes while P stays in a prescribed range, S is reliable. E & structure of S changed while P is still satisfactory, S is said adaptive. E changed and P meets requirements after T, S is said a learning system. Structure changed yet P meets requirements after T, S is said a self-repaired system.

Adaptation: Model
It is request that X(t) properly responds to an unknown V(t). V(t) Adaptive Algorithm W(t) V(t) Variable Controller u(t) Object X(t) P(t) Performance Judgment

X(t) is compared to V(t) and producing P(t), then controller is adjusted based on W(t), which is the output of adaptive algorithm driven by P(t).

Information Threshold

The goal of control: H(X|Y) = 0 From I(X;Y) = H(X) – H(X|Y) we have X H(X|Y) = H(X) – [H(Y) – H(Y|X)] = H(Y|X) + H(X) – H(Y) Object Controller Y

N Since H(Y|X) ≥ 0, in order to make H(X|Y) = 0, there must be H(Y) ≥ H(X) = H(N)

Information Criterion for Control Strategy
Assume that among M possible states in search space, the present state is Xmo, and goal state is Xmg. If I(ζm(k+1) ) > I(ζmk) > … > I(ζmo ), search continues; ζ ζ ζ Otherwise, search stops. The optimum solution can be obtained by the calculation: I(ζmk0 ) = Max I(ζmk ) ζ ζ
k

Partial Summary

Processing Ch.6

Conversions-1 Ch. 7-1

Conversions-2 Ch. 7-2

Transferring Ch.5

Ch.9, 10

Transferring Ch.5

Acquisition Ch.4

The World Ch. 1, 2, 3

Execution Ch. 8

Principles of Information Execution
1. The essence of information execution is to converse strategic information into corresponding action in practice. 2. The strategy generation is feasible in most cases if the Goal is rational and the knowledge for problem-solving are necessary and sufficient. 3. As the product of information, strategy is theoretically executable as the strategy clearly tells what states the system should stay and how to move the current state to the one desired. 4. The strategy is practically executable via the mapping between strategy to action – the information-to-energy conversion. 5. Whether the control system can successfully perform its function under disturbance depends on the system’s stability, adaptability, knowledge availability and the criterion of Information Threshold maintainability.

Exercises

1. Please give your own explanation on the mechanism for information-action conversion. 2. Try to prove the “Information Threshold Criterion” in the designing of control systems. 3. Do you agree the saying that control theory is a part of information science? Why and why not?


相关文章:
山大08系解A
山大08系解A_临床医学_医药卫生_专业资料。山东大学医学院(2009——2010 学年...the palmaris longus attaches to the pisiform bone 7. Which statement is ...
常用单位换算
39.371 1 12 ft(foot 呎) 0.00328 0.03281 3.28091 0.08333 1 2....流量 Cv 值=水流量(US gal/min)于 60℃下,流经差压力 1pis 之阀门而所...
AT指令错误代码意义
将目的号码字符串后的第二个字节设成 08,将转 换好的 Unicode 编码中文短...NSAPIs 618 GPRS - processing of multiple cids not supported 619 GPRS - ...
经典手机铃声下载地址大全
//www.tudou.com/v/sDKtsSZJR08 http://www.tudou.com/v/L1r_hv-axZg ...//www.tudou.com/v/KtjDd2PisVU http://www.tudou.com/v/0xGOmX3ut_Q...
日汉建筑用语
pishui waiguan chunjingcailiao qiefeng 取手 ドレ一ン 流台 二重壁 軒 軒...文档贡献者 tuvshin 贡献于2010-08-26 文库认证 建筑工程资料(全套) 2014年...
08机电《电工基础》试卷
08机电《电工基础》试卷_理化生_高中教育_教育专区。高一机电专业第三次月考《...PE=4W 产生 PIS=8W 消耗 C.4 和 3 ( D.4 和 2 ) 9、R1、R2 两...
个人简历-4
Etiam at posuereturpis, vitae gravida ligula. In lacus dolor, luctuseget...文档贡献者 夏阅夜 贡献于2017-01-08 1/2 相关文档推荐 个人简历4 暂无评价...
生活单词表
bitter 北杏/苦杏仁 almond 榛果/榛仁 开心果 hazelnut pistachio / pis'tɑ...文档贡献者 黑色贝克 贡献于2015-08-05 专题推荐 2014下半年教师资格...专题...
SDI测定方法
(如果 整定值达不到 30PIS 时,则可在现有压力下试验,但不能低于 15Psi) ...文档贡献者 孟颖11 贡献于2012-08-28 1/2 相关文档推荐 污染指数(SDI)测定...
08电路模拟试卷解答
08电路模拟试卷答案08电路模拟试卷答案隐藏>> 一.分析下列各题 (28 分) 1.求...?30 W PIS2 ? 12 W PIS 3 ? 16 W PUS1 ? 20 W PUS2 ? ?18 W ...
更多相关标签: