computer control technology hesheng wang department of automation,sjtu sept.2011
TRANSCRIPT
Computer Control TechnologyComputer Control Technology
Hesheng Wang Hesheng Wang Department of Automation,SJTUDepartment of Automation,SJTU
Sept.2011Sept.2011
Chapter 1 Overview
OutlineOutline
1. Course objectives and tasks2. The main content3. The main References4. The concept of computer control system5. Computer Control System ‘s Structure6. Typical Forms
7. Control law
1 Course objectives and tasks(1/2)
Industrial control is an important application field of computer, the computer control is developed in order to meet the needs of this field and a professional technology 。
Task: it mainly studies how to apply computer technology and automatic control theory in industrial production process, and designed a computer control system that is needed.
Purpose: it is to make students understand and master the single-chip as the core of the control system of hardware, software, the basic knowledge and basic application technology.
1 Course objectives and tasks (2/2)
This course is one of the professional basic courses
and professional backbone course of the
automation.
what course ？ The automatic control theory, modern control
theory, computer theory and interface technology,
computer control technology, motion control
systems, process control systems.
2 The main content（ 1/4 ） The main contents of the course include ：
The composition and classification of the computer control
system ；
Computer control system design method of the process channel ；
Digital process control technology ；
Digital PID algorithm ；
Direct digital control algorithm ；
Model predictive control algorithm;
Distributed Computer Control System ；
Fieldbus technology
2 The main content （ 2/4 ）Overview and process channel modules
An overview of the computer control system
Process channel and data acquisition system
Process control and numerical control
The main content （ 3/4 ）Algorithm module Digital PID control algorithm Direct digital controller design
method Model predictive control algorithm
2
2 The main content （ 4/4 ）Advanced control module Microcomputer control system
design and application examples Distributed Computer Control
System Fieldbus technology and
applications
3 The main References
Author Title Press Year
XIE Jianying et al.
Micro-computer control technology (3rd edition)
National Defense Industry Press
2001
XI Yu-Geng et al.
Predictive Control National Defense Industry Press
1991
Jin Yihui et al.
Process Control Tsinghua University Press
1995
Yu Haisheng et al.
Microcomputer control technology Tsinghua University Press
1999
Zeng-Qi Sun et al.
Computer Control Theory and Applications
Tsinghua University Press
Modern computer control system
4 Computer control concept(1/3)
The computer control system is the use of the computer to achieve automatic control system of the production process. The computer control system (including hardware, software and network structure) is composed of two parts including the controlled objects and the computer body . The following figure is a typical deviation control computer control system.
y控制器
-被控对象
e给定量执行机构+
rD/A
被控量
测量变送
u
A/D
生产过程工控机
Controller (Computer)
controlled object (The production process)
Controller-
eInput +
rD/A
u
A/D
IPC
y
Controlled object
actuatorOuterput
Measuring transducer
Process of production
Controller-
eInput +
rD/A
u
A/D
IPC
y
Controlled objectactuator
Output
Measuring
transducerProcess of production
Controller
(Computer)
Controlled object
(Process of production)
4 The concept of computer-controlled system（ 2/3 ）
In the structure can be divided into open loop systems and
closed-loop system
◆ Open-loop: simple structure, poor performance
◆ Closed loop: the need of the feedback signal of the controlled object
The control procedure (4) ： ◆ Real-time data acquisition
◆ Real-time computing
◆ Real-time control
◆ Information management
4 The concept of computer-controlled system(3/3)
A few common terms
◆ Online： Computer control system is directly connected with the
production equipment
◆ Offline： The computer control system is disconnected with the
production equipment ◆ Real time： Computer input, output, and calculations are completed
within the specified time
◆ The relationship between online and real-time
— An online system is not necessarily real-time systems
— A real-time system must be online system
5 Composition of the computer control system(1/4)
Hardware components
◆ Host computer ： CPU 、 RAM / ROM
◆ Regular peripherals ： Input, output and storage
devices
◆ Input and output channels ： AI、 AO、DI、DO
◆ Peripheral ： Various interfaces(Universal)
◆ Run console ：Display, function keys, numeric
keys
5 Composition of the computer control system(2/4)
Computer control system hardware block diagram
Printer
Display terminal
Disk drive
Software
Microcomputer
Realtime clock
Work station
Interface
Interface
Interface
Interface D\ A
A\ D Multiplexer
Anti-multiplexer
Switch input
Switch output
actuator The production objec
t
external devices The host and the work station
Outer channelInterfaceDetection and transmission
Control object
SensorTransmitter
5 Composition of the computer control system(3/4)
Software components
◆ System Software
—Basic computer operation and
management environment
◆ Application software
— Direct control program
5 Composition of the computer control system（ 4/4 ）
Network Structure
◆ Peer-to-peer network structure （ Peer-to-
Peer, P2P ）
— Peer-to-peer networking technology ◆
Client / server architecture （ Client/Server, C/
S ）
— Each node function is different
6 Typical forms of computer control system(1/6) Data acquisition and monitoring system: the computer is not
directly involved in the control process.
Display terminal
Printer
Sam
ple
r
Com
pute
r
A / D
co
nverte
r
Measu
ring
ele
ment
Ind
ustria
l obje
cts
6 Typical forms of computer control system(2/6)
Direct Digital Control, DDC — Computer participate in the closed loop
control process Management Command
DDC Mi crocompu
ters
Report
Arti fi ci al regul atory
Gi ven val ue
Measured val ue
A/ D
Mul ti pl exer
Detecti ng el ement
D/ A
Anti -mul ti pl exer
Process of producti on
6 Typical forms of computer control system（ 3/6 ）
Supervisory Computer Control, SCC
— Given value control, the effect depends on the
accuracy of mathematical model
— Two different structures ：
• SCC＋ Analog regulator
• SCC＋ DDC
6 Typical forms of computer control system （ 4/6 ）
SCC＋ Analog regulator SCC＋DDC
管理命令 报告
人工监管
给定值 测量值
A/D
多路开关
检测元件
生产过程
管理命令 报告
人工监管
给定值 测量值
A/D
多路开关
检测元件
生产过程
DDC
D/A
反多路开关
. .
.
. .
. .
.
Management Command
Report
Artificial regulatory
Given value
Measured value
Multiplexer
Detector
Process of production
Management Command
Report
Artificial regulatory
Given value
Measured value
Multiplexer
Detector
Anti-multiplexer
Process of production
6 Typical forms of computer control system （ 5/6 ）
Distributed Control System, DCS — Decentralized control and centralized
managementEnterpri se-cl ass
Operati on and management of computer
Pl ant l evelCentral i zed control of
the computer
The workshop l evel moni tori ng computer（SCC）
The workshop l evel moni tori ng computer （SCC）
Devi ce control l evel （DDC）
Devi ce control l evel （DDC）
Devi ce control l evel （DDC）
Factory obj ect A Factory obj ect B Factory obj ect C Factory obj ect D
To other pl antsTo other pl ants
Devi ce control l evel （DDC）
6 Typical forms of computer control system （ 6/6 ）
Fieldbus Control System, FCS
◆ A new generation of distributed control structure
◆ With "workstations and field bus instrument" layer
structure complete DCS three-tier structure function ◆ Can reduce costs, improve reliability, realize the
real open interconnection system structure
7 The control law of Computer control system 1/4
Sequence control and numerical
control ◆ Belongs to open loop control mode
◆ Sequence control: according to certain time
sequence and logical order
— Timing control
— Logic control
◆ Numerical control ： according to the given data to
a certain procedure to control
7 The control law of Computer control system（ 2/4 ）
PID Proportional-Integral-Differential ） ◆ According to the deviation of the proportional, integral and differential control
◆ Algorithm is simple, the most mature technology in the continuous system, the most
widely used
Direct digital controller design algorithm
— Based on Z transform, sampling control system
Model predictive control
— Control algorithm based on system input and output
7 The control law of Computer control system（ 4/4 ）
Intelligent control
◆ fuzzy control
◆ Expert system
◆ learning control
◆ Neural network control
7 The control law of Computer control system(3/4)
The optimal control
— The choice of appropriate control law, the working conditions of the control system of constant and certain physical statistics under the restrictions of the system of some performance index, evaluation function to obtain the maximum or minimum value.
Adaptive control
— Designed controller can still can make the performance
evaluation function to achieve the optimal under the condition of the statistical change.
8 Control device types
1 Programmable controller
2 Programmable regulator
3 Bus industrial control
4 single chip microcomputer
5 Other control devices
8.1 Programmable controller
The programmable logic controller -- Referred to as the programmable controller or PLC, is the product of the combination of computer technology and the concept of relay logic control, low-end alternative of the conventional relay logic control device, the high-end for a high-performance industrial control computer. It mainly consists of a CPU, memory, input components, output components, power supply and programmer. Appearance as shown.
Programmable Logic Controller （ PLC） features ：
A digital electronic computers operating system, designed for industrial environment applications and settings;
Using programmable memory, performing logic operations in its internal storage, sequence control, timing, counting and arithmetic operation instruction, and through digital and analog inputs and outputs.
Wide range of applications - not only has the advantage in the field of sequential program control, and motion control, process control, network communication areas favorably;
PLC system is a flexible, easy expansion, simple programming, easy to debug, anti-interference ability;
8.2 Programmable regulator Programmable regulator-- Also known as single-loop controller, intelligent regulator, digital regulator. It consists predominantly of micro-processing unit, the process I / O (input / output) unit, the panel unit, the communication unit, a hard hand operation unit and the programming unit and other components. Appearance as shown.
Programmable regulator features ：
An instrumented micro-control computer Easy to operate, easy to program, convenient and flexible Designed without considering the hardware design of the
interface, communication Just use a problem-oriented configuration language software
programming Power protection, self-diagnostic function, communications and
other functions To form a multi-level computer control system, to achieve a variety
of advanced control and management the most basic control unit in Large-scale distributed control
system Suitable for analog signal in a continuous process control system
8.3 Bus IPC Bus IPC, is based on the the versatility computer bus technology and the modular structure of a special industrial control, commonly
referred to as industrial control computer, referred to as industrial
control machine or IPC.
Bus IPC miniaturization, template, combination, standardized design
features to meet the needs of different levels and control object, and can
operate reliably in harsh industrial environments. Thus, it is widely used in
a variety of control applications, in particular, is more than a dozen to
several tens of medium-sized loop control system.
8.4 Single chip microcomputer Ultra miniaturization of Single Chip
Microcomputer (Single Chip Microcomputer) hereinafter referred to as SCM was born. It is the CPU, memory, string parallel I/O port, timer/counter and A/D converter, the pulse-width modulator, the graphics controller features are all integrated on A large scale integrated circuit chip, constitute A complete fairly control function of the microcontroller.
Because the SCM has small volume, low power consumption, reliable performance, low cost, easy function extension, use convenient and flexible, easy to production, and many other advantages, especially the powerful control oriented ability, make it in the industrial control, intelligent instruments, peripherals, household appliances control, robotics, military equipment is widely used.
8.4 Single chip microcomputer
8.5 Other control devices
Distributed control system and fieldbus control system
--Initially,it is in the form of a control program,
but soon greatly respected by the industrial market,
which has become home and abroad automation
manufacturers are scrambling to offer two typical
device.
SummarySummary1. Course objectives and tasks2. The main content of this course3. The main reference literature4. The concept of computer control system
• Control system, open loop closed-loop, offline, online, real time, controls four tasks
• Composition of the computer control system• Hardware, software, hosting, interface, channel, testing
to change devices, peripherals, work station, object5. Typical forms of computer control system6. monitoring, DDC, SCC(SCC＋ Analog regulator, SCC+DCC),
DCS, FCS7. Control law of the computer control system 8. Control device types