Automation Hierarchy 1.4 Hiérarchie de l`automation Leitsystem

Transcription

Industrial Automation
Automation Industrielle
Industrielle Automation
Enterprise
Manufacturing Execution
Supervision (SCADA)
Group Control
Individual Control
Field
Primary technology
1.4
Automation Hierarchy
Hiérarchie de l'automation
Leitsystem-Hierarchie
Prof. Dr. H. Kirrmann
EPFL / ABB Research Center, Baden, Switzerland
2011 February, HK
1.4 Contents
1 Introduction
1.1
Automation and its importance
1.2
Examples of automated processes
1.3
Types of plants and controls
1.3.1
Open loop and closed loop control
1.3.2
Continuous processes
1.3.3
Discrete processes
1.3.3
Mixed plants
1.4
Automation hierarchy
1.5
Control system architecture
2
1.4 Automation hierarchy
Automation System Structure
Although applications differ widely, there is little difference in the overall architecture
of their control systems.
Why the control system of a power plant is not sold also for automating a brewery
depends largely on small differences (e.g. explosion-proof devices), on regulations
(e.g. Food and Drug Administration) and also tradition, customer relationship.
But the biggest difference is the amount of application know-how embedded in the
control system.
3
Large control system hierarchy (1)
5
Planning, Statistics, Finances
4
Production planning, orders, purchase
3
Workflow, order tracking, resources
2
Supervisory
administration
enterprise
(manufacturing) execution
SCADA =
Supervisory Control
And Data Acquisition
Group control
Unit control
1
Field
Sensors
& actors
0
A V
T
Primary technology
4
Large control system hierarchy (2)
Administration
Enterprise
Manufacturing
Supervision
Group (Area)
Unit (Cell)
Field
Finances, human resources, documentation, long-term planning
Set production goals, plans enterprise and resources, coordinate
different sites, manage orders
Manages execution, resources, workflow, quality supervision,
production scheduling, maintenance.
Supervise the production and site, optimize, execute operations
visualize plants, store process data, log operations, history (open loop)
Controls a well-defined part of the plant
(closed loop, except for intervention of an operator)
•
Coordinate individual subgroups
•
Adjust set-points and parameters
•
Command several units as a whole
Control (regulation, monitoring and protection) part of a group
(closed loop except for maintenance)
•
Measure: Sampling, scaling, processing, calibration.
•
Control: regulation, set-points and parameters
•
Command: sequencing, protection and interlocking
. transmission
data acquisition (Sensors & Actuators), data
no processing except measurement correction and built-in protection.
5
Field level
the field level is in direct
interaction with the plant's hardware
(Primary technology, Primärtechnik)
6
Group level (Area)
unit controllers
the group level coordinates the
activities of several unit controls
the group control is often hierarchical, can be
also be peer-to-peer (from group control to
group control = distributed control system)
Note: "Distributed Control Systems" (DCS)
commonly refers to a hardware and software
infrastructure to perform Process Automation
7
Local human interface at group level
sometimes,
the group level has its own
man-machine interface for
local operation control
(here: cement packaging)
also for maintenance:
console / emergency panel
8
Supervisory level: Man-machine interface
control room
(mimic wall)
1970s...
formerly, all instruments were directly wired to the control room
9
Mosaic is still in use – with direct wiring
10
Supervisory level: SCADA
(SCADA = Supervisory Control and Data Acquisition)
Trend e
rapporti
Interfaccia
operatore
Gestione
ricette
Base dati
di processo
Controllo
di processo
Gestione
allarmi
Supporto
manutenzione
Sistema
esperto
OPC
- displays the current state of the process (visualization) and can modify it (process control)
- displays the alarms and events (alarm log, logbook “giornale di bordo”)
- displays the trends (historians) and analyse them
- displays handbooks, data sheets, inventory, expert system (documentation)
- manages maintenance and working plans (recipes)
- allows communication and data synchronization with other centres
11
Today’s control rooms
beamers replaces the mosaics, there is no more direct wiring to the plant.
12
Plant management
- store the plant and product data for further processing in a secure way
(historian), allowing to track processes and trace products
-> Plant Information Management System (PIMS) sistema informativo
- make predictions on the future behaviour of the processes and in particular
about the maintenance of the equipment, track KPI (key performance indicators)
-> Asset Optimisation (AO) ottimizzazione delle attività
13
Engineering workplace
The engineering workplace manages the control system, not the plant.
The engineer can configure the networks and devices, load the software, assign
authorizations, troubleshoot the control system,...
14
ANSI/ISA 95 standard classification
the ANS/ISA standard 95 defines terminology and good practices (procedures, benchmark)
Level 4
Business Planning & Logistics
Enterprise Resource Planning
Plant Production Scheduling
Operational Management, etc.
Level 3
Manufacturing
Operations & Control
Dispatching Production, Detailed Product
Scheduling, Reliability Assurance,...
Levels
2,1,0
Batch
Control
Continuous
Control
Discrete
Control
Manufacturing Execution System
Control & Command System
Source: ANSI/ISA–95.00.01–2000
15
Example: Power plant
16
Example of generic control siemens: Siemens WinCC (Generic)
Unternehmensleitebene
Enterprise level
Betriebsleitebene
Production level
Prozessleitebene
Process level
17
Response time and hierarchical level
ERP
Planning
Level
(Enterprise Resource
Planning)
MES
Execution
Level
(Manufacturing
Execution System)
SCADA
(Supervisory Control
and Data Acquisition)
Supervisory
Level
DCS
(Distributed
Control System)
Control
Level
Note:
a complex and powerful PLC
has the same HW than a DCS
PLC
(Programmable
Logic Controller)
ms
seconds
hours
days
18
weeks
month
years
Data Quantity & Quality and Hierarchical Level
Higher Levels
When ascending the control hierarchy, data are reduced:
higher level data are created (e.g. summary information)
Processing and decisions becomes more complicated (requires using models).
Timing requirements are slackened. Historical data are stored
SCADA level
Presentation of complex data to the human operator,
aid to decisions (expert system) and maintenance.
Requires a knowledge database in addition to the plant's database
Lower Levels
Lowest levels (closest to the plant) are most demanding in response time.
Quantity of raw data is very large.
Processing is trivial (was formerly realized in hardware).
These levels are today under computer control,
except in emergency situations, for maintenance or commissioning.
19
Complexity and Hierarchical level
Complexity
Reaction Speed
months
ERP
MES
Command level
Führungsebene,
Sys. d'exécution
Ausführungssystem
Supervision
étage de conduite
Prozessleitung
Conduite de processus
Group Control (area)
Gruppenleitung
Conduite de groupe
Individual Control (Cell)
Einzelleitung,
days
minutes
seconds
0.1s
Conduite individuelle
Field
Feld,
0.1s
terrain campo
Site
Anlage,
usine
20
dispositivi
Operation and Process Data base
Consideration of human intervention breaches this hierarchy.
Normally, the operator is only concerned by the supervisory level,
but exceptionally, operators (and engineers) want to access data of the lowest levels.
The operator sees the plant through a fast data base, refreshed in background.
This database is the pivot for logging and simulation.
knowledge base
man-machine
communication
operator
history
logging
process
data base
simulation
instructor
maintenance
engineer
actualization
process data
plant
21
The process database is at the centre (example: Wonderware)
22
Process Data Base and Historical Data Base
The Process Data Base reflects the latest known state of the plant
The Historical Data Base registers the events that happened in the plant
(and is therefore a subset of the Process Data Base snapshot)
“Compression” problem
“Data find and data recovery” problem
“The digital dark age” problem (obsolescence of supports or formats)
E.g. the “compression” problem applied to a trend
- compression in data (less information, less resolution)
- compression in time (undersampling)
Solutions that compress data (source, ID, mean value, median value, standard deviation, min
& max, date & time) for a variable time (small time during events, long time in steady-state)
23
SCADA
Acronym for Supervisory Control and Data Acquisition a computer system for gathering and
analyzing real time data, SCADA systems are used to monitor and control a plant or equipment
in industries such as telecommunications, water and waste control, energy, oil and gas refining and
transportation, building and home.
A SCADA system gathers information, such as where a leak on a pipeline has occurred, transfers
the information back to a central site, alerting the home station that the leak has occurred, carrying
out necessary analysis and control, such as determining if the leak is critical, and displaying the
information in a logical and organized fashion.
SCADA systems can be relatively simple, such as one that monitors environmental conditions of a
small office building, or incredibly complex, such as a system that monitors all the activity in a
nuclear power plant or the activity of a municipal water system.
In many industrial applications, SCADA are commonly used for HMI, alarms, trends and reports,
process controls, maintenance actions, working plans and recipes, statistical analysis and expert
systems, and other functions.
Nowadays solutions benefit from a single, open and scalable software architecture that can connect
to virtually any automation system, remote terminal unit (RTU), intelligent electronic device (IED),
programmable logic controller (PLC), database, historian or business system in use today.
www.plcscada.com
24
SCADA
www.plcscada.com
25
PLC
The PLC (Programmable Logic Controller) was invented in response to the needs of the American
automotive manufacturing industry. PLCs were initially adopted by the automotive industry where
software revision replaced the re-wiring of hard-wired control panels when production models
changed.
Before the PLC, control, sequencing, and safety interlock logic for manufacturing automobiles was
accomplished using hundreds or thousands of relays, cam-timers (timer multipli a motore), and drum
sequences (sequenziatori a tamburo) and dedicated closed-loop controllers. The process for
updating such facilities for the yearly model change-over was very time consuming and expensive,
as electricians needed to individually rewire relays.
In 1968 GM Hydramatic (the automatic transmission division of general motors) issued a request for
proposal for an electronic replacement for hard-wired relay systems. The winning proposal came
from Bedford Associates of Bedfors, Massachusetts. The first PLC, designated the 084 because it
was Bedford Associates' eighty-fourth project, was the result. Bedford Associates started a new
company dedicated to developing, manufacturing, selling, and servicing this new product: Modicon,
which stood for MOdular DIgital CONtroller. One of the people who worked on that project was Dick
Morley, who is considered to be the "father" of the PLC. The Modicon brand was sold in 1977 to
Gould Electronics,and later acquired by German Company AEG and then by French Schneider
Electric, the current owner.
One of the very first 084 models built is now on display at Modicon's headquarters in North Andover,
Massachusetts. It was presented to Modicon by GM, when the unit was retired after nearly twenty
years of uninterrupted service. Modicon used the 84 moniker at the end of its product range until the
984 made its appearance.
The automotive industry is still one of the largest users of PLCs.
www.plcscada.com
26
PLC
• Compact, robust and nice
• modular architecture
• well-connected and integrated
• programmable
www.plcscada.com
27
DCS
Distributed Control Systems (DCSs) are dedicated systems used to control manufacturing
processes that are continuous or batch-oriented, such as oil refining, petrochemicals, central
station power generation, pharmaceuticals, food and beverages ,manufacturing production,
steelmaking, and papermaking.
Similarly to PLCs, DCSs are connected to sensors and actuators and use setpoint control to
control the flow of material through the plant. The most common example is a setpoint control
loop consisting of a pressure sensor, controller, and control valves. Pressure or flow
measurements are transmitted to the controller, usually through the aid of a signal conditioning
Input/Output (I/O) device. When the measured variable reaches a certain point, the controller
instructs a valve or actuation device to open or close until the fluidic flow process reaches the
desired setpoint. Large oil refineries have many thousands of I/O points and employ very large
DCSs. Processes are not limited to fluidic flow through pipes, however, and can also include things
like paper machines and their associated variable speed drives and motor control centers, cement
kilns, mining operations, ore processing facilities, and many others.
A typical DCS consists of functionally and/or geographically distributed digital controllers capable of
executing from 1 to 256 or more regulatory control loops in one control box. The input/output
devices (I/O) can be integral with the controller or located remotely via a field network. Today’s
controllers have extensive computational capabilities and, in addition to proportional, integral, and
derivative (PID) control, can generally perform logic and sequential control.
DCSs may employ one or several workstations and can be configured at the workstation or by an
off-line personal computer.
www.plcscada.com
28
DCS
• Typically dedicated to a particular process
• More attention to safety (e.g. ATEX) -large
areas, less operators- and redundancy
• A PLC can be integrated in a DCS
• With peripherals and real-time Ethernet, the
architectural differences between PLC and
DCS decrease
• PLC -> Logic Controller, factory automation
• DCS -> Process Controller, expensive
• A PLC stand-alone is also called DDC
(Direct Digital Control)
• A DCS could integrate a SCADA
(warning with ambiguity for the more general
meaning of term DCS)
www.plcscada.com
29

Automation Hierarchy 1.4 Hiérarchie de l`automation Leitsystem

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