Transcript 01_1
بسم هللا الرحمن الرحيم
Advanced Process Control
Lecture one
1- Syllabus, Marking Scheme and Reference Books
2- Introduction to Single Input – Single Output Control (SISO)
- Feedback Control
- Feedforward and Cascade Control
Lecturer: M. A. Fanaei
Ferdowsi University of Mashhad
1
Syllabus
Review of SISO control
Introduction to feedback control theory
Process modeling
Control valve characteristics
Types and modifications of PID controllers
Tuning of PID controllers (offline and online)
Discrete version of PID controllers
Dynamic simulation and control of chemical processes using
MATLAB/SIMULINK
2
Syllabus
Advanced SISO control topics
Performance and robustness
Cascade control
Feedforward control
Ratio, Override and Selective Control
Predictive control (IMC and Smith predictor)
State-space model (Continuous and Discrete)
3
Syllabus
MIMO control topics
Centralized and decentralized control
Interaction and relative gain array
Design of static and dynamic decoupler
Predictive control (DMC)
4
Marking Scheme & Reference Books
Marking scheme
Mid-term exam:
Final exam:
Homework:
35%
40%
25%
Reference books
C. A. Smith and A. Corripio, Principles and Practice of Automatic Process
Control, 3rd edition, Wiley, 2006.
K. J. Astrom and T. Hagglund, Advanced PID Control, ISA, 2006.
T. E. Marlin, Process Control: designing processes and control systems for
dynamic performance, 2nd edition, McGraw-Hill, 2000.
K. Ogata, Modern Control Engineering, 3rd edition, McGraw-Hill, 1997.
K. J. Astrom and B. Wittenmark, Computer Controlled Systems, 3rd edition,
Prentice Hall, 1997.
C. C. Yu, Autotuning of PID controllers: A relay feedback approach, 2nd edition,
5
Springer, 2006.
Control objectives and structures
Safety
Environmental protection
Equipment protection
Smooth plant operation and production
Product quality
Profit optimization
Structures
Feedback
Feedforward
Feedback/Feedforward
Cascade
Objectives
6
Feedback control
Final Control
Element
Controller
Sensor
Transmitter
Controller
Final
element
Sensor
Manipulated variable
Controlled
variable
Process
Disturbances
Other outputs
7
Advantages and disadvantages of feedback control
Disadvantages
• Very simple technique
• Effective for all disturbances
• Provides zero ss offset
• Works with minimum knowledge
of the process
• Does not take control action
until the process output has
deviated from set point
• Affects the closed-loop
stability
Advantages
8
Feedforward control
9
Advantages and disadvantages of feedforward control
Disadvantages
• Compensates for a disturbance
before the process output is
affected
• Does not affect the stability of
the control system
• Can not eliminate steady-state
offset
• Requires a sensor and model
for each disturbance
Advantages
10
Feedback / feedforward control
11
Cascade Control
When the simple feedback control structure don’t have an
acceptable performance, a cascade structure may improve
the performance (speed up the closed loop response).
A cascade structure can be used, when a process has some
series dynamics and the output variables between theses
dynamics can be measured.
12
Cascade Control (a process example)
13
Cascade Control (a process example)
14