بسم الله الرحمن الرحيم Advanced Process Control Lecture one

1. بسم الله الرحمن الرحيمAdvanced Process ControlLecture 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

2. 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

3. 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)

4. Syllabus • MIMO control topics • Centralized and decentralized control • Interaction and relative gain array • Design of static and dynamic decoupler • Predictive control (DMC)

5. Marking Scheme & Reference Books • Marking scheme • Mid-term exam: 35% • Final exam: 40% • Homework: 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, Springer, 2006.

6. Structures Objectives 01_1 Control objectives and structures Safety Environmental protection Equipment protection Smooth plant operation and production Product quality Profit optimization Feedback Feedforward Feedback/Feedforward Cascade

7. Final Control Element Controller Sensor Transmitter Controller Sensor Final element Manipulated variable Controlled variable Process Disturbances Other outputs Feedback control

8. Disadvantages Advantages 01_1 Advantages and disadvantages of feedback control • 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

9. 01_4 Feedforward control

10. Disadvantages Advantages 01_1 Advantages and disadvantages of feedforward control • 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

11. 01_5 Feedback / feedforward control

12. 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.

13. Cascade Control (a process example)

14. Cascade Control (a process example)