1. Yokogawa Electric Corporation
PID Control for the future
Haruo TAKATSU
Yokogawa Electric Corporation

2. Agenda

3. 1. Will PID control continue to be used in the future ?
Discussion Items
1. Will PID control continue to be used in the future ?
Market Survey in Japan
2. When and why is derivative action used ?
Flexibility of PID Control block in DCS
3. What are alternatives ?
Self-Tuning / Adaptive Control, Internal Model Control
4. What is your favorite tuning method ?
PID Tuning in our system
5. Do we know everything about PID or are there any research needs ?
Introduce Monitoring & Diagnosis

4. Needs of PID Control
- SICE Report -

5. Control Technology Survey
Takatsu, H., Itou, T. : Future Needs for Control Theory in Industry
　– Report of the Control Technology Survey in Japanese Industry,
IEEE Transaction on Control Systems Technology, 07, 03 pp (1999) 5

6. PID Control Structure
- Derivative Action -

7. Control Block in DCS

8. PID Control ＋ PID ＋ PI-D ＋ I-PD - - - Process Process Process SV PV MVDV ＋ -
PID PV DV
Process SV MV ＋ -
PI-D
I-PD
Process SV PV MV ＋ - DV
Page 8

9. PID Alternatives
- Adaptive / Self-Tuning Control

10. Self-Tuning Control Estimated Model Model Estimation PID Control
Process
Response Monitoring
Model Estimation
Estimated Model
PID Tuning MV PV SV
PID parameters

11. - Nonlinear Programming -
Self-Tuning Control
In case oscillating and small overshoot,　
Increase/Decrease P and decrease I.
In case large overshoot and fast convergence,
Increase/decrease P & I.
In case No oscillation, slow convergence,
Decrease P &I.
In case slow oscillation and convergence, Decrease P and increase I.
- Nonlinear Programming -
Reflection: Xref = (1+a)Xbar -aXmax
Expansion: Xexp= bXref+(1-b)Xbar
Xmid
Xmax
Xmin
Xref
Xexp
Xbar
Xmax
Xmid
Xred
Reduction
Xcon
Xmin
Xmax
Xmid
Contraction:
Xcon= cXmax+(1-c)Xbar
・SIMPLEX法
Xred

12. PID Alternatives
- IMC Control -

13. Internal Model Control+ - － SV MV PV
C(s)
P(s) DV
PM(s)
Q(s) + - SV MV PV
Q(s)
P(s) DV
PM(s) －
C(s)
Controller：C(s)，　Internal Model： PM(s)，　Process：P(s)　

14. Internal Model Control+ - SV MV PV
P(s)
KPe-Lps
1+TPs
Kc(1+TPs)
1+λTPs

15. PID Tuning Method
- IMC Method -

16. PID Tuning Stable Process PI - PID Integral Process P - PI PID Gain
Reset
Derivative PI -
PID
Integral Process
Gain
Reset
Derivative P - PI
PID
K=Process Gain, td=Dead time
=Time Constant
=Desired Closed Loop Response

17. PID Tuning
The Advanced Tuning window is for user to perform detail analysis of each step test data and confirm the final suitable P, I, D parameters.
most of the important parameters in loop configuration
Loops Pane
Loop Details Pane
Step Pane
Advanced Tuning Pane
the list of steps captured under the selected tag and the preview of the step data
displays loops grouped by the “Location” defined in Loop Configuration
the main window that user does the analysis for model and loop simulation

18. PID Tuning is always correct ?

19. Research & Development in the Future
- Plant Life Cycle Monitoring & Diagnosis -

20. Valve Stiction Results: Oscillating Only
Loop Oscillation & Valve Stiction Dianosis
Valve Stiction Results: Oscillating Only

21. Loop Oscillation & Valve Stiction Diagnosis
Valve Stiction Results: Oscillating & Sticking

22. What is problem after installation ?
Industry has implemented many projects
Shift from project work towards maintenance
Staff is less appealed by maintenance work
Shortage of skilled staff in process control and optimisation
Maintenance can be tedious and time consuming
Too much focus towards Uptime (Online factor)
 Applications do not deliver optimum performance
Reference : - Recent survey of 20,000 loops performance
Excellent 16%
Acceptable 12%
Fair 28%
Poor 11%
Manual mode 33%

23. Thank you for your attention