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PID Control for the future

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

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PID Control for the future

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  1. PIDControlfor the future Haruo TAKATSU Yokogawa Electric Corporation

  2. Agenda

  3. 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 Controlblock in DCS • 3. Whatare 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.298-305 (1999)

  6. PID Control Structure - Derivative Action -

  7. Control Blockin DCS

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

  9. PID Alternatives - Adaptive / Self-Tuning Control

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

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

  12. PID Alternatives - IMC Control -

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

  14. + + Kc(1+TPs) 1+λTPs SV MV + - PV P(s) KPe-Lps 1+TPs Internal Model Control 2012.1.6 - 20

  15. PID Tuning Method - IMC Method -

  16. K=Process Gain, td=Dead time =Time Constant =Desired Closed Loop Response PID Tuning

  17. Loop Details Pane Step Pane Loops Pane Advanced Tuning Pane 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 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 Tuningis always correct ?

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

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

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

  22. 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 What is problem after installation ? • 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

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