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

Agenda

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

Needs of PID Control - SICE Report -

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) 5

PID Control Structure - Derivative Action -

Control Block in DCS

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

PID Alternatives - Adaptive / Self-Tuning Control

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

- 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

PID Alternatives - IMC Control -

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)　

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

PID Tuning Method - IMC Method -

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

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

PID Tuning is always correct ?

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

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

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

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%

Thank you for your attention