## Practical Process Control

### Proven Methods and Best Practices for Automatic PID Control

#### I. Modern Control is Based on Process Dynamic Behavior (by Doug Cooper)

** 1) Fundamental Principles of Process Control**

- Motivation and Terminology of Automatic Process Control
- The Components of a Control Loop
- Process Data, Dynamic Modeling and a Recipe for Profitable Control
- Sample Time Impacts Controller Performance

**2) Graphical Modeling of Process Dynamics: Heat Exchanger Case Study**

- Step Test Data From the Heat Exchanger Process
- Process Gain is the “How Far” Variable
- Process Time Constant is the “How Fast” Variable
- Dead Time is the “How Much Delay” Variable
- Validating Our Heat Exchanger Process FOPDT Model

** 3) Modeling Process Dynamics: Gravity Drained Tanks Case Study**

- The Gravity Drained Tanks Process
- Dynamic “Bump” Testing of the Gravity Drained Tanks Process
- Graphical Modeling of Gravity Drained Tanks Step Test
- Modeling Gravity Drained Tanks Data Using Software

**4) Software Modeling of Process Dynamics: Jacketed Stirred Reactor Case Study**

- Design Level of Operation for the Jacketed Stirred Reactor Process
- Modeling the Dynamics of the Jacketed Stirred Reactor with Software
- Exploring the FOPDT Model With a Parameter Sensitivity Study

#### II. PID Controller Design and Tuning (by Doug Cooper)

**5) Process Control Preliminarie**

- Design and Tuning Recipe Must Consider Nonlinear Process Behavior
- A Controller’s “Process” Goes From Wire Out to Wire In
- The Normal or Standard PID Algorithm

** 6) Proportional Control – The Simplest PID Controller
**

- The P-Only Control Algorithm
- P-Only Control of the Heat Exchanger Shows Offset
- P-Only Disturbance Rejection of the Gravity Drained Tanks

** 7) Caution: Pay Attention to Units and Scaling**

** 8) Integral Action and PI Control**

- Integral Action and PI Control
- PI Control of the Heat Exchanger
- PI Disturbance Rejection of the Gravity Drained Tanks
- The Challenge of Interacting Tuning Parameters
- PI Disturbance Rejection in the Jacketed Stirred Reactor
- Integral (Reset) Windup, Jacketing Logic and the Velocity PI Form

** 9) Derivative Action and PID Control**

- PID Control and Derivative on Measurement
- The Chaos of Commercial PID Control
- PID Control of the Heat Exchanger
- Measurement Noise Degrades Derivative Action
- PID Disturbance Rejection of the Gravity Drained Tanks

**10) Signal Filters and the PID with Controller Output Filter Algorithm**

- Using Signal Filters In Our PID Loop
- PID with Controller Output (CO) Filter
- PID with CO Filter Control of the Heat Exchanger
- PID with CO Filter Disturbance Rejection in the Jacketed Stirred Reactor

#### III. Additional PID Design and Tuning Concepts (by Doug Cooper)

**11) Exploring Deeper: Sample Time, Parameter Scheduling, Plant-Wide Control**

- Sample Time is a Fundamental Design and Tuning Specification
- Parameter Scheduling and Adaptive Control of Nonlinear Processes
- Plant-Wide Control Requires a Strong PID Foundation

**12) Controller Tuning Using Closed-Loop (Automatic Mode) Data**

- Ziegler-Nichols Closed-Loop Method a Poor Choice for Production Processes
- Controller Tuning Using Set Point Driven Data
- Do Not Use Disturbance Driven Data for Controller Tuning

**13) Evaluating Controller Performance**

#### IV. Control of Integrating Processes (by Doug Cooper & Bob Rice)

**14) Integrating (Non-Self Regulating) Processes**

- Recognizing Integrating (Non-Self Regulating) Process Behavior
- A Design and Tuning Recipe for Integrating Processes
- Analyzing Pumped Tank Dynamics with a FOPDT Integrating Model
- PI Control of the Integrating Pumped Tank Process

#### V. Advanced Classical Control Architectures (by Doug Cooper & Allen Houtz)

**15) Cascade Control For Improved Disturbance Rejection**

- The Cascade Control Architecture
- An Implementation Recipe for Cascade Control
- A Cascade Control Architecture for the Jacketed Stirred Reactor
- Cascade Disturbance Rejection in the Jacketed Stirred Reactor

**16) Feed Forward with Feedback Trim For Improved Disturbance Rejection**

- The Feed Forward Controller
- Feed Forward Uses Models Within the Controller Architecture
- Static Feed Forward and Disturbance Rejection in the Jacketed Reactor

**17) Ratio, Override and Cross-Limiting Control**

- The Ratio Control Architecture
- Ratio Control and Metered-Air Combustion Processes
- Override (Select) Elements and Their Use in Ratio Control
- Ratio with Cross-Limiting Override Control of a Combustion Process

**18) Cascade, Feed Forward and Three-Element Control**

- Cascade, Feed Forward and Steam Boiler Level Control
- Dynamic Shrink/Swell and Steam Boiler Level Control

#### VI. Process Applications in Control

**19) Distillation Column Control (by Jim Riggs)**

- Introduction to Distillation Column Control
- Major Disturbances & First-Level Distillation Column Control
- Inferential Temperature & Single-Ended Column Control
- Dual Composition Control & Constraint Distillation Column Control

**20) Discrete Time Modeling of Dynamic Systems (by Peter Nachtwey)**

**21) Fuzzy Logic and Process Control (by Fred Thomassom)**