Fundamentals of PID Control

Anthony K. Ho, P.E.

Course Outline

The course starts by introducing the basic theory behind PID control. Then, it is followed by two major types of controls: open-loop and close loop controls. Tuning the three constants in the PID controller algorithm is a very important concept of any PID application; therefore, PID tuning will be focused. Examples will be used throughout the course for engineers to understand the steps to implement and tune PID controllers.

The intention of this course is to help you understand how most PID controllers work, which will provide you the basic knowledge to perform the task.

This course includes a multiple-choice quiz at the end, which is designed to enhance the understanding of the course materials.

Learning Objective

At the conclusion of this course, the student will acquire the following specific knowledge and skills:

• History of PID Control;
• Background of PID Control;
• Theory of PID Control;
• Function Block Diagram and Pseudo Code of PID Algorithm;
• Open-loop vs. Closed-loop Control;
• Different Methods of PID Tuning;
• How to Implement PID Control;
• Example - PID Controller for DC Motor; and

Intended Audience

This course is intended for control systems, electrical, and industrial engineers.

Benefit for Attendee

Attendee of this course will be able to understand the concept of PID control application and the steps to implement and tune PID controllers.

Course Introduction

PID control is used to control and maintain processes. It can be used to control physical variables such as temperature, pressure, flow rate, and tank level. The technique is widely used in today’s process industry to achieve accurate control under different process conditions. PID is an algorithm that the controller uses to evaluate the controlled variables.

Course Content

The course content is contained in the following PDF file:

Course Summary

The proportional, integral, and derivative terms are used to calculate the output of the PID controller. Therefore, the proportional, integral, and derivative gains must be chosen correctly for the control loop to be stable. The process of adjusting these control parameters to the optimum values is called tuning the control loop. Stability is a basic requirement, if the parameters are chosen incorrectly, the controlled process input can become unstable, i.e. its output diverges, with or without oscillation, and is limited only by saturation or mechanical breakage. Instability is caused by excess gain, particularly in the presence of significant lag. Performance can generally be improved by careful tuning. PID tuning is a difficult problem, even though there are only three parameters and in principle is simple to describe, because it must satisfy complex criteria within the limitations of PID control. There are various methods for loop tuning, and more sophisticated techniques are provided by different PLC controller vendors. This course describes most common methods for loop tuning.

For additional technical information related to this subject, please visit the following websites or web pages:

Control Tutorials for Mathlab: PID Tutorial
Proportional-Integral-Derivative PID Controls
Virtual PID Controller Laboratory : PID Design & Tuning

Quiz

Once you finish studying the above course content, you need to take a quiz to obtain the PDH credits.

DISCLAIMER: The materials contained in the online course are not intended as a representation or warranty on the part of PDH Center or any other person/organization named herein. The materials are for general information only. They are not a substitute for competent professional advice. Application of this information to a specific project should be reviewed by a registered architect and/or professional engineer/surveyor. Anyone making use of the information set forth herein does so at their own risk and assumes any and all resulting liability arising therefrom.