Report on Basic Feedback Control Education and a Practical PID Tuning Method for Technical Staff and Operators

Abstract

Proportional–integral–derivative (PID) control is a technique commonly used in the process industry. Although an introduction to PID control is referenced in many textbooks, practical PID tuning techniques applicable to the manufacturing field have not yet been established. As a result PID controllers are often tuned through the experience and intuition of technical staff and operators. In this paper, we introduce a basic PID control lecture outline which avoids complex numerical formulas. In our lectures, trainees can visually learn PID control using a PID Excel simulator, able to simulate process behavior in the case of control parameters changes.Generally, PID tuning techniques are divided into two categories; open-loop and closed-loop types. In the open-loop type, a step response test is required for PID tuning. From this test, the process gain Kp, dead time L and the time constant T are obtained to determine the PID parameters. In practice, step response tests are rarely implemented in the manufacturing field, due to their direct disturbance to production activity. As an alternative method, PID parameters can be determined through consistent oscillation using proportional control alone in a closed loop. However, as consistent oscillation potentially damages the plant facility, this PID tuning method is also not accessible in the field. Therefore, we propose a practical PID tuning method using damped oscillation generated by proportional control. We believe that in light of advanced automatic PID tuning systems utilizing AI technology being introduced in the near future, current service business development in this sector has a tendency to hide the underlying basic technology. To prevent the future industry from becoming blind to basic process control technology, we aim to contribute to the transfer of PID parameters tuning techniques to technical staff and operators working in plants.