Prerequisites: This lesson is designed for participants familiar with the basics of instrument control including the proportional, integral, and derivative control modes.
Description: This lesson explains tuning methods and principles behind the three methods of tuning a controller: ultimate, reaction curve, and trial and error. The lesson presents the characteristics of a properly timed process response and relates these to proportional, integral, and derivative control actions. In addition, step-by-step procedures for tuning controllers using each method are demonstrated.
- Define controller tuning and its purpose as used in a process control system
- Define a process response
- Explain the significance of a 1/4 decay reaction curve
- Perform the preliminary steps for tuning a controller
- Stabilize a process on manual control before using the ultimate method
- Obtain the value of and calculate the proper setting for a proportional band or gain
- Find the value of the ultimate period
- Calculate the proper settings for PI, PD, and PID controllers
- Verify adjustments
- Obtain and interpret a process reaction curve
- Calculate the process gain, dead time, time constant, and controller settings using the reaction curve method
- Interpret a process response to determine the proper setting
- Using the trial and error method, tune the proportional mode