DWH Technical Topic: Abbott App - Tension Through Speed

By Clarence Klassen,  P. Eng. 

An Abbott App – Tension Through Speed (TTS) - is now available which models a web-tension regulator. The app shows the predicted transient and steady-state tension which will result from a change in tension setpoint. Tension in a span, the drive speed regulator, and Proportional-Integral-Derivative (PID) regulator all contribute to the model. The control block diagram is included.

Inputs include the span length, gauge, width, line speed, modulus of elasticity of the web as well as regulator gains. Two graphs show the Bode Plot and the transient response of the web tension when a step change in tension setpoint is applied. The exponential time constant (CrossOver) and response overshoot is calculated.

There is a lot to be learned by simply changing variables in this app.

Experience

A fairly long tutorial is included with some guidance for tuning a tension regulator provided. This will be a review of your control classes.

Training

Have fun. This app does a lot less damage than running tuning experiments on an operating line. Obtain your best tuning values. Test the robustness of your tuning by changing:

•  Span (ex. Accumulator becomes active)
• Modulus (E) change
• Gauge change
• Speed change
• Drive speed regulator tuning change

The modeling in this app is normally performed using MatLab™ with Control System Toolbox. Kudos to Prof. Abbott for coding in Javascript.

Your comments are welcome.

More info: https://www.stevenabbott.co.uk/abbottapps/TTS/index.html