How to Convert Cable Size from AWG to Inches
How to Convert Cable Size from AWG to Inches ? Here is the formula for conversion of cable size from American wire gauge to inches. The diameter of a Number…
Cascade Control
A simple control system drawn in block diagram form looks like this: Information from the measuring device (e.g. transmitter) goes to the controller, then to the final control device (e.g.…
Supervisory Control
In a manually-controlled process, a human operator directly actuates some form of final control element (usually a valve) to influence a process variable. Simple automatic (“regulatory”) control relieves human operators…
Tuning a Temperature Process Control Loop
Tuning a Temperature Process Control Loop Ziegler-Nichols open-loop tuning procedure This next simulated process is a temperature control process. Performing an open-loop test (two 10% increasing output step-changes, both made…
Tuning a Liquid Level Process Control Loop
Ziegler-Nichols open-loop tuning procedure The next simulated process I attempted to tune was a liquid level-control process. Performing an open-loop test (one 10% increasing output step-change, followed by a 10%…
Features of PID Controller actions
Purpose of each Controller action Proportional action is the “universal” control action, capable of providing at least marginal control quality for any process. Integral action is useful for eliminating offset…
PID Tuning Recommendations based on Process Dynamics
Knowing which control actions to focus on first is a matter of characterizing the process (identifying whether it is self-regulating, integrating, runaway, noisy, has lag or dead time, or any…
Heuristic PID Tuning Procedure
From the initial open-loop (manual output step-change) test, we could see this process contains multiple lags in addition to about 2 minutes of dead time. Both of these factors tend…
Ziegler-Nichols Closed Loop Tuning Procedure
The closed-loop, or “Ultimate” tuning method of Ziegler and Nichols was applied to this process. Eliminating both integral and derivative control actions from the controller, and experimenting with different gain…
Ziegler-Nichols Open Loop Tuning Procedure
The first process tuned in simulation was a “generic” process, unspecific in its nature or application. Performing an open-loop test (two 10% output step-changes made in manual mode, both increasing)…
