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What is Feed-Forward Control?
In a previous post cascade control was introduced as an effective means of limiting the lag between an upset and the associated PID control loop’s correction. As practitioners know: The longer the delay in responding, the larger the negative impact on a process. Like cascade, Feed-Forward enables the process to preemptively adjust for and counteract the effects of upstream disturbances.
What is Proportional-Only Control? When Should P-Only Control be Used?
Place in Industrial Process Control.
As with most everything in process manufacturing, PID controllers require practitioners to make choices. One of those choices is which form of the controller to apply on a given regulatory control application. In a previous post the pros and cons of Derivative and the full PID were covered, and now the advantages and disadvantages of Proportional-Only control are explored. Due to performance characteristics the selection of a P-Only controller can be relatively straightforward and among a practitioner’s easier choices.
How Do I Tune a Temperature Loop?
Temperature is one of the more common types of self-regulating – also known as non-integrating – processes used in industry. Like other self-regulating loops, temperature loops tend to naturally settle at a new operating state when adjustments are made to the corresponding Controller Output. What’s more, temperature loops are nonlinear in their behavior and process dynamics can vary considerably from one range of operation to the next.
What Sample Rate is Needed When Tuning PID Controllers?
Practitioners often apply simple guidelines when it comes to data collection requirements and controller tuning. These “rules of thumb” assure that sufficient data resolution exists when a given PID control loop’s dynamics are being analyzed. Without good data a process engineer’s ability to model the dynamics and tune for improved control can be undermined. If the sample rate is too slow, then most any tuning procedure will be hit-or-miss at best. So what exactly are those guidelines?