Posts Tagged ‘control loop’
What Is a Set Point Filter?
Names – like looks – can be deceiving. While jumbo shrimp are big relative to other shrimp there’s very little about them that could be considered gargantuan. So there should be no surprise to learn that in the realm of process control a Set Point Filter has nothing to do with filtering noise within a control loop’s data.
Read MoreHow Does the Derivative Term Affect PID Controller Performance?
Derivative is the third term within the PID. In mathematical terms the word derivative is defined as the slope of a curve. Seen in the context of strip chart data derivative represents the rate of change in error – the difference between the Process Variable (PV) and Set Point (SP). Like the proportional and integral terms within a PID controller, the derivative term seeks to correct for error. Valuable as the third term can be in maintaining effective control, experience suggests that appropriate uses of derivative are not entirely clear.
Read MoreHow Do I Calculate Gain? What Is the Difference Between Process Gain and Controller Gain?
Among practitioners who tune PID control loops manually most note their focus on calculating the Gain. Process Gain is a model parameter whereas Controller Gain is a tuning parameter. The former describes important aspects of a given process’ dynamic behavior. The later contributes to the PID controller’s responsiveness to disturbances.
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