š Key Concepts
ā¢ PID controller basics ā what each term (P, I, D) actually does to the control signal
ā¢ The difference between error, output, setpoint, and input in a control loop
ā¢ How a proportional relationship is normally defined in control theory
š Think About
ā¢ For each choice, ask: in a standard PID loop, what is this component mathematically based on ā the error, the integral of error, or the derivative (rate of change) of error?
ā¢ Focus on what a derivative term responds to: is it changes in the output, or changes in the error signal?
ā¢ Think about the proportional term: when we say something is proportional, which two quantities are directly related in basic control action?
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Before You Answer
ā¢ Be clear that in most textbook PID definitions, all three terms act on the error (setpoint ā measured value), not directly on the process output itself
ā¢ Verify which option correctly describes a linear/proportional relationship between two variables, without swapping which is input and which is output
ā¢ Check that the description of the integral term involves accumulation over time, not an instantaneous one-to-one proportionality